DUKE GEOLOGICAL LABORATORY

Two generations of cumulative research and professional practice. Duke Geological Laboratory has worked underground in New York City since 1972 — mapping tunnel and shaft excavations as they advance, analysing the rock in thin section, and representing owners and contractors when what was encountered differs from what the contract documents indicated.

The work is done at the face, in the window between excavation and support. That window is usually a few days wide and it does not reopen. What is recorded then becomes the evidence everything afterwards depends on — the fracture sets, the fault geometry, the rock mass conditions, and the reasons a machine performed the way it did.

• Geological Tunnel and Shaft Mapping

  Face-by-face mapping as excavation advances — lithology, foliation, fracture sets, fault geometry and water conditions, recorded to station.

• DSC Claims, DRB and Court Representation

  Differing site condition claims for owners and contractors alike: what the contract documents indicated, what was actually encountered, and the geological basis for the difference.

• Petrographic Analysis

  Thin-section analysis in-house — mineralogy, texture, alteration and rock strength indicators, for igneous, metamorphic and sedimentary material.

• Borings and Fracture Analysis

  Core logging and fracture characterisation, including composite logs that reconcile multiple borings into a single subsurface picture.

• TBM Penetration Analysis

  Correlating machine performance against the rock actually encountered — why advance rates changed, and whether the ground or the equipment explains it.

• Geotechnical Inspection Reports

  Independent inspection and documentation during construction, written to stand up later.

• NYS DOT Source Reports

  Aggregate and material source evaluation to New York State Department of Transportation requirements.

• Digital Imaging and Video

  Photographic and video documentation of exposures that will not exist once the works are lined and backfilled.

• Artisanal Rock Excavation

  Dimension and building stone — quarry evaluation, stone quality and the economics of working a deposit.

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