EVALUATION ON CAUSES AND CONTROL EFFICIENCY OF RAINFALL-INDUCED LANDSLIDE AT BEE FARM IN ILI

he landslide at a bee farm in Ili was affected by natural rainfall and human engineering activities cutting the slope,which posed a serious threat to the lower residents and various facilities. At present,the prevention and control measures on the landslide has been constructed. But its disaster-causing mechanism is still unclear. The effect of prevention and control measures is not well evaluated. In view of this,this paper takes the bee farm landslide as an object,and uses various means such as field geological survey,UAV aerial photography,D-InSAR technology,indoor test and theoretical analysis. It investigates the cause mechanism and destabilization mode of the rainfall-type landslide at the bee farm. The effectiveness of the prevention and control measures is evaluated. The results show that the loss of the important slide-stopping section of the slope due to engineering activities and the development of surface joints,fissures,wormholes and rootholes in the chalk soil provide advantageous pathways for rainfall infiltration. The abundant natural rainfall promotes the generation of internal sliding surface by infiltrating the surface soil and raising the groundwater level. The landslide is a typical rainfall-type landslide with a traction-type progressive damage mode of instability. Through the monitoring and analysis of D-InSAR technology,the change range of surface deformation of this landslide are 36~44cm ·a^-1 and -4~4cm ·a^-1 respectively before and after the prevention and control measures. The surface deformation was obviously reduced. Meanwhile,combined with the analysis of field investigation,it is concluded that the prevention and control effect of the landslide at the bee farm is obvious. The research results of this paper can enrich the theoretical basis of rainfall landslide research in Ili,Xinjiang,and also provide reference for landslide disaster control of the same type in the region.