考虑地震动特性的饱和砂土震陷计算方法  

Calculation method of saturated sand compression considering seismic motion characteristics

作　　者：高广运[1,2] 谢伟 王禹 GAO Guangyun;XIE Wei;WANG Yu(Department of Geotechnieal Engineering, Tongji University, Shanghai 200092, China;Key Laboratory of Geotechnieal and Underground Engineering of Ministry of Edueation, Tongji University, Shanghai 200092, China;Department of Civil and Environmental Engineering, The University of Auekland, Auekland 1010, New Zealand)

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092 [3]新西兰奥克兰大学土木与环境工程系

出　　处：《地震工程与工程振动》2018年第2期10-17,共8页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金项目(41372271)~~

摘　　要：为探究地震动特性对砂土震陷的影响,提出合理的震陷评价方法,本文利用开源有限元平台Open Sees对饱和砂土自由场地震陷进行数值模拟,研究了地震动维度和方向角对砂土震陷的影响,以震陷比为评价指标,分析了水平单向荷载简化二维荷载的合理性,并对震陷和震陷比与地震动强度参数进行相关性研究,提出了考虑地震动特性的饱和砂土震陷计算方法。结果表明:饱和砂土在地震动水平双向荷载作用下的孔压和震陷均大于单向加载结果,但小于两个单向荷载分别施加产生的结果之和,也小于任一单向加载下结果的2倍;地震动方向对震陷比影响显著,且不同地震动得到的最大震陷比对应的方向角存在差异,表明采用某一确定方向的一维荷载简化分析二维荷载的方法并不合理;震陷量与地震动强度参数Sa(0.6 s)和VSI相关性较好,以VSI为参数提出的预估公式可快速计算震陷量;砂土相对密度越大,计算结果越准确。In order to explore the influence of seismic motion characteristics on sand compression and propose a reasonable evaluation method of sand seismic compression,this paper used the open source finite element platform Open Sees to simulate the seismic compression of sand,and the influence of seismic dimension and directionality on the compression of saturated sand is studied. Using the seismic collapse ratio as the evaluation index,the rationality of the simple one-way load to simplify the two-dimensional load is analyzed,and the correlation between seismic compression and seismic load parameters is studied. Finally,a method for calculating the saturated sand compression which considers the characteristics of seismic motion is proposed. The results show that the pore water pressure and the seismic compression of the saturated sand under horizontal bidirectional seismic load are larger than horizontal unidirectional loading results,but less than the sum of the result of the two unidirectional load and twice the result of any unidirectional loading. The direction of the seismic motion has a significant effect on the seismic subsidence ratio,and the maximum sag ratio obtained by different seismic motion is dissimilar from the corresponding angle. It is not reasonable to use a one-dimensional load of a certain direction to simplify the analysis of two-dimen-sional loads. The correlation between the seismic load and it＇s strength parameter Sa（0. 6 s） and VSI is good,and the prediction formula which uses VSI as a parameter can quickly calculate the amount of seismic; the greater the relative density of sand,the more accurate the calculation results.

关 键 词：砂土震陷 地震动特性 震陷比 相对密度 OPENSEES 

分 类 号：TU43[建筑科学—岩土工程]