CONSTRUCTING ENVIRONMENTS
FINAL LOGBOOK (Week 01-12) Hongshuai Zhang (Thomas) / 688502 / TUTOR: BROOK
Knowledge Map (Week 01) Dead loads Live loads Compression
Tension
Settlement load
Collinear forces: occur along a straight line.
Occupancy load
Concurrent forces: lines of action intersecting at
Ground pressure
Force
Static Load
Thermal stresses
a common point. Nonconcurrent: lines of action
Water pressure
that
do
not
intersect at a common
Impact loads
Dynamic Load
Snow loads Rain loads
Representation
Wind load
Earthquake load
point.
The features of materials that we should know and think about:
Material Behaviour - isotropic or anisotropic
Strength - strong or weak
Sometimes
Steal is much stronger than timber and steal is quite strong in both compression and tension. The other
characteristics of compression and tension
materials are strong in compression such as brick and cement.
like pulling apart and push together by
Stiffness - Stiff, flexible, stretchy or floppy
pressure.
Other
Some materials are flexible such as rubber. Although rope is flexible it is not stiff and concrete is a kind of
differently
under
very stiff material.
anisotropic
Shape - mono-dimensional(linear), bi-dimensional(planar) or tridimensional(volumetric)
Economy & Sustainability
Some bi-dimensional(planar) material such as ship shelf and tridimensional(volumetric) shape like bricks.
We should know the price of the material. The
materials
have
materials the
forces
the
strong
behaviour so
they
situation of transportation and if it would bring the impact to the environment. How does the efficiency of the material to the constructing system such as timber can be used all over the Australia. (Information from: W01 m1 Introduction to Materials)
In enclosing space for habitation, the structural system of a building must be able to support two types of loads--static and dynamic. Static loads are assumed to be applied slowly to a structure until it reaches its peak value without fluctuating rapidly in magnitude or position. Under a static load, a structure respond slowly and its deformation reaches a peak when the static force is maximum. Dynamic loads are applied suddenly to a structure, often with rapid changes in magnitude and point of application. Under a dynamic load, a structure develops inertial forces in relation to its mass and its maximum deformation does not necessarily correspond to the maximum magnitude of the applied force. The two major types of dynamic loads are wind loads and earthquake loads. Static load - Dead loads & Live loads Live loads comprise any moving or movable loads on a structure resulting from occupancy, collected snow and water, or moving equipment. A live load typically acts vertically downward but may horizontally as well to reflect the dynamic nature of a moving load. Dead loads are static loads acting vertically downward on a structure, comprising the self-weight of building elements, fixtures, and equipment permanently attached to it.
Masonry Terminology
Header is a masonry unit laid horizontally with the
Wythe is a continuous vertical section of a masonry wall oe unit un thickness.
shorter end exposed or parallel to the surface.
Course is a continuous horizontal range of masonry units.
Rowlock is a brick laid horizontally on the longer
Collar joint is the vertical joint between two wythes of masonry.
edge with the shorter end exposed.
Bed joint is the horizontal joint between two masonry courses. The term bed may refer to the
Soldier id a brick laid vertically with the longer edge
underside of a masonry unit, or to the layer of mortar in which a masonry unit is laid.
face exposed.
Head joint is the vertical joint between two masonry units, perpendicular to the face of a wall.
Running bond, commonly used for cavity and veneer
Stretcher is a masonry unit laid horizontally with the longer edge exposed or parallel to the surface.
walls, is composed of overlapping stretchers. Common bond has a course of headers between every five or six courses of stretchers; also known as American bond.
Long-and-short work is an arrangement of rectangular quoins or jambstones set alternately horizontally and vertically.
A force is any influence that produces a change in the shape or movement of a body.
TENSION FORCES
It is considered to be a vector quantity possessing both magnitude and direction, represented
When an external load pulls on a structural member,
by an arrow whose length is proportional to the magnitude and whose orientation in space
the particles composing the material move apart and
represents the direction.
undergo tension.
Collinear forces occur along a straight line, the vector sum of which is the algebraic sum of the
Tension forces stretch and elongate the material.
magnitudes of the forces, acting along the same line of action.
The amount of elongation depends on the stiffness of the material, cross sectional area, and the magnitude of the load. COMPRESSION FORCES A compression force produces the opposite effect of a tension force. When an external load pushes on a structural member, the particles of the material compact together. Compression forces result in the shortening of the material.
Membranes structure X Skeletal Sports stadiums with large area but cheap Surface structure
Solid structure
Knowledge Map (Week 02)
-Early buildings
Roller joint
-Egypt, Great Wall
Allows horizontal movement Restrict vertical, rotation
-Stone, bricks Pin joint
Sydney opera house Structural System
Structural Joints
Skeletal structure
Allows rotation
-Common, frame systems
Restrict horizontal, vertical
-Very efficient way to transfer loads down through the ground
Fixed joint
Week 02 Restricts horizontal, vertical, rotation
Hybrid structure -Air integral
ESD Strategies
-Particular membrane called ETFE
Local materials, material efficiency, thermal mass, night air purging, solar energy, wind energy, cross ventilation, smart and design, insulation, water harvesting
Structural System
The manner in which we select, assemble, and
The structural system of a building is designed and constructed to support and transmit gravity and lateral
integrate
load safely to the ground without exceeding the allowable stresses in its members.(Columns, beams, and
construction should take into account the following
loading walls support floor and roof structures.)
factors:
Enclose System
Performance Requirements
The enclose system is the shell or envelop of a building, consisting of the roof,exterior walls, windows, and
-Structural compatibility, integration, and safety
doors.(Exterior walls and roofs also dampen noise and provide security and privacy for the occupants of a
Aesthetic Qualities
building. Doors provide physical access. Windows provide access yo light, air, and views.)
-Desired relationship of building to its site, adjacent
Mechanical Systems
properties, and neighborhood
The mechanical systems of a building provide essential services to a building.(The electrical system
Regulatory Constraints
controls, meters, and distributes it in a safe manner for power, lighting, security, and communication
-Compliance with zoning ordinances and building
systems.)
codes
the
various
building
systems
in
Economic Considerations -Initial cost comprising material, transportation, equipment,and labor costs Environmental Impact -Conversation of energy and resources through sitting and building design Construction Practices -Safety requirementts
Structural Systems
Arches are curved structures for spanning an opening, designed
Solar systems they have particular kinds of structural sections sociate with them. This
to support a vertical load primarily by axial compression. They
structure might be found early buildings from Athens, Egypt, the Great Wall of China where
transform the vertical forces of a supported load into inclined
people were working with stones, bricks or mud systems. Compression is the main action in
components and transmit them to abutments on either side of the
the structures.
archway.
Shell are thin, cured plate structures typically constructed of reinforced concrete. They are
Cable structures utilize the cable as the principle means of
shaped to transmit applied forces by membrane stresses-the compressive, tensile, and shear
support. Because cables have high tensile strength but offer no
stresses acting in the plane of their surface.
resistance to compression or bending, they must be used purely in tension. When subject to concentrated loads, the shape of a cable consists of straight-line segments. Under a uniformly distributed load, it will take on the shape of an inverted arch. Suspension structures utilize a network of cables suspended and presented between compression members to directly support applied loads.
Shell and thin, curved plate structure typically constructed of reinforced concrete. They are
The manner in which forces are transferred from one
shaped to transmit applied forces by membrane stresses-the compressive, tensile, and shear
structural element to the next and how a structural system
stresses acting in the plane of their surfaces. A shell can sustain relatively large forces if uniformly
performs as a whole depend to a great extent on the types
applied. Because of its thinness, however, a shell has little bending resistance and is unsuitable for
of joints and connections used. Structural elements can be
concentrated loads.
joined to each other in three ways. Butt joints allow one of
Plate structures are rigid, planar, usually monolithic structures that disperse applied loads in a
the elements to be continuous and usually require a third
multidirectional pattern, with the loads generally following the shortest and stiffest routes to the
mediating element to make the connection. Overlapping
supports. A common example of a structure is a reinforced concrete slab.
joints allows all of the connected elements to bypass each
Membranes are thin, flexible surfaces that carry loads primarily through the development of
other and be continuous across the joint. The joining
tensile stresses. They may be suspended or stretched between posts, or be supported by pressure.
elements can also be molded or shaped to form a structural connection. The connectors used to join the structural elements may be in the form of a point, a line or a surface. While linear and surface types of connector resist rotation, point connectors do not unless a series of them is distributed across a large surface area.
A beam simply supported by two columns is not capable of resisting lateral force unless it
Column are rigid, relatively slender structural members designed
is braced. If the joints connecting the columns and beams are capable of resisting both
primarily to support axial compressive loads applied to the ends of
forces and moments, then the assembly becomes a grid frame. Applied loads produce
the members. Relatively short, thick columns are subject to failure
axial, bending, and shear forces in all members of the frame because the rigid joints
by crushing rather than by buckling. Failure occurs when the direct
restrain the ends of the members from rotating freely. In addition, vertical loads cause a
stress from an axial load exceeds the compressive strength of the
rigid frame to develop horizontal thrusts as its base. A grid frame is statically
material available in the cross section. An eccentric load, however,
indeterminate and rigid only in its plane.
can produce bending and result in an uneven stress distribution in the section. Beams are rigid structural members designed to carry and transfer transverse loads across space to supporting elements. The nonconcurrent pattern of forces subjects a beam to bending and deflection, which must be resisted by the internal strength of the material. A truss is a structural frame based on the geometric rigidity of the triangle and composed of linear members subject only to axial tension or compression.
Knowledge Map (Week 03) -Concrete Foundation Walls
-Strip Footings -Isolated Footings -Stepped Footings -Cantilever or Strap Footings -Cantilever and Combined Footings -Continuous Footings
-Concrete Masonry Foundation
Foundation Walls
Walls -Wood Joists -Wood Beams
Spread Footings
-Open-Web Steel Joists
Week 03 Concrete Slab on Grade
Foundation Systems
Pile Foundation
Pole Foundations Shallow Foundation
Deep Foundation Caisson Foundation
STRUCTURAL ELEMENTS
In the studio task, we observed the structure of different kinds
The design of a structural element is based on the loads to be carried, the material used and the
of architecture in university. The incredible underground
form and shape chosen for the element. The elements from which a structure is made or
parking left a deep impression to me. It is totally supported by
assembled have, in engineering or building terms, specific names which are used for convenience.
columns which are made of concrete and there is not any
Strut: a slender element design to carry load parallel to its long axis. The load produces
other structural elements like beams or steel in the roof of the
compression.
parking. How could this come true?
Tie: a slender element design to carry load parallel to its long axis. The load produces tension.
Firstly, they planted trees on the square in order of rows and
( such as cable ties in the bridge )
columns which is right over the parking, and then built a
Beam: Generally a horizontal element designed to carry vertical load using its bending resistance.
concrete column with about 1-meter hight and 0.6-meter
Slab/Plate: a wide horizontal element designed to carry vertical load in bending usually supported
diameter right under each tree.
by beams.
To make the columns uniformed, the constructor built
Panel: a deep vertical element designed to carry vertical or horizontal load.
funnel-type steel models with the same size. Finally they used perfusion method to put concrete in these models and then connected them with the columns on the ground. This is a creative approach because the trees make the constructure of the roof be tightly and those columns not just support the roof but also transfer the load of trees to the ground. The problem is that the concrete structure is easy to be infiltrated buy water especially under the ground. So it is necessary to fix the rifts timely and regularly.
Foundation are found at the bottom of buildings where the building meets the ground. The
Shallow Foundation: Shallow or spread foundation are
foundation are the SUBSTRUCTURE of the building and their function is to safely transfer all
employed when stable soil of adequate bearing capacity
loads acting on the building structure to the ground. Where parts of the substructure are located
occurs relatively near the ground surface. They are placed
below the ground, the foundations must also resist the force of the soil pressing against the
directly below the lowest part of a substructure and transfer
foundation (or retaining) walls.
building loads directly to the supporting soil by vertical
Differential settlement--the relative movement of different parts of a structure caused by
pressure.
uneven consolidation of the foundation soil--can cause a building to shift out of plumb and
Deep Foundation: Deep foundation are employed when the
cracks to occur in its foundation, structure, or finishes. If extreme, differential settlement can
soil underlying a foundation is unstable soil to transfer
result in the failure of the structural integrity of a building.
building loads to a more appropriate bearing stratum of rock
Retaining Walls & Foundation Walls: are used when sites are excavated to create basements or
or dense sands and gravels well below the superstructure.
where changes in site levels need to be stabilised. The pressure load of the earth behind the wall
Types of Shallow Footings
needs to be considered to present the wall from overturning.
Pad Footings: Also called isolated footing, these type of footings help to spread a point load over a wider area of ground. Strip Footings: used when loads from a wall or a series of columns is spread in a linear manner. Raft Foundation: Sometimes also called a raft slab, this type of foundation provides increased stability by joining the individual strips together as a single mat.
During the visit we can see the materials such as stone and brick which is used to build the
A brick is a standard size masonry unit made out of clay.
buildings especially those architectures with long history. We call this Mass Material includes stone,
Its proportions may vary slightly depending on types and
earth, clay and concrete. These materials are the group which are strong in compression but weak in
countries but it will always be a hand sized unit. Bricks
tension.
can be arranged in various ways to create different bond
Masonry Definition: Masonry refers to building with units of various natural or manufactured
patterns.
products, such as brick, stone, or concrete block, usually with the use of mortar as a bonding agent.
A concrete block is a standard size masonry unit made out
Bond: the patten or arrangement of the units
Course: a horizontal raw of masonry units
concrete. There is a large of sizes and proportions
Joint: the way units are connected to each other
Mortar: mixture of cement or line, sand and
available in order to suit different purposes.
water used as a bonding agent
Clay Bricks - Joints
Masonry Properties: The properties of the unit (par-) are to a degree applicable to the built
Mortar joints are usually 10 mm (vertical joints are called
element(whole).
perpends and horizontal joints are called bed joints). There are a range of joint finishing profiles which are selected depending on the type of brick, weather exposure and aesthetics. The properties of these mass materials contain the hardness,
fragility,
ductility,
flexibility/plasticity,
porosity/permeability, density, conductivity, durability/life span, reusability/ footprint and cost.
recyclability, sustainability & carbon
There is a steel bridge in front of the union house and when we look at it, we always think those
EQUILIBRIUM & FREE BODY DIAGRAMS
cables are the main force to support the whole but actually they are just used for decoration. The
Objects or systems in equilibrium can be represented in
steel tanks under the bridge really hold it with the joints by melting them together. Here we used
diagrammatic form called free body diagrams. In these
Structural Concepts / geometry & equilibrium.
diagrams, the real life appearance of elements is replaced
Equilibrium is a state of balance or rest resulting from the equal action of opposing forces. In other
by a combination of simple lines with symbols showing
words, as each structural element is loaded, its supporting elements must react with equal but
the types of structural connections used (roller, pin and fi
opposite forces. For an object to be in equilibrium, any applied forces must be resisted by equal and
xed joints). The applied forces (F) and reaction forces (R)
opposite forces. These forces are called reaction forces. In a building structure, the reaction forces
are represented by arrows (e.g. ê and ñ). These diagrams
are developed in the supporting elements.
allow the system to be analyzed so that the amount of
The center of mass is the point about which an object is balanced. It can also be thought of as the
load distributed to each support can be determined.
point where the entire weight of the object is concentrated. The location of the center of mass
EQUILIBRIUM = OBJECT or SYSTEM AT REST
depends on the object’s geometry. This concept is also sometimes referred to as Centre of Gravity.
This means that the sum of the applied and reaction forces must be zero in order for equilibrium to exist. If the object or system is not moving up or down (side to side/rotating),
then
the
sum
of
the
vertical
(horizontal/moments) forces must be equal to zero. ∑ V/H/M = 0
Knowledge Map (Week 04) Wood Joists Wood Joist Framing Wood Subflooring Prefabricated Joist & Trusses Wood Beams Wood Beam Supports Wood Post-Beam Connections Wood Plank-and-Beam Framing Wood Decking
Structural Steel Framing Steel Beam Connections -Moment Connections -Shear Connections
Wood
Week 04 Floor Systems
-Semi-Rigid Connections
Open-Web Joist Framing Metal Decking -Form Decking -Composite Decking -Cellular Decking
Concrete
Concrete Slabs
Concrete Beams
Steel
Light-Gause Steel Joist Framing
Precast Concrete Units
- One-Way Slab
- Solid Flat Slab
- One-Way Joist Slab
- Hollow Flat Slabs
- Two-Way Slab and Beam
- Single Tees
- Two-Way Slab and Beam
- Double Tees
- Two-Way Waffle Slab
- Rectangular Beams
- Two-Way Flat Plate
- L-Shaped Beams
- Two-Way Flat Slab
- ASSHTO Girders
Precast Concrete Connections
-Precast Slabs -Precast Structural Tees -Precast Beams
Scale, Annotations and Working Drawing Conventions
This is how the window and door are identified and they
During the studio, we used the drawing set to know about the structure of buildings. This is quite
can be find under the LEGEND G.A PLANS.
different way from what we observed on the campus. It dilates the building into the scale such as 1:20 on an A3 paper in plane form or three-dimensional. Actually, the use of different ratios of scales are depend on the size of the real constructure. The images with big scales contain less whole vision but more details of the building while the small scales are on the contrary. So the pictures of the whole vision of the structure inside or outside usually use the small scale. Except the scales we can also see some annotations labored on the paper. There is a TITLE BLOCK at the bottom of the each page which includes the consultants, key plan, client and project, description and date of revision, drawing title and drawing number. These basically shows the situation and description of the pictures above it.
The cloud shaped drawing is called revision cloud and that means there is a place needed to be corrected because of issues.
This is a grid and usually number and letter are used to identify
the
grid
lines. This is a kind of reference
to
other
drawings and it means there is a bigger size of
picture
contains
more details behind.
This is the way of floor levels noted on the plan.
SPAN Span is the distance measured between two structural supports.
BEAMS
Span can be measured between vertical supports (for a horizontal member) or between
A beam is a (mostly) horizontal structural element.
horizontal supports (for a vertical member).
The function of a beam is to carry loads along the length of
Span is not necessarily the same as the length of a member.
the beam and transfer these loads to the vertical supports.
SPACING
A beam can be:
Spacing is the repeating distance between a series of like or similar elements.
- supported at both ends of the beam
Spacing is often associated with supporting elements (such as beams, columns etc.) and can be
- supported at numerous points along the length of beam
measured horizontally or vertically.
- supported at points away from the ends of the beam
Spacing is is generally measured center-line to center-line.
(creating overhangs / cantilevers beyond the supports)
SPAN and SPACING
- supported at only one end of the beam (these beams are
Spacing of the supporting elements depends on the spanning capabilities of the supported
called cantilevers)
elements.
CANTILEVERS A cantilever is created when a structural element is supported at only one end (or the overhanging portions of a member are significant). The function of a cantilever is to carry loads along the length of the member and transfer these loads to the support. A cantilever can be: horizontal, vertical, angled
Wood joist floors are an essential subsystem of wood light-frame construction. The dimension
Structural steel girders, beams , and columns are used to
lumber used for joist is easily worked and can be quickly assembled an site with simple tools.
construct a skeleton frame for structures ranging in size from
Together with wood panel sheathing or subflooring, the wood joists from a level working
one-story buildings to skyscrapers. Because structural steel is
platform for construction. If properly engineered, the resulting floor structure can serve as a
difficult to work on-site it is normally cut, shaped, and
structural diaphragm to transfer lateral loads to shear walls; consult the building code for
drilled
specific requirements.
specifications; this can result in relatively fast, precise
- Because wood light framing is combustible, it must rely on finish flooring and ceiling
construction of a structural frame. Structural steel may be
materials for its fire-resistance rating.
left exposed in unprotected noncombustible construction, but
- The susceptibility of wood light framing to decay and insect infestation requires positive site
because steel can lose strength rapidly in a fire, fire-rated
drainage,adequate separation from the ground, appropriate use of pressure-treated lumber, and
assemblies or coatings are required to qualify as fire-resistive
ventilation to control condensation in enclosed spaces.
constructions. Connections usually use transitional elements,
Wood joists may be supported by wood or steal beams. Joist and beam hangers, post bases and
such as steel angles, tees, or plates. The actual connections
caps, framing angles and anchors, and floor ties and holddowns are used as connections of
may be riveted but are more often bolted or welded.
wood-to-wood, wood-to-metal, and wood-to-masonry.
Metal decking is corrugated to increase its stiffness and
in
a
fabrication
shop
according
to
design
spanning capability. The floor decking serves as a working platform during construction and ad formwork for a sitecast concrete slab.
FLOOR SYSTEM
Concrete Systems:
Floor system are the horizontal planes that must support both live loads and dead loads. Floor
Slabs of various are used to span between structural supports.
systems must transfer their loads horizontally across space to either beams and columns or to
These can be one-way or two-way spans.
bear walls. Rigid floor planes can also be designed to serve as horizontal diagrams that act as
Steel Systems:
thin, wide beams in transferring lateral forces to shear walls.
Steel framing systems take various forms, with some heavy
A floor system may be composed of a series of linear beams and joints overlaid with a plane
gauge structural steel members and others using light gauge
of sheathing or decking, or consist of a nearly homogeneous slab of reinforced to the size and
steel framing. In many instances a combination of member
proportion of the structural bays it must span and the strength of the materials used. The size
types and materials are combined (e.g. Heavy and light
and placement of any cantilevers and openings within the floor plane should also be
members) depending on their structural function.
considered to supporting foundation and wall systems affect both the structural integrity of a
Steel framing systems sometimes combine with concrete slab
building and its physical appearance.
systems to where the particular benefits of steel framing and shallow depth floor slab systems are desired. The spanning capabilities of the spacing requirements of the supports. Timber Systems: Traditional timber floor framing systems use a combination of bearers (primary beams) and joints (secondary beams). The span of the bearers determines the spacing of the piers or stumps and spacing of the bearers equals the span of the joints.
Knowledge Map (Week 05) -
Light-Gause
Concrete Columns
Stud
Framing
Week 05
- Balloon Framing
Framing
- Platform Framing
Short Columns
WALL SYSTEMS
- Wood Stud Framing
Concrete
- Stud Wall Sheathing -Wood
Structural
Concrete Walls Concrete Formwork
Post-and-Beam
Framing -
Long Columns
Masonry
Steel
Concrete Surfacing
Framing Masonry Bonding Masonry Lintels
Masonry Walls
Precast Concrete Walls
Masonry Arches Precast Concrete Connections
Masonry Terminology
Mortar Joints
Unreinforced Masonry Walls
Reinforced Masonry Walls
SHORT AND LONG COLUMNS
LONG COLUMNS
COLUMNS are vertical structural members designed to transfer axial compressive
Columns are considered LONG if the ratio of effective column
loads.
length to the smallest cross section dimension is greater than 12:1.
ALL columns are considered SLENDER MEMBERS and for axial loads, they can be
(For example: a 6000mm tall column with a 450mm x 300mm
classified as either the SHORT or LONG.
cross-section will have a ratio of 20:1.) Therefore it would be
SHORT COLUMNS are shorter (length) and thicker (cross-section).
considered a long column.
LONG COLUMNS are taller (length) and slimmer (cross-section).
LONG COLUMNS become unstable and fail by BUCKLING. The
SHORT COLUMNS
shape of the column cross-section determines the direction of the
Columns are considered SHORT if the ratio of effective column length to the smallest
buckling. The actual length of LONG COLUMNS and how they are
cross section dimension is less than 12:1. (For example: a 3000mm tall column with a
fixed at the top and bottom of the columns determines how they will
450mm x 300mm cross-section will have a ratio of 10:1.) Therefore it would be
buckle and how much load the column can carry.
considered a short column. SHORT COLUMNS will be structurally adequate if the
The EFFECTIVE length of the column is changed because of the
load applied to the column cross section does not exceed the compressive strength of
different fixing methods. The effective length is measured between
the material.
the points of CONTRAFLEXURE.
Compressive Strength (Pa) = Load (N) / area (mm2) SHORT COLUMNS become shorter when a compressive load is applied and then fail by CRUSHING (shear)when the compressive strength is exceeded (either by applying too great a load or if the cross-section is too small).
WALL SYSTEMS
- Solid Masonry load bearing walls can be created with single or
LOAD BEARING WALLS:
multiple skins of concrete masonry units or clay bricks.
- Concrete load bearing walls can be achieved using either in suit or precast elements. The load bearing PANELS may also provide support for SPANDREL PANELS over and
The skin of masonry are joined together using a brick (with HEADER showing in face of wall) or with metal WALL TIES
link into other structural elements (such as floor slabs, roof structure etc.)
placed within the mortar bed.
- Reinforced Masonry load bearing walls can be constructed from CORE FILED hollow
- Cavity Masonry walls are typically formed from two skins of
concrete blocks or GROUT FILLED masonry.
masonry.
BOND BEAMS over openings can be created using special concrete blocks which are
Advantages of this construction solution include: better thermal
filled with concrete to bond the individual units together. After the concrete has cured, the
performance and opportunities for insulation within the cavity,
temporary propping can be removed, leaving only the appearance of the concrete block
better waterproofing (ability to drain water from the cavity) and
wall. Bond beams are used as an alternative to steel or concrete LINTELS.
the opportunity to run services within the wall cavity.
Concrete and masonry walls qualify as noncombustible construction and rely on their mass for their mass for their load-carrying capability.
The presence of a DAMP PROOF COURSE and WEEP HOLES in a wall are indicators that the wall is a cavity wall rather than a solid wall. Height-to-width ratio, provisions for lateral stability, and proper placement of expansion joints are critical factors in wall design and construction.
WALL SYSTEMS
STUD FRAMING:
STRUCRURAL FRAMES:
Metal and Timber Stud Framing walls use smaller sections of
- Concrete Frames typically use a GRID of columns with concrete beams connecting the
FRAMING TIMBER or LIGHT GAUGE FRAMING STEEL to
columns together.
meet the structural demands of the construction.
- Steel Frames typically use a GRID of steel columns connected to steel girders and beams.
The smaller sections mean that the structural members are
Noncombustible steel frames may utilize moment connections and require fireproofing to
repeated at smaller intervals and require restraining along their
quality as fire-resistive construction.
lengths with rows of NOGGINGS to prevent the long thin
- Timber Frames (Post and Beam) typically uses a grid of timber POSTS or POLES
members from BUCKING.
connected to timber beams.
Stud framing generally consists of top plate, bottom plates,
Bracing of members between bays or at the corners of post/beam junction is required to
vertical studs, noggings, cross bracing and ply bracing.
stabilize the structure.
Brick Veneer Construction
- Structural frames can support an accept a variety of nonbearing or curtain wall systems.
Combinations of 1 skin of non-structural masonry and 1 skin of structural frame wall are widely used in the construction industry. Cavities in the wall frame can accommodate thermal insulation, vapor retarders, and mechanical distribution and outlets of mechanicals and electrical services.
During the class, we used a variety of materials (cardboard, foam blocks, foam
So I am going to analyze the TIMBER structure which is widely used in
core, balsa, corrugated card, glue) construct a 1:20 scale model of the
buildings.
STRUCTURAL SYSTEM of our assigned part of the Oval Pavillion which is a
Engineering Timber-SOLID PRODUCT
part of its roof.
LVL - Laminated Veneer Lumber made from laminating thin sheets of
The pictures below showed the work of the model which was made by the
timber,most laminates with grain aligned to longitudinal direction, very deep
students in the last class. It was really perfect and well constructed.
and long sections possible, high strength Engineering Timber-SHEET PRODUCT PLYWOOD - made by gluing and pressing thin laminates together to form a sheet, grain in laminates in alternate directions strength in two directions, Use- Structural bracing/structural flooring/formworks/joinery
After we analyze the drawings of each section of the constructing, we were going to cut each beam and column by the scale. Than we made the plate of the roof first and than the trusses which support this roof. Actually, if we look at the reference on the drawing we will find that the the whole structure is constructed by timber, So I am goning to talk about the timber frame.
Engineering Timber-Other Manufactured Produces The rationale to the following set of products lies in their ability to use materials very efficiently and their ability to accommodate services within their depth I BEAMS-timber/LVL flanges, plywood/OSB webs lightweight, suitable for medium spans BOX BEAMS-timber/LVL flanges, two plywood/OSB webs suitable for larger spans,torsionally stiff, can use decorative plywood TIMBER FLANGED STEEL WEB JOISTS-lightweight, open webs give access for service webs by light tube, solid round, corrugated sheet
Knowledge Map (Week 06) - Structural Steel Roof Framing - Steel Rigid Frames
Flat Roofs
- Space Frames
Sloping Roofs
- Open-web Joist Framing - Metal Rood Decking
Reinforced Concrete Roof Slabs
Week 06
Concrete Precast Concrete Roof Slabs
Roof Systems
- Rafter Framing
Framing
路Gable Roofs 路Hip Roofs 路Gambrel Roofs 路Flat Roofs - Light-Gauge Roof Framing
Trusses
- Wood Rafter Framing - Wood Plank-and-Beam Framing
Steel Trusses
Wood Trusses
- Flat Trusses
- Warren Trusses
- Pratt Trusses
- Bowstring Trusses
- Howe Trusses
- Crescent Trusses
- Belgian Trusses
- Scissors Trusses
- Fink Trusses
ROOF SYSTEMS The roof system functions as the primary sheltering element for the interior spaces of a
- The slope usually leads to interior drains; perimeter scuppers may be used as overflow drains.
building. The form and slope of a roof must be compatible with the type of roofing-shingles,
- Flat roofs can efficiently cover a building of any horizontal
tiles, or a continuous membrane-used to shed rainwater and melting snow to a system of
dimension, and may be structured and designed to serve as an
drains, gutters, and downspouts. The construction of a roof should also control the passage of
outdoor space.
moisture vapor, the infiltration of air, and the flow of heat and solar radiation. And depending
Pitched and Sloping Roofs (Pitch: >3째)
on the type of construction required by the building code, the roof structure and assembly may
- The roof slope affects the choice of roofing material, the
have to resist the spread of fire.
requirements for underlayment and eave flashing, and design
ROOF SLOPES
wind loads.
Flat Roofs (Pitch: 1째-3째)
- Low-slope roofs require roll or continuous membrane roofing;
- Flat roof require a continuous membrane roofing material.
some shingles and sheet materials may be used on 3:12 pitches.
- The roof slope may be achieved by inclining the structural members or roof deck, or by
- Medium- and high-slope roofs may be covered with shingles,
tapering the layer of thermal insulation.
tiles, or sheet materials. - Slope roofs shed rainwater easily to eave gutters - The height and area of a sloping roof increase with its horizontal dimensions.
CONCRETE ROOFS:
TRUSSED ROOFS:
Are generally flat PLATES of reinforced concrete (or precast slabs with a topping of concrete).
TRUSS roof are framed roofs constructed from a series of
The top surface is sloped towards drainage points and the entire roof surface finished with
OPEN WEB type steel or timber elements.
applied waterproof membrane.
Trusses are manufactured from steel or timber components,
STRUCTURAL STEEL FRAMED ROOFS:
fixed together to form efficient elements able to span long
FLAT structural steel roofs consist of a combination of primary and secondary ROOF
distances.
BEAMS for heavier roof finishes such as metal deck/concrete; or ROOF BEAMS and
The shape (slope) and material of the structural elements is
PURLINS for lighter sheet metal roofing.
often determined by the roofing material selected and the
SLOPING structural steel roofs consist of ROOF BEAMS and PURLINS and lighter sheet
functional requirements of the roof.
metal roofing .
SPACE FRAMES:
POTAL FRAMES consist of a series of braced RIGID FRAMES (two columns and a beam)
Space Frames are 3D PLATE type structure that are long
with PURLINS for the roof and GIRTS for the walls. The walls and roof are usually finished
spanning in two directions.
with sheet metal).
Linear steel sections of various cross section types are welded, bolted or threaded together to form matric-like structures. A tiled roof should be constructed at pitches greater than 15. Steel is commonly used in the construction industry because it has good compressive and tensile properties, it can be formed into many different products.
LIGHT FRAMED ROOFS:
TRUSSES TYPES
GABLE ROOFS are characterised by a vertical, triangular section of wall at one or both ends
Flat Trusses, Pratt Trusses, Howe Trusses, Belgian Trusses,
of the roof.
Warren Trusses, Bowstring Trusses, Raised-chord Trusses,
The roof consists of COMMOM RAFTS, RIDGE BEAMS and CEILING JOISTS. Where the
Crescent Trusses, Scissors Trusses
roof overhangs the gable end wall OUTRIGGERS are used.
STEEL TRUSSES are generally fabricated by welding or
MATERIALS timber, cold-formed steel section (and also sometimes heavier steel (UB or PFC)
bolting structural angles and tees together to form the
for major beams).
triangulated framework. Because of the slenderness of these
HIP ROOFS are characterised by a vertical, triangular section of wall at one or both ends of
truss members, connections usually require the use of steel
the roof.
gusset plates. Heavier steel trusses may utilize wide-flange
The roof consists of COMMON RAFTERS, HIP RAFTERS, VALLEY RAFTERS, JACK
shapes and structural tubing.
RAFTERS, RIDGE BEAMS and CEILING JOISTS.
WOOD TRUSSES
MATERIAL timber, cold-formed steel sections.
In contrat, to mono planar trussed rafters, heavier wood trussed can be assembled by layering multiple members and joining them at the panel point with split-ring connectors. Thess wood trusses are capable of carrying greater loads than trussed rafters and spaced further apart. Consult a structural engineer for design, bracing, and anchorage requirements.
During the tutorial in this week, we had a presentation of the site view that we had done in the
There is a common point with the three site that is they used
last four weeks. The site view is group work but we should finish the report full size and
timber frame massively. Timber, this kind of light, cheap and
presentation individually. We identify, analyze and discuss the structural systems, components
wide used material is suitable for many king of buildings
and joint types employed, construction systems, processes and methods, materials and their
especially for individual living. Because of the frame
use, detailing strategies.
construction are timbers so the joists are common nails. The
To compare the three sites that we had visited, these construction fields all started with
beams they used is also timber called ‘Smart Joist’ and it can
basement except our group because it had finished the first floor. So I listened to the
be a whole piece of wood or trusses with steel which depended
introduction of the basements from the other groups and recorded carefully.
on what kind of plate they would like to use above.
The foundation of the two field have a similar structural that is they are all reinforced. The
Outside the fire-proof plate, they used bricks to build the
workers dig into the soil deeply and they put the reinforces on the flat ground as a net or grid.
masonry walls with bricks. Between each brick, the used
And then they cover the foundation by concrete-this kind of hard, stable and wide used
cements which is made of sand and lime to be the joints. The
material. They left the reinforced columns above the concrete plate and these columns would
masonry bonding here is called RUNNING BONDING,
be the main force to support this building.
commonly used for cavity and veneer walls, is composed of overlapping stretchers. It is a good opportunity for us to talk about what we observed on the construction filed and linked them to what we learned before. We started to analyze what we had seen instead of describing them.
Week 07 (No Studio Session) Summary of Chapter 7, Ching Book
Sheet Metal Roofing
Roof Flashing
A sheet metal roof is characterized by a strong visual pattern of interlocking seams and
-Masonry or Concrete Parapet
-Chimney Flashing
articulated ridges and roofs edges. The metal sheets may be of copper, zinc alloy,
-Stud-Framed Parapet
-Skylight
galvanized steel, or terne metal, a stainless steel plated with an alloy of tin and lead. To
-Low Parapet Wall
-Vertical Wall Flashing
avoid possible galvanic action in the presence of rain water, flashing , fastenings, and metal
-Metal Gravel Stop and Fascia
-Tall Pipe or Pole
accessories should be of the same metal as the roofing material. Other factors to consider
-Metal Copings
-Stack Flashing
in the use of metal roofing are the weathering characteristics and coefficient of expansion
-Metal Gravel Stop
-Vent Pipe
of the metal.
-Ridge Flashing-Concealed
Single-Ply Roofing Systems Single-ply membrane roofing may be applied in liquid or sheet form. Large domed, vaulted, or complex roof forms require that the roofing membrane be rolled or sprayed on in liquid form. Materials used for liquid-applied membranes include silicone, neoprene, butyl rubber, and polyurethane.
Flashing Roof Penetrations
Wall Flashing
-Ridge Flashing-Exposed
-Head Flashing
-Ridge Vent
-Sill Flashing
-Flat to Sloping Roof
-Base Course Flashing
-Flat to Sloping Roof
-Parapet Flashing
-Exposed Valley
-Spandrel Flashing
-Top of Shed -Eve Flashing
Roof Drainage The amount of rain or melting snow a roof and its drainage system must handle is a function of: 路The roof area leading to the roof drains or gutters 路The frequency and intensity of the rainfall for the region Flat roof should be pitched to roof drains that are located at the low points and that connect to the storm drain system of the building. Rainwater shed by sloping roofs should be caught by gutters along the eave to prevent ground erosion. Gutters empty into vertical downspouts or leaders that, in turn, discharge into a dry well or storm sewer system. In dry climates or for small roof areas with adequate overhangs, gutters may be omitted and a bed of gravel or a masonry strip set in the ground under the eave line. Gutter are typically of vinyl, galvanized steel, or aluminum, although copper, stainless steel, terne metal, and wood ones are also available. Aluminum gutters can be cold-formed on-sited in continuous runs without joints.
Joint Sealants To provide an effective seal against the passage of water and air, a joint sealant must be durable, resilient, and have both cohesive and adhesive strength. Sealants can be classified according to the amount of extension and compression they can withstand before failure. Thermal Insulation The primary purpose of thermal insulation is to control the flow or transfer of heat through the exterior assemblies of a building and thereby prevent excessive heat loss in cold seasons and hest gain in hot weather. This control can effectively reduce the amount of energy required by
heating
equipment
and to
colling maintain
conditions for human comfort in a building.
Knowledge Map (Week 08) -Window Frame -Rough Opening -Casing Trim -Building
Code
Requirements
Door Hinges
Window Elements
Door Locksets
Door Operation -Swinging -Bypass Sliding
-Sash and Glazing -ADA Accessibility
Windows
Guidelines
Week 08 DOORS & WINDOWS
Doors
-Surface Sliding -Pocket Sliding -Folding Door Designs
- Fixed
Window Operation
Door Hardware
- Casement
-Flush -Glass -Vision
- Awning & Hopper - Sliding
-Narrow Light
Glazing Systems
- Double-Hung
-Full-Louvered -Vision/Louvered
- Jalousie - Pivoting Face Glazing
Wet Glazing
Dry Glazing
Structural Gaskets
GLASS
GLAZING SYSTEMS
Components of Glass
Face Glazing
Formers- are the basic ingredient used to produce glass. Any chemical compound that can be melted and cooled into a glass is a FORMER. (Silica) Fluxes- help FORMERS to melt at lower and more practical temperatures. (Soda Ash/Potash/
Small glass panes may be set in a rabbeted frame, held
Lithium Carbonate)
Wet Glazing&Dry Glazing
Stabilizers- combine with Former&Fluxes to keep the finished glass from dissolving or crumbling. (Limestone/Alumina/Magnesia) Properties of Glass Conductivity: transmits heat and light but not electricity Porosity/Permeability: non-porous/waterproof Durability/Life Span:typically very durable Hardness:high Density:medium-high Ductility:very low Fragility: high Flexibility/Plasticity:very high in the two characteristics Reusability/Recyclability:very high Sustainability & Carbon Footprint:typically high Cost:expensive to product and transport
Lights more than 6sf(0.56 ㎥ ) in area, must be wet- or
in place with glazier’s points, and sealed with a beveled bead of putty or glazing compound.
dry-glazed. Structural Gaskets Structural gaskets are performed of synthetic rubber or other elastomeric material to secure a glass pane or unit in a window frame or opening. The gaskets are held in compression by forcing a keyed locking strip into a groove in the gasket. They require smooth contact surfaces and a frame or opening with exacting dimensional tolerances and true plane alignment. The glass must be supported on at least two sides by the frame or a supported gasket.
Deformation & Geometry & Moment of Inertia Deformation
Moment of Inertia
Resisting moment - an internal moment equal and opposite to a bending moment, generated by a force couple to maintain equilibrium of the section being considered. Bending stress - a combination of compressive and tension stresses developed at a cross section of a structural member to resist a transverse force, having a maximum value at the surface furthest from the neutral axis. Neutral axis - an imaginary line passing through the controlled of the cross section of a beam or other member subject to bending, along which no bending stresses occur. Geometry Section modulus is a geometric property of a cross section, defined as the moment of inertia of the section divided by the distance from the neutral axis to the most remote surface.
an area and the square of its distance from a coplanar axis of
Moment of inertia is the sum of the products of each elements of rotation. It is a geometric property that indicates how the cross-sectional area of a structural member is distributed and does not reflect the intrinsic physical properties of a material. Insulating Glass Insulating glass consists of two or more sheets of glass separated by a hermetically sealed air space to provide increased thermal insulation and restrict condensation. Glazed Curtain Walls Glazed curtain walls are exterior non-load-bearing walls consists of vision glass or opaque spandrel panels supported by metal framing. They may be categorized according to their method of assembly. (Stick Systems, Unit Systems, Unit-and-Mullion Systems, Column-Cover-and-Spandrel Systems)
Wood Flush Doors DOORS
Hollow Flush Doors
Door Operation
They are lightweight but have little inherent thermal or acoustic insulation value.
-Swinging
While intended primarily for interior use, they may be used for exterior doors if
-Bypass Sliding
bonded with waterproof adhesive.
-Surface Sliding
Solid Core Doors
-Pocket Sliding
Solid core doors are used primarily as exterior doors, but they may also be used
-Folding
wherever increased fire resistance, sound insulation, or dimensional stability is
Door Designs
desired.
-Flush -Glass
Sliding Glass Doors
-Vision
Sliding Glass Doors are available with wood, alumium, or steel frames.
-Narrow Light
Wood frames may be treated with preservative, primed for painting, or
-Full-Louvered
clad in a aluminum or vinyl. Metal frames are available in a variety of
-Vision/Louvered
finishes, with thermal breaks and integral windproof mounting fins. Overhead Doors Overhead doors are constructed of one or several leaves of wood, steel, aluminum, or fiberglass and open by swinging or rolling up to a position above the door opening. The door may be operated manually, or by a chain hoist or electric motor. Coiling Doors Coiling or rolling doors consists of horizontal, interlocking metal slats guides by a track on either side and open by coiling about an overhead drum at the head of the door opening. The door may be operated by a chain hoist or electric motor.
WINDOWS
Wood frames are thicker than aluminum or steal frames, but they
Aluminum Windows
are also more effective as thermal insulations. The frames are
Aluminum window frame are relatively low in cost, lightweight, and corrosion resistant,
usually of kiln-dried, clear, straight-grain wood, factory-treated
but because they are such efficient conductors of because they are such efficient
with a water-repellant preservative. The wood may be stained,
conductors of heat, synthetic rubber or plastic thermal breaks are required to interrupt the
painted, or primed for painting on site. To minimize the need for
flow of heat from the warm to the cool side if the frame. Aluminum frames may have
maintenance, the majority of wood frames are now clad with vinyl
anodized, baked enamel, or fluoropolymer resin finishes.
or bonded to acrylic-coated aluminum sections that require no
Steel Windows
painting.
Steel window frame and sash sections are manufactured from hot-rolled steel. Because steel is stronger than aluminum, these sections are more rigid and thinner in profile than
In this week tutorial, our task is to draw a part of Oval Pavilion on
aluminum sections, offer narrower in a given rough or masonry opening. Steel also has a
an A1 paper as the scale of 1:1. My part is the roof of this building
lower coefficient of heat transfer than aluminum and therefore steel window frames do not
so it is not easy to observe it at the real site but I can see a lot of
normally require thermal breaks.
materials has been used on this roof such as timber, glass, aluminum and so on. The picture below is the finished work of my drawing and some record form the outside.
Week 09 Site Visit
At week 09, I went for two site views and these is my main task so there was no tutorial for that Friday. The first site I went to was s construction field of an apartment with six levels
From the out side we can see that the building is
and this is what did it look like from outside.
supported by concrete walls and reinforces. The floor system here is precast concrete. They work as main bearing systems because this kind of high level structural needs stable and hard bracing so that timber can not be used here.
Firstly, we visit the workers’ office and see their daily record board. Our leader showed us their construction drawings. They are different from the drawing that we learned of Oval Pavilion in tutorial because they are more complexed with a lot modes and symbols. He told us these were sent here from architects and they should do just follow the drawings. Sometimes, these drawings is not just designed as the order of each floor or each room, it can even show each piece of material that that they use. Then he pick up a drawing and it really contain each panel that they used in this building, more than 1000 panels with details were drawn on it!
Metal decking is corrugated to increase its stiffness and spanning capacity. The floor deck serves as a working platform during construction and as formwork for a site cast concrete slab. 路The decking panels are secured with puddle-welds or shear studs welded through the decking to the supporting steel joists or beams. 路 The panels are fastened to each other along their sides with screws, welds, or button punching standing seams. 路If the deck is to serve as a structural diaphragm and transfer lateral loads to shear walls, its entire perimeter must be welded to steel supports. In addition, more stringent requirements for support and side lap fastening may apply.
Structural steel girders, beams , and columns are used to construct a skeleton frame for structures ranging in size from one-story buildings to skyscrapers. Because structural steel is difficult to work on-site it is normally cut, shaped, and drilled in a fabrication shop according to design specifications; this can result in relatively fast, precise construction of a structural frame. Structural steel may be left exposed in unprotected noncombustible construction, but because steel can lose strength rapidly in a fire, fire-rated assemblies or coatings are required to qualify as fire-resistive constructions. Connections usually use transitional elements, such as steel angles, tees, or plates. The actual connections may be riveted but are more often bolted or welded. Conventional steel-framed structures are constructed of hot-rolled beams and columns, open-web joists, and metal decking. Since structural steel is difficult to work on site, it is normally cut, shaped, and drilled in a fabrication shop according to design specifications; this can result in relatively fast, precise construction.
This is the bathroom of the building.
There are also some water pipes standing on the ground and they have been set in the building. Copper piping is commonly used for water supply lines because of its corrosion resistance, strength, low fiction loss, and small outside diameter. Plastic pipes are lightweight, easily joined, produce low friction, and do not corrode, but not all types are suitable for carrying potable water. PB, PE, PVC CPVC pipes may used for cold -water supply lines; only PB and CPVC are suitable for the hot-water lines. The
water
supply
system
can
usually
be
accommodated within floor and wall construction spaces without too much difficulty. It should be coordinate with the building structure and other systems, such as the parallel but bulkier sanitary drainage system. Water supply pipes should be support at every story vertically and every 6’ to 10’(1830 to 3050) horizontally. Adjusted hangers can be used to ensure proper pitch along horizontal runs for drainage.
Ventilation Bathroom require either natural or mechanical ventilation in order to remove stale air and supply fresh air. A mechanical ventilating system may be employed in lieu of natural ventilation. The ventilating fan should be located close to the shower and high on an exterior wall opposite the bathroom door. It should be connected directly to the outside and be capable of providing five air changes per hour. The point of discharge should be at least 3’ away from any opening that allows outside air to enter the building. Residential exhaust fans are often combined with a light fixture, a fan-forced heater, or a radiant heat lamp.
Let’s see what other materials were used in this room except the steel. As we can see, there are some wires with
The foreman introduced to us this kind of material is
different colors. Actually, each of them has it
called “fire- proof plate”. Actually, this kind of
own use such as the white wire is electric
material can bear burning from the fire for 40
wire and the red one is for smoke detector.
minutes. They don’t need to have this materials very
The purple one is the gas tube and the two
high quality because this is not a construction with
brown wires are for cold and hot water
many timber components.
respectively. The orange wire below is the
Electrical
internet cable.
Electrical switches and convenience outlets should be located where they are need but away from water or wet areas. They should not be accessible from a bathtub or shower.
The stairs of this building is made
We went down the stairs and get into the underground garage of this apartment,
of concrete. A concrete stair is
we can see a lot of familiar structures such as concrete and metal decking floor,
designed as an inclined, one-way
masonry block walls, concrete bearing walls and drainage systems. But the
reinforced slab with steps formed
columns here were never seen before because they are made of soil by press
on its upper surface. If the stair is
them with massive strength and they can bear tones weight.
constructed after the floor beam or wall supports, it acts as a simple beam. If it is cast with the beam or slab supports, it is designed as a continuous beam. Concrete stairs require careful analysis of load, span,
and
support
conditions;
consult a structural engineer for final design requirements.
This is the temporary elevator in the construction field. Elevators travel vertically to carry passengers, equipment, and freight from one level of a building to another. The two most common types are electric elevators and hydraulic elevators. Electric Elevators Electric elevator consist of a car that is mounted on guide rails, supported by hoisting cables, and driven by electric hoisting machinery in a penthouse. Geared traction elevators are capable of speeds up to 350fpm (1.75m/s) and are suitable for medium-rise buildings. Gearless traction elevators are available with speeds up to 1200fpm (6m/s) and typically serve high-rise buildings. Hydraulic Elevators consist of a car supported by a piston that is moved by or moves against a fluid under pressure. A penthouse is not required, but the hydraulic elevator’s lower speed and piston length limit its use to buildings up to six stories in height.
Knowledge Map (Week 10)
Size of exposed Structural. Minimum value at base, max. Heroes and culprits
at top.
Statue of liberty:
Wind Lateral Support Earthquake
Week 10
Corrosion
Galvanic corrosion, statue of liability was made of copper skin, copper turns to copper oxide which is green
Mass above foundation
Collapses and failure for
Max . at base of structure,
beach houses (Ashford,
minimum at top.
P.,2014)
Thin and white fascia exposed to sun,cracks
Interactive Structures
The water tower is a heavy structure with large inertia.
Lateral Forces
In an earthquake, the top portion of the structure barely
Resistance to lateral loads is a major design concern for buildings in many geographical location.
moves while the ground and its lower portion move
Lateral loads are mostly due to wind and earthquakes.
significantly. This puts extreme stress on the structure.
Although wind and earthquake forces are dynamic loads. In order to predict their effect and
However, because the water tower has relatively little
magnitude on structures and simplify the analysis procedure, they can generally be treated as static
surface area and considerable inertia. It is thus
loads for the purpose of preliminary design.
minimally affected by wind forces.
The billboard is a sight-weight structure that is minimally affected by earthquakes. This is due to its small inertia and its ability to move with the ground with minimal bending. However, because of its
Wind and earthquake forces have different effects on
large surface area, it is significantly affected by wind.
buildings. For example, wind forces are a function of the amount of building mass above the foundation. Wind forces act on the surface of a structure and have a minimum value at the base and
maximum value at the
highest elevation. Earthquake forces act at the base of a building structure and can abruptly reverse direction. These differences are critical in the engineering calculations that determine the magnitude and are articulated by various codes. However, in many cases, the type of resisting systems and techniques for providing stability and controlling lateral displacement are very similar.
Lateral Load Resisting Systems
Diaphragms and Lateral Bracing
Structures that respond properly to lateral forces must have resistive elements in both the
A braced horizontal surface can act as a diaphragm,
horizontal and vertical planes. The following are the basic system used for resisting lateral loads.
transferring lateral loads across the structure to braced
These system can be used solely or in combination to reduce the impact of lateral forces on a
walls or shear walls where they can be transmitted into
structure.
the ground.
Diaphragms
Shear Wall
Diaphragms are structural elements that resist and collect lateral forces in the horizontal planes of
A shear wall acts to stiffen a building against lateral
a structure and transfer them to the vertical bearing elements. Roofs and floor slabs that are
loads. A tall shear wall works like a cantilever beam out
constructed from rigid materials such as reinforced concrete or steel frames with sufficient bracing
of the ground and is loaded mainly in flexure. A short
are considered to be diaphragms.
shear wall resists overturning. In the building shown above, the lateral loads try to pivot the wall at the foundation, which would tend to lift it off the ground for most of its length. However, the mass of the wall resists this overturing moment by rotating it in the opposite direction.
Design Consideration for Wind Loads
Heroes and culprits
Wind loads can heavily influence the design of tall and narrow multistory buildings. When the
Issues: Health, waste, energy use, pollution, life cycle
height of a building is much greater than its least width, the wind load may result in drift and
Materials: building materials responsible for: 30% raw
lateral instability in the narrow direction of the building. Depending on the specific conditions of
material use, 42% energy use, 25% solid wastes, 40%
the building, any of the lateral resisting load system previously discussed can be used ti achieve
atmospheric emission
stability. Other conditions such as unusual shapes, structures with large openings, or buildings
Culprit->heroes:
with large cantilevers or projections also must be investigated for wind load impact.
·Oil-based paints -> water-based
Wind Loads
·Timber->bamboo (grows quickly)/recycled timber
A tall, thin ‘slab on end’ building is significantly affected by wind loads since it has little depths to
·Chemicals for termites->termimass
resist lateral loads and a large surface area facing the wind.
·Chemical cleaner->fibre cloth
Overhanging awning roof are vulnerable to wind since they tend to act like wings and flap in
·Timber joist->smart joist
strong winds.
·Aluminum-> recycled aluminum ·Hardwood(grow slower)->softwood ·Overseas product->local product · PVC flooring(plastic)->linoleum flooring (made from cork) Choose materials with high reusability and long life cycle (Hes, D., 2014)
This week’s tutorial, we brought our A1 drawing paper of Oval Pavilion to the class in order to do some presentation.
The part that I drew is the top of this building -roof and it is the angle of the roof so that I cannot observe it of the real building. However, as we can see from the drawings the roof contains quite different kinds of materials such as Thermal Insulation, Timber Wall Lining,
Skylight
Blinds,
Glazing,
Flashing, Acoustic Insulation, Aluminum Fascia and Sealant. Interlocking seams form a labyrinth that inhibits the passage of water. The Skylight blind is a glass-enclosed porch or room adjoining another living space and oriented to admit large amounts of sunlight. Sunspaces are often used in passive solar design in conjunction with a thermal mass of masonry, rock concrete to store the solar heat gain. The main task during the class is trying to draw a 3D image of the building by a slope of 45° on the track paper. The 1:1 drawing of the section is going to be traced on the tracing paper in order to create a 3D representation of the section.
Workshop
Today we did the Workshop as a group with 3 students and that was a quite great experience to learn
Span: The spanning capability of horizontal elements
the features of materials, to create a structure by ourselves and to get yo know how to use some basic
determines the spacing of their vertical supports. This
tools. The task is to construct a structure that will span 1000mm and will take a point load at its center.
fundamental relationship between the span and spacing defined
The maximum height is 400mm and the test is to see how much of a load our structure can take.
by the structural system of a building. The dimensions and
Firstly, the tutor introduced the tools that we could use during making it. We could use sundry nails
proportions of structural bays, in turn, should be related to the
and screws to assist with joining, and hammers, saws screwdrivers and marking tools to assist in the
programmatic requirements of the space. (Reference from
process.
Ching Book: Chapter 2.20 Structural Spans)
The materials were provided to us are: 1200 x 3.2 x 90mm Ply x 2 and 1200 x 42 x 18mm Pine x 2
Static load - Dead loads & Live loads Live loads comprise any moving or movable loads on a structure resulting from occupancy, collected snow and water, or moving equipment. A live load typically acts vertically downward but may horizontally as well to reflect the dynamic nature of a moving load. Dead loads are static loads acting vertically downward on a structure, comprising the self-weight of building elements, fixtures, and equipment permanently attached to it. (Reference from Ching Book: Chapter 2.08 Loads on Buildings)
Then we were going to design the structural we discussed the features of these two
Plywood
kinks of woods: Plywood and Pinewood. The plywood is thin and soft, so it must be
A typical plywood panel has face veneers of a higher grade than the core
good at tension but not compression. To compare with plywood, the pinewood is
veneers. The principal function of the core layers is to increase the
more hard and thick so it has much capability of compression but less tension. We
separation between the outer layers where the bending stresses are highest,
finally decided to cut three same size columns from pinewood and put them on the
thus increasing the panel's resistance to bending. As a result, thicker panels
span wood horizontally in the order of center and then two sides. Here the plywood
can span greater distances under the same loads. In bending, the maximum
worked for bracing and connected the span and columns as the picture shows below.
stress occurs in the outermost layers, one in tension, the other in
We used nails to get them tightly became together. After we finishing each side of the
compression. Bending stress decreases from the maximum at the face
plywood, the span ( 1000mm ) was put on the three columns and finally fixed on the
layers to nearly zero at the central layer. Shear stress, by contrast, is higher
columns by nails as well.
in the center of the panel, and zero at the outer fibers.
After we finished our structure, there was going to be a test of it. The tutor would keep
Plywood Siding
press on the center of span by a machine. We found that another group had a quite
Exterior-grade plywood siding panels are typically 4’×8’ (1220×2440),
different design from us because they use the Plywood to be the span and also the
although 9’ and 10’ (2.8and 3.0m) lengths are available. The most
pinewood is column but taller and more than ours. It just like the picture shows below
common pattern imitate vertical board siding. The panel surface may
and they have a quite different idea from us. As we can see from the picture, they use
have a grooved, rough-sawn, brushed, or striated texture, and may be
the plywood as the bottom and top because the think it has good quality of tension.
stained or treated with a clear water-repellant finish. Medium-density
They cut the pine wood into the same size and these are the colums bwtween the two
overlay (MDO) is an exterior plywood panel having a melamine or
pieces of plywood.
phenolic resin overlay on one or both sides, providing a smooth base for painting. Horizontal joints, which must be protected by flashing or other means, are very noticeable. These horizontal lines should therefore be coordinated with other exterior wall elements such as window and door openings.
After we finishing the structures, the tutor was going to test how strong are our works. He brought us to a machine which can force press on our wood. Firstly, we put another group’s work on the machine impending and gonna to test it. They use a Spiral leveraged with a ruler to push pressure on the middle of this structure. We can read the weight that we push and how long does it go down. From this two data we can know the compression and tension quality of the structure basically. With we keeping pressing we can easily see that the pine wood began to band. When the number on the ruler declined for 10cm, the screen showed that it had been bearing 200kg weight. At this time, we can hear the sound of broken and the nails at two sides had been come out. When we kept pressing, it did not band widely like the beginning and the sound of break is getting louder. Finally, the ruler went down for another 5cm and the structure could not bear any more and it broke at the middle totally and the two-side nails were pulled out completely. It could bear more than 300kg as maximum before breaking. However, our group did not have a appearance of this because it has a bad tension so when the pressure was more than 100kg, it just went down for 3cm. The pine wood at two sides began to band and we could hear the wood started to break. At 150kg, it broke totally and after we study the break section we found that we use too big nails on pinewood so it became easily to beak.
Reference List: In text reference : Reference from: Ching Book, Chapter 1.07, SITE ANALYSIS Reference from: Ching Book, Chapter 1.11, TOPOGRAPHY Reference from: Ching Book, Chapter 2.03, BUILDING SYSTEMS Reference from: Ching Book, Chapter 3.02, FOUNDATION SYSTEMS Reference from: Ching Book, Chapter 3.02, FOUNDATION WALLS Reference from: Ching Book, Chapter 5.37, STEEL COLUMNS Reference from: Ching Book, Chapter 3.16, COLUMN FOOTINGS Reference from: Week 01 E-Learning
INTRODUCTION TO MATERIALS
Reference from: Ching Book, Chapter 4.26, WOOD JOISTS Reference from: Ching Book, Chapter 4.33, PREFABRICATED JOISTS & TRUSSES Reference from: Ching Book, Chapter 2.07, TYPES OF CONSTRUTION Reference from: Ching Book, Chapter 2.17, FRAME &WALLS Reference from: Ching Book, Chapter 5.27, MASONRY BONDING Reference from: Ching Book, Chapter 11.32, ELECTRICALCIRCUITS Reference from: Ching Book, Chapter 4.05, CONCRETE SLABS Reference from: Ching Book, Chapter 11.24, WATER SUPPLY SYSTEMS Newton, C. (2014). A Tale of Corrosion. Retrieved from http://www.youtube.com/watch?v=2IqhvAeDjlg&feature=youtu.be Newton, C. (2014). Basic Structural Forces. Retrieved from https://app.lms.unimelb.edu.au/bbcswebdav/courses/ENVS10003_2014_SM1/WEEK%2001/Basic%20Structural%20Forces%201.pdf Newton, C. (2014). Composite Materials. Retrieved from http://www.youtube.com/watch?v=Uem1_fBpjVQ&feature=youtu.be Newton, C. (2014). Concrete. Retrieved from http://www.youtube.com/watch?v=c1M19C25MLU&feature=youtu.be Newton, C. (2014). Construction Detailing. Retrieved from http://www.youtube.com/watch?v=yqVwAV7yJCI&feature=youtu.be Newton, C. (2014). Detailing For Heat and Moisture. Retrieved from http://www.youtube.com/watch?v=Lhwm8m5R_Co&feature=youtu.be
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