Using multi-response parameter estimation for structural condition and risk assessment of in-service bridges

Structural parameter estimation has great potential for the purpose of structural condition assessment of in-service structures. The information gained through structural parameter estimation can be used to develop a load rating system and other risk assessment tools for in-service bridges. Simultaneous use of static and modal measurements or “multi-response” parameter estimation is used in this paper. The ability to combine different sets of measured data for a single structural parameter estimation scenario, allows the user to take advantage of each piece of information available to them through the recent advances in multiresponse parameter estimation. An error function normalization technique is also used to facilitate effective multi-response parameter estimation. This normalization technique can alleviate some of the numerical issues encountered during the structural parameter estimation procedure without degrading the integrity of the parameter estimation procedure or the validity of non-destructive test data. A bridge bent example is presented to illustrate the application of multi-response parameter estimation for structural condition assessment, model updating, and to develop a load rating system for in-service bridges. The combination of normalization and multi-response parameter estimation improves the robustness of the parameter estimation for use as a component in a structural condition assessment and risk assessment program.