Research On Seismic Shear Capacity Of Reinforced Concrete Piers Within Plastic Hinge Regions

The deformation limits of columns designed following current codes of many countries dominated by concrete crushing or longitudimal renforcement buckling within yield hinge reions near columns ends,rathe than shear failure.But until now,there are many different viewpoints for the calculation method of the shear capability,and the theory or formulations for the shear strength specified in the specifications of different countries are not same. So,the shear performance of the bridge pier under the seismic effect is studied in this paper in order to provide theoretical basic and reference of calculation.There are four kinds of seismic failure modes of piers:Flexural failure type,Shifting type from flexural damage to shear failure,shear failure type. Real response to the true shear capacity of bridge piers,this test belongs to destructive testing. The calculation of shear capacity outside the plastic zone in the Pier,the concrete shear capacity has not been reduced, shear capacity of pier without reference to seismic formula.(eg:In China,we can calculation with the Design Code of Concrete Structures. In checking shear capacity of Pier Under seismic action,the destruction form of Pier must be Shifting type from flexural damage to shear failure,it not only meet the calculation of shear capacity outside the plastic zone in the pier,but also to meet the failure modes of piers is shear failure type.In this paper, Four set of piers with the same reinforcement ratio and the different height,are designed for the pseudo-static loading test. Through the analysis of test results we can know the failure modes of pier and the change in stress and strain of reinforcement and the overall deformation of the piers. We calculated the shear capacity of piers by the formulas given by Priestley,ATC-32 code ,Caltrans code, Japanese code and Chinese code in order to compare the applicability of these formulas and the failure modes of piers and axial compression ratio impact on the shear capacity of the pier...