Diseño tanque elevado y resortes con staad pro

STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING

ELEVATED INTZ TANK MODELING , LOADINGS , ANALYSIS AND DESIGN OF ELEVATED INTZ TANK

Modeling: 1.

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Space-file name : RC NTZ TANK Unit-Met, Kn Add beam Finish View from +Z –X_Y Plane .Snap Node/Beam Use Circular Repeat tool.

T.RANGARAJAN, STRUCTURAL ENGINEER

STAADPRO

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING

Snap Node/Beam

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STAADPRO

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING

Insert node- vertical side into 2 and to Slope by 3.

Use circular repeat tool to model the tank.

p

T.RANGARAJAN, STRUCTURAL ENGINEER

STAADPRO

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING

Select all beams and choose Create Infill Plate PLATE ELEMENTS. (Plate member)

to Infill plate tool and fill with

Structure Diagrams… and click to Fill Plates

Ctrl+Z ….Undo ….. Circular Repeat

T.RANGARAJAN, STRUCTURAL ENGINEER

STAADPRO

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING

Circular Repeat

Create Infill Plate Label tool….

Structure Diagrams… Fill Plates Select Beam Cursor and select beams and click fill plates to view the plates.

General menu- property- 200 mm for plate and provide Fixed Support to the bottom 2 nodes as shown.

T.RANGARAJAN, STRUCTURAL ENGINEER

STAADPRO

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING

Load case 1 : Water Pressure-General - Add.. Plate Loads | Hydrostatic - Select Plate(s).

T.RANGARAJAN, STRUCTURAL ENGINEER

STAADPRO

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING W1 = -20Kn/m2 and W2 = 0 Kn/m2.

Select Hydrostatic and enter ,W1 = -40 Kn/m2 and W2 = -20 Kn/m2

W1 = -50 Kn/m2 and W2 = -4 0Kn/m2 T.RANGARAJAN, STRUCTURAL ENGINEER

STAADPRO

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING

Select Plate Cursor and select the plates . Use Circular Repeat

T.RANGARAJAN, STRUCTURAL ENGINEER

STAADPRO

as shown.

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING Local Z --- Ctrl+Z ……. Circular Repeat …

CommandAnalysis/Print .. Print Option .No Print Choose Analyze | Run Analysis…

Choose Post-processing - Plate | Contour …choose Max Absolute

View From +Y … Plate Cursor

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STAADPRO

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING

Use Cut Section … Select to View ......... View Highlighted Only

View From +Z … Plate Cursor

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STAADPRO

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING Cut Section … Select to View | View Highlighted Only

Cut Section …

Modeling …. View From +Z

Show All Surface Element and Plate Element

Cut Section …Select to View | View Highlighted Only

View From +Y……

……..

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STAADPRO

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING Define Mesh Region ……. Div. = 1

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STAADPRO

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING Support …………. Fixed Support

General | Property ……. Thickness… Plate/Surface Thickness …0.3 m, Material = Concrete … Add … Close Assign To View …. Assign

Load case 2 : PLATE LOAD … Add.. .Selfweight

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING Add.. Plate Loads | Pressure on Full Plate …Add … Close …Assign To View

Analyze | Run Analysis… Run Analysis Post-processing case2 : PLATE LOAD Plate | Contour

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STAADPRO

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING

Modeling :

1 … (X=2, Y=20, Z=0) (X=0, Y=0, Z=0) …. (Circular Repeat) Modeling …. Geometry | Beam View From +Z …… Snap Node/Beam

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING

Snap Node/Beam Snap Node/Beam …. (X=2, Y=20) … (X=0, Y=0) Property … Define… Rectangle : YD = 1.0 m, ZD = 0.5 m, Material = Concrete

Insert Node

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STAADPRO

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING Circular Repeat

3D Rendering

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING Link beam property …. YD = 0.4 m, ZD = 0.4 m …Beam

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STAADPRO

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING Support …. Edit List

Load case 3 : Design Load …… Repeat Load … L2 : PLATE LOAD … 1.4 Commands | Loading | Load List… L3 : DESIGN LOAD Design | Concrete … Define Parameters…

FC : Compressive strength of concrete = 25 N/m2 • FYMAIN : Yield strength of steel = 415 N/m2 • MAXMAIN : Max. main reinforcement bar = 25 • TRACK = (2)

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STAADPRO

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING View From +Z

Commands… DESIGN COLUMN Analyze | Run Analysis…

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING

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STAADPRO ELEVATED INTZ TANK MODELING AND DESIGNING

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Procedure to Calculate Tributary Area and Vertical Spring Constants for foundation modeled with soil as elastic supports in FE based programs Introduction In Foundations, many times to estimate true behavior of mat; elastic property of soil is taken into consideration in FEM models. The base slab is divided into finite number of 2D plate elements representing the mat and the support condition is elastic based on the modulus of subgrade reaction of soil. Some popular FE programs do not include the facility of surface support and hence to model soil as elastic support, calculation of vertical spring stiffness at each node of the mesh becomes necessary.

The spring value shall be in Force/Unit displacement. The unit of Modulus of subgrade reaction is force/unit area/unit deflection. Hence, when vertical spring constant is to be calculated for each joint, the tributary area of mat at each node shall be calculated and then multiplied with the modulus of subgrade reaction. This procedure is simple for regularly divided meshes. However for most practical problems, it is a cumbersome process to calculate the tributary area at each node and then calculate the spring constants. Also, after the analysis is completed, the output of such programs provides only vertical spring force in force unit. For determination of actual base pressure, it becomes necessary to divide the spring force by the tributary area at each node.

Procedure To simplify the calculation of tributary area and vertical spring constant, a simple, accurate and quicker method is suggested.

STEP 1 – Prepare the model with or without superstructure and the base modeled as 2D plate elements.

STEP 2 – Copy the model and extract the mesh at base by deleting all members/elements above base level.

STEP 3 – Provide PIN support at each node of the base and create two loading cases.

STEP 4 – In Load case 1, apply surface load equal to the magnitude of modulus of subgrade reaction on the base mat and in Load case 2, apply surface load equal to Unity on the mat.

STEP 5 – Run the model for static analysis and print the support reactions.

It is evident that, the vertical support reaction due to uniform surface load will be tributary area multiplied by the surface load. This is nothing but the spring constant when the surface loading is equal to modulus of subgrade reaction and tributary area when surface loading is unity. Thus, we achieved the spring constant and tributary area at each node. In the original model export these values as spring supports by providing appropriate command. Retain the tributary area for future use.

Alternatively, to calculate tributary areas from load case 1 only, STEP 5 – Extract the output of support reaction for load case 1 and import it in the Excel. Divide each reaction by modulus of subgrade reaction. This gives the tributary area at each node.

STEP 6 – After the analysis of entire original model is completed; the support reaction will be spring force at each node of base mesh. To obtain base pressure magnitude, divide each spring force by corresponding tributary area obtained in the STEP – 5.

By: Jignesh V Chokshi L&T Sargent & Lundy Limited, Vadodara

Getting Started December 18, 2013 in STAAD Pro |

STAAD.Pro V8i screen is shown below. The screen has five major elements as shown below.

1. Menu bar.

2. Tool bar.

3. Page control.

4. Main Window.

5. Data Window.

In STAAD.Pro V8i: Geometry is the “Elements of your Structure”. The Elements are given below:    

Nodes Members (beams and columns) Plates (Slab, Walls and Raft Foundations) Surfaces (Slab, Walls and Raft Foundations)

Nodes: Stiffed Joint with 6 reactions. It is located at each end of the Beam and each corner of the Plate Nodes considered the essence of the geometry of any structure in STAAD.Pro. Each node holds the following information:  

Node Number.

Node Coordinates in XYZ space.

Beam: Any member in the structure, that can be beam, column, bracing member or truss member. Beams are actually defined based on the Nodes at their ends. Each beam holds the following information:  

Beam Number.

The Node numbers at its ends.

Plates: A thin shell with 4 node shaped element. It can be slab or wall element. Each plate will holds the following information:  

Plate Number.

Node Number at each corner of it.

Surface: A thin shell in green color with mutli-nodded shape starting from 3 nodes and more. It can be anything of slabs, walls and raft foundations. It holds the following information:

 

Surface Number.

Node Numbers at each corner of it.

Hardware Requirements: The following requirements are suggested minimums. Systems with increased capacity provide enhanced performance.    



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PC with Intel-Pentium or equivalent.

Graphics card and monitor with 1024×768 resolution, 256 color display (16 bit high color recommended).

128 MB RAM or higher.

Windows NT 4.0 or higher operating system. Running it on Windows 95 & Windows 98 systems is not recommended as performance may be degraded. The program works best on Windows 2000 and XP operating systems.

Sufficient free space on the hard disk to hold the program and data files.

The disk space requirement will vary depending on the modules you are installing. A typical minimum is 500MB free space.

A multi-media ready system with sound card and speakers is needed to run the tutorial movies and slide shows.

Starting STAAD.Pro V8i December 18, 2013 in STAAD Pro Creating a Project: Once you stared the STAAD.Pro application follow the instructions:

1. In the Project Tasks box, click New Project.

2. A New Project dialog box appears is shown below:

3. Before starting a project, you must be aware of the type of structure. The structure type can be defined as Space, Plane, Floor, or Truss.    

Space: A SPACE structure, which is a three-dimensional framed structure with loads applied in any plane, is the most general. The loading causes the structure to deform in all 3 global axes.

Plane: The type of geometry, loading and deformation are restricted to the global X-Y plane only.

Floor: The geometry of structure is kept at the X-Z plane.

Truss: The structure transmits loading by pure axial action. Truss members are considered to be in capable of carrying shear, bending and torsion.

4. Set the length units and loading units and click Next button.

Note: The units can be altered later if needed, at any point of the model creation.

5. Now Where do you want to go? dialog box appears. You have specify the method for building

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Add Beam: Sets the program in the Snap Node/Beam dialog and snap grid to construct your model by creating new joints and beams using the construction grid, drawing tools and spreadsheets.

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Add Plate: Sets the program up with the Snap Node/Plate dialog to construct your model by creating new joints and 3-noded and 4-noded plate elements using the construction grid, drawing tools and spreadsheets.

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Add Solid: Sets the program up with the Snap Node/Plate dialog to construct your model by creating new joints and 8-noded solid/brick elements using the construction grid, drawing tools and spreadsheets.

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Open Structure Wizard: Opens the library of readymade structure templates which can be extracted and modified parametric model standard, parametric structural templates for trusses, surfaces, bay frames and much more.

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Open STAAD.Editor: Allows you to build your model using STAAD syntax commands (nongraphical interface) through the STAAD editor.

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Edit Job Information: Automatically opens the Job Information dialog box which provide information about the job (i.e. client’s name, job title, engineers involved, etc.) before building your model.

Methods Of Model Generation December 20, 2013 in STAAD Pro |

STAAD.Pro V8i consists of three parts:   

Pre Processor: Generates the model with all the data needed for the analysis.

Analysis Engine: Calculates displacements, member forces, reactions, stresses, etc.

Post Processing: Displays the results of the analysis and design.

Creating Nodes: When you select the Nodes command in geometry menu, it shows a dialog box where you can enter the joint coordinates.

After creating the joint i.e. entering the coordinates, you can able to see the joint in the modeling area.

JOINT COORDINATES i1, x1, y1, z1, (i2, x2, y2, z2, i3) REPEAT n, xi,yi1, zi1, (xi1, yi2, . . . . xin, yin, zin) REPEAT ALL n,xi1, yi1, zi1, (xi2, yi2, zi2, . . . . xin, yin, zin)

Enhanced Grid Tool:The options in Snap/Grid Node tools in the geometry menu

have been improved to 1. Allow multiple grids to be created.

2. Import a DXF file and use it as be created.

3. Import grid files created in different STAAD.Pro model.

Beams, plates and 8 nodes solid element can be created using the suitable Snap/Grid tool. When this function is propelled, the following dialog is opened which includes a Default Grid. This grid will be of type ‘linear’, there are also options to create Radial, and Irregular grids.

As new grids are added or modified, the information is stored in the STAAD.Pro data folder with a GRD allowance that permits other STAAD.Pro file to re-use these defined grids. To alter the starting of this grid, click on the Edit button to show the existing grid properties.

The current plane of the grid is set by selecting the required option. This can rotated about one of the global planes by selecting the axis of rotation and setting the angle.

The origin of the grid is marked on the graphics, with a small circle. The location of the origin, specified in global coordinates, can either be defined explicitly in the given X.Y and Z coordinates, or it can be set to the coordinates of an existing node by clicking on the icon and then on the node itself in the graphical window. Note that at this point the origin coordinate is updated.

The construction lines are used to specify how many gridlines are created either side of the origin, the spacing between the gridlines and if there should be a skew in degrees along either axis.

Click on the OK button to accept these settings.

Additional grids can be defined by clicking in the Create button. Three different types of standard grid can be created:   

Linear Radial Irregular

The type of the grid required can be selected from the drop down list available at the top of the property sheet.

Each new grid should be identified with a unique name for future reference. The functionality for each type of grid is given below: Linear:   

Two dimensional system of regularity spaced linear construction lines creating a plane of snap points.

Plane is defined as being coincident with the global XY, XZ or YZ planes or at an angle skewed with respect to the global planes.

Location of the origin can be defined with respect to global X, Y and Z coordinates systems.

Radial:    

Two dimensional system of regularly spaced radial and circumferential construction lines creating a plane of snap points.

Plane is defined as being coincident with the global XY, XZ and YZ planes or at angle skewed with respect to the global planes.

Location of the origin can be defined with respect to global X, Y and Z coordinates systems.

Well suited for drawing circular models using piece-wise linear techniques.

The settings for a Radial grid are defined in the following window:

The Plane, Angle of Plane and Grid origin option are as for the linear.

Irregular:  

Two dimensional system of regularity or irregularly spaced linear construction lines creating a plane of snap points.

Plane is defined as being coincident with the global XY, XZ or YZ planes or at an angle skewed respect to the global planes or at an arbitrary plane.

The settings for an irregular grid are defined in the following window:

Translational Repeat December 22, 2013 in STAAD Pro | Translational Option allows to copy the entire structure or a portion of the structure in a linear direction. We may generate one or more several copies of the selected components. Select the structural elements to repeat. Select Geometry→ Translational Repeat option from the geometry menu or Click Translational Repeat Icon shown below:

. The Translational Repeat dialog box appears as

Global Direction: Choose any one of the three possible global direction along which the selected structural elements should be copies.

No of Steps: Specify the numbers of steps to repeated you need.

Default Step Spacing: Type the default spacing between steps in the edit box in current length units. For each step, the default value of the spacing will be what we provide in the Default step spacing box. We can change the spacing of individual steps if we choose to do so.

Step Spacing Table: This table consists of two columns: Step and Spacing. We can change the spacing of any type in the table.

Renumber Bay: This is the way of instructing the program to use a user-specified starting number for the members generated in each step of the translational repeat activity.

Geometry Only: The Translational Repeat allows the copying of the elements without having their loads properties, steel design parameters, etc. being copied with it. By default (when the Geometry Only option is not checked) all loads, properties, design parameters, members releases, etc. on the selected elements will automatically be copied along with the elements. By checking the option labelled Geometry Only, the translational repeating will be per formed using only geometry data.

Link Steps and Open Base: If you want to automatically connect the steps or copies by new members, along the specified global directions, check the Link Steps check box. In other words, the Link Steps option is applicable when the newly created units are physically removed from the existing units and when one wishes to connect those using members. To avoid joining the base of the copied structures, check the Open Base box. Here you can see the Frame model copied using the Translational Repeat option:

Circular Repeat December 22, 2013 in STAAD Pro | Circular Repeat allows to copy of the entire structure on an portion of if in a circular direction. Select the structural elements to repeat and select the Circular Repeat option from the geometry menu. The 3D Circular dialog box appears as shown in the figure.

Axis of Rotation: Click the radio button to choose the axis of rotation for repeating the selected components.

Through: The new highlight node button selects the Node on Plane. Click on this icon to be able to select the node from the main model. Once the cursor changes the shape, simply select a node from the model. The Node and Point boxes will automatically fill up with the correct information.

Otherwise, type an existing Node number or location Point coordinates to define the axis of rotation.

Use this as Reference Point for Beta angle generation. In previous versions of STAAD.Pro, one limitations of the Circular Repeat feature was that the member orientation was not taken into consideration during the circular generation. This limitation has been addressed now.

If the Use this as Reference Point for Beta angle generation switch is turned on, the point through which the axis for circular repeat operation passes will be used as the member reference point for all the generated members. This point along with the local X axis of the generated member will

define the local X-Y plane of the member and hence the member orientation gets automatically set.

Total Angle: Provide the total sweep angle of rotation between the original structure and the last copied structure.

No of Steps: Provide the number of steps we want over the specified Total Angle.

Link Steps and open Base: If you want to automatically connect the steps by new members, check the Link Steps check box.

To avoid joining the base of the copied structure, check the Open Base box.

The Circular Repeat. Rotate and Mirror dialog boxes have been enhanced to remain open so that the selection beams, nodes, etc. can be accomplished even while the box is open. Also, selection of critical points such as the node, point or plane where the axis of rotation crosses can now be selected graphically while the box remains open. This eliminates the inconvenience in the past where if this location was known before selecting one of the geometry options, the box had to be closed down to determine the location first.

1. Select the objects to be copied.

2. Click Geometry→ Circulation Repeat.

3. In 3D Circular dialog box, select the Axis of Rotation and Point or Coordinate of Axis.

4. Type the Total angle and No of Steps.

5. Click OK.

Insert Node December 23, 2013 in STAAD Pro | This facility allows the user to insert node on an existing member. The member is split into the corresponding number of segments with automatic generation of node and member numbers, member properties and loads.

If you choose this option, the Insert Node cursor appears. By using that cursor, you can select the member to split. The Insert Node dialog appears, as shown below:

Beam Length: This lists the distance from node A to node B along the beam to be split.

New Insertion Point: Provide the Distance from the start node of the member in current length units. Alternatively, provide Proportion of the total length of the member to position the new node. Click Add New Point to add the node.

Add New Point: After providing the Distance or the Proportion, click on the Add New Point to add the node.

Add Mid Point: To split the member into two segments, click on this button.

Add n Points: To divide the beam in a number of equal segments, provide the number of intermediate points in the n = edit box and click on Add n Points. Note that this value should be an integer.

Insertion Points: The locations of the newly created points are listed in this list box, shown as the distance from the start node of the member, To accept the new nodes that appear in the Insertion Point list box, click the OK button.

Remove: To remove a node from the list of inserted nodes, highlight the desired node and click on this button.

Enhancement of Insert Node Operation: Users can now select multiple members and split the members at a given fractional position or a specified distances from the starting node positions. The new feature will enable the users to perform the operation in one sight command which will reduce the modelling time.

New point by distance: Specify the distance in current length units at which the beam is to split. The value for the distance is entered in the Distance edit box and is measured from the start node of the beam.

New point by proportion:

This option allows the users to specify the distance in terms of a ratio. For example, to split a beam at the midpoint, enter 0.5 as the proportion .To split the beam at quarter points, use a proportion value of 0.25.

Add mid point: The beam are split at their midpoints.

Add ‘n’ points: To split a beam by inserting ‘n’ number of points, use this option. The beams are split up into n+1 segments.

Add Beam December 23, 2013 in STAAD Pro | This option in geometry menu allows you to add members by connecting existing nodes. Choosing this option brings up the following sub-menu.

Add Beam from Point to Point: In prior versions to STAAD.Pro, the Add Beam option was a facility for adding a beam between two existing nodes. This has now been extended to be able to create beams from nodes that have not been previously defined. The nodes can now be dynamically generated at the time of creating the beam similar to the way beams are created using the Snap/Grid Beam command.

To create a beam dynamically without the start and end nodes defined, go to Geometry|Add Beam|Add Beam from Point to Point from the main menu. The Add Beams cursor appears. Click on any point on the existing beam where the starting node of the new beam will lie. if an existing node is not present at that point, a dialog box will prompt for a new node to be created.

Click on Yes to create a new node. The Insert Nodes dialog box will prompt for the exact location where the nodes is to be created. once the desired node or nodes have been input that box, click on the OK button to generate the new nodes on the selected beam. If the new node input is not within a close proximity of the point clicked on the screen, no “draggable�line will be shown. Click on the new node to start the creation of the beam. Then, drag the mouse to another existing node location or repeat the same steps again to dynamically create another new node.

Run Structure Wizard December 23, 2013 in STAAD Pro | The Run Structure Wizard option offers a library of ore-defined structure prototypes, such as Pratt truss, North light Truss, cylindrical Frame, etc. We may parametrically generate a structural model and then transfer and superimpose it on the current structure.When we select the Run Structure Wizard option from the Geometry menu, the Structure Wizard window appears as shown below.

The Protype Models and Saved User Models options on the top of the left side of the screen. If the Prototype Models option is selected, the Model Type will list the types of prototype structure available as shown below. If the Saved User Models option is selected, the Model Type will display the list previously done and saved models by the user.

Adding and Deleting items to the library: Items can be deleted or added with certain settings from and to the list. The modified item list can be saved in different files and called when requires. In brief , the item list is customizable.

To insert any customized item under any Model type, select that Model Type and click the mouse at the bottom of the same pane. Right-click the mouse and from the context menu, select Add Plug-in and you can load the corresponding “.dll” file. We can also delete a particular structural item by selecting that particular item and by clicking the Delete Model Plug-in from the context menu. A structural item under any Model Type may be renamed by using Rename Model Generator from the context menu.

The customized list of the Prototype can be saved in different files. By default, STAAD.Pro/Structure Wizard uses the default .STP file. We can save any changes in this file.

Also changes can be saved in any file other than default .STP. To save the changes, select Save As…. from the File menu in the Structure Wizard window. Provide the path and name of the .STP file and press OK.

To open any .STP file to use the customized Structure Libraries, select the File|Open menu option from Structure Wizard main menu. Specify the path and name of the .STP file and press OK. Use the View, Zoom, Pan and Rotate icons to change the orientation of the model.

Generation of Structure from Models December 23, 2013 in STAAD Pro | In this section, the process of generating a structural model and combining it with the existing STAAD.Pro structure will be explained using a Howe Roof Truss. Follow these steps to create the other truss types also.

Selection of Unit: The unit of the length should be specified before the generation of a model. From the File menu, click Select Unit and the Select Unit dialog box will appear as shown below. We can select any unit of length from Imperial or SI/Metric system of units.

Model Type: Truss Select the Howe Roof structure type under model type Trusses. Drag the item into the right side window and release the button. The Select Parameters dialog box will appears to specify the Truss parameter as shown below:

After defining the parameters click Apply and the prototype truss will appears with the X, Y and Z axes on the screen.

Right click in the right side window containing the generated model. The context-menu will display the options Change Property, Scale and Delete. We can edit the value of the parameters by clicking the Change Property, which will pop-up the select Parameters dialog box. Enter the length, height and width of the truss and the number of bays along those directions. To modify the spacing of individual bays, click the browse button and in the dialog box that appears, type new spacing and click OK. Click the Apply button to parametrically generated the truss model.

Click Close to finish.We can re-scale the model in X, Y and Z directions separately using Scale from the context menu. You can also delete the particular model by clicking Delete from the context menu.

Merging the Generated Model to STAAD.Pro Select the Merge Model with STAAD.Pro sub menu from the File menu to combine the generated model. to the current STAAD.Pro structure

The structure Wizard window will now close. In the STAAD.Pro window, the Paste Prototype Model dialog box will appears., in which we can type the shift of the origin of the Structure Wizard model from the origin of the STAAD.Pro axis system or we can type coordinate of the node of the STAAD.Pro structure with which we can want to connect the Structure Wizard model or click on the Reference Pt button to connect the node of the existing structure in STAAD.Pro with the Structure Wizard model by clicking on the joints where they will be connected. Click OK to finish.

In the Frame Models Continuous Beam, Bay Frame, Grid Frame and Floor Grid have similar parameters in the Select Parameter dialog box. Type values for Length, Height & Width and number of bays for each. To modify the spacing of the bays, click the browse button and in the dialog box that appears, type new spacing and click OK. Click the Apply button to the parametrically generated model.

The Cylindrical Frame, Reverse Cylindrical Frame and Circular Beam have similar Parameter in the Select Parameter dialog box. Type values for Length, Radius, Angle and number of bays along length and periphery. To modify the spacing of bars, click the browse button and in dialog box that appears, type new spacing and click OK, Click the Apply button to parametrically generate the model.

Support Specification This allows the user to define the support conditions of the structure by providing fixed, pinned, roller, inclined, spring supports, etc. Supports can defined and assigned from the General| Support page also. This menu option is used to specify the supports on the structures. The Support Specification menu offers several sub-menu options, as follow.

Click Commands→ Support Specifications.

Pinned: This allows user to create the pinned support tag and assigned it to the selected nodes. A pinned support is restrained in all three translational degree of freedom and free in the 3 rotational degrees of freedom

Fixed: This allows the user to create a fixed support tag and assign that to the selected nodes. A fixed support is restrained in all 6 degree of freedom.

Fixed But / Spring: This allows the user to create various types of roller, hinge and spring support with specified restrained degrees of freedom and to assign them to selected nodes.

Enforced: The Enforced support is the same the fixed support except that the restrained degrees of freedom are defined in terms of being stiff springs. Enforced supports are identical to the ‘FIXED’ type of supports in most respects. The real advantage of using the ENFORCED type lies in the fact that is enables STAAD to accept loads such as support displacements loads in case of plates and solids. Support displacement loads are not permitted for plates and solids if the FIXED support type is used. So, for structures without these characteristics, the FIXED type of support offers the same level of functionality as the ENFORCED support type.

Enforced But: Enforced But support type is the same as the “Enforced” support except that we have the choice on the degrees of freedom we wish to restrain. For example, we can select Enforced But and restrain just the FX, FY and FZ degree of freedom and let the remaining 3 free to deformation.

Inclined: This allows the user to create supports that restraints in an axis system that is inclined with respect to the global axis system. There are two aspects defining the inclined supports:  

The reference point which inclined axis system.

The restraints, releases and springs.

Foundation: To define a spring support for an isolated footing, click the Footing radio button. Provide the dimension of the footing in current units settings and choose the Direction of the spring action.

Provide the soil Sub-grade value in the edit box. Click the Add button to add the foundation support tag to the structure or click Assign to assign this support to selected nodes.

Elastic Mat: In this method, the area is calculated using a Delaunay triangle principle. Hence the candidates for this options are nodes which define the mat. To achieve best results, one needs to ensure that the contour formed by the nodes form a convex hull.

Plate Mat: If the foundation slab is modeled using plate elements, the spring supports can be generated using an influence area calculated using the principles used in determining the tributary area of nodes from the finite element modelling standpoint. Hence the candidates for this option are the plates which define the mat. When the mat is modeled using plates. this produces superior results than the ELASTIC MAT type.

Support Page December 23, 2013 in STAAD Pro When the General | Support Page is opened, a Supported Nodes tables and a Supports dialog box appears in the data area. We may specify supports in two ways. We must first create Support Specification and then select the nodes to which this support is to be attached to.

Alternatively, we may first select the nodes and then specify a support to be assigned to the selected nodes. In second case, a new Support Specification is created along with a support reference number. Also note that the Assign button become active if we have already selected the nodes to which the support is to be applied.

Supported Nodes Table list all nodes for which supports have been defined. The type of support is also displayed. The Supports dialog box allows us to define supports and assign them to nodes. All supports that have been defined for the model are listed in the Supports dialog box.

Create: The Create button is for creating the supports to be applied on the structure. When you click this button Create Support dialog box appears.

Edit: For certain types of supports, the parameters of the support can be modified after the support is created. The Edit button is available for that purpose. To do this, first select that support type from the list. Click on Edit and dialog box corresponding to that support will be re-displayed, allowing for changes to be made.

Delete: Use this button to delete a previously assigned support.

Assignment Method: The options under the Assignment Method offer different choices for assigning supports to the structure.

Assign To Selected Nodes: To assign a support to selected nodes, first select the support from the supports dialog box. The support selected is highlighted. Then select the nodes to which this support is to be assigned.

When all the desired nodes are selected, click the Assign To Selected Nodes radio button, then click the Assign button.

Assign To View: To assign a support to all free nodes in a view, first select the support from the Supports dialog box. The selected supported is highlighted. Select the Assign To View radio button, then click the Assign button. All free nodes in the structure are assigned this support after getting the confirmation.

Use Cursor To Assign: To assign a support to nodes using the cursor, first select the support from the Supports dialog box. The selected support is highlighted. Select the Use Cursor To Assign radio button, then click the Assign button. The button will appear depressed and label will change to Assigning.

Make sure that the Nodes Cursor is selected so that we can select the nodes. Using the cursor, click on the nodes to which this support is to be assigned. Click on the Assign button again to finish.

Assign To Edit List: To assign a support using a typed list of node numbers, first select the support from the Supports dialog box. The selected support is highlighted. Select the Assign To Edit List radio button, then type the list of node numbers and click the Assign button.

Member Property December 23, 2013 in STAAD Pro | This allows the user to provide the cross sectional properties of members with or without the material specification. The same options can be gained access from the General | Property page. The Member Property menu option is used to create the property tag and then assign the specified property tag to select members through the Property Page. Alternatively, we may first select members and then define the member property to be assigned to these members.

The Member Property menu offers several sub-menu options as shown below:

Prismatic: This allows the user to assign Circular, Rectangular, Tee, Trapezoidal, General, etc. Cross sections to the frame members.

When we select the Prismatic option, the Property dialog box appears as shown below. Also note that the Properties dialog box also opens simultaneously letting us utilize some of the other operations available from that dialog box.

Material: Check this box and select the material from the drop down list if the new member property tag should include the materials constants.

Circle: To define a circular section, click on the Circle tab as shown in the previous figure. Enter the section diameter YD and select teh material.

Rectangle: To define the rectangle section, Click on the Rectangle tab. Enter the height YD and width ZD of the section and select the material.

Tee: To define a tee section, click on the tee tab. Enter the height YD, width ZD stem height YB and stem width ZB and select the material.

Trapezoidal: To define a trapezoidal section, click on the Trapezoidal tab. Enter the height YD, top width ZD, bottom width ZB and select the material.

Tapered Tube: This allows the user to specify a I-section having a varying depth over the length of the member by using 7 parameters as shown below:

Member Offset December 23, 2013 in STAAD Pro | The beams and columns of structure are characterized by lines in the computer model. In the actual structure, a beam spans distance which in the clear span between the faces of columns.

But in the computer model, the line for the beam spans among the centerlines of the column.

The half depth portion of either column is significantly stiffer than the beam itself from the stand point of bending. To take benefit of this extra stiffness, we may affirm that the start and end faces of the beam are offset from the node by a distance identical to the half-columndepths.

Member offsets can be specified in other situations too. Examples are  

When a bracing member does not meet the node which is defined in its incidence list.

A girder and top slab in the bridge where the centerline of the girder is several inches below the centerline of the slab.

This facility becomes very useful when the user wants to have the structural parameters of a member viz. shear force, bending moment by considering the clear distance of the member between the supports. This facility can accessed from the General | Specification also. When you select the offset menu option in the command menu, the Member Specification dialog box appears as shown below.

Location: Location defines the offset end of the member. Start is the starting point of the member and End is the Ending point of the member. Start and End depends on the Member Incidence of the member. Selecting one of these options defines the member offset to be at the start point or at the end point of the member.

Direction: Choose the Local for assigning the offsets in the local axis system. Otherwise, choose the global axis system.

Offsets: Type the offset distance from the joint in the three global directions. Click the Add button to add this specification to the structure or click Assign to assign the specification to selected member as well as add this specification to the structure.

Loading – 1 December 23, 2013 in STAAD Pro | In STAAD.Pro V8i, loads in a structure can be detailed as Dead load, Live load, Wind load, Snow load, Seismic load, temperature load and fixed-end member load. STAAD.Pro V8i can also calculate the selfweight of the structure and make it as uniformly distributed loads (UDL) in analysis. Self-weight of the members can be applied in any desired direction.

Click Commands→ Loading→ Primary Loading.

Now the Create New Definitions / Load Cases / Load Items dialog box appears. Now you have to define the loads, then click Add button.

Dead Load or Self-weight: Self-weight of all active members of the structure are calculated and applied as a uniformly distributed load. Please note that the property of the member must be defined before this command used.

 

Direction- Specify the direction in the self-weight load is to be applied by clicking on the X, Y or Z buttons.

Factor- Specify the factor with which the calculated self-weight are to be multiplied. A negative value indicates that the load is applies along the negative direction of the selected axis.

Nodal Load: Nodal loads is the combination of forces and moments, it may be applied to any free node of a structure. These loads act in the global coordinate system of the structure. Two options are available under Nodal Load: Node and Support Displacement. Positive value forces acts in the positive coordinate directions of the axis.

Member Load: The Member Load tab allows the user to apply loads on the span of frame members.

Concentrated Load: To specify a concentrated force or moment, click the Concentrated Force or Concentrated Moment tab. The data items are explained below.

Linear Varying Load: The load is applied over the entire length of the member, varies with respect to the distance.

Loading – 2 December 24, 2013 in STAAD Pro Area Load: This allows the user to apply load over area, which will be distributed on surrounding beams based on the one way distribution. This load is a one-way distributed pressure load on members that circumstances a panel. Enter the value of area load in current units. This load always acts along the positive local y direction on the two longest member on each panel.

Note: Area load should not specified on members declared as Member Cable, Member Truss or Member Tension.

Floor Load: User can apply the load over the panel, which will be distributed on surrounding beams based on a two-way distribution. This load is two-way distributed pressure load on members that circumscribe a panel. The data items are explained below: Load – Floor load value in the current units. This load will act parallel to the global vertical axis.

Direction – The floor may be considered as acting perpendicular to plane of the panel on which it is defined. This is normal load static condition.

Range – Define X Range/ Y Range/ Z Range. Specify the location of the floor using the Define X Range option. The load will be calculated for all members lying between this range.

One Way Distribution – Check the box for one way distribution to get a one way type distribution of the pressure. In such cases, the program find out the shorter side of the panel. It then divides the load in between the long direction beams. No load is generated by this option if the panel is square in shape.

Plate Load: The Plate Load tab allows the user to apply elements loads. The Plate Load tab offers several sub-menu options as shown below.

Pressure On Full Plate:

Load – W1 is the variable using which the pressure value is defined, in pressure units.

Direction – The load may be applied along the local Z – axis, or along one of the global X, Y or Z – axis (GX, GY, GZ) Concentrated Load:

Use this option to define a concentrated load that acts on specific point within the boundary of the element. If a load acts at a node point of an element, it is advisable to apply it using the Nodal Load option described in earlier pages.

Load – The magnitude of load is specified in the box alongside Force. X and Y define the location of the load, in terms of the distance from the origin of local X and Y axes of the element.

Direction – The load may be applied along the local Z-axis, or along one of the global X, Y or Z – axis (GX, GY, GZ).

Partial Plate Pressure:

To Specify a uniform pressure on the entire element or a non user specified portion of the element, use this facility. The data items are explained below: Load – The element pressure (force per unit area) or Concentrated load (force unit). For concentrated load the values of X2 and Y2 must be omitted, while X1 and Y1 must be specified.

X1, Y1, X2, Y2 – For element pressure (force per unit area), these values represent the coordinates of the rectangular bpundary on which the pressure is applied. If X1, Y1, X2 and Y2 are all zero; the pressure is applied over the entire element. If X1 and Y1 are specified but X2 and Y2 are omitted, then W1 is treated as concentrated load.

Direction – GX, GY, GZ represent the global X, Y and Z direction along which the pressure may be applied Local Z indicates that the pressure is applied normal to the element in the local Z direction.

Trapezoidal: To specify a trapezoidal varying pressure load on a plate, select the Trapezoidal tab. The load is applied over the entire element in the local Z direction, varying along the positive local X or Y direction. The data items are explained below.

Direction of Pressure – GX, GY and GZ represent the global X, Y and Z direction along which the pressure may be applied. Local Z indicates that the pressure is applied normal to the element in the local Z direction. Enter the pressure intensity F1 at the lowest local coordinate location (start) and the intensity F2 at the highest local coordinate location (end), Start and End are defined basd on the positive direction of the local X-axis or local Y-axis.

Variation along element – Define the direction in which the pressure varies as either the local X ot Y direction or Choose the joint option, which is discussed next.

Joint – Check the joint option to apply different value of pressure at different nodes of the plate element. When checked, the dialog box will change as shown below. Apply different values of pressure in the edit boxes for the different nodes.

Hydrostatic: To model loads due to hydrostatic pressure on one or more adjacent elements, select the Hydrostatic tab. The hydorstatic load is converted to Trapezoidal loads on the elements. The load is applied over the entire area of the element. The data items are explained below:

Force – Enter the value of the load at the minimum and maximum global axis in current units.

For example, to model a retaining wall with soil pressure, W1 is the force at the bottom of the wall and W2 is the force at the top of the wall.

Interpolate along Global Axis – Specify the global axis (X, Y or Z) along which the load vary from W1 to W2. For example, the load would vary along the Y – axis on a vertical retaining wall.

Select Plate(s) – Unlike the load definition options, we must select plate(s) for this option to became active. Click on this button to select plate(s). Click on the Select Plates button. A dialog box will appear. Select all the plates of a wall on which we wish to apply hydrostatic load. Click on Done. The hydrostatic dialog box will re-appear.

Direction of pressure – Specify the direction of design pressure as Local Z axis or global axes (GX, GY or GZ) and click on Add. This will assign a linearly varying hydrostatic load on all the selected elements.

Element Joint Load: To specify a varying pressure at each joint on a plate, select the Element Joint Load option. The data items are explained below.

Joint Load Data – Choose Three Noded Facet / Four Noded Facet depending on whether the plate element is 3 noded 4 noded.

Direction – The load may be applied along the local Z – axis or along one of the global X, Y or Z – axis (GX, GY, GZ) Add – After defining a load, click the Add button to add this under current load case in the Loads dialog box.

Wind Load Generation December 25, 2013 in STAAD Pro | The wind load generation is a utility, which takes place as an input wind pressure and height ranges over which these pressures act and generates nodal point and member loads.

This facility is available for two types of structures: 1. Panel type or closed structures.

2. Open structures.

Closest structures are ones like where non-structural entities like glass facade, aluminium sheets, timber panels or non-load bearing walls act as an obstruction to the wind. If these entities are n and ot included in the structural mode, the load generated because of wind blowing against them needs to be computed. Therefore, the steps involved in load generation for such structure are 1. Identify the panels – regions circumscribed by members so that a polygonal closed area is formed. The area may also be formed between the ground level along one edge and members along other.

2. Calculate the panel area and multiple it by wind pressure.

3. Convert the resulting force into nodal point loads.

Plates and solids are not considered in the calculation of the panel area. Openings within the panels may be modelled with the help of exposure factors. An exposure factors is associated with each joint of the panel can be reduced or increased.

Open structures are those like transmission towers, in which the region between members is “Open� allowing the wind to blow through it. The procedure for load generation for open structures is 1. Calculate the exposed area of the individual members of the model.

2. Multiply that exposed area by the wind pressure to arrive at the force and apply the force on the individual members as a uniformly distributed load. It is assumed that all members of the structures within the specified Rangers are subjected to the pressure and hence, they will all receive the load. The concept of members on the Windward side shielding the members in the inside regions of their structures does not exist for open structures.

At a large structure may consist of hundreds of panel and members, the user with the help of this facility can avoid a considerable amount of work in calculating the loads.

The wind load menu option allows the user to define the parameters for automatic generation of wind loads on the structure.

STAAD.Pro V8i is now capable of generating the wind pressure profile for a structure in accordance with the ASCE-7-95 as well as the ASCE-7-02 codes. The pressure profile is the table of values of wind intensity versus height above ground.

The calculated pressure may then be applied on the structure to compute loads on the member using the in-built program’s wind load generation algorithm for the closed as well as open-lattice type structures.

When the wind load B&B of my menu option is selected, the new wind type dialog box appears, as shown below.

Enter the ‘Type No.’ which denotes the number by which the wind load type will be identified.

Multiple wind types can be created in the same model. Click on the Add button within this dialogue box and then click on close.

The newly created TYPE 1 wind definition will appear underneath wind in the Load dialogue.

Select the TYPE 1 name in the tree control and click on the Add button. The dialogue box shown below will prompt for the pressure profile for this wind definition.

As we said earlier, the pressure profile is the table of wind intensity versus height above ground.

If we know that, that information can be typed into the box above.

To calculate the wind intensity, use the following formula from IS 875-Part 3.

Vz = Vb k1 k2 k3 and pz = 0.6 Vz2 where, Vz = Design wind speed at any height Vb = Base wind speed. k1 = probability factor. k = terrain, height and structure size factor. k3 and = topography factor.

pz = design wind pressure.

Exposure: The exposure tab is used to modify the influence area of wind load associated with particular joints in the structure. By default, the exposure factor is 1.0, thus the wind force is applied on the full influence area associated the joints. Click on Add to add this load under the current load case in the load dialogue box.

Assigning Wind Load December 25, 2013 in STAAD Pro This tab allows the user to apply previously created wind load type on the structures through the means of a load case.If the model already contains previously defined wind load cases, a dialogue box resembling the one shown will appear.

Select type: Choose a previously defined wind load type from the drop down list.

Direction: Specify the global direction in which the wind load is to be generated by clicking the X, Z, -X or –Z radio button. When wind is generated in X direction, the wind load is applied on the near side and when –X is chosen the load is applied on the far side. Generation in Z or –Z also works the same way.

Factor: Specify the factor to multiply the calculated wind loads.

Open structure: By default, the load generation is based on the assumption that the region between members is covered by panels. To generate loads on open structures like highway signs or transmission towers, switch on this box. The members are selected and X is used and the factor is positive, then the exposed surface facing in the –X direction will be loaded in the positive X direction. If X and a negative factor, then the exposed surface facing in the X direction will be loaded in the negative x direction. If –X is entered and a positive factor, then the exposed surfaces facing in the +X direction will be loaded the positive X direction.

Analysis December 26, 2013 in STAAD Pro | STAAD.Pro V8i offers STAAD engine for general purposes structural analysis and design. The modelling mode of STAAD environment is used to prepare structural input data. After the analysis is performed, used the menu option File→ View→ Output File→ STAAD Output to view the output files.

The STAAD Analysis engine perform analysis and design simultaneously. However, to carry out the design, the design parameters too must be specified along with the geometry, properties, etc.

Before you perform the analysis. Also, note that you can change the design code to be followed for design and the code check before performing the analysis/design.

Perform analysis: To do the analysis must be need to add the command from Commands→ Analysis→ Perform analysis…

This allowed the user to specify the instructions for the type of analysis to be performed using STAAD engine. In addition, this command may be used to print various analysis-related data such as load information, statics check information, mode shapes etc.

The analysis menu offers several sub menu options. When you select one of the analysis commands, you may specify the analysis-related data to be printed in the STAAD output (.ANL) file by selecting the print option radio buttons, explained below: Load data: print all the load data.

Statics check: provides summation of the applied load and support reaction as well as summation of moment of load and reactions taken around the origin.

Statics load: print everything that statics check does and summation of all internal and external forces at each joint.

Mode shapes: print mode shapes values at the joints or are calculated mode shapes.

Both: this option is equivalent to the load data plus statics check option.

All: this option is equivalent to load data plus statics data.

Run Analysis: The Analysis is performed under the commands under the analyse menu in the Modelling Mode.

Select the Run Analysis option to perform Analysis/Design.

The Analysis Status dialog box appears:

This dialog box displays the status of the analysis process. If an error occurs during the analysis, the above dialog box displays the error message.

View Output File: it will invoke the STAAD viewer with the analysis results presented in a textual format.

Go to Post Processing Mode: it will take you to the STAAD.Pro Post processor where you can graphically.

Stay in Modelling Mode: it will keep you in Modelling environment.

During the analysis, an output file is generated. This file may contain selected input data items, results and error messages. To include a report of the input data items in the output file, use the menu options under Commands | Pre Analysis Print. The generated output file may be viewed using the menu option File | View | Output File | STAAD Output.

Any errors that occur during the analysis process may be viewed using the menu option File→ View→ Output File.

Concrete Design December 26, 2013 in STAAD Pro | STAAD has the capabilities of performing concrete design on limit state method of IS 456 (2000).

Beam Design: Beams are designed for flexure, shear and torsion. If required the effect the axial force may be considered. For all these forces, all active beam loadings are pre-scanned to identify the critical load cases at different section of the beams.

Column Design: Columns are designed for axial forces and biaxial moments at the ends. All active load cases are tested to calculate reinforcement. The loading which yield maximum reinforcement is called the critical load. Column design is done for square, rectangular and circular sections. By default, square and rectangular column and designed with reinforcement distributed on each side equally for the sections under uni-axial moment.

Design Parameters: The program contains several parameters which are needed to perform design as per IS 456 (2000). Default parameter values have been selected that they are frequently used numbers for conventional design parameters. These values may be changes to suit the particular design performed.

Performing Concrete Design: 1. Click Commands→ Design→ Concrete Design.

2. Now the user can specify the design parameters for the structure.

3. Concrete Design dialog box appears.

4. Click the Select Parameters button. Now you can select the desired parameters for the concrete design.

5. Click Ok. Then Click Define Parameters button, now you can define the parameter

Important Parameters To Be defined Are Given Below: Parameter Name

Default Value

Description

FC

25000 KN/mm2

Concrete yield strength.

FYMAIN

415000 KN/mm2

Yield stress for main reinforcing steel.

FYSEC

415000 KN/mm2

Yield stress for secondary reinforcing steel.

MAXMAIN

60 mm

Maximum main reinforcement bar size.

MAXSEC

12 mm

Maximum secondary reinforcement bar size.

MINMAIN

10mm

Minimum main reinforcement bar size.

MINSEC

8 mm

Minimum secondary reinforcement bar size.

6. Now Click Commands button, Design Commands dialog box appears.

7. Click Add button to add the parameters, then assign the commands to the respective members.

8. Assign the DESIGN BEAM to the members parallel to X and Z direction.  

Click Select→ Beam Parallel To X. Click Select→ Beam Parallel To Z.

9. Assign the DESIGN COLUMN to the members parallel to Y direction. 

Click Select→ Beam Parallel To Y.

10. Then Run Analysis, the result provide the suitable concrete design for the structure.

NOTE: After the analysis,double – click the member of the structure, it show the concrete design, if the concrete design of the element is missing, then it is said to unsafe.

Time History Analysis December 26, 2013 in STAAD Pro | Time history analysis is an advanced method of dynamic analysis. It has an ability to incorporate harmonic forcing functions that can be described by sinusoidal curves with a specified arrival time, frequency, amplitude and duration.

Define Time History Dialog: Used to define the Forcing Function of a time varying load.

Click Commands→ Loading→ Definitions→ Time History→ Forcing Functions is selected or The Add… button is clicked in the Load & Definition dialog found on the General | Load & Definition page.

Integration Time Step: Solution time step used in the step-by-step integration of the uncoupled equations.

Type: This refers to the number of the type of functions.

Loading type: Select the Acceleration, Force or Moment option to define the type of functions being input.

Save: Select this option to create an external file containing the history of displacements of every node of the structure at every time step.

Function Options: Define Time VS <loading type>

Used to specify a time history forcing function, where the loading type is that selected above.

Specify the values Time and corresponding Force or Acceleration. The time history function is plotted on the bottom of the dialog as data pairs are entered.

Harmonic:

Curve Shape: Specify if the harmonic function is a SINE or COSINE curve.

Frequency or RPM: Choose Frequency and enter circular frequency in cycles per second or RPM and enter revolutions per minute.

Amplitude: Max. Amplitude forcing function in current units.

Phase: Phase angle in degrees.

Cycles:

No.of cycles of loading.

Step of Sub Div: Choose the step option to time step of loading SubDiv to sub divide a 1/4 cycle into this many integer time steps.

Spectrum: Select this Function Option to provide spectrum parameters for your time history loading.

Time History Parameters Dialog:

Time Step: Specify a solution time step to be used in the step-by-step integration of the uncoupled equations.

Damping: The following options are available for specifying damping: Damping-this is to be used for specifying a single model damping ratio which will be applied to all mode. The default value is 0.05.

CDAMP â&#x20AC;&#x201C; if a damping ratio has already been specified under CONSTANTS based on the type of material in the structure, the value may be used directly in time history analysis. Check this option for that purpose.

MDAMP â&#x20AC;&#x201C; we wish to utilise individual damping ratios for individual modes, that is achieved through the means of the MDAMP option. The first step to doing this is the specification of those individual damping ratios, as explained under section 5.26 .3 of the STAAD technical reference manual and is done graphically from the command-define damping menu. If this first step has been completed, the instruction to utilise MDAMP done by selecting this option shown above.

Arrival time: specify values of possible arrival times of the various dynamic load types. The arrival time is the time at which the load type begins to act at a joint or at the base of the structure. The same load may have different arrival times for different joint and hence all these values must be specified here. The arrival time and time force pairs for the load types are used to create the load vector needed for each time step of the analysis.

Introduction to FEM The Finite Element Method (FEM) is a numerical technique for finding approximate solution of partial differentially equation (PDE) as well as integral equation.The finite element method is a good choice for solving partial differential equations more complicated the domains, when the domains changes, when the desired precision varies over the entire domains, or when the solution lacks smoothness.

The final element method originated from the need for solving complex elasticity and structural analysis in civil and aeronautical engineering. Its development can be traced back to the work by Alexander Hrennikoff and Richard Courant. While the approaches used by the pioneers are dramatically different, they share one essential characteristic: mesh discretization of continuous domains into a set of the sub-domains, usually called elements.The development of final element that began in the earnest in the middle to late 1950s for airframe and structural analysis and gathered momentum at the University of stuttgart through the work of Jhon Argyris and at Berkeley through the work of Ray W. Clough in the 1960s for use in civil engineering. By late 1950s, the key concept of stiffness matrix and element software NASTRAN in 1965. The method was provided with rigourous mathematical foundation in 1970 with the publication of strang and Fixâ&#x20AC;&#x2122;sâ&#x20AC;&#x2122;An analysis of the finite element method has since been generalised into a branch applied mathematics for numerical modelling of physical system in a wide variety of engineering disciplines.

Plate December 27, 2013 in STAAD Pro Add Plate: This option allows you to Triangular or Quadrilateral plate elements by connecting existing nodes. To add quadrilateral plate, select Quad from the sub-menu. For triangular plates, select Triangle from the sub-menu . The cursor changes to Quad plate or Triangular Plate shapes. To create new elements, simply click on the existing nodes in the right sequence. A rubber banded area shows the boundary of the plate being generated.

Set New Plate Attribute: Similar to the “ Set New Member Attribute” command in which the user is in can define the property, material and releases to each new plate element as it is created, has been introduced.

In order to define the attributes for plate element before they are created, go to Geometry→ Add Plate → Set New Plate Attributes from the main menu.

A dialogue box will prompt for various attributes of the plate to be pre-defined. A summary of a specific attributes are defined in the table below.

Button

Function

Create New Property

Prompts the plate thickness dialogue box that the thickness of the plate at each of the common node can be defined.

Create New Material

Defined the various material properties of the plate including poison ratio, modulus of elasticity, shear modulus, etc.

Create New Release

Define the degree of freedom to be released at each node of the plate to the plane stress no in plane rotation or no stiffness.

Multiple properties, releases and materials can be created and saved for future use. To choose from various pre-defined types, simply select the appropriate definition using the “Select Property”, “Select Material” or the “Plate Release” drop-down boxes.

For the program to recognize the pre-defined attributes, the “Assign these attributes while creating a new plates” check box must be checked. Any new plate element created from here on will now possess these attributes.

How to Sketch Plates: 1. Click the plate icon

.

2. Now automatically beam cursor will change into plate cursor and nodes in the structure are visible.

3. Plate can drawn only clicking the four node points.

4. After placing the plate, click Commands menuâ&#x2020;&#x2019; Member Propertyâ&#x2020;&#x2019; Plate Thickness.

Now the Properties Whole Structure dialog box appears.

5. Click Thickness button, now the Plate Element/ Surface Property dialog box appears, where you add different types of member properties of plate and surface element.

6. Type respective value of thickness for the plate element. Click Add button.

7. Now click Select menuâ&#x2020;&#x2019; Plate cursor.

8. Now select the plates and select the radio button Assign to selected plates and click Assign button.

9. Now open the 3D rendering page. You can see the Plate with defined thickness.

Surface December 27, 2013 in STAAD Pro | Add Surface: Adding surface is similar to the adding plates where the plates can be placed by clicking only 4 node points while the surface can be placed by clicking more than 4 node points. Finally you have to click the node point where you start placing the surface.

How to Add surface in the structure: 1. Click Add Surface icon or Click Geometry menuâ&#x2020;&#x2019; Add Surface.

2. Now the beam cursor changes into surface cursor.

3. Place the surface by clicking the node points and finally click the node point where begin.

4. As usual define the property for surface. Type the respective thickness value for surface member.

5. Now Assign the member property to the surface by selecting the surfaces using the surface cursor.

6. Now Open 3d Rendering View.

Meshing December 28, 2013 in STAAD Pro | Meshing is the process of creating a finite element mesh over the respective member. The nodes that form the corners of the polygon representing the super â&#x20AC;&#x201C; element must already exit on the drawing before the facility can be availed. They can be selected in a sequence and the process launched.

Meshing can be done over the plate and surface they can be classified into two are 1. Plate mesh.

2. Surface mesh.

Plate Meshing: This is an utility meant for taking an existing plate element and subdividing into a set of smaller elements. Consequently, a plate element must already exist on the drawing in order for this facility to be enabled. Using the Plate Cursor, Click the right mouse button on the element and select Generate Mesh. Alternatively select the Geometry menuâ&#x2020;&#x2019; Generate Plate Mesh.

If the element being meshed is triangular, the polygonal mesh feature described in the previous section will automatically become activated. If the element is quadrilateral, the user have to choose between polygonal and quadrilateral meshing.

1. Select the plate element, right click in the selected element.

2. Click Generate Plate Meshing. Now the Meshing type dialog box appears.

3. Choose the type of meshing, Click Polygonal Meshing and click OK

4. Now the Define Mesh Region dialog box appears, user have to define the boundary of the meshing surface. Click OK button.

5. Now the meshing surface is visible, then apply the plate load and proceed analysis. ď&#x201A;ˇ

Polygonal Meshing.

ď&#x201A;ˇ

Quadrilateral Meshing.

Surface Meshing: Surface meshing is similar to the process of plate meshing. Same procedure is followed for the surface meshing. Click Geometry menu→ Generate Plate Mesh. Now select the surface element and provide respective boundary condition. Click OK button. Now you get the surface mesh.

Slab Design December 28, 2013 in STAAD Pro | Slabs are the important structural component where the pre-stressing is applied. With increase in the demand for fast track, economical and efficient construction, pre-stressed slabs are becoming popular. The slabs are presented in two groups are  

One way slabs Two way slabs

A slab is pre-stressed for the following benefits. 1. Increased span-to-depth ratio Typical values of span-to-depth ratios in slabs are given below.  

Non-pre-stressed slab 28:1 Prestressed slab 45:1

2. Reduction in self weight. 3. Section remains uncracked under service loads which increases durability. 4. Quick release of formwork which help for fast construction. 5. Reduction in fabrication of reinforcement. 6. More flexibility in accommodating late design changes.

The structure for this project is a slab fixed along two edges. We will model it using 6 quadrilateral (4-noded) plate elements. The structure and the mathematical model are shown in the figures below. It is subjected to self-weight, pressure loads and temperature loads. Our goal is to create the model, assign all required input, perform the analysis, and go through the results

Design of One â&#x20AC;&#x201C; Way Slab December 28, 2013 in STAAD Pro One â&#x20AC;&#x201C; Way Slab: Rectangular slabs can be divided into two groups based on the support condition and length-tobreadth ratios. The one-way are identified as follows: 1. When a rectangular slab is supported on all the four edges and length-to-breadth (L/B) ratio equal to or greater than two, the slab is considered to be a one-way-slab. The slab spans predominantly in the direction parallel to the shorter edge.

2. when a rectangular slab is supported only on two opposite edges, it is a one-way slab spanning in the direction perpendicular to the edges. Precast planks fall in this group.

A slab in a framed building can be a one-way slab depending upon its length-to-breadth ratio. A one-way is designed for spanning direction only. For the transverse direction, a minimum

amount of reinforcement is provided. A slab under flexural behavior like a beam. One-way slabs are analysed and designed for spanning direction similar to the rectangular beams. A slab of uniform thickness subjected to a bending moment uniformly distributed over its width. Although a one meter wide strip of the slab is considered as a beam for the analysis and design for flexural strength, there is a difference between the beam and slab as follows.

When a beam bends, the portion of the section above the neutral axis is under compression and hence subjected to a lateral condition. Hence after bending, the cross-section, will strictly not be a rectangular, but nearly a trapezoidal.

In the case of a one-way slab, for a design strip, such lateral displacements and strains are prevented by the remainder of the slab on either side i.e it retains the rectangular shape after even after bending. The final design involves the checking of the stresses in concrete at transfer and under service loads with respect to the allowable stresses. The allowable stresses depend on the type of slab. During the design, the reinforced bars are usually spaced uniformly over the width of the slab.

Design Steps In STAAD.Pro V8i: 1. Create a member to represent the slab.

2. Assign the suitable support to both ends.

3. Assign the Cross section properties.

4. Assign the load as follows 

Dead Load.

1. Selfweight 2. Uniformly Distributed Load to represent the floor finish 

Live Load

1. Uniform Distributed Load 

Combination Load as per IS 456.

Design Of Two – Way Slab December 28, 2013 in STAAD Pro |

If a concrete slab is supported by a beams along all four edges and reinforced with steel bars arranged perpendicularly, it is known as two-way slab. In other words, slab panels that deform with significant curvature in two orthogonal directions must be designed as two-way slabs, with the principle reinforcement placed in the two directions.

In general, twisting moments develop in addition to bending moments in a two-way slab element, except when the element is oriented along the principal curvatures. These twisting moments can become significant at points along the slab diagonals Wall Supported VS Beam Supported Slabs: The distributed load on the typical tw0-way slab is transmitted partly along the short to the long edge supports and partly along the long span to the short span supports. In wall-supported panels, these portions of the load are transmitted by the respective wall supports directly to their foundations vertically below. The design considerations of deflection control criteria.

In beam-supported panels, the portion of the load transmitted by the slab in any one direction is in turn transmitted by the beam in the perpendicular direction to the two supporting columns.

Slabs supported by beams behave differently, when compared to slabs supported on walls, because of the influence of the following factors.   

Deflections in the supporting beams.

Torsion in the supporting beams.

Displacements in the supporting beams.

Design Steps in STAAD.Pro: 1. Create the frame model of the structure.

2. Use the Parametric Modelling to find the optimisation size of the elements.

3. Assign the supports.

4. Assign the Primary and Combination Loads.

5. Do the analysis and design.

Design Of Staircase December 28, 2013 in STAAD Pro | Staircase is a vital element of a building providing entree to different floors and roof of the building. It comprises of a flight of steps and one or more midway landing slabs in the middle of the floor levels. Architectural thoughts including aesthetics, structural feasibility and functional

desires are major characteristics to select a specific type of the staircase. Other persuading parameters for the selection of lighting, ventilation, comfort, accessibility, space etc.

The common terminologies used in staircase are: ď&#x201A;ˇ

ď&#x201A;ˇ

ď&#x201A;ˇ

Tread: The horizontal top portion of a step where foot rests is called as tread. The dimension varies from 270 mm for residential buildings and factories to 300 mm for public buildings where large number of persons use the staircase.

Riser: The vertical distance between two successive steps is called as riser.

The dimension of the riser varies from 150 mm for public buildings to 190 mm for residential buildings and factories.

Waist: The thickness of the waist-slab on which steps are made is called as waist. The thickness of the waist is the minimum thickness perpendicular to the soffit of the staircase. The steps of the staircase resting on waist-slab can be made of bricks or concrete.

Design Procedure In STAAD.Pro: Design the waist-slab type of the staircase     

Finish Load = 1Kn/m2 Live Load = 5Kn/m2 Riser = 160mm Tread = 270mm Use M25 grade concrete and Fe 415 steel.

Calculate Natural Frequency of a Building

By Response Spectrum Analysis January 1, 2014 in STAAD Pro | Design Procedure For Response Spectrum Analysis: 1. Open STAAD.Pro V8i.

2. Click New Project and set the units as Kilo Newton & Meter.

3. In STAAD.Pro, open Run structure wizard in Geometry menuâ&#x2020;&#x2019; Run Structure Wizard.

4. Change the Model Type into Frame Model and select Bay Frame, now the Select Parameter dialog appears.

5.Set the parameter of the structure as shown below.

6. Click File menuâ&#x2020;&#x2019; Merge Model with STAAD.Pro Model and place the model at origin.

7. Now assign Fixed support to the structure.

8. Assign the Member Property for column as YD=0.6 m & ZD= 0.6 m and for beam YD= 0.75 m & ZD= 0.6 m.

9. Now you can see the model in 3D Rendering.

10. Next Loading process, Click Commandsâ&#x2020;&#x2019; Loadingâ&#x2020;&#x2019; Definitions.

11. Select Seismic Definitions and click Add button.

12. Now Add New : Seismic Definitions dialog box appears, in Type drop down box select the respective codes for design. i.e IS 1893 – 2002/2005 13. Click Generate button, now the IS 1893 Seismic Parameter dialog box appears.     

Choose the zone and it factors, Response Reduction factor, Importance Factor, Type of Structure and Type of soil.

14. Click Generate button. In IS 1893 Seismic Parameter dialog box type the Damping Value as 0.05. Click Add button.

15. Now your seismic definition is added, then add other factor of seismic definition. First you have to add the basic factors.  

Self Weight Factor = 1, click Add button.

Floor Weights must assigned as given below and click Add button.

16. Now you are going to add the Load Case Details.

17. Load Case Type 1 ( Here you assign floor loads only in GY direction and values must be negative.)    

LOAD CASE 1 YRANGE 0 42 FLOAD 3.5 YRANGE 43 45 FLOAD 2.5 YRANGE 0 45 FLOAD 1.5

18. Load Case Type 2 Response Spectrum (Here you add the self weight of the structure in positive X and Z direction and negative Y direction. Different floor load in all three global directions.)    

LOAD CASE 2 SELFWEIGHT X 1 LIST ALL SELFWEIGHT Y -1 LIST ALL SELFWEIGHT Z 1 LIST ALL

         

FLOOR LOAD YRANGE 0 42 FLOAD 3.5 GX YRANGE 0 42 FLOAD 3.5 GY YRANGE 0 42 FLOAD 3.5 GZ YRANGE 43 45 FLOAD 3.5 GX YRANGE 43 45 FLOAD 3.5 GY YRANGE 43 45 FLOAD 3.5 GZ YRANGE 0 45 FLOAD 3.5 GX YRANGE 0 45 FLOAD 3.5 GX YRANGE 0 45 FLOAD 3.5 GX

19. Now you have to assign the self weight to structure by Assign to view.

20. Then add another load item Response Spectra as shown below.

21. Then Click Commands→ Miscellaneous→ Cut Off Mode Shape…. Mode Shapes Value is 10.

22. Click Commands→ Analysis→ Perform Analysis Print All. 23. Then Run Analysis or press CTRL + F5.

24. Result Values Eigen Values: Calculated frequencies for load case.

Mode Shape Values:

Mass Participation Factor is important for analysis.

25. Deflection:

26. Click Ok button.

How To Calculate Natural Frequency By Rayleigh Method December 31, 2013 in STAAD Pro | Design Procedure For Rayleigh Method: 1. Open STAAD.Pro V8i.

2. Click New Project and set the units as Kilo Newton & Meter.

3. In STAAD.Pro, open Run structure wizard in Geometry menuâ&#x2020;&#x2019; Run Structure Wizard.

4. Change the Model Type into Frame Model and select Bay Frame, now the Select Parameter dialog appears.

5.Set the parameter of the structure as shown below.

6. Click File menuâ&#x2020;&#x2019; Merge Model with STAAD.Pro Model and place the model at origin.

7. Now assign Fixed support to the structure.

8. Assign the Member Property for column as YD=0.6 m & ZD= 0.6 m and for beam YD= 0.75 m & ZD= 0.6 m, Plate Thicness = 0.15m.

9. Now you can see the model in 3D Rendering.

10. Next Loading process, Click Commandsâ&#x2020;&#x2019; Loading.

11. Now the Load & Definitions dialog box opens, add the following loads:

12. Then Perform Analysis, Select All. 13. Now Run Analysis. Result you will get the Rayleigh Frequency for load case 1.

Note: Please ignore if you get any warnings.

14. Now add Load case 2: Assign the following loads

15. Again Run Analysis. Now you get the Rayleigh Frequency for load case 1 and load case 2.

16. Then check the deflection using Animation command. Provide suitable concrete design the control the deflection.

How To Calculate Natural Frequency of a Building By Modal Shape December 31, 2013 in STAAD Pro | Tags: staad pro seismic design tutorials Design Procedure For Modal Shape: 1. Open STAAD.Pro V8i.

2. Click New Project and set the units as Kilo Newton & Meter.

3. In STAAD.Pro, open Run structure wizard in Geometry menuâ&#x2020;&#x2019; Run Structure Wizard.

4. Change the Model Type into Frame Model and select Bay Frame, now the Select Parameter dialog appears.

5.Set the parameter of the structure as shown below.

6. Click File menuâ&#x2020;&#x2019; Merge Model with STAAD.Pro Model and place the model at origin.

7. Now assign Fixed support to the structure.

8. Assign the Member Property for column as YD=0.6 m & ZD= 0.6 m and for beam YD= 0.75 m & ZD= 0.6 m, Plate Thicness = 0.15m.

9. Now you can see the model in 3D Rendering.

10. Click Commandsâ&#x2020;&#x2019; Miscellaneousâ&#x2020;&#x2019; Cut Off Mode Shape...

11. Now the Cut Off Mode Shape dialog box appears. Enter the desired number of modes you want. Click Ok

12. Then add the following Load Cases:

13. Finally you have add the Modal Calculation command.

14. Now assign the respective loads to the elements.

15. Then Perform Analysis and Run Analysis.

16. In Result you get the Calculated Frequency of Load Case.

17. According to IS 1893, Mass Participation Factors must be atleast greater than 90.

18. Then Check the deflection using Animation command.

19. Now you have to provide the suitable concrete design to control the deflection.

Note: For more info and further details watch the video.

Wind Load Intensity Calculation December 31, 2013 in STAAD Pro | Tags: Staad pro wind load intensity calculation

How to calculate wind load as per ASCE â&#x20AC;&#x201C; 7 ?

Design Procedure To Calculate Wind Load Intensity: 1. Open STAAD.Pro V8i.

2. Click New Project and set the units as Kilo Newton & Meter.

3. Open the Grid and Form the following grid.

4. By using the Snap/Node Beam Add the members and select the members.

5. Now use the Translational Repeat option to build the structure.

6. Assign the respective support for the structure.

7. Assign the suitable member property for the model.

For Column = 0.75 x 0.75 m For Beam: YD = 0.60; ZD = 0.40 8. Now open the structure in 3D rendering.

9. Then Wind Definition in Load Case.

10. Now click Calculate as per ASCE-7 button. Now the select respective code and type of building. Click OK

11. Wind load in calculated according the varying height of the structure. Click Close button.

12. Add the suitable factor of exposure.

13. Assign the Exposure against the structure.

14. Assign the following Load Cases.

15. Perform Analysis and Run Analysis.

16. According to the result values provide the suitable concrete design for the structure.

17. Again Run the Analysis.

18. Now you get the concrete design of the elements.

19. In Post Processing, You can get the Bending Moment and Shear Force values.

AUTOMATIC SPRING SUPPORT GENERATION FOR FOOTINGS AND SLAB ON GRADE

INTRODUCTION: STAAD.Pro V8i has a facility for automatic generation of spring supports to model footings and MAT foundations.

STAAD.Pro foundation support generator STAAD.Pro has a foundation support generator with the following three options: 1. Footing 2. Elastic MAT 3. Plate MAT In this blog, only the Footing and Plate MAT options will be discussed.

Option 1: Footing Suppose a 10' tall (12" x 12") square column placed on a (8' x 8') square footing is to be modeled in the STAAD.Pro 3

environment. The footing is resting on soil with sub-grade modulus of 144 kip/ft . The engineer would like to model the soil as spring supports.

Figure 1: Physical and analytical models of a simple column on a footing.

This model can be easily created using the STAAD.Pro V8i interface. To assign the supports: 1. Click on the General -> Supports control tab on the left.

2. Click on the Create button on the right. The Create Support dialog box shown in Figure 2 will appear.

3. Select the foundation tab in the Create Support dialog box.

Figure 2: Create support dialog box.

Note that in this dialog box there are three options for generating the foundation support. In this case, the Footing option will be selected.

4. Populate the dialog box as shown in Figure 3.

Figure 3: Foundation Support Generator - Footing Option.

This footing has to be assigned to the stick model.

Calculations: Area of the footing (A) = 10' x 10' = 100 sq.ft Sub-grade Modulus (E) = 144 kip/ft3 Spring Constant (K) = (A) X (E) = 100 sq.ft X 144 kip/ft3 = 14,400 kip/ft For a column reaction load of P=10 kips, Support displacement (d) = P/K = 10 kips/14,400kip/ft X 12 in/ft = 0.008 in.

Figure 4 shows the displacement of node 3 in the STAAD.Pro model. Please note that the displacement is same as what we have calculated above.

Figure 4: Displacement at node 3.

The STAAD.Pro model is attached in Appendix A of this document.

Option 2: Plate MAT Suppose a (80' x 80') square MAT foundation is to be modeled in the STAAD.Pro environment. The MAT foundation 3

is resting on soil with a sub-grade modulus of 144 kip/ft . The engineer would like to model the soil as spring supports.

(Physical Model)

(Analytical Model) Figure 5: Physical and analytical model of a simple MAT foundation.

This model can be easily created using the STAAD.Pro V8i interface. To assign the supports: 1. Click on the General -> Supports control tab on the left.

2. Click on the Create button on the right. The Create Support dialog box shown in Figure 6 will appear.

3. Select the foundation tab in the Create Support dialog box.

4. Populate the dialog box as shown in Figure 6.

Figure 6: Foundation Support Generator - Plate MAT Option.

This support has to be assigned to the all the plates that represent the MAT foundation.

Figure 7: Foundation Support Generator - Plate MAT Option.

Figure 7 shows the influence area for node 342 which is connected to four plates (4'x 4') square plates (shown with green outlines).

Calculations: Influence Area for node 342 (A) = 4' x 4' = 16 sq.ft

Sub-grade Modulus (E) = 144 kip/ft3

Spring Constant for node 342 (K) = (A) X (E) =16 sq.ft X 144 kip/ft3 = 2304 kip/ft 2

For uniform distributed MAT load of Q=0.2 kip/ft , 2

Total force on Influence Area = Q X A = 0.2 kip/ft X 16 sq.ft = 0.32 kips Approximate Support displacement (d) = P/K = 0.32 kips/2304kip/ft X 12 in/ft = 0.017 in.

Figure 8: Displacement at node 342.

Figure 8 shows the displacement of node 342 in the STAAD.Pro model. Please note that the displacement is same as what we have calculated above. Figure 9 shows the influence area of node 342 in the STAAD.Pro output file.

Please note that the influence area of 16 sq.ft is same as what we have calculated above.

Figure 9: Influence Area of node 342.

The STAAD.Pro model is attached in Appendix B of this document.

Appendix A STAAD PLANE START JOB INFORMATION ENGINEER DATE 19-Mar-09 END JOB INFORMATION INPUT WIDTH 79 UNIT FEET KIP JOINT COORDINATES 1 0 0 0; 2 0 10 0; 3 10 0 0; 4 10 10 0; MEMBER INCIDENCES 1 1 2; 2 2 4; 3 3 4; DEFINE MATERIAL START ISOTROPIC CONCRETE E 453600 POISSON 0.17 DENSITY 0.14999

ALPHA 5.5e-006 DAMP 0.05 END DEFINE MATERIAL MEMBER PROPERTY AMERICAN 1 TO 3 PRIS YD 1 ZD 1

CONSTANTS MATERIAL CONCRETE ALL

SUPPORTS 1 3 ELASTIC FOOTING 10 10 DIRECT Y SUBGRADE 144 LOAD 1 LOADTYPE None TITLE LOAD CASE 1 JOINT LOAD 2 4 FY -10 PERFORM ANALYSIS PRINT ALL FINISH

Appendix B STAAD SPACE START JOB INFORMATION ENGINEER DATE 19-Mar-09 END JOB INFORMATION INPUT WIDTH 79 UNIT FEET KIP

JOINT COORDINATES 1 0 0 0; 2 80 0 0; 3 80 0 80; 4 0 0 80; 5 4 0 0; 6 4 0 4; 7 0 0 4; 8 8 0 0; 9 8 0 4; 10 12 0 0; 11 12 0 4; 12 16 0 0; 13 16 0 4; 14 20 0 0; 15 20 0 4; 16 24 0 0; 17 24 0 4; 18 28 0 0; 19 28 0 4; 20 32 0 0; 21 32 0 4; 22 36 0 0; 23 36 0 4; 24 40 0 0; 25 40 0 4; 26 44 0 0; 27 44 0 4; 28 48 0 0; 29 48 0 4; 30 52 0 0; 31 52 0 4; 32 56 0 0; 33 56 0 4; 34 60 0 0; 35 60 0 4; 36 64 0 0; 37 64 0 4; 38 68 0 0; 39 68 0 4; 40 72 0 0; 41 72 0 4; 42 76 0 0; 43 76 0 4; 44 80 0 4; 45 4 0 8; 46 0 0 8; 47 8 0 8; 48 12 0 8; 49 16 0 8; 50 20 0 8; 51 24 0 8; 52 28 0 8; 53 32 0 8; 54 36 0 8; 55 40 0 8; 56 44 0 8; 57 48 0 8; 58 52 0 8; 59 56 0 8; 60 60 0 8; 61 64 0 8; 62 68 0 8; 63 72 0 8; 64 76 0 8; 65 80 0 8; 66 4 0 12; 67 0 0 12; 68 8 0 12; 69 12 0 12; 70 16 0 12; 71 20 0 12; 72 24 0 12; 73 28 0 12; 74 32 0 12; 75 36 0 12; 76 40 0 12; 77 44 0 12; 78 48 0 12; 79 52 0 12; 80 56 0 12; 81 60 0 12; 82 64 0 12; 83 68 0 12; 84 72 0 12; 85 76 0 12; 86 80 0 12; 87 4 0 16; 88 0 0 16; 89 8 0 16; 90 12 0 16; 91 16 0 16; 92 20 0 16; 93 24 0 16; 94 28 0 16; 95 32 0 16; 96 36 0 16; 97 40 0 16; 98 44 0 16; 99 48 0 16; 100 52 0 16; 101 56 0 16; 102 60 0 16; 103 64 0 16; 104 68 0 16; 105 72 0 16; 106 76 0 16; 107 80 0 16; 108 4 0 20; 109 0 0 20; 110 8 0 20; 111 12 0 20; 112 16 0 20; 113 20 0 20; 114 24 0 20; 115 28 0 20; 116 32 0 20; 117 36 0 20; 118 40 0 20; 119 44 0 20; 120 48 0 20; 121 52 0 20; 122 56 0 20; 123 60 0 20; 124 64 0 20; 125 68 0 20; 126 72 0 20; 127 76 0 20; 128 80 0 20; 129 4 0 24; 130 0 0 24; 131 8 0 24; 132 12 0 24; 133 16 0 24;

134 20 0 24; 135 24 0 24; 136 28 0 24; 137 32 0 24; 138 36 0 24; 139 40 0 24; 140 44 0 24; 141 48 0 24; 142 52 0 24; 143 56 0 24; 144 60 0 24; 145 64 0 24; 146 68 0 24; 147 72 0 24; 148 76 0 24; 149 80 0 24; 150 4 0 28; 151 0 0 28; 152 8 0 28; 153 12 0 28; 154 16 0 28; 155 20 0 28; 156 24 0 28; 157 28 0 28; 158 32 0 28; 159 36 0 28; 160 40 0 28; 161 44 0 28; 162 48 0 28; 163 52 0 28; 164 56 0 28; 165 60 0 28; 166 64 0 28; 167 68 0 28; 168 72 0 28; 169 76 0 28; 170 80 0 28; 171 4 0 32; 172 0 0 32; 173 8 0 32; 174 12 0 32; 175 16 0 32; 176 20 0 32; 177 24 0 32; 178 28 0 32; 179 32 0 32; 180 36 0 32; 181 40 0 32; 182 44 0 32; 183 48 0 32; 184 52 0 32; 185 56 0 32; 186 60 0 32; 187 64 0 32; 188 68 0 32; 189 72 0 32; 190 76 0 32; 191 80 0 32; 192 4 0 36; 193 0 0 36; 194 8 0 36; 195 12 0 36; 196 16 0 36; 197 20 0 36; 198 24 0 36; 199 28 0 36; 200 32 0 36; 201 36 0 36; 202 40 0 36; 203 44 0 36; 204 48 0 36; 205 52 0 36; 206 56 0 36; 207 60 0 36; 208 64 0 36; 209 68 0 36; 210 72 0 36; 211 76 0 36; 212 80 0 36; 213 4 0 40; 214 0 0 40; 215 8 0 40; 216 12 0 40; 217 16 0 40; 218 20 0 40; 219 24 0 40; 220 28 0 40; 221 32 0 40; 222 36 0 40; 223 40 0 40; 224 44 0 40; 225 48 0 40; 226 52 0 40; 227 56 0 40; 228 60 0 40; 229 64 0 40; 230 68 0 40; 231 72 0 40; 232 76 0 40; 233 80 0 40; 234 4 0 44; 235 0 0 44; 236 8 0 44; 237 12 0 44; 238 16 0 44; 239 20 0 44; 240 24 0 44; 241 28 0 44; 242 32 0 44; 243 36 0 44; 244 40 0 44; 245 44 0 44; 246 48 0 44; 247 52 0 44; 248 56 0 44; 249 60 0 44; 250 64 0 44; 251 68 0 44; 252 72 0 44; 253 76 0 44;

254 80 0 44; 255 4 0 48; 256 0 0 48; 257 8 0 48; 258 12 0 48; 259 16 0 48; 260 20 0 48; 261 24 0 48; 262 28 0 48; 263 32 0 48; 264 36 0 48; 265 40 0 48; 266 44 0 48; 267 48 0 48; 268 52 0 48; 269 56 0 48; 270 60 0 48; 271 64 0 48; 272 68 0 48; 273 72 0 48; 274 76 0 48; 275 80 0 48; 276 4 0 52; 277 0 0 52; 278 8 0 52; 279 12 0 52; 280 16 0 52; 281 20 0 52; 282 24 0 52; 283 28 0 52; 284 32 0 52; 285 36 0 52; 286 40 0 52; 287 44 0 52; 288 48 0 52; 289 52 0 52; 290 56 0 52; 291 60 0 52; 292 64 0 52; 293 68 0 52; 294 72 0 52; 295 76 0 52; 296 80 0 52; 297 4 0 56; 298 0 0 56; 299 8 0 56; 300 12 0 56; 301 16 0 56; 302 20 0 56; 303 24 0 56; 304 28 0 56; 305 32 0 56; 306 36 0 56; 307 40 0 56; 308 44 0 56; 309 48 0 56; 310 52 0 56; 311 56 0 56; 312 60 0 56; 313 64 0 56; 314 68 0 56; 315 72 0 56; 316 76 0 56; 317 80 0 56; 318 4 0 60; 319 0 0 60; 320 8 0 60; 321 12 0 60; 322 16 0 60; 323 20 0 60; 324 24 0 60; 325 28 0 60; 326 32 0 60; 327 36 0 60; 328 40 0 60; 329 44 0 60; 330 48 0 60; 331 52 0 60; 332 56 0 60; 333 60 0 60; 334 64 0 60; 335 68 0 60; 336 72 0 60; 337 76 0 60; 338 80 0 60; 339 4 0 64; 340 0 0 64; 341 8 0 64; 342 12 0 64; 343 16 0 64; 344 20 0 64; 345 24 0 64; 346 28 0 64; 347 32 0 64; 348 36 0 64; 349 40 0 64; 350 44 0 64; 351 48 0 64; 352 52 0 64; 353 56 0 64; 354 60 0 64; 355 64 0 64; 356 68 0 64; 357 72 0 64; 358 76 0 64; 359 80 0 64; 360 4 0 68; 361 0 0 68; 362 8 0 68; 363 12 0 68; 364 16 0 68; 365 20 0 68; 366 24 0 68; 367 28 0 68; 368 32 0 68; 369 36 0 68; 370 40 0 68; 371 44 0 68; 372 48 0 68; 373 52 0 68;

374 56 0 68; 375 60 0 68; 376 64 0 68; 377 68 0 68; 378 72 0 68; 379 76 0 68; 380 80 0 68; 381 4 0 72; 382 0 0 72; 383 8 0 72; 384 12 0 72; 385 16 0 72; 386 20 0 72; 387 24 0 72; 388 28 0 72; 389 32 0 72; 390 36 0 72; 391 40 0 72; 392 44 0 72; 393 48 0 72; 394 52 0 72; 395 56 0 72; 396 60 0 72; 397 64 0 72; 398 68 0 72; 399 72 0 72; 400 76 0 72; 401 80 0 72; 402 4 0 76; 403 0 0 76; 404 8 0 76; 405 12 0 76; 406 16 0 76; 407 20 0 76; 408 24 0 76; 409 28 0 76; 410 32 0 76; 411 36 0 76; 412 40 0 76; 413 44 0 76; 414 48 0 76; 415 52 0 76; 416 56 0 76; 417 60 0 76; 418 64 0 76; 419 68 0 76; 420 72 0 76; 421 76 0 76; 422 80 0 76; 423 4 0 80; 424 8 0 80; 425 12 0 80; 426 16 0 80; 427 20 0 80; 428 24 0 80; 429 28 0 80; 430 32 0 80; 431 36 0 80; 432 40 0 80; 433 44 0 80; 434 48 0 80; 435 52 0 80; 436 56 0 80; 437 60 0 80; 438 64 0 80; 439 68 0 80; 440 72 0 80; 441 76 0 80;

ELEMENT INCIDENCES SHELL 7 1 5 6 7; 9 5 8 9 6; 11 8 10 11 9; 13 10 12 13 11; 15 12 14 15 13; 17 14 16 17 15; 19 16 18 19 17; 21 18 20 21 19; 23 20 22 23 21; 25 22 24 25 23; 27 24 26 27 25; 29 26 28 29 27; 31 28 30 31 29; 33 30 32 33 31; 35 32 34 35 33; 37 34 36 37 35; 39 36 38 39 37; 41 38 40 41 39; 43 40 42 43 41; 45 42 2 44 43; 47 7 6 45 46; 48 6 9 47 45; 49 9 11 48 47; 50 11 13 49 48; 51 13 15 50 49; 52 15 17 51 50; 53 17 19 52 51; 54 19 21 53 52; 55 21 23 54 53; 56 23 25 55 54; 57 25 27 56 55; 58 27 29 57 56; 59 29 31 58 57;

60 31 33 59 58; 61 33 35 60 59; 62 35 37 61 60; 63 37 39 62 61; 64 39 41 63 62; 65 41 43 64 63; 67 43 44 65 64; 69 46 45 66 67; 70 45 47 68 66; 71 47 48 69 68; 72 48 49 70 69; 73 49 50 71 70; 74 50 51 72 71; 75 51 52 73 72; 76 52 53 74 73; 77 53 54 75 74; 78 54 55 76 75; 79 55 56 77 76; 80 56 57 78 77; 81 57 58 79 78; 82 58 59 80 79; 83 59 60 81 80; 84 60 61 82 81; 85 61 62 83 82; 86 62 63 84 83; 87 63 64 85 84; 89 64 65 86 85; 91 67 66 87 88; 92 66 68 89 87; 93 68 69 90 89; 94 69 70 91 90; 95 70 71 92 91; 96 71 72 93 92; 97 72 73 94 93; 98 73 74 95 94; 99 74 75 96 95; 100 75 76 97 96; 101 76 77 98 97; 102 77 78 99 98; 103 78 79 100 99; 104 79 80 101 100; 105 80 81 102 101; 106 81 82 103 102; 107 82 83 104 103; 108 83 84 105 104; 109 84 85 106 105; 111 85 86 107 106; 113 88 87 108 109; 114 87 89 110 108; 115 89 90 111 110; 116 90 91 112 111; 117 91 92 113 112; 118 92 93 114 113; 119 93 94 115 114; 120 94 95 116 115; 121 95 96 117 116; 122 96 97 118 117; 123 97 98 119 118; 124 98 99 120 119; 125 99 100 121 120; 126 100 101 122 121; 127 101 102 123 122; 128 102 103 124 123; 129 103 104 125 124; 130 104 105 126 125; 131 105 106 127 126; 133 106 107 128 127; 135 109 108 129 130; 136 108 110 131 129; 137 110 111 132 131; 138 111 112 133 132; 139 112 113 134 133; 140 113 114 135 134; 141 114 115 136 135; 142 115 116 137 136; 143 116 117 138 137; 144 117 118 139 138; 145 118 119 140 139; 146 119 120 141 140; 147 120 121 142 141; 148 121 122 143 142; 149 122 123 144 143;

150 123 124 145 144; 151 124 125 146 145; 152 125 126 147 146; 153 126 127 148 147; 155 127 128 149 148; 157 130 129 150 151; 158 129 131 152 150; 159 131 132 153 152; 160 132 133 154 153; 161 133 134 155 154; 162 134 135 156 155; 163 135 136 157 156; 164 136 137 158 157; 165 137 138 159 158; 166 138 139 160 159; 167 139 140 161 160; 168 140 141 162 161; 169 141 142 163 162; 170 142 143 164 163; 171 143 144 165 164; 172 144 145 166 165; 173 145 146 167 166; 174 146 147 168 167; 175 147 148 169 168; 177 148 149 170 169; 179 151 150 171 172; 180 150 152 173 171; 181 152 153 174 173; 182 153 154 175 174; 183 154 155 176 175; 184 155 156 177 176; 185 156 157 178 177; 186 157 158 179 178; 187 158 159 180 179; 188 159 160 181 180; 189 160 161 182 181; 190 161 162 183 182; 191 162 163 184 183; 192 163 164 185 184; 193 164 165 186 185; 194 165 166 187 186; 195 166 167 188 187; 196 167 168 189 188; 197 168 169 190 189; 199 169 170 191 190; 201 172 171 192 193; 202 171 173 194 192; 203 173 174 195 194; 204 174 175 196 195; 205 175 176 197 196; 206 176 177 198 197; 207 177 178 199 198; 208 178 179 200 199; 209 179 180 201 200; 210 180 181 202 201; 211 181 182 203 202; 212 182 183 204 203; 213 183 184 205 204; 214 184 185 206 205; 215 185 186 207 206; 216 186 187 208 207; 217 187 188 209 208; 218 188 189 210 209; 219 189 190 211 210; 221 190 191 212 211; 223 193 192 213 214; 224 192 194 215 213; 225 194 195 216 215; 226 195 196 217 216; 227 196 197 218 217; 228 197 198 219 218; 229 198 199 220 219;

230 199 200 221 220; 231 200 201 222 221; 232 201 202 223 222; 233 202 203 224 223; 234 203 204 225 224; 235 204 205 226 225; 236 205 206 227 226; 237 206 207 228 227; 238 207 208 229 228; 239 208 209 230 229; 240 209 210 231 230; 241 210 211 232 231; 243 211 212 233 232; 245 214 213 234 235; 246 213 215 236 234; 247 215 216 237 236; 248 216 217 238 237; 249 217 218 239 238; 250 218 219 240 239; 251 219 220 241 240; 252 220 221 242 241; 253 221 222 243 242; 254 222 223 244 243; 255 223 224 245 244; 256 224 225 246 245; 257 225 226 247 246; 258 226 227 248 247; 259 227 228 249 248; 260 228 229 250 249; 261 229 230 251 250; 262 230 231 252 251; 263 231 232 253 252; 265 232 233 254 253; 267 235 234 255 256; 268 234 236 257 255; 269 236 237 258 257; 270 237 238 259 258; 271 238 239 260 259; 272 239 240 261 260; 273 240 241 262 261; 274 241 242 263 262; 275 242 243 264 263; 276 243 244 265 264; 277 244 245 266 265; 278 245 246 267 266; 279 246 247 268 267; 280 247 248 269 268; 281 248 249 270 269; 282 249 250 271 270; 283 250 251 272 271; 284 251 252 273 272; 285 252 253 274 273; 287 253 254 275 274; 289 256 255 276 277; 290 255 257 278 276; 291 257 258 279 278; 292 258 259 280 279; 293 259 260 281 280; 294 260 261 282 281; 295 261 262 283 282; 296 262 263 284 283; 297 263 264 285 284; 298 264 265 286 285; 299 265 266 287 286; 300 266 267 288 287; 301 267 268 289 288; 302 268 269 290 289; 303 269 270 291 290; 304 270 271 292 291; 305 271 272 293 292; 306 272 273 294 293; 307 273 274 295 294;

309 274 275 296 295; 311 277 276 297 298; 312 276 278 299 297; 313 278 279 300 299; 314 279 280 301 300; 315 280 281 302 301; 316 281 282 303 302; 317 282 283 304 303; 318 283 284 305 304; 319 284 285 306 305; 320 285 286 307 306; 321 286 287 308 307; 322 287 288 309 308; 323 288 289 310 309; 324 289 290 311 310; 325 290 291 312 311; 326 291 292 313 312; 327 292 293 314 313; 328 293 294 315 314; 329 294 295 316 315; 331 295 296 317 316; 333 298 297 318 319; 334 297 299 320 318; 335 299 300 321 320; 336 300 301 322 321; 337 301 302 323 322; 338 302 303 324 323; 339 303 304 325 324; 340 304 305 326 325; 341 305 306 327 326; 342 306 307 328 327; 343 307 308 329 328; 344 308 309 330 329; 345 309 310 331 330; 346 310 311 332 331; 347 311 312 333 332; 348 312 313 334 333; 349 313 314 335 334; 350 314 315 336 335; 351 315 316 337 336; 353 316 317 338 337; 355 319 318 339 340; 356 318 320 341 339; 357 320 321 342 341; 358 321 322 343 342; 359 322 323 344 343; 360 323 324 345 344; 361 324 325 346 345; 362 325 326 347 346; 363 326 327 348 347; 364 327 328 349 348; 365 328 329 350 349; 366 329 330 351 350; 367 330 331 352 351; 368 331 332 353 352; 369 332 333 354 353; 370 333 334 355 354; 371 334 335 356 355; 372 335 336 357 356; 373 336 337 358 357; 375 337 338 359 358; 377 340 339 360 361; 378 339 341 362 360; 379 341 342 363 362; 380 342 343 364 363; 381 343 344 365 364; 382 344 345 366 365; 383 345 346 367 366; 384 346 347 368 367; 385 347 348 369 368; 386 348 349 370 369; 387 349 350 371 370;

388 350 351 372 371; 389 351 352 373 372; 390 352 353 374 373; 391 353 354 375 374; 392 354 355 376 375; 393 355 356 377 376; 394 356 357 378 377; 395 357 358 379 378; 397 358 359 380 379; 399 361 360 381 382; 400 360 362 383 381; 401 362 363 384 383; 402 363 364 385 384; 403 364 365 386 385; 404 365 366 387 386; 405 366 367 388 387; 406 367 368 389 388; 407 368 369 390 389; 408 369 370 391 390; 409 370 371 392 391; 410 371 372 393 392; 411 372 373 394 393; 412 373 374 395 394; 413 374 375 396 395; 414 375 376 397 396; 415 376 377 398 397; 416 377 378 399 398; 417 378 379 400 399; 419 379 380 401 400; 421 382 381 402 403; 422 381 383 404 402; 423 383 384 405 404; 424 384 385 406 405; 425 385 386 407 406; 426 386 387 408 407; 427 387 388 409 408; 428 388 389 410 409; 429 389 390 411 410; 430 390 391 412 411; 431 391 392 413 412; 432 392 393 414 413; 433 393 394 415 414; 434 394 395 416 415; 435 395 396 417 416; 436 396 397 418 417; 437 397 398 419 418; 438 398 399 420 419; 439 399 400 421 420; 441 400 401 422 421; 443 403 402 423 4; 445 402 404 424 423; 447 404 405 425 424; 449 405 406 426 425; 451 406 407 427 426; 453 407 408 428 427; 455 408 409 429 428; 457 409 410 430 429; 459 410 411 431 430; 461 411 412 432 431; 463 412 413 433 432; 465 413 414 434 433; 467 414 415 435 434; 469 415 416 436 435; 471 416 417 437 436; 473 417 418 438 437; 475 418 419 439 438; 477 419 420 440 439; 479 420 421 441 440; 480 421 422 3 441;

ELEMENT PROPERTY 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 TO 65 67 69 TO 87 89 91 TO 109 111 113 TO 131 133 135 TO 153 155 157 TO 175 177 179 TO 197 199 201 TO 219 221 223 TO 241 243 245 TO 263 265 267 TO 285 287 289 TO 307 309 311 TO 329 331 333 TO 351 353 355 TO 373 375 377 TO 395 397 399 TO 417 419 421 TO 439 441 443 445 447 449 451 453 455 457 459 461 463 465 467 469 471 473 475 477 479 480 THICKNESS 1

DEFINE MATERIAL START ISOTROPIC CONCRETE E 453600 POISSON 0.17 DENSITY 0.14999 ALPHA 5.5e-006 DAMP 0.05 END DEFINE MATERIAL CONSTANTS MATERIAL CONCRETE ALL

SUPPORTS 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 TO 65 -

67 69 TO 87 89 91 TO 109 111 113 TO 131 133 135 TO 153 155 157 TO 175 177 179 TO 197 199 201 TO 219 221 223 TO 241 243 245 TO 263 265 267 TO 285 287 289 TO 307 309 311 TO 329 331 333 TO 351 353 355 TO 373 375 377 TO 395 397 399 TO 417 419 421 TO 439 441 443 445 447 449 451 453 455 457 459 461 463 465 467 469 471 473 475 477 479 480 PLATE MAT DIRECT Y SUBGRADE 144 PRINT COMPRESSION LOAD 1 LOADTYPE None TITLE LOAD CASE 1 ELEMENT LOAD 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 TO 65 67 69 TO 87 89 91 TO 109 111 113 TO 131 133 135 TO 153 155 157 TO 175 177 179 TO 197 199 201 TO 219 221 223 TO 241 243 245 TO 263 265 267 TO 285 287 289 TO 307 309 311 TO 329 331 333 TO 351 353 355 TO 373 375 377 TO 395 397 399 TO 417 419 421 TO 439 441 443 445 447 449 451 453 455 457 459 461 463 465 467 469 471 473 475 477 479 480 PR GY -0.2 PERFORM ANALYSIS PRINT ALL FINISH

After opening STAAD software whose latest version is STAADV8i following options are available.

1 a b c d e f 2

”Project task” which includes New project Open project Open from filewise Configuration Backup manager License management A begineer may use New project option and after he gains some momentum he can try

out with other options..

3 Recent file 4 License Configuration Under liscence configuration all international codes are given.User need to select the code with which he will design and for every code there is a liscense required…Also in this column one option is there which is called “Advance STAAD engine” …Please note activating this facility liscence need to be obtained for Bentley by paying extra cost for this…The advantage of this facility is that it reduces the time required for analysis and numerous degree of freedom of a structure are involved…This facility reduces the zeros in the stiffness matrix there by saving time required for analysis…

Modelling Next comes the modeling option..Different people have different ways of modeling…

After selecting the type of frame one is interested…which includes plane,space,floor and truss,model can be created in following ways, 1 In pulldown menu of STAAD in Geometry option one has the option of “Run structural wizard”..One can model the structure using this..

2 By typing the coordinates nodes can be created which later can be connected by members to form a frame..

3 Also there are options like copy(by clicking right click of mouse) and in pulldown menu “geometry option where “translational repeat command” is there..which also can be used to create a model..

After creating the model support specification needs to be given to the structure…for which support command can be used…

Next step involve defining the property which can be done using property dialog box..wherein there is option of “Define” “section database” and user table.Define command is generally used for RCC structure and database contains all standard steel section of different counties..However if we have any buildup structure ..this property can be given using “user table”..

Next steps involves “Applying the load”

Load command has many options a b c d

Member load Joint load Floor load Hydrostatic load etc..

Next load combination needs to be done…

Analysis After applying the load..user need to give the command “perform analysis” followed by “Run analysis”…

After this analysis is done ..one can check support reaction,bending moment ,shear force ,deflection etc…

Please note this is just a beginning..There are many other aspect..like applying seismic load,wind load,moving load,time history load,P delta analysis …once a user gains a momentum he can slowly proceed with this aspects…

Design In design respective codes needs to be selected and following parameter needs to be applied depending on the suitably..

Designing parameter:

Parameter Description Name FYM AIN

Yield Stress for main reinforcing steel.

FYS EC

Yield Stress for secondary reinforcing steel.

FC

Concrete Yield Stress.

CLE AR

For beam members.

For column members

MINM AIN

Minimum main reinforcement bar size.

MAXM AIN

Maximum main reinforcement bar size.

MINS EC

Minimum secondary reinforcement bar size.

MAXS EC

Maximum secondary reinforcement bar size.

BEAM DESIGN A value of 1.0 means the effect of axial force will be taken into account for beam design.

BRA CING

COLUMN DESIGN A value of 1.0 means the column is unbraced about major axis.

A value of 2.0 means the column is unbraced about minor axis.

A value of 3.0 means the column is unbraced about both axis.

RAT IO

Maximum percentage of longitudinal reinforcement in columns.

RFACE

A value of 4.0 means longitudinal reinforcement in column is arranged equally along 4 faces.

A value of 2.0 invokes 2 faced distribution about major axis.

A value of 3.0 invokes 2 faced distribution about minor axis.

WIDTH

Width to be used for design. This value defaults to ZD as provided under MEMBER PROPERTIES.

DEPTH

Total depth to be used for design. This value defaults to YD as provided under MEMBER PROPERTIES.

TRACK

BEAM DESIGN: For TRACK = 0.0, output consists of reinforcement details at START, MIDDLE and END. For TRACK = 1.0, critical moments are printed in addition to TRACK 0.0 output.

For TRACK = 2.0, required steel for intermediate sections defined by NSECTION are printed in addition to TRACK 1.0 output.

COLUMN DESIGN: With TRACK = 0.0, reinforcement details are printed.

With TRACK = 1.0, column interaction analysis results are printed in

addition to TRACK 0.0 output.

With TRACK = 2.0, a schematic interaction diagram and intermediate interaction values are printed in addition to TRACK 1.0 output.

With TRACK = 9.0, the details of section capacity calculations are printed.

REINF

Tied column. A value of 1.0 will mean spiral reinforcement.

ELZ

Ratio of effective length to actual length of column about major axis.

ELZ

Ratio of effective length to actual length of column about major axis.

ULY

Ratio of unsupported length to actual length of column about minor axis.

ULZ

Ratio of unsupportd length to actual length of column about major axis.

A value of 0.0 means torsion to be considered in beam design.

TORSION A value of 1.0 means torsion to be neglected in beam design.

Minimum clear distance between main reinforcing bars in beam and SPSMAIN column. For column centre to centre distance between main bars cannot exceed 300mm.

SFACE

Face of support location at start of beam. It is used to check against shear at the face of the support in beam design. The parameter can also be used to check against shear at any point from the start of the member.

EFACE

Face of support location at end of beam. The parameter can also be used to check against shear at any point from the end of the member. (Note: Both SFACE and EFACE are input as positive numbers).

Perform shear check against enhanced shear strength as per Cl. 40.5 of IS456:2000.

ENSH

ENSH = 1.0 means ordinary shear check to be performed ( no enhancement of shear strength at sections close to support)

For ENSH = a positive value(say x ), shear strength will be enhanced upto a distance x from the start of the member. This is used only when a span of a beam is subdivided into two or more parts. (Refer note ) For ENSH = a negative value(say â&#x20AC;&#x201C;y), shear strength will be enhanced

upto a distance y from the end of the member. This is used only when a span of a beam is subdivided into two or more parts.(Refer note) If default value (0.0) is used the program will calculate Length to Overall Depth ratio. If this ratio is greater than 2.5, shear strength will be enhanced at sections (<2d) close to support otherwise ordinary shear check will be performed.

RENSH

Distance of the start or end point of the member from its nearest support.

This parameter is used only when a span of a beam is subdivided into two or more parts.

.

Next design beam and column option needs to be given..

Please note while modeling one uses “Global coordinate axis” and the results are in “Local coordinate axis”. This convention are given in STAAD help menu…

In a nutshell STAAD involves the following Creating a structural model. This consists of generating the structural geometry, specifying member properties, material constants, loads, analysis and design specifications, etc  Visualization and verification of the model geometry  Running the STAAD analysis to perform analysis and design  Verification of results - graphically and numerically  Report generation and printing The best way of learning STAAD is through help menu of STAAD .STAAD is a user friendly package and graphical user interface of STAAD is superb

SURFACE ELEMENT In STAAD, a surface entity is an object that represents a collection of elements. When the program goes through the analysis phase, it subdivides the surface into a number of elements by itself. This process is called meshing or mesh generation. But during the modeling phase, the user does not see any of those elements which keeps the model small and easy to manage. An entire wall is hence represented by just a few "Surface" entities, instead of hundreds of plate elements.

The advantage of using surfaces is that the minute details involved in the process of converting a physical object like a wall or slab into the mathematical model which consists of plate elements is something that the user doesn't have to bother with. However, in many situations, not knowing these details can lead to errors, some of which are impossible to detect because the underlying elements cannot be seen graphically. Also, not knowing how many elements will be generated during the meshing process can lead to unwanted consequences such as a massive increase in the size of the model, to a point where the program simply cannot handle such a massive volume of data. Consequently, we recommend that surfaces be not used as much as possible.

There is however one situation where the user has no choice but to use surfaces. That is when he/she wants to perform reinforced concrete design of a shearwall per the ACI, British or Indian codes. STAAD can perform a shearwall design if and only if that wall is modeled using STAAD's SURFACE entity.

When you use surfaces in your model, the resulting mesh of finite elements is not easily apparent. In fact, the only place in the program where you get a good view of the meshed state of the surface is in the post-processing mode in the node displacement page.

The inability to view the meshed state of the surface makes it very difficult to see the flaws in the modeling. In your structure for example, there may be members which are sharing space with the surface. Unless those members get meshed automatically along with the surface, and more importantly, unless the surface and member meshing is done in such a manner than all the resulting pieces are connected to each other properly, there is no assurance that the members and surface will be able to transfer loads to each other. The inability to see their meshed condition makes it difficult to see if the meshing is done properly. Replacing the surface with quadrilateral elements, and meshing those element is a way to get around the problem. So when you wish to model a floor slab, roof or a wall that does not need to be designed as a shear wall, we recommend that you use plate elements. In our view, the only drawback of using plates is that you need several of them to model a wall or a slab, and that increases the size of the input data.

But at least you can detect and remove every error in the model, and know exactly how many elements and nodes there are in that model.

Some aspects to consider when analysing mat foundations using STAAD.Pro Created by Kris Sathia, Technical Support Group, Bentley Systems, Inc. Question: I am using STAAD.Pro to analyze a mat foundation that supports a steel frame. I have used the PLATE MAT command and set the springs to COMPRESSION only. I encounter 2 problems :- a) Instability warnings b) Some springs still go into tension How do I go about correcting these problems?

Answer: In order to solve problems of this type, there are two aspects that one needs to pay attention to.

1. Solving pure component load cases Let us assume that there are 4 primary load cases. Load cases 1 and 2 are vertical load cases (downward loads along GY), 3 is wind along X (Nodal forces along global X), 4 is wind along Z (Nodal forces along global Z).

Consider the load cases 3 and 4. They contain only lateral forces. Cases such as these are called component-type primary cases because they represent only one type of load - wind only, seismic only, etc. In the real world, a component type load acts in conjunction with other cases such as gravity. Thus, solving a pure component case is useful only when the results for that case can be combined with those from gravity and other load cases for a steel design for example. But this requires the principle of superposition to be applicable for that analysis run. The principle of superposition states that Results of case A + Results of case B = Results of (case A + case B) This principle works only for static linear conditions.

Load cases 3 and 4 produce an overturning moment. To satisfy equilibrium, a restoring moment needs to be mobilized to counteract this overturning moment. In these load cases, in addition to the horizontal forces, had there been loads acting vertically downwards, they would have contributed towards a restoring moment. But such loads are not present.

So, the contribution to restoring must come solely from the soil springs. Normally, this is formed when some springs go into compression and others go into tension thus forming a couple. But, by declaring the soil springs as compression-only, the tensile force in the springs are disallowed. Thus, a restoring moment cannot be formed solely by the spring forces. It leads to the instability warnings.

Consequently, a component load case containing only horizontal forces that produce an overturning moment cannot be resisted by a system of soil springs in which a tensile force in the soil spring is disallowed.

There are two ways to address this situation.

1. Instruct the program to "not" solve such load cases. The means to do that is to convert them into "REFERENCE LOAD DATA" which is explained in section 5.31.6 of the Technical Reference manual.

2. Instruct the program to solve load cases 1 through 4 without the "COMPRESSION" attribute. That attribute can be specified later when the combination cases are solved, as explained next. The PERFORM ANALYSIS and CHANGE commands should also be specified after load case 4. Since the results of these component cases are of no use to us, we will dis-regard them. Thus, we will have something like this.

MEMBER PROPERTIES ..

CONSTANTS ..

MEMBER RELEASE ..

SUPPORTS 1 TO 126 PLATE MAT DIRECTION Y SUBGRADE 12.0 LOAD 1 DEAD LOAD SELF Y -1.0 LOAD 2 LIVE LOAD MEMBER LOAD LOAD 3 WIND IN X JOINT LOAD 35 TO 46 FX 0.6 LOAD 4 WIND IN Z JOINT LOAD 31 TO 67 FZ 0.35 PERFORM ANALYSIS CHANGE

2. Solving combination load cases The second aspect to consider in these models is the type of command to use when combining the individual cases to form combination cases. Most people typically use the syntax LOAD COMBINATION nnn. This instructs STAAD to find the result for a combination case by adding the results of the component primary cases that make up that combination case. In other words, LOAD COMBINATION 7 1 1.0 2 1.0 instructs the program to fetch the results of load cases 1 and 2 and add them algebraically to produce the results of load case 7. An analysis involving the equation [K]{d}={P} is not being done when this syntax is used.

This approach is OK to use only under linear conditions in which the laws of superposition work.

In non-linear conditions such as when COMPRESSION-only springs are present in the model, this principle does not work.

So, instead of adding the results, the program must be instructed to form a physical load case called 7 which contains the load items of cases 1 and 2 factored by 1.0 and perform the operation [K]{d}={P} where {P} is load case 7. This is the correct way to analyze the model for the loads of cases 1 and 2 acting simultaneously.

The means to achieve it is to use the REPEAT LOAD syntax instead of the LOAD COMBINATION syntax.

For example, the commands LOAD COMB 7 COMBINATION LOAD CASE 7 1 1.0 2 1.0 LOAD COMB 8 COMBINATION LOAD CASE 8 1 1.0 2 1.0 3 1.0 LOAD COMB 9 COMBINATION LOAD CASE 9 1 1.0 2 1.0 4 1.0 LOAD COMB 12 COMBINATION LOAD CASE 12 1 1.0 4 1.0 LOAD COMB 13 COMBINATION LOAD CASE 13 1 0.67 2 0.67 3 0.67 LOAD COMB 14 COMBINATION LOAD CASE 14 1 0.67 2 0.67 4 0.67 must be changed to

LOAD 7 COMBINATION LOAD CASE 7 REPEAT LOAD 1 1.0 2 1.0 LOAD 8 COMBINATION LOAD CASE 8 REPEAT LOAD 1 1.0 2 1.0 3 1.0 LOAD 9 COMBINATION LOAD CASE 9 REPEAT LOAD 1 1.0 2 1.0 4 1.0 LOAD 12 COMBINATION LOAD CASE 12 REPEAT LOAD 1 1.0 4 1.0 LOAD 13 COMBINATION LOAD CASE 13 REPEAT LOAD 1 0.67 2 0.67 3 0.67 LOAD 14 COMBINATION LOAD CASE 14 REPEAT LOAD 1 0.67 2 0.67 4 0.67 Additionally, since the COMPRESSION-only attribute was removed for cases 1 to 4, the SUPPORTS need to be re-specified just before load case 7 and the COMPRESSION attribute must be included in that command. The data will then look like LOAD 4 WIND IN Z JOINT LOAD 31 TO 67 FZ 0.35 PERFORM ANALYSIS CHANGE SUPPORTS 1 TO 126 PLATE MAT DIRECTION Y SUBGRADE 12.0 COMPRESSION LOAD 7 COMBINATION LOAD CASE 7 REPEAT LOAD 1 1.0 2 1.0 .. .. ..

LOAD 14 COMBINATION LOAD CASE 14 REPEAT LOAD 1 0.67 2 0.67 4 0.67 PERFORM ANALYSIS CHANGE LOAD LIST 7 TO 14 ..

PARAMETER CODE AISC UNIFIED 2010 METHOD ASD ..

I'm designing a cooling tower basin which is resting on soil. The size of the raft is 6m x 5m. I modelled the entire sructure in staad using plate elements. I'm confused in assigning the supports for the raft.

I assigned plate mat for the raft and gave the subgrade modulus.

But i'm confused on selecting the direction in that.

What the purpose of this directions in the support?

What is the difference between X and X only

Soil subgrade modulus shall be appllied in global vertical direction, or respective, local axis. Resistance offered by the subgrade soil can be availed in all six degerees for a soil strata depending on the type of soil and soil halfspace.Generally in stadd as the local and global axis can be varying from case to case this option is provided to facilitate and for graphical ease. one should be careful while provideng the stiffness in particular direction as this depends on axis in consideration

Having done many large and thick MAT (RAFT) Foundations with STAAD/PRO , I can easily help you with this. Note the following: 1) Get Modulus Of Subgrade Reaction Ks (PCI, Lb/inch**3) or in SI units N/mm**3 from a Soil Consultant. In USA this is based on a Load Test and not from some formula's.

2) Go to STAAD/PRO and generate your PLATE Element Model.

STAAD/PRO will ask you about this Ks and will convert in to SoilSpring Support by multiplying Ks (Kn/mm**3) with tributary area at each node. So now your Soil-Spring is in Kn/mm or Kn/m. See STAAD/PRO TECH. REFERENCE MANUAL Pages 380-383. You only generate Vertical Soil Springs Ky. Y is the Global Vertical Direction of the Structure Model. Do not worry about Local axis of Plate Elements. That you will need for Design Forces of Plate elements. X-Z being horizontal plane of your Global Structure Model.

3) Now let us say your superstructure seating on this Mat(Raft) has three direction Forces( that is the Normal Case) : FOR FX, FZ (Global Lateral Forces). Do hand Calculations in both Horizontal direction using PASSIVE PRESSURE RESISTANCE OF SOIL on Length and thickness of Raft. USE SUPPORT CONDITION AT PERIPHARY NODES: FIXED IN X and Z and free in Y (ROLLER). Otherwise your model will be unstable in Lateral Direction.

Do not input FX and FZ loads in to your STAAD/PRO model. Have a factor of safety (against sliding) of at least 2.0.

Use Coefficient Of Friction between Concrete and Soil if water table is very low (below bottom of Raft). Check with your soil consultant for the Uf (Friction) value.

Lareal Resistance RH = Passive Resistance of soil X Lenth or width of Mat X Thickness + Uf (Friction) X Area of Mat x Permanernt Dead Load (No Live Load).

Factor Of Safety against Sliding = RH/Total FX or FZ > 2.0

4) For Total Fv (Vertical Force) and Overturning Moment MZ (Global) or MX (Global) due to Latera Loads on Superstructure, use your RAFT STAAD/PRO Model. Appply MX and MZ as Upword and Down word forces at affected nodes

Plan plane is X-Z, Y is vertical up direction. (Values of Passive Pressure and Coeff. of Friction are assumed) : The Raft size is X= 100 Ft, Z =100 ft, Y = 5 ft. (Thickness) . Passive pressure coefficient is Kp= 2.0 ksf. Water Table is very much below bottom of Raft. Coefficient of Friction between bottom of Raft and Soil Uf = 0.3 , Total Permanent DL including weight of Raft DL = 100X100x5.0 X 0.15 (150.0 Lb/ft**3 weight of Concrete) = 7500.0 Kips DL from Super Structure (Including Weight of Super Structure) = 8000.0 Kips.

Total DL = 7500.0 + 8000.0 = 15500.0 Kips.

Later Resistance = RH = 100X5.0X2.0 = 1000.0 Kips + 15500.0x0.3 ( = 4650.0 Kips) Total RH = 1000.0 + 4650.0 = 5650.0 Kips.

With Factor Of Safety of 2.0 against sliding, Allowable Total Lateral Load on Super Structure FX or FZ = 5650.0/2.0 = 2825.0 Kips.

If Super structure Lateral Load is more than FX or FZ > 2825.0 Kips provide Shear Keys at the bottom of Raft or Thicken the Raft.

This hand calculation is so simple that I do not like what other engineers do, that is Provide Lateral Springs KX and KZ. Why would I use FULL 3-D STAAD/PRO Model to find out what is allowable lateral load on Super Structure? What is missing in above simple hand calculation to find out Capacity of Raft/Structure for Lateral Loads?

I need STAAD/PRO RAFT Model for Gravity Loads (DL, LL) and Overturning Moment due to Lateral Loads, MX and MZ (Wind and Seismic) analysis and Design, not for Lateral Loads.

I did many Large and Thick MAT/RAFT foundations using STAAD/PRO in USA.

These are propriety designs/calculations belongs to the company I worked for. Now I am in India and I cannot request a copy of STAAD/PRO runs of these MAT/RAFT Models. I cannot load a copy these STAAD/PRO Mat Foundation runs. Also I do not have a STAAD/PRO (Personal Copy) loaded on my computer. Otherwise I would have created a simple FEM RAFT STAAD/PRO Model and LOAD it here.