K0固结粗粒土剪胀特性大型三轴试验研究

采用大型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 固结及各向等压固结条件下的排水剪切试验，探讨了 固结及各向等压固结条件下粗粒土剪胀性的差异，并检验了修正Rowe剪胀方程对 固结粗粒土的适用性。结果表明：粗粒土在 固结条件下，较各向等压固结条件下的剪胀性明显，且这种差异性在密度较小的粗粒料中体现较为突出，而随着密度的增加，差异性逐渐减弱；对试验数据进行非线性拟合,总结出剪胀因子 与相对密度 、围压 之间的关系式，据此可分析不同紧密程度粗粒料剪胀性的强弱；对 固结粗粒土，修正Rowe剪胀方程能较好地描述其剪胀性。

Study of shear dilatancy behaviors of coarse-grained soil in large-scale triaxial tests under K0-consolidation condition

Using large-scale shearing device, consolidation-drained triaxial test and isotropic consolidation-drained triaxial test under different confining pressures are performed for three relative densities (0.9, 0.8, 0.7) overburden material of ShuangJiangKou earth dam. The difference between dilatancy behaviours of coarse-grained soil under -consolidation and isotropic consolidation is investigated. Meanwhile, applicability of the modified Rowe dilatancy equation for coarse-grained soils under -consolidation is tested. The test results show that the dilatancy under -consolidation is more remarkable than that under isotropic consolidation; and this difference is more obvious for coarse-grained soils with lower density. By means of the nonlinear fitting of the results of triaxial tests, a relationship formula for coarse-grained soils under -consolidation and isotropic consolidation among dilatancy factor and relative density and confining pressure is obtained, according to which, the dilatancy’ strength of coarse-grained soil under different consolidations can be judged. For the coarse-grained materials under -consolidation, of which dilatancy characteristics can be reflected well by the modified Rowe dilatancy equation.