Western Canal Interceptor Junction Structure Rehabilitation
REHABILITATING A JUNCTION STRUCTURE USING FRP
Through routine inspection, the City of Tempe discovered a pipe segment and junction structure in need of rehabilitation located adjacent to the Western Canal, which is owned and operated by the Salt River Project (SRP). The existing junction structure was a 60-inch-diameter PVC T-lock lined concrete manhole approximately 16 feet deep providing access down to a 6-foot-wide by 6-foot-deep junction structure. The existing T-lock liner was observed to be failing in multiple locations, which further caused the deterioration of the junction structure and connecting pipes.
Dibble recommended replacing the junction structure, access manhole, and approximately 3 feet of each pipe connected to the junction structure. Our team recommended constructing the new junction structure and access manhole of corrosive-resistant polymer concrete. We also recommended that the new pipe connections be constructed of corrosion-resistant material with the internal transition to the existing T-lock lined pipe using fiber reinforced polymer (FRP).
The FRP strengthens and protects the system and provides a good seal at the pipe joints. The internal application of the FRP at the connection points does not reduce the inner pipe diameter and therefore does not change the flow volume of the pipe.
Dibble provided construction administration and special inspection services during the FRP installation.