块石尺寸对土石混合体强度特性的影响研究

Study on the Effect of Rock Size on Strength Characteristics of Soil-rock Mixture

选择块石类型为卵砾石,土料为含砂低液限黏土,含石率为50%;通过室内中三轴试验研究了4种不同卵砾石尺寸下的土石混合体的强度及变形特征。试验结果表明:1不同卵砾石尺寸各围压下土石混合体的应力应变关系曲线为硬化型曲线;随着卵砾石尺寸的增大,试样的峰值强度减小,高围压下尤其显著;2不同卵砾石尺寸各围压下土石混合体的体积应变随着轴向应变的增加而增大,剪切过程中直至破坏试样一直处于剪缩状态;3土与卵砾石混合体的内摩擦角与卵砾石的分形维度近似符合抛物线函数关系变化。试验分析所得的研究结果,为深入研究土石混合体这类特殊的地质体提供一定的理论依据。

Soil-rock mixture is constituted by the gravel rock and the low liquid limit clay sand. Its rock content is 50%. By laboratory triaxial tests,the stress-strain,and deformation characteristics of the soil-rock mixture under four different sizes were studied. The results showed： Stress-strain curves are the hardening curve in the different confining pressure,the peak intensity of the sample decreases particularly under high confining pressure with the increase of the size; In the different confining pressure,different soil-rock mixtures volume change increases with axial strain,and it shrinks through the shearing process; The friction and the fractal dimension of rock is similar parabolic function. Test results obtained by analysis are conducive to study more in depth of the soil-rock mixture.