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iii iuiiuiiiiuiii 999 ~` RECEIVED _`= SUBSIDENCE MONITORING REPORT January -June 1993 JAN 21 1994 Cyprus Empire Eagle Mine No. 5, E-Seam Workings L'iri~~cn ct avnarais a Ueclogy 1.0 INTRODUCTION This report summarizes the survey schedule for and results of the subsidence monitoring of longwall mining panels in the E-seam at the Cyprus Empire Corporation (CEC) Eagle Mine No. 5 for the period from January through June 1993. No mining occurred at the mine during this period due to market conditions. Monitoring point locations are shown on the map titled, "E-seam Longwall Subsidence Monitors". This map sheet also shows mine workings, surface topography and overburden thickness. 2.0 MONITORING SCHEDULE Subsidence monitoring was pertormed in February and May 1993. These surveys included all of monitoring lines "A", "B", "C", and "D", "J", "S", and "T". Weather conditions and snow prevented complete monitoring of all points during the first quarter. 3.0 MINING ADVANCE No mining occurred at the mine during this report period due to market conditions. Mining of longwall panel 2 East was completed in December 1992. Mining of the 3 East longwall panel is projected to start in August 1993. 4.0 SUBSIDENCE RESULTS The results of the monitoring surveys are presented on the attached tables and profiles for each of the monitoring lines. The accuracy specification on the monitoring survey is 0.1 ft. Therefore subsidence values of 0.1 ft or less are not considered significant. Subsidence during this period was limited. Monitoring lines "A", "B", "C", and "D" experienced no additional subsidence. This is consistent with the low overburden cover at the locations of these monitoring lines. Monitoring lines "S", and "T" appear to have experienced limited subsidence. This is most probably due to continuing, longer-term subsidence resulting from overburden consolidation. This is consistent with the 900-ft- plus overburden thicknesses that occur at the locations of these monitoring lines.