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' - ~ ~. <br />' elevation of a massive sandstone unit which can be observed in <br />the upper portion of the entry and belt portal cuts to the west. <br />' It is speculated that this sandstone may exist relatively near <br />the surface at the location of the flow slide. <br />1 <br />' It was determined by the morning of Saturday, April 12, 1986, <br />that it would be safe to begin cautiously removing slide debris <br />t from the mine bench. It was also decided to open a slot adjacent <br />to the east end of the existing fan house, remove the buried fan <br />' and motor from that location, and install a temporary stiffening <br />buttress some 10 to 15 feet behind the rear wall of the fan <br />house. This buttress would consist of four mine cars placed in <br />' the slot normal to the slope, backf.illed with soil and tipped at <br />least 10 degrees toward the slope. The intent of this buttress <br />' was to provide enough stiffness and overturning resistance <br />immediately adjacent to the east side of the fan house to promote <br />arching between the buttress and the existing tunnel lining at <br />' the west end of the fan house. This would help to temporari ly <br />reduce any additional buildup of stress at the rear wall of the <br />existing fan house until such time as more permanent measures <br />' could be designed and constructed. <br />' Bear Mine personnel were advised not to attempt any more major <br />modifications to the existing slope at the time due to the high <br />' risk or' producing greater instability with any significant <br />excavations at the toe. Materials needed to be given sufficient <br />1 time to dewater and dry out prior to undertaking any major <br />^ earthwork. <br />5 <br />