Dynamic Pressure of Seabed around Buried Pipelines in Shallow Water

Due to the obvious nonlinear effect caused by the shallow waves, the nonlinear wave loads have a great influence on the buried pipelines in shallow water. In order to ensure their stability, the forces on the pipelines that resulted from nonlinear waves should be considered thoroughly. Based on the Biot consolidation theory and the first-order approximate cnoidal wave theory, analytical solutions of the pore water pressure around the buried pipelines in shallow water caused by waves are firstly derived in this paper. The dynamic response of the seabed around the pipelines under the action of irregular waves is explored in laboratory, and the results are compared with the analytical ones. Experiments show that the maximum value of the pore water pressure is at the upper part of the pipelines, and the value at the bottom of the pipelines is the minimum. The pore water pressure amplitude at the upper half of the seabed that arises from waves has a larger fluctuation, and the amplitude at the lower half remains stable. For the sandy seabed, the pore water pressure at the same depth changes over time, with the fluctuating amplitude, and the theoretical values meet well with the test results.