1987-12-01_PERMIT FILE - C1981017 (286)

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Chapter V Following are the area types and methods studied. TYPE (1): HIGH SOIL CUT, ROAD The high soil cut road was chosen as representative of areas excavated in steep slopes, often up to 45 degrees, in colluvial soils, with no rock outcrops. The highest-cut portion is very steep, up to vertical, although lower cuts are usually flatter. Although overall stability is generally satisfactory, sloughing and erosion are frequent problems, and eroded material fromt he cut face tend to accumulate in the ditch or cut toe. The reclamation objective is to create a flatter, more uniform slope by flattening the cut at its crest. A buttress was placed at the toe of the cut, and a ditch running alongside the buttress toe. Sufficient space was maintained for a light-use road between the fill and the outside edge of the ditch. In carrying out the reclamation program, a dozer and backhoe are used to push material from the crest area over the cut crest. The material is spread at the toe of the cut in lifts not exceeding 12 inches, and compacted by several runs of the tractor. A ditch at the toe of the buttress is then excavated, and the surface of the flattened cut and of the buttress are contoured with a backhoe or front-end loader. TYPE (2): HIGH ROCK CUT, MINE BENCH The bench was cut out of steep slopes, generally more than 45 degrees, generally in rocks of the Mesaverde Formation (sandstones, siltstones and claystones). Rocks in the cut may be weathered, and part of the cut close to the crest may be in colluvial soils. Overall stability is generally good, although rock and soil fall from the upper cut, where excavated in colluvial soils or weathered rock 6 to 10 feet thick, may be severe. The reclamation objective is to increase the long-term stability of the cut. A low buttress, placed at the toe of the cut and contoured, serves as a catching space for rock fall. In carrying out this reclamation program, material from the fill opposite the rock cut is placed against the cut toe as a buttress. If there's no such material available, another source of borrow material will be found in the vicinity. The buttress will act as a structure to protect against rock fall. 30 .