相对密实度对砾砂初始切线模量的影响

针对基坑施工过程中周边土体由于受到扰动而发生结构性变化,致使土体强度和变形特性改变这一问题,选取典型砾砂进行不同围压下的三轴固结排水剪切试验,得到砾砂DuncanChang模型的相关参数.探讨了砾砂的初始切线模量Ei对相对密实度D_r的影响规律,并应用数学手段对与Ei有关的无量纲参数K和D_r的关系进行拟合.结果表明,相对密实度Dr对砾砂的强度和变形特性有着重要影响,ln K与D_r大致呈二次函数关系.

Influence of relative density on initial tangential modulus of gravelly sand

In order to solve the problem that the structural change of surrounding soil due to the disturbance appears during the construction process of foundation pit and then the change of the strength-deformation characteristics of soil is induced, the typical gravelly sand was selected for the triaxial consolidation drained shear tests under different confining pressures. The related parameters for the Duncan-Chang model for the gravelly sand were obtained. The influence rule of initial tangential modulus E_i on the relative density D_r for the gravelly sand was investigated. In addition, the relationship between D_r and dimensionless parameter K which were related to E_i was fitted. The results show that the relative density D_r has important influence on the strength-deformation characteristics of gravelly sand, and the relationship between ln K and D_r can be describled by the quadratic function.