2014-03-07_REVISION - M1988112 ‎(3)‎

• Permit No: M1988112
• IBM Index Class Name: REVISION
• Doc Date: 3/7/2014
• Doc Name: Tailing dam report TR33
• From: DRMS
• To: McClure & Eggleston, LLC
• Type & Sequence: TR33
• Email Name: WHE
• Email Name: GRM
• Media Type: D
• Archive: No

TABLE OF CONTENTS
1.0 PROJECT DESCRIPTION .................................................................... ..............................1
1.1
Project Background .................................................................... ..............................1
1.2
Tailing Facility Design and Construction .................................. ..............................2
1.3
Tailing Facility Operation .......................................................... ..............................4
1.4
Existing Instrumentation and Monitoring Program ................... ..............................4
2.0 INITIAL INSPECTION OBSERVATIONS ......................................... ..............................6
2.1
Operational Status During Inspection ........................................ ..............................6
3.0 STRUCTURAL STABILITY ................................................................ ..............................7
3.1
Summary of Existing Data and Analysis ................................... ..............................7
3. 1.1 Embankment Design ...................................................... ..............................7
3.1.2 Results of Previous Studies ............................................ ..............................8
3.1.3 Monitoring Data ............................................................ .............................10
3.2
Visual Assessment of Dam Stability ......................................... .............................10
3.2.1 Slumps, Cracking and Settlement ................................. .............................11
3.2.2 Erosion Gulley in Right Abutment Groin ..................... .............................12
3.2.3 Drain Outlets ................................................................. .............................14
3.2.4 Piezometers ................................................................... .............................16
3.3
Results of New Evaluations Performed as part of Detailed Inspection
Analysis..................................................................................... .............................16
3.3.1 Steady Seepage Analyses .............................................. .............................16
3.3.2 Static Stability ............................................................... .............................18
3.3.3 Stability under Flood Loading ...................................... .............................18
3.3.4 Stability under Earthquake Loading ............................. .............................20
4.0 HYDROLOGY/HYDRAULICS .......................................................... .............................22
4.1
Summary of Existing Data and Analysis .................................. .............................22
4. 1.1 Impoundment Elevation- Area - Volume ........................ .............................22
4.1.2 Drainage Area and Runoff Conditions ......................... .............................24
4.1.3 Existing Hydrologic/Hydraulic Design Data ................ .............................24
4.1.4 Previous Design Analyses ............................................. .............................25
San Luis Project Miller Geotechnical Consultants
Tailing Dam Data Report ii February 2014