Comprehensive geological prediction and risk assessment of covered karst ground collapse

To provide the basis for the prevention and control of Covered Karst Ground Collapse (CKGC), based on the mechanism of three types of ground collapse which are respectively hourglass, soil cave and soil flow, and combined karst development degree with collapse triggering factors, a comprehensive geological prediction and risk assessment method for CKGC are proposed in this paper. According to the characteristics of soil particles in deformation and collapse, the soil body on the soluble rock can basically be divided into 3 types as sand, clay soil and soft soil. The 9 kinds of karst geological structures are divided on the basis of the combination of above three types of soils. At first, according to the spatial distribution of the karst geological structures, a comprehensive geological prediction of karst ground collapse was made in combination of the degree of karst development with the possible trigger factors. As a result, the study area was divided into 3 zones, namely, high prone zone, medium prone zone and low prone zone. Secondly, based on the potential impact of collapse disaster to the surrounding environment, the CKGC risk assessment was also completed, which resulted in the study area to be divided into 3 zones too, i.e., high risk zone, medium risk zone and low risk zone. The geological theory basis for CKGC comprehensive geological prediction and risk assessment method is sufficient; and it has a good practicability and operability.