饱和砂土地层中隧道结构动力离心模型试验  

Dynamic centrifuge tests on seismic response of tunnel in saturated sandy foundation

作　　者：刘光磊[1] 宋二祥[1] 刘华北[1] 龚成林[1] 

机构地区：[1]清华大学土木工程系地下工程研究所,北京100084

出　　处：《岩土力学》2008年第8期2070-2076,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.50378050);北京市自然科学基金重点项目(No.8061003)

摘　　要：饱和砂土地层中隧道结构可能会因地震地基液化而发生破坏。通过对可液化地层中地铁隧道结构的地震反应进行动力离心模型试验,研究了饱和松砂地基在地震作用下的反应特性、可液化地层中地铁隧道结构的上浮及变形特性和设置截断墙对限制隧道结构上浮的效果等问题。研究结果表明,地基液化引起的隧道衬砌上的附加变形内力以及隧道上浮量主要受地基液化时土水压力的变化影响。截断墙的设置限制了隧道两侧土体向隧道下方流动的趋势,有效减小了隧道结构的上浮量。Tunnels in saturated sandy foundation may subject to severe damage due to earthquake-induced liquefaction.Dynamic centrifuge tests on seismic response of metro tunnel in liquefiable soil are conducted.The seismic response of saturated loose sandy deposit,the uplift and deformation performance of metro tunnel in liquefiable soil are investigated.The effectiveness of cut-off walls in reducing structure uplift is also validated.Test results show that the liquefaction induced inner force in tunnel segments and its uplift are mainly influenced by excess pore pressure and earth pressure increment during earthquake.The cut-off walls prevent liquefied soil from moving toward the bottom of the tunnel,and then the uplift of the tunnel is reduced effectively.

关 键 词：离心机试验 砂土液化 地下结构 截断墙 

分 类 号：TU435[建筑科学—岩土工程]