GEOTECHNICAL SERVICES

Columbia West is a geotechnical engineering, materials testing, and structural special inspection firm based in Vancouver, Washington. Columbia West provides the geotechnical services described below for a variety of public and private clients, including several local regulatory agencies, ports, school districts, and private developers located throughout the Pacific Northwest.

Columbia West conducts geotechnical site investigations for a variety of public and private projects in Oregon and Washington. Field investigations are conducted using soil boring equipment, mechanized heavy construction excavators, or other specialized equipment to observe subsurface soils and collect relevant data. A geotechnical site investigation report varies depending upon proposed development, but generally includes descriptions of the site and subsurface profile and a summary of geologic, seismic, hydrologic, and topographic characteristics. Cone penetration testing, pre-bored pressuremeter testing, standard penetration testing, and other in situ tests are conducted during field exploration to determine soil properties. Design recommendations and supporting geotechnical engineering analyses are provided for foundations, earthwork, drainage, slope stability, lateral earth pressure, asphalt and concrete pavement, erosion potential, and utility installation. Detailed figures, subsurface exploration logs, and analytical laboratory test results are also included.
Foundation inspections are often requested by regulatory agencies to verify adequate support conditions for footings. Columbia West’s engineers and technicians evaluate foundation subgrade conditions using testing devices including nuclear density gauges, dynamic cone penetrometers, static and pocket penetrometers, torvane shear devices, and bearing probes. Recommendations regarding over-excavation and subsequent backfill with engineered structural fill may be provided if inadequate subgrade soils are encountered or if foundations are constructed during wet weather conditions.
Geotechnical engineers are often contracted to evaluate the ability of subsurface soils to support in-ground disposal of concentrated storm water via infiltration. Infiltration analysis typically consists of exploratory site evaluation, in situ permeability testing, and laboratory analysis of soil samples collected from relevant soil horizons. Results of in situ permeability testing and laboratory analysis and recommendations based upon the results are presented in a concise report which may be used by site plan engineers in design of infiltration systems.
Columbia West’s engineers often evaluate soil bearing capacity and anticipated settlement for proposed structures for both shallow and deep foundations. To determine specific soil properties for use in design, Columbia West’s engineers conduct specialized in situ field testing using methods such as the cone penetration test, pre-bored pressuremeter test, standard penetration test, and more. Engineers then calculate bearing capacity and settlement using in situ test results, models of the subsurface soil profile, and results of laboratory analysis of soils sampled from the site.
Columbia West’s engineers have conducted numerous site-specific slope stability evaluations for a variety of projects including mine embankment slopes, active and inactive landslides, road cuts, water reservoirs, and numerous residential structures. Slope stability analysis typically includes detailed subsurface soil modeling based upon information obtained from exploratory borings, in situ undisturbed soil sampling, and extensive laboratory analysis. Topographic, geologic, and geotechnical data are used with computer modeling to determine potential slip surfaces and estimate factors of safety for slope stability.
Columbia West personnel provide construction observation and quality control testing for projects located throughout the Pacific Northwest. Nuclear gauges, bearing probe analysis, proof roll observation, and other methods are used to verify project construction compliance with approved plans and specifications. Columbia West’s engineers and technicians have experience providing construction observation and testing for a wide range of projects including schools, ports, bridges, building pads, parking lots, roadways, reservoirs, dams, and more. The location of Columbia West’s office and laboratory facility allows timely and cost-effective service for projects located throughout the Pacific Northwest.