2014-1_Hsin yeh wk1&2logbook

CONTENTS WEEK 1 - Introduction to Construction WEEK 2 - Structural Loads and Forces SUBJECT GLOSSARY

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WEEK 1

INTRODUCTION TO CONSTRUCTION

WEEKLY ELEARNING

THEATRE SESSION

Week 1 lecture was an subject overview of Constructing Environments, followed by an activity of building a strong structure out of a piece of paper. The activity showed the way a material is constructed has large influence on the load it is able to withstand.

Six topics, including loads, construction overview, materials, basci structural forces, load path, and Melbourne’s bluestone structure, were introduced in the week 1 eLearning. Each of these topics are further explored, as shown in the knowledge map, and their contexts are inter-connecting with one another. For example, materials relate to the isotropic or anisotropic properties when being compressed or tensed. Also, the economy and sustainability of materials and the use of blustone in Melbourne city share the same idea of using local materials in construction.

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STUDIO ACTIVITY: TOWER The studio activity was to build a tower as high as it can be, which would be able to fit in an animal model. The material is MDF bricks.

The first layer was built with the bricks standing on its length in order to have a higher construction. However, the tower would be unstable if the base only rest with small surface area. Therefore, from the second layer, the bricks are layed flat and rest with the most suface area.

As shown in figure 3, when the tower reached the forth layer, a brick in the first layer was rotated 90 degree and an additional brick was inserted from the side to support the end brick on the forth layer.

This construction was to create a entrance for the animal model to fit in.

The construction of the tower continues to repeat the previous process, which is illustrated in figure 4. Every four layers, a brick was inserted from the side to keep the entrance open.

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The plan view of the tower was a semi ellipse form, as shown in figure 5, with the arrow pointing the entrance.

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The loads of a brick were supported by the bricks below it at both ends, and the loads of these two bricks were transferred further down to the other bricks. As a result the entire tower was stablised by the compression between each brick. This is illustrated in figure 6.

When taking out a brick, the loads of bricks were transferred in a different way, and the tower was still stable. This is shown in figure 8. More bricks could be taken as long as the existing brick was compressed by the bricks above and supported by at leaset one brick below.

WEEK 2

STRUCTURAL LOADS AND FORCES

Week 2’s lecture included an activity of building a structure, which could withstand 500 grams to 1 kilogram of load, using few straws, pins, and a plastic container. Several students had participate in making one, and alterations were made to increase the load capacity of the structures. The knowledge map is a summary of the strategies that can strengthen the structure, which are learnt through the activity.

06 Week 2’s eLearning introduced the concepts of construction systems, structure systems, structural connections, and environmentally sustainable design (ESD). These topics link with each other in many ways.

The ideas of ESD buildings can be incorporated into the decision making of what type of structural system to be used for constructing a building. Structural system is an element in construction system, and there are many types of structures. Each of the structure type is then constructed differently by applying varioud structure connections. These concepts provide basic understandings of the method of construction and how to construct in a more sustainable way.

WEEKLY ELEARNING THEATRE SESSION

STUDIO ACTIVITY: FRAME The task of week 2 studio session was to construct a frame structure as high as it could and be able to withstand load.

able to relieve some load from the original posts, but due to the weak joints, they did not successfully increase the load capacity of the structure.

The frame structure from my group started with a wide triangular base, so the load would be spread across wider footing. There were also bracings between the three stripes of balsa wood to make the triangular base more stable.

Some bracings were also added between the long posts to strengnthen the structure.

The upper structure was built by three stripes of balsa wood connecting to the traingular base. One stripe per side.

These three posts were then held by another triangular frame, but smaller.

Then, three longer posts were connected to this second triangular frame, and held together on top by a third triangular frame.

However, after several supportive additions to the structure, it was only able to withstand the load of a sticky tape roll for few seconds before collapsing.

Image. 1, taken by Hsin Yeh Frame tower built by my group

At this stage, a load was placed on top of the structure to test its capacity. It was not stable as the posts were very long, the triangular frames that held the posts were quite far apart from each other.

Therefore, another three very long posts were added to the structure, connecting from the top to the bottom traingular base. These three posts were

weak joint, easily collapse

Image. 2, taken by Hsin Yeh Frame tower built by my group

The posts of the structure were too long and there were not enough horizontal support, such as the triangulat frames and the bracings, between the posts.

Also, the joint between the stripes of balsa wood were not strong enough to stablise the structure. Plus, the narrowness of the triangular frames held the posts too close to each other. Therefore, the loads pushed the posts inward easily. A wider distance between posts, stronger joints, and more bracings might make the structure stronger.

Image. 3

weak joint, easily collapse

Image. 4

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Image. 5 Taken by Hsin Yeh Frame tower built by group A

Image. 6

Image. 7 Taken by Hsin Yeh Frame tower built by group B

The other two groups constructed their frame towers in a similar way. They were both based on triangular frameworks made of three stripes per each triangle. These triangular frames were then connected to each other by one post at each point on the triangle (group A) or bracings between posts (group B). Group A also added supportive structure at the base, which created a wider and more stable footing. The load capacity of these two groups’ towers were greater than the tower of my group as the loads were transferred through the structure in a more widespread and balanced way, as shown in image 6 and 8. Their structures were more consistent and wide, therefore, were able to withstand heavier loads.

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Image. 8

SUBJECT GLOSSARY WEEK 1 Load Path A illustration of how load is transferred in a structure with arrows representing the force and its direction.

Masonry A type of construction where all elements, including load bearing or non-load bearing, are made of bricks, stones, marbles, and other materials that are compressed and solid.

Compression A situation when an object is pressed or pushed inward by exterior forces.

Compression often causes the object to be shortened.

Reaction Force A force reacting to an applied force. An object resting on the ground is the result of the ground releasing a force against the weight of the object.

The weight released from the ground is a reaction force.

Point Load A load that is localised to a specific location on a structure. This normally refers to a location with small area rather than a literally sharp point.

Beam A horizontal structure that support the load of a building or part of a structure. Such as a long piece of wood, metal, or concrete.

WEEK 2 Structural Joint A joining of materials, which is supportive or useful to a structure, using mechanical techniques.Examples are roller joint, pin joint, and fixed joint.

Stability A state or level of a structure’s quality in being stable.

Tension A situation when an object is pulled apart by exterior forces, and is often lengthened.

Frame A border or grid of skeletal materials, such as timber and metal, that outline the form of a structure.

Bracing A supportive element that links diagonally between beams or columns to reinforce the structure’s stability.

Column A long piece of material stands upright from ground to support roof, floor, or stand alone as a decoration.

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