Fig. 3. Scheme of horizontal shrinkage deformation (horizontal cross-sections) at the drying of an isolated cube (Bronswijk's approximation) and a cube that is part of a real connected layer and only mentally outlined in it. In Fig. 3b, c, and d the shrinkage of a soil matrix in the horizontal plane is considered to be isotropic. a. The horizontal basis at w = w_o. b. The basis of the isolated cube without cracks and with free boundaries after shrinkage at w < w_o. c. The basis of the mentally separated cube with fixed boundaries after shrinkage at w < w_o. Internal tensile stresses developing at layer shrinkage lead to cracking (black strips). d. The area of the stretched soil matrix in Fig. 3c after the mental extraction of a crack area (area of black strips). The size of the stretched-matrix area, x > x'.