2023 Volume 79 Issue 15 Article ID: 22-15051
The bridge deflection when passing a train, which is a typical index expressing bridge performance, requires a great deal of labor and cost to measure. In this study, a drive-by quasi-static bridge deflection estimation method based on track vertical irregularities measured on a traveling vehicle is developed, as a more efficient measurement method. The followings were clarified by theoretical analysis reflecting the actual installation position of the inertial mid-chord offset track irregularity measuring devices; the difference in track irregularities measured by the first and last vehicles is proportional to the quasi-static bridge deflection, the maximum value of the bridge deflection can be estimated by multiplying the maximum difference between the track irregularities of the first and last vehicles by the conversion coefficient, and the sensitivity changes depending on the measurement position of the track irregularities. Finally, it was demonstrated that the maximum value of the bridge deflection of the two bridges estimated by the proposed method from the track irregularities measured on the actual line is in good agreement with the result of the on-site bridge deflection measurement within an error of 10%.
