Laserfiche WebLink
~ 12-19- 1993 4 : SSA~.1 FR0~1 LAt,18ERT 45SOC I4TES 19702493262 III I II I II III IIII III <br />9s9 <br />~i~f ~x~ ~SIIri~f~S ~ k <br />CONSULTING GEOTECNNICAL ENGINEERS AND MATERIAL TESTING <br />J. E. Stover and Associates <br />2768 Compass Drive Suite 101 <br />Grand Junction, Colorado 81506 <br />Attention: Mr. Jim Stover, <br />Subject: Density Tests for <br />Lower Twenty (20) <br />Existing Coal Gob <br />Bowie Number 2 Mi <br />Paonia, Colorado. <br />Mr. Stover: <br />P.E. <br />the <br />feet of the <br />Pile at <br />ze near <br />December 17, 1998 <br />PN: M98016MT <br />This letter is in response to our December 17, 1998 telephone <br />conversation. It is our understanding that the existing .mine <br />refuse (gob) pile was constructed without density tests is the <br />bottom twenty (20) feet of the placed fill material. Currently the <br />pile is about forty (40) feet high. <br />As discussed you would like a suggested procedure from us to <br />perform density determinations of the bottom twenty (20) feet of <br />the pile. we propose to advance several test borings on the gob <br />pile from the existing top surface to a depth of about twenty (20) <br />feet. with our track or truck mounted continuous flight auger drill <br />rig using hollow stem augers. When the Lest boring is advanced to <br />the desired depth we propose to advance continuous thin wall <br />(Shelby) tube samples through the zone of the material in question <br />to obtain samples. We suggest that we Would use two and one-half <br />(2-~/2) to three (3) inch diameter Shelby tubes with a length of <br />about twenty-four (24) to shirty-six (35) inches. <br />The moist density of the tube sample would be determined on site <br />and the sample extracted from the tube to obtain a representative <br />sample for a laboratory moisture content test. The remainder of <br />each sample would be maintained to perform moisture content-dry <br />density relationship (Proctor) tests as needed. <br />we feel that t!:is technique would provide density test data for <br />the area near the bottom of the existing pile. Th;s tech_*tique has <br />same limitations. The shelby tube is a thin walled sample tube and <br />easily is damaged by rocks during the sampling operation. We will <br />observe the shelby tube for damage as it is removed from the test <br />borings with after sampling. If damage is observed we will note i*_ <br />P. 2 <br />9. 0.80713M6 P. O. ~C7I OW! 37a 8000 OH. <br />GggNO JUNCTION, CO 11303 yONTR08E. C0 Yt dpi ~ OURANGO. CO lt]t7t <br />(970) 3~3.{30t{ lnol i~1.3151 1»07 xs~str9s <br />