Numerical study of lateral breakout resistance for shallow-embedded pipeline in sand

Pipe-soil interaction is the key to the on-bottom stability design of the submarine pipelines. Numerical analysis has been widely used because of its low cost, high repeatability, and strong visualization ability of soil displacement field, velocity field, and stress field during pipeline movement. With regard to the problem of breakout resistance of shallow buried pipelines in sandy soil, a numerical analysis model of pipe-soil interaction was established based on the hypoplastic model that can simulate soil anisotropy, porosity change, critical state, dilatancy or shrinkage characteristics of sand soil and ABAQUS finite element software; the resistance response mechanisms of shallow buried pipeline in sandy soil were studied separately under the constraints of load method (CL) and displacement control method (CD); the occurrence condition of “heavy-pipe” response in sand is clarified by analyzing the influences of parameters such as pipe weight and soil density on breakout resistance; compared with results based on the load control method (CL) and the displacement control method (CD), it is found that the soil resistance obtained by the load control method for “light-pipe” is larger than that obtained by the displacement control method, while the soil resistance of “heavy-pipe” is vice versa.