Originally founded as a soils and foundations specialty consultant, GZA has grown to provide environmental, ecological, water and construction management services. Yet our roots remain in the subsurface, and we have continued to maintain our excellence for providing geotechnical solutions.
Our geotechnical design services start with a thorough review of the site history, followed by a carefully tailored site and subsurface exploration program and development of solutions for design and construction of the type of foundations and/or associated geotechnical services for each project. Our solutions are based on a combination of engineering experience and expertise, innovation, sensitivity to client needs, and responsiveness tailored to the specific permitting, structural or construction constraints associated with each site.
GZA recognizes that project specific site conditions and locations provide unique challenges that are overcome with the use of specialized equipment to access locations.
GZA designs exploration programs using the testing and exploration methods that are tailored to the needs of the project to evaluate subsurface conditions as well as to satisfy the regulatory requirements for each type of project.
- Test Borings
- Test Pits
- Cone Penetration Testing
- Geophysical and Seismic Surveys
- Geologic Mapping & Rock Slope Characterization
- Borehole Geophysics
- In-Situ Strength
- Soil Permeability and Rock Packer Testing
- Subsurface Data Management
- Geotechnical Data Reports
GZA's geotechnical engineers provide the design expertise to evaluate the engineering parameters and project requirements to provide the most appropriate foundation solution for the project.
GZA works with the project team to develop foundation designs that best fit client needs, then supports the team through bid and construction phases to provide the highest level of service to our clients. Our diverse experience for designing, reviewing and overseeing a variety of project and client types for local, national and international projects during construction of deep and shallow foundations has allowed us to develop cost-effective and/or innovative solutions to address the specific ground conditions encountered at each site.
- Drilled Shafts
- Driven Piles
- Drilled & Auger Cast Piles
- Ground Improvement and Ground Modification Design
- Mat Foundations
- Retaining Walls & Slopes
- Embankment & Foundation Settlement
- Blasting & Vibration Control
- Permanent Groundwater Control Systems
- Underpinning Systems
- Geotechnical Interpretive Reports
- Risk Registers
GZA has extensive experience in all aspects of the design and construction of temporary and permanent cofferdam cells, deep excavation shoring, earth slope/embankment stabilization, and dewatering systems in a variety of simple to complex geotechnical environments.
Whether working for the design team or providing contractor support services, the constructability and economics of alternative earth retention and dewatering systems are evaluated for each project. For constrained sites, the temporary earth support walls may be integrated into the permanent structure. Where protection of adjacent structures is a critical design consideration, GZA uses finite element and finite difference computer-modelling analyses to evaluate water seepage, ground pressure, and lateral deformations of the ground and wall systems and associated impacts on the adjacent structures.
- Slurry Walls, Secant Pile Walls
- Soil Nail Walls, Soil Mix Walls
- Soldier Piles & Lagging, Sheeting & Cofferdams
- Gravity Walls, Cantilever Walls, Anchored Walls, Soil Nail Walls & Mechanically Stabilized Earth Walls
- Tie Backs & Internal Bracing Systems
- Soil and Rock Stabilization
- Dewatering Systems
- Finite Element and Finite Difference Modeling
- Controlled Demolition
- Shielding Design
- Peer Review Services
- Construction Specifications
Geotechnical instrumentation and deep foundation testing is routinely undertaken for the evaluation of construction effects, especially in urban areas; for verification of design assumptions; and as part of project safety programs. From program management, planning and design, through installation, monitoring and evaluation, GZA provides instrumentation and testing systems to owners, engineers and contractors on projects above and below ground.
Just as ground behavior varies from site to site, so do the goals of our clients. GZA has completed thousands of instrumentation programs and have established ourselves as one of the more reputable and reliable geotechnical field measurement and foundation testing organizations in the country. Our extensive field capabilities are supplemented by our predictive modeling, data management, theoretical analysis, design and report preparation strengths.
- Automated Data Acquisition Systems and Real-Time Web Based Data Presentation of Monitoring Data
- Measurement of Vertical and Lateral Movement of Ground, Lateral Earth Support Systems and Adjacent Facilities
- Measurement of Stress and Deformation of Tunnel Lining Systems
- Wave Equation Analysis of Piles
- Pile Driving Analysis
- Axial and Lateral Static Load Test Monitoring
- Non-Destructive Pile Integrity Testing
- Osterberg Cell and Static Load Testing for Drilled Shafts
- Cross Hole Sonic Logging & Thermal Integrity Profiling of Drilled Shafts
- Soil/Rock Anchor and Tieback Design & Testing
- Rating and Load Testing Existing Foundations
- Groundwater Pressure & Elevation Monitoring
- Vibration & Noise Monitoring
- QAQC for Earthwork & Foundation Installations, Rock Slope Stabilization and Ground Improvement
- Pre-Construction Condition Surveys
- Expert Witness
GZA understands the risk that unstable soil and rock slopes can present to constructed facilities.
At-risk slopes frequently abut critical railroad lines, highways, bridges, buildings and industrial facilities. We help owners and designers evaluate the risk of potential rock fall, and design cost-effective mitigation alternatives to stabilize the rock slope or to reliably catch the fallen rock without impacting the critical facilities. Our ropes-access personnel allow us to interact directly with stabilization contractors in the field to optimize stabilization and reinforcement construction activities.
- Field Mapping & LiDAR Survey Rock Mapping
- Rock Access Capability
- CRSP Rockfall Catchment Analysis
- Kinematic Analysis of Potential Failures
- Slope Stabilization Design and Field Oversight
- Movement Monitoring
- Geotechnical Asset Management
GZA’s experienced geotechnical engineers have planned and completed subsurface investigations and laboratory and in-situ testing to gather the needed data for a wide variety of unstable slope settings from high mountain ridges to deep river valleys and steep ocean-front and even underwater sites.
GZA’s engineers use a full range of analytical techniques to assess the risk of slope failure. Once it is established that a slope is unstable, GZA develops alternatives for stabilization to identify the balance of risk and cost that safely meets the client’s goals.
- Infinite Slope & Approximate Chart-Based Solutions
- Computer-Based Analysis of Circular Arc, Block & Complex Failure Geometries
- Finite Element Analysis for Complex Geometry, Structural Interaction, and Seepage
- Regrading to Reduce Loading or Enhance Counterweight Fffects
- Use of High-Strength Geotextiles, Lightweight Fill, Stone Columns or Piles to Reinforce Slopes
- Retaining Structures
- Ground Anchors
GZA's engineers and geologists perform seismic and earthquake engineering analyses for private and public clients for buildings, power plants (including over 10 nuclear power plants), bridges, highways, dams and tunnels.
GZA routinely evaluates seismic site classification and assesses liquefaction susceptibility. Where potentially unfavorable subsurface conditions and simple site classification would result in an over-conservative foundation design, or where it is required due to building or bridge design codes, GZA performs site response analyses to evaluate use of site-specific seismic design parameters. These analyses are often used to reevaluate geotechnical seismic design considerations such as Seismic Design Category and liquefaction susceptibility.
- Seismic Site Characterization & Risk Mitigation
- Development of Dynamic Subsurface Profile and Material Properties
- Seismic Hazard Analysis
- Site Specific Ground Motion Analyses
- Soil Liquefaction Analyses & Mitigation
- Seismic Slope Stability
With more than 40 years of tunneling experience, GZA provides engineering for design and construction of shafts, tunnels and underground chambers in soil and rock.
Tunnel construction involves many risks related to soil, rock, and groundwater conditions. Through evaluation of ground conditions and a thorough knowledge of construction methods, GZA helps clients manage these risks. The firm's experience includes sewer, water, highway, rapid transit, power tunnels and caverns. GZA has provided services to both owners and contractors, which is a testament to our practical, cost-effective solutions for underground challenges and the confidence that our clients have in our abilities.
- Alignment Selection
- Geotechnical Data and Interpretive Reports
- Geotechnical Baseline Reports
- Tunneling Boring Machine Performance Studies
- Drill-and-Blast Evaluation
- 3D Modeling of Major Rock Discontinuities
- Ground Support Design
- Groundwater Control System Design
- Tunnel Jacking
- Trenchless Construction
- Subsidence Control
- Raise-bore Evaluations
- Tunnel Muck Management
- Geotechnical & Structural Instrumentation Monitoring
- Vibration Monitoring
- Tunnel Inspection & Rehabilitation
- Risk Registers
- GBR Workshops
We have over 30 years’ experience in the construction oversight of landfill and other heavy civil construction projects to give proper perspective in developing a complete, well-defined design package.
Our plan designs coordinate properly with technical specifications, QA/QC Plan, and bid item descriptions to properly define the work, and gain like-comparison contractor bids.
- Permitting Support
- Community Involvement Support
- Liner and Cap Design
- Stormwater Management
- Landfill Gas Management
- Building Sub-Slab Ventilation Systems
Ground Source Heat Pump (GSHP) systems, also known as geothermal systems, are “green,” sustainable, energy-efficient options for building heating, cooling and hot water production.
GZA provides a combination of geotechnical and environmental expertise in support of the study, budgeting, design, permitting and construction of GSHP systems.
- Site-Specific Feasibility Studies, including Economic Analysis
- Conceptual System Design
- Site Investigation and Testing
- Pumping and/or Thermal Tests to Characterize Formation for Design
- Water Quality Testing and Permitting
- Estimation of System Installation Costs
- Bid Support Services
- Construction Phase Documentation and Owners' Representative Services