Geotechnical Engineering

PDC offers consulting services that include subsurface investigations, foundation studies, pile capacity evaluation, slope stability analysis, settlement analysis with full soil laboratory testing capabilities.  Site development investigations for roadways, retaining walls, subdivision development, commercial developments have been performed throughout Southeast Alaska since 1965 by our firm.  CME-55 rotary truck-mounted drill, skid-mounted CME-45 drill rig and portable A-frame drill equipment are owned by PDC.  Standard exploration testing techniques including hollow and solid stem augers, drilling, standard penetrometer testing and diamond core drilling.

PDC provides a broad range of geotechnical engineering services including, but not limited to the following:

  • Site investigations
  • Soil bearing capacity evaluation
  • Foundation alternatives analysis
  • Pile driveability and capacity analysis
  • Embankment and excavation slope stability evaluations
  • Site grading specifications
  • Excavation, shoring, and dewatering recommendations
  • Liquefaction studies
  • Soil improvement recommendations
  • Slope stability/landslide evaluations
  • Settlement monitoring
  • Percolation testing


  • Borrow and quarry resource evaluations


Area and site geology is an important part of any geotechnical investigation.  Through geologic studies at a project site, subsurface soil and rock materials can be identified that may impact the site.  PDC geologists routinely interpret aerial photographs and geologic maps to provide input to geotechnical feasibility studies and geotechnical investigations. 

Geologic investigations include evaluating the engineering characteristics of the soil or rock to be excavated; estimate rock rippability depth; rock mass characteristics (weathering, strength, joint density, joint attitudes, etc.) as they relate to a proposed blasting program; the presence and effect of perched groundwater; existing landslides; and the construction of rock embankments.