Quasi-bound states, resonance tunnelling, and tunnelling ...
Tunnelling Under the Thames
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Alan Spray Ted Allen Docklands Light Railway (DLR) Woolwich Extension
description
Alan Spray Ted Allen. Tunnelling Under the Thames. Docklands Light Railway (DLR) Woolwich Extension. Geological Context. Initially Alluvium, gravels and Bullhead beds Water-bearing Upper Chalk Non-Clastic Carbonate Cretaceous period Medium – wide joints - PowerPoint PPT Presentation
Transcript of Tunnelling Under the Thames
Alan SprayTed Allen
Docklands Light Railway (DLR) Woolwich Extension
• Initially Alluvium, gravels and Bullhead beds
• Water-bearing Upper Chalk• Non-Clastic Carbonate • Cretaceous period• Medium – wide joints• Large flints – non carbonate• Relative strengths
Flint damageWater-bearing chalk
Maintenance – dry refuges
Drilled until cutter broke
Intensive pumping - luck
Repairs to cutter Dig heading Replacements/reinforcements Welding
Stronger cutters
Better investigation More remedial works
Build a bridge