RESEARCH ON REALIZATION OF SEISMIC DUCTILITY BY HIGH STRENGTHREBAR FOR RAILWAY PIERS WITH LOW REINFORCEMENT RATIOS

The railway bridge piers with low reinforcement ratios are still widely used in our country，which have poor deformation capacity and brittle failure mode under earthquake． In order to improve the seismic performance of such a kind of piers，the idea of using high strength rebar to realize seismic ductility for piers with low reinforcement ratios is put forward． A HRBF500 reinforced pier specimen with low reinforcement ratio was tested under low-cycle loading． The failure mode，hysteretic characteristics，stiffness degradation，energy dissipation and ductility of the specimen were studied． The results indicate that the failure pattern of the specimen is ductile failure． Furthermore，the realization mechanism of seismic ductility by high strength rebar for piers with low reinforcement ratios is further analyzed．