bconreport

BACHELOR OF SCIENCE (HONS) IN ARCHITECTURE

GROUP MEMBERS:CLARA LEE PEI LIN 0324495

JOY ANN LIM EE HSIEN 0327592ERIC LO YANN SHIN 0324922

YUEN XUAN HUI 0324292LEE JIA MIN 0324126

TUTOR: MR EDWIN

BUILDING CONSTRUCTION II (BLD 60703)PROJECT 1: SKELETAL CONSTRUCTION (TEMPORARY BUS SHELTER)

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CONTENTS1.0 Introduction

3.0 Orthographic Drawings

6.3 Loads and Forces

6.2 Timber Skeletal Frame Construction

9.0 Reference

2.0 Design Considerations

4.0 Construction Process

6.4 Materiality

2.1 Design Development

5.0 Construction Details

6.5 Load Test

2.2 Final Design

7.0 Renderings

6.0 Design Analysis

8.0 Conclusion

1.0INTRODUCTION

A bus shelter is known as a designated place where bus-es stop for passengers to board or alight from a bus. It is a struc-ture constructed at a bus stop, to provide seating and protec-tion from the weather for the convenience of waiting passengers.

In this assignment, we were given a task to design and construct a temporary bus shelter for 5 to 6 people on a scale of 1:5. The bus shelter model has a maximum height of 600mm and a maximum base of 400mm x 800mm. In order to create a stable and strong structure, we have to have a clear understanding of skeletal frames and its joints.

Before constructing the bus shelter, we had to chose two forms to combine into a design form to base on. Initially, we chose a hexagonal prism and a cuboid to create the bus shelter design. But after some discussion and trial and error through model making, it was amended to a pentagonal prism to provide stability and strength to support the loads and forces exerted on the shelter.

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The choice of materials must be waterproof and be able to withstand the humid and tropical climate that we have in Malaysia. The design should accomodate to the heavy rainfall and the strong solar radiation.

Weather Resistant Stable Ergonomics Suitability of Materials

The construction of the shelter has to be able to resists lateral and horizontal forces without collapsing to dead or live loads or uplifting due to wind loads.

The shelter has to be built according to human anthropometry for human comfort and convenience of user. It should provide sufficient space for maximum capacity of users.

Materials chosen need to be appropriate and have high durability and strength to efficiently support the structure. It should be locally available and eco-friendly.

2.0 DESIGN CONSIDERATIONS 04

2.1 DESIGN DEVELOPMENT

The initial design only had a seating and an X-bracing to support lateral and horizontal forces. The overall design did not fuly apply all the struc-tural components required from the brief and was deemed unsuitable as it had a weak stability.

Mock Up 1 Mock Up 2

Mock Up 3

The idea of the angled roof was maintained with addition of extra beams, columns and X-bracing to increase stability and safety of the structure. The structure however was quite long and required additional beams and columns for support.

The X-bracing was retained in the next model although reduced to increase stability. A roof beam was added to suport the load of the cantilevered pitched roof.

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The finalized design is a timber skeletal frame structure with minor modifications from the previous mock up such as adding more structural components and adjusting the dimensions of rafters, bearer and joist.

2.2 FINAL DESIGN 06

3000

2000

250

400

3.0 ORTHOGRAPHIC DRAWINGS 07

Foundation PlanScale 1:25

Floor PlanScale 1:25

3900

2000

415

150

150

083.0 ORTHOGRAPHIC DRAWINGS

2200

3900

300

Roof PlanScale 1:25

3650

3000

25500

093.0 ORTHOGRAPHIC DRAWINGS

Front ElevationScale 1:25

Side ElevationScale 1:25

4.0 CONSTRUCTION PROCESS 10

Preparation of Materials

Footing

Each timber component is measured and marked to the correct dimensions to be cut.

A timber block is used to represent the concrete footing in this 1:5 model due to sustainability issues and con-venience as requested by our tutor.

The wood is cut according to the marked dimensions with help

assisted by workers at the workshop for safety and accuracy

reasons.

Gum is applied to attached the timber pad footing and the stump.

The ends of the wood are polished and sanded to smoothen

out the rough edges.

The footing is further strengthen by nailing it.

The columns, beams, rafters, joists, stump and footings.

The complete pad footing and stump.


Base Frame & Flooring

Beams & Columns

Post anchor brackets are screwed down unto the foot-ing and then screwed unto the

ground beams or column.

The timber beams and columns are measured, marked and cut

to create half lap joints.

The spacing for the joists are marked and then secured to the

beam using an L bracket.

Nuts and bolts of suitable size are prepared to secure the beam and

column together.

The position of the joist beneath is marked on the floor panels to

be accurately nailed.

A drill is used to create holes for the nut and bolt.

The floor panels are nailed to the joist and beam.

The lap joint is then fixed tightly with nut and bolt in the

intersection of the beams and columns.


Roofing

The rafters are cut to form a birdsmouth joint to connect

with the roof beam.

The rafters are placed with the specific spacings and then nailed

to ensure stability.

A drill is used to screw in the battens to the rafters.

The roof rafters, beams and battens.

Seating

The seating panels are nailed to the noggins.

Timber blocks are nailed together to form a U shaped

column for the seats.

The bracings are nailed to the columns.

The centre of the cross bracing is tighten using nuts and bolts.

Bracing


Roofing

Two corrugated steel sheet is placed with a metal ridge cap placed at the centre of both sheets to prevent leakage of rainwater.

The sheets are connected through rivets.

The excess ridge cap os trimmed to fit the bus shelter.

The final model of the temporary bus shelter

5.0 CONSTRUCTION DETAILS 14

Details

Foundation Plan

Connections

Concrete Pad Footing

b) Pad footing to ground beamsPost anchor brackets are also used to connect the footing to the ground beams.

a) Pad footing to columnsPost anchor brackets secured with nuts and bolts are used to strengthen the connection between the timber column and con-crete footing.

Footing dimensions: 400 x 400 x 200, 250 x 250 x 300

Column

Column

Post anchor bracket

Post anchor bracket

Footing

Footing


Details

Foundation Plan

Connections

Timber Base Frame

b) Ground beam to columnRebated butt joint is used to connect the ground beam to column and then tightly secured with an anchor bracket and nuts and bolts to further strengthen the joint.

a) Joist to ground beam Timber joist are cut separately to be flushed and connected to the ground beams using an L-bracket secured with nuts and bolts.

Front & back joist dimensions: 50 x 125 x 887.5Joist spacing: 600Rim joist dimensions:50 x 125 x 775Front ground beam dimensions: 75 x 200 x 3000Middle and back ground beam: 75 x 200 x 2700

Joist

Column

L- bracket

Post anchor bracket

Ground Beam

Ground beam


Details

Floor Plan

Connections

Timber Flooring

a) Floor panel to ground beam/joistEach timber floor panel is secured by nailing it to each floor joist underneath. The floor panel located at the ends are also nailed to the ground beam.

Floor decking dimension: 25 x 2000 x 3000Floor panel dimension:25 x 100 x 3000

Timber planks

Ground BeamNails


Details

Perspective

Connections

Timber Seat

b) Seat panel to nogginThe ends of the seat panels are secured by nailing it down to the noggin between the two columns.

a) Seat Column to flooringSeat columns are fasten to the floor decking with L brackets.

Seat dimension:25 x 415 x 3000Seat panel dimension:25 x 100 x 3000Seat Column dimension:100 x 100 x 475

Nails

Flooring

Noggins

Seat Column

L-bracket

Seat Panels


Details

Perspective

Connections

Timber Column

b) Front column to tie beamHalf lap joint is used to connect the centre of the tie beams to the front column and is secured with nuts and bolts.

a) Back column to tie beamRebated butt joint is used to allow the tie beams to rest flushed on the back column and is fastened using nuts and bolts.

Front column dimension: 150 x 150 x 2900Back column dimension:150 x 150 x 2560

Back Column

Front Column

Roof Beam

Tie Beam


Details

Perspective

Connections

Timber Roof

b) Rafter to beamThe rafter is connected to the roof beams by using a birdsmouth joint.

a)Tie beam to roof beamThe roof beam is rested on top of the tie beam and fasten using L brackets.

Roof beam dimension: 75 x 125 x 3000Tie beam dimension: 75 x 125 x 2000 Ridge beam dimension: 75 x 175 x 3000Rafter dimension: 50 x 75 x 1065Batten dimension: 50 x 75 x 3900

Column

L bracket

RafterBeam

Roof Beam

6.0 DESIGN ANALYSIS

The long bench allows more people to sit while waiting for the bus.

The absence of walls maximises the ventilation in the bus shelter and views towards the surround-ings. This prevents from storing up and creates a comfortable space of the bus shelter.

A 2-way roof allows more sheltered space suit-able for tropical weather. The parallel valley troughs of the corrugated metal sheets help to direct water flow in one direction.

Overhang on both front and back aids in the sun shading function of the bus shelter.

The whole structure is elevated above the ground to prevent moisture from the ground to have di-rect contact with the timber structure.

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Humidity

Space

Rain Flow

Sun Shading

Ventilation

6.1 TIMBER SKELETAL FRAME CONSTRUCTION

Members of Bus Shelter

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Corrugated steel sheet roof

Timber ground beam

Timber rafterTimber batten

Timber roof beam

Timber tie beam

Timber column

Timber X bracing

Timber K bracing

Timber floor decking

Timber rim joist

Timber joist

Timber noggin

Concrete pad foundationConcrete stump


Horizontal and Vertical Members

Skeletal frame construction is the internal supporting structure which consists of horizontal and vertical members to support the floor, roof and wall in a structure.The structure had to transfer vertical forces such as dead loads, live loads, rain and gravity through the members of the frame to a suitable founda-tion as well as withstand lateral forces such as earthquake and wind.

Vertical members: column, rafter, seat column Structural element that transmits, through compression the weight of the structure above to other structural elements

Horizontal members: ridge beam, purlin, tie beam, roof beam, joist, bearer, seat beamStructural element that carries loads transverse to its longitudinal axis by its internal resistances to bending.

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Timber Bracing Systems

Structure require braces to resists sway movement from lateral forces that is caused by strong winds and disasters such as earthquakes.Concentric braced frames are used where both ends of the brace join at the end points of the other framing members to form a stiff frame. This type of bracing provides the same strength in both directions.

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Cross Bracing K Bracing

6.2 LOADS AND FORCES

Load System: Two Way Slab System

The structure’s load transfer mechanism channels the load to the ground in two directions. This is due to the ratio of the longer ground beam span to shorter joist is less than 2.

Longer ground beam span = 3 Shorter joist span 2 = 1.5 > 2

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6.2 LOADS AND FORCES

a) Dead Loads• Dead loads are static forces that act vertically downward on the

structure caused by the permanent weight of the elements and com-ponents.

• A permanent force that remains throughout the lifespan of the struc-ture.

b) Live Loads• Live loads are moving or moveable loads on a structure resulting on a struc-

ture from occupancy and rainfall• The intensity of the live loads varies depending on the usage and capacity.• The pitched angle roof prevents the accumulation of rain on the roof, thus

increase the ability to withstand weather

c) Wind Load• Open structure allows even distribution of wind force into the bus shelter,

causing balanced air pressure above and below the roof, reducing uplift force on the roof

Load Systems: External Forces

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6.2 MATERIALITY

TimberMeranti Wood - Columns, beams, rafters, battens, floor joist, seatingResak Wood - StumpPlywood - Flooring

Advantages:• Sustainable and reusable• High in durability and strength• Good insulator• Cost efficient

Disadvantages• If not treated, it has a low fire resistance

and is susceptible to shrinking, swelling and disolouration

In-situ ConcretePad footing

Advantages:• High compressive strength• Good weather resistance • Long-lasting and durable• Non- combustible

Disadvantages• Relatively low tensile strength

Corrugated Steel SheetRoofing

Advantages:• High durability and long- lasting• Provides protection against UV rays• Albe to withstand wind loads• Maximum shedding of rain and minimal

leakage

Disadvantages• May cause noise during rainfall• Susceptible to denting

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6.3 LOAD TEST 27

RoofTest subject: 500ml water bottle (0.5kg each)Unit: 6 water bottlesTotal load: 3kgRepresentation: Live loads that are imposed on the roof, such as rain.Test Result: Successful. The structure is able to withstand the live loads imposed on it.

BenchTest subject: Book A (3 kg each), Book B (1.2kg each)Unit: 1 Book A, 2 Book BTotal load: 5.4 kgRepresentation: Live Loads imposed by peo-ple when they sit on the bench.Test Result: Successful. The structure is able to withstand the live loads imposed on it.

Timber DeckingTest subject: 500ml water bottle (0.5kg each), Book A (3 kg each), Book B (1.2kg each)Unit: 6 water bottles, 1 Book A, 2 Book bTotal load: 9.4kgRepresentation: Live Loads imposed on the timber floor deckingTest Result: Successful. The structure is able to withstand the live loads imposed on it.

7.0 RENDERING OF MODEL 28

8.0CONCLUSION

In conclusion, this exploration has allowed us to apply the knowl-edge of skeletal construction in a practical design of a bus shelter. During the design development, it was crucial to find a balance between design and practical constructability.

Through detailed and thorough research on various structural joints, appropriate connections were chosen to ensure stability and withstand the applied loads and forces. The importance of the choice of building materials were also highlighted in order to maintain good stability. Over-all, our temporary bus shelter was design and constructed to accom-modate the Malaysian weather and provide users maximum comfort.

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9.0REFERENCES

Woodworking joints. (2017). Craftsmanspace.com. Retrieved 7 October 2017, from http://www.craftsmanspace.com/knowledge/woodworking-joints.html

Ching, F., & Adams, C. (2001). Building construction illustrated (3rd ed.). Canada: John Wiley & Sons, Inc.

Baylor, C. (2017). 13 Methods of Wood Joinery Every Woodworker Should Know. The Spruce. Retrieved 7 October 2017, from https://www.thespruce.com/wood-join-ery-types-3536631

Lyons, A. (2007). Materials for architects and builders (3rd ed.). London: Routledge, Taylor & Francis Group.

frames. (2012). Construction-greatopportunity.blogspot.my. Retrieved 10 October 2017, from http://construction-greatopportunity.blogspot.my/2012/03/frames.html

Difference between One Way Slab and Two Way Slab |. (2017). CIVIL READ. Re-trieved 11 October 2017, from https://civilread.com/differences-one-way-slab-two-way-slab/

Timber structures Seismic Resilience. (2013). Seismicresilience.org.nz. Retrieved 11 October 2017, from http://www.seismicresilience.org.nz/topics/superstructure/commercial-buildings/timber-structures/

What is Cross Bracing?. (2017). wiseGEEK. Retrieved 11 October 2017, from http://www.wisegeek.com/what-is-cross-bracing.htm

Braced frames Seismic Resilience. (2017). Seismicresilience.org.nz. Retrieved 12 October 2017, from http://www.seismicresilience.org.nz/topics/superstructure/seismic-design-concepts/braced-frames/

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