随机地震荷载作用下黄土震陷的影响因素研究  

STUDY OF INFLUENCING FACTORS OF LOESS SEISMIC SUBSIDENCE INDUCED BY STOCHASTIC SEISMIC LOAD

作　　者：邓龙胜[1] 范文[1,2] 

机构地区：[1]长安大学地质工程与测绘学院,陕西西安710054 [2]长安大学国土资源部岩土工程开放研究实验室,陕西西安710054

出　　处：《岩石力学与工程学报》2011年第9期1924-1931,共8页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(40972181);教育部科学技术研究重点项目(109146);地质灾害防治与地质环境保护国家重点实验室开放基金(GZ2009-20)

摘　　要：首先采用场地未来50 a超越概率10%的地震波作为输入激振波进行动力试验,根据试验结果对随机荷载作用下黄土震陷的残余动应变表达式进行修正,通过多组试验数据的反复验证,修正后模型与试验结果相关性较好。其次,通过控制人工合成地震动时程的功率谱和包络函数相关参数,得到不同卓越频率和有效持时的地震动时程,并据此进行动三轴试验,研究卓越频率和有效持时对黄土残余应变的影响效应,结果表明:卓越频率高、有效持时长的地震荷载作用下,相同动应力引起土体的残余变形较大。另外,固结比和含水量对黄土的残余应变也有较大的影响,在同一动应力作用下,高固结比和高含水量时试样将产生更大的残余应变。Certain earthquake wave with 10% exceeding probability in the following 50 years of the field is input as vibration wave to conduct the dynamic test firstly.The residual dynamic strain calculation expression is amended based on the test results.According to repeating verifications of a great many groups of test data,it is shown that there is good correlation between the amended expression and test results.Secondly,Through controlling the correlative parameters of power spectrum and envelope function of artificially synthesized seismic histories,earthquake waves with different predominant frequencies and effective times are obtained to control the axial stress of dynamic triaxial test.The effects of predominant frequency and effective time on the residual strain of loess are studied.The study results show that the sample suffering the earthquake acceleration wave with higher predominant frequency and longer effective time indicate larger residual strain under the same dynamic stress.In addition,moisture content and consolidation ratio have greater effect on the residual strain of loess.Under the same dynamic stress,the sample with higher moisture content and suffering higher consolidation ratio would produce more seismic residual strain.

关 键 词：土力学 随机地震荷载 黄土震陷 残余应变 卓越频率 有效持时 

分 类 号：TU43[建筑科学—岩土工程]