Study on effective stiffness of circular hollow reinforced concrete piers under seismic load
Based on the quasi-static test data of 52 circular hollow piers and the three-component yield displacement model,the applicability of existing effective stiffness formulas for circular hollow piers was analyzed,the main influencing factors of the effective stiffness of circular hollow piers were discussed.The effective stiffness calculation formula for circular hollow piers was calibrated by using axial compression ratio,longitudinal reinforcement ratio,shear span ratio,and hollow ratio as the control factors,and the validity of proposed formula was verified by simulating the hysteresis curves of full-scale and scale circular hollow piers.The results show that most existing effective stiffness formulas significantly overestimate the average of effective stiffness of circular hollow piers,with large coefficient of variation.The effective stiffness of circular hollow pier increases with the increase of axial compression ratio,longitudinal reinforcement ratio and aspect ratio,and decreases with the increase of hollow ratio.The coupling effect of aspect ratio and hollow ratio can be considered by the equivalent aspect ratio,and the effective stiffness increases with the equivalent aspect ratio.The mean value and coefficient of variation for the ratio of the calculated effective stiffness value given by the proposed formula to the test value are 1.04 and 0.21,respectively.Compared with existing effective stiffness formulas,the supposed formula provides higher accuracy and greatly reduces the degree and possibility of possible overestimation.The effective stiffness calculated by the suggested formula can accurately simulate the hysteretic curve,the yield stiffness,and the loading and unloading stiffness of circular hollow piers.
万方数据
维普
