A Parameter Estimation Method for Bridges Based on Field Measured Influence Lines

A method for bridge structural parameter identification using field measured static influence lines with respect to various types of measurement is presented. Static test data on displacement, tilts and strains are quantified by means of influence lines to estimate global and local, sensitive and insensitive parameters of any model form of structure. A quadratic performance error function to be minimized was established with interpolation or fitting procedures. An analytical example of a simply supported beam is employed for demonstration purpose. A numerical example of plane stress is presented and local and insensitive parameters are successfully and accurately estimated. Results of the example suggest that despite no competitive advantage in estimating the sensitive parameters with integrative measurement, it is an essential point to the successful identification of insensitive parameters by making a judicious selection of integrative measurement.