An Optical Technique for Investigating Soil Displacement Patterns

An optical, nonintrusive technique for measuring soil deformation in three-dimensional laboratory scale tests is described. The technique combines the use of a video camera capable of recording the movement of targets to a high resolution, and a transparent porous material possessing geotechnical properties similar to natural clay. The technique is demonstrated in a model test conducted to measure soil deformation patterns around penetrometers. The displacement measurements compare well with results from other published tests and indicate that the technique can provide better resolution than has been previously achieved in similar laboratory tests.