预应力锚索施工技术在西藏林芝老虎嘴水电站高边坡加固中的应用

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

西藏林芝老虎嘴水电站在进行导流洞、泄洪洞出口洞脸边坡开挖施工过程中,由于边坡地质条件差、岩层破碎,在边坡下部形成了较大范围的塑性区,边坡变形加大,导致开挖边坡及顶部自然边坡相继产生了一系列的拉裂缝且扩张迅速,导致多次发生较大规模塌方。为确保边坡稳定和施工安全,业主、监理、设计及施工单位四方针对边坡加固制定出切实可行的治理措施,其中采用了大量的预应力锚索对边坡岩体进行了预应力锚固,效果明显。

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.