基于数字图像技术的土石混合体边坡稳定性分析

Stability analysis of soil-rock mixed slope based on digital image technology

土石混合体作为自然界中常见的一类岩土体,尤其在我国西南地区存在着不同成因及规模的土石混合体边坡,这些边坡的稳定性问题对于工程在施工及运营期间的安全性有着重要的意义。在传统的边坡稳定性分析中,通常将土石混合体边坡视为均质土坡,忽略其内部块石的存在,这给计算结果带来了很大的误差。运用数字图像处理技术,对西南地区一土石混合体边坡进行分析,建立其细观结构模型。在此基础上,运用有限元强度折减法开展相应的稳定性研究。结果表明,块石的存在使边坡内部应力场分布变得极其不均匀,计算搜索得到的滑动带具有明显的绕石特征,考虑块石时计算得到的稳定系数要较等效均质土坡的稳定系数高。

Soil-rock aggregate is a kind of common geomaterial,especially in southwest of China,there are different genetic types and different scales of soil-rock mixed slopes.The stability of these slopes is very important to the slope safety during the construction and the operation of engineering project.In the traditional slope stability analysis,soil-rock mixed slope is always regarded as homogeneous soil slope,and rock blocks are neglected.By this way,the result of slope stability analysis may have large error.Using digital image processing technique,a soil-rock mixed slope is analyzed,and its microstructure model is built.Then,by using FEM shear strength reduction method,the stability of the slope is analyzed based on its real structure.The results indicate that rock blocks make the internal stress field became very heterogeneous,the sliding zone of the soil-rock mixed slope obtained by shear strength reduction method is very zigzag.The stability factor of the soil-rock mixed slope based on its real structure model is higher than that of homogeneous soil slope.