重大工程抗震分析的地震输入模型与方法研究

Many major civil infrastructures in China face the earthquake risk. Dynamic soil/rock-structure interaction should be considered in seismic analysis, due to the important effect of the rock and soil properties to the seismic response and damage of structure. The so-called time-domain direct method is usually used, in which a numerical structure-rock/soil interaction model is constructed. This project studies the earthquake input model and method for the structure-rock/soil interaction model. The three typical rock and soil site models outside the structure-rock/soil interaction model are considered, i.e., the horizontally layered half space site, the saturated porous medium site, and the site including fault. The method for inputting the obliquely incident earthquake motion or the fault movement is proposed. It includes the artificial boundary condition for modeling the radiation damping of the truncated rock and soil media, the analysis method for the seismic response of the free field site, and the input method of the seismic site response on the artificial truncation boundary. When the structure exists, the earthquake input is considered for two kinds of special cases, i.e., the structure truncation boundary for long structure, and the rock and soil truncation boundaries on the top of the interaction model of deep structure. The effect of the earthquake input for the different sites on the seismic responses of some typical underground structures is studied. The situation that the research on earthquake input lags behind that of the structure-rock/soil model will be improved by the systematic studies in this project. The effective earthquake input model and method will be provided for the seismic analysis of the major civil infrastructures.

我国重大基础设施工程面临地震威胁。工程结构地震反应及损伤破坏过程受周围岩土介质影响，结构抗震分析需要考虑结构与岩土介质的动力相互作用，采用时域整体分析方法，即建立结构及其附近岩土介质的整体分析模型。本项目研究整体分析的地震输入模型与方法。针对整体分析模型外部的三类典型场地模型，即水平成层半空间、含饱和孔隙介质以及含近地表断层场地，建立倾斜入射地震动或断层错动的输入方法，包括模拟被截去岩土介质辐射阻尼的人工边界条件、场地地震反应计算方法、以及场地地震反应的人工边界输入方法。建立两类特殊地下结构形式的地震输入方法，即长大结构的结构截断边界、以及深埋结构岩土介质顶部截断边界的地震输入方法。研究不同场地模型条件下倾斜入射地震动或断层错动对典型重大地下工程结构地震反应的影响。本项目将弥补重大工程抗震整体分析中粗糙地震输入与精确整体分析模型不匹配的不足，为重大工程抗震分析提供有效的地震输入模型与方法。

我国重大基础设施工程面临地震威胁。工程结构抗震分析需要考虑结构与周围岩土介质的动力相互作用，当采用时域整体分析方法时，需建立结构及其附近岩土介质的整体分析模型。本项目研究整体分析的地震输入模型与方法。针对水平成层半空间、含饱和孔隙介质和含近地表断层场地模型，建立了重大工程整体分析模型人工边界理论，包括高精度人工边界条件、黏弹性人工边界条件以及给出了人工边界设置位置建议；建立了倾斜入射地震动和断层错动作用下场地静动力反应的计算方法，给出了场地反应的人工边界输入方法；建立了长大和深埋地下结构的地震输入方法，并总结了地震动和断层错动作用对典型重大地下工程结构反应的影响规律。本项目在一定程度上能够改变重大工程抗震整体分析中粗糙地震输入与精确整体分析模型不匹配的现状，为重大工程抗震分析提供有效的地震输入模型与方法。本项目发表学术论文34篇，其中SCI论文27篇、EI论文4篇；参编专著《城市轨道交通结构抗震设计》，该专著为《城市轨道交通结构抗震设计规范GB50909-2014》的宣贯教材；申请专利5项，其中授权3项；软件著作权3项；参与获得2017年国家科技进步二等奖1项，获2017年《力学学报》影响力提升优秀贡献奖。