Numerical simulation and centrifuge test study on stability of gravity offshore platform in shallow sea

Based on the LD 29-1 marginal oilfield development project, combined with the shallow sea gravity platform design scheme suggested in "863" project, numerical simulation and centrifuge test were carried out, and the mechanical deformation characteristic of offshore platform structure and foundation deformation law were analyzed in this paper. According to the numerical result, the gravity platform had obvious lateral deformation under the action of horizontal load, the deck structure warped and the vertical settlement of surface foundation was large. According to the centrifugal model test result of 80g acceleration, under horizontal load, when the gravity platform had no bucket skirt, sliding deformation occurred mainly between the caisson and the foundation, and when the bucket skirt was added, the rotation deformation around the bottom plate occurred, while the gravity platform was inclined. The deformation degree of foundation can be reduced and the overall stability of the platform structure can be improved well by setting bucket skirt at the bottom.