中文摘要：

＂5.12＂汶川地震触发了大量地质灾害,同时形成了大量震裂松动岩体,这些岩体除受控于自身节理裂隙和结构面,还受控于地震裂缝。极震区软岩崩塌十分发育,震裂斜坡岩体损伤大,借助西部交通科技项目和国家自然科学基金展开了对软岩崩塌的研究。基于对区域工程地质条件和震裂软岩裂隙和结构面组合的调查,阐述了崩塌危岩体的变形特征,进而采用赤平投影法和UDEC数值模拟对其成因机制和破坏模式进行了分析,在危岩体稳定性评价的基础上给出了防治措施建议。

英文摘要：

＂5.12＂ Wenchuan earthquake triggered a large number of geological hazards,and formed a large number of shattered loose rocks,in addition which are controlled by their own joints and structural surfaces,also controlled by the earthquake cracks.Soft-rock collapse develops very well in extreme earthquake area,and rocks suffered a large damage on shattered slope.With the western transportation projects and the National Natural Science Foundation of China,we launch a study of soft-rock collapse.Based on the investigation of the regional engineering geological conditions and the combination between joints and structural surfaces in the shattered soft rock,the deformation characteristics of dangerous rock mass are described in the paper.Thus through the use of stereographic projection and UDEC numerical simulation,the formation mechanism and failure mode are analyzed.Finally on the basis of stability evaluation of the dangerous rock mass,prevention measures are proposed.