PERMFILE138596

• Permit No: C1980007
• IBM Index Class Name: Permit File
• Doc Date: 6/2/2006
• Section_Exhibit Name: Exhibit 72 Preventative Measure, Geotechnical Eval, Seismic Eval for Monument Dam
• Media Type: D
• Archive: No

Geoteehnical Evaluation of Mine-Induced Seismicity on Monument Dam
Dorsey 6 Whitney, LLP
Table of Contents
Section 1 -Introduction 1
1.1 Purpose and Objectives 1
1.2 Background 1
1.3 Scope of Work 2
1.4 Project Personnel 2
Section 2 -Condition of the Dam 3
2.1 Description 3
2.2 Dam Components 5
Section 3 - Geology 10
3.1 Regional Geology 10
3.2 Site Geology 10
Section 4 -Seismic Loading 12
4.1 Natural Seismicity 12
• 4.2
4.3
4.4
4.5
4.6
Mine-Induced Seismicity 12
Anticipated Seismicity Associated with E Seam Mining 14
Attenuation Relationship for Mine-Induced Seismicity 14
Attenuation Relationship for Natural Seismicity 15
SEO Seismic Stability Analysis Requirements for
Modification to Dam 16
Section 5 -Stability of the Earthfill Dam 17
5.1 General 17
5.2 Data Available for Analysis 17
5.3 Liquefaction Potential 17
5.4 Representative Cross Section
5.5 Water Pressures
5.6 Material Properties
5.7 Results of the Analysis
18
18
18
19
Section 6 -Stability of the Landslide Component of the Dam 20
6.1 General 20
6.2 Pre-Failure Static Stability Analysis 20
6.2.1 Representative Cross Section 20
6.2.2 Water Pressures 21
6.2.3 Material Properties 21
6.2.4 Stability Analysis Results 22
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