Seismic Control of LNG Storage Tanks using MR Damper

The paper aims to focus on the semi-active control behaviour of base-isolated liquified natural gas (LNG) Storage tanks under six artificial earthquake ground motions compatible with Operational Basis Earthquake (OBE) and Safe Shutdown Earthquake (SSE). The LNG storage tank is seismically isolated using High Damping Rubber Bearing (HDRB) Isolation system. The storage tank is analyzed for maximum operating level of LNG (full-level) to compute the seismic response under six artificial accelograms compatible to OBE and SSE earthquakes. In order to investigate the effective of semi-active control device in form of MR damper the seismic responses are compared with uncontrolled, base-isolated and controlled strategies. The seismic response quantities considered for the analysis included displacement at isolation level, total pile shear, base-overturning moment and sloshing wave height. The numerical results of the study demonstrated that controlled system in form of MR damper along with isolation system is significantly reducing the response of the LNG Storage tank specifically the displacement at isolation level without much modification in other responses.