Seismic Damage Model of RC Pier Repaired with CFRP Considering Initial Damage
In order to study the damage evolution law of damaged reinforced concrete(RC)structures repaired with carbon fiber reinforced plastics(CFRP)under earthquake action and accurately quantify the damage status of repaired structures,a quasi-static test of 10 circular RC piers was carried out,eight of which were repaired by different CFRP reinforcement methods.The test results were studied based on eight typical earthquake damage models,and a two-parameter seismic damage model for RC piers repaired with CFRP was established,in which the reduction coefficient of material properties was introduced to analyze the initial damage to the structure.The damage degree of RC structures was quantified according to the experimental phenomenon and the improved damage model.The results show that when the damage index of the repaired pier is calculated by using the typical earthquake damage model,the damage index of the damaged specimens is generally too large,and the variation of the damage index of the same pier model is quite different.The development trend of the damage index is not consistent with the experimental phenomenon.Based on the nonlinear regression analysis of the specimen parameters,the empirical expressions of the combination coefficients and design parameters are obtained.The proposed damage model can better simulate the seismic damage evolution process of piers repaired with CFRP.Five grades of RC structure damage are defined,and the damage index limit value of the five grades is given.For moderately damaged pier structures(0.3<D≤0.6,D is the damage index),it is recommended to use pre-stressed CFRP reinforcement after repairing and leveling the structural surface to achieve better results.
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维普
