Study On The Uncertainty Of Cable Force Dynamics Test For Stay Cable

The accuracy of the cable force test is one of the most concerned issues in the construction and operation phase of cable-stayed bridges.At present,our research group has initially established the cable force measurement system.On this basis,it is an important part of perfecting the cable force measurement system to study the engineering application of the cable force measurement method under the real bridge operation conditions and to enable the method to trace the source value in the engineering application scenario.This paper studies the "Engineering Application" sub-item of the " Research Cable force Measurement Standard " of Sichuan Provincial Transportation Science and Technology Project.From the perspective of uncertainty,this paper had researched the existing bridge application examples that used cable force dynamics test method,and the difference and relationship between the error theory and the uncertainty theory under the application conditions of the engineering bridge are established.The numerical analysis software was used to establish the numerical model of stay cable and the uncertainty evaluation results were used to analyze the influence of the cable force test model on the cable force test results.On this basis,the influencing factors of the uncertainty of the cable force measurement results are analyzed,and the cable force uncertainty under the influence of the influencing factors is determined.Finally,the cable tension test is designed and implemented and the uncertainty of the test results is carried out.The main work is as follows:(1)Cable force measurement technology,cable force measurement practice status and accuracy of measurement results are investigated of the literature.Research on three types of cable force calculation methods,such as cable force analytical method,cable force approximate solution method and cable force numerical solution method.Inductive Cable force loop or pressure gauge gives reference values and no reference values for two types bridge application of cable force dynamic measurement method.Based on this,analysis error theory develops into three stages of uncertainty theory,and combined with the theoretical analysis of cable force measurement method,the technical route of uncertainty analysis of cable force measurement method is proposed.(2)Theoretical analysis of uncertainty evaluation of cable force measurement method and case analysis of bridge application.Under the framework of uncertainty theory,the cable force is defined and the calibrated pressure tester is used as the standard instrument to measure the cable force.The influencing factors of the cable force measurement result and the cable force uncertainty measurement method are analyzed.Combined with the data in the reference value engineering application example,the error results theory and the uncertainty theory are used to calculate the test results.Combined with the example data without reference values,the influence of the cable influence factors on the measurement results is calculated.(3)The standard method for measuring the measured and measured results of the cable force measurement method under the real bridge operation scene by cable force dynamics test is studied.The finite element software is used to establish the real bridge cable model,and the modal frequency and cable structure parameters are substituted into the adaptive Monte Carlo method for uncertainty evaluation.According to the calculation results,the influence of the cable force measurement model and the model parameters on the cable force test results is analyzed.On this basis,the field measurement of the cable is designed and implemented,and used the uncertainty evaluation method for cable force dynamic test to calculates the two-year(2016 and 2018)test data of three typical cables of a cable-stayed bridge in Chongqing are standardized by the uncertainty evaluation method of cable force dynamics test.