场地地震动力变化表征参数研究

发布时间：2018-04-13 11:50

本文选题：震害 + 场地条件　；参考：《中国地震局兰州地震研究所》2017年硕士论文

【摘要】：场地的覆盖土层、地形地貌以及地下复杂的地质结构对地震动有十分重要的影响,它所引起的地震动差别可以造成不同场地上建筑物震害的差异。在进行大范围地震灾害预测和抗震设计时如何考虑复杂场地的差异性,如何估计此类场地在未来可能发生强震作用下的地震动参数分布等都是亟待解决的难题。本论文在前人工作的基础上,分别以平坦场地、起伏场地为研究对象,采用数值模拟的方法探究场地特征参数对地震场地动力变化的影响规律,提出表征地震动变化的场地特征参数,然后将所得结果应用于复杂区域场地的地震动预测中。本论文研究结果可为区域地震动预测提供理论依据,为制定区域长期发展规划和建筑抗震设计提供重要的基础资料,在防震减灾领域具有实际应用价值。论文获得的主要进展如下:1.构建56个水平场地模型,针对设防烈度VIII的区域选择了三种地震水平,采用一维等效线性化方法研究了三种地震作用下不同类别场地峰值加速度的变化规律,得到峰值加速度放大系数K分别与场地地面运动变化的表征参数Vse和Vs30的定量关系。2.运用ABAQUS软件建立起伏场地的有限元模型,探究不同地震动作用下起伏场地峰值加速度及频谱特性的变化特征,指出起伏场地受地形和土层共同作用,其放大效应约等于地形和土层各自单独放大效应的乘积。3.以设防烈度VIII的礼县地区为研究对象,通过地脉动观测与钻孔数据分析给出了场地卓越周期与等效剪切波速、覆盖层厚度的计算公式,并获得了研究区覆盖层厚度分布图、等效剪切波速Vse以及Vs30分布图。4.采用Vse和Vs30作为场地地震动力变化的表征参数,运用峰值加速度放大系数K分别与Vse和Vs30的定量关系预测礼县地区不同场地的地震动变化,并由一维等效线性化计算结果进行了验证。研究结果为区域范围内工程抗震和防灾减灾提供了合理的地震动参数。
[Abstract]:The ground motion is affected by the overlying soil, topographic landform and complicated geological structure. The difference of ground motion caused by the ground motion can cause the difference of earthquake damage of buildings on different sites.How to consider the difference of complex sites and how to estimate the distribution of seismic parameters of such sites under the action of strong earthquakes in the future is a difficult problem to be solved in earthquake disaster prediction and seismic design on a large scale.On the basis of previous work, this paper takes flat site and undulating site as research objects, and uses numerical simulation method to study the influence of site characteristic parameters on dynamic change of seismic site.The site characteristic parameters representing the variation of ground motion are presented, and the results obtained are applied to the prediction of ground motion in complex regions.The results of this paper can provide theoretical basis for regional ground motion prediction, provide important basic data for regional long-term development planning and seismic design of buildings, and have practical application value in the field of earthquake prevention and disaster reduction.The main progress of the thesis is as follows: 1.In this paper, 56 horizontal site models are constructed, three seismic levels are selected for the region of fortified intensity VIII, and the variation law of peak acceleration of different types of sites under three kinds of earthquakes is studied by using one-dimensional equivalent linearization method.The quantitative relationship between peak acceleration magnification factor K and ground motion parameters Vse and Vs30 is obtained.The finite element model of undulating site is established by using ABAQUS software, and the variation characteristics of peak acceleration and spectrum characteristic of undulating site under different ground motion are studied, and it is pointed out that the undulating site is affected by topography and soil layer together.The magnification effect is about equal to the product. 3 of the individual magnification effect of topography and soil layer.Taking Lixian area with fortification intensity VIII as the research object, through ground pulsation observation and borehole data analysis, the formulas of site excellent period, equivalent shear wave velocity and overburden thickness are given, and the distribution map of overburden thickness in the study area is obtained.Equivalent shear wave velocity Vse and Vs30 distribution. 4.Vse and Vs30 are used as the characterization parameters of site seismic dynamic change, and the quantitative relationship between peak acceleration magnification factor K and Vse and Vs30 is used to predict the ground motion change of different sites in Lixian area.The results of one-dimensional equivalent linearization are verified.The results provide reasonable ground motion parameters for earthquake resistance and disaster prevention and mitigation in regional engineering.
【学位授予单位】：中国地震局兰州地震研究所
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P315.9

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