Numerical Analysis of the Mechanical Behaviors of Various Jointed Rocks under Uniaxial Tension Loading
In a complex stress field of underground mining or geotechnical practice, tension damage/failure in rock masses is easily triggered and dominant. Unlike metals, rocks are generally bi-modularity materials with different mechanical properties (Young’s modulus, etc.) in compression and tension. It is well established that the Young’s modulus of a rock mass is directly related to the presence of the fracture or joint, and the Young’s modulus estimation for jointed rocks and rock masses is essential for stability analysis. In this paper, the tensile properties in joint rocks were investigated by using numerical simulations based on the discrete element method. Four influencing parameters relating to the tensile properties (joint dip angle, joint spacing, joint intersection angle, and joint density) were studied. The numerical results show that there is an approximately linear relationship between the joint dip angle (α) and the joint intersection angle (β) with the tensile strength (σt), however, the changes in α and β have less influence on the Young’s modulus in tension (Et). With respect to joint spacing, the simulations show that the effects of joint spacing on σt and Et are negligible. In relation to the joint density, the numerical results reveal that the joint intensity of rock mass has great effect on Et but insignificant effect on σt.
Keywords: jointed rock, uniaxial tension loading, numerical analysis, discrete element method