Experimental Study On Seismic Performance Of Steel Reinforced Concrete Short-pier Shear Wall With Built-in Prestressed Bracing Or Horizontal Rod

In this paper,a new type of SRC short-pier shear wall which built-in prestressed bracing or horizontal rod,will be proposed in order to improve the bearing capacity and seismic performance.Some experimental study will be taken to investigate the affects of prestressing-size or prestressing bar configuration on seismic performance of structures.The results will lay the theoretical foundation and scientific basis of prestressed technology in the short-pier shear wall structure.This article designs and produces fives SRC short-pier shear walls in 1/2 scale which have the same dimensions,reinforcement forms and axial compression ratio.Selecte finish rolling rebar as the prestressed material in this experiment and the variables include prestressing-size and prestressing bar arrangement,each of them has two levels.Choose 0.6 fpyk and 0.7 fpyk as the control stress for prestressing,while X-shaped and horizontal as the arrangement of prestressing steel.Through the experiment,the specimens were observed and analyzed by the failure process and patterns,the change process of prestressing-size has record,the load displacement stagnates time of curve having measure.Based on these test data,bearing capacity,stiffness and its degradation,ductility and energy dissipation capacity and prestressing action mechanism have been investigated.Main conclusions can be drawn as follows:1.Set prestressed bracing have less impact on changing the failure processs and damage character,but it could significantly delay the conduct of wall cracks and inhibit the development of cracks.With the increase of presstressing-size,the effect becomes more obvious.2.Different arrangement and prestress-size have different effects on cracking load,yield load and bearing capacity of wall.When set to X-shaped bracing,cracking load,yield load and bearing capacity have increased,but the yield load and carrying capacity decrease with the increase of prestress-size;when set to the horizontal rod,cracking load become lower,the yield load and carrying capacity have small changes.3.There are large differences in the effects of different arrangement and prestress-size on the seismic performance of wall.When set to X-shaped bracing,stiffness,ductility and energy dissipation capacity significantly improved,but the ductility decreases with the increase of prestress-size;when set to the horizontal rod,energy dissipation capacity of later stage has improved,but ductility become worse.4.Prestresse value fluctuates with the positive and negative changes in loading process.Prestressing loss increased gradually,and the rate is fast at the early stage and late stage is slow.5.Three calculation models are established,the results of two models obtained from the formulas and those from experiment are in good agreement.