饱和土中地铁车站的地震响应分析

【作者】 周巧芳；

【导师】 赵成刚；

【作者基本信息】 北京交通大学 ， 岩土工程， 2008， 硕士

【摘要】 兴建地铁是解决城市交通堵塞和环境污染问题的最为有效的手段之一,但在地铁设计与建设过程中还有一个重要问题没有解决,这就是地铁车站的抗震问题。值得注意的是许多地下铁道结构所处地区都位于地震频发地带,因此地下铁道结构的抗震设计和抗震安全性能评估是个必须面对的问题。地铁车站是地铁运营过程中的交通枢纽,使用周期长、人员集中,一旦遭到地震破坏,可能造成重大人员伤亡和车站结构的损伤。除了修复工作比地上建筑物困难外,所带来的间接经济损失远大于直接损失,一般也远大于地面结构的经济损失,并且也会给社会生活造成重大影响。这些都迫切要求人们对地下结构的抗震问题有更新的认识,并对地下结构的抗震问题加强研究。本论文在廖振鹏和赵成刚等分别建立的单相介质和流体饱和两相多孔介质动力分析的显式有限元方法的基础上,建立了适用于地铁车站结构—饱和土体耦联系统地震响应分析的模型,并编写了适合于饱和土与地铁车站结构耦联系统的地震动响应分析的程序,数值计算给出了地铁车站结构的平面P波的地震动响应,分析并讨论了地铁车站的埋深、结构厚度、场地土性质、车站结构高跨比、结构类型等因素对地铁车站结构地震动响应放大系数的影响。通过对计算结果的分析和比较,发现:地铁结构的最大位移多发生在顶板和侧墙上,这与阪神地震中的地铁车站破坏位置一致;浅埋地铁车站的埋深对于其抗震性能有很重要的作用;对于浅埋地铁车站结构来讲,在厚度较小的范围内,增加结构厚度会使地铁车站的地震响应位移峰值随之增大;地铁车站的结构形式对于其抗震性能也是非常重要的,在相同的跨度和相同的高度情况下,增加结构跨数能明显的提高抗震性能。上述研究成果对建立和完善的软土层中地铁车站抗震设计方法具有参考价值。更多还原

【Abstract】 The construction of the subway is one of the most effective means to handle the urban traffic congestion and the environment pollution, but there is an important problem which is not solved in the design and construction of the subway. That is the subway station seismic problem. It is worth noting that many metro areas are located in the structure in the frequent seismic zone, so the seismic design of the structure of Mass Transit Railway and performance evaluation of seismic safety is a problem that we have to face.Subway station is a transport hub with a long life cycle and the concentrated crowd. Once the subway station is damaged by the earthquake, may result in significant casualties and damage to the structure of the station. But the restoration work is more difficult than the general structure on the ground, and the indirect economic losses is far greater than the direct losses, as well as there will be a significant impact on the social life. Thus, it is very urgent that people must have some update understanding of the seismic problem of the underground structures, and we have to do more research on the seismic ability of the underground structures.In this paper, on the basis of the explicit finite element method of the single-phase medium and two-phase porous fluid-saturated medium dynamic analysis, which was established by Liao Zhen peng and Zhao Cheng gang, I established the finite element model applicable to the earthquake response analysis of the subway station structure -fluid-saturated soft soil coupled system. By using this model, I made a program to analysis the earthquake response of the subway station structure in saturated soil, and the numerical results were given to illustrate the earthquake response of the subway station for the plane P waves. I did some research on the earthquake response displacement enlarged coefficient of the subway station structure under some different conditions, such as the burying depth of the subway station, the thickness of the structure, the properties of the ground soil, the structure types. The conclusions have some referential value for the establishment and improvement of the seismic design method of the subway station in soft soil.更多还原