清江茅坪滑坡形成演化研究

STUDY ON GENERATION AND EVOLUTION OF MAOPING LANDSLIDE ON QINGJIANG RIVER

茅坪滑坡是清江隔河岩库区当前变形最严重的大型滑坡,其形成演化研究对于茅坪滑坡发展趋势预测和防治有重要意义。首先,论述清江茅坪滑坡的研究现状,根据清江河谷岸坡发育演化的的地质历史和环境,从河谷演化的角度推定茅坪滑坡发生的时间上限为晚更新世。其次,研究茅坪滑坡的滑带和滑体结构特征,使用工程地质力学分析方法研究茅坪滑坡滑带和滑体物质的来源和成因。最后,讨论茅坪滑坡的形成演化过程与机制。

The Maoping landslide is located on the right bank of the Qingjiang River, Geheyan Reservoir Area in Hubei Province of China. It is an ancient landslide with a volume of 2.35× 10^7 m^3. After Geheyan Reservoir impoundment in April 1993, the Maoping landslide becomes the most dangerous landslide in Geheyan Reservoir with a maximum displacement of 2 100 mm until now. According to the development history and geological environment of the Qingjiang River valley and bank, the upper time limit of the Maoping landslide occurrence is estimated at Epipleistocene by valley evolution analysis. The component and structure characters of sliding surface and sliding mass are studied. By using the engineering geomechanics analysis method, the origin and cause of sliding surface and sliding mass are studied. The sliding surface comes from primary stratum of D3h and generates after weathering. The sliding mass comes from rock falling mass of slope back side. The process of the Maoping landslide formation and evolution is discussed. On the basis of above analysis, the generation and evolution of the Maoping land slide are deduced. The activity of the Maoping landslide has intimate relation with the rock falling of slope back side through landslide evolution process analysis. Moreover, the displacement monitoring shows that the intensive rainfall has important contribution to landslide. Therefore, attention to intensive rainfall and rock fall monitoring is advised.