杭州市环西湖覆盖型岩溶地面塌陷成因及预防

Genesis of Karst Collapse in the over-laying karst Area around West Lake in Hangzhou

覆盖型岩溶地面塌陷是西湖风景区潜在的工程地质问题之一。本文根据杭州市环西湖覆盖型岩溶地区多年水位观测资料和岩溶水开采强度资料,从时间上把岩溶水开采历史概化为3个阶段。不同开采阶段地下水位动态变化特征不同,因此岩溶地面塌陷表现为不同的塌陷形式,具有不同的成因机制。分析表明:研究区岩溶地面塌陷机制经历了扰动一压密、渗透一潜蚀、真空吸蚀3个演变阶段。本文根据研究区岩溶地面塌陷成因类型和现阶段岩溶水开采情况,提出岩溶地面塌陷预防措施。

Based on the grounderwater level data of last more than 40 years of the over-laying karst area around West Lake in Hangzhou, the history of exploiting karst water is classified into three periods. As the Variation of the volume of the discharge during different periods, over-laying-karst collapse has different characteristics. The analysis shows that the genetic evolution process of karst collapses experiences such three periods as： Disturbance-Consolidation Type, Infiltration- Underground-Erosion Type and Vacuum-Absorption Type. And now preventive measures for karst collapse should focus on avoiding Vacuum- Absorbing effects.