Full-Scale Field Tests on Longitudinal Uplift Response of Corrugated Metal Pipe

Abstract

In response to problems with corrugated metal pipe (CMP) culvert uplift failures caused by unbalanced inlet hydraulic loading, full-scale field testing and numerical analysis were undertaken to develop a rational design methodology for CMP inlet tiedowns. Four uplift tests performed on a 2.44-m-diameter CMP under different backfill cover, foreslope, and restraint conditions are described. The objectives of the tests were to gain insight into the soil-structure interaction processes and to provide data for verification of the performance of the finite-element model used to calculate the required restraint forces. The test results indicate that the backfill foreslope has a significant effect on uplift response. For example, the force required to lift the CMP inlet 25 mm was about 50 percent greater with 0.6 m of backfill cover and a full 2:1 foreslope than with 0.6 m of backfill cover and approximately 4 m of the CMP exposed beyond the toe of the backfill foreslope. These results indicated that appropriate modeling of the soil-structure interaction and interface behavior in the foreslope region is extremely important.