饱和南京细砂永久应变势模型的试验研究  

Experimental study on a model of the permanent strain potential for saturated Nanjing fine sand

作　　者：王炳辉[1] 陈国兴[1] 刘汉龙[2] 胡庆兴[1] 

机构地区：[1]南京工业大学岩土工程研究所,江苏南京210009 [2]河海大学岩土工程科学研究所,江苏南京210098

出　　处：《世界地震工程》2011年第2期1-8,共8页World Earthquake Engineering

基　　金：国家自然科学基金重大研究计划项目(90715018);国家重点基础研究发展计划项目(2007CB714200);国家公益性行业(地震)科研专项项目(200808022);江苏省高校自然科学重大基础研究项目(08KJA560001)

摘　　要：土单元永久应变势的预测模型是土动力学的重要研究内容之一。现有的土单元永久应变势模型没有反映振动孔压增长的影响,难以合理解释地震动作用引起的饱和砂土地基永久变形一般是由土层软化或再固结变形所致的机理。基于饱和南京细砂永久变形动三轴试验结果的有效应力状态分析,研究了试样的永久变形与振动孔压增长的关系,建立了一个能反映振动孔压增长影响的土单元永久应变势模型,给出了土单元永久应变势的数学表达式,分析了土单元永久应变势模型参数的影响因素。初步的验证性试验表明:模型预测与试验测得的试样永久应变势与振动孔压增长曲线比较接近,说明该模型具有一定的合理性。The research on the model of the permanent strain potential of soil element is an important task of soil dynamics.The previous models on this issue have not considered the influence of the pore water pressure growth in sand soils on the permanent strain potential of soil element,which are difficult to explain the mechanism of the earthquake-induced settlement of foundation mainly caused by soften or re-consolidation deformation of saturated sand soil foundation reasonably.Based on the effective stress state analysis of the results of dynamic triaxial tests on saturated Nanjing fine sand,the relationship between the pore water pressure growth and the permanent strain potential of the sample is studied.A model of the permanent strain potential is established,which can reflect the effect of pore water pressure growth,further more,a formula of the model is proposed,and the effects of the parameters of the model are also analyzed.The results of preliminary verification show that the curves of pore water pressure and permanent strain potential growth with the predicted model are approaching to that of test results.So this indicates that the model of the permanent strain potential is rational.

关 键 词：饱和南京细砂 永久应变势 振动孔压 有效应力状态 

分 类 号：TU435[建筑科学—岩土工程] U442.55[建筑科学—土工工程]