Volume 31, Issue 6 (November 2008)
Characterization of Locked Sand from Northeastern Alberta
A comprehensive experimental investigation was carried out on a lower Cretaceous friable intact sand formation retrieved from northeastern Alberta. Index tests, microstructural observations, and mineralogical composition analyses were carried out to confirm that this formation fits into the locked sand category. The significance of the local strain measurements in revealing salient deformation characteristics of this formation was explored under uniaxial stress conditions. The test results showed that the characteristics of this formation are in keeping with the characteristics of locked sands. The intimacy between the grains stems from authigentic quartz creating interlocking rather than cementation. The results also revealed that local axial and lateral strain measurements are essential for proper behavioral characterization and failure mechanism interpretation of locked sands. The interlocked fabric results in an exceptionally high uniaxial strength and elastic axial stiffness. The disruption of the interlocking is achieved through the lateral expansion of the sample and formation of dilation bands.