PERMFILE131582

• Permit No: C1980007
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: EXHIBIT 60A SUBSIDENCE EVALUATION REVISED MINE PANEL LAYOUTS
• Media Type: D
• Archive: No

WEST ELK MINE: SUBSIDENCE EVALUATION
OF THE REVISED MINE PANEL LAYOUTS
IN SECTION 21 AND SECTIONS 26 AND 27
INTRODUCTION
This report describes the results of Wright Water Engineers' (WWE's) evaluation of the
subsidence effects of panel layout revisions in Section 21 and Sections 26 and 27,
Township 135, Range 90W, 6'" P.M. The subsidence effects were determined using the
Comprehensive and Integrated Subsidence Prediction Model (CISPM) developed by Dr.
Syd Peng. Additionally, Mr. Rich Dunntd reviewed the model inputs and compazed the
model results to those he developed in Exhibit 60 of the Apache Rocks Permit Revision.
All of the mining panels evaluated in this report aze located in the B-seam and aze
• planned to be mined at a height of 12 feet. The Section 21 panels aze located in the
original 5-year permit azea; whereas, the Sections 26 and 27 panels aze located in the
Apache Rocks permit revision azea.
•
PANEL LAYOUT REVISIONS
The revised panel layouts for Section 21 and Sections 26 and 27 are shown in Figure 1.
In Section 21, the original three-panel configuration has been changed to two panels of
longer length. The key parameters corresponding to the original and revised layouts aze
summarised in Table 1. The panels are numbered from east to west. A compazison of
the parameters shows that the panel widths remain the same, the panel lengths increase
slightly, and the overburden thickness of the panels for the two layouts are compazable.
rig r arer Engineers, nc. 83 -037.21