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<br />ROOF COIJTROL <br />Owing to the generally higher strength rocks in the Upper <br />Wheeler roof, no major strength related problems are expected. <br />Slaking will be a localized problem wherever claystones and silt- <br />stones occur in the immediate roof. Roof control problems will <br />probably be most strongly related to jointing and the roof control <br />plan should consider the spacing and spatial orientations of these <br />discontinuities. Bolting and posts should control most problems. <br />Mining of the lower seam will present a variety of problems re- <br />lated to roof control and seam interaction. Additional rock <br />mechanics studies should be conducted. <br />FLOOR FEARING CAPACITY <br />Local rutting <br />form the immediate <br />In terms of floor <br />• strata beneath the <br />major problems are <br />may occur <br />floor, but <br />weave, the <br />immediate <br />expected. <br />whenever carbonaceous claystones <br />it should not be a major problem. <br />general bearing capacity of the <br />floor, rock is quite high and no <br />CAVABILITY <br />The actual roof cavability in gob areas may not be as good <br />as desired, owing to the high strength roof rocks. Data on the <br />jointing and cleat sets would be desirable to more fully assess <br />the strata mechanics. The occurrence of several closely spaced <br />joint sets would greatly aid cavability and prevent high stress- <br />ing of abutment and other pillars. <br />SEEGMILLER hTERVATIOIAL <br /> <br />