复杂应力条件下饱和松砂振动孔隙水压力增长的能量模式

利用新研制的土工静力–动力液压三轴–扭转多功能剪切仪,针对相对密度为30%的饱和福建标准砂,进行了均等固结条件下的不排水循环单向剪切以及轴向和扭转双向耦合循环剪切等多种复杂循环剪切试验,并在控制不同的初始固结参数的三向非均等固结状态下,进行了循环扭剪试验。分别研究了循环剪切应力路径、初始主应力方向、初始偏应力比、初始中主应力系数等因素对孔压与累积耗散能关系的影响。初步建立了复杂应力条件下饱和松砂的孔隙水压力增长的能量模式。

Energy-based model of vibration-induced pore water pressure build-up of saturated loose sand under complex stress condition

The newly developed static and dynamic universal triaxial and torsional shear apparatus was used to perform different types of experimental test of saturated Fujian loose sand.The samples were subjected to cyclic torsional shear and cyclic vertical-and-torsional coupling shear with rotation of principal stress axes under isotropic consolidation as well as cyclic torsional shear under anisotropic consolidation condition with different initial consolidation parameters.The influence of cyclic shear stress path,orientation of initial major principal stress,initial ratio of deviatoric stress and initial coefficient of intermediate principal stress on the empirical relationship between vibration-induced pore water pressure and the accumulative energy dissipation during cyclic shear was investigated.The energy-based model of pore water pressure development for saturated loose sand under complex stress condition was preliminarily established.