摘要
三峡库区涉水滑坡众多,目前库岸滑坡空间发育规律及其影响因素尚不明确.收集三峡大坝至库尾江津长江两岸593处滑坡相关资料,选取地层岩性、斜坡结构、高程与坡度作为滑坡关键控制因素及库水作用这一诱发因素.沿三峡大坝追溯至库尾,根据不同影响因子把干流库岸进行分段研究,统计滑坡在各影响因子中的分布特征,分析其分布规律及内在机理,可得以下结论:(1)受不同岩组的工程地质性质差异,干流库岸稳定性差异较大,造成滑坡在空间分布上呈显著区域差异性与分带性特征;(2)在同一岩组的左、右两岸或上下游段滑坡发育密度呈明显局部差异性,其主要受斜坡结构影响,顺向坡中发育密度明显高于横向坡与逆向坡;(3)由于地形地貌条件及库水作用影响,滑坡后缘高程与坡度由库首至库尾逐渐降低,而前缘主要集中于100~175 m,滑坡复活变形的最主要诱发因素为库水位升降作用,当水位作用于滑坡中前部时影响效果最明显,影响时效随着滑坡逐年变形应力调整后逐渐减弱.研究结果为三峡库区滑坡防治提供了一定依据.
There are many wading landslides in Three Gorges reservoir area,however,the spatial distribution and influencing factors of these landslides are not yet clear.The relevant data of 593 landslides along the Yangtze River from Three Gorges Dam to Jiangjin city were collected in this study.The lithology,slope structure,elevation and slopes angle were selected as the key control factors and reservoir water was selected as inducing factor.The reservoir bank slope on both sides of the Yangtze River was divided into several sections according to different factors.The spatial distribution characteristics and its internal mechanism of landslides were analyzed.The results could be summarized as follows:(1)The macroscopic spatial distribution of landslides presents significant regional differences and zonation characteristics because of the engineering geological properties of different rock groups.(2)It also shows obvious local differences in the left and right sides or the upstream and downstream in the same rock group.This may be related to the slope structure.The density of landslides in the consequent slope is much higher than transverse slope or converse slope.(3)Due to the topographic conditions and the influence of the reservoir water,the elevation of trailing and slopes angle of the landslides are gradually reduced from the head to tail region.Landslides front elevation were mainly focused on100-175 m.The main inducing factor of landslide deformation was the fluctuation of reservoir water level.The effect was most significant when the water level fluctuated in front and middle of the landslide.The effect of the fluctuation of reservoir water level to landslide decreases gradually with the adjustment of deformation.The research results can facilitate the future prevention and controlling of landslides in Three Gorges reservoir area.
作者
李松林
许强
汤明高
朱冬雪
Li Songlin;Xu Qiang;Tang Minggao;Zhu Dongxue(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2020年第1期341-354,共14页
Earth Science
基金
国家自然科学基金重点项目(No.41630640)
国家创新研究群体科学基金项目(No.41521002).
关键词
三峡库区
滑坡分布
影响因子
GIS
滑坡密度
工程地质
Three Gorges reservoir area
landslides distribution
influencing factors
GIS
landslides density
engineering geology
