Applications of photogrammetry to structural assessment

Photogrammetry is a method developed in the early XIXth century. Nowadays, with digital photography associated to the development of image processing and its automation, this technique has become appealing in different fields of application. In this paper, the authors analysed the current feasibility and advantages of using photogrammetry in structural monitoring. First, the method was calibrated using two laboratorial tests: (1) monitoring of failure and creep tests of long-span reinforced concrete beams; and (2) monitoring of steel beam-to-column connections. Then, the method was tested on site, namely, in monitoring the deformations of a footbridge subjected to different loading situations. It was concluded that photogrammetry can be used in structural monitoring with accuracy and exhibiting additional advantages in relation to traditional methods, namely: (1) an almost unlimited number of measuring points can be considered and automatically processed; and (2) hardware is unnecessary and, therefore, it can be used under almost any situation where traditional methods cannot be employed.