Seismic Isolation Design Research Of LNG Storage Tank

Since reform and open-up of China,Chinese economy has been developing rapidly.It is the first engine of the global economic development now.But it has made huge ecologic disaster that the structure of energy in China relies on coal seriously.With rapid economic development and environment-protecting requirements,domestic production and importing of natural gas as a clean energy will further increase.Large-scale liquefied natural gas(LNG)storage tanks in production and marketing aspects is essential.China is a multi-earthquake country,seismic zones are throughout it.LNG storage tanks and their safe operation is very important.Because of the earthquake damage,LNG storage tank fire and leakage will cause the loss of life and property as well as ecological disaster.Therefore,we must pay attention to the seismic isolation design of the LNG storage tank.In the beginning we Introduced LNG physical and chemical properties,safety issues and damage characteristics.Then we introduced the international and domestic demand of LNG.Mainly discussed the LNG storage tank isolation design and research and its development trends,revealing some researching problems,and then proposing the content of this study.In this paper,using pile foundation,aiming at large full-capacitive LNG storage tanks,consider the role of pile and soil,introducing base isolation and damping wall isolation measures,using of finite element numerical simulation analysis and shaking table test methods,we research seismic response of the LNG storage tank isolated.Aiming at seismic isolation design for LNG storage tank,the outer tank is simplified as cantilever beam,storage liquid is considered as ideal potential fluid,considering the role of the pile and soil,using horizontal seismic excitation,we finished the theoretical derivation and numerical example.Using ADINA software,we finished finite element numerical simulation analysis,and verified the theoretical solution.The results show that without base isolation,the role of the pile and soil showed weak effect,increasing and decreasing less than 20%.Considering the role of pile-soil results in a design will access closer to the actual situation.Base isolation is still irreplaceable damping measures.On the basis of the above analysis,damping wall is applied between the inner tank and the outer tank.With one-way horizontal seismic excitation,we finished the theoretical derivation and numerical example.The results show that in the case of no base isolation,damping wall has significant energy dissipation effect.In the case of base isolation,damping wall seismic energy dissipation effect is not obvious,further provided the importance and necessity of the base isolation.In the end,we have made the 1:5 scale tank model.We finished simulation shaking table test for steel bar bearing isolation system.Excitated by horizontal seismic waves,we obtained tank dynamic stress,displacement,sloshing wave height and acceleration seismic response by measuring the technical conditions of isolation and non-isolation,and we compared test result with the computational analysis result.In the end of this article,to the engineering point of view,we explored conventional design and seismic design method for large LNG storage tank.Then we summarized briefly the design of large-scale LNG storage tank isolation,finished a designment of rubber base isolation for 16×104m3 LNG storage tank,which will provide a reference for the LNG storage tank design.