三峡库区香溪河流域滑坡类型及发育规律

The Development Law and Type of Xiangxi River Watershed in the Three Gorges Reservoir Area

三峡库区香溪河流域处在秭归向斜和黄陵背斜之间,地质环境脆弱,滑坡灾害频发,给香溪河流域村镇居民的生命财产安全及沿线公路的正常运营带来严重威胁。本文依据现场勘查,将滑坡分为两类,其中河流西侧的层状反向结构岸坡主要发育“弯曲-滑移”型滑坡,东侧的层状同向结构岸坡则发育“滑移-拉裂”型滑坡。对滑坡的空间分布状况、发育特征及数量作了统计与分析,结果表明:地形地貌是控制滑坡发育的因素之一,凸形坡、20°~40°的岸坡以及处于三面临空的凸岸山体均易发育滑坡;岩性与滑坡发育也有对应关系,泥砂岩互层的滑坡发育密度总体高于灰岩地层;滑坡发育尚与岸坡地质结构相关密切,泥砂岩互层同向结构岸坡的滑坡发育密度最高,泥砂岩互层反向结构岸坡孕育的滑坡规模最大;水库蓄水及公路建设是诱发滑坡的两大人为因素。

Xiangxi river watershed is located in the three gorges reservoir area between Zigui syncline and Huangling anticline.Its fragile geological environment and landslide disasters become a serious threat to the usual operation of highway and the safety of resident’s life and property.Based on the scene,the landslide is divided into two catego-ries,including bending-sliding landslide on the west side of the main river and the sliding-tension landslide on the eastern side of the main river.The space distribution,development characteristics and quantity of landslide are ana-lyzed.The results show that the topography is one of the controlling factors for the development of landslide.The con-vex slope,20 degrees to 40 degrees slope and convex mountain facing empty in three sides are easily slipped.There is a corresponding relationship between the lithology and the development of the landslide.The sandstone and mudstone interbedded is higher than limestone strata in landslide density.The formation of landslide is closely associated with the slope geological structure,mud sandstone interbedded with its structure to the slope landslide has the highest density,the mud sandstone interbedded with its structure reverse to the slope breeds the largest landslide.Reservoir and high-way construction is the two human factors of the formation of landslides.