Enhancing the Life Cycle of the Jack up Structure by Applying Alternative Foundation Methodologies in Geotechnical Engineering

Abstract

A jack-up structure is a bottom-mounted floating unit having an adjustable hull and movable legs. Particular jack-up structures are more susceptible to hazards under environmental loads during their operation and life cycle in the ocean. Authors' attempts here to enhance its life cycle and sustainability in shallow to deep waters by correctly accessing soil behaviour and predicting its load carrying capacity. Here the numerical analysis of the substructure has been attempted. Simulation of load-deformation behavior under axial compression has been carried out for advancing research. The entire study has been carried out using three-dimensional finite element-based software Plaxis 3D A.E. 2017. The geometrical variation of substructure spud can have an inverted spud at the centre bottom from 120 0 to 180 0 has been studied for knowing behaviour under axial compression, axial tension, and lateral forces. The simulated numerical model is used to develop empirical expressions for axial capacities estimation. The numerical analysis results indicate that spud can have an inverted angle of cone 130 0 is most beneficial under the static combined vertical, moment, and horizontal loading (3D loading) in marine clay. The axial load carrying capacities in compression, tension, and lateral loading follow the same sequence in ascending order from 180 0 ,175 0 , 150 0 , 130 0 and highest in 120 0 . Stiffness and undrained shear strength of soft clay contribute more than the diameter of the spud and embedment depth in compression and tension.