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, iIAR-17-98 15:12 Fram:CCiV GGLD 6t1~ <br /> <br />17196695254 • T-317 P.09/19 Job-E47 <br />Design CaU and Nicholas (>E894) CC&V (1995-6) <br />Wall <br />Orientation <br /> <br />- Inter <br />bench <br />Slope <br />(degree) Catch <br />Bench <br />Width <br />(feet) :trail Slope <br />Attg(e <br />(degree) Inter <br />bench <br />Slope <br />(degree) Catch <br />Bench <br />Width <br />(feet) Overall <br />Slope <br />Angle <br />(degree) <br />East 72° 31' S2° 79° 28' 60° <br />West 72° 48' 45° 79° 28' 60° <br />North 72 ° 40' 48 ° 79 ° 40' S2 ° <br />South 79° 40' S2° <br />"Nose's" 79° 80' 40° <br />As noted above, the steeping of the iatetramp angles along the cart highwall resulted from <br />CC&V's finding that some relatively steep natural joint sets would be intersected by the <br />highwalls. Steepening the interramp slope has provided a highwall face that is almost pazallel <br />to the natural joint se[. The steeper slope lessens the potential for failure. <br />Performance of current slope designs <br />The performance of the current design has been evaluated by inspections and measurements, <br />with the following results: <br />~ 1. Catch Bench Performance. Inspection indicates that sbout 10 percent of the width <br />of the catch benches is "used" to catch rock. There is no evidence that the majority of <br />the debris caught by these benches is the result of highwall failure. Rather the catch <br />ma[erial is the result of minor sloughing of individual "rocks" loosened by blasting. In <br />only one case has there been minor slumpage and this movemen[ does not appear to be <br />continuing. <br />2. Overall Slope Movement. Monitoring of the movemen[ of the highest, steepest slope <br />(the southern poaion of the east highwall) by electronic distance measurement equipment <br />indicates that there is no evidence of sustained progressive or pervasive movement of the <br />highwalls. <br />1 Additional Fric-ion Anpje~ormation on Cresson Ore ("Shear Box Testing") <br />With respect [o additional tests to affirm the friction angle of [he Cresson ore, CC&V noes that <br />in CC&V's January 9, 1996 submission, Attachment 7 to the letter. "Sheaz Strength Testing <br />Results for Cresson Ore," which also was dated January 9, 1996, presented an additional test <br />8 <br />