Analysis On The Mechanical Behaviors Of Reinforced Concrete Deep Coupling Beams Of Frame-Tube Structure

Tube structure is one of the most widely used structural forms in high building,which is divided into four structures: frame-core tube,frame tube,tube in tube and beam tube.The frame-core tube structure,which has the advantages of the frame and shear wall structure,is a kind of anti seismic structure with excellent performance.In order to meet the requirements of the building function,the core tube usually needs to be opened,and the whole shear wall is divided into a joint shear wall connected through the connecting beam.The coupling beam is the first line of defense for the tube structure to resist earthquake.Its ductility and energy dissipation performance play a crucial role in the failure mode of the tube structure under the action of earthquake.Therefore,the seismic performance of continuous beam is a necessary prerequisite for aseismic performance of shear walls,which must be paid attention to.Research shows that the shear wall in frame-core tube structure forbuilding often need to form deep coupling beams,and the force performance is different from the ordinary beam.The traditional reinforcement methods are very difficult to meet the requirements of specification for reinforced structure design,so finding suitable reinforcement scheme coupling beam of small has important significance.This paper first uses Midas/Gen software for the overall analysis of a25 story frame core tube structure,and analyses stress performance under different average span of structure in changing the beam conditions,including layer displacement and maximum displacement,shear layer,layer stiffness weight ratio,cycle structure response.Then it uses the ABAQUS finite element analysis software to analyse the shear wall coupling beam and study on the mechanical performance of coupling beam under the condition of ordinary reinforcement,cross reinforcement,rhombus reinforcement,comprehensive reinforcement and other reinforcement forms,as well as the setting of through joints and half through joints.Some conclusions are drawn as follows:(1)When the span-depth ratio of the coupling beam is within the range of 2.0~1.0,decreasing the span-depth ratio of the coupling beam can enhance the lateral stiffness of the structure and make the structure have better resistance to deformation.(2)The new type of composite reinforcement beam has the advantages of diagonal reinforcement and rhombus reinforcement.It hashigher shear capacity and better ductility.It is a better reinforcement scheme.(3)The semi seam coupling beam show characteristics of self controlled coupling beams,which are not destroyed under small earthquakes and have high shear capacity.The multiple beams which are formed by the destruction of the weak layer concrete at the semi-through seam have good ductility under the large earthquake.(4)Compared with the semi seam double coupling beams,the shear capacity of the semi seam three coupling beams has not decreased obviously under small displacement deformation,although the stiffness of the semi seam three coupling beams is weakened.And the semi seam three coupling beams have better ductility performance under large displacement deformation.It is a good form of self controlled coupling beam.