Analysis of Increased Shears and Overturning Moments in Structures by Ground Rocking During Loma Prieta, October 17,1989 Earthquake

这是1989年10月洛马普列塔地震后的一个调查项目，旨在从这次破坏性事件中吸取教训。本课题的主要目的是研究地震震动对结构反应的影响。地面运动的摇晃分量通常被认为量级很小，因此其影响被忽略了。然而，在某些情况下，结构、场地位置和地震运动的综合条件使得摇晃分量变得重要。在这个项目中，将研究损伤分布，以确定在设计时没有考虑到这些额外影响的摇晃运动对建筑物的损害。将利用整个湾区的地质和土壤数据，根据记录的平移运动估算不同地点的摇摆运动贡献。生成的数据将用于分析不同结构的摇摆响应。这项研究将使工程师能够合理地确定在考虑或不考虑这种额外地震力的情况下，摇摆运动在结构抗震安全设计中的重要性。

This is a post Loma Prieta earthquake (Oct. 1989) investigation project in learning from this damaging event. The gist of this project is to study the effect of rocking motion of the earthquake to the structural response. The rocking component of ground motion is generally considered to be small in magnitude and therefore its effects are neglected. There are however certain situations where the combined conditions of structures, site location, and earthquake motions are such that the rocking component becomes important. In this project, the damage distribution will be studied to determine where the rocking motion contributed to the damages of the buildings which were not designed to account for these additional effects. Geology and soil data of the entire bay area will be used to estimate the rocking motion contributions at various sites based on the recorded translation motions. The generated data will then be used to analyze different structures for rocking response. This study will enable engineers to determine rationally the importance of rocking motion in the seismic safety of structures designed with or without consideration of such additional earthquake forces.