考虑非线性强度的无限长土坡渐进变形模拟

利用平面应变条件下均质无限长土坡坡土的应力分量,考虑坡土破坏的非线性特征,借鉴黏塑性理论过应力模型,通过拟定坡土滑移速度与黏塑性应变率之间的关系式,基于Cam-Clay模型推导出非线性Mohr-Coulomb破坏准则下坡土滑移速度和位移的显式表达式。针对2个边坡实例进行计算分析,结果表明:计算值与边坡实测数据和前人的研究成果吻合良好;非线性破坏准则的3个强度参数对无限长土坡的渐进变形有显著影响,随着非线性参数c₀减小、m增大、σ_t减小,边坡渐进变形逐渐增大,剪切层深度也不断增加。

Simulation of Progressive Deformation along Infinite-length Soil Slope in Consideration of Nonlinear Strength

The shear stress of homogeneous slope soil with infinite length under plane strain condition is obtainedand a nonlinear strength is incorporated into the overstress creep model. With Cam-clay model, the explicit expres-sions of slope soil’s sliding velocity and displacement are deducted following Mohr-Coulomb failure criterion by establishing the relationship between velocity or displacement and visco-plastic strain rate of the slope soil. Numerical calculation results agree with the field measured data. Parametric study on the nonlinear strength is also performed to investigate their influences on the creep or progressive deformation of soil slope. It is found that the progressive deformation of slope and thickness of shear zone both increase with the decrease of nonlinear parameters c₀ and σ_t and the increase of parameter m.