Experimental Research Of Seismic Behavior Of Coupling Beams With Efficacious Detailing Of Shear Walls Resistance

Coupled walls include two or more single shear walls connected by coupling beams, which are the first line of energy dissipation under earthquake. So coupling beams' strength, stiffness, ductility and energy dissipating capacity can effect shear walls' performance directly. For the purpose of the architecture, sometimes depth-to-span ratio of coupling beams is very little, so coupling beams are subjected to great moment and shear, and distribution of stress and strain is very complex. The results indicate that it is impossible to avoid shear failure only by adjusting the ratio of the longitudinal reinforcement to the transverse reinforcement. In China Code for Design of Concrete Structures (GB 50010-2002), there are no design methods for coupling beams when the depth-to-span ratio is less than 2.5, which is one of the critical problems of the code for design of concrete structures unsolved. In this paper, there are three main purposes to be attained. Firstly, enough ductility of coupling beams is needed, namely no shear failure occurs too early. Secondly, the capacity of energy dissipation is satisfied on the grounds of enough stiffness. Thirdly, reinforcement detailing of coupling beams can not be too complex. The research contained the following five parts:1. Five coupling beam specimens were designed and fabricated under the requirements of China Code for Design of Concrete Structures (GB 50010-2002) and the Code for Design of Reinforced Concrete high-rise Structure (JGJ 3-2002). Tests were conducted by reversed cyclic load.2. Coupling beams' stresses and strains were analyzed with the development of cracking.3. Coupling beams' failure mode, shear distortion, ductility and energy dissipation were impacted by different shear-compression ratio from 0.15 to 0.20.4. Coupling beams' stresses, strains and the development of cracking were effected by different grade concrete.5. The development of cracking was effected by the different longitudinal and transverse reinforcement.The results from the test show the fact that ductility (>5.0) and energydissipation is more satisfied than other sheared beams. The new coupling beams without too deep beam-depth are easier to construct than diagonally reinforced coupling beams. Therefore, the new detailing of reinforcement concerning coupling beams is recommendable.