METHOD OF CONSTRUCTING PIPE ROOF

PROBLEM TO BE SOLVED: To improve workability in inserting pipes to a rock mass and construction precision in constructing a pipe roof.SOLUTION: Each of pipes 10 constituting a pipe roof 5 comprises plate-like members 13 on outer circumferential surfaces at both right and left sides of an upper portion thereof, respectively. When constructing the pipe roof 5, the plurality of pipes 10 are first inserted to a rock mass in such a manner that the plate-like members 13 of neighboring pipes 10 are confronted with each other with a predetermined clearance C1 interposed therebetween. A frozen soil layer 21 is next formed so as to cover above the predetermined clearance C1, in which the predetermined clearance C1 is such a clearance that the frozen soil layer 21 can be self-supported. A high-pressure water jet device is then used to remove sediment between the pipes 10 under the predetermined clearance C1, thereby forming a space 6a. Thereafter, concrete 34 is deposited within the space 6a partitioned by a mold frame 33 and the pipes 10 are connected with each other, thereby integrating the pipe roof 5.