三峡船闸高边坡预应力锚固施工技术

Prestressed anchoring technology for the high slope of Three-gorge Lock

三峡船闸是目前世界上规模最大、水头最高、结构最复杂的船闸,人工开挖边坡最大高度170m,下部直立坡最大高度67 8m,地质条件相对较复杂,直立岩壁上有大小1000多个不稳定块体出露。锚固工程是保证施工安全和结构安全的主要措施,预应力锚固一般为水平孔、多为3000kN级,孔深索长30～57m,数量多、技术要求高,施工作业条件差,施工干扰多。施工中针对系列技术难题,进行了试验攻关。文章介绍了长江三峡船闸锚固工程的设计情况和施工技术难题。重点介绍了钻机的改造,水平锚固孔防斜保直钻进工艺、锚固孔测斜技术,水平孔止浆措施及编索、下索等方面的各项技术措施和施工干扰的协调处理。通过锚索测力计、岩体变形等观测资料表明工程岩体及边坡稳定,一整套预应力锚固技术工艺创新,达到了预期效果,经验可供参考。

The Three-Gorge Lock is the ship lock with the largest scale,highest water head,most complicated structure;the maximum height of the manually-excavated slope is 170m,and the maximum height of the lower erect slope is 67.8m;the geological conditions are relatively complicated;there are more than 1000 unstable outcrop blocks on the vertical cliff.The anchoring project is the main measure to ensure the construction and structural safety.The prestressed anchor often adopts the horizontal borehole and is of 3000kN grade,with the length of 30m to 57m;the construction is faced with such problems as large amounts,high technical requirements,poor construction conditions,many interferences.Aiming at a series of technical problems,many experiments have been done to tackle these problems.This paper introduces the design and constructing technical problems in the anchoring project of Changjiang Three Gorge Lock,and mainly discusses the transformation of the drilling machine,anti-inclination drilling echnology of horizontal anchorage hole,inclinometry technology of horizontal anchorage hole,grout-sealing measures for the horizontal borehole,technical measures for the cable making and cable driving,and the coordination of construction interferences.The observation data from the anchor cable dynamometer,the deformation observation,etc.indicate that the engineering rock mass and slope are very stable and the whole set of prestressed anchoring technologies have reach the goals,therefore,such experiences can be a reference for other projects.