场地地震反应的等效线性化分析应用研究

发布时间：2018-03-17 12:23

本文选题：土体动力本构模型　切入点：傅里叶变换　出处：《安徽建筑大学》2015年硕士论文　论文类型：学位论文

【摘要】：为防御地震造成的灾害而采取的重要工程措施之一是场地的地震反应分析,并且地震反应分析的数据结果为抗震设防及提高工程结构的抗震水平提供重要的参考依据。按照土体的动力特性,对场地地震反应分析方式可分为线性化方法和并行有限元非线性方法。其中等效线性化方法容易被应用,操作和原理简单,适合小震分析或是横向均匀的情况,同时其最后分析时采用“放大低频,缩小高频”的方法,而在处理强震作用和复杂场地下的反应分析时其准确性会受到影响,因此采用线性方法存在局限性,非线性方法处理非均匀场地更加合理,但在实际操作处理结果时参数较多,参数选取受很多因素影响,一般在专业性的科学研究中被采用,在实际工程方案中应用并不是很广泛,在接下来研究工作中需要对其方法进行改进与完善。本文根据实测的钻孔地震波波速测试以及地震安全性评价工作中的场地钻孔参数资料,在一维场地等效线性化原理基础上,采用场地地震反应分析程序对两个具体场地进行了相应勘测资料的数值计算和分析研究。本文主要工作和研究内容如下:1、对本课题的研究背景以及现实意义进行了概述,对国内外在该领域的有关发展及主要的研究方法、研究现状进行了总结说明。2、对几种土体动力本构关系常见的模型进行了介绍与对比分析,并且对滞回曲线在不同应力下的规律进行了研究分析。3、重点分析在众多水平成层场地反应分析中较成熟的两种方法的原理及适用范围,即采用解析方法分析一维场地模型地震反应和采用半解析方法分析不同参数下非线性变化的土层的动力特征及地震反应分析。4、详细分析水平成层场地地震反应中采用集中质量法思想进行分析的时域分析方法,在具体程序MATLAB编程用到了可以减少计算量的傅里叶变换,并且阐述了地震分析反应中应用比较多的三种程序(DENSOR98、SHAKE91、LSSRLI-1),重点分析了前两种程序的原理及使用方案。在此基础上作者对编程进行了研究,得到了分析场地的编程语言。5、根据两个具体工程钻孔实际观测资料及动力参数,在理想的土层一维波动模型基础上使用等效线性化方法对场地地震反应进行计算,由基岩处的加速度得到场地地表处峰值加速度反应谱分析结果,并对其平均反应谱曲线进行计算,给出该工程场地地表水平向5%阻尼比的规准化反应谱曲线。以此做为规范中所要求的设计反应谱形式进行技术衔接的科学依据。6、简要总结适用于复杂地层的二维、三维场地反应分析模型,对以后尚且需要解决的问题及开展工作的提出建议。
[Abstract]:One of the important engineering measures taken to prevent disasters caused by earthquakes is the seismic response analysis of the site. The results of seismic response analysis provide an important reference for seismic fortification and improvement of seismic level of engineering structures, according to the dynamic characteristics of soil, The seismic response analysis of the site can be divided into linearization method and parallel finite element nonlinear method, in which the equivalent linearization method is easy to be applied, simple in operation and principle, and suitable for the case of small earthquake analysis or lateral uniformity. At the same time, the method of "enlarge the low frequency, reduce the high frequency" is adopted in the final analysis, but the accuracy of the analysis of the underground response of the strong earthquake action and the complex field will be affected, so the linear method has some limitations. The nonlinear method is more reasonable to deal with the non-uniform site, but it has many parameters in practical operation, and the selection of parameters is affected by many factors, so it is generally used in professional scientific research. It is not widely used in practical engineering projects. In the following research work, it is necessary to improve and perfect the method. Based on the measured data of borehole seismic wave velocity and site borehole parameters in seismic safety evaluation, based on the one-dimensional site equivalent linearization principle, The numerical calculation and analysis of the corresponding survey data of two specific sites are carried out by using the site seismic response analysis program. The main work and contents of this paper are as follows: 1. The research background and practical significance of this subject are summarized. The development and main research methods in this field at home and abroad are summarized. 2. Several common models of soil dynamic constitutive relations are introduced and compared. And the law of hysteretic curve under different stress is studied. 3. The principle and application range of two methods which are more mature in the field response analysis of many horizontal layers are emphatically analyzed. That is, using analytical method to analyze the seismic response of one-dimensional site model and semi-analytical method to analyze the dynamic characteristics and seismic response of soil layer with nonlinear variation under different parameters .4.The seismic response of horizontal stratified site is analyzed in detail. The time domain analysis method based on lumped mass method, In the specific program MATLAB programming used to reduce the amount of calculation of Fourier transform, Three programs, DENSOR98 / SHAKE91 / LSSRLI-1, which are widely used in seismic analysis and response are described. The principle and application scheme of the former two programs are emphatically analyzed. On the basis of this, the author studies the programming. The programming language .5for analyzing the site is obtained. According to the actual observation data and dynamic parameters of the drilling holes in two concrete projects, the equivalent linearization method is used to calculate the seismic response of the site on the basis of the ideal one-dimensional wave model of soil layer. The peak acceleration response spectrum of the ground surface is obtained from the acceleration at the bedrock, and the average response spectrum curve is calculated. The normalized response spectrum curve of the horizontal damping ratio of 5% on the ground surface of the project site is given, which is used as the scientific basis for the technical connection of the design response spectrum form required in the specification, and a brief summary of the two-dimensional response spectrum suitable for complex strata is given. Three-dimensional site response analysis model, to the future need to solve the problems and put forward suggestions for the work.
【学位授予单位】：安徽建筑大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU435

【参考文献】