Study On Work Performance Evaluation Of In-service Hydraulic Steel Gate After Corroded Based On Reliability

As an important component of hydraulic structures,hydraulic steel gates can play a role in regulating flow and controlling water level,and have created huge economic benefits for hydraulic projects.Since the founding of the People’s Republic of China,with the rapid development of water conservancy and hydropower,the application of hydraulic steel gates has become more and more extensive,so the safety of gates has also attracted more and more attention.Corrosion is the most common damage phenomenon of hydraulic steel gates in use.It will weaken components,reduce structural strength and stiffness.Severe conditions may even threaten the safe operation of the gate.Therefore,it is particularly important and urgent to timely evaluate the safety of the working performance of the corroded hydraulic steel gate in service.Based on the reliability evaluation theory,combined with the example of the spillway cueved steel gate project of the Qiyi Reservoir in Jiangxi Province,a safety evaluation study on the working performance of the corroded steel gate was conducted through on-site inspection and finite element simulation of the steel gate corrosion.The research content is as follows:Summarize the existing data and documents,sort out and analyze the previous research results,systematically analyze the nature,mechanism and factors of corrosion of hydraulic steel gates on the basis of comprehensive consideration of all factors,the common methods of corrosion inspection and detection of hydraulic steel gates in service are elaborated in detail.According to the actual situation of the steel gate of Qiyi Reservoir,selected a suitable corrosion detection method,and obtained the data of the amount of corrosion of the curved steel gate,and carried out a preliminary analysis of the actual corrosion of the steel gateUsing the finite element software of Ansys,established the finite element model of the curved steel gate of Qiyi Reservoir with and without corrosion,and the change of static and dynamic performance of the curved steel gate before and after corrosion was analyzed.In order to study the influence of different corrosion locations and different degrees of corrosion on the static and dynamic performance of steel gate members,simulated different corrosion depths of each member based on the actual corrosion model.It is shown that corrosion has a greater impact on the strength of the gate,a smaller impact on the stiffness,and a relatively small impact on the natural frequency and mode shape of the gate by comparing the static and dynamic calculation results of the gate under various corrosion states and working conditions.By summarizing and analyzing the influence of corrosion on the stress and deformation of the gate,the limit state equation of each failure mode is established by using the stress coefficient method,and used the JC method to calculate the reliable index of the gate to conduct a safety evaluation of the gate’s working performance.The calculated evaluation results are compared with the actual safety appraisal and evaluation results to verify the rationality of the results.At the same time,it also verifies the feasibility and accuracy of using the reliability theory to evaluate the working performance of corroded hydraulic steel gates in service,and provides a new way for the safety evaluation of the working performance of hydraulic structures.