Structural Modeling, Instrumentation, and Model Calibration of the Maurice J. Tobin Memorial Bridge

摘要

Structural Health Monitoring technologies have attracted increasing interest in the past decade,although qualitative and non-continuous methods of structural evaluation have been in use longbefore the 21st century. Objective systems of condition assessment could provide continuousfeedback relating to bridge performance between biennial visual inspections. This could beachieved by developing a structural health monitoring system using a combination ofinstrumentation, remote data management and reporting, structural analysis modeling, and modelupdating based on measured structural response. This article describes activities in developingstructural models, installing a system of instrumentation, and model verification on the MauriceJ. Tobin Memorial Bridge in Boston, Massachusetts.The Tobin Bridge consist The Little Mystic Truss, The Big Mystic Truss, a toll plaza andmultiple shorter steel beam spans. The Little Mystic Truss is the focus of this paper. To enhancethe current bridge management system, an instrumentation plan was developed and deployed onthe Little Mystic to calibrate a structural model. A set of detailed finite element models weredeveloped to determine the impact of modeling assumptions, including truss behavior,connection stiffness and boundary conditions. A load test was performed to collect strain data formodel updating. Manual model refinements improved the correlation between model predictionsand collected strain data. This paper presents a collaborative research project partially fundedby the Massachusetts Port Authority and the Partnerships for Innovation Program at theNational Science Foundation to develop a framework for bridge condition assessmentintegrating instrumentation and structural modeling.