Fracture Behavior Analysis on the Effect of Joint and Hydrostatic Pressure to Rock Slope by Displacement Discontinuity Method

Abstract

This paper proposed a fracture mechanics approach for fracture behavior analysis on jointed rock slope. A computation program, using displacement discontinuity method (DDM), was developed, and the stress intensity factors (SIFs) for mode I and II (KI and KII) were evaluated by displacement discontinuities near crack tips. The initiation of discontinuity at each tip was determined by maximum circumferential stress criterion, and the equivalent SIF was used. The accuracy of the proposed method was demonstrated by a theoretical example, and the result agrees well with the analytical solution with an error of less than 1%. This approach was applied to a highway slope with the existence of joint. The influences of joint orientation and hydrostatic pressure to SIFs were investigated. The result shows that the stress concentration in joint tips results in crack initiation, and the mechanical behavior of rock mass is controlled by structural discontinuities and hydrostatic pressure. The application demonstrates that the presented method can explain the fracture behavior of jointed rock slope by SIF.