基于蒙特卡洛法的土石坝坝坡稳定分析研究  

Monte Carlo method-based study on slope stability analysis of earth-rockfill dam

作　　者：赵生华 李红军[2] ZHAO Shenghua;LI Hongjun(Jinchang Water Investment Co.,Ltd.,Jinchang 737100,Gansu,China;China Institute of Water Resources and Hydropower Research,Beijing 100048,China)

机构地区：[1]金昌市水务投资有限责任公司,甘肃金昌737100 [2]中国水利水电科学研究院,北京100048

出　　处：《水利水电技术（中英文）》2021年第7期167-174,共8页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金项目(51979292)。

摘　　要：土石坝坝坡稳定分析中通常采用的单一安全系数方法忽略了实际工程材料的变异性和不确定性,从而导致土石坝工程坝坡的安全水平不清楚,无法提供工程安全度的合理的评价指标。为此,需将可靠度分析引入土石坝坝坡稳定性安全评价体系。通过一个均质坝坡算例和工程实例的应用,利用蒙特卡洛法研究了影响坝坡稳定性可靠度指标的主要因素,包括随机变量的概率分布和相关性、土体参数的均值和变异性,进而将确定性方法得到的单一安全系数与基于可靠度分析方法得到的坝坡稳定分析评价结果进行比较。分析结果表明:当求解安全系数中包含较大的不确定性时,确定性方法往往无法正确反映边坡的实际安全状况,而可靠性分析可估计不确定性因素的总体影响,区分随机变量的不确定性量级,有利于设计人员更准确地评估土石坝边坡的安全等级,为坝坡设计和加固措施的制定提供科学依据。The method of the single safety coefficient usually adopted in the stability analysis of the earth-rockfill dam slope neglects the variability and uncertainty of the actual construction materials,and then leads to the indistinction of the safety level of the earth-rockfill dam slope,thus is unable to provide the reasonable evaluation indexes for the safety degree of the relevant project.Therefore,the relevant reliability analysis is necessary to be introduced into the safety evaluation system for the slope stability of earth-rockfill dam.Through the calculation case of the slope of a homogeneous earth-rockfill dam and the relevant engineering application of the actual case,the main factors affecting the reliability indexes of the dam slope,including the probability distributions and the correlations of random variables,the mean values and variabilities of the earth mass parameters,are studied herein with Monte Carlo method,and then the single safety coefficient obtained from the deterministic method is compared with the evaluation result of the dam slope stability analysis obtained from the reliability analysis method.The analysis results show that when great uncertainty is included in the solution of the safety coefficient,the actual safety status of the dam slope cannot be correctly reflected by the deterministic method in most cases,but the reliability analysis cannot only estimate the overall impact from the relevant uncertainty factors,but also can distinguish the uncertainty magnitudes of the relevant random variables,thus it is helpful for the designers to more accurately evaluate the safety level of the earth-rockfill dam slope,and then provide scientific basis for the designing the dam slope and making the relevant strengthening measures.

关 键 词：可靠性分析 土石坝 随机变量 安全系数 

分 类 号：TV641.2[水利工程—水利水电工程]