Damage quantification and monitoring in masonry monuments through digital photogrammetry

The measurement and monitoring of structural damages in masonry monuments is an important task in the field of conservation and restoration of architectonic heritage. Traditional surveying devices provide punctual measurements of the damage size and usually are contact-demanding, being an important limitation since risky systems are needed when structural problems appear in no accessible locations. In this field close-range Photogrammetry depict a valuable option. In this paper the dimensional analysis and temporal monitoring of crack is accomplished. Accurate 3D clouds of points defining the crack boundary are obtained in different dates. A quantification of the crack size in each date is obtained by shape parameters. This procedure allows detecting any displacement in ashlars and obtaining a feasible knowledge of the crack growth even when no fixed references are available to align 3D models obtained in different times.