长江经济带岩溶塌陷分布、成因及其对工程建设的影响

Distribution and causes of karst collapse in Yangtze River Economic Belt and its influence on engineering construction

[研究目的]岩溶塌陷是长江经济带主要环境地质问题之一,开展长江经济带岩溶塌陷分布、成因及其对工程建设的影响研究,对长江经济带立体综合交通走廊建设和新型城镇化建设地质环境安全保障具有重要意义。[研究方法]本文系统梳理了长江经济带岩溶塌陷研究成果,从岩溶环境特征、岩溶塌陷的成因类型和机制、发育及分布规律、对工程建设的影响及防控措施几个方面进行论述。[研究结果]研究结果表明,长江经济带岩溶塌陷易发区面积约25.4万km^(2),有记录的岩溶塌陷灾害2146处,矿山疏干排水、抽水、工程施工等是这一地区岩溶塌陷的主要诱发因素。长江经济带岩溶塌陷具有以下发育分布规律:一是具有区域性和地带性的分布特征;二是发育地层一般为均匀状纯碳酸盐岩,沿断裂破碎带、褶皱轴部裂隙发育带、可溶岩与非可溶岩接触地带等岩溶洞隙密集发育带分布;三是多发生在岩溶地下水强径流带、河流两岸等地下水位变化幅度大、水动力条件易发生急剧变化的地段;四是多发生在人类工程活动强烈的地区,塌陷的规模取决于人类活动的性质和强度。为了降低岩溶塌陷对工程建设和安全运营影响,本文同时提出了相关建议和对策。[结论]长江经济带岩溶塌陷分布广、危害大,高易发区内线性工程、重要城市群等规划建设应对这一环境地质问题引起重视,该研究成果可为长江经济带国土空间规划、地质灾害防治提供基础支撑和理论依据。

[Objective]Karst collapse is one of the main environmental geological problems in the Yangtze River Economic Belt.Conducting research on the distribution,causes,and impact on engineering construction of karst collapse in the Yangtze River Economic Belt is of great significance for the geological environment safety guarantee faced by the construction of multimodal transport corridor and urbanization in the Yangtze River Economic Belt.[Methods]This article systematically summarizes the survey results of karst collapse implemented by China Geological Survey since 2016,including the geological background,cause types and mechanisms,development and distribution patterns,impact on engineering construction,and prevention and control measures of karst collapse.[Results]The research results indicate that the area of potential karst collapse in the Yangtze River Economic Belt is about 254000 square kilometers,with 2146 documented karst collapse disasters events.Mine drainage,pumping and engineering construction are the main inducing factors for karst collapse in this area.The karst collapse in the Yangtze River Economic Belt has the following formation and distribution characteristics:firstly,it has regional and zonal distribution characteristics;The second is that the underlying strata are generally homogeneous pure carbonate rocks,distributed along strong karstification zones such as fault fracture zones,the axis of strata fold and contact zones between soluble and non-soluble rocks;Thirdly,it often occurs in areas with large amplitude,high speed,and high frequency of groundwater level fluctuation such as concentrated flow zone of karst and river terraces;Finally,it often occurs in areas with strong human engineering activities,and the scale and quantity mainly depend on the type and intensity of human activities.In order to reduce the impact of karst collapse on engineering,this article also proposes relevant suggestions and countermeasures.[Conclusions]The karst collapse in the Yangtze River Economic Belt is widely distributed and has a great impact.The planning and construction of linear engineering and Megalopolis in high risk areas should pay attention to this issue.The research results can provide basic support and theoretical basis for the spatial planning of the Yangtze River Economic Belt and the prevention and control of geological disasters.