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• Subsidence Profile <br />The accuracy with which the subsidence profile can be predicted is limited in mining <br />regions where there has been no previous measurement of subsidence profiles. The SEH <br />method can be used to obtain the general form of the curve, but the profile obtained will <br />be in error by an unknown amount. In the North Fork Valley extensive subsidence <br />monitoring over room-and-pillar mining has been done in the last decade. Both the Bear <br />#3 mine and the Bowie #1 Mine have monitored subsidence over workings which used <br />room-and-pillar mining methods. Tables 15-1 and 15-2 illustrate subsidence results <br />measured for the two mines which are in different coal seams and the Bear #3 Mine has <br />been mined in multiple seams. <br />Table 15-1 <br />Predicted Subsidence for Bear #3 Mine thru Julv. 1994. <br />Monument Measured Predicted Comments <br />Stations Subsidence Subsidence <br />• <br />UAi 1.14 1.7 B&C-Seam on rib <br />UT2 3.26 6.1 B&C-Seam on pillar <br />U1 1.26 1.8 B&C-Seam C on rib <br />U2 0.72 1.0 C-Seam on rib <br />U3 0.34 0.7 B-Seam on rib <br />U4 2.96 4.9 B&C-Seam on pillar <br />U5 0.14 0.4 C-Seam on rib <br />US 0.40 3.0 B&C-Seam C on pillar <br />U9 0.21 1.7 C-Seam on rib <br />U10 0.64 3.1 B&C Seam <br />U11 1.44 1.3 B&C-Seam C on pillar <br />U21 5.98 5.6 B&C Super-critical <br />U22 3.48 6.8 B&C Super-critical <br />u <br />PR-08 - 7 - 07/03 <br />A P~RdVED <br />9~z s ~03 <br />