Behavior of Sliplined Corrugated Steel Pipes under Parallel-Plate Loading

Some culverts and pipes installed under roadways several decades ago are reaching the end of their service life. The excavation and replacement of these buried structures will cause disruption to their service and require significant funding. Trenchless methods (e.g., sliplining) have been increasingly used to rehabilitate deteriorated buried structures (e.g., corroded steel pipes). Sliplining involves the placement of a new pipe liner inside an existing deteriorated pipe and the grouting of the space between the liner and the existing pipe. In this experimental study, parallel-plate loading tests were carried out to evaluate the effect of sliplining on the behavior of corrugated steel pipes with different degrees of corrosion. The nominal diameters of the corrugated steel pipes and polyvinyl chloride liner were 305 and 254 mm, respectively. This study investigated three different degrees of simulated corrosion of the steel pipes (0%, 50%, and 90%). The corrosion in each steel pipe was simulated by cutting out some steel segments along the invert of the pipe. A low-strength, normal-density grout was used to fill the space between the steel pipe and the liner. The pipes without and with sliplining were tested for their load-carrying capacity, stiffness, vertical and horizontal diameter changes, and average strains and curvatures. The experimental results show that prior to sliplining, the steel pipe with a 90% cutout behaved in a stiffer manner than that with a 50% cutout at a higher applied load. After sliplining, however, the steel pipe with 50% corrosion behaved in a stiffer manner than the pipe with a 90% cutout. Sliplining increased the load-carrying capacity and stiffness of the pipe. The location of the liner relative to the existing pipe had a minor effect on the behavior of the sliplined steel pipe.