Trenchless Spiral Winding Technology for nationwide Sewer Rehabilitation. Spiral Winding for Trenchless Sewer and Stormwater Pipe Rehabilitation

Stormwater and sewage pipes span the entire territory of Nationwide. Some pipes in older districts have been in service for over 30 years; sewage pipes, in particular, are prone to accelerated aging and deterioration due to prolonged exposure to corrosive gases generated by sewage. The Drainage Services Department is progressively rehabilitating high-risk underground pipes, employing trenchless repair methods—which do not require excavating the road surface—whenever possible to minimize inconvenience to the public.

"Trenchless" pipe rehabilitation involves excavating only a small, temporary shaft at specific locations along the existing pipeline to insert new pipe materials into the old pipe, thereby forming a new conduit. This method requires minimal excavation and has a relatively short construction period, significantly reducing the impact on the public.

"Spiral winding" is one such trenchless rehabilitation technique. It utilizes a specialized winding machine to spirally wind steel-reinforced polyethylene strips into a tubular shape, creating a new pipe within the existing one. This technique is suitable for pipes that remain in operation, eliminating the need to divert the flow.