Experimental and numerical study on explosion cratering and coupled ground shock in clay

The ground shock induced by underground explosion poses a serious threat to underground projects. Currently, a unified calculation method for ground shock effects coupled with cratering effect has not been established owing to limited test data. This study adopted the ground shock effective crater volume as the energy source of the underground explosion. An equivalent calculation method for ground shock effects in cratering explosion was proposed. A theoretical conversion method between the three the coupling coefficient of equivalent yield, the coupling coefficient of ground shock energy, and the coupling coefficient of ground shock parameter has been developed. Through explosion simulation tests with varying burial depths in clay media, the changing patterns between the size of visible craters, ground shock effective craters and coupled ground shock energy were revealed. A numerical calculation model was established to investigate the relationship between the ground shock effective crater size and energy coupling of the ground shock in detail. By comparing and analyzing the theoretical, experimental, and numerical simulation results, the relationship between the explosive coupling coefficient of ground shock energy and the scaled depth of burial (SDOB) of clay was presented. The research results indicated that there was a linear relationship between the underground explosion compression crater volume (or fragmentation zone volume) and the ground shock energy. The test and numerical simulation analysis results validated the correctness of the coupling coefficient of ground shock conversion calculation method. The obtained clay coupling coefficient of equivalent yield function expression can accurately and rapidly predict the ground shock effect of underground explosions, providing a calculation basis for the anti-explosion design of underground engineering under clay geological conditions.