Analysis Of Seismic Performance Of Steel-concrete Vertical Combination Structure

In recent years, reinforced concrete frame connected steel structure buildings are getting more and more in industrial. The kind of buildings are combined with two parts, the lower part is reinforced concrete frame structure, the upper part is steel structure, they have the characteristics of complex structure, dynamic characteristics by the equipment, carries on the analysis of seismic performance of its is the key point and difficult point of structure design. At present, the domestic and foreign researches on the seismic performance of this kind of structures are less. Therefore, it has practical significance to study the seismic performance of reinforced concrete frame connected steel structure factory building structure.For the overall steel-concrete vertical combination structure, since the upper and lower quality and stiffness are greatly different, thus forming a vertical irregular “rigid bottom and flexible upper” on the structure. The overall quality, period, stiffness and damping ratio of the structure will change. At present, seismic design provisions about the “rigid bottom and flexible upper” structure are no perfect seismic design code in China. In practical engineering, is often a separate analysis of the calculation of the steel structure, it is not reasonable, the design is not safe, should be on the overall structure calculation and analysis.This paper introduced the basic theory and analysis method for seismic design of buildings, including the motion equation and solving, earthquake effect analysis method and to investigate the seismic precautionary criterion etc.For the research of seismic performance of steel-concrete vertical combination structure, this paper combines with the actual project, a magnesium metal engineering dehydration workshop in Golmud, Qinghai province as background, from the angle of seismic design of structure, selection and structure arrangement of this kind of structure is discussed.In this paper, using the universal finite element analysis software SAP2000 to establish three-dimensional finite element model of the whole structure, and in the analysis respectively on the bottom reinforced concrete frame, the upper steel structure and the whole structure under frequent seismic, modal analysis, response spectrum analysis and dynamic time history analysis is carried out, study on the period variation, the layer displacement and displacement angle, shear between the interlayer, etc., as well as the overall structure dynamic characteristics.In this paper, the conclusion obtained is that the whole steel- reinforced concrete frame vertical combination structure is mainly with concrete, when the upper steel structure accounts for the proportion in the whole structure is small; the overall structure using constant damping ratio of 0.05 is able to meet the requirements of engineering design.Through this research, the research of steel- concrete frame vertical composite structure will be further improved, obtained the conclusion has certain reference value for engineering design.