两端截尾概率分布下围岩可靠度研究

岩体工程的安全性设计通常采用可靠度和可靠指标进行设计,可靠度计算中的随机变量参数通常取-∞到+∞,而岩体参数是不可能为负或者无穷大的。为此,借助理论分布,提出了两端截尾概率分布下围岩可靠度计算的应力—强度干涉模型。并利用该干涉模型建立了参数为正态分布下的可靠度计算公式。应用该方法对康家湾铅锌金矿一巷道围岩进行了可靠度计算。实例表明:两端截尾概率分布的取值更加符合岩体力学参数的实际取值,同时可靠度也相应提高,模拟次数减少,收敛速度加快。从而为矿体围岩的安全性设计提供理论依据。

Research on the Reliability Calculation of Wall-rock under Two-end Truncated Probability Distribution

The safety design of rock mass engineering is usually made according to the reliability and reliability index of rock mass,and the random variable parameter is generally from-∞ to +∞ in the reliability calculation.But,the parameters of rock-mass are impossible to be negative or infinite.Therefore,a stress-strength interference model for the reliability calculation of rock mass under two-end truncated probability distribution was proposed with the help of distribution theories.On the basis of the model,a formula of reliability calculation was established when the parameters of rock-mass were subjected to normal distribution.An example for the reliability calculation of wall rock was given in Kangjiawan Lead,Zinc and Gold Mine.The results show that the sampling of rock-mass mechanical parameters under two-end truncated probability distribution more accords with the actual value.Simultaneously,the reliability is also increased,the analogue times are reduced,and the speed of convergence is quickened.This research would provide theoretical basis for the security design of rock-mass.