三维极限平衡分析在排土场稳定性分析中的应用

Application of three-dimensional limit equilibrium analysis to stability analysis of dumps

边坡二维稳定性分析方法中,边坡的端部效应、滑面的侧向弯曲、边坡的平面弯曲以及侧向的非均质性等因素常常被忽略了。排土场边坡对于由排弃松软岩石软弱夹层或沿地基表面产生的滑坡其滑面具有不规则性,端部效应明显。为此,将二维简化毕肖普法扩展到三维进行排土场稳定性分析,由于该方法忽略了分条间垂向剪力的作用,对它进行三维扩展时也不需要采用多于其二维方法中所做出的假设,计算方法简单有效,适用范围较为广泛。计算表明应用三维稳定性分析方法求得的安全系数大于二维计算值,这是符合实际的。

For two-dimensional slope stability analysis method, such issues as the end effect of slope, the lateral bending of sliding surface, the plane bending of slope, and the lateral heterogeneity are often ignored. Due to the soft inter-layers generated by the abandoned soft rocks or the sliding slope along the ground, the slopes of the dump are irregular with obvious end effects. To this end, the two-dimensional simplified Bishop method is extended to be three-dimensional to make a stability analysis for the dump. Since this method ignores the effect of the vertical shear between different blocks, it does not require the assumptions made in two-dimensional method during the extending process, with the feature of simple calculation and effective in wide range. The calculations show that the safety factor obtained by three-dimensional stability analysis is higher than that by two-dimensional calculation, and is more practical.