Answer Happy

The great circle of a rock slope is shown in the stereonet in Fig. The rock slope is formed at an orientation of N270/60° (dip direction/dip). Five major discontinuities were identified and with their corresponding Poles also plotted on the same stereonet. The average angle of frictional resistance of the rock discontinuity is 20 Evaluate, with explanation, the stability of the slope in terms of kinematics with respect to the discontinuities represented respectively by each of the Pole. Great circle of slope . . 5 3 2 1 Fig. Stereonet (b) Rock mass Rating RMR was used to formulate the design strategy for a tunnel. Site investigation provides the following data of the joint set for rock mass classification. - Joint orientation The strike is perpendicular to the tunnel axis, and drive against dip with Dip angle between 220 - 28° - Point Load Index 11 MPa - ROD 60% - Joint spacing 0.5 m - Joint Condition Slightly rough surfaces Separation < 1 mm Slightly weathered walls Groundwater condition Wet Evaluate the rock mass by determining the Rock Mass Rating (RMR) using Appendix II. State your assumptions, if any, in your answer.