The Design And Analysis On Vertical Step Back Steel Frame Structure With Top Layer For Gabled Frame

As the strengthening of the country's economic strength and the development of steel structure industry's technology,the function of industrial buildings tends to be multifunctional.In order to meet the needs of equipment layout and official business,The gabled frame and steel frame composite structure emerged.However,the technical codes does not refer to such structural forms.So the composite structure has a lot of value to be studied.This article use a 5 floors(3 floors of podium and 2 floors of top)steel structure plant which podium and tower top's floor parts are Gabled frames for background and design and analyze vertical-step-back steel frame structure with top layer for gabled frame by using project-contrast ways.Firstly,This article base on Technical Code for Steel Structure of Light-Weight Building With Gabled frames and Code for Design of Steel Structures.It try to using software PKPM establishes and analyzes the composite structural project model of the Gabled frames which the parts of Gabled frames are designed by Technical Code for Steel Structure of Light-Weight Building With Gabled frames and parts of Steel Structures are designed by Code for Design of Steel Structures.final,The reasonable design of flow vertical step back steel frame structure with top layer for gabled frame is obtained.Secondly,In order to study the seismic performance and advantages of the above project,the paper proposes two new projects-P2 and P3.P2 is the composite structure designed only basing on Code for Design of Steel Structures.P3 is that the composite structure changed the Gabled frames parts to steel frame,and the composite structure designed only basing on Code for Design of Steel Structures.The paper obtains the P2&P3 models by using software PKPM to design.Then,the paper uses response spectrum and elastic time history analysis under frequent earthquakes and elastoplastic time history analysis under rare earthquake with finite element software Sap2000 to study the seismic performance of the three projects.final,the paper get those results.First,composite structural project model of the Gabled frames which the parts of Gabled frames are designed by Technical Code for Steel Structure of Light-Weight Building With Gabled frames and parts of Steel Structures are designed by Code for Design of Steel Structures has good seismic performance under frequentearthquakes.Second,causing of braces yield,the seismic behavior decreased slightly.But meet the requirements of the codes,and the composite structure designed by two codes has advantages of economic performance.Thirdly,In order to study the structure dynamic property,the paper use finite element software Sap2000 to analysis influence of different podium's frame layers and different gabled frames' lateral rigidity of the podium's top layer and tower's top layer on composite structure's dynamic performance.The results show that first,in a certain range with the increasing number of podium's frame layers the natural vibration period of the structure and the flexibility of the structure increased.Second,with the increasing number of gabled frames' lateral rigidity of the tower's top layer,the storey drift ratio of tower's top layer between the horizontal and longitudinal directions of the structure are decreased.Third,with the increasing number of gabled frames' lateral rigidity of the podium's top layer,The longitudinal directional structure's storey drift ratio of tower's top layer and above in the is decreased and The horizontal directional structure's storey drift ratio of tower's top layer and above in is increasing.