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 publicprivate partnership project of the
Lianghu tunnel (Nanhu section), and adaptability tests of a lakephase silt solidification agent are conducted to investigate the
composition ratio, dosage, spraying, and stirring process of the solidification
agent, to provide launching conditions for ultralargediameter 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 onsite insitu
solidification tests demonstrate that the technology is feasible for lakephase 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.
