Subsidence and Collapse

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Subsidence and Collapse
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Learning Objectives Supplement

• Understand the types of subsidence and the causes
  of each type
• Key controls of subsidence processes, and
  mitigation
• Human effects that promote or mitigate subsidence

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Terminology

• Subsidence/collapse
• Surface depressions resulting from failure of
  rock/soil from deeper(underground) perturbations
  usually associated with material removal by
  natural or human influences.

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Types of Subsidence

• Subsidence at or near the surface (Volume
  losses)
• Withdrawal of fluids
• Underground Mining
• Dissolution of limestone or salt deposits

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Subsidence at or near the surface (Volume losses)

• Above compressible (fine-grained) sediments
• Associated with clayey soils
• Draining or decomposition of organic deposits

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Withdrawal of fluids

• Groundwater
• Oil
• Both

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Underground Mining

• Material withdrawal (especially coal)
• Room Pillar mining
• Longwall mining
• Mine fires

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Dissolution of Limestone Sinkholes, Karst
Topography

• Controlling Factors
• Promoting Factors
• Types
• Examples
• Human Effects

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Salt Domes
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Learning Objectives Supplement

• Understand the types of subsidence and the causes
  of each type
• Key controls of subsidence processes, and
  mitigation
• Human effects that promote or mitigate subsidence