NON-PROBABILISTIC RELIABILITY CONVEX MODEL METHOD FOR STABILITY ANALYSIS OF SURROUNDING ROCK MASS OF UNDERGROUND STRUCTURE
岩体地下结构围岩稳定非概率可靠性的凸集合模型分析方法

In reliability analysis of stability of surrounding rock mass for underground engineering,due to the particular characteristics of physical and mechanical parameters of rock mass,the variation interval of these parameters can only be obtained based on rock mass classification,while it is very difficult to obtain probability density function and subjection function of these parameters for rockmass. Therefore,the stability and reliability of surrounding rock mass,calculated by traditional probabilistic statistics model and fuzzy probability model,only has theoretical significance. Based on the characteristics of surrounding rock mass of underground engineering,the convex model is adopted to simulate uncertainties of rock mass parameters and to change state equation into affine function. For the underground structure with specified design safety margin,the response output interval of structure can be calculated through affine function whose independent variable is defined in convex set. The stability and reliability of the surrounding rock mass of underground structure can be determined by comparing design safety interval with response output interval. For the underground structure without design safety margin, non-probabilistic stability reliability index is defined through the analysis of ratio of average value in limit state equation to its deviation on convex set. Probability density function and subjection function need not be fitted in non-probability convex model methods. Therefore,non-probability convex model methods need less information than traditional stability reliability analysis method. The analysis results of non-probability methods are more accurate than that of traditional method. The results of engineering analysis show the convex model method of non-probabilistic reliability is feasible.