Shock Absorption Technology And Theory Of Elevated Vertical Cylinder Storage Tanks

With the development of petrochemical industry,construction industry,offshore platform,elevated storage tanks is still playing a very important role.It is directly related to the safety of human life and property once elevated vertical cylinder storage tank is suffered earthquake disaster.In order to reduce the destruction of elevated vertical cylinder storage tanks in devastating earthquakes,five kinds of vibration reduction methods are proposed for the structure characteristics of vertical cylindrical storage tank based on the research of domestic and foreign scholars,which are base isolation,top isolation,additional viscous dampers,combined shock absorption of base isolation and viscous dampers,combined shock absorption of top isolation and viscous dampers.In this paper,the seismic response of ground motion is studied from two aspects of theoretical research and finite element numerical simulation analysis,the research contents are as follows:1.Seismic isolation theory of elevated vertical cylinder storage tanks: Put forward the new anti-seismic,base isolation,top isolation simplified mechanical model and motion control equation,as the support is dispersed into a plurality of concentrated particles.The response of different ground motion inputs is compared and analyzed by numerical integration method.The result was indicative: the seismic response of the structure can be reduced effectively by using isolation measures,In addition to the sloshing height.Vibration reduction rate of two kinds of shock absorption methods is little difference.The appropriate isolation period should be selected for different site types in isolation design.2.Damping theory of additional viscous dampers for elevated vertical cylinder storage tanks : Damping model with additional viscous dampers and motion control equation are established.The ground motion response of different velocity index,different damper configuration scheme and different ground motion input were compared and analyzed,the result was indicative: The viscous damper is not sensitive to the frequency of ground motion,and has good damping effect;By attaching on the support structure with viscous dampers can reduce the sloshing height in a certain extent.It is suggested that the optimal design of damping parameters and configuration scheme of viscous dampers is considered in the engineering practice3.Combined shock absorption theory of elevated vertical cylinder storage tanks: The simplified mechanical models of two types combined shock absorption are established.The damping effect of different vibration modes with different ground motion inputs,differentliquid storage heights,different velocity indices and different ground motion peak values were compared and analyzed,the result was indicative: The vibration reduction rate of combined shock absorption measures is higher than a single shock absorption measures and whose advantages are closely related to the speed index.The selection of passive control mode should be based on the actual situation of the seismic requirements and site conditions of the actual project,and select the most appropriate way to shock absorption.4.The finite element numerical simulation analysis of isolation elevated vertical cylinder storage tanks: Elevated vertical cylinder storage tanks base isolation and top isolation finite element model are established.Research seismic response of base isolation elevated vertical cylinder storage tanks with different parameters such as isolation layer damping ratio,isolation periods,different ground motion input and height of liquid storage,the result was indicative: The seismic response can be effectively controlled by using isolation measures,which can improve substructure design of elevated vertical cylinder storage tanks,shrinking sectional dimension,and cost saving.The vibration reduction rate of base isolation and top isolation is closely related to the isolation period and isolation layer damping ratio.Seismic isolation design of elevated vertical cylinder storage tanks must consider a variety of parameters and various forms,and select the best isolation design designing scheme.5.Viscous damper finite element numerical simulation analysis of elevated vertical cylinder storage tanks: Elevated vertical cylinder storage tanks viscous damper finite element model is established,and seismic response analysis was carried on.The result was indicative:The viscous dampers methods have better control effect on rigid mass component,and the control of sloshing component is limited,that is limited for sloshing height.6.Combined shock absorption system finite element numerical simulation analysis of elevated vertical cylinder storage tanks: Elevated vertical cylinder storage tanks combined shock absorption system finite element model are established.For different ground motion inputs,five kinds of shock absorption methods are compared and analyzed.The target which is not reached recalculate by enhancing the strength of the viscous damper recalculate.The result was indicative: When the combined damping measures are adopted,the displacement of isolation layer is small,which is beneficial to the isolation layer and structure.From the point of view of energy consumption,when using the combined shock absorption measures,two kinds of shock absorption measures play their full role,which is more reasonable configuration;The measures of the viscous dampers and combined shock absorption have better adaptability than the isolation measures,which have better shock absorption effect in the four kinds of seismic action,especially in the control of inter story drift.The selection of vibration reduction method should consider the influence of many factors,which should be economic and reliable.7.To verify the accuracy of the results,the theoretical value and the finite element value of the vibration mode and the ground motion response are compared,The result was indicative: The theoretical solution and the finite element solution are close,and the accuracy of the calculated results is verified.