2009-09-21_PERMIT FILE - C1981010 ‎(13)‎

• Permit No: C1981010
• IBM Index Class Name: Permit File
• Doc Date: 9/21/2009
• Doc Name: Trapper G-Pit Landslide Mining Assesment, January 2008
• Section_Exhibit Name: Appendix T
• Media Type: D
• Archive: No

January 15, 2008
Page i
TRAPPER G-PIT LANDSLIDE MINING ARFAMERr
DEC i ;? ?OD8
TABLE OF CONTENTS Divissuit .._-4osoation,
Mining and Safety Page
1.0 INTRODUCTION ..........................................................................................................1
1.1 Background .........................................................................................................1
1.2 Objectives ................................................................................................:..........2
1.3 Characterization Program ....................................................................................2
2.0 LABORATORY TESTING ............................................................................................6
3.0 ROCK MASS CHARACTERIZATION .........................................................................9
4.0 SPOIL STABILITY ANALYSIS ..................................................................................22
4.1 Calibration of Spoil Strengths ........................................................................... 22
4.2 K-Pit T & S Spoil Pile Model ............................................................................ 27
4.2.1 Assumptions and Limitations ................................................................. 27
4.2.2 Methodology ......................................................................................... 27
4.2.3 Geometry ............................................................................................... 28
4.2.4 Material Properties ................................................................................ 28
4.2.5 Boundary Conditions ............................................................................. 29
4.3 Analysis Sequence and Cases Analyzed ............................................................ 29
4.4 Analysis Results ................................................................................................ 30
4.5 Spoil Pile Recommendations ............................................................................. 32
5.0 GEOTECHNICAL ISSUES FOR MINING K-PIT AND G-PIT ................................. 36
5.1 Failure Mechanisms ..........................................................................................36
5.2 Understanding of Mine Plan ..............................................................................45
5.2.1 Z-Dip Pit Mining Plan ...........................................................................45
5.2.2 A-Pit Highwall Mining And Dragline Dip-Pit Mining Plan ....................48
5.2.3 K-Pit And G-Pit Mining Plan .................................................................50
5.3 Reserve Recovery Estimates .............................................................................52
5.4 Truck & Shovel Cut Face Stability and Monitoring ...........................................54
5.5 Dragline Cut Face Stability and Monitoring ......................................................56
5.6 Groundwater Extraction and Monitoring ...........................................................57
6.0 SUMMARY ..................................................................................................................60
APPENDIX-LABORATORY TESTING RESULTS ..........................................................A-1
Agapito Associates, Inc.