Monitoring of the post-tensile structures camber using the terrestrial close-range photogrammetry

Post-Tensioned Structural Elements (PTSEs) are used in many modern constructions projects as a versatile form of the pre-stressed technique because of the efficiency of the durability properties and the highest resistance if compared with their counterparts. This paper presents an application of using digital measuring techniques in the field of deformation detection by using Digital Close Range Photogrammetry (DCRP), which is one of the most nowadays important sciences that are used in many engineering fields and applications. DCRP techniques have been developed by taking the advantage of the technological advances in the field of optics, laser devices, and the applied mathematical models of computer vision such as the Scale Invariant Feature Transform (SIFT) and the Direct Linear Transform (DLT). The scope of this paper is how to use the digital equipment to achieve the highest possible accuracy in a fraction of 1.00 mm of the PTSE camber monitoring through the commercial digital calibrated camera and Terrestrial Laser Scanner (TLS). The accuracy of the results of the DCRP technique has been proven by a laser total station. The final statistics indicate the deviation of the results compared to the coded designed models of the experimental PTSEs, deviations did not exceed 0.01 mm as a maximum difference.