【作者】 施正城；

【导师】 陈文化；

【作者基本信息】 北京交通大学 ， 桥梁与隧道工程， 2010， 硕士

【摘要】 随着我国经济的高速发展,我国已经进入了地铁工程建设的黄金时代,然而到目前为止还没有独立的地下结构抗震设计规范,相比日本和美国等发达国家,我国在地下结构抗震领域的系统研究尚不够成熟。加上近年来我国已进入地震频发期,在这种大背景下,如何保证在地震作用下地铁结构的安全成了我们迫切需要研究的课题。研究软土地基城市地铁车站与区间隧道过渡段的抗震设计规范具有重要的意义,本文对地铁地下特定部位结构的动力响应进行时程分析,本文的主要内容包括：(1)介绍国内外关于地铁抗震的分析方法以及各种方法的使用范围；(2)通过对土-地下结构体系的动力相互作用数值解法的剖析,提出解决地下结构抗震分析的理论依据；(3)利用有限元软件MIDAS建立地铁车站与区间隧道过渡段的三维数值模型,人工边界采用粘性边界；(4)以1995年日本HYOUGOKEN_South的加速度时程记录为地震输入波,我们分别考虑三种情况,分别是地铁车站与区间隧道的剪切刚度之比在k1=0.8α,k2=α, k3=1.25α(α为截面尺寸影响系数)的时候,在地震荷载下的动力时程响应；(5)分析三种不同情况下过渡段上不同位置的位移、速度、加速度及应力、应变的时程图,得出地铁车站与区间隧道过渡段的动力响应规律；(6)刚度的增大能有效增强结构抵抗地层变形的能力,但却会造成应力集中,结构内力和应变增大,对局部受力不利。因此需要改变仅通过增强结构刚度或者强度来提高地下结构的抗震性能的传统观点。在进行地铁车站结构的抗震设计的时候,可以考虑适当增加结构的韧性,这样地下结构在地震中就会具有一定变形能力,以此承受地震引起周围土层介质变形产生的应力,而不是盲目地使结构直接抵抗地层的变形；(7)在考虑过渡段结构的抗震问题时,应首先满足结构本身的设计强度和刚度,然后再考虑尽量减小过渡段的刚度变化,即k值尽量的小,以避免造成过渡段的应力集中和应力过大。本文对进一步研究软土地基上城市地下结构对地震作用的响应具有一定的参考价值。更多还原

【Abstract】 With the rapid development of our economic, it can be said that the gold period of the subway-construction is coming in our country, but there is no independent underground structures anti-seismic design rules so far. Compared to Japan and America and other developed countries, our studies in the field earthquake-resistance of underground structures are still immature. How to keep the subway safe in the earthquake has become an urgent need for research topics in the context of our country has become quake-prone. It has great significance to research the structure between the subway station and the running tunnel design rules of the vibration under soft soil. This article analyzes the time history analysis of the specific parts. The main contents include:(1) Introduce the methods about researching the subway vibration;(2) Studying the numeral method of the interaction between the earth and the underground-structure, to give the theory to solve the vibratory problem;(3) Build the three-dimensional numerical model under earthquake by using the finite element software-MIDAS. The model adopt viscous-elastic border;(4) The strong earthquake record, which is recorded in HYOUGOKEN_South in Japan in 1995, when the earthquake occurred, is selected as the bedrock input ground motion. We consider three cases, when k is different (k is ratio of shear rigidity). Compare the response characteristics of the subway station;(5) Analyze the data of different locations for specific parts of displacement, speed, acceleration, stress and strain as flowcharts in three different circumstances, and then come to the dynamic response law of the part that between the subway station and the running tunnel;(6) The stiffness of increase can strengthen the ability to resist the structure of shape effectively, but it can cause the concentration of stress and strain. Therefore, we should change the traditional views that improve the structures anti-seismic by increasing structural stiffness. When faced with the vibration design of the subway, we can consider increasing the toughness of the structure so that the structure in the earthquake will have a certain ability to take shape by the earthquake caused the surrounding soil medium of stress and deformation, but not to against deformation of the ground directly; (7) When encounter the vibration problems of the transition section, in order to avoiding the stress concentration, we should firstly meet the need of structure itself designed to strength and stiffness, and then to reduce the change of stiffness of the transition section.This article is reference value in further research of the underground structures foundered on soft soil.更多还原