Damage index analysis of prefabricated segmental bridge columns under cyclic loading

摘要

The damage index is usually applied to evaluate the damage states of bridge structures, which is the basis of structural fragility study. The present study investigates the seismic damage index of the prefabricated segmental bridge columns (PSBC) under cyclic loading by theoretical and numerical analysis. Based on the previous pseudo-static experiments, different damage states characteristics of the monolithic cast-in-place bridge columns (MCBC) and the PSBC are discussed and analyzed to propose the limit-state capacities for each damage state of the PSBC. The limit-state capacities include four parameters: compressive strain of concrete, the tensile strain of steel, the prestress level and the residual displacement. Two finite element models of the PSBC are developed by OpenSees to carry on numerical analysis. Using the numerical results, the damage indexes for the PSBCs are obtained based on the limit-state capacities obtained above. The results indicate that the numerical results show good agreement with the experimental results of the bridge columns. The damage index formula of the PSBC, derived in this study, is reasonable and can be further applied. The maximum error between the proposed damage index and that obtained in the verified case is 20.3%. The proposed method in this paper for developing the damage index of the PSBC can be used in the seismic vulnerability analysis assessment of the bridge structures with prefabricated segmental columns.