Photogrammetric analysis of rubble mound breakwaters scale model tests

Abstract

The main goal of this paper is to develop a photogrammetric method in order to obtain a robust tool for damage assessment and quantification of rubble-mound armour layers during physical scale model tests. With the present work, an innovative approach based on a reduced number of digital photos is proposed to support the identification of affected areas. This work considers two simple digital photographs recording the instants before and after the completion of the physical test. Mathematical techniques were considered in the development of the procedures, enabling the tracking of image differences between photos. The procedures were developed using an open-source application, Scilab, nevertheless they are not platform dependent. The procedures developed enable the location and identity of eroded areas in the breakwater armour layer, as well as the possibility of quantifying them. This ability is confirmed through the calculation of correlation coefficients in each step of the search for the more damaged area. It is also possible to make an assessment of the movement of armour layer units.