Laserfiche WebLink
~~ <br /> <br />DECEMBER SUBSIDENCE REPORT <br />EXTRACTION LIMITS <br />Map HGP-4A, Mine Map Eastside Mine shows the limits of extraction <br />at the Eastside Mine up to the month of December 1985. The last <br />survey of the points was conducted in December. <br />OBSERVED SUBSIDENCE <br />The data from previous surveys was averaged and then the December <br />data was compared with those averages. The differences are <br />shown in the enclosed table. Points 2, 7, 8, and 9 surveyed <br />elevations are .24 to .44 feet higher than the average of the <br />two previous two surveys. This can be attributable to possible <br />survey error or not placing the level rod on the ground due to <br />snow on the ground. Point 1 which is directly over the portal <br />entrances has no observable movement. <br />The limits of mining preclude any subsidence occuring at any <br />point except point 1. As pillars are left in the area of point <br />1 no subsidence has occurred at the present time. Subsidence is <br />not anticipated until pillar extraction commences in the future. <br />PROJECTED VS SECONDARY EFFECTS OF SUBSIDENCE <br />No structures will be effected by subsidence from the E Seam <br />east of Harvey Gap. Due to the extent of mining and pillars <br />being left to support the main entries neither structures nor <br />aquifers have been effected by subsidence <br />