基于矢量和方法的边坡稳定性分析中整体下滑趋势方向的探讨

Study on potential sliding direction in slope stability analysis based on vector sum method

矢量和分析方法是基于力是矢量这一基本概念的分析方法,其关键在于确定边坡真实应力分布状态及整体下滑趋势方向。在边坡一定的受力条件下,利用有限元方法得到边坡应力分布状态后,不同定义的下滑趋势方向就可以得到不同的边坡滑面位置及其对应的矢量和法安全系数,通过分析,提出了3种确定整体下滑趋势方向的方法并分别对固定滑面、非固定滑面及均质边坡圆弧滑面的搜索等进行了探讨,计算结果表明:由潜在滑面各点极限抗滑能力确定的边坡整体下滑趋势方向在临界滑面位置的搜索方面是合理的。最后给出了边坡矢量和分析方法平面问题与三维问题安全系数的统一表达式,公式简洁,容易编制程序并容易被工程技术人员掌握和应用。因此该方法在工程实践中有望得到广泛的应用。

Based on the fact that forces are vectors, the key problems of the vector sum method are the state of real stress distribution and potential sliding direction of slopes. In a slope under certain conditions, after the determination of stress distribution by FEM, different safety factors can be obtained by the vector sum method with different potential sliding directions of the slope. Three definations of the potential sliding direction of the slope are put forward, and then the fixed circular slip surfaces, non-fixed circular slip surfaces and circular slip surface searching are discussed respectively. It is shown that the potential sliding direction defined by anti-sliding capacity of the potential slip surface is the most reasonable of the three. Finally unified formula about the VF in 2D and 3D problems is presented. Its calculating process is very simple and it is very easy to be applied in practical engineering problems. So the vector sum method can be widely used in practice.