基于结构面网络模拟的节理岩质边坡可靠性分析

JOINT NETWORK SIMULATION BASED RELIABILITY ANALYSIS FOR JOINTED ROCK SLOPES

在节理岩质边坡的稳定性分析中,往往很少考虑结构面的随机分布特征。结构面网络模拟能较好地模拟结构面的随机分布,因此,本文将结构面网络模拟应用于节理岩质边坡的稳定性分析中。首先,运用岩体结构面网络模拟技术,建立岩质边坡的结构面网络模型。然后,将模拟的结果与有限元强度折减法相结合求取边坡的安全系数。最后,对边坡进行一定次数的结构面网络模拟并得到对应的安全系数,进而进行节理岩质边坡的可靠性分析。工程实例结果表明:(1)节理岩质边坡的稳定性主要受坡面附近结构面的数量及切割组合关系影响,结构面的数量越多,连通情况越好,则边坡稳定性安全系数越小;(2)该边坡的平均稳定性安全系数为3.06,失效概率为5%,表明该边坡有较高的可靠性,这与实际情况比较一致。本文的分析方法主要考虑了结构面的随机分布特征,能为节理岩质边坡的稳定性分析提供一条新的思路和方法。

The random distribution characteristic of discontinuities is always rarely considered when analysing the stability of jointed rock slope.Joint network simulation can simulate the random distribution of discontinuities.So this method is applied to analysing the stability of jointed rock slopes.Firstly,the joint network simulation method is used to establish the joint network model of the slope.Then the result is combined with shear strength reduction method to calculate the safety factor of the slope.Subsequently,many joint network simulations and their relative safety factors are used to analyse the reliability of the slope.The result of a real project shows the following.（1 ）The stability of the rock slope is mainly controlled by the quantity and combination relationship of discontinuities.The more is the discontinuities＇ quantity and persistence,the lower is the slope＇s safety factor.（2）The average safety factor of the slope is 3.06 and its probability of failure is 5%,which indicate the good reliability of the slope.This result is in accordance with the real condition of the slope.The analysis method in this paper mainly considers the＆nbsp;random distribution of discontinuities,and it presents a new way to analyse the stability of jointed rock slope.