Performance evaluati on of 48” diameter corrugated high density polyethylene pipe under 315,000 lbs rail car loading [PE]

The Plastics Pipe Institute (PPI) sponsored testing of 48” diameter corrugated high density polyethylene (HPDE) pipe under heavy haul railroad loading with minimum cover to field verify LRFD calculated values. Testing was conducted at the Facility for Accelerated Service Testing (FAST) at Transportation Technology Center, Inc. (TTCI). Heavy haul loading consisted of four locomotives and eighty 315,000 lbs rail car that cycled over two 48” diameter HDPE pipes at 40 mph until 100 Million Gross Tons (MGT) had been reached. The first pipe was backfilled with fabric wrapped and vibrated in place 57 stone. The second pipe was backfilled with onsite ASTM Class III backfill that was compacted to 94% of the Standard Proctor Density. Each pipe had a 58” long instrumented section that was joined in place with a split band coupler and an inline bell/spigot connection. Joints were placed directly under the rail to ensure maximum loading. Deflection gauges, strain gauges, circumferential shortening gauges, and joint separation measurements were used to evaluate the pipes and joints. Each pipe had four feet of cover from the bottom of tie to top of pipe. At the conclusion of the 100 MGT load cycle, all pipe measurements were well within allowable tolerances, verifying that the AASHTO Section 12 minimum cover height calculations align with pipe performance. The most exciting portion of the test was the video and data cycles of the heavy haul live loading and the visual evidence of elastic soil behavior. The test verifies that corrugated HDPE pipe will withstand heavy haul rail loading over large load cycles.