广州市荔湾区大坦沙岩溶地面塌陷成因及其稳定性评价

广州市荔湾区大坦沙是广州地区岩溶地面塌陷主要发生地区之一,2007-11-07-2008-01-29共发生7起岩溶地面塌陷,造成多间房屋倒塌和开裂,经济损失巨大.通过参与现场地质调查,之后收集、整理该地区地下水的动态监测资料,结合地面塌陷发育的基本特征,从区域地质环境条件分析其地面塌陷的形成原因,采用定性、半定量的评价方法,构建岩溶地面塌陷稳定性判别因子的量化指标体系,对其地面塌陷的稳定性进行综合预测.结果认为:(1)大坦沙地区岩溶地面塌陷具有一因多效现象,地下水位下降是引发该时段系列塌陷的主导因素,次要

Karst Ground Subsidence and Stability Evaluation for Datansha, Guangzhou

Datansha at Liwan District is one of the areas in Guangzhou where karst ground subsidence occurs frequently.From November 7,2007 to January 29,2008,seven subsidence events happened,causing many houses’ collapse or crack,and huge economic losses.In this paper the data of the geological survey and groundwater dynamic monitoring in the area are analyzed.The authors consider that those events were induced by a lot of factors,in which the dominant was the fall of the ground water level.Qualitative and semi-quantitative methods are used to evaluate the factors that affect the geological environment condition of the ground subsidence.From those factors,karst development level,ground water level,dynamic change of the ground water depth,ground water yield,soil structure and geomorphological characteristics are selected to be the first-grade discrimination factors,each of which is divided into 4 second-grade factors,so as to form a quantitative index system to evaluate the stability of the area liable to karst ground subsidence.The result of the comprehensive evaluation with the index system shows that Datansha is a less stable area in karst ground subsidence.