Analysis of the distribution pattern and catastrophic mechanism of ground collapse disasters in Shenzhen

【Objective】In recent years, Shenzhen has experienced frequent ground collapse events. This study aims to clarify the spatial distribution patterns and catastrophic mechanisms of ground collapse disasters in the city, thereby providing theoretical support for effective prevention mitigation. 【Methods】Ground collapse incidents from 2015 to 2024 were examined using mathematical statistics and GIS-based spatial analysis to reveal the spatio-temporal evolution patterns and spatial associations of key causative factors. In additiona, physical model experiments were conducted to investigate the catastrophic mechanism of ground collapse induced by the coupled effects of seepage erosion and soil deformation triggered by pipeline leakage. 【Results】The results show that the occurrence of ground collapse is positively correlated with rainfall variations and exhibit a single-peak fluctuation pattern within an annual cycle. Spatially, the disasters demonstrate a pronounced east-west differentiation, and their occurrence probability is positively associated with road density and subway network concentration. The disaster process of hourglass type ground collapse in unpressurized gravity flow pipelines primarily consists of three stages: initial, stable, and seepage. The expansion of subsurface voids caused by soil erosion and deformation aligns with the changes in sand loss. In contract, sinking-type collapses induced by pressurized pipelines in clay layers do not present distinct evolutionary stages. 【Conclusion】This study reveals the spatiotemporal evolution patterns and key disaster mechanisms of ground collapse disasters in Shenzhen. The findings provide a scientific basis for urban ground collapse risk identification and for developing targeted prevention and control strategies.