Abstract: Since the frequent occurrence of covered karst collapses induced by pile foundation construction in China, revealing the mechanism of covered karst collapse under impact is an important theoretical basis for proposing reasonable disaster prevention and monitoring plans. This article takes the Zhangjiawan sand leakage-type karst collapse induced by punching pile construction in the karst area of the binary structure stratum in Wuhan as an example. The physical model test and PFC-CFD coupled numerical simulation are used to explore the impact liquefaction-induced collapse mechanism of the sand leakage karst collapse, and thus, the corresponding insights for disaster prevention monitoring are obtained: (1) Pore water pressure monitoring devices should be installed at the bottom of the sand layer near the pile location and gradually constructed downwards with the punching pile. The peak value of excess pore water pressure triggered by impact will gradually increase. If the peak value is close to or equal to the effective stress of the overlying strata, an early warning should be initiated. If the pore water pressure cannot be restored to the original pore water pressure after further impact and a significant decrease occurs, it indicates that there is a karst cave or karst pipeline near this pile position and sand leakage has occurred. Therefore, pile construction should be stopped; (2) Settlement monitoring devices should be set up on the surface near the pile site. They may also detect a small amount of settlement before sand leakage occurs, and the settlement does not increase after each impact stops. This is due to the impact vibration compaction effect. When surface settlement accelerates, it indicates that sand leakage has occurred, and pile construction should be stopped.