Load-Bearing Behavior of Pipe-Arch Corrugated Steel Pipes during Backfilling

Corrugated steel pipes (CSPs) are widely used in highway bridges and underground engineering. Before backfilling at the crown level, the soil cannot effectively support the structure, so the mechanical behavior of pipe-arch CSPs needs to be investigated. This study provides a comprehensive analysis of pipe-arch CSPs by investigating their mechanical behavior during backfilling. A theoretical model was built and tested using two widely used field-test examples. The theoretical maximum values and trends of bending moment and deformations were consistent with the results of the examples. In addition, a laboratory test was conducted on a pipe-arch CSP, and finite element (FE) models were developed. The measurement results other than that of the crown were relatively consistent with the theoretical results. The results obtained from linear theory and FE analysis were highly consistent. Further, the influence of the lateral pressure coefficient, coefficient of foundation, radius, corrugation, and steel plate thickness on the mechanical behavior of CSPs was investigated. The deep corrugated steel plate demonstrated high flexural rigidity, significantly reducing structural stress and deformation. Perturbation techniques were used to obtain the nonlinear results of pipe-arch CSPs when backfilling at the crown level. The formula for the nonlinear increasing rate of radial deformation, axial deformation, and bending moment was provided, along with a simplified expression for maximum vertical deflection of the pipe-arch CSPs before backfilling at the crown, which can be used to prevent damage during the backfilling of CSPs in practice. The study findings contribute significantly to understanding the mechanical properties of pipe-arch CSPs.