Volume 29, Issue 3 (May 2006)
An Improved Oedometer Apparatus to Measure Lateral Stress During Testing
Soils which have been subjected to complex geological stress histories (such as glaciation) exhibit incongruent geotechnical properties when tested in the oedometer. A new oedometer apparatus has been developed to permit measurement of anisotropic horizontal stress reactions during vertical loading. The objective of the apparatus is to assess how different geological stresses relate to present state properties. The apparatus has been tested using laboratory prepared samples of kaolin and thin tube core samples of Pot Clay from the north Netherlands. These results indicate that the new apparatus can measure isotropic and anisotropic lateral stresses with reasonable repeatability. Also, the orientation of maximum and minimum horizontal stresses can be calculated if oriented core samples are used. Results from the Pot Clay indicate anisotropic horizontal stresses which are related to the known glacial stress history.