AUTOMATED SLOPE STABILITY MONITORING OF A LARGE UNSTABLE SLOPE

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AUTOMATED SLOPE STABILITY MONITORING OF A LARGE
UNSTABLE SLOPE
Association of Environmental Engineering
Geologists 50th Annual Meeting Los Angeles,
California September 26, 2007
William F. Kane Charles W. Novotny KANE GeoTech,
Inc. Stockton, California Jeff L. T. Owen
Abebaw Anbessaw Los Angeles Department of Water
Power Los Angeles, California
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Outline

• Overview
• Geology
• Instrumentation
• Monitoring System Design
• Installation
• Implementation
• Summary Conclusions

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Overview
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Looking Southwest
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Looking Northeast
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Original Site Conditions
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Landslide Overview
New Scarps Develop After Winter of 2005
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Scarps Formed Winter 2005
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Geology
Pelona Schist
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Time Domain Reflectometry (TDR)
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Principle of TDR
1. Coaxial sensor cable grouted into borehole
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Coaxial TDR Sensor Cable
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TDR Multiplexer
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Campbell Scientific TDR100 Reflectometer
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TDR Data - Landslide Example
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A
0
B
-20
-40
-60
-80
Depth (Feet)
-100
-120
-140
-160
-180
Legend
A - 4 Apr 98
-200
B - 23 Jun 98
-220
0
15
30
45
60
75
90
105
120
135
150
Relative Reflectance (millirhos)
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Vibrating Wire Piezometer
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Vibrating Wire Piezometer
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Campbell Scientific Datalogger
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Monitoring System Design
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System Schematic
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Slope Cross-Section
Apparent Dip 25
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Installation
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Sensor Cable
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Sensor Connections
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Instrumentation Enclosure
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Instrumentation
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Implementation
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Server Software Architecture
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TDR Sensor Data
Monitoring Station
End of Sensor
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Piezometer Data
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Summary Conclusions

• Large Application of TDR for Slope Monitoring
• Expandable
• Can be Enhanced with Multiple Alert Features
• Excellent Application for Safeguarding
  Infrastructure Threatened by Dangerous Slope
  Movements

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THE END Thanks For Your Attention!