Plastic hinge length of FRP strengthened reinforced concrete columns subjected to both far-fault and near-fault ground motions

In a strong earthquake, an rc column develops plastic deformations in regions often definedas plastic hinge regions. the formation of a plastic hinge in an rc column in these regions dependson the characteristics of the earthquakes as well as on the column details. recordings from recentearthquakes have demonstrated that ground motions in near field to a rupturing fault can contain alarge energy. this energy can cause considerable damage during an earthquake. therefore, many recentlydesigned and constructed buildings may require strengthening in order to perform well when subjectedto near-fault earthquakes. fiber reinforced polymers are considered to be a viable strengthening methoddue to their relatively easy and quick installation. in this paper, 1350 inelastic time-history analyseshave been performed to predict the nonlinear behavior of frp strengthened rc columns under bothfar-fault and near-fault earthquakes. the effects of axial load, height-depth ratio and the amount oflongitudinal reinforcement, as well as different characteristics of earthquakes, are evaluated and theresults are compared with the corresponding experimental data. based on the results, simple expressionsare proposed that can be used to estimate plastic hinge length of frp strengthened rc columns subjectedto both far- and near-fault earthquakes.