饱和地基中地下结构地震反应若干问题研究  

Research on Seismic Response of Underground Structures in Saturated Foundation

作　　者：李鹏[1] 刘光磊 宋二祥[1] 

机构地区：[1]清华大学土木工程系,北京100084 [2]北京中岩大地工程技术有限公司,北京100041

出　　处：《地震工程学报》2014年第4期843-849,共7页China Earthquake Engineering Journal

基　　金：清华大学自主科研计划项目(20121087977);国家自然科学基金重点项目(51038007);博士后科学基金项目(2014M560978)

摘　　要：简要综述笔者所在课题组近十年在饱和地基中地下结构抗震研究方面的主要成果,包括:(1)饱和两相介质中波动方程及波动特性的探究;(2)动力有限元计算的传输边界研发;(3)饱和地基中地下结构地震反应离心机模型试验研究;(4)饱和地基中地下结构地震响应的有限元分析;(5)饱和砂土地基中地下结构上浮机理研究等。这些成果以较为深入地研究饱和两相介质波动理论为基础,通过模型试验、数值仿真、机理探究等方法认知饱和地基中地下结构地震反应机理,对于完善饱和地基中地下结构抗震设计方法及提高抗震安全措施等均具有参考价值。The main achievements of 10 years of research on the seismic response of underground structures in a saturated foundation are presented in this paper.Systematic clarification and investigation are conducted on the dynamic basic formulations and wave propagation characteristics of saturated soils.In the dynamic analysis of saturated soils,the interaction between the soil skeleton and pore water consists of two parts：seepage force and inertial coupling force.It is also revealed that due to the existence of the inertial coupling force,the speeds of two dilatational waves are not equal to those in single-phased solid skeleton and pore water even if the permeability approaches infinity.Moreover,several transmitting boundaries for dynamic analysis of saturated porous media are developed,including the viscous-spring transmitting boundaries derived from both the u-p formulation and u-Uformulation in addition to the high-order time-domain transmitting boundary derived from the cylindrical elastic wave radiation problem based on the u-pformulation.Despite the zero permeability assumption made in the derivation of the undrained boundary,results show that it can provide sufficiently accurate results for earthquake engineering problems.The drained boundary performs well for all permeabilities.In addition,four dynamic centrifuge tests at 1：50scale are performed to study the earthquake response of a subway tunnel in liquefiable soils.The response characteristics of the subway tunnel in horizontal or oblique liquefiable soils including floatation,lateral displacement of the tunnel,and internal force increments in tunnel segments due to earthquake-induced liquefaction are investigated in addition to the effectiveness of cut-off walls in resisting tunnel flotation.Further,finite element simulation is conducted to analyze the earthquake response of underground structures in saturated soils.We adopt the finite element program DIANA SWANDYNE II,which is a two dimensional（2D）,effective stress-based program compiled from the fu

关 键 词：饱和地基 抗震分析 传输边界 地下结构 离心机振动台试验 

分 类 号：TU435[建筑科学—岩土工程]