Genetic models and influence factors of karst collapses in Loudi City of central Hunan,China
Loudi City in central Hunan has recorded 281 karst collapse incidents and tens of thousands of collapse pits,which made it one of the cities in China experiencing the most serious karst collapses.Among all these karst collapses,222 karst collapses occurred in mining areas,accounting for 79%of the total.In addition,some karst collapses were caused by foundation engineering or by rainfall infiltration and erosion.By sorting out the temporal and spatial relationship between karst collapse events,karst collapses and collapse pits,it is concluded that karst collapses in Loudi City can fall into four occurrence modes,namely,vacuum erosion,floating-softening,load vibration and seepage erosion,and each mode has four collapse processes.Among them,vacuum erosion collapses and floating-softening collapses are mainly caused by mining activities,which are induced by drainage from the mining area and backwater after the mine has been closed;load vibration collapses are mainly induced by external dynamic loads such as pile foundation construction;seepage erosion collapses are natural collapses mostly induced by heavy rainfall.The influencing factors of karst collapses include basic factors and inducing factors.The basic factors include stratum lithology,karst landform,karst water abundance,correlation with mining areas,etc.,which constitute the key influencing factors in karst collapse-prone areas;the inducing factors mainly include drainage in mining areas,backwatering in closed mines,engineering vibration,rainfall,etc.,and the intensities of these factors can affect the time,scope and scale of karst collapses.In order to strengthen the risk management of karst collapses,it is recommended to establish a monitoring and early warning system for karst collapses,and scientifically develop risk assessment,prevention and control plans and disaster emergency response plans for karst collapses.Besides,controlling the area,method and intensity of engineering construction,prohibiting or limiting the mining of coal,gypsum,groundwater,etc.in karst areas,and maintaining the dynamic balance between rock,soil,cave,water and air are effective measures to prevent and control karst collapses.In this paper,the distinction between the basic factors and inducing factors of karst collapses can provide a scientific basis for their effective prevention and control in karst areas,and can provide a reference for the construction of harmonious and beautiful villages.
karst collapsegenetic modelinfluence factorsmining activityLoudi City of central Hunan
万方数据
维普
