水位下降边坡的流-固耦合弹塑性分析

Fluid-solid Coupling Elasto-Plastic Model of Slope under Drawdown Condition

基于非饱和土流-固耦合理论,建立考虑塑性变形的水位下降边坡模型,研究土体的弹塑性对渗流场、应力场和位移场的影响,并与弹性边坡的耦合计算结果进行比较。结果表明,考虑土体弹塑性对边坡渗流场的影响不大,对应力场的影响主要在坡脚,弹塑性解能反映水位下降时坡脚应力集中向深部发展的现象,而弹性解无此现象;在弹塑性模型中,边坡位移场与饱和渗透系数和水位下降速度有关,且在坡脚更为显著。

Based on unsaturated fluid-solid coupling theory, a slope model considering plastic deformation under drawdown condition is established to study the effect of soil elasto-plasticity on seepage, stress and displacement, and the results are compared with that of elastic condition. The comparison shows that the elasto-plasticity of soil has little effect on seepage field,and for stress field, the effect is mainly distributed at slope toe. The elasto-plastic solution can reveal the phenomenon of stress concentration developing from slope toe to deep under drawdown, while the elastic solution has no this phenomenon. In elastoplastic model, the displacement field is affected by the permeability of slope and the water level drop rate, particularly at the toe of slope.