安徽省沿江地区典型岩溶塌陷区盖层—岩溶组合特征

Characteristics of caprock-karst combination in typical karst collapse area along the Yangtze River in Anhui Province

安徽省沿江地区(铜陵、池州、安庆)岩溶塌陷地质灾害较发育,无论是开展岩溶塌陷地质灾害防治,还是监测预警,都必须研究岩溶塌陷发育的地质环境条件,掌握岩溶塌陷区盖层工程地质特征、下伏碳酸盐岩岩溶发育特征以及盖层-岩溶组合关系。文章以安徽省沿江地区岩溶塌陷为研究对象,在全面收集和总结区内大量岩溶塌陷调查、勘查及监测资料,野外调查典型岩溶塌陷区的基础上,分析了典型岩溶塌陷区盖层工程地质特征、下伏碳酸盐岩岩溶发育特征,并进行概化处理,建立了岩溶塌陷的盖层-岩溶组合地质模型。研究表明:区内典型岩溶塌陷区的组合主要有7种类型,最易产生岩溶塌陷的组合为"第四系盖层为粉质黏土-砂砾卵石双层结构,下伏基岩岩溶发育中等以上";岩溶塌陷致塌机理主要为潜蚀致塌,其次为真空吸蚀致塌、振动致塌。

Along the Yangtze River area in the Anhui Province （Tongling, Chizhou, Anqing）, karst collapse geological disasters are developed. Whether it is to prevent and control geological disasters in karst collapse or to monitor and early predict, it is important to study the geological environment conditions of karst collapse and grasp the engineering geological characteristics of caprock, karst development characteristics of underlying carbonate rocks and the relationship between caprock and karst. This paper takes along the Yangtze River area in the Anhui Province karst collapse as research area. Based on comprehensive collection and collation of investigation and monitoring data of the karst collapses and field investigation in typical karst collapse area, the characteristics of caprock engineering geology and underlying carbonate karst were analyzed. Through conceptualization, geological model of the cap rocks together with underlying karst were established. Re- search results shows that there are 7 types of capping layer and karst combinations in the typical karst collapse area of which the most vulnerable to karst collapse is the type of the quaternary cover with silty clay and sandy gravel double-layer structure, and underlying medium karstified bedrocks. The mechanism of karst collapse is mainly submersible erosion induced collapse, followed by vacuum erosion induced collapse and vibration collapse.