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SUBSIDENCE MONITORING REPORT July -December 1992 Cyprus Twentymile Coal Company, Foidel Creek Mine 1.0 INTRODUCTION This report summarizes the survey schedule for and results of the subsidence monitoring of longwall mining panels in the Wadge Coal Seam at the Cyprus Twentymile Coal Company's (TCC) Foidel Creek Mine for the period from July 1992 through December 1992. Monitoring point locations are shown on the map titled, "Subsidence Monitoring Status Map". This map sheet also shows the extent of existing mine workings, projected mine workings, surtace topography, structures, and overburden thickness. TCC completed installation of the Fish Creek AVF monitoring network in December 1992. The locations of these monitoring points are also shown on the map sheet. Baseline surveys had been completed by the end of December and weekly monitoring had been initiated. Analysis of the baseline data is ongoing at this time. The results of surveys for the Fish Creek AVF monitoring net will be reported as part of the first semi-annual report for 1993. The remainder of this report describes the results of monitoring of the original "A" and "B" profile lines. 2.0 MONITORING SCHEDULE Subsidence monitoring was performed in September 1992. This survey included all of monitoring lines "A", and "B". Weather conditions and snow prevented monitoring in December. 3.0 MINING ADVANCE Monthly longwall mining advance for this reporting period, as well as total mining to date, are shown on the map. Average extraction height during the reporting period was between 8.5 ft and 9.0 ft. The profile lines are well outside of the area of influence of current longwall mining. Mining of longwall panel 3 Left was completed in November 1992. Mining of the 2 Left longwall panel is started in mid-December 1992. 4.0 SUBSIDENCE RESULTS Cyprus Tnenlynile Semi-enneul SuMNam Repot February 13, tpB3 peps 1