Study On Seismic Behavior Of Mega-Frame With Frame Floors Changing

The structure of the mega-frame building is increasingly being widely used for construction engineering for its applicability, potential and efficient structural performance. Mega-frame structure is made of two components structure, the primary structure and the secondary one. It has many advantages, such as clear power transmission, wonderful overall performance, fast speed in construction, flexible layout. Besides, it can save materials and reduce cost. It has broad application prospects in the high and ultra-high-rise buildings. There is important theoretical and practical significance to carry out the study on seismic performance analysis of mega-frame structural system.This paper studied the seismic performance of mega-frame with the structural frame floors changing. Analyzed from two aspects, one aspect analyzed the increased number but evenly arranged of main frame beams, the other analyzed the same number but non-uniform arrangement of main frame beams. Based on the finite element theory, using the large finite element software SAP2000, this paper established three models for the two aspects, and carried out modal analysis and dynamic analysis according to three seismic waves. Comparing with basic natural period, the floor displacement, story drift angle, maximum top-level acceleration, story shear force and base shear in the three models, seismic performance is evaluated.Compared modal analysis with dynamic time history analysis of increased number but uniform arrangement giant beams of mega-frame structure in the three models, it can be known that with the increasing number of main frame beams, the greater stiffness the structure has, the greater seismic energy the structure absorbed, the smaller the basic cycle is, the smaller the floor’s lateral is, the smaller of the largest top-level acceleration it has. But, base shear will increase with the floor shear increasing.Compared modal analysis with dynamic time history analysis of the same number but non-uniform arrangement giant beams of mega-frame structure in the three models, it can be known that with the same number but down layout of giant beam, the greater structural stiffness it has, the greater seismic energy the structure absorbed, the smaller the basic cycle is, the smaller the floor’s lateral is. But the largest top-level acceleration would increase, the floor shear would increase and base shear also would increased.It can be concluded from the two aspects’calculations:the seismic performance of mega-frame structure is not better with the increased number of giant beams and closer to arrangement. of low part of floors. It should pay attention to optimizing the layout of the main frame beams to enhance the seismic performance while designing mega-frame. Figure [56] table [14] reference [56]...