Zhang, J.; Song, S.; Zhai, Y.; Tong, L., and Guo, Y., 2019. Numerical study on the wave-induced seabed response around a trenched pipeline. Journal of Coastal Research, 35(4), 896–906. Coconut Creek (Florida), ISSN 0749-0208.
The investigation of wave-induced seabed dynamic response in the vicinity of an offshore trenched pipeline is particularly important for analyzing the stability of a pipeline. In this study, an improved two-dimensional (2D) numerical model is used to investigate the wave-induced dynamic seabed response for manifold backfilled depths and the associated residual liquefaction under the wave loading. To calculate the accumulated pore pressure, the superstatic pore pressure accumulation Sassa model is improved by (1) extending 1D to 2D and (2) expressing the shear modulus using the soil plastic parameters. The improved model is first validated by comparing the simulation with the experimental data without a pipeline. The effects of wave and pipeline characteristics, such as wave length and height, pipeline diameter, and stiffness, on the wave-induced dynamic seabed response are simulated. The effects of backfill sand properties and backfill depth on pore pressure accumulation around a pipeline are examined. The results indicate that the influence of pipeline parameters on the dynamic response is only obvious in a certain scope and the possibility of pipeline instability due to soil liquefaction decreases with the increase of the backfill depth.