Displacement field measurement of stacked geotextile tubes by digital image correlation

Displacements often need to be measured to evaluate the stability of earth dams. Various instruments for measuring the displacement exist, but most contacting position sensors can measure the displacement only at a certain position. Digital image correlation is a promising technique for measuring a displacement field through a camera without any contact with the measurement points. In this study, variations in the displacement fields of stacked geotextile tubes with the water level are evaluated using digital image correlation. Experimental results show that the vertical and horizontal displacements of the bottom layers are larger than the top layers with an increased water level. The top layer mainly moves backward and then moves upward and forward. In contrast, the bottom layer consistently moves upward and forward after an initial downward and backward movement. Thus, the digital image correlation method suggested in this study may be effectively used to evaluate the behavior of a temporary dam structured with geotextile tubes.