Study On Seismic Behavior Of Hybrid Coupled Wall With Replaceable Steel Coupling Beams

In this thesis, the hybrid coupled wall(HCW) composed of replaceable coupling beams and conventional RC wall piers was proposed. A high-efficiency numerical model based on OpenSees was developed for this hybrid coupled walls. Numerical study on the seismic beahvior and earthquake resilience capacity was carried on. Design recommendations on the selection of coupling ratio(CR) and overstrength factor(Ω) were proposed on the basis of parametric study.The behavior of shear walls, shear links, normal segments of replaceable steel beams were simulated by using a multi-layer shell element, link element and displacement-based beam-column element, respectively. The slippage behavior between shear link and normal segments and the hysteretic behavior of RC coupling beams were represented by link element as well. The numerical model was able to predict stiffness, strength, deformation and energy dissipation capacities with a reasonable level of accuracy through comparison between numerical results and test data.One typical hybrid coupled wall(HCW) was selected from a prototype structure in which the replaceable steel coupling beams were appied. Pushover analysis and nonlinear dynamic analysis were carried on and the analysis results indicated that:(1). the yielding mechanism was achived that coupling beams yielded prior to wall piers,(2) neither failure in compression or tension with small eccentricity nor shear failure occurred at the bottom of wall piers under major earthquake ground motions,(3). the lateral deformation was in a bending mode, and the interstory drift ratios did not exceed the limits specified by the current design codes,(4) more energy was dissipated by the copling beams in the lower stories(i.e. below the 6th floor), while less enery was dissipated by the coupling beams in the upper stories,(5) HCW achived the same yield mechanism as RC coupled wall(RCW), and HCW had smaller deformation demand and better earthquake resilience capacity under major earthquake ground motions comparing with RCW.Parametric analysis indicated that:(1). the value of CR significantly influence the yielding mechanism of HCW,(2). excessive coupling ratio lead to higher shear demands and lateral deformation demands in wall piers, and less energy dissipated by coupling beams.(3). increased overstrengh factor, Ω, induced more dispersive distribution of plastic hinges of coupling beams, higher shear demand, larger lateral deformation demand, less energy dissipated by coupling beams and casued serious damage of wall piers. On the basis of parametric study, the value of CR ranging from 0.5 to 0.6 and moderate overstrength factor, Ω, was recommended for the seismic design of HCW, and LY225 steel and Q235 steel were recommend to be selected as the web material of shear links.