地基砂土液化判别方法探讨  

Study on the method for evaluating sand liquefaction potential

作　　者：杨玉生[1] 刘小生[1] 刘启旺[1] 陈宁[1] 

机构地区：[1]中国水利水电科学研究院岩土工程研究所,北京100048

出　　处：《水利学报》2010年第9期1061-1068,共8页Journal of Hydraulic Engineering

基　　金：国家自然科学基金委员会和二滩公司雅砻江联合基金项目(50639060);水利部"948"项目(200929)

摘　　要：本文以我国《水利水电工程地质勘察规范》(GB 50287-2008)中的标准贯入锤击数液化判别法为基础,以该法进行应力修正的方法为依据,提出了采用附加应力等效埋深来考虑有限面积基础建筑物附加应力随深度扩散影响的液化判别新思路,以工程设计中参数取值常用平均值和小值平均值来考虑标贯击数和黏粒含量的离散性,同时借用有限元网格离散求解思路确定砂层可能液化的区域。以宁朗水电站闸坝工程为例进行了案例分析,结果表明:在地震设防烈度VII度时,闸基下中细砂层近震时不发生液化,远震时在闸基4个角点下的局部小区域内发生液化。In this paper, a new idea adopting equivalent fill embedded depth of subsidiary stress was put forward to consider the influence of subsidiary stress caused by superstructure with a finite foundation. It was based on the SPT blow count method in Code for Geological Investigation of Water Resources and Hydropower Engineering（GB 50287-2008）. Mean value method was used to consider the discreteness of the SPT blow count and clay content, and finite element method was used to determine the liquefaction area. A case study was introduced by evaluating the overburden liquefaction of the gate-dam structure in Ninglang Hydropower Station. The results showed that there was no liquefaction occurred in the sand layer under the gate-dam when suffering near earthquake, and only local areas at the corners of the structure were liquefied when suffering the far earthquake.

关 键 词：液化判别 标准贯入锤击数法 附加应力影响 离散性 

分 类 号：TU441[建筑科学—岩土工程]