2008-01-16_APPLICATION CORRESPONDENCE - C2008086 ‎(3)‎

• Permit No: C2008086
• IBM Index Class Name: Application Correspondence
• Doc Date: 1/16/2008
• Doc Name: Preliminary Draft Environmental Impact Statement/Subsidence
• Media Type: D
• Archive: No

DRAFT
Draft Environmental Impact Statement/Subsidence
TABLE OF CONTENTS
Page No.
1.0 INTRODUCTION ................................................... 4
2.0 DEFINITION OF TERMS AND SYMBOLS ............................... 4
3.0 GENERAL MINING INFORMATION .................................... 6
3.1 Panel Design ................................................. 6
3.2 Gateroad Pillar Configuration and Design ............................ 7
3.3 Previous Mining ................................................ 7
3.4 Multiple Seam Mining ........................................... 11
3.5 Compression Arches and Load Transfer ............................. 11
4.0 GEOLOGIC FACTORS INFLUENCING SUBSIDENCE ...................... 13
4.1 Structure ..................................................... 14
4.2 Lithologic Factors Affecting Subsidence ............................. 14
4.3 Lithology and Angle of Draw ...................................... 18
5.0 TOPOGRAPHIC FACTORS AFFECTING SUBSIDENCE ................... 20
5.1 Rugged Terrain ............................................... 20
5.2 Variable Overburden Thickness ................................... 22
'6.0 SUBSIDENCE ESTIMATION OVER CAMEO SEAM LONGWALL PANELS,
RED CLIFF MINE, PROJECT AREA ............................... 23
6.1 Subsidence Zones ............................................. 25
6.1.1 Caved Zone ............................................ 25
6.1.2 Fractured Zone .......................................... 25
6.1.3 Continuous Deformation Zone .............................. 28
6.1.4 Near-Surface Zone ....................................... 28
7.0 PREDICTED SUBSIDENCE OVER THE RED CLIFF MINE PROJECT AREA ... 30
7.1 Maximum Vertical Subsidence(Smax)•••••.••••••••••••••••••••••••• 30
7.2 Maximum Horizontal Strain ....................................... 35
7.3 Maximum Tilt(G) .............................................. 35
7.4 Angle of Draw ................................................. 37
7.5 Break Angle .................................................. 40
7.6 Rate and Duration of Subsidence .................................. 40
8.0 IMPACTS OF SUBSIDENCE ON STRUCTURALLY SENSITIVE AREAS ........ 41
8.1 Longwall Mining in Geologic Hazard Areas of Landslides, Rockfalls,
and Unstable Slopes ............................................ 41
8.2 Mining Beneath Stream Courses ................................... 42
9.0 SURFACE SUBSIDENCE MONITORING ................................ 44
10.0 REFERENCES ..................................................... 44
11.0 FIGURES ........................................................... 47
APPENDIX A. RECOMMENDED STRUCTURE LIMITS FOR SUBSIDENCE INDUCED
STRAIN AND TILT ....................................... 68
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