The relationship between groundwater and ground collapse and land subsidence in Jinshazhou, Guangzhou City

Abstract: Soluble limestone and Quaternary loose soft soil are widely distributed in Jinshazhou. The fractures in limestone are rich and well connected with each other, which leads to a good connection of groundwater. All these factors provide objective geological environment conditions for karst ground collapse and land subsidence. Since April 2007, affected by tunnel groundwater pumping in high-speed rail construction, groundwater has fluctuated abnormally, which has resulted in ground subsidence and land collapse in Jinshazhou. The monitoring data and comparative analysis show that the karst ground subsidence and land collapse are controlled by groundwater level changes. When groundwater level fluctuates near the bedrock surface, the ground collapse occurs easily, and the land subsidence is related to groundwater level change positively. The relationship between land subsidence and groundwater level changes was also studied and, on such a basis, it is held that the area where groundwater has not yet returned to the normal level still has the hidden trouble of ground subsidence and land collapse.