摘要
我国西南有世界上最大的连片裸露岩溶山区,受极端气候变化和大规模人类工程活动的持续影响,特大岩溶滑坡频发;80%以上滑坡的发生与地下水有密切关系。当前,地下水对滑坡影响作用的研究主要针对非岩溶区,对于岩溶山区则相对研究较少,岩溶山区特大滑坡失稳机理和新型成灾模式理论研究成为亟待解决的重大前沿科学问题。本文以贵州省威宁县猴场岩溶石山大型滑坡为研究对象,通过对滑坡区域岩溶发育特征、水文地质条件调查与分析,结合Google卫星图像对比,取得主要结论:(1)滑坡区灰岩与下伏碎屑岩接触带岩溶强发育,接触带上的岩溶空间以及煤层采空区是岩层下沉或滑坡基本影响因素;(2)滑坡区后缘垂直裂隙是由褶皱构造所形成经后期营造和本次扰动叠加作用后形成大型拉裂缝,这些裂缝是导致不同区域岩层失稳下沉或滑坡的另一个基本影响因素;(3)提出和建立负压水动力场对滑坡或岩层下沉的影响作用新型成灾模式,对西南岩溶石山滑坡成因研究,以及提升岩溶山区地质灾害防灾减灾具有一定意义。
Southwest China has the largest contiguous mountain area of exposed karst in the world;Under the circumstances of extreme climate change and large-scale human engineering activities,extremely large karst landslides occur frequently there.The occurrence of more than 80%of landslides is closely related to groundwater.At present,the research on the effect of groundwater on landslides is mainly aimed at non-karst areas,but there are relatively few studies on karst mountain areas.The theoretical investigation on the instability of mega-landslides in karst mountain areas and the updated theory of disaster-forming modes has become a major frontier scientific concern.In this study,a large karst landslide occurred at Houchang,Weining County,Guizhou Province,China,was targeted for a case study.Through field investigation and analysis of karst development characteristics,hydrogeological conditions in the landslide area,and comparison of Google satellite images,the main conclusions are reached:(1)Karst was strongly developed in the contact zone between limestone and underlying clastic rock in the landslide area,and the existence of karst space and coal seam goaf in the contact zone were the principal influencing factors of rock subsidence or landslide;(2)The vertical fissures at the rear edge of the landslide area were initially formed by folded structures;Then large tensile fissures were developed as the joint results of post-reformation and superimposition of engineering disturbance.These fissures were another noticeable influencing factor that caused rock instability and subsidence or landslides in different regions;(3)It is of great significance to propose and establish a new disaster-forming mode associated with the influence of negative pressure hydrodynamic field on landslides or rock subsiding.This research would facilitate the study of the causes of karst landslides in southwest China,and enhance the prevention and mitigation of geological disasters in karst mountain areas.
作者
易连兴
YI Lianxing(Key Laboratory of Karst Dynamics, Ministry of Natural Resources, Institute of Karst of Geology, CAGS, Guilin 541004, Guangxi, China)
出处
《山地学报》
CSCD
北大核心
2020年第5期691-698,共8页
Mountain Research
基金
国家重点研发计划项目(2018YFC1504800)。
关键词
猴场滑坡
岩溶石山
负压水动力场
新型成灾模式
Houchang landslide in Weining
Karst mountain
negative pressure hydrodynamic field
new disaster mode
