【作者】 李大为；

【导师】 景立平；

【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】 多次地震的震害调查和强震观测结果表明,场地条件对地面运动有重要的影响。其中,土层地震反应是研究地面运动的关键问题之一。目前土层地震反应分析常用的方法是基于等效线性化方法的一维土层地震反应计算方法。考虑到等效线性化方法本身有一定的缺陷和不完善的地方,尤其是不能考虑孔隙水压力的影响,本文所做研究也是围绕一维土层地震反应分析这一问题展开,具体工作如下:1.对一维土层反应分析方法的研究现状进行了简要的总结,主要介绍了目前常用的几种应力应变模型及其特点,讨论了孔隙水压力在地震反应分析中的作用,并介绍了几类常用的分析孔隙水压力的方法。2.介绍了目前国内地震工程界中常用的一维等效线性化土层地震反应分析程序的基本原理及计算流程,并简要的分析了这一方法的优缺点。3.提出了基于有效应力原理的土层非线性反应分析方法,推导了时域非线性显式有限元计算公式,介绍了本文采用的本构模型、孔隙水压力计算模型及剪切模量修正方法。对于边界条件的处理,主要介绍了多次透射边界和粘性边界条件,并进行了简单的对比分析。4.应用本文方法编制了计算分析程序,数值计算了含孔隙水及不含孔隙水的一维土层非线性地震反应,并与同样土层条件下的等效线性化方法计算结果进行了对比分析。数值实验表明,本文方法在计算中不仅能体现土的非线性性质,而且能考虑到孔隙水在土层动力反应分析中的影响,能更好的模拟土层的实际情况。最后,对全文工作进行了总结,并讨论了进一步工作的发展方向。更多还原

【Abstract】 Large amount of earthquake damage surveys and strong eismic observation results show that site condition has important influence on ground motion. Thereinto, seismic response of soil layer is the key problem in the study of ground motion. At present, the common method of seismic response analysis of soil layer is one-dimensional seismic response method of soil layer based on equivalent linearization method. With the deficiency and imperfection of equivalent linearization method, especially it can’t consider the infection of the pore water pressure .this paper also develops research on one-dimensional seismic response analysis of soil layer, specifically shown as follows:1. The research status on one-dimensional seismic response method of soil layer is simply summarized; especially several stress-strain models and characteristic in common use are introduced. The function of pore water pressure in the analysis of seismic response is discussed, and several common methods of pore water pressure are introduced.2. The basic principle and compute flow of one-dimensional seismic response analysis program of equivalent linearization which is used worldwide at present are introduced; the advantages and disadvantages of this method are also simply analyzed.3. This paper puts forward the nonlinear response analysis method of soil layer based on principle of effective stress, with introducing the constitutive model、pore pressure model and modified method of shear modulus. As for the disposal of boundary condition, the multi-transmission boundary condition and viscosity boundary condition are introduced and simply analyzed.4.Based on the method presented in this paper, the nonlinear computational analysis program is compiled, and calculate one-dimensional seismic response of soil layer about with pore water and without pore water . And the results obtained by numerical computation are compared with the results obtained by equivalent linearization method in the same condition of soil layer. Numerical experiments demonstrate that this method can not only express the nonlinear characteristic of soil but also consider the influence of pore water in dynamic response analysis of soil layer, so as to simulate the actual condition of soil layer better. At last, all the works done in this paper are summarized, and further research direction in this area is discussed.更多还原