循环荷载下尾矿粉土的孔隙水压力特性

为了解尾矿粉土在振动作用下的孔隙水压力特性,采用GDS动三轴试验系统对尾矿粉土进行了循环荷载试验,通过施加循环应力使尾矿粉土达到完全液化状态,研究了相对密度及固结围压对尾矿粉土孔隙水压力特性的影响.研究结果表明,尾矿粉土的孔压增长过程可分为4个阶段:孔压快速增长阶段、孔压稳定增长阶段、结构破坏阶段及完全液化阶段;相对密度及围压的增加可以提高其抗液化能力.对比尾矿粉土及砂土试验结果发现:循环荷载作用下尾矿粉土的孔隙水压力特性与砂土不同,其孔压增长规律可用一个双S型模型描述,该模型对粉土和砂土均具有较好的适用性.

Pore-Water Pressure Characteristics of Tailings Silt Under Cyclic Loading

A GDS dynamic triaxial testing system was used for cyclic loading test to study pore-water pressure behaviors in tailings silt. Cyclic stress was applied to liquefy the tailings silt. The influences of relative density and confining pressure on pore-water pressure in tailings silt were studied. The results showed that the development of pore-water pressure can be divided into four stages， namely rapidly growing stage， stabilized-increasing stage， structural failure stage and fully liquefied stage. The increase of confining pressure and relative density can strengthen the capacity of anti-liquefaction. The result of lab tests on tailings silt was compared with that on sand， it showed that the characteristic of dynamic pore-water pressure for tailings silt is different from that of sand， and it can be described with a double-S model which has a very good application in both tailings silt and sand.