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Collapse-Bay Bridge Essay

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On October 17, 1989, an earthquake hit San Francisco, California, killing at least fifty people and injuring several others. This earthquake registered as a 6.9 on the Richter scale, the largest since 1906. Not only did this earthquake devastate numerous families’ homes, it also collapsed the Oakland Bay Bridge. The damage due to the earthquake resulted in a cost of around ten billion dollars. The top section of the bridge collapsed, leading to a massive. To prevent similar disasters in the upcoming few decades, engineers launched an effort to upgrade other bridges in the area. Scientists say there is a possibility of another earthquake similar to Loma Prieta, the earthquake in 1989, in the next fifteen years. The key difficulty engineers reflected upon was the …show more content…

No design is perfect. The Oakland Bay Bridge consisted of two eight-mile long, suspension bridges. C. H. Purcell first built it in the 1930’s. According to Britannica Online, he originally had structural issues with the sinking to bedrock in the central anchorage. When repairing the bridge after Loma Prieta, the challenge was making it more seismically sound. The West Span of the bridge held up due to its suspension design. This led to the West Span being more flexible than the East. Bridges must have a certain level of flexibility, but not so flexible that extreme conditions would create another disaster such as the Tacoma Narrows Bridge Collapse of 1940. The West side of the bridge was mostly in tension when the earthquake hit. Allowing the bridge to absorb forces and create equal and opposite forces of its own kept the West side of the bridge intact. However, the stiffness of the East Span of the bridge was too stiff to handle the brute force of the Loma Prieta earthquake. Having flexibility in a design allows for the bridge to react to outside forces. Being too rigid would give necessary allowance for certain

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