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/ II <br />SUBSIDENCE MONITORING REPORT <br />January -June 1993 <br />Cyprus Twentymile Coal Company, Foidel Creek Mine <br />1.0 INTRODUCTION <br />This report summarizes the survey schedule for and interim results of the subsidence <br />monitoring of longwall mining panels in the Wadge Coal Seam at the Cyprus Twentymile <br />Coal Company's (TCC) Foidel Creek Mine for the period from January 1993 through <br />June 1993. <br />Monitoring point locations are shown on the map titled, "Subsidence Monitoring Status <br />Map". This map sheet also shows the extent of existing mine workings, projected mine <br />workings, surface topography, and structures. <br />2.0 MONITORING SCHEDULE <br />Baseline surveys of the Fish Creek AVF monitoring network were completed in December <br />1992. Quarterly monitoring surveys were conducted in March 1993 and June 1993. <br />3.0 MINING ADVANCE <br />Monthly longwall mining advance for this reporting period, as well as total mining to date, <br />are shown on the map. Average extraction height during the reporting period was <br />approximately 8.7 ft. The profile lines 3000 and 4000 were located along and across the <br />2 Left longwall panel, respectively. Profile line 1000, located along the centerline of the <br />1 Left longwall panel, was not affected by surtace subsidence. <br />Mining of the 2 Left longwall panel is started in mid-December 1992. <br />4.0 SUBSIDENCE RESULTS <br />The results of the monitoring survey is presented on the attached table and profiles for <br />the monitoring lines. Analysis of the survey data indicates that the accuracy of the <br />monitoring survey is about 0.1 ft. Therefore subsidence values of 0.1 ft or less are not <br />considered significant. <br />Visual inspection of the monitoring lines in March 1933 and June 1993 showed no <br />observable effects of subsidence at the ground surface. <br />CttlfVS TMerrtymle Seniannua SubsiEence RepaM1 <br />Segeniber 13. 1887 Wpa t <br />