基于极限平衡方程和水文模拟的坡体稳定性分析

Analysis of Slope Stability Based on the Limit Equilibrium Equation and the Hydrological Simulation

基于极限平衡方程,在安全系数F_s=1的条件下,推导了潜在的不稳定坡体判识公式,形成了潜在不稳定坡体的判识方法;基于水文模拟,分析了不同降水条件下坡体的饱和因子w的变化规律,并依据极限平衡方程进一步分析了潜在不稳定坡体的稳定性,建立了对潜在不稳定坡体稳定性的评价方法.以汶川地震灾区(四川省境内)为研究区,对区域内的潜在不稳定坡体进行了判识,判识出来的潜在不稳定坡体面积约为4 554.94km^2,占研究区总面积的14.32%.对判识出来的潜在不稳定坡体在不同重现期降水作用下的稳定性进行了评估,确定了可能形成滑坡的坡体分布.这一评估结果可为研究区的滑坡防范提供依据,降低滑坡灾害带来的生命和财产损失.

A deterministic formula for potential instable slope was derived from the limit equilibrium equation in the condition of the safety factor F_s=1 and the identified method for this kind of slope was then proposed here following the deriving process.Based on the hydrological process simulation,the variation rule of the saturated index w has been analyzed with different rainfall data inputs,and with this variation rule,the potential instable slopes were further analyzed,and the assessing method of potential instable slopes was established here.Taking the Wenchuan seismic disastrous area within Sichuan Province as the study zone,the potential unstable slopes has been identified by using the identified formula.The results show that the area of identified potential unstable slopes in this region is about 4 554.94km^2 accounting for 14.32% of the total area of the study zone.The further analysis of the stability of these identified potential unstable slopes under the action of the rainfall with different designed frequencies has been assessed,and the slope distribution with the possibility that the landslides may occur has been identified.This assessing result can provide the prevention basis for the landslides in the study zone and decrease the life and property loss caused by the landslides.