Study On Seismic Behavior Of T-shaped RC Walls

T-shaped reinforced concrete(RC)wall are commonly used in high-rise buildings.Through full-scale experimental tests and numerical analysis,this thesis investigates the influence of length of special boundary elements and volumetric ratio of boundary transverse reinforcement on strength capacity and seismic behavior of T-shaped walls.Based on this study,the design methods recommendations are proposed for special boundary elements of T-shaped walls.Quasi-static tests were conducted on three specimens to examine the seismic behavior of T-shaped RC walls under high axial force ratio.Three different specimens were designed in accordance with GB 50011-2010,ACI 318-14 and an improved design methods,respectively.The major difference among those three specimens were length of special boundary elements and the volumetric ratio of boundary transverse reinforcement.The test results indicate that the damage to T-shaped walls is mainly concentrated in the web end,including the crushing of concrete and bulking of vertical reinforcement,while the flange was slightly damaged only with a few cracks.When the flange was in compression,three specimens showed nearly identical behavior,although they were designed with different boundary element at flange wall.It indicates that the special boundary element at the web-flange junction can be designed with lower requirement.When the web was in compression,the specimen designed per ACI 318-14 showed the largest ductility,with an ultimate drift of 0.02 rad.This indicates that increase of the length of special boundary element and the volumetric ratio of boundary transverse reinforcement leads to enhancement of seismic performance of T-shaped walls.The other specimens had the same deformation capacity and failure mode.The analysis indicates that the performance of T-shaped walls might not be improved by increasing the length of special boundary element only.Sectional analysis using X-tract programs and finite element analysis(FEA)using Abaqus 6.10 program were conducted to investigate the seismic behavior and the method to calculate the strength capacity of T-shaped walls.Sectional analysis results indicate that the flexural strength capacity calculated based on the assumption that plane section remain plane after bending generally agree with the test results.However,the X-tract analysis can not capture the post-peak behavior of the T-shaped walls,as the strain measurement for the specimens indicates that strain profile at the base section of the T-shaped wall does not satisfy this assumption any more in the post-peak loading phase.Finite element analysis results indicate that the Abaqus model using solid element can track the bending performance behavior of the T-shaped wall specimens.Both the maximum strength and the compressive strain at the base section of the web wall at the failure state correlate with the test results.Additional parametric analysis indicates that increase of both the length of special boundary element of web edge and the volumetric ratio of boundary transverse reinforcement is necessary for improvement of seismic performance of T-shaped walls.Based on the experimental tests and numerical analysis the design recommendations are proposed for special boundary elements for T-shaped RC walls.