Robinson Consultants provided engineering services for the trenchless rehabilitation of an existing 900 mm concrete pressure pipe (SS-P-381) sewer. The sewer is suspended on a pipe utility structure above a road, parking lot, and river. Services included the  assessment of available lining options, cost estimates, preparation of a predesign report, and detail design for Cured-in-Place (CPP) pipe lining, which was the  recommended option. The design had to consider the potential for significant thermal contraction and expansion due to the exposure of the pipe. A resin was selected with elastic properties beyond that of a typical polyester resin. Several key issues also had to be addressed for the installation process, including the potential for resin leakage out of the pipe during the curing process and the requirement for a watertight bypass flow process which was located above the river. The design included a traffic
control plan and bypass pumping plans, as well as structural repairs to the host concrete pipe. Services during construction included contract administration and full time inspection.