Geotechnical Testing

Exponent’s geotechnical engineering staff has extensive experience in laboratory soil testing, field testing, sampling, and monitoring. Our expertise in laboratory testing and field work allows us to provide comprehensive geotechnical services to our clients.

Our soil testing equipment enables us to perform in-house testing of soil physical properties for most of our projects. Geotechnical testing provides supporting data and represents a key component in many of our investigations, including site characterization; seismic (earthquake) studies; evaluations of soil settlement, expansive soil behavior, soil collapse potential, ground subsidence, landslide and slope stability, and moisture intrusion; and performance assessments for dams, retaining walls, and other structures.

Exponent also has geotechnical field sampling, testing, and monitoring capabilities, which enable us to efficiently collect high-quality samples for laboratory testing and perform in-situ testing and data collection. Our geotechnical engineers and geologists have many years of experience in conducting field investigations, such as geologic mapping and data collection via site reconnaissance and downhole logging, slope movement monitoring by inclinometers, groundwater-level monitoring, and in-situ strength and permeability testing.

Exponent is certified as an Approved Testing Agency by the City of Los Angeles. We also hold a Soils Permit from the United States Department of Agriculture (USDA). This permit allows us to receive and test soils from all 50 states and from foreign countries. Through ongoing collaboration with local universities, we have quick access to highly specialized equipment, such as instruments used to evaluate liquefaction or seismic compression potential or to determine soil stiffness and damping properties necessary for ground motion (seismic) evaluation. Additional outside resources are readily available for projects requiring specialized laboratory testing or state-of-the-art site monitoring (e.g., remote sensing). Our soil laboratory testing capabilities include:

Classification and Index Properties 

  • Grain-size analysis 
  • Atterberg limits 
  • Organic content 

Compressibility and Expansion Potential 

  • One-dimensional consolidation 
  • Swell/collapse potential 
  • Expansion index 
  • R-Value

Density and Strength

  • Direct shear
  • Moisture and density 
  • Compaction

Hydraulic Properties 

  •  Permeability

Our field capabilities include:

  • Soil boring and test-pit excavation supervision (or observation), logging, and sample collection 
  • Installation and monitoring of geotechnical instrumentation (e.g., piezometers, inclinometers, crack gauges, tiltmeters) 
  • In-situ moisture and density testing 
  • Shear-vane test (strength) 
  • Packer test (permeability)  
  • Ground vibration monitoring