贵州武陵山区中二叠统崩塌地质灾害形成机理研究

为掌握贵州武陵山区中二叠统地层崩塌地质灾害发生机理，通过实地调查，结合原有地质资料，发现中二叠统主要分布在乌江及其支流两岸，典型的河谷地形为地层崩塌提供条件。分析认为，卸荷作用导致河谷岩体形成垂向的卸荷裂隙，卸荷裂隙在自重、水的侵蚀及溶蚀等外力的共同作用下，不断扩展，形成危岩体的边界，同时卸荷裂隙与层面、节理等结构面将岩体切割成独立的危岩体，从而导致崩塌灾害发生。指出该区域内二叠系中统三种崩塌破坏模式:卸荷—拉裂—倾倒式、卸荷—拉裂—滑移式、卸荷—拉裂—坠落式，而研究区内主要破坏方式为卸荷—拉裂—倾倒式。 

Mechanism of geological hazards in the middle Permian collapse in the Wulingshan mountains of Guizhou Province

The objective of this work is to analyze the mechanism of geological hazards of middle Permian collapse in the Wulingshan mountains, Guizhou Province. Based on field investigation and available geological data, it is found that the middle Permian strata in this area is mainly distributed on both banks of Wujiang river and its tributaries. The typical river valley terrain essentially causes the collapse. According to the analysis, the unloading action leads to the formation of vertical fractures in rock mass. These unloading fractures expand steadily under the combination of gravity, water erosion and dissolution, and other external forces, forming the boundary of dangerous rock mass. In the meantime, the unloading fractures together with independent structural planes such as layers and joints cut rock mass into independent dangerous rock masses, which leads to collapse. Three main types of failure modes of the Permian collapse in the region are proposed, unloading-stretching-overturn, unloading-stretching-sliding, and unloading-stretching-falling, of which the first type dominates the collapse in the study area.