Application of Prestressed Anchor Construction Technique in High Slope Stabilization at Laohuzui Hydropower Station in Lingzhi of Tibet

During slope excavation construction at diversion tunnel and spillway tunnel outlets at Laohuzui hydropower station in Lingzhi of Tibet,a large plastic zone was formed in the lower part of the slope due to poor geological conditions and fractured rock mass with increased slope deformation,resulting in sets of tensile cracks occurring in excavated slope and natural slope at the top.These cracks extended rapidly,causing large scale collapses in many times.In order to ensure slope stability and construction safety,practical treatment measures for slope stabilization were made by four parties concerned,including Owner,Supervisor,Design and Construction units.Large quantities of prestressed anchors were used in slope rock mass for slope stabilization with good results.At present,the slope,diversion tunnel and spillway tunnel are in stable conditions and excavation in dam and powerhouse areas are being carried out on time.