边坡土体稳定性分析的数值流形方法

Numerical Manifold Method of Soil Slope Stability Analysis

为了了解边(壁)土体在未经支护前可能出现的变形趋势,采用数值流形方法,通过构造覆盖函数,将块体单元的形心位移与位移权函数有机结合起来,把每一个分割的块体视同为一个流形单元,通过权重函数来确定每一个块体单元在边坡流失时所起的作用即贡献值,依此来解析土体的应力 应变关系;应用弹塑性理论和参变量变分原理,建立了边坡(壁)土体变化趋势的状态方程,并给出了方程的求解过程。结合具体实例研究了地质体的应力 应变变化趋势。研究结果表明:利用块体单元的形心位移及其位移权函数能较好地反映边坡失稳瞬间所发生的应力释放、应力转移和应力重新分配的特征。

In order to understand the deformation tendency caused by soil slope before non-protection, numerical manifold method was used to constitute cover function which could combine center displacement of block element with its displacement weight function, treat each segmental u-nit as one manifold unit whose weight function could make its effect when soil slope was deformed, and analyzed the relationship between stress and strain in the soil. According to elastic-plastic theory and parametric variational principle, the state-equations of the deformation tendency for slope were found and the course which disposed of these state-equations was presented. According to a concrete case, the deformation tendency of all geologic body was calculated. The results indicate that this method can effectively reflect the characteristic whose stress would release and transfer and redistribute when soil slope deforms.