Prediction of the potential tilt of tripod-bucket jacket foundation considering the effect of spudcan installation

Abstract

As a new type of offshore foundation, the tripod-bucket jacket foundation has gradually been applied in deep sea and far sea areas with its advantages of strong overturning ability and easy installation. The new tripod-bucket jacket foundation is often installed in stages using a jack-up platform. The jack-up platform needs to enter the site many times. As the foundation of jack-up platform, the spudcan that provides support for the jack-up platform affects the stability of the adjacent in-place tripod-bucket foundation during spudcan installation. This paper studies the effect of spudcan installation on the adjacent in-place tripod-bucket foundation based on large deformation finite element (LDFE) analysis. Firstly, verification analysis was conducted to demonstrate the accuracy of the LDFE approach by comparing it with established knowledge. Subsequently, combining the soil flow mechanism, the bucket motion during spudcan penetration was studied. Systematic parametric studies on soil properties and spudcan-bucket spacing in clay and sand were carried out to investigate bucket stability. Practical judgment methods for assessing bucket stability in clay and sand were proposed. Based on the bucket stability evaluation for a field case, the judgment methods were validated and can provide a reference to the industry.