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Influence of fault on site selection

Short answer

Active faults can rupture dams and cause leakage; fault zones create weak, crushed rock leading to collapse, water inflow, and sliding. Structures are avoided on fault traces, set back with a setback zone, or founded on treated ground with concrete plugs and grouting.

How does fault influence the site selection criteria?

  • Dams and reservoirs: an active fault can rupture and break the dam; fault zones give leakage paths and weak foundation, so sites on or near a fault are avoided or require major treatment.
  • Tunnels and portals: crushed fault zones cause roof collapse, squeezing and inflow of water.
  • Slopes and buildings: faults dipping out of a slope give sliding; buildings should not straddle a fault because of differential settlement and seismic risk.
  • Bridges and roads: fault displacement can damage piers and alignments.
  • Alternatives: site should be moved away from the fault trace (a setback zone of tens to hundreds of metres), or the foundation must be excavated and treated by concrete plugs and grouting.

✓ Answer checked by Claude Opus 5.5 (high effort)

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