Fatigue Assessment of Bridge Members Based on In-Service Stresses

摘要

This report summarizes research activities which are described in detail ininterim reports entitled 'Field Tests, Analyses, and Laboratory Tests' (Zwerneman et. at., 1996), and 'Data Acquisition System for Strain Measurements' (Zwerneman et al., 1997.) These two interim reports cover two distinct phases of the research project entitled 'Fatigue Assessment of Bridge Members Based on in-Service Stresses.' This research was undertaken to (1) evaluate the fatigue life of a specific highway bridge on which poor welds had been applied, and (2) construct a system for measurement of strains on an in-service highway bridge. The second part of the project includes demonstrating a procedure for using the measured strains to estimate remaining fatigue life and establish inspection intervals. The data acquisition system and evaluation procedures developed in this research project have the potential to provide benefits far above the cost of development and implementation. Cost savings result from improved fatigue life estimates, more accurate load ratings, and the ability to set intervals for fracture critical inspections on the basis of measured rather than computed stresses.