WEIGH IN-MOTION AND STRUCTURAL DEFLECTION BASED MECHANISTIC ESAL FACTORS FOR URBAN PAVEMENT ASSET MANAGEMENT

摘要

Equivalent Single Axle Loads (ESALs) have been the standard measure of traffic loadings usedin new highway engineering design and life cycle performance prediction. However, truck andbus traffic in urban centre field state conditions often pose a higher probability for overloadingrelative highway applications. In addition, many urban pavement systems are not constructed tothe same structural standard as typical AASHTO type primary highway pavement systems interms of layer thicknesses as well as cross sectional drainage. This research employed amechanistic-based road structural response methodology to calculate ESALs from commercialtruck and bus loadings on various classes of urban streets based on actual primary road responseimpact load spectra.This project integrated weigh-in-motion (WIM) and pavement deflection measures to quantifyCity of Saskatoon urban traffic load spectra, and the impact of this load spectra on typical inserviceurban streets in typical field state conditions.Based on measured pavement primary responses across City of Saskatoon road structures and themeasured urban load spectra, this research found that conventional Equivalent single Axle loadsmay significantly underestimate the impact of truck loadings on in-service urban roads. Thisresearch also showed that based on primary deflection response, multiplying factors approaching40 may be required to calculate load equivalencies. Therefore, the structural design, transitrouting, and construction bypass routing should incorporate the actual detrimental impact ofspecific vehicle types and loadings on the in-situ structural condition of the in-service roadstructure.