摘要
广义Hoek-Brown(GH-B)强度准则作为估计完整岩石或节理岩体剪切强度的半经验准则,已成为岩体强度预测及数值计算领域中应用最广的准则之一。经验公式中涉及3个与岩体特性有关的材料参数mb、s和a,实际应用中还不能直接对这3个参数进行精确取值,只能通过中间变量推导或结合地质经验来确定。为尽可能大地消除因用H-B经验公式的中间变量推导带来的累积误差,消除边坡稳定性评价结果的偏差,本文提出了从基本随机变量着手,考虑基本变量的模糊性和随机性,通过模糊随机可靠性理论来综合分析评价边坡潜在破坏概率和风险程度的方法。首先从决定GH-B经验公式的4个基本参数GSI、σci、mi和D出发,采用模糊数对随机变量进行模糊化处理,然后引入到H-B经验公式中去,利用修正的模糊点估计方法将节理边坡的稳定极限方程由模糊集向普通随机集转化,求解边坡的模糊破坏概率。
The General Hoek-Brown(GH-B) strength criterion is used as a half experience criterion for confirmation of full rock or joint rock shear strength,which has become the most widely used criteria in the field of mass strength prediction and numerical calculation.Empirical formulas involve three material parameters,mb,s and a,which are relative to the characteristics of the rock mass.In practical application,they cannot be calculated directly,and they are only determined through the middle variable or with geological experience.In order to eliminate the H-B experience accumulative error during the middle variables derivation as much as possible and eliminate the deviation of the slope stability assessment results,a new method is put forward.We can examine the basic random variables,considering the fuzziness and the randomness of the basic variables.Through the fuzzy reliability theory,the slope failure probability and potential risk degree are analyzed and evaluated comprehensively.Starting from the four basic parameters GSI,σci,mi and D,which are middle variables to the GH-B experience formula,we use the fuzzy number to fuzzed the random variables,introduce them to the H-B experience formula,and use the modified fuzzy point estimation method to translate the slope limit equation.The translation takes the fuzzy set to ordinary random set.The fuzzy probability of the slope is solved.
出处
《水文地质工程地质》
CAS
CSCD
北大核心
2013年第3期41-47,共7页
Hydrogeology & Engineering Geology
基金
国家自然科学基金资助项目(41027001)
关键词
GH-B强度准则
模糊点估计法
节理边坡
模糊破坏概率
GH-B criterion
fuzzy point estimate method
joints slope
normal fuzzy number
fuzzy instability probability
