THE UNIVERSITY OF MELBOURNE

Constructing Environments

Log Book

Name : Trishya John

Student ID Number: 699579

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Week 1 – Introduction to Construction

Knowledge maps

Loads on buildings (Ching, 2008)

Structural forces (Newton, 2014)

2

Materials (Newton, 2014)

3

Site Analysis

(Ching, 2008)

4

Theatre Session

We were introduced to the concept of loads on buildings in our first theatre session where we

were given a single sheet of blank A4 paper and tape and asked to build a structure that can

support a brick using only those materials. I formed a four point structure as shown below, which

I strengthened by folding repetitively. I was unable to test the structure at the lecture, so I

performed a test once I got back home by checking if the paper structure was able to support the

load of all my textbooks.

It was able to support my textbooks when the

thicker side of the structure made contact with

the ground, but not when the thinner side made

contact with the ground. One of the things that I was able to learn from this experience was that

it was crucial for a structure to have a very strong base in order to support an immense load. I

also realized that one of the reasons why my structure was successful was because the

symmetrical shape of it may have enabled an even distribution of the load of the textbooks

throughout the structure. These were some of the key elements that I tried to apply to our

structure that was built during the studio session.

Shape allows an even

distribution of the load of the

textbooks throughout the

structure

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Studio Session

Construction procedure

In our first studio session we were divided into groups of 3 and given blocks of the same size and

shape made of MDF. As this was a compression challenge, blocks were an efficient building unit

as blocks are commonly used in structures that rely on compression forces, such as arches. We

were then told to make a tower as tall as possible that could accommodate a toy horse provided

by our tutor, which meant that we had to integrate an opening into our structure. Our first step

was to measure how high the opening had to be for the object to be able to enter the structure,

and we did so by stacking the blocks one on top of each other next to the horse until they were a

bit taller than the horse.

However, we then realized that constructing the

tower by placing the blocks as shown on the left

would result in a structure that was very likely to

collapse due to its instability, so we then decided to

place the blocks flat on top of each other as shown

below. We then had to re-estimate the height of the

horse using the height shown in the image on the

left.

Estimating height of the object

Re-estimating height of the object

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We then decided to slightly change the laying of the blocks and place them the conventional way

bricks were laid in a building instead of merely stacking them one on top of each other. This

would have been more stable than originally planned, as the load from a block will be transferred

to two bricks below it instead of just one and thus be spread out more evenly.

We then started to build the structure

as shown below. Our aim was to pack

the blocks as tightly as possible in the

first ten rows to create a stable base

and then decide on how to change the

way the blocks were laid once the

structure gained a reasonable height.

Packing the blocks tightly together will

result in more blocks being laid at the

base, which then increases the

compression forces, causing the blocks

to be compact. This is what will ensure

stability for the whole structure.

Original block laying technique Modified block laying technique

Foundation of the structure

Aimed height of the opening

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However, this layout of the structure had to

be changed once again. This was because

the object had to be rotated once it was

inside the building in order to make it fit

inside the structure. Therefore, there was a

risk of the structure collapsing if we rotated

the horse while sending it into the opening.

We then decided to remove the blocks from one side of the structure to form an opening as

shown below and covered the gap made in the original building. This would then resolve the

issue of the object being able to enter the structure without having to be rotated.

Details of the block laying

technique – high compression

forces due to tightly packed blocks

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Even though we had now developed a

structure that could accommodate the object,

we still faced the issue of bridging the gap

created in order to form a doorway. We

attempted to stack the blocks in a ‘staircase’

manner on either side, but the blocks fell after

about two or three of them were placed, due

to the increasing load and the inability of the

blocks to support them, so we were unable to

create a bridge as the gap was too wide.

Our next idea was to warp the structure in order

to bring the gap closer so that a fewer amount of

blocks would have to be used in order to form a

bridge.

We attempted to bridge this much smaller

gap by stacking the bricks in a similar

manner to before, but unfortunately we were

unsuccessful again. As we could not make

the gap smaller, we decided to focus on

making the structure as tall as possible. Due

to the limit on the amount of MDF blocks

we were given, we decided to use less blocks to build the rest of the structure. I was able to

conclude that due to the fact that the blocks were packed tightly for approximately twelve rows,

the base would be strong enough to produce a stable structure that was capable of supporting a

heavy load. I based my conclusion on the paper structure I made in lecture 1, which was thick at

the bottom due to the folds, and thus was able to support the weight of all my books. We then

continued to lay the blocks on the structure, but left large gaps in between so that we would be

Attempt at

building a bridge

Modified layout to

accommodate object

Warping structure –

decreases compression

forces at base

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left with more blocks to add height. As the blocks are now spread out towards the top, the

compression forces of the structure decrease with the height.

Figure 1: Increasing the height of the structure

We completed our structure by following the

same pattern established previously.

Deconstruction procedure

Figure 2: Structure during deconstruction process

We were then told to remove blocks from the

structure one at a time in order to test the

stability of the building. In the process, I was

able to find a method to create a doorway.

Although we had considered this idea before,

we did not think it would work as we

assumed that the structure would collapse,

and we only realized that it would have

worked during the deconstruction process. I

simply removed all the blocks in one area

and created a large gap, as seen on the left.

The fact that our structure did not collapse even though all those blocks were removed indicates

that the loads were transferred through the structure in a manner that was able to prevent the

Compression decreases with height as

blocks are spaced widely

Final structure

Doorway – did not collapse due to

distribution of loads through the structure

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structure from collapsing. It is possible that our structure may have been able to support a

heavier load, if it had remained in a rectangular shape. This final structure may have encountered

difficulties with doing so because warping the structure pushed the blocks out of proportion in

the base, which may have reduced the compression forces that would have been much stronger if

the blocks were packed tightly together.

Figure 3: Load path diagram of structure with a few blocks removed

Figure 4: Comparison of compression forces between original structure and warped structure

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Comparison with other groups

This group had built a structure that was most

similar to ours in terms of the way they laid

the blocks, and the fact that they packed the

blocks tightly for the first few rows and

incorporated gaps in the higher rows. The

only differences were the shape of the

building and the fact that they had managed

to successfully integrate a doorway into their

structure.

This was another structure created by one of

the groups, which had a very different block

laying technique and shape compared to the

structures of the other groups. It seems as

though their technique of laying blocks,

although aesthetically appealing, may have

used a relatively larger amount of blocks

compared to the conventional brick laying

technique that all the other groups adapted.

Even though their structure was able to

accommodate the object, they too appeared

to be unsuccessful in bridging the gap.

Strong compression forces enabled

structure to support a load of over

5kg, which was done near the end

of the studio session

The blocks are packed tightly

together, which will increase the

compression forces in the structure

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Although the block laying technique is not

very visible in this photograph, it appears

that they adopted a similar method to our

structure. However, it appears that they

might have encountered difficulties during

the construction process as they too were

unsuccessful in creating a doorway, and

were not able to create a tall structure. The

blocks appear to be packed tightly together

and they have followed this method to

create the entire structure, which means that

the compression forces will be high.

Week 2 – Structural Loads and Forces

Knowledge maps

Structural systems

(Newton, 2014)

Structural joints

(Newton, 2014)

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Common Environmentally

Sustainable Design Strategies

(Newton, 2014)

Building systems

(Ching, 2008)

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Theatre session

We covered the importance of how trusses and a bracing system are key elements in supporting

loads in various structures. This was illustrated by various students having to build a truss on a

plastic cup with straws which had to be attached to the cup with pins. These are diagrams of two

structures that were made during this exercise, one which was successful and one which was not.

This structure was able to support

a load effectively because bending

the straws provided 8 paths for the

load to be transferred to the

ground. Folding also provided a

much shorter distance for the loads

to travel, and ensured structural

stability.

This structure was unable to

support a load because the long

straws were unable to support a

load easily, which caused the

whole structure to collapse. There

were also only four paths for the

load to be transferred.

Successful structure

Unsuccessful structure

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The unsuccessful structure can be improved by introducing a bracing system as shown in the

figure above. The system is in the shape of triangles, which is a difficult shape to distort, and

therefore adds more stability to the system. It also provides more paths for the loads to be

transferred to the ground.

The concepts illustrated in the lecture were useful for the frame challenge in the studio session,

as they illustrated the different ways in which long, thin members could be used to effectively

carry and transfer loads.

Studio session

Construction procedure

This week’s studio introduced the concept of a frame structure, and to illustrate this, we were

told to build a frame tower out of only 20 strips of cut balsa wood in groups of 3. The tower had

to be as tall as possible, and we were encouraged to experiment with different types of joints. We

were told that the towers would have a load placed on it once they were completed to see at

which points they fail. Balsa wood was an efficient material for this challenge as the strips were

light and had a low density, which are properties that would have been needed to make a frame

structure. In order to save strips of balsa wood, we decided to make the tower in the shape of a

triangle instead of a square or rectangle. We cut 3 pieces of wood, of 20cm each, and used them

to form an equilateral triangle for the base. Then, we joined three strips of wood to each of the

corners of the triangle.

How unsuccessful structure can be

improved

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We then cut a second triangle with sides

measuring 20cm and joined it with the three

strips of wood that were stuck onto the first

triangle.

The strips of wood were joined together

by masking tape, which, in the context

of this structure, can be considered a

fixed joint. A fixed joint resists rotation

and translation in any direction, and

provides force and moment resistance

(Ching, 2008), and as the structure was

relatively stable with an additional

successive level, we decided to

continue using fixed joints.

Sketch of structure we

wanted

Foundation of

structure

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However, as the structure began to increase in height, we

found that we had to add pins to the joints, thus creating pin

joints, along with the fixed joints, as strips of joined balsa

wood kept detaching, which suggested that just fixed joints

were not strong enough to hold the members together. We

joined the strips of wood with a pin, and then wrapped the

pin with masking tape.

Fixed joint

Details of fixed joint

Structure is stable but a

slight tilt can be observed

due to weak joints

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Although we assumed that our

combination of pin and fixed joints

were strong enough to keep the

members in place, the tower began

to twist and lean as it increased in

height, possibly due to the

increasing load of the structure.

This was an indication that perhaps

the joints may have not been

efficient enough to transfer the

loads, possibly due to the way we

had attached the members. The

manner in which forces are

transferred from one structural

element to the next and how a

structural system performs depends

on the types of joints used, to a

large extent (Ching, 2008). The addition of the pin may have also caused the member to fold

backwards, based on the way we attached it, which may have also been a factor in causing the

structure to twist because the joints were not stable enough to transfer the loads.

The members were also

rectangular in shape, which

results in uneven distribution

of the load through the strips

of balsa wood. This would

have also been one of the

factors that caused the

torsion of the member,

resulting in the whole

structure twisting. If the

members were in the shape

of a square, there would have

been a more even

distribution of the load,

resulting in less torsion.

Details of pin joint

Load through individual members

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As seen in this diagram, each joint will be connected

to three members and will thus receive loads in three

directions. If the joint is ineffective in transferring

these loads, the whole structure will be unstable.

Due to the structure twisting and bending as a result of

the joints failing, there came a point where the

structure was unable to stand without support because

it was unable to transfer the load effectively

throughout the structure, which resulted in it being

unable to support the load of the additional members.

This explains why the final structure was unable to

stand

without

support

Our idea was to form a bracing system in order to

prevent the members from twisting, so we cut a strip

of balsa wood and connected it to two of the

members that were twisting the most. However, it

did not fix the problem since the twists were due to

the joints, so we did not continue developing a

bracing system.

Load path

diagram of

structure

Attempt at

bracing

structure Lean in the structure can be

observed clearly due to the

increasing load

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We finally added 3 more members to the 3rd triangle (excluding triangle made for the base) and

joined them at the ends. These are images of the final structure which was, as seen below, unable

to stand without being supported.

Deconstruction procedure

The structures then had a load applied to them, in order to estimate at which points they started

to fail.

Figure 5: Deconstruction procedure

As seen in the picture, the structure was bending

at the joints when a load was applied. It was

mentioned before that the purpose of a fixed joint

was to prevent rotation of the members, but ours

failed to do so because we connected the

members incorrectly. This was why the structure

was bending at the joints.

Structure without a support

system

Point at which

structure was

unable to support

itself

Structure with a

support system

Bending occurring at the joints

when a load is applied – joint

should have resisted load

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As the load increased, one of the members

that were joined at the second triangle

snapped at its mid-point. This was because

the increasing load was causing an increase

in the reaction force that was acting on the

member. The two forces met at the middle,

which then caused the structure to snap at

that point.

Load path diagram of a section of

structure during deconstruction

process

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Comparison with other groups

All of the structures built by the other groups had a member snap at its mid-point when a load

was applied, due to the explanation given. However, as seen below, the members did not bend at

the joints the way they did in our structure, because they consisted of more effective joints.

Less bending occurs at the

structural joints when a load is

applied – only the individual

members bend. Structures all

displayed a bracing system that

would have reinforced the overall

stability.

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Glossary of Terms (Ching, 2008)

Beam – rigid structural members designed to carry and transfer transverse loads across space to

supporting elements.

Brace - A diagonal tie that interconnects scaffold members (WebFinance Inc, 2014)

Carbon footprint – measure of the amount of greenhouse gases generated during the

fabrication, transportation and use of a particular product

Columns – rigid, relatively slender structural members designed primarily to support axial

compressive loads applied to the ends of the members

Collinear forces – occur along a straight line, the vector sum of which is the algebraic sum of

the magnitudes of the forces, acting along the same line of action

Compression forces – an external load pushing on a structural member, resulting on the

shortening of the material (Newton, 2014)

Concurrent forces – have lines of action intersecting at a common point, the vector sum of

which is equivalent to and produces the same effect on a rigid body as the application of the

vectors of the several forces

Dead loads – static loads acting vertically downward on a structure, comprising the self-weight

of the structure and weight of building elements fixtures and equipment firmly attached to it

Dynamic loads – loads that are applied suddenly to a structure, often with rapid changes in

magnitude and point of application

Fixed joint – maintains the angular relationship between the joined elements, restrains rotation

and translation in any direction, and provides both force and moment resistance.

Frame – an assembly of vertical and horizontal structural members (WebFinance Inc, 2014)

Impact loads – kinetic loads of short duration (moving vehicles, equipment and machinery)

Live loads – any moving or movable loads on a structure resulting from occupancy, collected

snow and water, or moving equipment

Load path – the route a load takes through a structural system to reach the ground

Masonry – building with units of various natural or manufactured products, usually with the use

of mortar as a bonding agent

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Non-current forces – have lines of action that do not intersect at a common point, the vector

sum of which is a single force that would cause the same translation and rotation of a body as the

set of original forces

Occupancy loads – result from the weight of people, furniture, stored material and other similar

items in a building

Pin joints – allow rotation but resist translation in any direction

Point load– A concentrated load in a specific position on a structural member (WebFinance Inc,

2014)

Rain loads – accumulation of water on a roof because of its form, deflection, or the clogging of

its drainage system

Reaction force – equal and opposite forces that resist an applied force

Recyclability – potential for a product / material to be reused or transformed into a new product

Roller joints – allows rotation but resists translation in a direction perpendicular into or away

from their faces

Site analysis – the process of studying the contextual forces that influence how we might situate

a building, lay out and orient its spaces, shape and articulate its enclosure, and establish its

relationship to the landscape

Snow loads – created by the weight of snow accumulating on the roof

Static loads – loads that are applied slowly to a structure until it reaches its peak value without

fluctuating rapidly in magnitude or position

Stability – the measure of the ability of a structure to withstand overturning, sliding, buckling or

collapsing (WebFinance Inc, 2014)

Structural joints – connectors used to joint structural elements

Tension forces – external load pulling on a structural member, causing the material to elongate

(Newton, 2014)

Wind loads – forces exerted by the kinetic energy of a moving mass of air, assumed to come

from any horizontal direction

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References Ching, F. D. (2008). Building Construction Illustrated (4th ed.). Hoboken, New Jersey : John

Wiley & Sons.

Newton, Claire (2014). Introduction To Materials. Constructing Environments.

Newton, Claire (2014). Basic Structural Forces. Constructing Environments

Newton, Claire (2014). Structural Systems and Forms. Constructing Environments

Newton, Claire (2014). ESD And Selecting Materials. Constructing Environments

Newton, Claire (2014). Structural Connections. Constructing Environments

WebFinance Inc. (2014). Dictionary of Construction.com. Retrieved March 15, 2014, from

http://www.dictionaryofconstruction.com/