饱和南京细砂液化后大变形特性试验研究  

STUDY OF BEHAVIOUR OF LARGE POST-LIQUEFACTION DEFORMATION IN SATURATED NANJING FINE SAND

作　　者：潘华[1] 陈国兴[1,2] 刘汉龙[2] 

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

出　　处：《岩石力学与工程学报》2011年第7期1475-1481,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金重大项目(90715018);国家公益性行业(地震)科研专项(200808022);江苏省研究生科研创新计划项目(CX10B_170Z)

摘　　要：利用空心圆柱扭剪仪对饱和南京细砂进行液化后静力再加载试验,研究其液化后应力–应变关系及孔隙水压力(孔压)消散特性,发现饱和南京细砂液化后的应力–应变关系呈S型曲线形状、归一化消散孔压与偏应力呈线性关系,据此提出饱和南京细砂液化后的本构模型和孔压消散模型,并进行该模型的验证性试验,结果表明2个模型的预测值与试验值较为吻合;探讨初始有效围压、相对密度对饱和南京细砂液化后特性的影响,分析结果表明:初始有效围压对饱和南京细砂液化后的本构模型及孔压消散模型均有较大影响;相对密度仅对液化后的本构模型有较大的影响,而对孔压消散模型基本没有影响。Laboratory tests on the large post-liquefaction deformation of saturated Nanjing fine sand were performed by using a hollow cylinder apparatus.The stress-strain relationship and the characteristics of excess pore water pressure after liquefaction were studied.It is found that the relationship between deviatoric stress and axial strain presented a sigmoid curve;and there is a good linearity relationship between normalized pore water pressure and deviatoric stress.On this basis,a constitutive model of stress-strain relationship and a dissipation model of excess pore water pressure are established.It is found that the results predicted by the two models are in good agreement with the experimental data.The influence of relative densities and confining pressure on the characteristics of liquefied soil are studied.The results show that the relative densities and initial effective confining pressure all have an important influence on the stress-strain relationship of liquefied saturated sand.However,the dissipation model of excess pore water pressure after liquefaction is only affected by the confining pressure.

关 键 词：土力学 饱和南京细砂 液化后大变形 本构模型 孔压消散模型 

分 类 号：TU435[建筑科学—岩土工程]