PROBLEMS WITH THE EXPERIMENT

Index ~~ Background ~~ Purpose ~~ Hypothesis ~~ Materials ~~ Earthquake Machine ~~ Modifications: Overlapping - Height - Buttresses - Base Isolators - Cross Braces - Roofs ~~ Resistant Buildings ~~ Problems ~~ Further Experimentation ~~ Bibliography

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1. THE EARTHQUAKE MACHINE

The holes drilled in the bottom board didn’t match the position of the springs in the top board so all the springs couldn’t stand up straight when the top piece of plywood was put on. The testing surface was too small so it was covered with a larger piece of Styrofoam. The marble base isolator was too heavy for the springs and made the machine top lean slightly to one side. It was hard to pull the handles in the same way every time so that the machine would shake the same.

2. STRUCTURAL MODIFICATIONS AND BUILDING STABILITY

a) Overlapping and Stability -The blocks couldn’t be attached together because then the buildings wouldn’t fall when being tested on the earthquake machine. The only way it was possible to do this experiment was if the blocks were not attached to each other. This meant that buildings could only be stabilized to a certain point.

b) Height and Stability - There were no problems with this experiment except it would be good to see what happens to buildings with more layers.

c) Buttresses and Stability - Using the blocks as buttresses, it was only possible to put buttresses on the first three layers of the buildings. Stacking more blocks to make a higher buttress didn't work. It toppled over. This left the top layers without a buttress.

d) Base Isolators and Stability - As mentioned above the marbles were too heavy for the machine causing it to bend over slightly to one side. Larger buildings such as a cross were too heavy to be placed on the marble base isolator at all because it would be too heavy for the machine. Many lighter substitutes were tried, such as peas, beads and Styrofoam balls but they all had their own problems.

e) Roofs and Stability - The roof couldn’t be attached well enough to the rest of the building, so after a couple of shakes of the earthquake machine, it just fell off especially since the rest of the blocks in the building weren’t attached. The roof needs to be attached to the rest of the building to make sure the building stays together during an earthquake. If the roof starts to fall off, gravity and the forces of the earthquake could topple the building.

f) Cross bracing and Stability - It was hard to find the right materials to make the cross braces and to fit the cross braces into the buildings. It was also difficult to attach the cross braces to the blocks. In some trials the building and the cross brace fell over because they weren’t attached to the earthquake machine well enough.

Nine layer building with overlapped blocks but only three layer buttresses