城市地铁地下结构地震反应的试验研究与数值模拟

发布时间：2018-06-08 05:00

本文选题：地震反应分析 + 离心机振动台模型试验　；参考：《清华大学》2013年博士论文

【摘要】：本文通过离心机振动台模型试验和数值模拟的手段对地下结构地震反应特性进行了较为系统的研究。开展了不同类型地基-双层地下结构系统离心机振动台模型试验，通过对比试验结果标定数值模型，基于标定后的数值模型研究埋深和土层条件对地下结构地震反应的影响。采用数值模拟方法研究大空间地下结构地震反应特点，并对地下结构Pushover分析方法在大空间地下结构地震反应分析中的适用性和精度进行了分析。本文主要成果有：（1）为实现在离心机振动台试验中获得地下结构的破坏现象，采用正交试验方法对石膏复合材料的强度、弹性模量以及耐水性进行了系统的试验研究，得到了低强度和耐水性强的石膏复合材料。同时配置了低强度微粒混凝模型材料，并对石膏复合材料和微粒混凝土对原型混凝土结构的模拟精度进行了数值分析。（2）针对地下结构的地震反应问题，设计并完成了3组共11次1:50比尺的离心机振动台模型试验，研究了不同地基自由场地震反应和不同地基中地下结构的地震反应特性。试验取得了较为丰富、合理的数据，得到了不同地基自由场加速度反应规律和剪应力-剪应变变化关系，分析了不同地基中地下结构应变反应，并在试验中观察到地下结构破坏现象，发现了结构抗震不利部位。（3）基于OpenSees计算平台，建立了地基自由场和地基-地下结构动力相互作用系统非线性数值分析模型。通过与试验结果的对比，对数值模型及其中所采用的砂土、粘土本构模型参数与土体阻尼比计算参数进行了标定，采用标定后的数值模型研究了埋深和土层条件对地下结构地震反应的影响，讨论了对地下结构抗震性能产生不利影响的土层条件。（4）建立地基-地下结构非线性动力相互作用系统的静-动力联合分析有限元数值模型，对大空间地下结构进行弹塑性地震反应时程分析，研究了大空间地下结构地震反应规律和破坏特性，讨论了PGRD和局部PGRD作为地震动物理参数用于大空间地下结构地震反应分析时的合理性和有效性。同时采用地下结构Pushover分析方法对大空间地下结构进行了地震反应分析，讨论了地下结构Pushover分析方法在大空间地下结构地震反应计算中的适用性和精度。
[Abstract]:In this paper, the seismic response characteristics of underground structures are studied systematically by means of centrifuge shaking table model test and numerical simulation. The shaking table model test of centrifuge for different subgrade and double layer underground structure system was carried out. The numerical model was calibrated by comparing the experimental results. Based on the calibrated numerical model, the influence of buried depth and soil conditions on the seismic response of underground structure was studied. The characteristics of seismic response of large space underground structures are studied by numerical simulation, and the applicability and accuracy of pushover analysis method in seismic response analysis of large space underground structures are analyzed. The main achievements of this paper are as follows: (1) in order to achieve the failure phenomenon of underground structure in centrifuge shaking table test, the strength, elastic modulus and water resistance of gypsum composite are studied systematically by orthogonal test method. Gypsum composites with low strength and strong water resistance were obtained. At the same time, the model material of low strength particulate coagulation is configured, and the simulation accuracy of gypsum composite and particulate concrete to the prototype concrete structure is analyzed numerically. Three groups of shaking table model tests of centrifuge with 1:50 scale for 11 times have been designed and completed. The seismic responses of different ground free fields and underground structures in different foundations have been studied. The experimental results obtained abundant and reasonable data, obtained the law of acceleration response of different foundation free field and the relationship between shear stress and shear strain, and analyzed the strain response of underground structure in different foundation. The failure phenomenon of underground structure is observed and the unfavorable seismic position of the structure is found. Based on OpenSees calculation platform, the nonlinear numerical analysis model of the free field of foundation and the dynamic interaction system of foundation and underground structure is established. By comparing with the experimental results, the parameters of the numerical model and the sand, clay constitutive model and the damping ratio of the soil are calibrated. The effects of buried depth and soil conditions on the seismic response of underground structures are studied by using the calibrated numerical model. In this paper, the soil layer conditions which have adverse effects on the seismic behavior of underground structures are discussed. (4) the finite element numerical model of the nonlinear dynamic interaction system between ground and underground structures is established, and the finite element numerical model of static and dynamic joint analysis is established. The time history of elastic-plastic seismic response of large space underground structures is analyzed, and the seismic response and failure characteristics of large space underground structures are studied. The rationality and validity of PGRD and local PGRD as physical parameters of ground motion for seismic response analysis of large space underground structures are discussed. At the same time, the seismic response of large space underground structure is analyzed by pushover analysis method, and the applicability and accuracy of pushover analysis method in seismic response calculation of large space underground structure are discussed.
【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU311.3;TU93

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