Open AccessMud peeling and horizontal crack formation in drying clays
Author(s) -
Style Robert W.,
Peppin Stephen S. L.,
Cocks Alan C. F.
Publication year - 2011
Publication title -
journal of geophysical research: earth surface
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2010jf001842
Subject(s) - poromechanics , materials science , curvature , spall , thermoelastic damping , geology , geotechnical engineering , radius , composite material , fissure , mechanics , mineralogy , porosity , thermal , thermodynamics , porous medium , geometry , mathematics , physics , computer security , computer science
Mud peeling is a common phenomenon whereby horizontal cracks propagate parallel to the surface of a drying clay. Differential stresses then cause the layer of clay above the crack to curl up to form a mud peel. By treating the clay as a poroelastic solid, we analyze the peeling phenomenon and show that it is caused by the gradient in tensile stress at the surface of the clay, analogously to the spalling of thermoelastic materials. For a constant water evaporation rate at the clay surface we derive equations for the depth of peeling and the time of peeling as functions of the evaporation rate. Our model predicts a simple relationship between the radius of curvature of a mud peel and the depth of peeling. The model predictions are in agreement with the available experimental data.