Applying Moiré photography to internal load distribution in arches and walls

In order to carry out the modelling of arch bridges in three dimensions, the load-bearing areas within the arch barrel must be identified. It is shown how the Moire photography process provides a suitable technique for the recording of displacements over a whole surface. The article describes how small scale wooden walls having different loads and loading positions were tested and analysed. Edge effects and stiff abutments also influence the distribution pattern and induce stress concentrations, which need to be considered when modelling arch bridges.