汶川地震崩滑灾害影响因素分析

为研究汶川地震崩滑灾害主要影响因素,在掌握汶川地震灾区公路沿线地震崩滑灾害资料基础上,选取典型段进行灾害统计分析,研究表明动力条件下斜坡失稳主要受斜坡岩体结构特征、地震动峰值加速度和斜坡动力响应特征三方面因素影响。地震动峰值加速度越高,地震崩滑灾害越发育。斜坡动力响应特征主要取决于地形地貌和地层岩性,陡坡硬岩段为地震崩滑灾害高发区。斜坡岩体结构是控制斜坡变形破坏的主要因素,从研究斜坡动力失稳角度,提出了斜坡岩体结构类型的划分,分为土层及强风化层——基岩二元结构、块状结构、层状及似层状结构、碎裂结构、土层等5个大类12个亚类。

Analysis of the influence factors of the landslides and rock falls induced by the Wenchuan earthquake

Based on the investigation information along the highway with a total length about 3 200km in the earthquake area,through statistical analysis of typical sections,study the influence factors of earthquake induced landslides and rock falls.The study shows that the earthquake induced slope failure mainly influenced by three factors,that is slope geological structure,Peak ground acceleration and response feature of slope to the earthquake.The higher of peak acceleration of ground motion,the earthquake induced landslides and collapse were more developed.response feature of slope to the earthquake are depends on the topography and stratum lithologies,the steep and hard rock slope are the high incidence areas of seismic geo-hazards.Under the dynamic conditions,the slope structures are also the main control factors to the deformation and destroy of the slope.For the study of slope dynamic instability,five geologic structure models are put forward.There are rock-soil and strong weathered rock structure,block structure,layered structure and quasi-lamellar structure,cataclastic texture,soil layers,and twelve sub geologic structure models.