液化对砂土场地地表加速度响应的影响  

Influence of Liquefaction on the Responses of Acceleration on the Ground Surface of Sand Layer

作　　者：苏栋[1] 高翔[2] 明海燕[1] 包小华[1] 

机构地区：[1]深圳大学土木工程学院,广东深圳518060 [2]建设综合勘察研究设计院有限公司,广东深圳518054

出　　处：《防灾减灾工程学报》2016年第1期69-74,共6页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金项目(51478273);深圳市基础研究项目(JCYJ20140418095735556)资助

摘　　要：在饱和砂土场地振动过程中,孔隙水的发展会影响土体的有效应力和土骨架对地震波的传播。采用离心机动力试验和数值分析手段对不同强度振动作用下的砂土场地响应进行了研究,并利用观测和计算结果对现行液化评估简化方法进行了分析验证。结果表明:当振动强度较大时,土体的液化将导致加速度急剧衰减;采用完全耦合分析能再现超静孔压的发展和液化对加速度传播的影响,但总应力分析严重高估了地表的加速度;应用简化方法进行液化评估时,确定地表处水平加速度峰值应考虑场地对地震波的放大效应,但应忽略超静孔压的影响。Development of pore pressure will exert an effect on the effective stress of soil and transmission of seismic waves through soil skeleton.This paper presents the study of sand ground responses under shaking of different intensities by use of centrifugal dynamic tests and numerical analyses.The centrifugal test and numerical analysis results are used to verify the simplified procedure for evaluating the liquefaction potential of soil.It is found that soil liquefaction results in attenuation of acceleration when the shaking is strong.Fully coupled analysis can reproduce the development of excess pore pressure and attenuation of acceleration,but the total stress analysis overestimates the acceleration on the ground surface.It is shown that the evaluation of the peak acceleration on the ground surface should incorporate the influence of site amplification,but neglect the influence of excess pore-water pressure when using the simplified procedure for evaluating the liquefaction potential of soil.

关 键 词：砂土 液化 加速度 完全耦合分析 

分 类 号：TU375[建筑科学—结构工程]