2008-12-10_REVISION - C1981010

• Permit No: C1981010
• IBM Index Class Name: Revision
• Doc Date: 12/10/2008
• Doc Name: Trapper G-Pit Landslide Mining Assesment
• From: Agapito Associates Inc
• Type & Sequence: PR6
• Media Type: D
• Archive: No

.1[inutiI'V 15. 7008
LIST oM TABLES
Ptige !1
Liu
'fable 1. Summary of Laboratory Testing Results ............................................................ .......8
Table 2. Mechanical Properties Used in the ZD-02 Spoil Calibration FLAC31) Model .... .....24
Table 3. Results from Spoil Strength Calibration Cases ................................................... .....26
Table 4. Mechanical Properties Used in the G-Pit Spoil Stability FLAG Model ............... .....28
't'able 5. Summary of Results for Cases Analyzed ............................................................ .....30
Table 6. Estimate Recoverable Reserves from Landslide Area ......................................... .....53
LISTOF FI(;uRES
Page
Figure 1. Aerial Photograph with Location oflnitial Characterization Boreholes and
Outlines of Landslide Extent and Massive Slide Block ............................................. ..4
Figure 2. Post-Landslide "Topographic with Location of Initial Characterization Boreholes,
Phase II Boreholes, and Water Monitoring I loles .................................................... ..5
Figure 3. Projection of Previous Characterization Boreholes 05-GI-CCR through
05-G5-CCR to Approximate Location in Landslide ................................................. ..7
Figure 4. Stress-Strain Curve for Q-Floor Mudstone Sample from 07-GI7-CCR from 227 R
Below Collar ........................................................................................................... ..9
Figure 5. Lithology for Borehole 07-GI I -CC'R ..................................................................... .12
Figure 6. Lithology for Borehole 07-G12-CCR ...................................................................... 13
Figure 7. Lithology for Borehole 07-G1 3-CCR ..................................................................... .14
figure 8. Lithology for Borehole 07-G14-C'CR ..................................................................... .15
Figure 9. Lithology for Borehole 07-Gl5-C'CR ..................................................................... .16
Figure 10. Lithology for Borehole 07-GI6-CCR ..................................................................... .17
Figure 11. Lithology for Borehole 07-GI7-CCR ..................................................................... .18
Figure 12. Lithology for Borehole 07-GX5-C'C'R .................................................
Figure 13. Lithology for Borehole 07-GX6-CCR .................................................................... .20
Figure 14. Surveyed Section ofZ-Dip Cut #2 Pit Spoil Failure Showing Pre-Slide and
Post-Slide Profile
Figure 15. Conceptual 3D Model ofZ-Dip Cut #2 Pit Spoil Pile ............................................. ..
Figure 16. Unstable Velocity Contours and Large Displacement Vectors for Cases where
Spoil Strength is at the Limit of Equilibrium from Model ofZ-Dip Cut #2 Pit
Spoil Pile
Figure 17. FLAG Model Cross Section Simulation ofG-Pit Spoil Pile with a Slope of 37.6°
Illustrating Material Groups and Groundwater Table .............................................. .29
figure 18. Contours of Velocity at I`quiIibriuin For 1.311:1 V Slope Angle and 68-it-high
Pile Under Saturated Residual Strength Condition fir Q-Floor Mudstone Bedding
Dipping at 13° ........................................................................................................ .31
Figure 19. Contours of Velocity at Equilibrium for 1.311:1 V Slope Angle and 3041-high
Pile Under Saturated Residual Strength Condition for Q-Floor Mudstone Bedding
Dipping at 25° ...............
Figure 20. Flevation Contours ofQ-Seam Floor in Feet Above MSL in the K-Pit Area of
the M ine ................................................................................................................ . 34
Figure 21. Slope Contours ofthe Q-Seam Floor in Degrees in the K-Pit Area ......................... .35
Figure 22. l lighwall Stability Failure at G-Test Pit in 2001 ..................................................... .36
Figure 23. I lighwall Slope Stability Failure at G-Strike Pit After August 2004 Failure ........... .37