Characterization of three-dimensional random crack network in soil using CT test

Cracks in soils are three-dimensional (3D) and provide important preferential pathways for rainfall infiltration. The geometrical properties of 3D cracks are crucial parameters for analysis of seepage in discontinuous soils or rocks. However 3D crack planes in soils are still largely unknown because the cracks in soils are prone to disturbance and sensitive to moisture content. This paper presents a method to characterize 3D crack planes in soils by employing a nondestructive Computer Tomography (CT) test. The traces of cracks are first obtained from sections along three directions in the CT test. Then three criteria are proposed to determine a crack plane based on these crack traces. Finally the random crack network in the soil is established by assembling the planes. The probability distribution and statistical parameters can be obtained based on the obtained crack planes.