2000-08-25_REVISION - M1977378 (2)

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TR -22 Submittal Page 2 MINING PLAN The proposed bulkhead was designed by John F. Abel, Jr., the same professional engineer who designed the TR -14 bulkheads, using the same design methodology and concepts. Attached is his letter report containing the design information. The proposed bulkhead will be placed approximately 300 feet from the portal timber sets. It will be 7 feet thick with #10 rebar on 6 -inch centers at the downstream face and #6 (temperature and shrinkage) rebar on 12 -inch centers at the upstream face. The concrete cover for the rebar will be 3 -inch for the #6 and 3.5 -inch for the #10. Any pipe or inspection cutouts in the rebar cage will have #6 trim bars (5 -foot long) at 45 ° . The average concrete strength will meet or exceed 3000 psi at 28 days. Tests samples will be taken to verify that this parameter is met (approximately 1 sample per 8 cubic yards). The walls will be scaled, cleaned and measured to verify that 8 -10 percent tunnel irregularity exists. DMG will be notified when the form is ready for a pre -pour inspection. The bulkhead will be low pressure grouted using the same pattern and methodology that was used with the TR -14 bulkheads. It is anticipated that a temporary drainage pipe through the bulkhead will be required for construction of the bulkhead. It will most likely be a 6" schedule 40 steel pipe and it will be grouted full as soon as the bulkhead reaches a strength sufficient to withstand any pressures that could develop on the bulkhead. A construction certification report will be submitted upon completion. RECLAMATION PLAN The approved reclamation plan for the surface disturbance will not change with this TR. No disturbance of land not previously disturbed within the permit area is required to implement the proposed work plan. All new construction will be confined to the underground workings. After placement of the bulkhead, SGC anticipates that the surface settling ponds will no longer be needed for water treatment. If this is the case, SGC plans to implement as much of the surface reclamation plan in 2000 that the weather will allow.