Abandoned Mine Lands

SubTerra, Inc. offers a broad range of services related to the evaluation and remediation of hazards associated with abandoned coal and hard rock mine projects.

Mine and Public Records Research

  • Initial screening of Mine Maps on 35 mm film (Washington)
  • Superposing mine layout and features on surface plans using AutoCAD
  • Historical air photo interpretation
  • Personnel interviews

Site Investigation: Geological, geotechnical, hydrogeological data collection and interpretation. Probe drilling to determine limits of mine workings.

Stability Analyses using probabilistic techniques to allow for uncertainty in rock properties and mining dimensions.

  • Pillar, roof and floor stability in sedimentary formations using traditional (e.g., Holland-Gaddy), ALPS or Rock Mass strength based methods.
  • Crown pillar stability using rock mass classification (e.g., “Q”) systems and FE/BE modeling

Subsidence Prediction for Abandoned Mine sites.

  • Evaluation of sinkhole potential based on empirical data and analysis
  • Prediction/estimation of remaining void height using probabilistic methods or direct site investigation
  • Evaluation of the potential for trough subsidence and prediction of the magnitude of subsidence and associated tilts and strains.

Surface Subsidence Related Damage Evaluation

Experience in the evaluation of impacts on:

  • Surface structures – residential, commercial office, large industrial (factory), airport, school, large fixed plant, retail stores,
  • Infrastructure – bridges, landfill(s), railway lines.
  • Utilities – roads, waterways, high voltage (345 kv) powerlines, telephone cable.
  • Natural features (rivers, wetlands, AVFs, cliffs, aquifers)

Design Modifications for Facilities in Undermined Areas including recommendations for subgrade preparation, foundation, and structural modifications to existing structures.

Regulatory Assistance: Preparation of permitting criteria, permit process, and development requirements for alternative surface land uses over undermined areas: Permit preparation and permit agency interaction, public meeting presentations.

Mine Abandonment or Remediation

  • Mine Backfilling and stabilization
  • Closure Designs for Abandoned Shafts, Declines and Adits.
  • Evaluation of venting needs