Experimental Study on the Dilatancy Behavior of Single Joints Under Constant τ/σ Loading Conditions

ABSTRACT: The mechanical behavior of jointed rock masses is strongly affected by the mechanical behavior of rock joints. In turn, the mechanical behavior of rock joints is dependent upon the relationship between the orientation of the joints and the direction of the stress (load) in the field. Thus, it is considered that the mechanical behavior of rock joints consists of three parameters, namely, normal stiffness k_n, shear stiffness k_s, and the dilatancy property. The goals of this research work are to determine these three parameters, to develop a constitutive law for rock joints, and to apply the field works of rock engineering. In order to achieve the above goal, constant t/s loading tests are carried out. The dilatancy properties of rock joints based on the results of the constant t/s loading tests are discussed in this paper, and a constitutive model for the mechanical behavior of rock joints is estimated. Comparing the theoretical analyses with the experimental results, the constitutive model is applied to the numerical simulation.