Abstract: A synthetic resin corrugated pipe includes a pipe wall having an annularly- or helically-shaped convex-concave surface. The convex-concave surface has a plurality of convex portions having a quadrangular cross-sectional shape and a plurality of concave portions having a circular cross-sectional shape.

Abstract: A pipe wall has an inner wall cylindrically formed of a soft material of rubber, synthetic rubber or synthetic resin, a rising rib bonded at its base portion onto an outer circumferential surface of the inner wall so as to extend therefrom in an outer circumferential direction, and an outer wall coupled at its base end portion with the rising rib so as to extend in an axial direction of the pipe in a position separated at a predetermined distance circumferentially from the inner wall, the rib and the outer wall being formed of a hard synthetic resin material and wound spirally, wherein only a top end portion of the outer wall is coupled with a preceding winding of the outer wall, and separable dividing portion is formed between the top end portion and the base end portion.