Modelling the evolution of overlying karst collapse based on the discrete element method

To study the evolutionary process of karst collapse caused by the fluctuation of groundwater level, a discrete element model of karst collapse is established by the high-performance discrete element software MatDEM. The results show that the scale of the soil cave formed by karst collapse grows with the fluctuation of the groundwater level. In the event of karst internal collapse, the range of water level fluctuation is positively correlated with the degree of karst cave development. And the soil spalling caused by the number of water level fluctuations has a stage characteristic. When karst ground collapse occurs, the larger the extent of water level fluctuations, the larger the size of the ground collapse pit. After a soil cave is formed, there is a significant horizontal stress concentration phenomenon at the foot of the soil cave.