Research On High Arch Dam Structural Damage Identification Based On Model Updating Technique

Research on the health monitoring is currently focus of the major hydraulic structure. Response information of high arch dam structure can be used to analyze the variation of the stiffness and bearing capacity, and then identify its structure damage. This method has great engineering values.The aim of the dissertation is to establish the damage evaluation method for the high arch dam. The quasi-steady-state temperature field of arch dam is given according to references. The impact of reservoir water on arch dam is investigated. Then three-dimensional finite element model of the Ertan arch dam is established which is considered effect of temperature and coupling effect between reservoir water and arch dam. The response surface method based on the static and dynamic responses data of high arch dam is developed to update the finite element model, and then, the damage location and extent of dam can be indicated. Above results can take as the necessary theoretical base of online detection and damage identification.(1) The prototype structural parameters, water level and temperature of arch dam are collected for suitable finite element model of high arch dam. The static and dynamic responses under the condition of reservoir water pressure, weight and temperature loads are analyzed. By comparing the calculated results, reliability of model can be validated and the basis for the division of the sub-regions of the dam is provided.(2) The reduction of elastic modulus in the sub-regions is used to simulate the structural damage. Response surface equation is formulated to fit the nonlinear relationship between the elastic modulus of sub-regions and the responses of overall structure. According to the accuracy of response surface model and the sensitivity of the response data, the data point of response can be selected optimally and the response surface model of corresponding response data is established.(3) Based on the optimal measured point, the genetic algorithm based on response surface model of measurement data is adopted to identify high dam structure damage. The affect of noise is regarded simultaneously. The numerical simulation indicates the feasibility of the proposed method.(4) Combining static and dynamic measurement results of damage detection, the data fusion technique is adopted based on D-S evidence theory, in order to improve further the reliability of the recognition result.By the results, the accuracy of response surface model is high. The model updating technique based on the response surface model is successfully used to identify the damage in high arch dam.