Tensile Fracture Characteristics of Compacted Soils under Uniaxial Tension

The tensile fracture characteristics of compacted soils are very important for the stability of earth structures. In this work, a horizontal displacement-controlled, uniaxial, direct-tension test apparatus was developed to capture the complete tensile stress-deformation response of cohesive soils. A series of uniaxial tensile tests were performed on two compacted soils, and the cracking process was observed. The tensile stress-deformation curves showed a clear postpeak softening behavior along with the development of tensile cracks. The influences of water content and dry density on the tensile strength and softening behavior of compacted soils were analyzed. On the basis of the fracture process zone concept, a method was proposed to extract the tensile stress-strain curve for the fracture process zone from the test data and a constitutive model was established to describe the complete stress-strain relationship of compacted soils under uniaxial tension. The model fits the experimental results well. (C) 2014 American Society of Civil Engineers.