密度和围压对粗粒土力学性质的影响

 通过4组不同密度的粗粒土大型三轴压缩试验，研究了密度和围压对力学性质的影响。成果表明:对于同一种粗粒土，密度和围压是影响力学性质的重要因素，它们共同决定了粗粒土的应力应变曲线形态。疏松的粗粒土一般表现为应变硬化型和体积压缩，随着围压的增大，应力应变曲线的硬化特征更加明显，体缩变形也增大。密实的粗粒土在低围压下应力应变曲线一般呈软化型，且常常表现出较大的体胀变形；高围压下，则表现出硬化特征和体缩特征。密度相同时，围压越高，粗粒土的抗剪强度也越高；围压一定时，粗粒土的残余强度相同。初始孔隙比小的粗粒土在相同的应力状态下体积变形也较小。密度是决定初始弹性模量的根本因素，而剪切变形过程中弹性模量则是密度和应力状态共同决定的。三轴压缩试验条件下，剪应力引起的体积变形一般是先剪缩后剪胀的，其大小由密度和应力状态决定。

Influences of Density and Confining Pressure on Mechanical Properties for Coarse-grained soils

Influences of density and confining pressure on mechanical properties for coarse-grained soils were researched by four groups large-scale triaxial compression tests.The results show as follows: Density and confining pressure are important factors affect mechanical properties for one coarse-grained soil,and they decide the stress-strain curve shape.Loose coarse-grained soils usually behave strain hardening and volume shrinking,the hardening characteristic of stress-strain curve becomes distinct and the volum...