【作者】 余念梓； 倪至寬； 游澄發； 王薇薇； 陳步彥；

【Author】 Yu,Nian-Tz 1,Ni,Chin-Kuan 2,Yu,Cheng-Fa 1,Wang,Wei-Wei 3,Chen,Pu-Yen 3 1 Central District Project Office Department of Rapid Transit Systems,TCG,Taipei 2 Taipei University of Technology,Taipei 3 Raito Engineering Company,Taipei

【机构】 臺北市政府捷運工程局中區工程處； 臺北科技大學土木與防災研究所； 利德工程股份有限公司；

【摘要】 JSG高壓噴射灌漿工法,在壓力水層進行鑽孔與灌漿作業時,或者在地下室內進行鑽孔與灌漿作業時,因為地下水位高於鑽孔與灌漿作業場地,為了避免在進行鑽孔與裝設灌漿管作業階段,可能造成湧水、湧砂、路面掏空或建築物傾斜的意外事件,在進行鑽孔與裝設灌漿管作業前,先設置點井,然後裝設抽水井,以降低附近地盤的地下水位,待地下水位降至設計高程時,在灌漿工作面裝設止水器組,然後才可進行鑽孔與灌漿作業。在地下室內進行灌漿作業時,利用筏基水箱來量測每公尺改良樁的排泥漿量,不但可用來管制湧水與湧砂的潛在問題,而且搭配量測排泥漿的比重,以評估改良樁的直徑品質。其次,灌漿的順序也能影響改良樁的單位重與強度。所以,在地下水位下進行之JSG高壓噴射灌漿,如果採用本研究建議的品管手法,將可有效的進行承商的第一級品管,可提高第二級品管的驗收率。更多还原

【Abstract】 In this study,jet grouting is conducted in the basement and the groundwater level is above the platform of drilling and grouting operations,pumping wells are installed to lower the groundwater level below operation platform before drilling and grouting in order to avoid the risk of water ingress,sand boiling,ground settlement and building tilting.During the get grouting in the basement,several quality control means by measuring the volumes and unit weights of spoil returns twice for each column are taken.The diameter of jet grout column is back calculated from the mean values of volumes and unit weights of spoil return.The control chart of the volume ratio between spoil return and grout can successfully predict the event of water ingress or sand boiling through the holes on the diaphragm wall and mat foundation.Since grouting sequence can also affect the spoil unit weight,optimum grouting sequence is important to be considered.Base on the results from this study,sand boiling can be effectively detected by monitoring the variation of spoil volumes.It is recommended that the measurement of volume and unit weight of spoil return should be included in the quality control measures,especially when jet grouting platform is below the groundwater table.更多还原