Assessment Method For Railway Piers Based On Dynamic Response Sensitivity Analysis

Currently, the researches of dynamic damage identification mainly focus on superstructures of bridges, while little attention has been paid to the evaluation of bridge substructures. On the basis of existing researches, a condition assessment method for railway piers based on dynamic response sensitivity analysis is proposed. The main work and conclusion are as follows:(1)State-of-arts of current damage detection methods are discussed and the advantages and disadvantages of them are compared. The development trend and difficulties in damage evaluation area are concluded.(2)Model updating method based on sensitivity analysis is discussed in detail. The damage identification theory based on sensitivity analysis is elaborated and the solution of sensitivity equations is erected.(3)The finite element model of piers considering beam quality and constraints of foundation is established. Both the increase and decrease of pier stiffness are analyzed. The results both the location and damage extent of pier body can be grasped by the proposed damage identification method.(4)Damage evaluation results with different measurement point locations and excitation point locations are compared and their influence is analyzed. In the end, the optimum arrangement of measurement points and excitation points are suggested.(5)The stiffness of the foundation after damage or reinforcement is identified by the proposed condition assessment method. The evaluation results agree well with the assumed damage, which proves that this method is also applicable to evaluation of working states of bridge foundations.