To ensure prevention of leakage of fluid and to improve earthquake resistance by a method wherein a fiber material is formed in a cylindrical state that the fiber material is changeable into an expansion state and a contraction state.
A cylindrical body 2 for reinforcing a line is formed such that twelve organic fibers 22 of a material NBR (diameter of 1μm) are woven in a manner to be mixed in a cylindrical braid 21 for integral formation. The organic fiber 22 having 100% modulus of 20kgf/cm2 and 600% elastic ductility is used. This constitution, when a cylindrical substance 2 changeable into an expansion state and a contraction state is brought into a contraction state, stretches the cylindrical substance 2 in a longitudinal direction and changes the cylindrical substance into a shape wherein insertion of the cylindrical body into a pipe to be contracted and reinforced is facilitated. Further, when the cylindrical body is inserted in a stretched state into the pipe to be reinforced, the pipe to be reinforced is shaped along the shape of the cylindrical shape. In this case, the restoration force of the cylindrical body 2 is equivalent to a force to which the elastic restoration force of the organic fiber 22 is added. Thereby, when a stretch force is released, the cylindrical body is disposed in a state to be extended along the inner wall of the pipe.
DOI SHOJI
IWAO KEIZO
TSUKIMOTO FUMIO
