基于网格化应力场的边坡滑移面搜索模型及应用

Search model of slope slip surface based on gridding stress field and its application

为了将数值计算方法有效地应用于边坡稳定性分析,建立一种基于应力场的网格式边坡滑移面搜索模型.首先,通过建立有限元分析模型求得边坡应力场,并提取单元坐标及各应力计算结果;其次,根据边坡模型几何尺寸建立直角坐标系,将边坡在平面内按网格式离散为n个方格,使每个网格内可包含一个或多个原有限单元网格;再次,通过编制程序提取边坡应力场,在每列网格内依据C-M屈服准则搜索出最可能达到屈服条件的有限单元并标记;同理依次搜索出各列潜在滑移单元并串联,即实现基于应力场的网格式边坡滑移面搜索模型.最后,选用国际经典边坡案例,依据矢量和法安全系数表达式,基于应力场网格式边坡滑移面搜索进行边坡稳定性分析与计算,并与传统方法进行对比分析,证明该方法可行性和优越性.该方法适用于非极限状下边坡稳定性的评价与分析,计算结果更为合理.

In order to effectively apply numerical calculation method to slope stability analysis,a mesh slope slip surface search model based on stress field is established.Firstly,the stress field of slope is obtained by establishing finite element analysis model,and the element coordinates and the stress calculation results are extracted.Secondly,a rectangular coordinate system is established according to the geometric size of the slope model,and the slope is discretized into n-grids in the plane according to the grid form,so that each grid can contain one or more original finite element grids.Thirdly,the stress field of the slope is extracted by programming,and the most likely finite element to reach the yield condition is searched and labeled in each grid according to the C-M yield criterion.Then,the potential slip elements are searched in parallel and in series,that is to say,the mesh slope slip surface search model based on stress field is realized.Finally,the international classical slope case is selected,and the slope stability is analyzed and calculated based on the expression of vector and normal safety factor.The method is compared with the traditional method and proved to be feasible and superior.This method is suitable for the evaluation and analysis of slope stability under non-limit shape,and the calculation results are more reasonable.