涟源市七甲村岩溶塌陷形成条件与机理分析

Analysis of karst collapse formation conditions and mechanisms in Qijia village, Lianyuan city, Guangxi

涟源市七甲村受斗笠山煤矿抽水影响,成为岩溶塌陷重灾区,已严重影响到当地居民生命财产安全。本文通过分析研究区资料,结合现场调查,认为岩土体条件、水文地质条件、岩溶发育程度、构造等因素是控制该区岩溶塌陷重要的地质背景条件。同时,基于塌陷坑调查资料,总结出研究区主要存在三种塌陷模式:(1)土洞塌陷;(2)岩洞塌陷;(3)落水洞塌陷。在三种塌陷模式中,地下水水位下降、岩溶管道填充物发生迁移及重新分配、土体自重及渗压效应起着重要作用,并将落水洞塌陷机理形象的概化为"沙漏模型"。最后,对研究区岩溶塌陷发展演化趋势进行了分析研究,认为受斗笠山煤矿继续往深部开采的影响,研究区会产生一些零星的新塌陷坑,同时一部分老塌陷坑会复活。

Qijia village has been turning into a serious karst collapse area that threatening the sefety of local people. The article summaries four geological background conditions of karst collapse, such as soil and rock condition, hydrogeological condition, karstification level and structure condition. Meanwhile it concludes three collapse modes based on field survey, such as soil cave collapse, rock cave collapse and sinkhole collapse. Effects of underground water level dropping, karst conduit filler removingor redistributing and soil self-weight gravity effect,seepage pressure effect are playing important roles in the three collapse modes. Then the sinkhole collapse mode is generalizing as a sand glass mode. Finally, the karst collapse developing and evolution trends have been studied and concluded that the research area can appear some scattered new karst collapses or some history collapse pits can appear secondary collapse, if the Doulishan coal mine is planning to mine deeper.