A New Method of Using Liquid Damper to Reduce the Displacement of the Monopile Offshore Platform against Seismic Loads

Abstract

The efficiency of a tuned liquid damper (TLD) in controlling the dynamic responses of offshore monopile platforms under seismic excitation has been investigated in this paper. Damping is performed by applying a type of reservoir inside a tower, which is designed optimally via seawater and a monopile body. Hydrodynamic forces due to water surface oscillation in the reservoir act as resistant forces against structure vibration and displacement. Using ANSYS finite element (FE) software, a monopile structure with the same dimensions as the samples in the Persian Gulf climate was modeled and then analyzed in this research using the transient time history analysis related to the records of El-Centro, Kobe, and Tabas earthquakes for seismic investigation. The dynamic responses of the monopile platform with and without TLD were compared after the completion of FE results. Findings show that using the mentioned TLDs reduced structure displacement by more than 50% based on the earthquake frequency content.

Keywords

Tuned liquid damper (TLD) / Offshore platform / Monopile platform / Seismic excitation / Dynamic response