Intrinsic Failure and Cracking of Clay
- R. S. Murray and
- J. P. Quirk
Cracks play a major role in determining the strength and fluid transmission properties of clay soil. This report, which bears on the origin of cracks in a clay matrix, arose from observations made while investigating the pore-size distribution (<100 nm) of clay using low-temperature (77 K) N2 sorption isotherms. The two surface areas derived, by independent means, from the adsorption and desorption branches of such isotherms are in surprisingly good agreement for a range of clays. The apparent absence of network effects, implied by this surface-area accord, can only occur if virtually all voids have access to the outside of the sample via at least one path that contains no narrower voids or constrictions. This points to the existence of a very extensive system of cracks that may form the boundaries of domains or regions of common particle orientation in clay. The formation of this system of cracks has been named intrinsic failure and is believed to result from the shrinking and swelling of the individual, randomly oriented clay domains. The possible significance of intrinsic failure is that it may be the precursor of clay cracking in general and that it may impose an upper limit on the strength of the clay matrix.
Copyright © .