Using Dune Sand in Controlled Low-Strength Material for Backfilling: Field Installation and Numerical Simulation

Abstract

The deflection of buried pipes depends on the exerted load and the embedment material. The portion of the exerted load transferred by the embedment material depends on the stiffness of the embedment material relative to that of the pipe. In the current study, four glass-reinforced polymer (GRP) pipes were buried in two different locations at the same depth under different geotechnical and installation conditions. For each of the test locations, two installation methods, namely controlled low-strength material (CLSM) and crushed rock, were used. The CLSM mixes were designed based on available native soil to satisfy the flow and strength criteria. Pipe deflection was meticulously measured at different stages of installation. In both cases, the behavior of the pipe showed the superior performance of CLSM as the backfill material. The behavior of the pipe was also evaluated by numerical modeling. The results of the numerical simulation were then compared with field test results, which showed a reasonable agreement. The pipe deflection was also predicted by a semiempirical equation and a numerical solution for the hardened CLSM. The effect of trench width on the vertical deformation was also evaluated through a parametric study.