Estimation of axle loads by bridge-weigh-in-motion using strain measurement of transverse stiffeners

A method of estimating traffic loads on a highway by the deformation of a bridge is called bridge-weigh-in-motion (BWIM). The conventional BWIM is based on the strain measurement of main girders. To obtain supplemental information, strains of transverse stiffeners are also measured. Previously, it has been shown that the estimation of the truck loads by the strains of transverse stiffeners solely was possible. The method is competitive from the viewpoint of cost-effectiveness. Involving the integration of time-history response of strain, the method is called BWIM by Integration Method with Transverse Stiffeners. The present study tries to modify it so as to estimate the axle loads, concluding that it works fine for the axle load as well. Yet it is noticed that when two trucks run side by side, accuracy may be deteriorated. The way to improve the accuracy in such a case is also presented.