Resurgent characteristics of Zhama Landslide and river blocking risk analysis in the upper reaches of Jinsha River
With the continuous intensification of human engineering activities and the frequent occurrence of ex-treme weather,the problem of ancient landslide resurrection and river blocking is becoming more and more promi-nent,which seriously threatens the safety of mountain towns.Taking the Zhama ancient landslide on the right bank of Baqu River in the upper reaches of Jinsha River as an example,using UAV aerial survey,field investigation and numerical simulation analysis,the characteristics of the resurrection of ancient landslide were identified,the de-formation and failure range and instability probability of landslide under different rainfall conditions in different re-currence periods were analyzed,and the process of landslide movement,accumulation range and river blocking risk under different working conditions were simulated and studied.The results show that:(1)The local reactiva-tion of the Zhama landslide front is mainly characterized by clear surface deformation signs and progressive tractive failure.The volume of the front reactivation area H1 is about 185×104 m3,with the possibility of further destabili-zing sliding.(2)The front edge H,of the landslide is stable in its natural state,unstable under monthly extreme rainfall conditions that occur once every 20 years,with a probability of instability of 87.95％,under monthly ex-treme rainfall conditions that occur once every 50 years and 100 years,the front edge H1 and rear H2 are overall un-stable,with probabilities of instability of 58.75％and 68.60％.(3)After the front H,is unstable,and the rear H2 and H,are continuously unstable,the maximum velocity at the groove is 9 m/s and 11 m/s,respectively,and the slip distance is as far as 480 m.A barrier dam with a height of 42～48 m is formed in Baquu channel.(4)The backwater formed after the blockage of Baqu may inundate the G318 National Road,residential buildings and sta-tion and other infrastructure in Deda Township upstream of the landslide,covering an area of 0.81～1.02 km2.The dammed lake may overflow within 7 days,which requires high attention.
ancient landslideresurrection characteristicsextreme rainfallinstability probabilityriver blocking hazard
万方数据
维普
