Monitoring technique and its application of karst groundwater-air pressure in karst collapse

Monitoring and prediction for karst collapse has always been a worldwide problem. The main reason is that the monitoring technique for dynamic condition of karst collapse is still used by traditional method of groundwater level monitoring, of which the period is long and the groundwater table is connected with atmospheric pressure. A new monitoring technique for sudden karst collapse has been proposed by scientific research group of Institute of Karst Geology,CAGS,named karst groundwater-air pressure monitoring technique, which can both really reflect the change conditions of groundwater-air pressure within karst fracture and conduit system, and provide a basis for the research of collapse mechanism formation, monitoring and early warning. This technique has special requirements for drilling, sealing on the top of borehole, and monitoring frequency, which is simple in installation, convenient in operation and low in cost. After more than 20 years, the technique has been improved and successfully applied to 11 typical karst collapse areas in China, rendering a serve to potential karst collapse risks such as high speed railway, groundwater supply, gas pipeline and municipal constructions, which has achieved good results in the risk assessment of karst collapse, safe drawdown and collapse criterion.