Laboratory Load Tests on Buried Flexible Pipe. Progress Report No. 5. Fiberglass Reinforced Plastic (FRP),Polyethylene (PE),and Polyvinyl Chloride (PVC) Pipe,

摘要

Laboratory tests were conducted to investigate the behavior of buried flexible pipes. Kinds of pipe tested were fiberglass reinforced plastic (FRP),polyvinyl chloride (PVC),and polyethylene (PE). The pipes were buried in a large,steel,soil container in a lean clay backfill. A large universal testing machine was used to apply surcharge loads to the soil surface over the pipe. Measurements of the changing dimensions of the pipe,strain on the inner surface of the pipe,soil movement around the pipe,and soil pressures were made during a one-day loading sequence. Test results are presented and deflections under load are compared to tests of steel pipe and of reinforced plastic mortar (RPM) pipe. The FRP pipe deflected similar to the RPM pipe,while PVC pipe and PE pipe showed a similarity to steel pipe. Three-edge bearing tests used to determine pipe strength did not provide a reliable basis for predicting the deflection of different kinds of pipe. Deflection values varied as much as 300percent for different kinds of pipe even though their three-edge bearing load-deflection curves were identical. The study showed that FRP pipe deflects differently than steel,PVC,or PE pipe,and that care must be taken to assure proper bedding of the FRP pipe.