LAUSR

This study addresses mechanical models of sinkhole formation and their criteria obtained via simulation test. Sinkholes are a common geohazard and are widely distributed throughout the world. Previous studies suggest that sinkhole formation is the result of complex interactions among geological conditions, with one or more factors triggering occurrence of sinkholes. We suggest that the existence of a void caused by soil loss is the premise of this issue. Therefore, we present soil loss is the mechanism of sinkhole formation in soils in this paper. Soil loss is caused by the interaction between groundwater and soils in nature. This interaction includes the groundwater condition and the characteristics of soils. In this study, we considered three types of groundwater conditions and two types of soils to discuss the mechanical model of sinkholes. There are three models of sinkhole formation in soils: the disintegration model in vadose zone, the seepage erosion model in unconfined aquifer, and the hydraulic fissures model in confined aquifer. A disintegration apparatus was designed to simulate the disintegration process and to obtain the criteria parameters of water content. Circular pipe flow equipment was designed to simulate the seepage erosion process to obtain the criteria parameter of groundwater velocity. The mechanical model of sinkholes in the confined aquifer was the hydraulic fissures model. The hydraulic equipment was designed to simulate the hydraulic fissure process to measure the criteria parameter of water pressure.