Volume 7, Issue 2 (June 1984)
Determination of Local Displacements on Soil Samples
A description is given of two types of laboratory instrumentation suitable for monitoring deformations locally over a central portion of a soil sample. Using this instrumentation the problems caused by apparatus compliance, by bedding of the end caps, and by imposition of zero lateral movement at the ends of the sample (such as in conventional cylindrical tests) are avoided. In this paper the instruments are used to determine the three principal strains in a hollow cylindrical sample, which is subject to different axial, horizontal shear, radial, and circumferential stresses.