Laserfiche WebLink
~-- _ -- <br />~~~ I~~~~~'~~~I~~~~~ <br />999 <br />3.0 RESULTS AND CONCLUSIONS <br />3.1 Mining Geometry <br />The geometry of mining is shown on the map sheet titled, "E-seam Langwall <br />Subsidence Monitors". The monthly face positions are also illustrated on this <br />map. The average height of mining in longwall panels 1 EAST and 2 EAST was <br />10 ft. <br />The B and C m nument lines lie above old F-seam room-and- illar kin s. The J, <br />S, an K monument lines lie a ove existing F-seam longwall panels. <br />3.2 Subsidence Results <br />The results of the monitoring surveys are illustrated on three profile sheets <br />showing monument lines B, C; J, S, T; and K, respectively. <br />The initial survey of each monitoring row (i.e., prior to influence by E-seam <br />mining) revealed no significant movement since cessation of F-seam monitoring. <br />Monuments in the B and C rows were not influenced by longwall mining of the <br />1 EAST PANEL. They will be influenced by future longwall mining of the <br />2 EAST PANEL. <br />Monuments in the K row appear to be near the limit of subsidence effects from <br />longwall mining of the 1 EAST PANEL. A difference of approximately 0.5 ft in <br />surface elevation was noted between the post-F-seam mining survey and the ongoing <br />E-seam mining surveys. <br />Monuments in the J, S, and T rows have subsided as a result of longwall mining in <br />the 1 EAST PANEL and the 2 EAST PANEL. Maximum subsidence observed to date is <br />approximately 8.8 ft due to E-seam mining. Total subsidence from longwall mining <br />in both the F-seam and the E-seam is approximately 12.3 ft. <br />Draw angles were not calculated from the data for this report. Draw angles will <br />be calculated once subsidence on a given line is judged to be complete. <br />Cyprus Empire Subsl dente Report <br />Fehruary 23, 1991 page 2 <br />