Analysis Of Large LNG Storage Tanks Stochastic Seismic Response And Seismic Reliability

Large LNG storage tanks are prone to damage in the event of a strong earthquake. Once leakage occurs due to intolerable structural damage or liquid shake, it will trigger a series of secondary disasters, meaning catastrophic economic losses and social impacts. Earthquake occurrence is random. As a non-stationary random process, ground motion behaves significant characteristics of non-stationary both in intensity of and ground vibration frequency components. And now the time-history analysis of LNG tanks mostly focus on classical seismic engineering records, but still lacking in nonstationarity when considering construction site characterization and ground motion, therefore, analysis of LNG storage tanks at random dynamic response under seismic action and study failure modes of LNG storage tanks under earthquake seem to be of significant importance. Evaluation seismic reliability of LNG storage tank based on the theory of probability gives valuable guidance to decision and design of engineering structures. In response to these problems, this paper aims at study the large-scale LNG storage tanks of random earthquake response and seismic reliability analysis of LNG storage tanks by means of modern finite element method, concrete work as follows:Part 1:Apply the finite element model of a large LNG storage tanks a series of varying intensity ground motions, conduct parametric analysis to research relationship between LNG storage tank major seismic response and intensity;Part 2: Generate random seismic vibrations by power spectrum expression method based on improved model of Kanai-Tajimi spectrum, study the dynamic response of LNG storage tank under a non-stationary random ground motion.Part 3: Select seismic ground motion acceleration in line with the construction site characterization and dynamic property of LNG storage tanks with spectrum fitting method. Apply LNG tanks the selected ground motion, build maijor failure probability density curves by means of kernel density estimation method to solve seismic reliability of the LNG storage tank under rare earthquake, then get seismic reliability of LNG storage tank system in series.