Building Structures 1

BUILDING STRUCTURES (BLD61003)

PROJECT 1: STRUCTURAL DESIGN POST MORTEM

KAMPUNG PULAI VISITOR INTERPRETIVE CENTRE

TUTOR: MR. MOHD. ADIB RAMLI CHEN LIAN LIAN (AGNES) CHONG MIN (CADENCE) LEE JIA YEE (REBECCA) NG JING YUAN NANG AYE MYAT MON SIM LI MEI

0333357 0333339 0333311 0331472 0328627 0328623

FOREWORD

This report focuses mainly on identifying the issue of structural components of the existing building of the Visitor Interpretive Center and how can these issues can be tackled and addressed through several improvisations on the structural design and a thorough study and analysis of the existing structural design applied in the previous semester three project.

In a group of 6, we are required to discuss and apply the solutions based on our knowledge and information extracted from various sources which would give us an idea on how can we go about in improving the existing design with a new proposal scheme that fully utilizes a series of appropriate structural systems available.

Apart from that, we are also required to discuss on the existing structural design whilst taking into consideration of several aspects namely; safety, feasibility, economy, optimization, integration, stability, strength or rigidity of the structural system.

We would like to thank our groupmates for contributing much of their time, knowledge and effort in the process of making this report a success. From the beginning till the end of the project, we have certainly gained a greater insights on the importance of designing appropriate, reliable and safe structural components of a building.

Besides, we would need to identify the structural systems and forces as well as applying structural theories in designing structural elements and appraise the technical standards as well as structural design codes and loading codes to be applied to building design.

Lastly, this project wouldn’t have been possible without the assistance and guidance from our tutor, Mr. Mohd Adib Ramli; with that, we would to extend our thanks and gratitude for all the feedback that suggestions that has helped us immensely.

TABLE OF CONTENT 1.O

EXISTING DESIGN REVIEW

2.0

EXISTING ORTHOGRAPHIC DRAWINGS

3.0

DESIGN APPRAISAL & PROPOSED SOLUTION 3.1

FOUNDATION 3.1.1 INTRODUCTION 3.1.2 FACTORS DETERMINING THE TYPES OF FOUNDATION 3.1.3 SHALLOW AND DEEP FOUNDATION 3.1.4 COMPARISON BETWEEN 3 TYPES OF FOUNDATION 3.1.5 COMPARISON BETWEEN 2 TYPES OF PILE FOUNDATION 3.1.6 STABILITY & FEASIBILITY

3.2

SKELETAL FRAMING STRUCTURE 3.2.1 FEASIBILITY 3.2.2 STABILITY 3.2.3 ECONOMY 3.2.4 SAFETY

3.3

FLOOR 3.3.1 STABILITY 3.3.2 OPTIMIZATION 3.3.3 FEASIBILITY 3.3.4 ECONOMY

3.4

ROOF 3.4.1 STABILITY 3.4.2 INTEGRATION 3.4.3 OPTIMIZATION

1 3

8

19

30

38

TABLE OF CONTENT 3.5

BRIDGE 3.5.1 STRUCTURAL COMPONENTS OF THE EXISTING BRIDGE 3.5.2 STABILITY 3.5.3 ECONOMY 3.5.4 SAFETY

45

4.0

MODIFIED ORTHOGRAPHIC DRAWINGS

51

5.0

CONCLUSION

6.0

REFERENCES

52 54

1.0 EXISTING DESIGN REVIEW This Visitor Interpretive Center is a gesture to preserve and sustain the genius loci of Kampung Pulai village which can be translated as “KNOT”.

KNOT has multiple and sophisticated meanings. As one can be experienced from the way of life of the Pulai villagers, they hold on to their roots as always. They appreciate and cherish their cultural beliefs and customs.

This is a rather rare scenario in the modern times. The villagers also strongly-bonded with each other as they always enjoy helping each other in times of events and in their daily lives.

Main Objectives: Creating opportunities for outsiders to merge with the Pulai people, forging a ‘knot’ between communities and visitors.

Capturing the fabulous natural gifts, the sounds of water, the smell of rain, the shower of sun let to instil a sense of place to visitors.

A place to celebrate and learn the meaningful values of the Pulai people.

1

1.0 EXISTING DESIGN REVIEW

Above the Surface Approaching the VIC via a newly-proposed bridge, one is in direct immersed relationship with the enveloping hospitality and liveliness of the Pulai daily culture.

Journey Visitors are free to sit around the void or the hanging verandah to simply enjoy the natural beauty of the surroundings.

Footprint to River Beginnings The past has become a place to rejuvenate and relax while acknowledging its importance.

Journey Moving around the central void, experiencing the intangible of the space rearing the river water owing beneath the sun, cascading from above.

2

EXISTING ORTHOGRAPHIC DRAWINGS

3

FOUNDATION

8

3.1 FOUNDATION 3.1.1 INTRODUCTION

Figure 3.1: An aerial photo of the entire site where the plot of land highlighted in red is where the building sits on whereas the community hall nearby is also supported by slender concrete columns and beams (in yellow) which transfers load to the piling foundation underground.

Figure 3.2: An isometric drawing of the micro site with the structure of the building (highlighted in red) which sits in between the river and the lake.

Foundations provide support to the structure above through columns and the loads were eventually transferred from the structure to the soil below ground level.

Hence, a thorough study through comparison of several alternatives of foundations in relation to the context of the site will be conducted in order to address the problem statement with a proposed solution before a conclusion will be drawn based on the most suitable and reliable foundation that can be applied in the construction of this KNOT Visitor Interpretive Center, while taking into account of three different aspects, namely stability, feasibility and economy.

Foundation is one of the most crucial aspect of a building structural component in ensuring that the lifespan of the building would last for the next several decades; whilst having to withstand all sorts of environmental impact in the surroundings as well as dead loads that is imposed by the structural components of the building itself and live loads.

9

3.1 FOUNDATION 3.1.2 FACTORS DETERMINING THE TYPES OF FOUNDATION In order to identify the suitable foundation to be used, there are several considerations or factors to be taken into consideration:

Figure 3.3: The building is designed to be elevated from the ground level, hence multiple concrete columns and pilotis can be seen which is supported by an appropriate foundation system.

1.

Total load from the structure above

Figure 3.4: A site plan that shows the position of columns (in red) which is supported by the foundations on the structural ground floor plan in relation to the site where some columns is submerged partially into the river and lake.

3.

The total load that would be transmitted from the live and dead load has to be taken into consideration in order to make sure that the capacity of the columns and foundation below would be able to withstand the overall load that is imposed onto it as shown in Figure 3.3.

2.

The water level would consistently be 3 meters high from the riverbed except during monsoon season in the region which happens yearly. It is also recorded that massive flood would occur once every 4 years with strong currents where the water would rise up to the height of a 4 storey-building. Hence, the building has to be elevated above ground by multiple columns which transfers its load to the foundations below.

Soil conditions at site The soil condition in Kampung Pulai is rather firm and stable despite it being located off the riverbanks.

Hence, it would be able to support the the drilling pressure imposed onto the soil condition once foundation works are carried out in order to lift and support the weight of the building above.

Water level of the river

4.

Location of the building It is located in an average-paced developed area surrounded by well-preserved lush greeneries and natural limestone caves. The contour of the site is rather mild with a gentle slope at the edge of the 10 riverbank. (Figure 3.4)

3.1 FOUNDATION 3.1.3 SHALLOW AND DEEP FOUNDATION

PROBLEM STATEMENT

Figure 3.7: Example of shallow foundation (left) and deep foundation (right) where both of these foundations contains reinforcing bars before concrete are poured over them to create a strong and rigid foundation.

Figure 3.5: Existing design where no proper foundation system is applied based on the longitudinal section drawing above.

Figure 3.6: A rendered perspective of the building where it’s mainly surrounded by green, natural elements.

The vibrating effect of piling activity has to take into account as another existing structure of concrete beams and columns are located right opposite (in red).

In the existing design of the KNOT Visitor Interpretive Center (VIC), no proper foundation systems were incorporated into the overall design as shown in Figure 3.5 and Figure 3.6. Hence, various study on the types of foundations that’s deemed suitable to be built on site will be carried out and tabulated in the following tables.

There are two types of foundations, namely shallow and deep foundations.

When the bearing capacity of the surface soil is adequate to carry the loads imposed by the structure above, shallow footings are usually used.

On the contrary, when the bearing capacity of the surface soil is not sufficient to carry the loads imposed by the structure, deep foundation is used.

To sum it up, in regardless of the loads imposed from the structure above, the loads have to be transferred to a deeper level where the soil layer has a higher bearing capacity to prevent any possible structural mishaps on the building.

In this case where our building was built alongside riverbank, deep foundation is needed to withstand strong current and unfavourable weather that occurs every once in a while.

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3.1 FOUNDATION 3.1.4 COMPARISON BETWEEN 3 TYPES OF FOUNDATION

Types of Foundation

Characteristics of Foundation

Pier Foundation

Caisson

Pile Foundation

Pier foundation is a type of deep foundation.

Caissons are watertight structures made up of wood, steel or reinforced concrete.

Pile foundation is a type of deep foundation.

It consists of a cylindrical column of large diameter to support and transfer large superimposed loads to the firm strata below.

It is normally built above the ground level and then sunken into the ground.

The loads are taken to a low level by means of vertical timber, concrete or steel.

Pile resistance

Masonry or concrete piers and drilled caissons.

Box, open, pneumatic, monolithic, floating, excavated, etc.

End-bearing piles, friction piles, compaction piles, anchor piles, tension or uplift piles, sheet and batter piles.

Method of Construction

Pier is typically dug out and cast in place using forms or being inserted down into the bedrock.

Caissons are driven into the surface of the soil, putting a box into underwater and pouring/ filling it with concrete.

Piles are driven into the surface of the soil driven by a piledriver.

Presence of Footing

Yes

No

No

Table of Comparison on several aspects in the study of different types of foundation.

12

3.1 FOUNDATION CONCLUSION BASED ON THE COMPARISON MADE ON THE 3 TYPES OF FOUNDATION

Figure 3.8: Pier Foundation

Figure 3.10: Pile Foundation

After the comparison has been made based on several aspects as shown in Table 3.1, the most appropriate foundation system to be introduced for this VIC in particular is pile foundation.

This is because it is categorized under deep foundation where the bearing capacity of the surface soil at the site is not sufficient to carry the loads imposed by the structure above.

Figure 3.9: Caisson Foundation

Besides, it also does not require pad footing where piles would only be driven into the surface of the soil driven by a piledriver without involving much complexities in the process of getting it completed at site.

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3.1 FOUNDATION 3.1.5 COMPARISON BETWEEN 2 TYPES OF PILE FOUNDATION

Types of Pile Foundation

Characteristics of Foundation

Piling Materials

Bored Pile Foundation

Driven Pile Foundation

Bored pile, also called drilled shaft, is a type of reinforced-concrete foundation that supports structures with heavy vertical loads. A bored pile is a cast-in-place concrete pile, meaning the pile is cast on the construction site. This differs from other concrete pile foundations, like spun pile and reinforced concrete square pile foundations, which use precast concrete piles. Bored piling is commonly used for bridge work, tall buildings, and massive industrial complexes, all of which require deep foundations.

Driven piles, also known as displacement piles, are a commonly-used form of building foundation that provide support for structures, transferring their load to layers of soil or rock that have sufficient bearing capacity and suitable settlement characteristics.

Masonry or concrete piers and drilled caissons.

Piles of timber, prestressed concrete and steel are also used in this method.

Driven piles are commonly used to buildings, tanks, towers, walls and bridges.

support

Driven piles are very adaptable and can be installed to accommodate compression, tension or lateral loads, with speciďŹ cations set according to the needs of the structure, budget and soil conditions.

14

3.1 FOUNDATION 3.1.5 COMPARISON BETWEEN 2 TYPES OF PILE FOUNDATION

Advantages ●

●

● ● ●

●

●

Piles of variable lengths can be extended through soft, compressible, or swelling soils into suitable bearing material.

Piles can be extended to depths below frost penetration and seasonal moisture variation.

Large excavations and subsequent backfill are minimized.

Less disruption to adjacent soil occurs.

Vibration is relatively low, reducing disturbance of adjacent piles or structures.

High-capacity caissons can be constructed by expanding the base of the pile shaft up to three times the shaft diameter, thus eliminating the need for caps over groups of multiple piles.

For many design situations, bored piles offer higher capacities with potentially better economics than driven piles.

● ●

●

Piles can be pre-fabricated off-site which allows for efficient installation once on site.

Driven piles displace and compact the soil which increases the bearing capacity of the pile. Whereas, other deep foundations tend to require the removal of soil which can lead to subsidence and other structural problems.

They are cost-effective as a wide variety of materials and shapes can be easily fabricated to specified dimensions, which can result in the need for fewer piles on site.

●

●

They generally have superior structural strength to other forms of foundation. Their high lateral and bending resistance makes them ideal for challenging conditions such as wind, water, seismic loading, and so on.

Installation usually produces little spoil for removal and disposal.

15

3.1 FOUNDATION 3.1.5 COMPARISON BETWEEN 2 TYPES OF PILE FOUNDATION Disadvantages

● ●

●

Susceptible to “wasting” or “necking” in “squeezing” ground.

Concrete is not placed under ideal conditions and cannot be subsequently inspected.

Water under artesian pressure may pipe up pile shaft washing out cement.

●

● ●

●

●

Damage may occur in the pile at a position not visible from the surface during driving process.

Pile may get laterally displaced if it encounters any obstructions like rocks in the ground.

The length of pile is estimated before driving commences, but the accuracy of this assumption is only known on site, where short piles can be difficult to extend and long piles may prove to be expensive and wasteful.

Advance planning is required for handling and driving, as well as the heavy equipment on site.

It may not be possible to determine the exact length required and so splicing or cut-off techniques may be required which has time and cost implications.

● ●

Driven piles may not be suitable where the ground has poor drainage qualities.

Driven piles may not be suitable for compact sites, where the foundations of structures in close proximity may be affected by the vibrations caused by installation.

Cost

Less

More

16

3.1 FOUNDATION PROCESSES OF 2 TYPES OF PILES FOUNDATION

Phase 1: Casing Installation

Phase 2: Drilling

Phase 3: Install Reinforcement

Phase 4: Pouring of Concrete

Phase 5: Extract the Casing

Figure 3.11: Process of bored piling.

Figure 3.12: Process of driven piling beginning with the placement of pile (left), installation of pile by hammering it into the ground (center) and the steps are repeated until a small cap remains above the ground (right).

17

3.1 FOUNDATION 3.1.6 STABILITY & FEASIBILITY

Figure 3.13: A modiďŹ ed section drawings with the bored piles (highlighted in red) that has been introduced to address the issue of stability and feasibility in accordance to the given site and soil condition.

PROPOSED SOLUTION In order to ensure that the building will be feasible in remaining upright and stable if the building erected, bored pile foundation will be introduced in the construction of its foundation systems as shown in Figure 3.13.

This is because, being built on an embankment/ riverbank where strong current and waves can be unfavourable at times, the foundation that’s supporting the load from the columns above would need to be able to withstand the forces acted on it.

Besides, the concrete structure that is located right opposite (as shown in Figure 3.6) the VIC would also be affected if driven pile foundation is introduced as it may not be suitable for compact sites, where the foundations of structures in close proximity may be affected by the vibrations caused by installation.

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SKELETAL FRAMING STRUCTURE

19

3.2 SKELETAL FRAMING STRUCTURE 3.2.1 FEASIBILITY Columns Stud wall

Figure 3.14: Ground oor plan with columns and stud wall labelled.

PROBLEM STATEMENT Wood stud and post-and-beam framing

Irregular and disturbed load distribution

The requirement for stability against side loads and wind is high for load bearing structure. The existing design of the building consists of both wood post-and-beam framing and wood stud framing system (load bearing). The wood stud wall in the building consists of large opening which may resulted in the weakening of strength to the building.

The same sizes are aligned irregularly and not parallel to each other causing an uneven load distribution.The columns are not positioned systematically in a grid system which cause the distribution of uneven load from the slab above.

20

3.2 SKELETAL FRAMING STRUCTURE 3.2.1 FEASIBILITY Columns Stud wall

Figure 3.15: First floor plan of existing design with columns and stud wall labelled.

PROBLEM STATEMENT

Stud wall Opening

Wood stud and post-and-beam framing The initial first floor plan consists of high percentage of stud wall which acts as load bearing structure that support the weight of the roof. There are two columns only found at this plan. The wood stud wall are with large opening and most of the stud wall position are not aligned with the columns supporting the first floor beam and slab.

Figure 3.16: North elevation - stud wall with large openings highlighted.

21

3.2 SKELETAL FRAMING STRUCTURE 3.2.1 FEASIBILITY Columns

Figure 3.17: Ground floor structural plan of columns and beams.

PROPOSED SOLUTION Grid structural system Equal and even load distribution Two-way systems found in the structural system and the structures are designed to channel the loads acting on the building to the ground.

Regular grid define equal spans, allow the use of repetitive structural element, and offer the efficiency of structural continuity across a number of bays.

22

3.2 SKELETAL FRAMING STRUCTURE 3.2.1 FEASIBILITY Columns

Figure 3.18: First floor structural plan of columns and beams.

PROPOSED SOLUTION

Modifying proportions The grid can be made irregular, which creates different size, scales and proportions of modules in order to accommodate the specific dimensional requirements of spaces and functions of the existing building.

Steel reinforcement (rebar) Concrete Figure 3.19: Cross section of composite columns with reinforcement

23

3.2 SKELETAL FRAMING STRUCTURE 3.2.2 STABILITY Columns Beams Stud Wall

Figure 3.20: The existing ground floor plan with structural system components labelled.

PROBLEM STATEMENT Timber structures are sensitive to moisture fluctuation.

According to Oxley and Gobert, the main sources of dampness in buildings are direct penetration through the structure, faulty rainwater disposal, faulty plumbing and more which will lower the load bearing capacity and increase deformation.

Apart from that, the dimension of the timber can change due to seasoning. Moreover, the geometry of the joints should not be changed by shrinkage of the wood and bearing surfaces should remain in tight contact.

Structural element

Size

Column

120mm*160mm, 200mm*200mm

Beam

100mm*350mm Table of structural elements of existing design and sizes

Moreover, shear strength of timber is weak due to the knots, faults and cracks that appeared in wood and resulting in failure for structural purpose.

Less columns supporting the first floor and the beams constructed is not structurally supporting by the columns and stud walls below resulting instability floor. The timber stud wall acts as load bearing structure cannot support the load of floor and roof structures above.

24

3.2 SKELETAL FRAMING STRUCTURE 3.2.2 STABILITY

Increased depth of beam with steel reinforcement

Slab with steel reinforcement

Figure 3.22: Increased depth of beam for higher efficiency

Figure 3.21: Load distribution path from beam to column and to ground.

PROPOSED SOLUTION Reinforced concrete frames are commonly used in the structural designs of multi-storey buildings and are suitable for our building with three-storeys height approximately. This is due to the characteristics of the reinforced concrete structure which is able to span greater distance and carry heavier loads. The proposed reinforced concrete structure layout made up od column size of 200mm*200mm has a span range from 4m to 6m.

Structural element

Size

Column

200mm*200mm , 180mm*180mm

Beam

180mm*300mm

Table of structural elements of modified design and sizes

The efficiency of a beam is increased by increasing the depth which reduces the bending stresses of the beam.

The elastic modulus is the resistance of a material to elastic deformation under load. Elastic modulus of timber is 11000MN/m² compared with 27000MN/m² of reinforced concrete. Reinforced concrete is stiffer than timber which is a good resistant to bending.

25

3.2 SKELETAL FRAMING STRUCTURE 3.2.3 ECONOMY PROBLEM STATEMENT

Timber

Labour

Structural System

The initial material chosen for the building is timber. The cost required for material is cheaper at ďŹ rst however, it might required maintenance and treatments overtime and it will eventually increase the labour cost.

Due to the irregular arrangements of columns and beams causing inconvenient and unnecessary mistakes during construction, it will be resulting in requiring of more skilled workers to solve the issues.

Assignable to confusing structural system and building frameworks, a longer construction period is required and issues such as needing of more skilled workers and the cost to hire workers arise.

26

3.2 SKELETAL FRAMING STRUCTURE 3.2.3 ECONOMY PROPOSED SOLUTION

Building material

Life span

Reinforced concrete

Reinforced concrete (Cast in-situ)

75 - 100 years

Heavy hardwood (Sawn timber strips)

30-50 years

Material cheaper in long term, as reinforced concrete is more durable to weather. Laying out columns along the regular grid allow cost saving for beams and slabs.

Table of building material and life span

Building material

Price

Reinforced concrete (Cast in-situ)

RM250/m²

Heavy hardwood (Sawn timber strips)

RM852 - RM5508/mÂł

The cost of material is cheaper in long term, as reinforced concrete has high durability to weather and require less maintenance.

With application of grid structural system, lesser mistakes by labours and shorter time for construction is required which result in cost saving.

Table of building material and price

27

3.2 SKELETAL FRAMING STRUCTURE 3.2.4 SAFETY Timber Concrete

Figure 3.23: Timber and concrete column highlighted at section of existing design.

PROBLEM STATEMENT Combustibility When the frame is left exposed, the connections detailing is unfavourable for structural and visual reasons.

Combustibility is one of the major downside of using material in constructions. When timber is exposed to the higher temperature, it encounters structural, chemical and physical changes. Firstly, the moisture in the wood will

begin to evaporated when the wood is heated. Prolysis will takes place when the temperature of the wood reach around 300 °C causing of loss in mass and weaken the strength and mechanical properties. Finally, steel plates and bolt connections will be loosen and failed.

28

3.2 SKELETAL FRAMING STRUCTURE 3.2.4 SAFETY

Concrete

Figure 3.24: Proposed section with new concrete columns and beams highlighted.

PROPOSED SOLUTION Reinforced concrete Typically, concrete frames are rigid and qualify non-combustible and fire-resistive construction.

as

Hence it is a safe choice of using concrete for main structural components.

In reference of UBBL 1984, By law 158(3), 224, load bearing structures of the building- columns, floor slab and roof with thickness minimum of 180mm of unplastered concrete has a minimum fire rating period of 4 hours:

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FLOOR

30

3.3 FLOOR 3.3.1 STABILITY

Figure 3.25: The section of existing design highlighting the wood beams arranged in one direction in one way slab Timber one way slab

PROBLEM STATEMENT Initially, the first floor slab is wood framing structure with pinewood decking which cannot support the dead and live load of the floors. It is one way slab which the wood beams are arranged only in one direction and are not enough to support the load above. The span between each beam is 3000mm but there is no column supporting. It may also cause the bending of timber decking. When high stress is applied beyond the elastic range, failure may occur due to the bending force within the decking.

Wood framing structure with pinewood decking

31

3.3 FLOOR 3.3.1 STABILITY One-way slab

Two-way slab

Figure 3.26: Proposed structural ground floor plan indicating types of slab

Figure 3.27: Proposed structural first floor plan indicating types of slab

32

3.3 FLOOR 3.3.1 STABILITY

Pinewood Decking

Concrete Slab Concrete Beam

Steel Reinforcement

Figure 3.28: Reinforced concrete slab with reinforced beam with thermally modified wood decking

Figure 3.29: Concrete two way slab

Lx Ly

Figure 3.30: Concrete one way slab

≤ 2, One-way slab ≥ 2, Two-way slab

PROPOSED SOLUTION To solve the issue, RC slab is used instead of wood joist floor.

RC slab has higher compressive strength and can withstand higher amount of tensile stress compared to wood joist floor.The RC beam structure can support the RC slab more sturdy and rigid which can prevent failure or bending.

To maintain the aesthetic value of timber, the RC slabs are covered with timber finishing. In conclusion, the overall aesthetic is maintained while achieving the stability of structure.

33

3.3 FLOOR 3.3.2 OPTIMIZATION Concrete

Figure 3.31: Exposed pinewood flooring at first floor of existing design.

PROBLEM STATEMENT

Initially, the first floor is built with pinewood decking. The first floor is an open space where part of the floor is exposed to sun and rain. It requires water-proof painting annually which need maintenance and increases the cost of installing.

The gaps between the timber decking cause water leaking problem from first floor to ground floor.

34

3.3 FLOOR 3.3.2 OPTIMIZATION Concrete Timber

Wood Joist Concrete slab

Skirtboard Pinewood decking

Figure 3.33: Installation of pinewood decking on concrete slab

Figure 3.32: Flooring highlighted at first floor of proposed design.

Figure 3.34: Pinewood decking to timber joist connection

PROPOSED SOLUTION To remain the aesthetic, the flooring which exposed to sun and rain is replaced by concrete; while the interior still remains timber decking. Concrete slab is chosen to solve the water leaking problem.

Figure 3.35: Connection between wood joist and concrete slab

For deck installation, 75mm galvanised timber deck nail is used to fix the wood decking and wood joist. Skirtboard is also installed to cover the unsightly area under a deck.

35

3.3 FLOOR 3.3.3 FEASIBILITY

Figure 3.36: Section with ramp highlighted in red.

PROBLEM STATEMENT

PROPOSED SOLUTION

Timber framing structure is not suitable for ramp at first floor.

It is hard to shape and it might cost a lot for installation. It is not strong enough to handle the dead load and live load applied.

Timber framing structure is replaced by RC slab and RC beam, as it is easier to mould the shape of the ramp, at the same time to provide strength.

36

3.3 FLOOR 3.3.4 ECONOMY

150mm

Ground floor plan

Concrete Slab

Concrete

Figure 3.37: Concrete flooring highlighted at ground floor of existing design.

150mm

Concrete Beam

Steel Reinforcement

Figure 3.39: 150mm concrete slab with RC beam

Figure 3.38: 150mm concrete slab without beam `

PROBLEM STATEMENT

PROPOSED SOLUTION

Initially, the ground floor concrete slab is 150mm without beam. The concrete slab itself cannot support both the dead load and live load. Beam is needed to provide resistance to bending when load or force is applied.

250mm concrete slab without beam would requires more cement to form, it is more expensive compared to 150mm concrete slab with beam.

37

ROOF

38

3.4 ROOF 3.4.1 STABILITY

wood rafters

Figure3.40: Section drawing before modification

PROBLEM STATEMENT The existing roof structure which are highlighted in brown as seen in figure above are made up of couple pitched roof which consisted of ridge board, rafters and wall plates. The spanning of the roof varies, from largest span of 16.8, 12.8, 9.2, 8.2, 7.2, 5.8 meters, and the smallest span is 5.5 meters. The suitable span for couple roof are only 3.6m in maximum, this can be increased to 4.8m in the case of closed couple roof, and 5.5m in the case of collar roof. The spans of the roof of the visitor interpretive center are too large for the

simple pitched roof to be stable and this affects the integrity of the whole timber roof structures to fulfill it function. Apart from supporting its own dead load weight, the roof structures are functioned to transfer the wind and rain loads acting on the roofs to the load-bearing columns on which they rest. The existing large spanning roof structures are thus susceptible to collapse, and the safety of the occupants will be jeopardized.

39

3.4 ROOF 3.4.1 STABILITY PROPOSED SOLUTION Types of Truss

Steel Truss

Wood Truss

Advantage(s)

High strength-to-weight ratio.

Innate insulation to solar heat, energy efficient in interior cooling.

High tensile and compressive strength.

Low embodied energy materials, consumes much less energy to produce compared to steel trusses

Superior spanning capacity.

Recyclable materials, eco-friendly to environment.

Disadvantage(s)

Vulnerable to rust as a result of chronic moisture exposure when the coating worn out or defective vapor barriers.

Better performance in fire. The charring of the wood surfaces insulated the wood from further burning, the remain intact cross-section continues to support load. Glulam performs very well in intense heat of a fire, where temperatures can achieve 900 °C or higher. Unprotected steel members typically buckle and twist in such high temperatures, causing catastrophic collapse of the roof.

Treatment needed to protect from termite attack.

Treated to be moisture resistance to prevent rotting and decay of wood.

Heated easily due to solar heat gain, detrimental to interior thermal comfort

40

3.4 ROOF 3.4.1 STABILITY PROPOSED SOLUTION

Figure3.41: Section drawing after modification

Timber Roof Truss The proposed solution for large spanning roof would be the use of roof trusses. The preferable choice are wood trusses as compared to steel trusses. The use of timber in the long-run is more energy efficient. This is due to the fact of lower energy consumption – both the embodied energy required to extract, process, transport, and install building materials and the operational energy to cool the building.

The large spans will require designed roof trusses.

Wood trusses are prefabricated in plants according to the design specifications, this means higher quality control can be achieved during the manufacture process. The members of the trusses are all prefabricated and connected beforehand, thus it is quicker to install on site and save time, this may lead to a lower labour cost and the overall construction cost. All members in a trussed rafter are machined on all faces so that they are identical and of uniform thickness, ensuring a strong connections on both faces. On-site framing problems are eliminated as well.

41

3.4 ROOF 3.4.2 INTEGRATION wood trusses water cistern

Figure 3.42: Section drawing after modification

Problem Statement The remote site of the VIC from the main city coupled with the high rainfall in Malaysia climate, justified for the application of rainwater collection system. A water cisterns used for harvesting rainwater can significantly reduce the demand of treated drinking water from the grid for secondary uses such as toilet flushing, landscaping watering, washing kitchen appliances. In the pre-modification, separate room spaces in the VIC need to be designed to contain the water storage tank .This will results in additional take taken up and inefficient use of the space.

Proposed Solution The interstitial roof space created from the roof trusses can be utilized to integrate the water cistern placement. A ceiling can be provided to hide the services without affecting the aesthetic value of designated spaces for users. Moreover, additional separate space for water cistern storage can be saved up by optimizing the once undefined space by turning it as usable roof spaces without further compromising the floor-to-ceiling height.

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3.4 ROOF 3.4.3 OPTIMIZATION windows wood rafters

Figure 3.43: Section drawing before modification

Problem Statement The aspect of optimization in the design is often undermined, safety, feasibility, economy, practicality may be overlooked at the design stage, while aesthetics more often than not given the most priority. In the selected building. The designer’s want to design the tall and voluminous feel of the spaces at the first floor has compromised the economical use of spaces and practicality of large spanning by using simply rafter framing. The single-minded attention to aesthetics , e.i. primarily designed for used to experience the spaces in certain way has led to inefficient utilization of the roof spaces.

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3.4 ROOF 3.4.3 OPTIMIZATION windows wood trusses

Figure 3.44: Section drawing after modification

Proposed Solution After the issue of the roof structures and roof interstitial spaces are addressed in the post-modification version of the building, modifications to the window openings in the building’s design is needed. The top part of the window design could no longer follows the pitch of the roofline and change to rectilinear windows instead. The problem of the window height prior to modification is too tall to be anthropometric for users is addressed as well.

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BRIDGE

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3.5 BRIDGE 3.5.1 STRUCTURAL COMPONENTS OF THE EXISTING BRIDGE

Figure3.45: Section Drawing that cuts through the proposed suspended bridge (highlighted in red) which connects to the other end of the existing site (right) from the newly-designed building (left).

The existing bridge is currently in poor condition. It is safe to accommodate a small group of three users at a time.

The durability of the structure is relatively high to withstand the weather in Kampung Pulai over decades.

Figure 3.46: Side view of the existing suspended cable bridge.

The bridge can be improved in strength by using steel beams instead of timber beams, in order to accommodate larger live load.

Figure 3.47: Close-up view of the structural component of the bridge.

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3.5 BRIDGE 3.5.2 STABILITY

Timber slab Figure3.48: Section Drawing that cuts through the proposed suspended bridge (highlighted in maroon) which connects to the other end of the existing site (right) from the newly-designed building (left).

PROBLEM STATEMENT

Figure 3.49: The newly-designed suspension cable bridge’s walkway path (highlighted in red) is laid out with plywood sheets.

The initial structure of the bridge was designed without proper supporting system to accommodate the dead load and live load as shown in Figure. The bridge is only held together by the hand rails that connects from the VIC to the existing building. The other issue is the timber materiality as shown in Figure which is rather unsustainable and not durable as the span of the bridge is too long and is constantly exposed to the surrounding heat, moisture and rainwater.

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3.5 BRIDGE 3.5.2 STABILITY PROPOSED SOLUTION

Figure 3.49: The proposed suspension cable bridge’s walkway path (highlighted in red).

1.

Build cable system The suspension cables and stringers are cut and assembled. Stringers are adjusted to be specific height to keep the deck level.

2.

Consider the resonance The stringers were also spaced to deal with harmonic resonance.

3.

Span the cables and stringers Suspended between the rectangular arch structures.

4.

Add support beams

5.

Add decking

concrete

Steel Cable Steel hook welded to the top ‘flange’ of the I-Beam 150mm (Web)

6mm diamond thread aluminium stainless steel sheet Steel Cable (underneath I-Beam)

100mm (Flange) Figure 3.52: I-Beam

Figure 3.51: Suspended Bridge Component

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3.5 BRIDGE 3.5.3 ECONOMY PROBLEM STATEMENT

PROPOSED SOLUTION

Building material

Life span

Steel

65 - 70 years

Plywood

30 - 40 years

Table of building material and life span

Timber

Steel

The initial material chosen for the bridge is timber. The cost required for material is cheaper at ďŹ rst however, it is vulnerable to water damages and is prone to decay faster due to the weather condition in Kampung Pulai.

Proposed material for the bridge is steel. Material cheaper in long term, as steel is more durable to weather. Steel framing improves design efficiency, saves time, and reduces costs.

Building material

Price

Steel

RM16/kg

Plywood

RM422/m²

Table of building material and price

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3.5 BRIDGE 3.5.4 SAFETY

Figure 3.53: The newly-designed suspension cable bridge’s walkway path (highlighted in red) is laid out with plywood sheets.

PROBLEM STATEMENT Deterioration of wood Wood is a nutritional product for some plants and animals.

Biological deterioration of wood due to attack by decay

Humans can not digest cellulose and the other ďŹ ber

fungi, wood boring insects and marine borers during its

ingredients of wood, but some fungi and insects can digest it,

processing and in service has technical and economical

and use it as a nutritional product. Insects drill holes and drive

importance.

lines into wood. Even more dangerously, fungi cause the wood to decay partially and even completely.

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3.5 BRIDGE 3.5.4 SAFETY

6mm diamond thread aluminium stainless steel sheet

Figure 3.54: Proposed decking material - diamond thread aluminium stainless steel sheet.

Figure 3.55: Suspended Bridge Component

PROPOSED SOLUTION Aluminium stainless steel sheet Today, aluminium is the second most used metal in buildings after steel. Because of its ductility, aluminium can be formed into many shapes and proďŹ les. It is commonly used for building exteriors, with large wall panels requiring fewer joints, resulting in time-efficient installation.

Aluminium is remarkable for its low density and its ability to resist corrosion through the phenomenon of passivation.

Hence it is a safe choice of using aluminium stainless steel sheet for the decking of the bridge.

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MODIFIED ORTHOGRAPHIC DRAWINGS

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5.0 CONCLUSION To make sure the structure is buildable, structural systems and forces was identiďŹ ed, at the same time to apply structural theory in designing structural elements, appraise the technical standards as well as structural design codes and loading codes to be applied to building design.

Structural analysis has been conducted based on safety, feasibility, economy, optimization, integration, stability, strength, rigidity when implement the new structural design. The implementation of new structural design achieve both structural stability and safety.

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6.0 LIST OF FIGURES Figure 3.1: An aerial photo of the entire site where the plot of land highlighted in red is where the building sits on whereas the community hall nearby is also supported by slender concrete columns and beams (in yellow) which transfers load to the piling foundation underground.

Figure 3.2: An isometric drawing of the micro site with the structure of the building (highlighted in red) which sits in between the river and the lake.

Figure 3.3: The building is designed to be elevated from the ground level, hence multiple concrete columns and pilotis can be seen which is supported by an appropriate foundation system.

Figure 3.4: A site plan that shows the position of columns (in red) which is supported by the foundations on the structural ground floor plan in relation to the site where some columns is submerged partially into the river and lake.

Figure 3.5: Existing design where no proper foundation system is applied based on the longitudinal section drawing above.

Figure 3.6: A rendered perspective of the building where it’s mainly surrounded by green, natural elements. The vibrating effect of piling activity has to take into account as another existing structure of concrete beams and columns are located right opposite (in red).

Figure 3.7: Example of shallow foundation (left) and deep foundation (right) where both of these foundations contains reinforcing bars before concrete are poured over them to create a strong and rigid foundation.

Figure 3.8: Pier Foundation Figure 3.9: Caisson Foundation Figure 3.10: Pile Foundation Figure 3.11: Process of bored piling.

Figure 3.12: Process of driven piling beginning with the placement of pile (left), installation of pile by hammering it into the ground (center) and the steps are repeated until a small cap remains above the ground (right).

Figure 3.13: A modified section drawings with the bored piles (highlighted in red) that has been introduced to address the issue of stability and feasibility in accordance to the given site and soil condition.

Figure 3.14: Ground floor plan with columns and stud wall labelled.

Figure 3.15: First floor plan of existing design with columns and stud wall labelled.

Figure 3.16: North elevation - stud wall with large openings highlighted.

Figure 3.17: Ground floor structural plan of columns and beams.

Figure 3.18: First floor structural plan of columns and beams.

Figure 3.19: Cross section of composite columns with reinforcement Figure 3.20: The existing ground floor plan with structural system components labelled.

Figure 3.21: Load distribution path from beam to column and to ground.

Figure 3.22: Increased depth of beam for higher efficiency Figure 3.23: Timber and concrete column highlighted at section of existing design.

Figure 3.24: Proposed section with new concrete columns and beams highlighted.

Figure 3.25: The section of existing design highlighting the wood beams arranged in one direction in one way slab Figure 3.26: Proposed structural ground floor plan indicating types of slab Figure 3.27: Proposed structural first floor plan indicating types of slab Figure 3.28: Reinforced concrete slab with reinforced beam with thermally modified wood decking Figure 3.29: Concrete two way slab Figure 3.30: Concrete one way slab Figure 3.31: Exposed pinewood flooring at first floor of existing design.

Figure 3.32: Flooring highlighted at first floor of proposed design.

Figure 3.33: Installation of pinewood decking on concrete slab Figure 3.34: Pinewood decking to timber joist connection Figure 3.35: Connection between wood joist and concrete slab Figure 3.36: Section with ramp highlighted in red.

Figure 3.37: Concrete flooring highlighted at ground floor of existing design.

Figure 3.38: 150mm concrete slab without beam Figure 3.39: 150mm concrete slab with RC beam

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6.0 LIST OF FIGURES Figure3.40: Section drawing before modification Figure3.41: Section drawing after modification Figure 3.42: Section drawing after modification Figure 3.43: Section drawing before modification Figure 3.44: Section drawing after modification Figure3.45: Section Drawing that cuts through the proposed suspended bridge (highlighted in red) which connects to the other end of the existing site (right) from the newly-designed building (left).

Figure 3.46: Side view of the existing suspended cable bridge.

Figure 3.47: Close-up view of the structural component of the bridge.

Figure3.48: Section Drawing that cuts through the proposed suspended bridge (highlighted in maroon) which connects to the other end of the existing site (right) from the newly-designed building (left).

Figure 3.49: The proposed suspension cable bridge’s walkway path (highlighted in red).

Figure 3.51: Suspended Bridge Component Figure 3.52: I-Beam Figure 3.53: The newly-designed suspension cable bridge’s walkway path (highlighted in red) is laid out with plywood sheets.

Figure 3.54: Proposed decking material - diamond thread aluminium stainless steel sheet.

Figure 3.55: Suspended Bridge Component

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7.0 REFERENCES Ambrose, J. (1993). Building structures. John Wiley & Sons.

Ching, F. D. (2014). Building construction illustrated. Hoboken, NJ: John Wiley & Sons.

Ching, F. D. (2013). Building Structures Illustrated: Patterns, Systems, and Design. John Wiley & Sons Designing Buildings Wiki Share your construction industry knowledge www.designingbuildings.co.uk. (n.d.). Retrieved from https://www.designingbuildings.co.uk/wiki/Pile_foundations Gang-Nails System Limited. (n.d.). The Trussed Rafter Manual[PDF]. Gang-Nails System Limited.

Home.(n.d.).Retrieved from https://civiltoday.com/geotechnical-engineering/foundation-engineering/deep-foundation/176-pile-foundation-deďŹ nition-types Kassimali, A. (2009). Structural analysis. Cengage Learning Klevaklip. (n.d.). How to build a deck on a concrete slab. Retrieved from http://www.klevaklip.com.au/How-to-build-a-deck-on-a-concrete-slab Mirasha, G. (2018, September 10). Types of Foundation and their Uses in Building Construction. Retrieved from https://theconstructor.org/geotechnical/foundation-types-and-uses/9237/ Mustaq, M. (n.d.). Difference between piles, piers and caissons. Retrieved from https://civiltoday.com/geotechnical-engineering/foundation-engineering/deep-foundation/151-difference-between-piles-piers-c aissons Park, Robert, and Thomas Paulay. Reinforced concrete structures. John Wiley & Sons, 1975.

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