坠落式危岩崩落的激振效应与求解

Contribution ratio of excitation action triggered by collopse of perilous rock to stability of perilous rock

群发性危岩破坏机理必须考虑危岩体之间的相互作用,研究危岩体崩落瞬时产生的激振波对相邻危岩稳定性影响具有重要意义。针对坠落式危岩,建立考虑危岩崩落激振效应物理模型,分析了危岩崩落激振波以正入射危岩主控结构面的受力特征;运用断裂力学方法,考虑自重和裂隙水压力影响因素下,构建了考虑危岩崩落激振作用的主控结构面联合应力强度因子计算方法。通过工程实例分析表明,考虑危岩崩落激振效应后,在天然和暴雨两种工况下应力强度因子值都有明显增加趋势,崩落激振波以竖直方向传播比水平方向山体里传播影响要显著。其研究成果对实施危岩防灾减灾提供了重要的科学依据。

The failure mechanism of perilous rock must consider the interaction between perilous rocks.Study on stability of perilous rock with excitation action triggered by collopse is very important.Here,aiming at falling perilous rocks,a physical model was established considering falling excitation action;its dominant fissure＇s mechanic characteristics under vertical incidence of excitation waves were analyzed;based on the fracture mechanics,a method to calculate the combined stress intensity factor of the dominant fissure under falling excitation action of perilous rock was established.The instance results showed that under conditions of nature and rainfall,the stability coefficients are reduced,specially,in horizontal direction;the stability coefficient decreases about 10% in horizontal direction,but about 2% in vertical direction.The results provided a scientific basis for disaster prevention and mitigation of perilous rock.