Volume 39, Issue 5 (September 2011)
Optical Measurement of Sand Deformation around a Laterally Loaded Pile
A sand displacement field around a laterally loaded pile is measured using an image processing technique called digital image correlation. An optical system consisting of a camera, a loading frame, and a computer is developed to capture soil movement during laterally loading the pile. Two images, before and after a deformation, are used to calculate the soil displacement field. Two kinds of piles are used in the tests: one squared-section pile and the other a circular one. Dry loose sand samples are used to simplify the problem. The displacement and strain fields obtained in this study are similar to the ones reported from the field. A trapezoidal strain wedge is measured in sand in front of the laterally loaded pile. The strain wedge develops from the pile edges. The failure planes form an angle with the horizontal, which varies between approximately two-thirds of the frictional angle of soil for the square pile and three-fourths for the circular pile.