16m级盾构始发筑岛围堰湖相淤泥原位固化试验研究  

Study on In-Situ Solidification of Lake-Phase Silt in an Island Cofferdam Construction for Launching a 16-m Shield

作　　者：宋相帅 何源[1,3] 韩晓明 许超[1,2] SONG Xiangshuai;HE Yuan;HAN Xiaoming;XU Chao(CCCC Second Harbour Engineering Company Ltd.,Wuhan 430040,Hubei,China;Research and Development Center of Transport Industry of Intelligent Manufacturing Technologies of Transport Infrastructure,Wuhan 430040,Hubei,China;CCCC(Nanjing)Construction Co.,Ltd.,Nanjing 211899,Jiangsu,China)

机构地区：[1]中交第二航务工程局有限公司,湖北武汉430040 [2]交通运输行业交通基础设施智能制造技术研发中心,湖北武汉430040 [3]中交(南京)建设有限公司,江苏南京211899

出　　处：《隧道建设（中英文）》2024年第2期288-295,共8页Tunnel Construction

基　　金：国家自然科学基金面上项目(52379114);中交集团重大科技研发项目(JSKF-20210225-002)。

摘　　要：为满足城市内湖筑岛围堰内超大直径盾构始发作业需求,依托武汉两湖隧道(南湖段)PPP项目3标围堰淤泥固化工程,开展湖相淤泥固化剂适配性试验,探究固化剂成分配比、固化剂质量分数、喷搅工艺及浮淤对固化效果的影响;通过轻型动力触探试验、固化翻浆层厚度测试明晰淤泥固化效果,以获取最佳固化剂质量分数及固化工艺。试验研究表明:1)通过固化剂适配性试验、现场原位固化试验可知,湖相淤泥采用原位固化工艺是可行的,能满足施工承载力等指标要求;2)针对南湖湖相淤泥,考虑固化土强度及均匀性,选取m_(水泥)∶m_(工业废渣)=6∶4、固化外加剂质量分数为1‰及固化剂质量分数为10.5%的固化剂处理效果较好;3)采用“4搅4喷”固化工艺,可以减少翻浆浪费,且可以均匀加固淤泥地层。通过评估不同工况下筑岛围堰内试验田淤泥固化效果,提出了最佳固化剂质量分数及固化工艺,解决了淤泥固化强度不足、均匀性不良等质量问题。A case study is conducted on a sludge solidification project of Bid 3 of a public-private partnership project of the Lianghu tunnel(Nanhu section),and adaptability tests of a lake-phase silt solidification agent are conducted to investigate the composition ratio,dosage,spraying,and stirring process of the solidification agent,to provide launching conditions for ultra-large-diameter shields in urban lake island building cofferdams.Furthermore,the solidification effect of sludge is clarified through light dynamic penetration tests and thickness tests of the solidification slurry layer to obtain the optimal amount of curing agent and process.The experimental research results suggest the following:(1)The curing agent adaptation and on-site in-situ solidification tests demonstrate that the technology is feasible for lake-phase sludge and meets the requirements of construction bearing capacity and other indicators.(2)A solidified agent with a mass ratio between cement and industrial waste of 6∶4,solidified admixture dosage of 1‰,and geopolymer solidified dosage of 10.5%exhibits a good treatment effect,considering the strength and uniformity of the solidified soil of the sludge in the Nanhu section.(3)A solidification process with four stirring and spraying cycles is more conducive to ensuring the demand for a unit volume of curing agent dosage,reducing slurry waste,and uniformly strengthening the silt layer.A reasonable amount and solidification process of silt solidification are proposed,which successfully improves the solidification strength uniformity of sludge by evaluating the solidification effect of silt in the experimental field of building an island cofferdam under different working conditions.

关 键 词：超大直径盾构 筑岛围堰 湖相淤泥 淤泥原位固化试验 轻型动力触探试验 翻浆层厚度 

分 类 号：U45[建筑科学—桥梁与隧道工程]