震裂山体滑坡一溃决型泥石流特征及防治措施研究

Research on Shattered Landslide-Debris Flow Characteristics of Break and Prevention Measures

"5.12"大地震后形成较多震裂山体,震裂山体在暴雨、余震作用下一旦失稳,将会形成高势能滑坡,堵塞下部沟道,形成堰塞湖,在动静水压及掏蚀作用下导致堰塞湖的溃决,形成破坏力极强的溃决型泥石流。四川安县甘沟泥石流就是典型的溃决型泥石流,2009年8月24日,由于强降雨作用,甘沟支沟牛颈沟滑坡高速下滑,形成堰塞湖最终溃坝,暴发了溃决型泥石流,为震区典型的滑坡-泥石流地质灾害链。由于牛颈沟还残余大量物源,在暴雨情况下再次暴发溃决型泥石流的可能性很大,因此提出以下应对措施:护排为主,结合低坝消能;及时清淤,恢复植被;加强监测,及时警报。

A large of shattered mountain had been formated after the ＇5·12＇ earthquake.The shattered mountain in the fallrain,once the instability under the aftershocks will be the formation of high potential landslides,blocking the lower part of the channel,the formation of barrier lake,with the static pressure and big erosion caused the barrier lake to break,the formation of highly destructive break debris flow.The Gan gully debris is a typical break debris flow.In Niujing gully,landslide occurred and barrier lake formed in the earthquake.In the impact from rainfall,the part residual body of Niujing gully has been glided,and caused the dam-break.Finally,triggered the outbreak of break debris flow on August 24,2009.It was a typical geological hazard chains of landslide-debris flow.It has much possibility to break out debris flow again in case of heavy rain because of a large number of sources in the Niujing gully.So the following measures were proposed： protecting and draining are chief measures,and combining dam,timely dredging,restoration of vegetation,strengthening monitoring and warning in time.