Research On Safety Evaluation And Operation And Maintenance Countermeasure Of A Spillway Bridge Based On Static And Dynamic Load Test

In recent years,with the rapid development of Chinese economy,the number of bridges built in China has increased each year,and the scale of bridges has become larger and larger,but the collapse of bridge structures has frequently occurred,and People put forward higher requirements for the safety of bridge structure.The static and dynamic load tests of bridge structures are one of the main components of bridge structure safety assessment,so it is of great significance to conduct in-depth research on them.Bridge static load and dynamic load test is an important method to verify the bearing capacity and overall performance of the bridge structure,and it is also an important method to assess the technical condition of the bridge structure.This paper first introduces the finite element method and its application in the theoretical analysis of static and dynamic loads on bridge structures,and then details the contents and methods of field tests for bridge structures in static and dynamic loads.Finally,the factors affecting the static and dynamic load tests of bridge structures are analyzed.The work done in this article is as follows:(1)The finite element method and its application in static and dynamic load tests of bridge structures are introduced;the free vibration theory of bridge structures is introduced;the test content,test process and data analysis methods of continuous bridge static and dynamic load tests are introduced in detail;(2)Static and dynamic tests were performed on an actual bridge.The tests show that:(1)the cross-section dimensions,concrete strength grades,and concrete layer thickness of the main structural members of the bridge meet the requirements of relevant codes,and no obvious cracks and deformations are found;(2)Under the test static load,the deflection verification ratio,strain verification ratio,relativeresidual displacement and relative residual strain of each measuring point of the bridge meet the requirements of relevant specifications.No observable cracks are found in the control section and its vicinity before,after and during the test,and the bearing capacity of the bridge meets the requirements;(3)Under dynamic excitation,the bridge structure has good rigidity and has a certain energy consumption capacity,and its integrity and flatness of the bridge deck are good.(3)The influencing factors of the static and dynamic load tests of the bridge structure are analyzed.Guardrails and bridge deck paving can reduce the stress and deflection of the corresponding parts and increase the verification ratio.As the vehicle speed increases,the impact coefficient of the bridge structure also increases.The worse the flatness of the bridge deck is,the greater the impact coefficient of the bridge structure is.The research in this paper can provide a reference for the theoretical research and engineering practice of similar projects in the future.