【作者】 丁浩；

【导师】 薄景山；

【作者基本信息】 中国地震局工程力学研究所 ， 岩土工程， 2008， 硕士

【摘要】 场地条件对地震动的有着显著的影响。近十年来,作为场地条件的一个重要内容的土层结构对地震动的影响受到了人们的普遍关注。由于土层的复杂性,在工程抗震研究领域,人们从不同的角度来研究土层结构对地震动的影响。本文借助于传递函数的概念研究已知基岩输入情况下,不同土层结构对地震动“放大作用”的影响,并利用放大倍数具体表述。传递函数是频域分析中的一个重要概念,它严格的数学概念是针对线性系统在已知输入和传递函数的情况下,求解系统的输出。在岩土工程抗震领域内,人们借助传递函数的概念,研究非线性系统输入和输出的关系。在给定地震动输入的情况下,研究对地震动有影响的场地条件,进而了解场地对地震动的放大作用,这一方面的研究是当前岩土工程抗震领域的重要内容之一,有重要的理论和现实意义。本文利用土层地震反应分析的等效线性化方法,借助传递函数的概念,重点研究了土层结构对输入地震动的“放大作用”这一问题,完成的主要工作如下:1.简要总结了场地条件对地震动影响研究的国内外现状,详细介绍了土层结构对地震动影响研究的若干进展,对有关问题进行了详述和讨论。2.介绍了传递函数概念和其在岩土抗震研究中的应用。详细介绍了土层地震反应分析一维等效线性化方法。具体介绍了传递函数在这一方法中的具体实现,对具体的计算程序进行了详细分析和解读。3.在课题组原有工作基础上,作者收集和整理了全国数百个工程场地的钻孔资料,对所收集的钻孔资料进行了分类整理和分析研究,从中选出了近百个具有代表性的土层剖面作为分析计算的基本模型。根据研究的需要,本文还人工构造了若干个土层剖面作为计算模型。本文对模型选取和构造的原则、方法做了规定,并介绍了计算参数选取的原则。4.本文利用土层地震反应分析一维等效线性化的方法,计算了不同土层结构条件下,若干土层剖面的输出结果。在土层结构方面重点考虑了软弱夹层的厚度、位置和总覆盖层的厚度对地震动输出结果的影响,对计算结果进行了系统的分析,得到了一些有意义的结论。5.本文还对利用场地的传递函数来估计场地卓越周期,进行了初步的讨论。众所周知,工程场地是一个复杂的系统,地震波在这一复杂系统内的传播以及响应是一个极其复杂的科学问题。自上世纪初以来,人们对这一复杂问题的探索一直没有间断,并且得到了一重要价值的研究成果。相信,这一领域的研究还将收到岩土工程界的广泛关注。本文只是初步探索了土层结构对传递函数某些特征值的影响,由于水平所限,缺点和错误在所难免,敬请各位赐教。更多还原

【Abstract】 As an important content, people have been concerned about the influence of soil layer structure to ground motion, especially for site condition. The effects are studied from different direction in anti-seismic engineering because of the complexity of the soil layer. The amplification effect to ground motion due to different soil structure recurs to the concept of transform function under given input, and be described by amplification. The transform function is an important concept which to given input in frequency analysis and calculate the output of the system. Non-linear system input and output relationship is studied by using transform function in the geotechnical earthquake engineering field. In order to study the amplification of ground motion is studied through the effect of site condition and the given ground motion. The research is a very important part of the geotechnical earthquake engineering field and has important academic and practical meaning. The problem of ground motion due to soil structure is studied by using the equivalent linearization method to soil layer earthquake reaction and the transform function concept, the main content including:1. State-of-art for effect of ground motion caused by site condition are summarized in this paper, some research progress are introduced and discussed for ground motion caused by soil structure in detail.2. Concept and application for research of geotechnical earthquake engineering of transform function is introduced here. One-dimensional equivalent linearization method to soil layer earthquake reaction is also introduced and transform function is realized as well. Detailed analysis and reading to the concrete calculation procedure are carried on.3. About one hundred soil layer sections are selected to classify and study for calculating models from hundreds of drill materials based on the intrinsic working. The principle and method of selection and construction of calculation model and parameters are introduced and several manual soil layer section calculation models are constructed based on the need of research,4. Different soil layer structures which considering mainly the thickness、position and over layer thickness of soft intercalation are computed by using the one-dimensional equivalent linearization method to soil layer earthquake reaction. The computing results are analyzed systemic, some significative conclusions are got.5. This paper returns to estimate and discuss dominate period of site using transform function. Know to all, the engineering site is a complicated system. Transmit and response of the earthquake wave in the complicated system is a very complicated scientific problem. From last century, people study this problem at all times and obtain many important research results. The research will be come in for extensive attention. The effect of transform function for the soil layer structure is studied in this paper.更多还原