Damage Identification Research Of High Arch Dam Structural After Earthquake

The Western China has abundant water resources and complicated topography. In order to achieve the strategy of transmitting electricity from West to East, a lot of hydraulic structures have been built up in recent years. High arch dam structures have been widely used due to the good capability in load capacity, less dosage of concrete and good self-adjustment ability.Because of the hydraulic structures is vulnerable to the earthquake, the seismic safety evaluation of high arch dam has received extensive attention. For improving seismic safety of high arch dam structure, this dissertation studied the damage identification of high arch dam after earthquake.1. The prototype structural parameters are collected based on the engineering background of the ertan high arch dam. The model of high arch dam is set up by the finite element analysis software, and the feasibility and effectiveness of the model is proved by comparing the modal responses of finite element model with the relevant reference about ertan high arch dam.2. The damage of concrete is a cumulative process of plasticity. Simulating nonlinear behavior of concrete can truly reflect the damage of concrete structures through the plasticity constitutive model. By analyzing the finite element plasticity damage model of concrete and simulating the damage of high arch dam under the earthquake duration effects, this dissertation analyzed damage rules and seismic weak areas, and proved the regularity of damage model of high arch dam structure under earthquake.3. Each area damage degree of high arch dam caused by earthquake was simulated by reducing structural elastic modulus(damage parameter) in this dissertation. The identification of structure parameters is classical inverse problem, so it hs strong unsuitability. To reduce the unsuitability of inversion calculation and improve accuracy of structural damage identification, this dissertation classified the damage modes of high arch dam under the earthquake by the regular pattern of damage, determined the relation and variable range of damage parameters, introduced a prior information for the damage detection work,4. According to the modal characteristics of the damage modes, the screening method of the measured modal data was established to determine the possible damage modes of the structures. By analyzing the possible damage model and combining the response surface model correction technology with the genetic algorithm, this dissertation identified damage areas and damage degrees of the high arch dam structure. In order to improve the ill posedness of algorithm, Tikhonov regularization parameters are increased to optimize the algorithm to improve robustness of the algorithm.