【作者】 赵冬冬；

【导师】 刘晶波；

【作者基本信息】 清华大学 ， 土木工程， 2013， 博士

【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。更多还原

【Abstract】 This dissertation looks at the seismic response characteristics of underground struc-tures through a systematic centrifuge shaking table model tests and numerical simulation.Centrifuge shaking table model tests were conducted for two-story underground structuresystems above different foundation types. The numerical models were calibrated and val-idated based on the results of model test. In addition, the influences of burial depth andsoil properties on the seismic response of underground structures were analyzed by thenumerical approach. Seismic response characteristics of large-space underground struc-tures were studied by the Pushover analysis such that the suitability and accuracy of thePushover analysis for underground structures were investigated. The main contributionsof this dissertation are described in as follows:(1) Orthogonal experimental design was carried out to study the material propertiesof the plaster mixture, including fracture strength, Young’s modulus and the ability ofwaterproof. As a result, a proper type of plaster mixture was obtained with lower strengthand better water resistance. Meanwhile, a type of low strength micro-particle concretewas made. In addition, the modeling accuracy on the prototype structure by using theproperties of plaster mixture and micro-particle concrete were verified by the numericalmodel. The utilization of these materials leads a more desirable failure mechanism of theunderground structures under the centrifuge shaking table tests.(2) A total of11dynamic centrifuge1/50scale model tests were performed to studythe seismic response of underground structure. The results of shaking table tests present-ed the seismic characteristics of the different foundations. Based on the measured data,acceleration responses and shear stress-strain hysteresis curve of those foundation typeswere obtained. In addition, the seismic responses of a two-story underground structurewith two spans under certain different foundations were achieved. The failure mecha-nisms of such underground structure are observed under the centrifuge shaking table testsuch that certain weak positions under seismic load were recognized.(3) A series of nonlinear analysis was carried out through the OpenSees platform.The nonlinear numerical model was established and validated in order to estimate theinteraction between free field foundation and seismic response of underground structures. The numerical coefficients, such as constitutive model of sand and clay model as well asthe damping ratio of the soil were calibrated by using the data from the centrifuge shakingtable tests. Improved numerical model was able to estimate the effect of burial depthand soil properties to seismic response of underground structures. The undesirable soilconditions were recognized in order to maintain a better seismic response of undergroundstructures.(4) A large-scale numerical model was established for measuring the nonlinear soil-structure interaction, which accounts for both static and dynamic modeling. A series ofelastic-plastic time history analyses were conducted on a large-space underground struc-ture in order to study seismic response characteristics and failure mechanism of suchstructural system. The efficiency of using PGRD and local PGRD as ground motionparameters in the seismic analysis of large-space underground structures was discussed.Meanwhile, pushover analysis was used to study seismic response of the large-space un-derground structure. With the comparison between different methods, the accuracy of thePushover analysis was investigated for such underground structures.更多还原