【作者】 鲍鹏；

【导师】 姜忻良；

【作者基本信息】 天津大学 ， 结构工程， 2005， 博士

【摘要】 随着地下空间开发和地下结构建设规模的不断加大,地下结构的抗震设计及其安全性评价的重要性、迫切性愈来愈明显。本文结合天津地铁1号线工程,针对地铁区间隧道结构和地铁车站结构的抗震问题,提出了基于可变形体模型的离散元法和相应的人工粘滞边界以及与无限元耦合的方法。对地铁区间隧道结构在人工地震波作用下的动力反应进行了分析计算,为地铁区间隧道结构设计及抗震设防提供依据;对天津地铁1号线土城车站结构进行了动力分析计算。得出了地铁车站框架结构在不同地震波作用下的地震反应。本文利用可变形体模型的离散元方法,分析了刚性桩复合地基桩土共同作用的承载机理。本文的主要工作如下:1.基于变形体动力学原理,建立了新的可变形块体单元模型。根据离散元法原理,采用边-边接触关系及动态松弛法,推导出其理论公式并编制了计算程序。通过选取适当的计算参数对典型算例进行分析计算,得到了静力平面问题的应力、位移分布及静态解的收敛过程,验证了计算程序和计算参数选取的正确性。证明了该方法用于岩土工程静力计算的可行性。2.利用可变形体单元模型的离散元法,针对地铁区间隧道结构的震害特点,求出了地下结构在人工地震波作用下的动力反应,为地铁区间隧道结构设计及抗震设防提供依据。3.推导出无限元相应的理论公式并实现在边界上与离散元的耦合。采用近场土体由离散元模拟,远场土体由无限元模拟,进行土-地下结构相互作用分析。由静力问题的收敛性,验证了计算程序和计算参数选取的正确性,给出了地下结构在地震波作用下的位移反应。4.依据可变形体模型的离散元方法,对刚性桩复合地基的竖向承载能力以及桩土共同作用过程中桩、土承担荷载比例的变化规律进行了计算分析,揭示了刚性桩复合地基桩土共同作用的承载机理。5.针对天津地铁1号线土城车站实际工程,使用可变形离散元法对地下结构-土动力相互作用系统进行了分析计算。得出了地铁车站框架结构在天津波、人工波(中震)及人工波(小震)作用下的地震反应(动内力、动位移)。分析了地震反应可能对地铁车站造成的破坏,对地铁车站的结构设计提出了指导性意见。更多还原

【Abstract】 Along with the space development and the increased construction scale of underground structure, the importance and urgency of the seismic design and the safety evaluation for the underground structure is becoming more and more obvious. In this paper, combined with the project of Tianjin Subway No.1 Line, discrete element method (DEM) which bases on deformable bodies, the corresponding artificial viscous boundary, and the coupling method for infinite element and DEM are applied to the seismic problem of the metro tunnel and station. The dynamic response of the metro tunnel in artificial waves is analyzed and calculated, which may provide a basis for the tunnel design and the seismic fortification. The Tucheng Station in Tianjin Subway No.1 Line is discussed in DEM, and the earthquake response of the station frame structure in different earthquake waves is gotten. Also DEM is applied to analyze the bearing mechanics for rigid piled compound foundation. The main work is as follows:1. Based on the principle of deformation dynamics, a new element model for deformable bodies is established. From the side-side contact relation and the dynamic relaxation method, theoretical formulas are derived and the corresponding calculation program is worked out according to the DEM. From the analysis on a typical example, we get not only the distribution of the stress and the displacements, but also the convergence of the static solution, verify the validity of the calculation program and the selected parameters. The feasibility of this method used in the static analysis of geotechnical engineering is proved.2. Considered the features of earthquake disaster, the dynamic response of underground structure in artificial wave is gotten with DEM, which may provide a basis for the metro tunnel design and the seismic fortification.3. The corresponding theoretical formula of infinite element was deduced and in the boundary, the discrete element- infinite element coupling ware achieved. The analysis of the soil-underground structure interaction effects was carried out when the nearby soil was described as discrete elements and the soil beyond as infinite ones. The valid of the calculating program and the selection calculating parameters were tested. The dynamic reaction of underground structure was obtained under the earthquake waves.4. In this paper, the bearing capacity of rigid pile composite foundation under vertical loads and the law of variation of pile-soil bearing ratio among pile-soil interaction are calculated and analyzed on the basis of DEM of the deformable body model, which describes the bearing mechanism of pile-soil interaction of rigid pile composite foundation.5. In this paper, based on DEM, dynamic soil-underground structure interaction system is analyzed and calculated to practical project of Tucheng station of Tianjinsubway No.1 line. Seismic responses (including dynamic internal force and dynamic displacement) of Tianjin subway station frame, under action of Tianjin wave、artificial wave (middle earthquake) and man-made wave (small earthquake), are come out. Possible damage to subway station brought about seismic response is analyzed; some instructing suggestions about structure design of subway station are also indicated in this paper.更多还原