基于岩体质量指标Q分类系统的风险分析方法

A Risk Analysis Method in Rock Mass Quality Classification Based on Q System

基于岩体质量指标Q分类系统,应用Monte-Carlo模拟技术,研究了岩体质量风险分析方法。该方法视Q分类系统中各单因素取值为随机变量,建立了各单因素取值概率模型;通过对所建模型的抽样计算,可获取所评价岩体实际Q值小于设计所采用Q值的概率;通过对比分析Q值累计曲线和岩体质量分布图,可得到任意Q值对应的风险概率,查清岩体中可能出现的质量等级以及每个质量等级所占百分比的情况。本文研究成果已在青岛胶州湾海底隧道工程中得到应用,并获得良好效果。

A risk analysis method in rock mass quality classification based on Q system was studied, by using Monte-Carlo simulation technique in this article. All factors in Q system are treated as random variables in this method. By using the probabilistic models of these factors, the probability of the case that the Q value of the rock mass is poorer than that used in the design is adopted. The risk probability of each Q value, the grade of rock mass quality which may be appeared in rock mass and the percent of each grade can be got by analyzing Q value cumulative cure and rock mass quality distribution chart, which was proposed in this article. This method acquired good results in application to the Qingdao Jiao Zhou Bay cross-harbor tunnel project.