Abstract: A method of lining a channel can be provided which includes the steps of: installing at a work site a roll having wound thereon a rigid or semirigid plastic pipe shaped initially in the form of an approximately round tube and deformed from the initial form to a flat tubular form, paying off the pipe as softened by heating from the roll installed at the work site toward an inlet of the channel to be lined, and folding the paid-off flat pipe in two to a U shape at a position between the roll and the channel inlet. The U-shaped pipe is hardened by forced cooling from outside immediately after the folding step while being restricted in shape, then inserted into the channel while being thus hardened and thereafter restored to the initial form by being inflated with heat and pressure applied from inside, whereby a lining of improved quality can be formed with an improved work efficiency.

Abstract: There is provided a double walled pipe having an inner pipe and an outer pipe which is movable relative to the inner pipe in a longitudinal direction of the inner pipe. Acting on only the outer pipe with a pipe jacking power makes it possible to bury the double walled pipe, without damaging the rear end of the inner pipe and also generating an internal stress on the inner pipe. Consequently, it is avoided such a situation that even in use pinholes, cracks, etc. occur on the inner pipe, and thus it is possible to expect an execution with higher reliability.

Abstract: There is provided a double walled pipe having an inner pipe and an outer pipe which is movable relative to the inner pipe in a longitudinal direction of the inner pipe. Acting on only the outer pipe with a pipe jacking power makes it possible to bury the double walled pipe, without damaging the rear end of the inner pipe and also generating an internal stress on the inner pipe. Consequently, it is avoided such a situation that even in use pinholes, cracks, etc. occur on the inner pipe, and thus it is possible to expect an execution with higher reliability.

Abstract: There is provided a double walled pipe having an inner pipe and an outer pipe which is movable relative to the inner pipe in a longitudinal direction of the inner pipe. Acting on only the outer pipe with a pipe jacking power makes it possible to bury the double walled pipe, without damaging the rear end of the inner pipe and also generating an internal stress on the inner pipe. Consequently, it is avoided such a situation that even in use pinholes, cracks, etc. occur on the inner pipe, and thus it is possible to expect an execution with higher reliability.

Abstract: A tunnel liner used for a shield tunneling method for a tunnel having a diameter of 1.5 to 7 m is fabricated by dividing a ring-shaped liner into a plurality of parts in the circumferential direction. The tunnel liner is required to be excellent in the dimensional accuracy with respect to the outer peripheral surface, to be tight, to be high in strength, and to be high in water tightness at the abutment between the adjacent liners. The tunnel liner is fabricated by a method of filling each arcuate enclosed hollow form with concrete, vibro-compacting concrete, molding the end surfaces of the tunnel liner, mounting the forms within a centrifugal molding drum, and tightly molding the outer peripheral surface of the forms by applying of a centrifugal force. According to this fabrication method, it is possible to effectively fabricate an excellent tunnel liner at a low cost.

Abstract: A conduit comprised of double-wall pipes A is laid in the ground by the pipe-jacking method. Each of double-wall pipes A comprises inner pipe 1 and outer pipe 2 and is provided with sheath pipe 4 between inner pipe 1 and outer pipe 2 and with check valve 7. Winch 11 is mounted in tunneling machine 6. Wire 12 wound on winch 11 is inserted into sheath pipe 4 and the forward end of wire 12 is sent to start vertical shaft C through sheath pipe 4, and connected with cleaning member 24, injecting member F, and supply pipe 14. Cleaning member 21, injecting member F, and supply pipe 14 are moved in sheath pipes 4 by driving winch 7. When injecting member F is opposed to check valve 7, packing means 19, 20 are inflated to be brought into contact with the inside of sheath pipe 4 by which injecting member F is fixed to sheath pipe 4.

Abstract: When a shield tunneling machine is deviated from the scheduled line while being propelled, the deviation of the shield tunneling machine from the scheduled line is detected and according to the data obtained on the deviation of the shield tunneling machine from the scheduled line, the propelling direction of the shield tunneling machine is automatically controlled.

Abstract: When laying a conduit comprised of double-wall pipes A, each of which comprises inner pipe 1 and outer pipe 2, the smooth propulsion of double-wall pipes is possible by injecting lubricant into a space between the outside of double-wall pipes and the ground on a scheduled line along which conduit B to be laid is divided into section, each having a given length based upon the distance over which the effect of the lubricant can be maintained. Lubricant is injected from the double-wall pipes which is to be positioned at the heads in the respective sections 1 to n of supply pipes 3 which are provided between inner pipe 1 and outer pipe 2 of double-wall pipe A. Supply pipes of double-wall pipe A which has been propelled are connected with supply pipes of a new double-wall pipe, wherein the number of supply pipes connected with each other is determined for the respective sections. Lubricant is supplied from the upstream side and from the downstream side of the propelling direction to double-wall pipes.

Abstract: An air vent device for a fuel tank on a vehicle, having paired first and second air vent pipes joined to the portions of an upper section of a fuel tank which are spaced from each other in the lateral direction of said vehicle, and a main air vent pipe connected to said paired air vent pipes to communicate the same with the atmospheric air. A connecting point of said three air vent pipes is positioned below at least one of left and right maximum-angled surfaces, which are inclined with respect to the lateral axis of said fuel tank, of a fuel contained therein. A normally-opened float valve adapted to be closed when the fuel reaches the same is provided in said first or second air vent pipe, which is on the side of said connecting point.

Abstract: A system for repairing joints in pipes laid underground, such as gas pipes, in their buried state, from their inside, to ensure their sealing.The system, in the process of pushing the resin used for repairing along the inside of the pipes by the pig, is to fill and seal the sealing material with the resin through gaps in numerous pipe joints inside of the pipes. In order to guarantee insertion of resin into gaps in the pipe joints (sealing material) whether or not the pipe joint has developed a leak, the system comprises a substitution pig, and a means whereby the pig pushes the resin placed ahead of it along the pipe, and further, a means whereby the filling amount of the resin does not change even if the amount of resin present in front of the pig differs between the early and later stages of the repairing operation, gaps in the pipe joints will be uniformly filled.