Numerical Modelling of the Creep Subsidence of an Ocean Lighthouse Constructed on a Reclaimed Coral Reef Island

Abstract

This work is to investigate the creep subsidence of a large-scale ocean lighthouse constructed on a reclaimed calcareous coral sand foundation (abbreviated to RCCSF thereafter) in the South China Sea (SCS). Firstly, two modified Burgers creep models, referred to as modified HBM and KBM, respectively, are proposed and validated based on several triaxial creep test results, and then both are implanted into ABAQUS. Secondly, the model parameters of the modified Huang’s Burgers Creep Model (HBM) and Kong’s Burgers Creep Model (KBM) for the RCCSF are carefully calibrated for the subsequent numerical modelling according to the creep tests conducted by us. Thirdly, based on the modified HBM and KBM proposed in this study and the calibrated model parameters, the subsidence of an ocean lighthouse constructed on a reclaimed land in the South China Sea is numerically analyzed. The numerically predicted results illustrate that the creep subsidence of the ocean lighthouse in the future 50-year is 17.2 mm to 42.5 mm, meeting the mandatory requirement (<200 mm) stipulated by the China national design code. Finally, the sensitivity of the predicted creep subsidence to the model parameters is screened by performing parametric analysis.