DETERMINATION OF DISPLACEMENTS IN LOAD TESTS WITH DIGITAL MULTIMEDIA PHOTOGRAMMETRY

This paper describes the use of multimedia photogrammetry for determine of deflection behavior of buried flexible pipe 312 mm diameter is placed in highly strengthened steel box under load. 20 mm thick transparent Plexiglas was used in front face of the box. An on-line configuration of three CCD cameras was established to measure targets subject to positional displacement. The entire measurement process was consist of five steps: calibration of camera system, acquisition of multi-image sets, establishment of corresponding points in the images, computation of their 3-D coordinates, acquisition of images after each load application and computation of 3-D coordinates. The algorithm proposed by Maas (1995) was used in order to solve problems of multimedia photogrammetry. For this algorithm is used, the XY plane of coordinate system should be chosen parallel with the plane interface air/glass. Sub-millimeter object point precision has been achieved in all three coordinate dimensions for each measurement epochs.