基于赤平投影和有限元法的危岩稳定性分析

Analysis of dangerous rock stability based on stereographic projection and finite element method

危岩稳定性的评价方法主要有理论计算分析和现场地质调查。以贵州省贵阳市贵安新区高峰镇麻郎村石头寨组危岩崩塌为例,采用现场地质调查、赤平投影和有限元法对危岩的稳定性进行了分析,重点研究了结构面位置、裂隙水压力和地震3个因素对该危岩稳定性的影响。研究结果表明,结构面位置对崩塌的形成有一定的影响,危岩稳定系数与块体的体积和结构面贯通度有关系;暴雨工况下,由于岩体裂缝变化出现崩塌的频率较大,因此需对其进行关注并持续评价预测;地震工况下,处于结构面影响范围内所有的块体均产生较大的塑性应变及位移,易造成整个区域的垮塌。

The evaluation method for dangerous rock stability mainly includes theoretic calculation and analysis and site geological survey.Taking for example the collapse of dangerous rock in Guiyang city,field geological investigation,stereographic projection and finite element method are adopted to analyze stability of the dangerous rock,and the influence of three factors including the structure surface position,fissure water pressure and earthquake on stability of the dangerous rock is studied emphatically.The research result shows that,the structure surface position has certain influence on the collapse,the dangerous rock stability coefficient is related to block mass and persistence degree of the structure surface.Under the storm working conditions,as the collapse occurs frequently due to rock crack change,it is necessary to pay attention to this and give evaluation and prediction persistently.Under the earthquake working conditions,all the blocks within the structure surface influence range produce great plastic strain and displacement,which easily causes the collapse of the whole area.Through study,the theoretical basis can be provided for collapse prevention engineering design.