Floor response spectra of offshore electrical platform under sea waves and earthquake

Abstract

Offshore electrical platform plays an important role in gathering and transmitting the electric energy of offshore wind turbines. Various published works have studied the seismic performance of offshore platforms but these investigations are usually focused on the platforms and much less on the electrical equipment arranged on them. The electrical equipment is the nonstructural component on platform and is prone to failure and damage in the complex marine environment, causing the offshore electrical platform to lose its functionality. This paper aimed to fill in the knowledge gap in the study of the floor acceleration response spectra of offshore electrical platform. The finite element models of offshore electrical platforms were firstly established considering hydrodynamic effects and pile-soil-structure interaction. The influencing factors associated with the generation of platform floor acceleration response spectra were discussed under sea waves and earthquake. The empirical fitted formulas of platform floor acceleration response spectra were proposed to estimate fast and accurately the maximum absolute acceleration of electrical equipment. Finally, the accuracy of the proposed formulas was validated by comparing with the results calculated by time history analyses. The conclusions of this paper can be utilized in engineering practice to improve seismic design of offshore electrical equipment and decrease environmental loads damages to it.