Bearing Capacity of Pile Foundation Considering Mud Sand Mixing Layer Jacket Platform Limit

The design life of offshore fixed platforms is generally 20 years, but with the needs of oil field production, most of the platforms are still in service after reaching the design life, which further requires the functional expansion of active platforms and the transformation of new platforms relying on active platforms. In order to ensure the normal and safe production of the platform, a comprehensive safety assessment must be carried out on the platform. The bearing capacity assessment of pile foundation is an important part of the life extension assessment of the platform in service. This paper relies on a platform that has been in service for 25 years to carry out a certain transformation, and on the southeast side of the platform, a new platform with 8 legs and 12 piles is built as the core engineering facility. A new calculation method is adopted to calculate the ultimate axial bearing capacity of single pile of jacket platform pile foundation in the viscous soil layer and sandy soil layer. Based on the engineering geological characteristics of submarine soil, the ultimate axial bearing capacity of single pile and the mechanical analysis of jacket platform pile foundation, the load of jacket platform, bottom resistance, dead weight and lateral friction force are calculated and checked.