朱鹏程，徐昊，李中明，吴少飞

摘 要 红层在我国分布广泛，其边坡稳定性是工程建设中经常面临的问题。红层通常孕育顺层缓倾滑坡地质灾害，具有规模大、隐蔽性强、成灾机理多样等特点。本文以醴陵市鸭塘水库滑坡为例，对其形成机制进行了分析，对其稳定性进行了评价。评价结果表明水库长期渗水是该滑坡发展的一个重要因素，其稳定性与后缘裂隙贯通率、滑带泥化率及后缘裂隙充水高度密切相关，超过临界值，坡体将会失稳。对以后红层区库区选址、设计蓄水位确定、防渗处理工作具有一定指导意义。

关键词 水库;缓倾滑坡;红层;形成机制;稳定性评价

中图分类号：P644.22 文献标识码：A

Formation Mechanism Analysis and Stability Evaluation of Slow-inclination-bedding Landslide in Red-beds of Yatang Reservoir

Zhu Pengcheng， Xu Hao， Li Zhongming， Wu Shaofei

（Team 214 of Hunan Nonferrous Metals Geological Exploration Bureau， Zhuzhou Hunan 412007）

Abstract： Red beds are widely distributed in China， and slope stability is often faced in engineering construction. The red beds usually leads to geological disasters of bedding gentle slope landslide， with the characteristics of large scale， high concealment and various disaster mechanisms. Yatang reservoir landslide in Liling City was taken as an example， formation mechanism was analyzed and its stability was evaluated. The results show that the long-term water seepage of the reservoir is an important factor in the development of landslide. The stability is closely related to penetration rate of trailing edge cracks， argillization rate of sliding zone and water filling height of the trailing edge cracks. When the parameter exceeds the critical value， the slope will lose stability.

Keywords： reservoir; slow-inclination landslide; red beds; formation mechanism; stability evaluation

紅层是指中生代以来的湖相、河流相、河湖交替相或是山麓洪积相等陆相碎屑沉积地层，多以软硬岩互层出现，以砂岩、泥岩、粉砂岩以及泥质岩、砂质岩为主[1]。由于其地质年龄较短，历经的构造运动较弱，岩层产状平缓，在工程建设中常被误认为稳定性良好，未及时处置。但红层岩体强度低、亲水性强、软硬互层、差异风化、易崩解的特性，反而造成地质灾害频发，常发生规模较大的顺层岩质滑坡。

针对红层滑坡，前人进行了广泛深入的研究。根据岩层倾向与坡向之间的夹角大小将缓倾红层边坡分为三类：顺层坡、顺层斜向坡、反向坡[2-3]，对其破坏模式及失稳机理进行了较为翔实的总结，但鲜有涉及库区红层边坡。本文在总结鸭塘水库滑坡地质环境条件、基本特征的基础上，对其形成机制及稳定性进行了分析和评价，以期为红层区类似水利工程规划建设及除险加固提供参考。……