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Msrch 1991 CoM Rsfuss R'ssficiry Results end Rdr(ed Sfebi/iry /mp/ics(ions ~ I <br />• The refuse pile is currently being constructed from both coarse a~ fine refuse materials. Currem placement <br />proportion is one lik of fine refuse to ore or more liks of coarse refuse with the potemial for some variance <br />with chattges in geologic and mining conditions. it is expected that the 5re reftrse material has lower strength <br />properties, therefore, for the stability analyses it was conservatvely assumed that the entire pile waz made up <br />of fire refuse. The strength properties assumed for the fire refuse are a~mm~ri>~ below: <br />Friction Attgle - 33 degrees <br />Cohesion - 0 psf <br />Unit Weight - SO pcf <br />~J <br />• <br />The above values were based on a series of direct sheaz tests conducted on the fire refuse by GeoWest (1988)'. <br />The direct shear test results indicted a friction angle of 33 to 35 degrees. The lower end of this range was <br />conservatively used in the stability analyses. <br />A friction angle of 33 degrees is consisrent with the sample descriptions and the plasticity test results presettted <br />in Table C-1 and on Figure C-I. Attached as A[rachmem C~ are published correlations of [ricdon angle with <br />material description and phssticity index (Tenaghi and Peck, 1967)'. Both of the correlations indicate than a <br />friction attgle of 33 degrees, under drained conditions, is reasonable for the fire refuse. <br />Based on the coasisterey of test results from samples obtaired from different parts of the refuse pile and from <br />the preparation plain, it is our opinion that further testing of the fire refttse material is not warranted and that <br />the strength properties used in the stability analyses are appropriate. <br />' GeoWest (1988), 'Reevaluation ojRefuse Pile Stability jot Modified Placona(t Prauices' <br />= Terraghi and Peck, 1967, 'Soil Mechanics in Engineering Practice' Second Edition, 1967, ]ohn Wiley <br />& Sons, Ire. New York, NY. <br />~,...,~e <br />~~~ <br />