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.
出处
《防灾减灾工程学报》
CSCD
北大核心
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
关键词
砂土
液化
加速度
完全耦合分析
sand
liquefaction
acceleration
fully-coupled analysis