Earthquake Deformations of Subway Infrastructure

9714859 Lee在美国或世界其他地区的大多数大都市地区，已经或正在计划拥有地下基础设施系统作为城市交通的替代方式。 重要的是要了解与地下建筑相关的损害的特点，并找出岩土工程以及结构变形的原因，也要研究在结构附近的局部场地效应的影响，对结构的变形放大所产生的强震运动。 以往地震的经验表明，在某些地区记录到的运动幅度大于预期。 这些地区通常有很深的冲积沉积物，表面附近有相对较软的土壤沉积物。 大规模的民用基础设施（水坝、高速公路网、桥梁和现在的地下地铁）对强烈地震地面运动的反应高度依赖于当地的地表和地下地形。 本项目旨在研究地铁、多结构基础和当地地质之间的相互作用的影响，以探索所有这些关键因素如何影响基础运动的放大。 所提出的方法是基于弹性固体介质中的波传播。 在解决问题的挑战将是在边界条件的非正交的压缩和剪切潜力耦合。 这将克服扩展系列和波势的积分表示。 这些研究的结果将与以往地震记录的实际变形进行比较。 这些比较将作为指导方针，以正确模拟所考虑的问题。 通过正确理解地表（建筑物和高速公路）和地下（地下地铁）结构在强震动地震中的表现，未来新建筑的结构设计和现有结构的改造计划可以通过包括这些局部场地效应来改进，以提供正确的设计强度和钢筋。 然后，它将有助于减少财产损失和生命损失，在未来的地震来。 ***

9714859 Lee Most large metropolitan areas here in the United States, or countries in other parts of the world, already have or are planning to have underground infrastructure systems as an alternate way of urban transportation. It is important to understand the characteristics of damages associated with the underground construction and to find out the cause of both geotechnical as well as structural deformations, and also, to study the influence of local site effects in the vicinity of the structure on the amplification of structural deformations resulting from strong earthquake motions. Experiences from previous earthquakes suggest that the recorded motions in some areas had larger than expected amplitudes. These are usually areas with large depths of alluvial sediments together with comparatively soft soil deposits near the surfaces. Massive civil infrastructures (dams, freeway networks, bridges and now the underground subways) respond to strong earthquake ground motions that are highly dependent on the surface and subsurface topographies at the local sites. This project is to study the effects of the interactions among the subways, the multiple structural foundations and the local geology, to explore how all these key elements will affect the resulting amplifications of foundation motions. The proposed method is based on the wave propagation in elastic solid media. The challenge in solving the problem will be in the boundary conditions where the nonorthogonal compressional and shear potentials are coupled. This will be overcome with expanded series and integral representations of the wave potentials. Results from these studies will be compared with the actual deformations as recorded from previous earthquakes. The comparisons will serve as guidelines to the correct modelling of the problem under consideration. With proper understanding of how surface (buildings and freeways) and subsurface (underground subways) structures performed during str ong-motion earthquakes, future structural design of new buildings and retrofit plans for existing structures can be improved by including these local site effects to provide the correct design strength and reinforcement. Then it will help to minimize property damage and the loss of life in future earthquakes to come. ***