Our clients value our specialized skills and experience in geology, geophysics, groundwater hydrology, seismology, and rock mechanics. One of Schnabel’s key strengths is recognizing and addressing geological issues so they can be addressed at the appropriate design level, thus avoiding unexpected issues that cause cost overruns and schedule delays.

Our geoscience professionals work closely with geotechnical and geostructural engineers and environmental scientists to provide full-service site investigation and characterization services. Our expertise is in identifying and understanding geologic hazards as well as the impacts of complex subsurface conditions on engineering design and construction issues.

Geophysical Services

  • 2D and 3D resistivity imaging
  • Electromagnetic induction (EM)
  • Ground penetrating radar (GPR)
  • Seismic refraction
  • Surface wave surveys (MASW)
  • Magnetics
  • Micro-gravity
  • Self potential profiling
  • Induced polarization imaging
  • Downhole geophysical surveys

Seismic Hazard Evaluations

  • Probabilistic seismic hazard analysis
  • Fault mapping
  • Ground response analysis
  • Liquefaction analysis

Rock Mechanics

  • Rock slope engineering
  • Rockfall hazard analysis
  • Excavation stabilization
  • Rippability studies
  • Geomechanics modeling
  • Underground excavation design

Engineering Geology

  • Karst assessment and mitigation
  • Geologic mapping
  • Landslide evaluation and remediation
  • Identification of borrow sources
  • Site characterization
  • Evaluations of natural hazards


  • Hydrogeologic site evaluations
  • Groundwater modeling
  • Aquifer testing
  • Geochemistry evaluations
  • Vibrations Vibration monitoring and analysis
  • Pre-construction condition surveys
  • Damage claim evaluation
  • Expert witness testimony

Key Contacts

Paul E. Diggs, PE

Principal / President, Geoprofessional Services

Chad C. Mayers, PE

Chief Operating Officer
Board of Directors

M. Jonathan Harris, PE

Senior Associate / National Practice Leader for Dam Safety and Risk