Geology
Geo-Logic Associates’ geologists assess geologic and subsurface conditions to support reliable, site‑specific solutions for diverse engineering projects in challenging terrain. Geologic characterization is the “foundation” for all engineering projects.
Insight that drives smarter science and engineering
GLA’s geologists deliver site-specific insights for effective engineering solutions for fault investigations, geologic mapping, landslide assessments, seismic surveys, soil characterization, and subsurface investigations. Our geologist and engineering geologists are seasoned experts with decades of diverse in-field experience and innovated application to projects specifics.
Service Leader
Fault Investigations
GLA brings decades of expertise from hundreds of California fault investigations, delivering accurate identification of seismic hazards for safe, compliant project development. Our geologists combine advanced field methods with detailed subsurface analysis to assess rupture risk and guide sound engineering decisions. Our approach includes:
- Comprehensive literature and records review
- Detailed geologic mapping
- Fault trenching to confirm fault locations
- Examination of soil horizons and lithified strata to determine the age of the most recent rupture (paleoseismic assessment)
- Development of trench logs and surface mapping
- Site‑specific rupture risk assessment and regulatory-aligned engineering recommendations for building setbacks
Geologic Mapping
GLA delivers high‑quality geologic mapping to identify hazards, evaluate earth materials, and support precise site characterization. By combining proven field expertise with advanced global positioning systems (GPS) and computer-aided design (CAD) technology, our geologists produce detailed, accurate maps that portray the structures and stratigraphy critical to effective site design and remediation. Services include:
- Hazard identification and risk evaluation
- Assessment of earth material resources
- Site characterization for development and remediation
- Field-based structural and stratigraphic mapping
- High-accuracy GPS data collection
- Detailed CAD-generated geologic maps
Landslide Investigations
Our geologists are nationally recognized experts in landslide characterization and mitigation design. GLA’s geologists work intimately with our geotechnical engineers to develop viable, cost-effective options for landslide mitigation. We offer:
- Geologic reconnaissance
- Detailed landslide mapping and characterization
- Subsurface investigations
- Slope monitoring, acquisition, and processing of data
- Assessment of landslide mechanics, types, and various causation elements that contribute to landslide movement
- Evaluation of mitigation options
- Mitigation design, plans, and specifications
Shear Wave Velocity and Seismic Refraction Surveys
GLA offers our clients expertise in seismic refraction and refraction microtremor (ReMi) geophysical surveys. Seismic refraction methods can assess rippability of rock and depth to groundwater. The ReMi technique can assess geologic structure, stratigraphy, and for the purposes of seismic site response analyses, shear wave velocity site class.
Soil Characterizations
GLA provides detailed characterization of soil properties and structure for our clients. Our professionals have extensive experience in mapping and interpreting geologic conditions and collecting representative soil samples for laboratory analyses. We offer:
- Mapping and interpreting of geologic conditions
- Collecting representative soil samples for laboratory analysis
- Four accredited geotechnical laboratories with the capability to analyze samples to support engineering analysis and regulatory compliance
Subsurface Geologic Investigations
Our geologists develop focused subsurface investigations that minimize ground disturbance by siting boreholes and investigations at locations that maximize data value and quality while minimizing project costs. We produce investigations that result in effective designs for:
- Civil construction projects
- Environmental containment systems
- Environmental monitoring
- Remediation systems
Engineering Geology
We help clients understand complex site conditions and geologic hazards such as unstable slopes, landslides, and fault activity, and provide critical “ground truthing” for most geotechnical and engineering projects, integrating applied earth science into design, construction, and forensic investigations. Our engineering geologists have a higher degree of application-based geologic understanding and provide valuable strategic input to avoid unanticipated environmental and complex subsurface conditions that could lead to cost and/or schedule overruns.
- Geologic characterization and geohazards assessment
- Landslide assessment, monitoring and mitigation design
- Erosion, sedimentation, and scour analysis
- Rockfall hazard assessment and slope stabilization
- Stream and river (fluvial) geomorphology
- Linear project and fault source characterizations
- Mineral resources assessment
- Geologic and geomorphic mapping
- Aerial photograph and imagery analysis
- Slope stability analysis and design
- Fault trenching (Paleoseismic Studies)
- Surface and borehole geophysics
- Slope inclinometers, piezometers and observation wells
