00390845

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http://onlinepubs.trb.org...trr/1984/950/950v1-008.pdf

https://scholar.google.co...yder&publication_year=1984

Important safety decisions are made each time a bridge is evaluated. Field inspections have concentrated on estimating deterioration and dimensions of load-carrying members. How to measure and use a load spectrum at the site is described. Information on truck loads, dynamic impact, and girder distribution can provide additional data for rating bridges. Five sites in Ohio are reported. In addition, almost 100 other instrumented bridges have been studied by a similar weigh-in-motion operation, which uses existing bridges to provide equivalent static weights of passing vehicles. Weight data are unbiased because the field operation is undetected by drivers. The measured bridge load spectra can replace conservative AASHTO rating recommendations for impact and girder distribution factors. In order to enhance this application a reliability or probabilistic approach incorporates the measured site load spectra in evaluating the bridge safety. Loading is modeled by random variables including truck weight, traffic volume (affecting multiple presence), axle spacings and loads, impact, girder distribution, and measured stresses. A load simulation forecasts the maximum response for periods corresponding to inspection intervals. The calculation incorporates uncertainties and provides a reliability measure for comparing bridge safety. Examples include ultimate strength and fatigue-limit states. Strategies are described for using the load spectra and the reliability model to develop load factors for rating, schedules for inspection intervals, posting control, and redundancy evaluation.

This paper appeared in Transportation Research Record Number 950, Volume 1, Second Bridge Engineering Conference conducted by the Transportation Research Board and the Federal Highway Administration, September 24-26, 1984. Publication of this paper sponsored by Committee on Structures Maintenance. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

01419841

pp 45-53

1984

Transportation Research Record

Bridge Engineering Conference, 2nd, 1984, Washington, DC, USA

03090036593

Print

Figures (14) ; References (14) ; Tables (6)

Bridges; Fatigue limit; Inspection; Load factor; Loads; Measuring instruments; Probability; Ratings; Redundancy; Reliability; Safety; Structural analysis; Structural mechanics; Ultimate strength; Uncertainty; Weigh in motion

Probabilistic analysis; Structural behavior

Bridges and other structures; Data and Information Technology; Design; Highways; Safety and Human Factors; I24: Design of Bridges and Retaining Walls

TRIS, TRB

Dec 30 1984 12:00AM