LAND SUBSIDENCE AND EARTH FISSURES IN ARIZONA

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LAND SUBSIDENCE AND EARTH FISSURES IN ARIZONA
Ching Sheng, Seah (ID 4147549)? Melanie Poller
(ID 2106795)? Nhu Quynh Thi Nguyen (ID
4112793)?
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• Content
• Problems
• Geological Aspects
• Solutions

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Earth fissure damage to residence in
Nevada (photo by John Bell)?
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Fissure gully near Picacho, Arizona (Photo by
S.R. Anderson, USGS)
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Fissure gully crossing below above-grade pipe at
a mine facility in Nevada (photo by AMEC
presented in 2004 ADOT workshop)?
Central Main Lateral Canal of the CAP crossing
the Picacho earth fissure (photo by Michael
Carpenter)?
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SUMMARY OF THE PROBLEMS

• Increasing of all water use
• Warming climate
• RESULTS
• Cracking of buildings
• Damage to roads, railway, storm sewers,
  underground pipelines,canals, etc.
• Cracks without advance warning

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SUBSIDENCE

• Groundwater withdraw from aquifers in sedimentary
  basin
• Bowl-shaped depression

EARTH FISSURES AND FISSURE GULLIES

• Cracks, seams or separations
• The sediment properties and stresses results in a
  subsurface rupture or separation
• Fissure Gullies erosive forces move sediment
  downward

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CRACK FORMATION
SUBSIDENCE
A
B
D
C
COMPRESSION
E
F
(Herman Bouwer - Land Subsidence and Cracking Due
to Ground Water Depletion)

• Withdrawal of groundwater in the center
• Clay beds and other formations -thickest in the
  center - thinner toward the edges
• Overlying alluvium rotate

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CRACK FORMATION
SUBSIDENCE
CRACK
COMPRESSIBLE BEDS
COMPRESSION
(Herman Bouwer - Land Subsidence and Cracking Due
to Ground Water Depletion)

• Groundwater withdrawal - ridge - alluvial
  materials - thicker
• Linearly increasing subsidence
• Overlying slabs rotate

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MONITORING AND POST CONSTRUCTION REMEDIAL ACTION

• Solution

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SUBSIDENCE MONITORING

• Geographic Information System (GIS)
• Close Range Photogrammetric System

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• Global Positioning System (GPS)
• Management tool
• Schedule
• Identify
• Evaluate

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POST CONSTRUCTION REMEDIAL ACTION

• Keep Water Path Away from earth fissures
• Sealing of surface earth fissures
  Diversion of Drainage
• Prevent erosion of surface flows -large gullies
• Solution
• Clay Bentonite mixed with soil Soil cement
• (Good in treating Enlarged fissures)
• Filling with Gravel
• (less succesfull)

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• Using Cutoff Wall
• Sheet Piling Cutoff Walls
• Water Path Earth Fissure deep stability
• (Successful but hairline cracks developed)
• Geotextile Cutoff Barriers

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THANK YOU!!