GLA provides geotechnical and geoenvironmental engineering services for a wide range of commercial, infrastructure, mining, and other projects across the United States and internationally. Our highly qualified professionals provide customized solutions to enable the most efficient use of geotechnically and geologically challenging sites through application of advanced techniques and proven practice leadership. Scopes of our services are carefully planned and are designed to provide our clients with dependable, cost-effective solutions. Our services are tailored for each client and regulatory environment to meet aggressive design, construction, and approval schedules. Our design and construction oversight projects are supported by our in-house geotechnical testing laboratories, civil design and environmental professionals, and field services personnel.

Advancing the State of the Practice

GLA’s geotechnical engineering group is led by Neven Matasovic, PhD, PE, GE. In addition to his project management and company-wide engineering leadership roles, he advances the state of geotechnical practice through research and development in collaboration with leading universities. Recent topics include development of models for evaluation of stresses and strains in composite liner systems during seismic events, development of nonlinear effective-stress site response analysis models, and contributions to seismic design of municipal solid waste and hazardous waste landfills through back-analysis of case histories and advanced testing of difficult to sample and test geomaterials. Dr. Matasovic is an active contributor to Federal Highway Administration (FHWA)-sponsored research projects and has co-authored technical guidance documents for FHWA and the Transportation Research Board of the National Academies. Presently, he is heading the National Academies-sponsored project titled Guidance on Seismic Site Response Analysis with Pore Water Pressure Generation.

Dr. Matasovic leads a team of focused geo-professionals which includes eight California-Registered Geotechnical Engineers (GEs) and ten Certified Engineering Geologists (CEGs).

For further information, contact:

  Neven Matasovic, PhD, PE, GE

Our geotechnical engineering services include:

  • Beneficial redevelopment of brownfield sites
  • Earth retaining structures and excavation support
  • Earthquake engineering
  • Geohazard mitigation
  • Geotechnical laboratory services
  • Structural foundations
  • Water retention, conveyance, and infiltration systems

Beneficial redevelopment of brownfield sites

Beneficial redevelopment of brownfields sites, including roads, golf courses, parks, and various commercial construction over former landfills and contaminated sites, is often feasible and is increasingly common. Development for brownfield sites commonly involves overcoming significant engineering and construction challenges, such as settlement-mitigating or settlement-tolerant foundations, gas mitigation, groundwater protection, and use of safe site work practices. Brownfield site work also typically requires performance assessments of existing sites and compliance monitoring of closed sites. GLA plans and performs brownfield investigations, develops mitigation measures and closure design, and facilitates permitting of such sites. GLA personnel have participated in over 200 highly successful brownfields projects and have co-authored subject guidance documents, including the U.S. Environmental Protection Agency (EPA) seismic design guidance for municipal solid waste landfills (RCRA Subtitle D (258): Seismic Design Guidance For Municipal Solid Waste Landfill Facilities) and the 11th Peck Lecture Paper: Pre-Design Geotechnical Investigation for the OII Superfund Site.

Earth retaining structures and excavation support

GLA performs pre-design, design, construction supervision, permitting, and performance monitoring of earth retaining systems. This includes both static and seismic analysis, structural detailing, and drainage design in support of construction of gravity and Mechanically Stabilized Earth (MSE) retaining walls, and excavation stabilization by soil nailing and/or by rock bolts and anchors. Our staff routinely use specialty engineering software (e.g., SRWall and MSEW) as well as general-purpose engineering software (e.g., FLAC). GLA’s geotechnical engineers have designed up to 60-ft high MSE walls at landfills and for linear infrastructure.

Earthquake engineering

GLA provides earthquake engineering services for a wide range of critical projects across the United States and internationally. Our expertise applies to a host of project types, such as dams, levees, solid and hazardous waste landfills and Superfund sites, pipelines, transportation infrastructure, vertical construction, lifelines, and more. Project services encompass geologic and geotechnical engineering investigations, development of seismic design criteria, evaluation of regional and site seismicity, site response and seismic deformation analyses, soil liquefaction analyses, evaluation of seismic performance, designs to withstand seismic loading (including dams and appurtenant structures and foundations for buildings, bridges, and other structures), site reconnaissance following earthquakes, and ground vibration assessments.

Practice specialties include:

  • Site characterization
  • Seismic hazard analyses
  • Soil liquefaction evaluation
  • Site response analyses
  • Seismic stability and deformation analyses

Geohazard response, evaluation, and mitigation

A geohazard is a geological condition that may lead to widespread damage or risk of damage. If these conditions are not assessed and mitigated, natural disasters such as earthquakes and floods could prove disastrous.

Typically, an investigation in support to geohazard mitigation would begin with assessment of geologic and hydrogeologic conditions, including structural geology, stratigraphy, landsliding potential, groundwater conditions, faulting, and seismicity. Our geologists effectively use drones and Global Positioning System (GPS) units to accurately assess bedding, faulting and folding in formations surveyed. Data generated during the investigation is reviewed and used by GLA’s geotechnical engineers and geologists to inform and further to develop site models for variety of applications, including modelling of fault rupture propagation, assessment of slope stability, and siting of critical infrastructure.

Geotechnical laboratory services

GLA operates four full-service geotechnical testing laboratories. Specialized capabilities of GLA’s in-house laboratories include geosynthetic component testing, geosynthetics-soil interface testing, and unsaturated soil testing. GLA laboratories fulfill in-house needs and support a wide range of public and private clientele from local construction companies to multinational mining companies. Testing is conducted using modern equipment and in accordance with the latest testing standards.

The success of GLA’s laboratories is a direct result of the ability to provide the highest quality, experienced testing services. Our laboratory managers include licensed professional engineers with advanced degrees in geotechnical engineering. All equipment is maintained and calibrated annually in accordance with our internal Quality Assurance Program. The American Association of State Highway and Transportation Officials (AASHTO), Cement and Concrete Reference Laboratory (CCRL), US Army Corps of Engineers (ACOE), and Geosynthetics Research Institute (GRI) have certified our laboratories.

Geotechnical laboratory services include:

  • Soil classification
  • Moisture-density relationships
  • Soil shear strength (direct and triaxial)
  • Hydraulic conductivity
  • Moisture retention
  • Geosynthetics/soil-geosynthetics interfaces
  • Amended soil
  • Concrete, masonry, mortar and grout
  • Asphaltic concrete tests
  • Custom/specialized field testing

Structural foundations and ground improvement

Our geotechnical infrastructure and foundation practitioners worked on difficult and challenging sites where the development of dependable and cost-effective foundations is critical to the success of the project. They have designed numerous deep foundation systems in non-routine soils such as Municipal Solid Waste (MSW) and have developed and implemented soil improvement measures against compressible, liquefiable, expansive, and collapsible soils. GLA is an active industry partner with the “Center for Bio-mediated & Bio-inspired Geotechnics” at Arizona State University (ASU) (

Water retention, conveyance, and infiltration systems

Utilizing our expertise in geotechnical and geoenvironmental engineering, foundation engineering, water resources management, and environmental management, GLA provides a full range of innovative services for new and existing dams, dikes, reservoirs, levees, and water conveyance and infiltration systems. Our practitioners respond to unique technical and environmental challenges facing federal, state, municipal, industrial, and private owners and operators to create site-specific solutions that are efficient, cost effective, and enduring.