METHOD FOR INSTALLING CONDUIT PENETRATING LEVEE BODY BY NON-OPEN-CUT METHOD

摘要

PROBLEM TO BE SOLVED: To efficiently install a conduit penetrating a levee body by a non-open-cut method and to provide a complete water seal property. SOLUTION: Cement slurry S blended with a hardening accelerator is injected from an injection nozzle 21 guided from the top end 11 of the levee body 1 and substituted to form an impervious wall main body 3 having the desired height and width. A propulsion pipe 5 fitted with a drilling machine 7 with the diameter slightly larger than the pipe diameter at the head is thrust into the levee body 1 horizontally continuously from a vertical shaft 4. When the propulsion pipe 5 reaches a planned pipe crossing the impervious wall main body 3, a plurality of circular impervious bags 61 each having a barrel section impermeable to a grout material G and moisture and a sewn section permeable to only the air with a fixed pressure or above on the whole periphery are expandably folded and stored. An impervious propulsion pipe 6 opened with a grout injection port 62 is connected between the circular impervious bags 61, and normal propulsion is continued to form the conduit penetrating the levee body 1. The grout material G is pressed into the circular impervious bags 61, the air compressed in the bags 61 as the filling progresses is discharged from the sewn sections and expanded to form circular gaps C into closed sealed spaces. The grout material G is pressed into the sealed spaces from the grout injection port 62, the gaps C are filled regardless of size and shape, and the conduit having an excellent water stop property is installed by the non-open-cut method.