采用大三轴剪切仪对不同相对密度的双江口心墙坝覆盖层料,进行了K0固结及各向等压固结条件下的排水剪切试验,探讨了K0固结过程中粗粒土的变形特性。将K0固结与等压固结条件下的排水剪切试验的结果进行了对比分析。结果表明,K0固结加载阶段,平均主应力p与体应变εv之间、剪应力q剪应变εs之间的关系都可用幂函数形式表示。K0固结稳压阶段,εa-t关系呈指数关系。与等压固结试验相比,K0固结试样的排水剪强度略大。K0固结排水剪试验所得到的初始弹性模量Ei、初始泊松比vi均大于等压固结排水剪试验相同应力条件下的弹性模量、泊松比;且K0固结条件下试样的剪胀性也较为明显。
Using large-scale shearing device,K0 consolidated-drained triaxial test and isotropically consolidated-drained triaxial test under different confining pressures are performed for three relative density overburden material of Shuangjiangkou earth dam.The behaviour of coarse-grained soil under K0-consolidation is investigated.The test results from K0 consolidated-drained tests are compared with those from isotropically consolidated-drained tests.The results show that the relationship between mean principal stress and volumetric strain and between deviatoric stress and deviatoric strain during the K0-consolidation can be fitted with power function.In the stage with steady pressure after K0-consolidation,the strain-time curve can be fitted with exponential function.The strength of K0 consolidated-drained triaxial shear test is slight greater than that of isotropically consolidated-drained test.The initial elastic modulus Eiand Poisson’s ratio vi obtained from K0 consolidated-drained triaxial test is larger than that from isotropically consolidated-drained test.The dilatancy K0-consolidated sample is more evident.