Laserfiche WebLink
During the quarter a toe drain rock filter was placed over the <br />sorted rock placed in the drain from station 0-30 to 2+00. The toe <br />drain was begun on August 31, 1994 and complete on September 8, <br />1994. This rock was placed in approximately a two foot lift over <br />the drain so that during sloping of the three to one final fill <br />slope, fines will not be pushed into the drain from the fill crest <br />and clog the drain. The two inch material used for the rock filter <br />was tested and approved by CTL Thompson (see attached report). The <br />rock drain, when covered with spoils will be dumped upon from a <br />height greater than fifty feet to ensure adequate rock sorting over <br />the drain material. (see photographs 30 through 33) <br />During the quarter several areas of seepage and instability <br />were discovered. On July 2, 1994 a small slide on the west side of <br />the fill area approximately from station 2+50 to 4+00 was <br />discovered. This area appeared to be an old slide area that had <br />pretty well stabilized itself. However, during the clay removal <br />excavation, 20 feet were cut from the toe of the slide and it <br />started moving again. This problem was rectified by removing the <br />sliding material from the surface of the slide. On September 27, <br />1994 another slide immediately below the previously mentioned older <br />slide was discovered near stations 1+50 to 2+50. This second slide <br />area was above the rock drain in elevation. The slide is currently <br />being excavated and the water source is being searched for. This <br />slide material will also be removed and the water source discovered <br />and drained to the larger west pit rock underdrain system. Large <br />rock capped with 2 inch minus crushed gravel will be utilized to <br />drain the water from this slide area. During clay excavation and <br />removal an area of seepage appeared on the east side of the <br />drainage bottom and was at the bottom of the clay removal zone. <br />This area also was drained to the rock drainage channel using more <br />than a 9 square foot area of crushed rock. A size analysis is <br />attached that shows that this rock may be used for filter drain <br />material (see attached CTL Thompson report). (see photographs 34 <br />through 41) <br />Attached to this report are my certification that all <br />construction requirements have been met thus far in constructing <br />the West Pit Excess Fill, and the color photographs as required by <br />the CDMG regulations concerning offsite Excess Spoil Fills. <br />~~ ~ //~~~ <br />Stephen R. Hinkemeyer <br />Sr. Mining Engineer <br />c.c. R. G. Trumbly <br />central files <br />