摘要:
泰莱盆地位于山东省中部,截止2013年底,盆地内共发生有记录岩溶塌陷97处,161点次,严重威胁人民生命财产安全。文章在总结前人研究基础上,结合最新调查、监测成果,研究了泰莱盆地岩溶塌陷的分布特征、地质结构模式及其形成机理。结果表明:盆地内岩溶塌陷点多集中分布于岩溶地下水降落漏斗及其影响范围内;塌陷点分布受构造控制明显;塌陷区第四系厚度一般小于30 m,下伏基岩主要为奥陶纪灰岩;80%以上的塌陷集中发生于汛期。根据岩溶塌陷点土层结构、地下水动力条件的不同,建立了3种岩溶塌陷的基本地质模式:单层、双层和多层结构土层岩溶塌陷,其中单层结构土层岩溶塌陷的形成历经“真空吸蚀-崩解剥落-塌陷”3个阶段;双层土层结构岩溶塌陷形成演化过程可概括为“渗透变形-崩解垮塌-塌陷”或“真空吸蚀-渗透变形-塌陷”3个阶段;多层结构土层岩溶塌陷历经“真空吸蚀-渗透变形-崩解垮塌-塌陷”4个阶段。
关键词:
-
泰莱盆地
/
-
岩溶塌陷
/
-
地质模式
/
-
机理
Abstract:
The Tailai basin is located in the east of Shandong Province.By the end of 2013,the history re-cords karst collapses up to 1 61 in number,which occurred at 97 locations.Based on previous studies,the up-dated survey and monitoring results,this work makes a research on karst styles,characters and formation mechanism of karst collapses of the Tailai basin.The results show that these karst collapses are concentrated in the groundwater drawdown funnels and affected areas.Their distribution is obviously controlled by geo-logical structures.The thickness of Quaternary System above the subsidence areas is generally less than 30 meters,with underlying bedrock of Ordovician limeston.More than 80% of the karst collapses occur in flood seasons.Three geological models of karst collapses are established on the basis of stratum structures and groundwater dynamic conditions at collapse sites:(1)karst collapse in single-layer structure without aquifer;(2)karst collapse in two-layer structure;(3)karst collapse in multiple-layer structure with aquifers.The process of the first karst collapse is “vacuum suction erosion-disintegrating peel-collapse”.The process of the second karst collapse is “seepage deformation-disintegration-collapse”or “vacuum suction erosion-seepage de-formation-collapse”.And the process of the last one is “vacuum suction erosion-seepage deformation-disinte-gration-collapse”.This paper provides scientific basis for risk prediction and geologic hazard control in karst collapse areas.
下载: