【作者】 陈来云；

【导师】 蒋通；

【作者基本信息】 同济大学 ， 防灾减灾工程及防护工程， 2008， 硕士

【摘要】 复杂场地的土层地震反应分析对结构的地震反应和抗震安全性评价具有重要意义,是当前地震工程和岩土工程研究的一个重点也是一个难点,其涉及的因素很多,涉及面很广。本文针对上海浦东机场二期航站楼大跨度结构所处古河道局部不规则场地,考虑了土层的非线性和地震动的空间相关性,采用有限元数值分析进行2维场地地震反应,对航站楼基础位置的输入地震动进行了分析计算,对不规则场地和空间相关地震动的影响进行了分析和评价。具体研究工作内容如下:1.首先从水平层状场地土层入手,叙述了基于波动理论的解析方法和有限元数值求解场地地表地震反应的方法。并对不规则场地地震反应现有研究成果及国内外抗震设计规范对场地条件的考虑做回顾与总结。2.对采用有限元进行2维场地地震反应分析时所涉及的有限元网格尺寸、土介质阻尼矩阵形成、人工边界设置等问题进行探讨并建议了处理方法。通过ANSYS数值分析,对于各层土介质为均匀线弹性体的水平层状土层,通过在不同频率谐波作用下求得的数值解与波动理论解析解进行比较,验证上述几个问题处理的有效性。为应用ANSYS参数化语言(APDL)考虑场地的非线性和空间相关地震动的多点输入的分析做好准备。3.用ANSYS建立航站楼场地FEM模型并进行地震反应分析。为了探讨不规则地形的影响,将2维分析结果与水平层状土层假定下的1维场地模型地震反应分析结果进行比较。并进行了地震动水平一致输入、水平加竖向一致输入和空间相关多点输入不同工况下的场地地震反应分析,以考虑地震动的空间相关性和水平与竖向地震动的相互作用,并分析对比了各种工况下地震动的特点。4.介绍用不规则地形地震动放大指标来简易评价倾斜基岩型场地地震反应的方法。结合浦东机场二期航站楼场地地震反应数据分析结果,对简易方法的可行性做出评价。更多还原

【Abstract】 It is of great importance to study seismic response analysis of complex topography for the seismic response of structures and the safety estimation of earthquake resistance. It is also a difficult research topic in the field of earthquake engineering and geotechnical engineering as concerning many influencing factors and involving wide research field. In this dissertation, as No. II Terminal of Shanghai Pudong International Airport locates on the irregular topography, the input motions for seismic response analysis of No. II Terminal structure are calculated by using 2D FEM model considering the nonlinear property of soil and the spatially correlative seismic motions. According to the results of FEM numerical analysis, the effects of irregular topography and spatially correlative seismic motions are evaluated. The research contents are as follows:1. Calculation methods for solution of ground seismic response are introduced, including analytical solution based on wave theory and FEM numerical solution. Then the previous research on seismic response analysis of irregular topography and the design specifications relating to site condition are reviewed.2. For 2D site seismic response analysis by using FEM, the dimension of finite element mesh, the form of damping matrix, the application of artificial boundary are discussed. Some corresponding suggestions for necessary calculation precision are put forward by comparing ANSYS numerical solution with analytical solution of linear elastic horizontal layered soils. As well as this, ANSYS is secondly developed by using ANSYS Parameter Design Language (APDL) including considering the nonlinear property of soil and the multi-input of spatially correlative seismic motions.3. The 2D FEM model of No. II Terminal site is established by using ANSYS. In order to discuss the effect of 2D irregular topography, the seismic response analysis of 1D model is processed. For indicating the influence of the spatial correlation of input motions, the horizontal uniform input, the horizontal and vertical uniform input, and multi-input are carried out for the site seismic response analysis. Then some characteristics of seismic ground motion calculated by above-mentioned cases are compared.4. A simplified method for site seismic response is introduced to consider irregular topography with amplification index. According to the numerical results of No. II terminal site seismic response analysis, the feasibility of the simplified method is proved.更多还原