Deformation measurement of bridge structures using close-range photogrammetry: Fid-Bau Portal

Deformation measurement of bridge structures using close-range photogrammetry

Jauregui, D.V. / White, K.R. / Woodward, C.B. / Leitch, K.R.

This paper reports an the use of digital close-range terrestrial photogrammetry (DCRTP) for bridge deflection measurement. Photogrammetric procedures are discussed by analysis of two full-scale bridges. The first bridge is a prestressed concrete girder bridge. Measurements were made during the construction process to determine the camber of the girders before casting of the deck, the dead load defection due to the casting of the deck, and the final deflection after casting of the barrier rails. Close agreement of DCRTP analysis with level rod and total station data was achieved The second bridge is a 64-year-old slab-on-girder simple supported bridge, built without shear connectors between the deck and steel wide flange girders. The deflection of the steel bridge was evaluated under live loading by two dump trucks. The DCRTP analysis was able not only to estimate the relatively small deflections under loading but also provided an insight into the behaviour of the bridge such as the level of composite action between the girders and the deck. Photogrammetic analyses compared favourably with level rod readings. With the advent of ever more powerful and inexpensive digital cameras and microcomputers, the cost of a DCRTP system continues to fall. Thus, it is anticipated that DCRTP will provide highway agencies with a cost-effective alternative to high cost systems with the potential for several types of measurements in bridge applications.