BWIM BY TRANSVERSE STIFFENERS OF STEEL I-GIRDER BRIDGE

Abstract

  For constructing a maintenance scheme of an existing bridge, the methods for estimating the weights of heavy trucks on highways are needed, and Bridge-Weigh-In-Motion (BWIM) has attracted many researchers. A standard BWIM is based on the measurements of strains at lower flanges and transverse stiffeners of main girders. In the present study, BWIM only by the strains at transverse stiffeners, which is therefore simple and more economical, is proposed. It is based on the integral BWIM and is named "BWIM by Integration Method with Transverse Stiffeners (BWIM-IT)". Its accuracy is investigated using the data of field test. In most cases, the accuracy is satisfactory from a practical viewpoint, except when trucks run in parallel in two lanes in the down-lane bridge. The problem is found attributable to a cross girder and/or a cross frame distributing loads between main girders. It is then demonstrated that the accuracy can be improved if the transverse stiffeners on which the influence of truck loads in the adjacent lane is small are used. The study then concludes that the proposed BWIM-IT can achieve the accuracy as good as the standard BWIM, provided that appropriate transverse stiffeners are utilized.