Study of the Strain Response of Asphalt Pavements on Orthotropic Steel Bridge Decks through Field Testing and Numerical Simulation

摘要

A composite structural system consisting of an orthotropic steel bridge deck,waterproof prime, binding course, and wearing surface is complicated. To simplifythe analysis of such systems, general elastic and continuous structure theory isapplied to the asphalt pavement on steel bridge decks to determine the magnitudeof the strain. Large differences in mechanical results have been previouslyobtained in assessments of steel bridge deck pavements. Few studies have focusedon the mechanical state and time-dependent response of a realistic steel bridgedeck wearing surface because of the difficulty of measuring the strain of thepavement on a steel deck of a long-span bridge that is in service. This studyperformed static and dynamic loading tests on an actual long-span steel bridge andanalyzed the characteristics of the time-dependent strain response of the bridgedeck wearing surface. The results demonstrate that the asphalt wearing surfaceexhibited significant loading time and rate-dependent characteristics under bothstatic and dynamic loading conditions. The test analysis results also revealed thatthe axle load, vehicle speed, and longitudinal slope of the bridge had significanteffects on the mechanical responses of the bridge deck wearing surface. Based ona comparison between the finite element numerical simulation results and themeasurements obtained from testing the actual bridge, the magnitudes of themechanical strain responses of the wearing surface on a steel bridge deck underthe dynamic wheel load of a vehicle were analyzed assuming that the wearing surface is elastic and that the elastic modulus can be determined from afour-point bending test. However, the cumulative effect of plastic deformationmust be considered when analyzing the fatigue damage of a permanent wearingsurface.