Study On Performance Design Method And Seismic Performance Of Hybrid Coupled Wall Structures

Reinforced concrete coupled shear walls are widely used in high-rise buildings in China.However,reinforced concrete coupling beams often cannot meet the huge ductility and shear force requirements.Researchers and engineers have begun to use steel coupling beams with good ductility and shear capacities instead of reinforced concrete coupling beams.The resulting structural system is referred to as a hybrid coupled wall system.Reasonably designed hybrid coupled wall system can fully utilize the respective advantages of steel and concrete.However,due to the differences in the ductility requirements and capacities of the steel coupling beams and reinforced concrete walls,the design method and seismic performance of the hybrid coupled wall system are complicated.At present,the research on the hybrid coupled wall system in China has just started and is far behind the engineering practice.Therefore,it is of great significance to conduct research on its design method and seismic performance.In this paper,based on the mechanical properties of hybrid coupled wall system,the plastic coupling ratio was selected as the main design and research parameter from the four types of coupling ratios.The plastic design method based on the energy balance of the hybrid coupled wall system was deduced and the complete design flow was given.Based on the design method,12 cases were designed.Static analysis and nonlinear dynamic time history analysis were performed on 12 cases.Based on the analysis results,the rationality of the design method was verified,and the values of several key parameters involved in the design were studied.Then,the seismic responses of hybrid coupled wall system with different layers and different plastic coupling ratios were comprehensively analyzed,and the effects of plastic coupling ratios on seismic response of hybrid coupled wall system with different layers were studied.Taking into account the bearing capacity and deformation ability of the structure,the reasonable values of the plastic coupling ratio for hybrid coupled wall system with different layers were given.The main conclusions of this paper were as follows:(1)The coupling ratio is an important parameter affecting the seismic performance of the hybrid coupled wall system.This paper analyzed the mechanical properties of the hybrid coupled wall system and compared the difference between the steel coupling beams and the reinforced concrete coupling beams.Summarizing the four types of coupling ratios present in the current study,it was considered that the plastic coupling ratio is more appropriate as the main design and research parameter.(2)The derivation of plastic design for hybrid coupled wall system based on energy balance was conducted according to the performance-based plastic design method proposed by Lielataviwat and Goel.And a complete design flow was given.(3)Based on the results of static analysis and nonlinear dynamic time history analysis,suggestions were given on several key issues in the design process.The parameter ? in the lateral force distribution pattern was recommended as 0.6.Proportions of wall moment demands under varying coupling ratios were given.It is suggested that the overstrength factor in the bending design of the reinforcement concrete wall is 1.1.(4)Considering the yield mechanism of the structural system,the story drift ratio and the damage distribution,this paper proposed that the reasonable values of the plastic coupling ratio are 30%~40% for lower structures and and 50%~60% for higher structures.(5)Using the plastic design method of this paper,due to the redistribution of internal forces and yield strengthening of each component,the structure still has a certain degree of overstrength.(6)For the hybrid coupled wall system with different layers,increasing the plastic coupling ratio can significantly reduce the structural deformation,yield displacement ratio,ultimate displacement ratio and the ductility factor.(7)The maximum base shear force of the nonlinear dynamic time history analysis is much larger than the design base shear force,and the designed overturning moment is consistent with the nonlinear dynamic time history analysis.It shows that the base shear force of the structure is greatly affected by the higher modes,and the overturning moment is less affected by the higher modes,and the lateral force distribution used in this paper can obtain a reasonable overturning moment.