BUILDING CONSTRUCTION 2 Taylor's University

1. 1
School of Architecture, Building & Design
Centre for Modern Architecture Studies in Southeast Asia (MASSA)
Bachelor of Science (Honours) in Architecture
Building Construction II
Project I: Skeletal Construction (Temporary Bus Shelter)
Aaron Tan Weng Ming 0322400
Ong Jia Hui 0317752
Ong Min Junn 0317767
Tan Wen Hao 0319923
Tang Wei Xin 0322731
Tay Jit Ying 0319002
Tutor: Mr. Mohamed Rizal Mohamed

2. 2
Content
1.0 Introduction 3
1.1 Design Considerations
1.2 Design Concept
2.0 Materials 4
3.0 Design Process 5
4.0 Joints and Connections 6
4.1 Foundation
4.2 Column
4.3 Roof
5.0 Construction Process 8
6.0 Analysis 11
6.1 Stress Points
6.2 Load Distribution
6.3 Structural Movement
7.0 Conclusion 15
8.0 References 16

3. 3
1.0 Introduction
The objective of this project is to create an understanding of skeletal structure
and its relevant structural components, and also to understand how a skeletal
structure reacts under loading.
In this report, we will be analyzing the structural components, stress points, load
distribution and structural movement of our proposed 400mm x 800mm x 600mm
temporary bus shelter in order to demonstrate a convincing understanding of how
skeletal construction works.
1.1 Design Considerations
Before coming up with ideas and designs for our bus shelter, we took in some
design considerations which include it being:
- resistant to weather
- easily accessible
- light and portable
Aside from that, we aim to construct our bus shelter fully with recyclable and
biodegradable materials as it is more environmental friendly and also due to the
fact that the bus shelter is a momentary structure.
1.2 Design Concept
The design concept of our temporary bus shelter stems from the idea of wanting
it to be environmental friendly and easily relatable to the ordinary people. Hence,
we adopted the concept of using traditional methods such as weaving and
lashing in place of modern construction techniques.

4. 4
2.0 Materials
Bamboo
We opted bamboo as our primary construction material as it contains the utmost
important aspect that we are looking for – biodegradable, as well as being
weather resistant. Bamboo is also low in weight and can be transported and
worked easily. It can be worked with the simplest tools such as saw and drills as
long as we work along the cane axis.
With its lightness and strength, bamboo is an extreme product of nature. Its high
tensile strength, shear strength and bending strength is on average twice as
strong as most conventional structural timbers. Bamboo has proven to be durable
as it has long been used as scaffoldings. As compared with timber, bamboo is
able to withstand much more forces and can prevent buckling or crushing of the
main columns due to its strong, hollow and tensile structure
Our team decided against industrial material such as glass or steel as we hope to
achieve a more welcoming and warm feeling to our bus shelter by using bamboo.
Plastic Bottle
As with our concept of being environmental friendly, we decided to use plastic
bottles as our roof to reduce the demand of virgin materials and to maximize the
use of locally available resources.
We decided on plastic bottles as our roofing material due to its weather resistant
and lightweight property. Besides, it stands against corrosion and rot. Plastic
bottles of different colors are used for our roof aside from transparent ones as a
form of sun shading device. For our design, we adopted the form of an actual roof
tile by cutting the plastic bottles into half, and joining all the halves together.
In completion of this project, our team has collected and cleaned numerous
plastic bottles within the campus of Taylor’s University in the act of reusing them
instead of buying new ones, which will create more wastage.

5. 5
3.0 Design Process
i) As we are required to combine two forms for our bus shelter design, our
initial idea was to combine a hexagonal prism with a triangular prism.
However, it has been proven that this design was a failure as it was
given minimal structural considerations and the structural form itself is
wobbly and unstable in many ways.
ii) For our second design, we put in more thoughts and efforts in the
structural stability by adding in cross bracings and additional underpurlin
and rafters. We changed our two basic forms as well into square
pyramid and tetrahedron as they are considered as two of the most
stable form by the team.
However, stable as it was, this design was proven to have too many
unnecessary supporting structure and we were advised to cut down on
some.
iii) Our final design was derived from the second design, having only
making some small amendments by removing the cross bracing at the
back, some redundant supporting structure, and changing the basic
forms to a cuboid and tetrahedron.
Aside from the roof that is made out of plastic bottles, our final design
comprises of a full bamboo structure to match our concept of being
biodegradable and recyclable.
Front Elevation Side Elevation Plan
Scale: 1:100

6. 6
4.0 Joints and Connections
In order to maintain that vernacular and traditional look, the joints and
connections of our bamboo structure uses none other than the traditional lashing
methods. In addition, our team added in bolts and nuts, brackets, and screws to
the joints as assurance that the structural components do not deform and give
way to the loads.
Bolts and Nuts Bracket Screws
4.1 Foundation
Single post footing is implemented to the two tripods of 6 columns. The
foundation is 400mm x 400mm x 400mm deep in the footing where the culms
directly fit into the concrete footing. The columns are erected over concrete to
prevent ground contact and reduce the risk of termite infestation.
4.2 Column
Triangle prism is selected as our primary supporting structure as it is the most
stable shape with a consistent low center of gravity while utilizing the maximum
height in a given space.
Three bamboos are bonded together to form a bamboo tripod by using gyn
lashings. Gyn lashings are generally used in fastening three long components in
a rigid manner. The support is positioned in a way that the ends connect at the
nodes for maximum strength. Lashings are needed to secure the bamboos from
cracking.
Diagonal braces are applied to the connections of the columns and bases to
provide extra stability. The braces are staggered and connected at different
nodes to avoid multiple holes that may weaken the bamboos if drilled at the same
point.
Gyn lashings are used for the connection of the tripod columns.

7. 7
4.3 Roof
The core support of the cantilevered roof is the back column to minimalize the
weight of the entire structure. The cantilevered roof beam is laid right above the
columns and secured by wood plus and ropes. The rafters and purlins support
the loads from sheathing.
Aside from the skeletal structure that was secured using the square lashing
method, our roof was made entirely from plastic bottles so that it is resistant
against rain and direct sunlight. We connect the plastic bottles together by cutting
them into halves and stapled them together to form our “roof tiles”.
Stapled connection for plastic bottles
Flow of rain water down
the plastic bottle roof
Square lashings with added bolts and nuts are used to secure the
connections of roof

8. 8
5.0 Construction Process
1. The bamboos for each part are
being separated and labelled with
masking tape.
2. The intended measurements are
being measured and marked down
using a marker pen.
3. Bamboos are being sawed off into
the intended lengths.
4. Another alternative – cutting – is
used to get rid of the excess bamboo
length.
5. The bamboos are being hacked
into half.
7. The sawed bamboos are arranged in a triangular manner to form the base for
the tripod columns. Brackets are being added to it.
6. Bamboos were being cut into half
for the decking and back of the bus
shelter.

9. 9
8. The base for the tripod is
completed.
9. The bamboos are being lashed
together to form the tripod column.
10. Concrete for the foundation is
being casted and left aside.
12. Holes are being drilled. 13. Screws, bolts and nuts are being
inserted into the drilled holes.
11. The tripod columns are being
casted into the cement foundation.
14. Lashings are added to the base of
the tripod columns.
15. Lashings are added to most of the
joints to secure their stability.
16. The process of drilling, lashing
and inserting metal connectors are
repeated throughout the process.
17. The decking is being secured by
connecting the bamboos using strings.
18. Purlins and rafters are being
secured by lashings and metal
connectors.

10. 10
27. The final model is completed.

11. 11
Side Elevation
Front Elevation
6.0 Test Analysis
After coming up with the design that we deemed final, we run some tests on the
stress points, load distributions and structural movement of the bus shelter to
further understand and analyze the structure.
6.1 Stress Points
Mainly, the stress points are more focused towards the joints of the main
structural elements due to the direction of the load that is dispersed throughout
the structure. The stress points are also concentrated towards the joints because
they are the weakest part of each of element.
Most of the stress points located at the joints toward the top are due to the dead
load of the roof components. The joints are the only points where the roof is
connected to the columns and hence, the load of the roof is directed towards
those points. With the addition of live load such as rain and wind load, more
stress is directed towards those points not only downwards but also upwards due
to the uplift of the wind pressure.
The most stress is located at the connections at the bottom where the columns
meet the ground beams and the foundation. There is where most of the dead
load and live load is directed towards. However, even though it has a very high
amount of stress on those joints, it is still able to support the structure due to a
larger surface area of the main structural columns. This causes lesser pressure
on the foundation which is then diffused towards the ground.
Dead load: roof
Live load: rain, wind
Dead and live load
Live load
Live load: human
Dead and live load
Live load
Larger surface
area at the
bottom assists in
stress point
distribution

12. 12
Dead load of
roof and
columns are
being
transferred
down
Load is being
dispersed and
decreased as
they go
downwards
The dispersed and reduced
load are then transferred to
the ground
6.2 Load Distribution
Dead Load
The overall dead load of the structure consists of the roof structures followed by
the columns. These components are the source of most the dead load and this
causes a high compressive force from the top of the structure.
The joint has a high amount of stress directed on it due to the concentrated
amount of load over a small area but then it is quickly dispersed over 12 columns,
reducing the pressure directed on the joints. The arrangement of tetrahedron
columns allows the columns to be more stable as they are slanted but supported
by each other, even without the need of bracings.
The columns meet the ground beams at the bottom and are connected, creating
a larger base area for the load to be distributed. Hence, the pressure directed
towards the ground is reduced. The columns continue below the ground beams
and connect with the pad foot foundations to allow a stable structure and prevent
the structure from tilting.
More load
Lesser load

13. 13
The structure also faces different type of forces such as the tension of the
structure. Tension occurs when there is force acting on the columns, causing
them to be pulled apart. However, to overcome the tension acting on the columns,
several beams acts as ties to resists tensile stress.
The columns face tensile stress which causes the columns to collapse backwards,
losing stability of the roof support. To overcome the problem, the roof beams and
the beams located at the seats act as lateral ties to prevent the back columns
from collapsing. These ties increase the tensile strength of the structure as it ties
the back columns with main columns at the tripod.
The roof beam and the lower beam, which acts as a seat also acts as lateral ties
to increase tensile strength between the two sets of columns. Both sets of
columns are tied together, thus increasing the overall stability and the tensile
strength of the structure. Without these lateral ties, each set of columns is at risk
at collapsing due to its height even though it has a large base area.
Apart from these forces that are the main threat to the structure, other forces
such as torque and shear force pose a lower threat to the structure. The structure
itself is strong enough to withstand such forces.
Tensile strength
Tension
Tension
Tensile strength

14. 14
Live Load
Considering the structure as a bus shelter, the main live loads that affect the
structure are human loads, rain and wind. As such, the components which have
higher stress due to human loads and rain is the seating and the roof. To ensure
the stability of both parts of the structures, they are connected directly to the main
columns which are the tripod. This allows maximum stability for the seats and
roof. Since the roof covers a larger area, extra columns are places to support
towards the back of the roof, ensuring that is stable.
As for other loads such as wind load, it may cause a few problems such as uplift
and racking. However we have the designed the skeletal structure to have
minimal obstructions and to ensure air flow. This allows the air to pass through
the structure without causing a change in air pressure. Hence, without any
difference of air pressure, the uplift force causes by the wind is very minimal
The foundation and the large base area of each set of column also prevents the
structure from racking. The large base area is further made stronger by tying
down the columns to the foundation. Hence, the structure is able to withstand
racking from both ways.
The parts that bear the live
loads are directly connected
to the main columns
Live load: rain, wind
Live load: human load
Live load decreases as they
proceed downwards
Air flow
Uplift force is
minimal as air
flow is
ensured
Large base
area prevents
structure from
racking

15. 15
6.3 Structural Movement
In terms of structural movement, the structure is designed to move very minimal
as there shouldn’t be any moving parts. Therefore, several lateral ties function to
tie certain columns together, ensuring that they do not move.
The columns of the tripod are bounded by gyn lashings and are very stiff towards
the joint but the lower parts of the columns are vulnerable to movement. Hence a
triangular ground beam acts to hold them in place as the ground beam is tied and
bracketed to the columns. At the same time lateral ties help to resist the columns
from the tension of falling apart as well.
Other elements such as the roof trusses and beams located towards the back of
the structure also help to keep the both sets of columns tied together, increasing
the tensile force of the structure and minimizing any movement to the columns.
7.0 Conclusion
As a conclusion to our structural design, we have designed it to be of minimal
movement but with also a slight tolerance to certain stronger forces. This allows
the structure to be not too rigid as it is able to have tolerance towards forces,
hence avoiding any damage to the structure. In addition, the joints and
connections are sufficient to keep each element in place and are able to
withstand strong forces. With a properly designed structure and well-connected
joints, this skeletal structure for a bus shelter is a successful design.
Beams that act as lateral ties.

16. 16
8.0 References
1. Bamboo as a building material. (n.d.). Retrieved May 09, 2016, from
http://bambus.rwth-
aachen.de/eng/reports/buildingmaterial/buildingmaterial.html
2. Mechanical Properties of Bamboo. (n.d.). Retrieved May 09, 2016, from
http://www.guaduabamboo.com/facts/mechanical-properties-of-bamboo
3. Chinese Ink Painting Of Bamboo Drawing [Online image]. Retrieved May 9,
2016 from http://www.danaspah.top/chinese-bamboo-drawing/
4. [Untitled illustration of plastic bottles]. Retrieved May 9, 2016 from
http://www.womenshealthmag.com/weight-loss/plastic-recycling
5. [Untitled illustration of bolts and nuts]. Retrieved May 9, 2016 from
http://lloydsinfrasystems.com/products/
6. Corner Metal Bracket [Online image]. Retrieved May 9, 2016 from
http://www.indiamart.com/metaltech-engineering-nagpur/metal-
brackets.html
7. SupaChip Screws [Online image]. Retrieved May 9, 2016 from
http://screwcapsuk.com/products/14/supachip_screws.aspx
8. Square Lashing [Online image]. Retrieved May 9, 2016 from
http://bsar.org/book/export/html/193