软弱基座陡崖上危岩崩落序列

Collapse sequence of perilous rock on cliffs with soft foundation

陡崖或陡坡下岩性差异风化形成的岩腔是危岩崩落的起因。群发性破坏机理必须考虑危岩体之间的相互作用。基于危岩块相互作用力学机制,采用危岩块转动角度来衡量危岩体之间的相互作用,计算出不考虑相互作用(含等效)时危岩体的转动角度,运用能量守恒原理得到各危岩体相互作用后的实际转动角度,由转动角度建立了各危岩体的等效弯矩计算式。基于断裂力学和损伤力学建立了危岩体崩落时间的计算方法,并通过计算实例初步验证了该方法的有效性。

Rock cells formed by the effects of different weathering of lithology of cliffs or steep slopes are the cause for collapse of perilous rock.The mechanism of massive failure must consider the interaction of perilous rock.Based on perilous rock mechanics,the interaction of perilous rock is estimated by rotation angle of the rock.First,the rotation angle without consideration of the interation of perilous rock（considering equivalent） is calculated.Then,the rotation angle with consideration of the interation of perilous rock by the law of conservation of energy is acquired.Finally,the formula to calculate the equivalent bending moment of rock by rotation angle is obtained.The formula to estimate the time for rock collapse based on the principle of fracture mechanics and damage mechanics is also established.