贵州省印江县岩口堰塞湖形成机制研究

Formation mechanism of Yankou barrier lake in Yinjiang,Guizhou

印江岩口堰塞湖是岩口滑坡地质灾害发生后形成的,通过对岩口堰塞湖的形成地质条件的分析,了解其形成影响因素以及形成机制认为:印江县岩口堰塞湖所处峡谷两岸碳酸盐岩形成高陡凌空的陡壁,由上硬下软的岩性组合与斜穿峡谷的斜向结构面(断层面)的不利组合,以及堰塞湖坝址原左岸坡脚砂石采场对坡脚的破坏是形成印江岩口滑坡而堵塞印江河形成堰塞湖的主要原因。堰塞湖的形成机制可以概括为:高陡斜坡坡体变形—滑坡启动沿断层面滑动—滑坡堆积体阻断印江河—河流水位快速上升—堰塞湖形成。

Yankou barrier lake in Yinjiang,Guizhou was formed after the occurrence of Yankou landslide.Through the analysis of the geological conditions of the formation of the barrier lake,it is found that its influencing factors are as follows:the high and steep walls formed by carbonate rocks on both sides of the narrow valley where the barrier lake is located,the unfavorable combination of hard upper rocks,soft lower rocks,and oblique structural planes(fault planes)that cross the narrow valley,and the destruction of the foot of the slope by the quarry on the original left bank of the barrier lake.The formation mechanism of the barrier lake can be summarized as follows:deformation of the high and steep slope leads to landslide along the fault plane,the landslide accumulation body then blocks Yinjiang River,which results in the rapid rise of water level and the formation of the barrier lake.