METHOD FOR REUSING DISCHARGED SOIL IN HIGH DENSITY SLURRY SHIELD WORK

摘要

PROBLEM TO BE SOLVED: To provide a reuse method of discharged soil in the high density shield work in which faborable results can be obtained in both processes of excavation and pumping force- feed and the hardening process can be favorably carried out and by which the discharged soil of the high density slurry shield work can be reused as hardened soil having a reusable unconfined compresive strength. SOLUTION: In the high density slurry shield work in which a cutting face is excavated while acting the pressure of an additive for excavation on the cutting face, the additive for excavation composed of a water-adsorbing resin and a water-soluble resin is dissolved in water to swell and it is injected with a pressurized condition into a cutter chamber for excavation. The discharged soil in the excavation process is force-fed to the outside of the tunnel by a pump without addition of other chemicals. The discharged soil is treated with an inorganic hardener comprising of an organic hardener and a gypsum-based compound to reuse it as recyclable soil. A cross-lnking substance of acrylic acid (salt)-vinyl alcohol copolymer and/or a crosslinking substance of polyacrylic aid (salt) are used as the water- absorbing resin and Semi-synthetic water-soluble resin and/or synthetic water-soluble resin are used as the water-soluble resin and further, substances containing water-absorbing resin powder, natural water-soluble resin powder, and organic powder are used as the organic hardener respectively.