Seismic Performance And Isolation Effective Of Large Vertical Liquid Storage Tank

With the intensification of the global energy crisis and oil price inflation,people focus their attention on how to increase strategic reserves of energy to reduce the impact on China's economic system from the volatility of world oil price.Thus,vertical floating roof storage tank in which flammable and combustible amboceptors are stored becomes strategic facilities,and how to protect its safety from serious natural disasters and reduce their economic losses and the disastrous effect such as in earthquake has become the major subject for researchers.The shaking table test is the ideal method for seismic response study on storage tank,but is limited its wide application due to its time-consuming,high cost.At present,simplified theoretical approach is widely used in the seismic response analyses of liquid storage tanks field.With the development of finite element numerical analysis method,three-dimensional finite element numerical simulation becomes another important research tools.The paper introduces the anti-seismic base isolation structure for large vertical steel floating roof tanks,and studies the seismic response of base isolation floating roof tanks by numerical simulation finite method and shaking table test method,taking the impact of floating roof and multi-dimensional seismic excitation into account,which reads as follows:1.Considering the material nonlinearity of the tank wall,liquid-solid coupling between the storage liquid and the tank wall,the finite element analysis model of a large vertical floating roof and non-floating roof storage tank are established to calculate the seismic respond of base isolation tank structure and the traditional one respectively.2.Shaking table test of seismic response to the storage tank with or without floating roof were presented,and the seismic performance of storage tank are studied.Based on the experimental method,the numerical analysis methods reliability is verified.3.The effectiveness of numerical analysis solution of base isolation and non-isolation storage tank structure are verified by theoretical methods.The results indicate that 3D numerical simulation method is feasible and effective.4.The paper studies the effects of floating roof on seismic response of the traditional seismic tank structure in different foundation conditions,different earthquake intensity,multi-dimensional earthquake excitations and the effects of floating roof on seismic response of the base isolation storage tank structure in different earthquake intensity,isolation periods,isolation layer damping ratio and multi-dimensional earthquake excitations.The necessity of considering three-dimensional earthquake action is pointed out and the appropriate conclusions are given.5.The seismic response parameter influence analysis of the base isolation tank structure with floating roof is carried out.The results indicate that the earthquake intensity and the selection of seismic waves have significant influence on the sloshing wave height but have little influence on the other seismic response.6.Selecting large storage tanks with floating roof as research objects,dynamic buckling characteristics under three-dimensional earthquake excitations are studied,and the dynamic buckling load of base isolation storage tank is compared with that of non-isolation storage tank to verify the effectiveness of the base isolation system from the angle of stable.The results indicate that the base isolation system can effectively increase the dynamic buckling load.