| 摘要 |
PROBLEM TO BE SOLVED: To prevent troubles resulting from reaction of unreacted cement and aqueous slurry, in a shielding operation, by mixing an inhibitor against the solidifying reaction of cement in the slurry for stabilizing the cutting face, when excavating a soil improvement part by a slurry pressure-shielding method. SOLUTION: When cement slurry is injected in the ground at a specified range of concentration by the use of a column jet grout method to construct an improved ground and excavate the ground, gluconic acid is mixed in aqueous mud slurry by a specified range of weight percent. In this way, since the excavated soil in the improved ground is not solidified for a specified time interval in accordance with the added volume, the excavated soil can be discharged without troubles in the stream from the cutting face to the discharge point. The slurry with gluconic acid is adjusted in an extent that the purpose of the safe cutting face is achieved while taking into consideration the concentration of the unreacted cement in the improved ground and the inhibitor against the solidifying reaction of cement in the slurry. |
