Sem 3 Building Construction II Assignment 1: Skeletal Structure by Esther Wong

B U I L D I N G

SH E LT E R

DR. SUJATAVANI GUNASAGARAN

DAREN L AI KAM FEI TEOH CHONG KIN YONG PING PING

0332570 0331215 0332585

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ESTHER WONG JIA EN 0332188 WENDY L AU JIA YEE 0333538

B L D 6 0 7 0 3

TUTOR

B U S

I I

T EM PO RARY

C O N S T R U C T I O N

SKELETAL CONSTRUCTION

O F

C O N T E N T S

T A B L E

INTRODUCTION PAGE 01-02

O F

C O N T E N T S

CONSTRUCTION PROCESS

RENDERINGS

PAGE 35-36

PAGE 13-18

DESIGN CONSIDERATIONS PAGE 03-04

DESIGN DEVELOPMENT

CONSTRUCTION DETAILS

CONCLUSION

PAGE 37-38

PAGE 19-26

D E S I G N A N A LY S I S PAGE 27-32

REFERENCES

PAGE 39-40

TA B L E

PAGE 05-06

ORTHOGRAPHIC DRAWINGS PAGE 07-12

LOAD BEARING TEST PAGE 33-34

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I N T R O D U C T I O N

01 I N T R O D U C T I O N

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I N T R O D U C T I O N

INTRODUCTION A bus shelter is known as a designated place where buses stop for passengers to board or alight from a bus. It is a structure constructed to provide seating and protection from the weather for the convenience of waiting passengers. In a group of 5, we are required to construct a temporary bus shelter to accomodate 5-6 people on a scale of 1:5 with a maximum base of 400mm x 800mm and maximum height of 600mm. To ensure the structure is built for its practicality, the main focus of this project is to learn and understand the construction of skeletal frames and joints, later synthesizing the knowledge into the bus shelter design. In order to show our understanding of the skeletal structure, we are required to define all building components such as roof, columns, beams, walls and floor. To begin with, we are to choose combination of any two forms for the bus shelter. After discussion, we decided to choose the triangular prism and cuboid forms to start our bus shelter design.

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D E S I G N

C O N S I D E R A T I O N S

02 D E S I G N C O N S I D E R AT I O N S 0 3

D E S I G N

DESIGN

CONSIDERATIONS

C O N S I D E R A T I O N S

ANTHROPOMETRICS & ERGONOMICS

WEATHER RESISTANCE

The bus shelter should be able to provide sufficient space for maximum capacity of users. It also has to be built according to the human anthropometrics and ergonomics for human comfort and convenience.

The bus shelter should be able to withstand local climate. The design should accommodate to the hot direct tropical sun and heavy rainfall to provide protection for the users.

SAFETY

MATERIALIT Y

STABILIT Y

The bus shelter must have suitable openness to provide visibility to see traffic conditions. Stability and maintenance of structure is taken into consideration for usersâ&#x20AC;&#x2122; safety.

Chosen materials need to provide high strength and durability, readily available and eco-friendly.

The structure of shelter should be able to resist both horizontal and lateral forces such as wind, live load and dead load.

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D E S I G N

D E V E L O P M E N T

03 D E S I G N D E V E L O P M E N T 0 5

D E S I G N

Design of the temporary bus shelter is initiated from the massing comprising of a combination of a triangular prism and cuboid stacked on top of each other.

Additional columns are designed to provide extra roof support. A column (highlighted in red) is added in between the existing two. Another middle row of columns (highlighted in yellow) is added, also as framework for the seating area.

D E V E L O P M E N T

From the massing, we derive its skeletal frame structure and determine the basic structural elements which are columns, beams, floor and roof. The roof is designed to be a pitched roof to allow rainwater discharge.

Seating platform is designed to be built in and sit on vertical plates which are placed in the gap between the middle and back row of columns.

Roof is cantilevered and extended outwards to provide more shading and protection from direct tropical sunlight and rain.

Vertical timber strips are added in between middle and back row of columns as partition screens. The seating platform is also designed as horizontal timber strips, creating a visual similarity with the vertical timber screens.

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O R T H O G R A P H I C

D R A W I N G S

04 O R T H O G R A P H I C D R AW I N G S 0 7

D R A W I N G S

400

1200

800

2050

150

400

550

300

150

400

O R T H O G R A P H I C

3450

400

FLOOR PLAN Scale 1:25

1250

125

150

125

10 0

200

10 0

FOUNDATION PL AN Scale 1:25

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D R A W I N G S

2082 53 9

3113

492

O R T H O G R A P H I C

2225

4450

ROOF PLAN Scale 1:25

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D R A W I N G S

540

220

45 0

3590

2104

576

O R T H O G R A P H I C

498

3454

498

3113

R OOF P I TCH 10

4450

F R O N T E L E VAT I O N Scale 1:25

R I G H T E L E VAT I O N Scale 1:25

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D R A W I N G S

5 40

220

450

3590

2104

576

O R T H O G R A P H I C

498

3454

498

3113

R OOF P I TCH 10

4450

B AC K E L E VAT I O N Scale 1:25

L E F T E L E VAT I O N Scale 1:25

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O R T H O G R A P H I C

D R A W I N G S

PERSPECTIVE NTS

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C O N S T R U C T I O N

P R O C E S S

05 C O N S T R U C T I O N P R O C E S S 1 3

C O N S T R U C T I O N

P R O C E S S

PREPARATION 1. Timber are cut to size and sanded to smoothen the surface by removing any rough edges using 150 grit sandpaper. 2. This is to increase and strengthen the area of contact between two connecting elements. 3. A layer of shellac is coated on the structures to provide extra protection against weather after sanding.

PRE-CONSTRUCTION 1. 2.

A physical model of scale 1: 20 is produced. Detailed drawings with accurate scaled measurement is produced using Sketchup. 1 4

C O N S T R U C T I O N

P R O C E S S

FOUNDATION 1. Wooden blocks are used to represent concrete pad footings in the actual scale model. 2. The wooden blocks are cut into size and later sprayed with colour adhesive paint to represent the materiality of concrete. 3. The blocks are allowed to dry thoroughly, representing the concrete curing process. It is then ready to be installed as pad footings for the bus shelter.

FLOOR SYSTEM 1. Each floor beam is connected to each other by using L brackets which is then fixed into place by self-tapping screws. 2. This forms the base framework for installation of columns and timber floor panels.

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C O N S T R U C T I O N

P R O C E S S

COLUMN 1. L brackets are used to connect the columns to the floor beams, providing a strong bonded structure.

TIMBER FLOORING 1. Timber plank is measured and sawed into smaller panels to be used as flooring.

2. Rectangular timber blocks are then inserted and installed between columns, after which timber strips are installed onto these blocks as partition screen elements.

2. Holes for the columns are measured then cut out from the panels before installing them onto the base framework. 3. A layer of shellac is applied onto the panels as well for protection against the elements.

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C O N S T R U C T I O N

P R O C E S S

SEATING 1. Long timber strips spanning the whole width of the bus shelter are horizontally placed onto the timber blocks and carefully arranged between the columns. 2 It is then nailed into place, creating the seating platform for users.

ROOF SYSTEM 1. Roof rafters and purlins are attached together by birdsmouth joint. 2. The rafters are also directly connected to the columns for extra support.

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C O N S T R U C T I O N

P R O C E S S

POLYCARBONATE ROOF 1. The polycarbonate sheet is cut according to dimension that fits and can provide cover to the whole structure. 2. It is then fixed onto the roof system, supported by rafters.

FINAL PRODUCT 1.

The superstructure is then fixed onto the pad footings, hence completing the temporary bus shelter scale model.

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C O N S T R U C T I O N

D E T A I L S

06 C O N S T R U C T I O N D E TA I L S 1 9

C O N S T R U C T I O N

D E T A I L S

PAD FOOTING

6.1

CONCRETE FOOTING

Dimensions Width : 400mm Length : 400mm Height : 500mm Material : Reinforced concrete

FOOTING

DETAILS AND CONNECTIONS 132

Pad footing is used as the foundation of bus shelter as the superstructure of the bus shelter are relatively low, thus it is still managed to withstand loads and forces distributed onto the bus shelter and provides optimum stability.

COLUMN STUMP

200

COLUMN SHOE

ANCHOR BOLT

Materiality : Aluminium

Dimensions Width : 200mm Length : 200mm Height : 132mm

Dimensions Length : 150mm Anchor bolt diameter : 14mm Nut diameter : 18mm

CONCRETE PAD FOOTING SECTIONAL DETAIL

150

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TIMBER BEAMS / COLUMNS AND CONCRETE CONNECTION

COLUMN SHOE

COLUMN STUMP

FOOTING

Bearing plates are required to transfer concentrated compressive force between the timber and concrete structure.

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C O N S T R U C T I O N

D E T A I L S

FLOOR BEAM

DETAILS AND CONNECTIONS L BRACKET

SELF TAPPING SCREW

Materiality : Steel

Dimensions Thickness : 2mm Length : 15mm Height : 30mm

Dimensions Length Head diameter Shank diameter

Skeletal structure of the bus stop is consist of vertical timber columns and horizontal timber beams constructed in a rectangular grid. The columns and beams are connected via L brackets which holded by self tapping screw. Self tapping screws are used due to its convenience for maintenance work.

SECONDARY BEAMS

TIMBER BASE FRAMEWORK

Dimensions Width : 150mm Length : 200mm Material : Merbau

6.2

PRIMARY BEAMS

: 44mm : 13mm : 7mm

BUT T JOINT DETAIL

The two timber beams are attached together perpendicularly using wood glue and is screwed to provide extra support.

BEAM TO BEAM CONNECTION

The primary beam act as the main horizontal support, transfer the load from secondary beam to the columns and to the pad footing.

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C O N S T R U C T I O N

D E T A I L S

TIMBER FLOORING

The panels are placed on the beams to provide support for users to step on. The panels are precisely measured and cut to fit the base structure.

DETAILS AND CONNECTIONS FLOOR PANEL

IRON NAIL

Materiality : Merbau

Materiality : Steel

Dimensions Width : 450mm Length : 2050mm Height : 20mm

Dimensions Length Head diameter Shank diameter

Flooring used in bus shelter is made up of eight plywood panels, representing merbau, which are durable and able to resist uniform loads perpendicular to the surface. Flooring panels are attached to the floor beams via iron nails along the floor joist.

6.3

Dimensions Width : 2050mm Length : 3450mm Height : 20mm Material : Merbau

: 40mm : 5mm : 2mm

FLOOR TO BEAM CONNECTION Iron nails are used to secure panels to the floor beams tightly to avoid any detachment while in use.

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C O N S T R U C T I O N

D E T A I L S

COLUMN

Column B : 20x15mm

Material

(To connect roof framing to the concrete pad footing)

(Secure the seating strips and provide aesthetic purpose)

: Merbau

DETAILS AND CONNECTIONS L BRACKET

SELF TAPPING SCREW

Materiality : Steel

Dimensions Thickness : 2mm Length : 15mm Height : 30mm

Dimensions Length Head diameter Shank diameter

Vertical timber column is part of the skeletal system. The bus shelter requires vertical timber columns to support the overall roof structure design. The loads carried are then directly transfer to the pad footing and to the ground.

Column C : 150x20mm

TIMBER COLUMNS

COLUMN C

Dimensions Column A : 150x150mm

6.4

COLUMN B

COLUMN A

: 44mm : 13mm : 7mm

MORTISE AND TENON JOINT

Connection between column C and seating support

COLUMN TO BEAM CONNECTION

L brackets are used to provide extra support to the joints

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C O N S T R U C T I O N

D E T A I L S

SEATING BENCH

SEATING AREA

Consist by 6 timber strips which functioned as benches for users to provide comfort and allow ventilation from below. Benches are supported by wood panels below it and are secured by iron nails. Timber strips are placed perpendicular to the columns and timber panels.

DETAILS AND CONNECTIONS

Timber strips functioning as benches for users, supported by wood blocks below it.

TIMBER STRIP

TIMBER BLOCK

Materiality : Merbau

Dimensions Width : 70mm Length : 3450mm Height : 50mm

Dimensions Width : 125mm Length : 550mm Heigth : 397mm

Placed under seating area to act as support for timber strips.

SEATING TO COLUMN CONNECTION

IRON NAIL Materiality : Steel Dimensions Length Head diameter Shank diameter

: 40mm : 5mm : 2mm

6.5

Dimensions Width : 550mm Length : 3450mm Height : 450mm Material : Merbau

Mortise and tenon joints holding timber block to column.

Iron nails are used at the edges of the seating to secure the timber strips to the timber panels

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C O N S T R U C T I O N

D E T A I L S

ROOF SYSTEM

6.6

ROOF SYSTEM Timber roof rafter is pitched for shed roof. Different thickness of columns and joists are fixed via half lap joint. Extra support is provided by locking with anchor bolts. Purlins and rafters are attached together by birdsmouth joint to give extra support.

Dimensions Width : 2400mm Length : 3650mm Pitch : 10ยบ Material : Merbau

DETAILS AND CONNECTIONS TIMBER RAFTER

TIMBER PURLIN

Materiality : Merbau

Dimensions Width : 150mm Length : 2400mm Thickness : 50mm

Dimensions Width : 150mm Length : 3650mm Thickness : 50mm

ANCHOR BOLT

ROOF SYSTEM CONNECTION

Materiality : Aluminium Dimensions Length : 150mm Anchor bolt diameter : 14mm Nut diameter : 18mm

150

14 18

HALF LAP JOINT

BIRDSMOUTH JOINT

Half lap joints holding column and ceiling joist together.

Half lap joints holding column and ceiling joist together. 2 5

C O N S T R U C T I O N

D E T A I L S

ROOFING

6.7

POLYCARBONATE

Dimensions Width : 3113mm Length : 4450mm Material : Polycabonate

ROOFING DETAILS AND CONNECTIONS FIXING BUTTONS

WOOD SCREW

Materiality : Plastic

Materiality : Steel

Dimensions Diameter : 10mm

Dimensions Length : 25mm Diameter : 3mm

Reduce the risk of roofing sheet being dislodged.

The excellent properties of polycarbonate panels make them the preferred material for building greenhouses. These panels are resistant to heat, sunlight, snow, and rain, which enable them to last for many years without fading or discolouring.

P O LYC A R B O N AT E S H E E T TO T I M B E R RAFTER CONNECTION Polycarbonate roof is tightened in place by fixing buttons which secures the sheet onto the roof rafters

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D E S I G N

A N A L Y S I S

07 D E S I G N

A N A LY S I S

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D E S I G N

7.1

A N A L Y S I S

HORIZONTAL AND VERTICAL MEMBERS

HORIZONTAL MEMBERS

VERTICAL MEMBERS

Roof beam, roof joist, floor beam and floor joist act as horizontal members of the structure, bearing the loads which are perpendicular to its length. Beams are primarily used to carry horizontal loads. The loads carried by the beams are transferred to the columns, which is subsequently transferred to the ground level.

Timber columns and timber posts act as vertical support members of structure, sustaining its own weight and loads that are withstanding the compressive force. Each of the vertical structures help to transfer loads and forces all the way from the roof of bus shelter to the foundation.

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D E S I G N

7.2

A N A L Y S I S

LOAD AND FORCES

LOAD SYSTEM: T W O WAY S L A B S Y S T E M - The loads are carried by the beams along both directions. - The ratio of longer span to shorter span is less than 2. Calculation : ratio = 3400/2000 = 1.7 (<2 )

LOAD SYSTEM: EXTERNAL FORCES 1. Dead loads - A permanent force acting on the structure including the weight of structure itself. - The dead loads are constant throughout the body of the structure. 2. Live loads - Movable and non-permanent loads like pedestrian, wind and rainwater add different intensity of loads onto the structure. D E AT H LOA D

L I V E LOA D

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D E S I G N

7.3

A N A L Y S I S

DESIGN STRATEGIES

SUNLIGHT

VENTIL ATION

The polycarbonate roof can resist high temperatures. Its semi transparenciness reduces direct sunlight penetration and provides thermal comfort. Overhangs on both front and back aids in sun shading.

Vertical columns allow wind to flow in and out of the structure. Its openness helps reduce resistance against strong winds and lateral forces horizontally. Absence of walls maximises ventilation as well.

HUMIDITY

RAIN

ACCESSIBILITY

The structure is slightly elevated from ground to prevent ground moisture having direct contact with the timber structure. Merbau wood is chosen as flooring material due to its durability. It does not shrink much when in contact with moisture.

The slanted roof is adjusted to an appropriate angle to prevent accumulation of rainwater on the roof and to ensure efficient rainwater drainage.

The openness of bus shelter creates ease of accessibility to as there are multiple entrances to the structure. People are able to access the bus shelter through the front and both sides of it.

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D E S I G N

7.4

A N A L Y S I S

MATERIALIT Y

P O LYC A R B O N AT E Used as roofing material.

Pros : As it is easy to install, durable and practical. It is also waterproof and lightweight thus able to withstand extremely low and high temperatures. It provides thermal comfort to users as it can block out UV rays efficiently. Visually aesthetic and giving a modernic ambience. From a environment protection perspective, it has lower carbon emission rate than other materials.

MERBAU

Used as columns, floor slab, beams and joists. Pros : Merbau is known to be strongly durable and resistant to rotting and insects. It is a good heat insulator while also renewable and readily available. Strong merbau wood is ideally suited for structural columns and flooring as strength is the main consideration in the design.

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D E S I G N

7.4

A N A L Y S I S

MATERIALIT Y

STEEL

Used as material for column shoe. Pros : Column shoes provide fast and safe connections as it can be adjusted and installed easily. It has good resistance under high load condition and immediately loadable once installed.

CONCRETE

Used as pad footing for foundation Pros : Concrete has good load bearing capacity to resist the structural weight with its high compressive strength. It also allows flexibility of size based on the load it carries.

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L O A D

B E A R I N G

T E S T

08 L O A D B E A R I N G T E S T 3 3

L O A D

B E A R I N G

T E S T

TIMBER FLOORING

P O LYC A R B O N AT E R O O F

SEATING BENCH

Test subject : Textbooks (3kg each) Unit :2 Total load : 6kg Representation : Live loads imposed onto the flooring

Test subject : Textbooks (3kg each) Unit :2 Total load : 6kg Representation : Live loads imposed onto the roof

Test subject : Textbooks (3kg each) Unit :2 Total load : 6kg Representation : Live loads imposed onto the seating bench

Test Result : Successful. The timber flooring is able to withstand the loads imposed onto the strcuture.

Test Result : Successful. The roof is able to withstand the loads imposed onto the structure.

Test Result : Successful. The bench is able to bear the loads imposed onto the structure.

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R E N D E R I N G S

09 R E N D E R I N G S

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R E N D E R I N G S

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C O N C L U S I O N

10 C O N C L U S I O N

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C O N C L U S I O N

CONCLUSION This project allowed us to experience firsthand the design and construction process of building a practical and fully functional bus shelter, which emphasizes the understanding and practical application of skeletal frame construction and use of joints. It first started with choosing an appropriate combination of forms, in this case a cuboid and triangular prism, which serves as a firm and stable massing for the bus shelter. Moreover, there is the consideration of using timber as our main skeletal frame construction material and how to the use of polycarbonate and concrete into different parts of the design, while taking note of each of their individual characteristics that contributes to the strength and durability of the bus shelter. We also experimented with different types of joints to ensure that the joints used are able to effectively connect two individual elements together while able to withstand considerable compressive strength. Furthermore, we also acquired the necessary knowledge and techniques to assemble the joints together carefully and precisely for efficient load transfer. In conclusion, we learnt how essential every step and detail is in producing the final outcome, including the understanding of loads and forces, materiality, environmental factors, relationship between construction elements and more.

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R E F E R E N C E S

11 R E F E R E N C E S

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R E F E R E N C E S

REFERENCES Books 1. Chudley, R. 1987. Construction technology. Harlow: Longman. 2. Chudley, R. 2006. Construction Technology. 4th edition. Pearson and Prentice Hall. 3. Lyons, Arthur. 2004. A. Materials for Architects and Builders. 2nd Edition. Oxford. Elsevier Butterwort-Heinemann. 4. Seeley, Ivor H. 1995. Building Technology. 5th edition. Basingstoke, Hants: MacMillan. 5. Ching, Francis D.K. 1991. Building Construction Illustrated. New York. Van Nostrand Reinhold. 6. Simmon, H. Leslie. 2001. Construction: Principles, Materials and Method. 7th Edition. New York. John Wiley & Sons. 7. Zannos, Alexander. 1987. Form and Structure in Architecture: The Role of Statistical Function. Von Nostrand Reinhold Company, New York. Websites 1. Vermont Timber Works. Joints Used in Timber Framing. Retrieved from: https://www.vermonttimberworks.com/blog/traditional-joints-used-in-timber-framing/ 2. Bearing Joints. Timber Joints. February 27, 2013. Retrieved from: https://www.slideshare.net/Dipesh8585/joints-16805206 3. WoodWorkers Guild of America.Woodworking Joints: Which Wood Joints Should You Use?. August 29, 2018. Retrieved from: https://www.wwgoa.com/article/woodworking-joints-which-ones-should-you-use/ 4. Roof. Pitched Roof Construction. Retrieved from: https://myrooff.com/pitched-roof-construction/ 5. The Advantages and Disadvantages of Polycarbonate Roofing. May 26, 2015. Retrieved from: http://www.morganasphalte.co.uk/news/the-advantages-and-disadvantages-of-polycarbonate-roofing/ 6. Great Home. A Guide To Roof Construction-Part 1. September 20, 2016. Retrieved from: http://great-home.co.uk/a-guide-to-roof-construction/

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