水库土石坝填土料冻融交替下UU试验力学特征影响分析研究

Analysis on UU test mechanical characteristics of earth-rock dam fill material under freeze-thaw alternation

为研究水库土石坝填筑料土体的力学特征影响特性,设计孔隙度、冻融交替次数下的UU试验,获得了两因素下土体力学特征变化规律。冻融次数、孔隙度均抑制土体应力水平。土体变形阶段拐点应变不受冻融次数影响,但孔隙度增大,可造成拐点滞后,且孔隙度增大,可引起土体线弹性变形能力降低。两抗剪参数与孔隙度均为负相关关系,且冻融交替次数不影响两抗剪参数随孔隙度变化幅度,孔隙度增大2%,黏聚力、内摩擦角平均降幅分别为24.2%、11.1%;黏聚力与冻融次数具有二次函数关系,内摩擦角受冻融影响较小。研究成果可为土石坝等水利工程中填土料土体力学特征影响规律提供一定参考。

In order to study the influence characteristics of the mechanical characteristics of the filling material of the earth-rock dam of the reservoir,the UU test under the porosity and the number of freeze-thaw cycles was designed,and the change law of the mechanical characteristics of the soil under two factors was obtained.The number of freeze-thaw cycles and porosity inhibit the soil stress level.The strain at the inflection point in the soil deformation stage is not affected by the number of freeze-thaw cycles,but the increase in porosity can cause the inflection point to lag,and the increase in porosity can cause the linear elastic deformation of the?soil to decrease.The two shear parameters and porosity are in a negative correlation,and the number of freeze-thaw cycles does not affect the variation of the two shear parameters with porosity.The porosity increases by 2%,and the average decrease in cohesion and internal friction angle is 24.2%,11.1%.The cohesion has a quadratic function relationship with the number of freeze-thaw cycles,and the internal friction angle is less affected by freeze-thaw cycles.The research results can provide a certain reference for the influence law of the mechanical characteristics of the fill material in water conservancy projects such as earth-rock dams.