Study On Shell-liquid Coupling Nonlinear Seismic Response And Isolation Measures Of Large-scale Liquid Storage Tank

Energy security is a global and strategic issue related to national economic and social development and national economic lifeline.The storage and transportation of petrochemical industry plays an important role in promoting the development of national economy,national defense construction and transportation.It is also known as the ’lifeline’ project.Ensuring energy security is always the primary task of China ’s energy work.Combined with the investigation of earthquake damage at home and abroad,it is found that the earthquake has a great destructive effect on the storage tanks in the key storage and transportation system of the petrochemical industry,and it will also bring secondary disasters,resulting in very heavy economic losses.In order to explore the failure mechanism of storage tanks under strong earthquakes,this paper studies large-scale anchored vertical steel storage tanks.The main research contents are as follows:(1)For the anchored vertical steel storage tank,the simplified seismic response calculation model is sorted out.Based on the potential flow theory and the boundary conditions of the storage tank under rigid foundation,the corresponding velocity potential function is derived.Based on this,a simplified storage tank isolation dynamic model under rigid foundation conditions is established,and the dynamic equation under horizontal ground motion excitation is given.Combined with the classical shell-liquid coupling theory,the real working mechanism of the storage tank is revealed,which lays a foundation for subsequent correct modeling.(2)The direct fluid-solid coupling method is used to finely model the anchored vertical steel storage tank in line with the actual situation of the project.In order to further test the correctness of the established finite element model,the natural vibration characteristics analysis is carried out.The sloshing mode and fluid-solid coupling mode of the tank are compared with the relevant specifications,and the corresponding vibration modes are analyzed to verify the reliability of the established finite element model.At the same time,a variety of liquid level conditions are set to explore the variation of the inherent characteristics of the storage tank under different liquid level conditions.(3)According to the layout of the isolation bearing of the storage tank in the actual project case,two different isolation bearing layouts are proposed,and the finite element model of the isolation tank is established.Based on the established finite element model of the isolated storage tank,a series of key parameters to measure the dynamic characteristics of the storage tank are extracted and compared with the non-isolated storage tank,so as to select a more reasonable arrangement of the isolation bearing.Research surface:The isolation measures adopted in this paper have obvious effect on reducing the dynamic response of storage tanks under earthquake action,which can provide some reference for the isolation design of storage tanks in engineering practice.