考虑固废强度非线性的填埋场地基承载力分析

Bearing Capacity Analysis on Landfill Ground Considering the Nonlinear Shear Strength of Municipal Solid Waste

基于幂函数准则描述了固废的非线性强度特性,并分析了该准则随强度参数的变化规律。与基于摩擦角修正的非线性Mohr-Coulomb准则和二次函数非线性强度准则进行了对比,并探讨了将幂函数准则换算为线性Mohr-Coulomb准则得到的黏聚力和内摩擦角随应力的变化规律。通过与一系列直剪试验结果对比,验证了幂函数准则预测固废非线性强度的合理性。基于所建立的非线性强度准则,对填埋场地基承载力进行数值模拟,并通过与基于线性强度准则模拟结果对比,获得了固废强度非线性对承载力的影响规律。参数分析结果表明,地基承载力值对强度准则指数参数的变化更敏感。

Based on the power function criterion,the nonlinear shear strength of MSW（ municipal solid waste）and the variation with strength parameter were investigated. The feasibility of the criterion was validated by comparing to the second order form criterion and the modified Mohr-Coulomb criterion in which the friction angle is stressdependent. The varying characteristics of the obtained cohesion and friction angle by transforming to the linear MohrCoulomb criterion were studied. The proposed strength criterion was used to predict the shear strength of MSW obtained from direct shear tests,and the predicted results compare well with the experimental results. The proposed nonlinear strength criterion was applied to compute the bearing capacity of the landfill ground by FE modeling. By comparing to the computed results by linear criterion,the influence of strength nonlinearity on the bearing capacity was shown. Parametric studies show that the bearing capacity is more sensitive to the exponent parameter of strength criterion.