危岩主控结构面疲劳断裂寿命计算方法

危岩的破坏机理和安全性受控于危岩主控结构面．通过计算危岩主控结构面在自重、裂隙水压力及地震力作用下的Ⅰ型及Ⅱ型应力强度因子，建立了主控结构面临界长度计算方法；把主控结构面内的裂隙水压力视作交变荷载，通过计算其对主控结构面应力强度因子的贡献，遵循P-M准则运用Paris疲劳方程建立了处于临界状态条件下主控结构面的疲劳断裂寿命计算方法，并通过疲劳断裂试验确定了三峡库区万州地区典型长石石英砂岩的疲劳系数C值和m值．

Method to Calculate Fatigue Fracture Life of Control Fissure in Perilous Rock

Rupture and safety of perilous rock are dominated by control fissure behind perilous rock block.Based on model-Ⅰ and mode-Ⅱ stress strength factors of control fissure under acting of weight of perilous rock,water pressure in control fissure and earthquake forces,method to calculate critical length of control fissure is established.Water pressure in control fissure is taken as a variable periodic load,and abiding by P-M criterion,when control fissure is filled with water method is established to calculate fatigue fracture life of control fissure in critical status by contributing value of stress strength factor stemming from water pressure of control fissure in Paris's fatigue equation.Further,parameters C and m of sandstone with quartz and feldspar in the area of the Three Gorges Reservoir of China are obtained by fatigue fracture testing.