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<br />MINING AND RECLAMATION PLAN <br />MT. GUNNISON N0. 1 MINE <br />different locations are as follows: <br />LOCATION <br />Main Entry Seals <br />Sylvester Gulch Ventilation Portals <br />Minnesota Creek Seals (if required) <br />South Prong Seals (if required) <br />January, 1986 <br />SEAL STRENGTH <br />9.6 Feet <br />9.6 Feet <br />6.4 Feet ., <br />3.2 Feet <br />Seal Details - Mine seals will have a tapered plug shape and be built with <br />concrete material. Typical seal plan and sectional views are shown in the <br />Exhibit 3.5.2.E6. Atypical section of the mine seal for main entries and <br />ventilation portals is given in the Exhibit 3.5.2.E7. <br /> <br /> <br /> <br />Approximate location and sections of the seals in the <br />the Exhibits 3.5.2 E8 through 3.5.2.E12. As discussed <br />the roof and floor layers consists of shale, sandstone <br />sections near the proposed seal locations are shown in <br />3.5.2. E16. These sections indicate that the roof and <br />competent and represent layers of rock properties used <br />nain entries are shown in <br />in the rock properties, <br />and siltstone. Geologic <br />the Exhibits 3.5.2.E13 to <br />floor materials are <br />in the design. <br />Seal Construction - Before construction of the concrete seal at the proposed <br />locations, the loose rock and crushed material will be removed. A small cut <br />around the opening will be made to obtain the tapered plug shape. Also the plug <br />will be keyed into the perimeter of the opening using rebar or steel cables. <br />This keying of the plug into the openings will help increase shear strength <br />around the seal. All the visible major fractures in the coal pillars between <br />the seals will be grouted with concrete as necessary to avoid water leaks <br />through the pillars. <br />Summary - The permanent mine seals were designed based on the maximum possible <br />hydraulic heads and the strength properties obtained from the Mt. Gunnison core <br />samples. A safety factor of three was used in calculating the applied forces on <br />the seal and the seal dimensions were estimated. The seal strength at the main <br />entries and ventilation portals in Sylvester Gulch area is 916 feet. If <br />required, additional intermediate seals in the mine under the Minnesota and <br />3-87 <br />