PROJECT 1: Structural Design Post Mortem by Chevally Lo

Structural Design and Analysis Proposal for

VISITOR INTERPRETIVE CENTRE Valley of Hope, Sungai Buloh.

Project 1: Structural Design Post Mortem Building Structures (BLD61003) School of Architecture, Building and Design

Group Members: Phua vey suanne || 0327864 Chevally Lo Zhao Shyen || 0326497 Looi Kye Meng || 0327703 Woo Kar Hui || 0326656 Khoo Chee Keat || 0327433

Tutor: Mohamed Rizal Mohamed

Content 1.0

Introduction to the VIC and its Structural System

1.1

Orthographic Drawings of The Existing VIC

4 - 12

1.2

Appraisal on The Existing Structural Design

2.0

1.2.1

Safety

13 - 15

1.2.2

Economy

15 - 16

1.2.3

Optimization

1.2.4

Stability

1.2.5

Strength

18 - 19

1.2.6

Rigidity

19 - 20

Modified Orthographic and Structural Drawings 2.1

3.0

21 - 30

Modification 2.1.1

Foundation

2.1.2

Ground Floor Structural System

32 - 33

2.1.3

Columns

2.1.4

Steel Beams

2.1.5

Steel Open Web Joist System

36 - 37

2.1.5.1

First Floor Structural System

2.1.5.2

Roof Structural System

2.1.6

First Floor Slab Modification

2.1.7

Building Material (Timber)

39 - 40

Load Distribution 3.1 Roof Structure Load Distribution

3.2 First Floor Load Distribution

3.3 Ground Floor Distribution

3.4 Vertical Load Distribution

4.0

Conclusion

5.0

Reference

1.0 Introduction to the VIC and its Structural System The Bonhomie Visitor Interpretive Centre The Bonhomie visitor interpretive centre exposes the visitors to different definitions of happiness felt by the lepers despite the disease and the discrimination by the society. It functions to reminisce the olden days experienced by the lepers’ community, form a close-knit community between the visitors and the locals, as well as allowing the visitors to experience the act of happiness. The design intention of the VIC is “open-plan” with lightweight construction in order to suit the design concept. The majority of the structural system of this VIC is the use of SHS columns and timber floorings with no considerations of the types, sizes, locations, and the existence of foundation, beams, and the slab systems. Consequently, appraisals of the existing structure are discussed to be improved.

Roof

First Floor

Ground Floor

1.1 Orthographic Drawings of The Existing VIC

Ground Floor Plan 1:150 5

1.1 Orthographic Drawings of The Existing VIC

First Floor Plan 1:150 6

2.0 Modified Orthographic and Structural Drawings A

Roof Plan 1:150 7

South Elevation 1:150

East Elevation 1:150 10

Section A 1:150 12

1.2 Appraisal on The Existing Structural Design 1.2.1 Safety Issue #1: The size of the columns (100mm x 100mm SHS) is insufficient to support such height of the building (8165mm).

South Elevation (Existing)

Possible result : Fail to support the load of the building, which might result in the deformation and collapse of the whole building.

Issue #2 : Absence of structural members to transfer the load from the slab to beams, columns, and foundation.

Section A (Existing)

Possible result : Floor might collapse due to overloading of the existing load bearing capacity. (Refer to UBBL 59(6)- All beams shall be designed to carry the distributed load appropriate to uses to which they are put.)

1.2 Appraisal on The Existing Structural Design Issue #3: Proper type of foundation was not considered.

Section A (Existing)

Possible result : Building will crack and sink unevenly, or, the stability of the whole structural frame will cause the building to collapse.

Issue #4: Cantilevered area (2300mm) on first floor have exceeded the standard requirement with no support from the columns and beams.

First Floor Plan (Existing)

Possible result : Cantilevered area will collapsed. (Refer to UBBL 29- Balcony projections with roofs or awning not exceeding 1.8 metres in depth from the external wall of the main building within the building line area may be allowed. The sides of the balcony may be walled-up, provided that the walled-up area shall not be more than 60% of the total area of the vertical plans of the projections.)

1.2 Appraisal on The Existing Structural Design Issue #5: Timber flooring on the ground floor is in contact with the ground without proper coatings.

Section A (Existing)

Possible result : Wood decking might decay and weather. (Refer to UBBL 80(2)- Where structural timber floors are permissible under these Bylaws they shall be designed of hardwood or of species of timber treated with a suitable wood preservative.)

1.2.2 Economy Issue #1: Lack of beams.

Ground Floor Structural Plan (Existing)

Possible result : Lack of beams which leads to the result of insufficient support to the slab and roof, which need more column to maintain the stability which will cost more.

1.2 Appraisal on The Existing Structural Design Issue #2: Lack of beams on the first floor.

Section A (Existing)

Possible result : Thicker floor deckings, which will cost more, are needed to support the floor decking to prevent the building from collapsing.

Issue #3: Using pinewood as floor decking.

Section A (Existing)

Possible result : Pinewood, as a softwood, can be damaged more easily and requires extensive treatments in order to prevent rot. The need of this long term maintenance is not economical as it will cost more.

1.2 Appraisal on The Existing Structural Design 1.2.3 Optimization Issue #1: Litracon (Light Emitting Concrete) cylindrical walls on the first floor are mainly for aesthetic purposes with no aid to the structural system of the building.

First Floor Plan (Existing)

Possible result : Increase in dead load and narrowing width of walkways.

Issue #2: Columns on the first floor reaching up to the roof.

East Elevation (Existing)

Possible result : The spatial organisation and circulation of the users will be limited by the improper arrangement of columns. 17

1.2 Appraisal on The Existing Structural Design 1.2.4 Strength Issue #1: Using pinewood as wood decking.

First Floor Plan (Existing)

Possible result : Strength of softwood will decrease if not treated carefully as it has a lower strength and higher tendency to be prone to movement compared to hardwood.

1.2.5 Stability Issue #1: Absence of structural system of the balcony for support.

East Elevation (Existing)

Possible result : The balcony of the building will be unstable and is prone to collapsing.

1.2 Appraisal on The Existing Structural Design 1.2.6 Rigidity Issue #1: Lack of foundation.

Section A (Existing)

Possible results : The building might sink unevenly and deformation of the building might occur as there are no footings to act as a â&#x20AC;&#x153;footholdâ&#x20AC;? on the earth to keep the building intact and support the weight of the building. Issues #2: The size of the columns (100mm x 100mm SHS) is insufficient to support such height of the building (8165mm).

Structural Plan (Existing)

Possible results : Load carried by the column exceeds the load bearing capability of the structural system.

1.2 Appraisal on The Existing Structural Design Issue #3 : Lack of beams in the structural system.

Structural Plan (Existing)

Possible results : The columns might not withstand the lateral forces acting on it, which will result in the deformation of the building. (Refer to UBBL 59(6)- All beams shall be designed to carry the distributed load appropriate to uses to which they are put).

2.0 Modified Orthographic and Structural Drawings

Ground Floor Plan 1:150 21

2.0 Modified Orthographic and Structural Drawings

First Floor Plan 1:150 22

2.0 Modified Orthographic and Structural Drawings

Roof Plan 1:150 23

South Elevation 1:150

East Elevation 1:150 26

2.0 Modified Orthographic and Structural Drawings

Section A 1:150 27

2.0 Modified Orthographic and Structural Drawings

GB1 C1

GB2 GB1 C1

GB2

GB2 GB1 C1

GB2 GB1 C2

GB2

GB1

GB1 C2

GB2 GB1 C2

GB2

GB1 C1

GB2 GB1 C2

GB1

GB2

GB1

- Ground Beam - Column

GB1

GB2

GB1

C2(203x203)

GB1

GB2

GB1

GB2

GB1

GB2

GB1

GB C

GB2

GB2(500x350)

GB2

C1(203X203)

GB1

GB2

GB1(500X350)

GB1 C1

Ground Floor Structural Plan 1:150 28

2.0 Modified Orthographic and Structural Drawings

FB1 C2

C2(203x203)

FB2(152x152)

OWSJ 1 (8644)

OWSJ 2 (4270)

OWSJ 1 OWSJ 1

OWSJ 2

OWSJ 1

OWSJ 2

FB1

OWSJ 2 OWSJ 2

FB1

OWSJ 2

OWSJ 2 FB2

OWSJ 2

FB2

OWSJ 2 FB2

OWSJ 1

FB2

C1(203X203)

FB1

OWSJ 2

FB2

FB1(152x152)

OWSJ 2

OWSJ 2 C1

FB1 OWSJ 3

OWSJ 2

FB1

(17390)

FB2

OWSJ 3 FB2

OWSJ 3 OWSJ 3 OWSJ 3 C2

FB1

FB2

FB1

FB2

FB1

FB - Floor Beam C - Column OWSJ - Open Steel Web Joist

First Floor Structural Plan 1:150 29

2.0 Modified Orthographic and Structural Drawings

FB1(152x152)

C1(203X203)

FB1 OWSJ 4 (13016)

FB1

FB2(152x152)

OWSJ 4 OWSJ 4 OWSJ 4 OWSJ 4 C1

FB1

FB2

OWSJ 1

OWSJ 2 (4270) OWSJ 2

OWSJ 1

FB2

OWSJ 1

HD1

HD1 (3800)

OWSJ 1 (8644)

OWSJ 2 OWSJ 3

(17390)

OWSJ 3 C1

OWSJ 3 OWSJ 3

FB2

OWSJ 3 OWSJ 3 OWSJ 3

C1 OWSJ 3 OWSJ 3 FB2

FB2

OWSJ 3 OWSJ 3 OWSJ 3

OWSJ 3 OWSJ 3

FB2

OWSJ 3 OWSJ 3 OWSJ 3 OWSJ 3

FB C OWSJ HJ

FB1

- Floor Beam - Column - Open Steel Web Joist - Header Joist

FB1

Reflected Roof Structural Plan 1:150 30

2.1 Modification 2.1.1 Foundation Foundation is the substructure supports that helps to transfers the loads to earth and prevent the movement of the structural system. Foundation Type

Piling

Pad Foundation

Building Type

Usually use to support heavy load building such as : High rise building

Usually use for residential buildings

Soil Condition

Applied on soft soil condition

Applied on firm soil condition

Excavation

Deeper excavation and higher material consumption

Less excavation and material needed

Cost & Time

Higher Cost and longer time of period of construction

Lower cost and shorter period time of construction

Pad foundation is selected as the foundation for the building as it is sufficient to support the building at such height. Also, the dead load of superstructure is not heavy. Types : Square footing Dimension: 700mm x 700mm x 300mm

Pad Foundation

500 300

700 Ground Floor Structural Plan

700 Pad Footing

Pad footing can enhance the rigidity and stability of the building as the foundation acts as the anchor of the building. By comparing with other foundation types, pad footing is more economic as it costs lesser, does not require long construction period, lesser excavation and materials needed for the construction. Hence, it is more suitable for the building. 31

2.1 Modification 2.1.2 Ground Floor Structural System Slab To provide flat surfaces in building floors. It may be supported by walls, beams, columns or ground. In Situ Concrete Slab Type

One-Way Slab

Two-Way Slab

Building Type

Usually used in ratio of longer span to shorten span is greater than two : Low rise building

Usually used in low rise and high rise building

Strength

Supported on two opposite sides

Supported on all four sides

Structural Action

Works in one direction

Works in both direction

Two-way slab construction is used due to its stability as it supports by beams and columns on all four sides. It distribute loads through all the beams instead of two beams only. Type : Two-Way Slab Dimension : 3873mm x 4600mm Depth : 101.6 mm (min.)

Two-way slab

Ground Floor Structural Plan

2.1 Modification 2.1.2 Ground Floor Structural System

Steel Column

Timber flooring

Cast in R.C. slab

Pad Footing

Ground Beam

Two-way slab is chosen due to its high strength and durability as the building material used is reinforced concrete. The load bearing for ground floor slab is larger than that of first floor level and roof level, which the structural action is one of the main factor to be considered.

Type : R.C. Beam Dimension : 500mm x 350mm Length (Ground Beam 1) : 3873mm Length (Ground Beam 2) : 4600mm

Ground Floor Structural Plan

2.1 Modification 2.1.3 Columns Type

Hollow Steel Sections (HSS)

H-Column

Rigidity

Higher flexibility, easier to customize

Harder to change shape due to its section

Load Capacity

Lower strength, normally used for aesthetic purposes

Higher strength due to the thickness of the center web

Cost

Lowest cost among all types of vertical structural members

Higher cost compared to other types of vertical member due to its weight

H-column are used as the rigidity and strength of it is the highest among the vertical structural members which the columns needs to support most of the load. It is also economic due it needs lesser maintenance.

Type : H-column Dimension: 203mm x 203mm Height (Column 1) : 8165mm Height (Column 2) : 5035mm

203 203

First Floor Structural Plan

1/2

H - Column Ground Floor Structural Plan

2.1 Modification 2.1.4 Steel Beams Type

H-Beam

I-Beam

Connection

Strong in connecting bolts and other components due to its widened flat flange

Weaker in connecting bolts and other components due to the inclined flange

Strength

Good at withstanding stresses including torsional stress

Good at withstanding tensile and compressive stress, but weak at torsional stress

Direction of Force

Can withstand two directions of forces

Can only bear force from one direction

H-beam is chosen as it has higher lateral stiffness and bending resistance, which increases its materiality strength. It is also lighter and cheaper than I-beam under same specifications due to it have a better section mechanical properties than I-beam.

Type : H-beam Dimension : 152mm x 152mm Length (Floor Beam 1) : 5092mm Length (Floor Beam 2) : 4169mm

First Floor Structural Plan

1/2

152 152

H - Beam Reflected Roof Structural Plan

2.1 Modification 2.1.5 Steel Open Web Joist System 2.1.5.1 First Floor Structural System Type

Steel Beam

Open Web Steel Joist (OWSJ)

Building Type

Usually used to support heavy load building such as : High rise building

Usually used for residential buildings

Load Capacity

Higher load capacity

Lower load capacity

Cost

Higher cost and longer period of construction

Lower cost due to its lightweight properties.

Open web joist system is selected due to its economical aspect as the cost is lower and the period of time to install the system is shorter compared to other types of structural members. The lightweight properties of the system is beneficial as it will not produce too much dead load to the columns and foundation system. Although the load capacity of OWSJ is lower compared to steel beam, the lightweight of the timber decking results in the inconsideration of load capacity.

Type: K-Series open-web steel joist Dimension: Spacing of joist: 830mm Bearing length: 65mm

First Floor Structural Plan

Depends

17220 220

K - Series open-web steel joist Reflected Roof Structural Plan

2.1 Modification 2.1.5 Steel Open Web Joist System 2.1.5.2 Roof Structural System Type : Header Joist Thickness : 132.4mm

Reflected Roof Structural Plan

3800

132.4

Header Joist

Header Joist is used for the opening of the roof open web steel joist system. Its function is to create another pathway for load distribution while maintaining the strength and the rigidity of the roof structural system.

2.1 Modification 2.1.6 First Floor Slab Modification Modification #1 : All the timber slabs are aligned to the structural members to ensure the stability of the building and safety of the users.

Existing Modified First Floor Plan (Modified)

Modification #2 : The location of the balcony is moved to be aligned with the grid system of the building to provide support and stability to the balcony, as well as to minimise the cantilevered area.

Existing Modified First Floor Plan (Modified)

Modification #3 : Staircase of the building is aligned to the grid system to lay on the beam of the building to optimize the stability and the rigidity of the staircase.

Modification Beam First Floor Plan (Modified)

2.1.7 Building Material: Timber Timber is utilized in the construction industry in Malaysia. It is economical as it can be installed efficiently, save time, labour and cost without having the need to rent heavy equipment for installation. Timber has high load-bearing capacity (strength), treated with waterproofing, termite-proof that which permits it to be qualified as structural outdoor materials since it can withstand high level of dead load, dynamic load, rainwater and insects. The choice of type of timber is listed below: 1.

Engineered Wood Flooring:

●

Made up of layers where the top layer is 100% natural wood, which comes in variety of species. The natural wood lays on top of 5 - 7 layers of high quality plywood crisscrossing in different directions. The highly stable core is engineered to shift, expand, or contract when exposed to humidity, moisture and temperature.

●

2. ● ●

Solid Hardwood Flooring: Known for its authenticity, timeless and durability. Constructed of 100% hardwood.

Engineered Wood Flooring

Solid Hardwood Flooring

Thickness, width

Typically between 3-7mm, thicknesses of up to 15mm are available with plank sizes starting at 127mm wide.

Thickness typically is 20mm. Plank width begins at 127mm and can go up to 280mm wide.

Pre-finished / site-finished

Mostly pre-finished.

Installation

Have greater range of installation methods that are easier than that of solid hardwood flooring: 1) Nail-down floor, 2) Glue-down floor, 3) Floating floor

Lower range of installation methods, usually nailed or stapled down.

Durability

Durable, as it holds up moisture, temperature, and humidity. Its plywood base is dimensionally stable, when contact with moisture than solid hardwood, but can become de-laminated and if stressed beyond normal condition as it’s layer of wood is thin.

Durable if well laminated. Not designed to hold up excessive moisture. Site-finished hardwood flooring has a sealed top layer to resist some moisture.

Cost

Tends to be less expensive than solid hardwood flooring.

2.1.7 Building Material: Timber Proposal on the type of timber flooring : Acacia Engineered Wood Flooring

Acacia Wood Flooring

Engineered wood flooring with a thickness of 16mm is chosen because due to its ability to reduce moisture problems associated with conventional hardwood. This increases the strength of the timber itself, hence indirectly improves the safety measure of the structural system. Engineered wood flooring is economical as it is less expensive than most hardwood, will not warp, hence decreasing its needs of maintenance. Acacia, also named as Big Leaf Acacia or Malaysian Acacia, is originated from Malaysia. Due to its good quality and beauty, it is preferred by the market. Acacia wood has a Janka rating hardness of 1100lb -1790lb, which offers a high average Janka rating. Its ability to resist decay makes it durable, if untreated without any coatings, it can last up to 40 years.

3.0 Load Distribution 3.1 Roof Structure Load Distribution

Reflected Roof Structural Plan

1. Adding open web steel joist system as the supporting to the roof, which helps the hold the corrugated steel roof covering. At the same time, it helps to enhance the strength of the roof structure by transferring the live load (rain and wind) to the lower level through the columns.

3.0 Load Distribution 3.2 First Floor Load Distribution

First Floor Structural Plan

2. Open Web Steel joists act as secondary beams, which transfer the live load and dead load from the floor to the primary beams (H Section Beam). By installing the beam system on the first floor, the amount of columns can be decreased, which helps to decrease the cost of the building in contrast with the rigidity of the building. The H Column will transfer the load from the roof and beam to the ground level.

3.0 Load Distribution 3.3 Ground Floor Load Distribution

Ground Floor Structural Plan

3. After adding foundation and ground beams, the load distribution of the building are more completed. The ground beams can impart lateral stability and transfer the force horizontally at the same time. Pad footings help to transfer the load from the superstructure to the supporting soil and hold the position of the column.

3.0 Load Distribution 3.4 Vertical Load Distribution

Section A

After modification, the load distribution of the building is completed. Open steel web joist system transfers the load from the building to the vertical support, the columns then transfer the load to the earth through the the foundation. Good load distribution system can increase the durability of the whole structural system.

4.0 Conclusion As an overall conclusion, we are able to identify the suitability of the existing structural design. The main issues for the structure are safety, economy, optimization, strength, stability and rigidity. Safety issues that had been brought up is the inappropriate size of the columns, lack of structural support, unsuitable type of foundation, the overextended cantilevered area and coating for timber flooring was not consider properly in the design. Moreover, economy issues are insufficient beams and using of expensive material for the floor deck. In addition, another important issue is optimization which cylindrical walls was design and improper arrangement of columns. Further, as for the strength and stability the main problem is by choosing the inaccurate material and lack of structural support system. We also know that this design is lacking of foundation and beams.

The modifications made were based on the issues addressed. Foundation that suitable for this structure is pad foundation. As for the ground floor structural system we proposed to have in situ concrete slab and ground beam. The proposed columns and beams that we chose is H-column and H-Beam. Steel open web joist system is used for the first floor structural system and roof structural system. Floor slab modification is also one of the crucial part of this structure.

Main purpose of the modifications are to enhance safety, economy by decreasing the cost and period of construction, optimization by fully utilising the capability of the structural members, strength by using stronger and harder building materials, stability and rigidity of the structural support system. Throughout this report, we understand that every parts of the structure should be taken into consideration as part of the design scheme.

5.0 Reference Foundation in construction - Wikiversity. (2018). Retrieved from https://en.wikiversity.org/wiki/Foundation_in_construction Designing a Concrete Pad Foundation. (2018). Retrieved from https://www.istructe.org/getattachment/98c7f9ac-499b-4857-9dae-15096ba485c5/TGN7-2.pdf Types of Foundations in Building Construction. (2018). Retrieved from http://www.understandconstruction.com/types-of-foundations.html Pile Foundations | Types of Piles | Cassions. (2018). Retrieved from http://www.understandconstruction.com/pile-foundations.html What is Pad Foundation? Design Principles,Types and Selection. (2018). Retrieved from https://theconstructor.org/geotechnical/pad-foundation-design-principles-types-selection/7514/ Universal Beams - Rainham Steel. (2018). Retrieved from http://www.rainhamsteel.co.uk/products/universal-beams Rc II two_way_slabs. (2016). Retrieved from https://www.slideshare.net/Khawwam/rc-ii-twowayslabs Engineerâ&#x20AC;&#x2122;s Notebook(2018). Retrieved from https://www.structuremag.org/wp-content/uploads/2014/08/C-EngrNotebook-Antiquated9a-Stuart -June-091.pdf Francis D.K Ching- Building Construction Illustrated (2014). Building construction illustrated. New Jersey: John Wiley & Sons Inc. Guidelines for two-way concrete system | BSBG | Brewer Smith Brewer Group. (2018). Retrieved from https://bsbgltd.com/blog/guidelines-for-two-way-concrete-flooring-system/ Timber for Construction in Malaysia | Building Material Malaysia | Buy and Sell with us | Aathaworld Sdn Bhd. Retrieved from https://www.aathaworld.com/single-post/TimberSupplierMalaysia See How Engineered Flooring Is Better Than Solid Hardwood. Retrieved from https://www.thespruce.com/pros-of-engineered-wood-flooring-1821641 Deciding Between Hardwood and Laminate Flooring: Which Is Better? - coswick.com. Retrieved from https://www.coswick.com/blog/deciding-between-hardwood-and-laminate-flooring-which-is-better /