An overview on karst collapse mechanism in China

As of 2022, more than 3,800 karst collapses were reported in China. Because of concealment and suddenness, these collapses have posed significant impacts on people’s daily life, infrastructure construction, and safe operation of thousands of miles of high-speed railway in karst areas. Summary of the last 90 years’ studies on karst collapses resulted in a diverse collapse mechanism including suffosion, vacuum negative pressure, groundwater gas pressure, hydrofracturing, and vibration. Most of the mechanisms are interpretative and lack support for scientifically defensible data. Recent bench-scale testing led to a new finding in which collapses occurred with high frequency fluctuation of water level. This finding has significant implications in karst collapse prevention, monitoring, and mitigation. Several hypotheses including pressure pulsation, cavitation, and resonance are proposed, however concerted studies are necessary to understand and quantify the dynamic processes.