高山峡谷地区高陡边坡深部裂缝一般特征分析

中国西南部,尤其是水能资源较为集中的青藏高原周边地区是近期工程建设的热点地区。由于强烈的内外动力地质作用,这些地区形成了高山耸立、沟谷深切的地貌景观,高山峡谷区的高陡岩质斜坡变形与稳定将是工程建设所面临的主要工程地质问题之一。高陡边坡的变形与稳定对工程建设的可行性起到决定性作用,并影响着施工周期和工程造价。本文分析了深裂缝现象的一般特征,认为深裂缝是在特定地质环境下内外动力地质共同作用的产物,一般均具有三高、继生这一共性。在工程处理方面,深裂缝可按山体加固的方法进行工程处理,预应力锚固洞可较好处理深裂缝问题。

SPECTIAL CHARACTERISTICS OF DEEP FRACTURES IN HIGH AND STEEP SLOPES IN SOUTHWESTERN OF CHINA

The edge area of Qinghai-Tibet Platean in Southwestern of China is famous for its abundant water-power and will be an engineering construction center,. Because of complicated and intense intrinsic-extrinsic dynamical geology action, high and steep rock slopes are well developed in the area. These slopes show some distinguished characteristics. They are different from general rock slopes because of the special geological background. According to the data from field investigation, these slopes can be characterized as super height, high geostress and complicated deformation and failure evolution process. The deformation and stabilization of slopes decide whether a project is feasible, affect the time limit for a project and control the construction cost. This paper points out that the deep fractures are the result of the coupling of endorgenic and exogenic geological processes by unloading of river valley and releasing of high geostress. The slope structure, strong geostress, rock property and high steep topographical features provide material foundation for deep fractures. Finally, the paper studies how deep fractures affect human engineering construction, and analyzes how these fractures influence the leakage of reservoir and the stability of slope. The prestressed anchoring cavern and other mountain reinforcement methods can be used to tackle deep fractures.