循环荷载下堆积体残余变形特性

Residual Deformation Behavior of Deposits under Cyclic Loading

通过大型动三轴试验研究堆积体在不同应力水平、不同循环荷载幅值下残余应变与振次的关系,同时进行不同初始条件下残余应变的对比。试验发现堆积体在循环荷载下的残余应变与lg(1+N)有较好的线性关系(N≤30),沈珠江经验公式适用于堆积体在循环荷载下累积残余应变的计算。初始条件对堆积体的残余应变有重要影响,饱和不排水条件下残余剪应变最大,饱和排水条件次之,风干排气条件最小。应用沈珠江残余应变公式进行堆积体循环荷载下残余变形计算时应选取与工程实际条件相匹配的参数。

Residual deformation behaviors of deposits under cyclic loading at different stress levels and cyclic loading amplitudes are studied by a large-scale dynamic triaxial test.The residual deformation of the deposits under different initial conditions is also discussed.Residual strains under cyclic loading are found to show a linear relationship with lg（1＋N）when Nis less than 30.Shen＇s empirical equation is suitable for calculating the residual strain of deposits under cyclic loading.The initial conditions have a significant effect on the residual strain of deposits.Residual shear strain is the largest under undrained conditions,medium under drained conditions,and smallest under air dried drainage conditions.When the residual deformation of the deposit under cyclic loading is calculated using Shen ＇s equation,the equation＇s parameters should match the actual engineering conditions.