Abstract: J-Lay system has been the most suitable laying method for large diameter subsea pipeline at present because of its advantageous pipeline laying form. In the process of laying large diameter submarine pipeline with J-Lay system, the effect of laying angle and water depth on the pipeline is of critical importance. Therefore, based on the catenary theory, the static analysis considering the factors above has been carried out in order to determine the suitable laying angle of large diameter submarine pipeline under different water depths. In addition, the time domain dynamic analysis has been conducted to study the influence of ship motion, current incidence angle and existing pipeline damage on the dynamic stress of pipeline, and the results can server as reference for engineering practice.

Key words: large diameter submarine pipeline, J-Lay system, static analysis, time domain analysis, parameter analysis