Laserfiche WebLink
APPEND. 7 (3) <br />;' am~ert ana ~~,s~ociate~ <br />CONSULTING GEOTECHNICAL ENGINEERS AND MATERIAL TESTING <br />August 5, 1993 <br />r~ <br />Mr. Don May, P.E_ <br />735 East 7th Ave. <br />Durango, .CO 81301 <br />Subject: National King Coal Direct Shear Test results <br />Mr. May, <br />This letter presents the results of our direct shear test of <br />the formational material samrled from cur tort borings leeat~ed -~ <br />northeast of the National King Coal mine maintenance and shuttle <br />storage building. The test boring was advanced on July 21, 1993 <br />at the south end of the upper surface of the coal gob pile. We <br />advanced the boring through the gob and obtained drive type <br />sleeve samples of the formational material at the elevations you <br />requested. <br />We analyzed the direct shear test data at an elongation of <br />'t'. 0.050 inch (approximately 2.5% strain)- and obtained an angle of <br />internal friction of 45 degrees and a cohesion of about 0.5 pound <br />per square inch (approximately 72 pounds per square foot). <br />Due to the variable and laminated nature of the observed <br />formational outcrop near the test boring we anticipate that the <br />physical strength characteristics vary within the unit. We <br />anticipate that the claystone portions of the material generally <br />will have a lower angle of internal friction and higher cohesion, <br />while the sandstone portions will have higher angle of internal <br />friction and a lower cohesion. The sample we tested consisted of <br />a very fine grained well sorted lithic sandstone. <br />If you have any questions, please contact us. <br />Respectfully~ sub <br />T.AMBERT ANIY~. CIATES~ <br />~` <br />~Tr er <br />Of ice Manager <br />cc: Tom Bird <br /> <br />P.O. BOX 0045 463 TURNER, 704 A <br />P.O_ BOX 3986 MONTROSE, CO 81402 DURANGO, CO 81301 <br />GRAND JUI+;CTION, CO 81502 (303} 249-2154 (303} 259.5095 <br />(303) 245-6506 - <br />May 1994 `. <br />