SEISMIC DAMAGE MODEL SUITABLE FOR STEEL REINFORCED HIGH STRENGTH AND HIGH PERFORMANCE CONCRETE COLUMNS

In order to preferably analyze damage mechanism of steel reinforced high strength and high performance concrete (SRHSHPC) columns subjected to seismic load, by comparing and analyzing the current several seismic damage models and based on hysteretic characteristics of SRHSHPC columns under low cyclic loading, it is established a seismic damage model suitable for SRHSHPC columns, which takes unloading stiffness degradation corresponding to maximum deformation and accumulated residual plastic deformation as damage parameters.Furthermore, based on existing experimental results, nonlinear regression analysis to damage model is made to determine related parameters of the model. Meanwhile, the influence of shear-span ratio, concrete strength and axialcompression ratio on the damage accumulation and development of SRHSHPC columns are analyzed. The results show that the damage of SRHSHPC columns develops faster with increasing of concrete strength and axial compression ratio during late loading stage; however, the ductility of SRHSHPC columns becomes better and the damage process becomes more smoothly with increasing of shear span ratio.