三峡左厂房1—5^#坝段基础加固预应力锚索施工

三峡左岸厂房１－６＃坝段轴线长２２９．８ｍ，基础开挖后形成近７０ｍ的高边坡，由于断裂组合形成倾向下游的不利滑动面。加固处理主要采用３０００ｋＮ级预应力锚索，共２１８束，长３０－５５ｍ，钻孔孔径１６５，总进尺８４４５．６ｍ，锚索施工一钢管槽开挖交叉进行，施工后经监测，锚索实际伸长率与理论值吻合罗好，锁定锚固损失在１－３％，满足设计要求。

Strengthening Penstocks Foundation with Prestressed Cables

The blocks No. 1 ~ 6 of the powerhouse at the left side of the spillwayhas an axial length of 229. 8 m. After excavation, the foundation had 70 m high slopewith adverse slide plane toward the downstream. The high slopes were primarily stengthened with 218 strands, 30 ~ 55 m long and 3 Ooo kN prestessed cables. The hole diameter was 165 mm and the total drill length of 8445. 6 m. The anchorage cables wereinstalled alternately with the excavation of the penstock trenches. The monitoring datahave shown that the construction quality meets the design specificaitons, the real elongation ratio of the cables falling within the range of the design values, and the loss ofanchoring force being within 1 % ~ 3 %.