深開挖工區湧水災變之緊急搶救與止水補強實例（第二部份：止水補強灌漿之設計與施工）

A Case History on Stoppage of Water Ingress from a Deep Excavation Site Part 2: Design and Construction of Seal-Off Grouting

胡邵敏(S. M. Woo) ； 歐來成(L. C. Ou)

《地工技術》 88期 (2001/12) Pp. 105-116

https://doi.org/10.30140/SG.200112.0007

摘要

本文繼續記述前文第一部份湧水事件在採取緊急措施後，工區崩坍危機解除，後續灌漿工作之設計與施工。灌漿是為封堵湧水孔及改良已被淘砂擾動之地層而作。文內詳述此次灌漿規畫考量、分區原則、孔位佈置、施灌深度、材料配比、施灌壓力及施灌之順序過程。同時亦述及在施灌過程中，為克服中間柱及水平支撐上浮問題而採取之應變措施。灌漿區最後經取樣試驗及降水測試後證明效果良好。結論中強調此次灌漿所獲之寶貴經驗，並由此次湧水事件所得之教訓，建議工程界日後在進行深開挖工程時，應更重視大地工程師之角色。

關鍵字

豎管式灌漿工法 ； 馬歇管灌漿工法 ； 低壓灌漿 ； 水泥皂土漿液 ； 阻隔牆 ； LW灌漿法 ； 地層上浮 ； 地層改良 ； 降水測試

並列摘要

This Article is the Part 2 of the previous Paper on the water ingress event occurred at the CN252 site. The site which was temporarily stable after the emergency measures under-taken, still required complete sealing off of all water paths, drilled holes and soil strengthening below the excavation grade prior to work resume. Described in details herein, are the design considerations and grouting processes used; it covers the objectives and zoning of grouting, grout holes layout, grout depth of each zone, mixture of grouts, grouting pressure specified and sequence of work. To overcome the upheaval of king posts and struts due to injection of grout into the confined area, many modifications on grouting processes have been applied. Finally, laboratory tests results of drilled samples and still water tests in the grouted area proved that the grouting work is effective. The concluding remarks emphasize the invaluable experience achieved from the grouting work and the lessons learned from this event. The necessity of placing more weight onto the role of geotechnical engineers in deep excavation projects are also stressed.

並列關鍵字

grouting with standpipes ； tube-a'-manchette grouting technique ； low pressure grouting ； cement-bentonite mixture ； cut-off wall ； LW (labile waserglas) grout method ； ground upheaval ； soil improvement ； still water test