高地震烈度区深厚覆盖砂层液化研究  

Liquefaction of deep overburden layers in zones with high earthquake intensity

作　　者：蔡正银[1] 吴诗阳 武颖利[1] 张世殊 CAI Zheng-yin;WU Shi-yang;WU Ying-li;ZHANG Shi-shu(Geotechnical Engineering Department,Nanjing Hydraulic Research Institute,Nanjing 210024,China;Chengdu Engineering Corporation Limited,Chengdu 610027,China)

机构地区：[1]南京水利科学研究院岩土工程研究所,江苏南京210024 [2]成都勘察设计院有限公司,四川成都610027

出　　处：《岩土工程学报》2020年第3期405-412,共8页Chinese Journal of Geotechnical Engineering

摘　　要：砂土的振动液化受很多因素的影响,埋深(应力状态)就是一个非常重要的影响因素。为了研究深埋砂层地基的动力反应和液化规律,进行了离心机振动台试验。针对离心机振动台无法模拟深厚土层的问题,设计了模拟上覆土层荷载的加载气囊,通过控制气囊压力,可以模拟不同埋深砂层地基的地震反应情况,从而满足了深埋地基应力相似条件。试验共设置了4种工况,分别对应两种埋深和两种振动频率。研究揭示了不同埋深条件下砂土地基中的加速度反应规律和超静孔隙水压力反应规律,探讨了振动频率对深埋砂土地基振动特性的影响,为深埋砂土地基地震液化判别提供了较好的研究手段。The vibrating liquefaction of sandy soils is subjected to various factors,among which,the embedment depth(stress state)is a very important factor.The centrifugal shaking table tests are carried out to investigate the dynamic response and liquefaction rules of deep sand layers.For the problem that the deep soil layers cannot be simulated by the centrifugal shaking table,a loading air bag to simulate loads of overburden layers is designed.By controlling the pressure in the air bag,the seismic response situations of sandy layers with different embedment depths can be simulated.Accordingly,the stress similarity conditions of deep foundations are satisfied.Four kinds of test conditions are arranged,which respectively correspond two kinds of embedment depths and two kinds of vibrating frequencies.The response rules of acceleration and excess pore water pressure in the sand foundation with various embedment depths are released,and the influences of the vibrating frequency on the vibrating characteristics of deep sand foundations are discussed.It may provide a satisfactory way for judging the seismic liquefaction of deep sand foundations.

关 键 词：深厚覆盖层 离心振动台试验 砂土地基 加速度 超静孔压 

分 类 号：TU433[建筑科学—岩土工程]