压力分散型锚索差异张拉法在两河口水电站工程中的应用

Application of differentially tensioning method for pressure decentralized anchor-cable to construction of Lianghekou Hydropower Station

两河口水电站左右岸坝肩边坡开挖高度大,最大开挖高度达585 m,共布置有约2万束压力分散型预应力锚索进行边坡深层锚固支护。张拉作为预应力锚索施工的最重要工序,其施工质量及施工及时性直接影响边坡锚固稳定效果及边坡开挖进度。因压力分散型锚索的结构特性,常规张拉方法无法确保锚索张拉质量及张拉进度满足工程建设要求。本文主要介绍了差异张拉法施工工艺。

Because of the excavation heights of side-slopes of the abutments on both the right and left banks of Lianghekou Hydropower Station are higher with the maximum excavation height up to 585 m,about 20 000 bundles of pressure decentralized prestressed anchor-cables are arranged for the deep anchoring supporting of the slopes. As the tensioning is the most important working procedure for the construction of the pre-stressed anchor-cable,the effect of the slope anchoring stability and the excavation progress is directly impacted by its construction quality and promptness. Due to the structural characteristics of the anchor-cable,the conventional tensioning method cannot ensure the tensioning quality of the anchor-cable and the tensioning progress cannot meet the construction requirement as well,thus the construction technology of the differentially tensioning method is introduced herein.