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- 13 - <br />• The upper cut portion consists of four benches separ- <br /> ated by three protective berms. Because of the benching con- <br /> cept, the overall cut slope is flat. Individual bench slopes <br /> are steeper, between 42 to 80 degrees, depending on the <br /> quality of rock. The steepest cut slope is in the uppermost <br /> bench that is located in one single layer of sound and re- <br /> sistant sandstone. <br /> There are no signs of instability at this rock cut <br /> except for rockfall and sloughing. Sloughed material from the <br /> bench faces acccumulates at the toe of the cut at the surface <br /> of the intermediate berms. All berms are accessible and can <br /> be periodically cleaned, if necessary. <br /> We have not identified any larger potential stability <br /> problems within this cut and we feel that it has been well <br /> designed and constructed. We do not feel that any remedial <br />• measures are necessary at this cut at present. <br /> The portal cut above the portal level and below the <br /> road is a rock cut that has been excavated at a very steep <br /> slope. In most of its parts, it is vertical with local flat- <br /> tening where rocks of inferior quality have been encountered. <br /> The uppermost part of the cut is formed by a distinct sound <br /> sandstone ledge. This ledge is underlain by softer rocks, <br /> such as shales and coal. Because of the interbedded softer <br /> and harder layers of rock, problems of rockfall are evident <br /> at this cut. A protective fence has been erected at the toe <br /> of the cut to prevent any safety hazard. <br /> Because of the favorable orientation of the planes of <br /> mechanical discontinuity, such as bedding planes and joints, <br /> there is no serious stability problem at this cut. Problems <br /> of rockfall from the cut face cannot be avoided under the <br /> cEOHrwo oaisunw, iNC. <br />