Seismic Analysis of a Large LNG Tank Considering Different Site Conditions
Seismic resilience of critical infrastructure, such as liquefied natural gas (LNG) storagetanks, is essential to the safety and economic well‐being of the general public. This paper studiesthe effect of different ground motions on large LNG storage tanks under four different siteconditions. Key parameters of structural design and dynamic analysis, including von Mises stressof outer and inner tanks, tip displacement, and base shear, are analyzed to directly evaluate thesafety performance of the
... performance of the large LNG tanks. Because the size of an LNG tank is too large to performany experiments on a physical prototype, Smoothed Particle Hydrodynamics‐Finite ElementMethod (SPH‐FEM) simulation is used as a feasible and efficient method to predict its seismicresponse. First, the accuracy of the SPH‐FEM method is verified by comparing sloshing frequenciesobtained from theoretical formulation to experimental results and SPH‐FEM models. Then, theseismic response of a real‐life 160,000 m3 LNG prestressed storage tank is evaluated with differentliquid depths under four site classes. Simulation results show that the tip displacements of the LNGtank at liquid levels of 25% and 50% under site class IV are nearly identical to that of 75% and 100%under site class II. In addition, the maximum von Mises stress of the inner tanks exceeds 500 MPain all four site classes and jeopardizes the structural integrity of large LNG tanks. As a result,optimization of structural design and the establishment of an early warning system are imperativeto the safety of LNG tanks at high liquid levels.