In a drying soil, a crack initiates when the tensile
stresses exceed the soil strength. Crack propagation is considered to be governed by the stress state
in the crack front and subsequent dissipation of
fracture energy, for which Fracture Mechanics Theory
can be used. In this context determination of fracture parameters (tensile strength, fracture toughness)
is essential in determining the cracking behaviour.
Characterizing the soil for these two parameters
require two different testing equipments. The tensile strength was determined using existing equipment
(direct method) at the Soil Mechanics Laboratory of
UPC whereas new equipment was designed for the
fracture toughness determination.
