Evaluation of a Load Cell-Based Bridge Weigh-in-Motion System

Abstract

A bridge weigh-in-motion (B-WIM) system utilizes an instrumented bridge to obtain the axle information (weights, number, and spacings) and weight information (axle and gross) of vehicles that cross the structure. Traditional B-WIM systems are based on strain measurements and utilize the Moses algorithm. A wide array of additional measurement types and algorithms have been explored by researchers. However, load cells have rarely been used for B-WIM systems. This paper proposes a B-WIM system using load cells to measure the reaction force at the supports. Full-scale field tests were conducted on a slab-beam bridge instrumented with load cells to evaluate the effectiveness and accuracy of the proposed B-WIM system. The second derivative of the load cell data was used to accurately find the axle information of the trucks. Two weight calculation methods, the reaction force method and the area method, were utilized with the field test data. The results were then quantitatively compared. Overall, load cells show promise for use in future B-WIM systems given the reasonable accuracies determined in this study.