Geotechnical Engineering Services
It’s what’s underneath that matters
Every successful project starts with a solid understanding of what lies beneath the surface. Subsurface conditions—soil, groundwater, and bedrock—can make the difference between a project that runs smoothly and one that faces costly delays or long-term issues.
At R.W. Gillespie & Associates, we combine technical expertise with decades of field experience to help you make confident decisions. Whether you’re planning a building, airport, bridge, tank, landfill, or waterfront facility, our team provides the insight you need to design smarter, build stronger, and extend the service life of your investment.
By identifying potential challenges early—such as bedrock excavation, unsuitable soils, or foundation complexities—we help you control costs and avoid surprises. And by anticipating long-term performance factors, we support the durability of your facilities, reducing the need for unexpected repairs and maintenance down the road.
Some Geotechnical Engineering Services We Provide:
- Foundation & Site Investigations
- Embankment & Preload Analyses
- Slope Stability / Landslides Evaluations
- Rock Anchor Design Criteria & Testing
- Selection of Deep Foundations
- Well & Borehole Video Surveys
- Site Selection Assistance
- Gravel and Quarry Pits
- Infiltration Testing
Materials Testing Services
A successful project starts from the ground up
Quality construction depends on quality materials. R.W. Gillespie & Associates’ field and laboratory testing services give you the confidence that the materials used on your project meet the standards for safety, durability, and performance. From design and material selection through on-site testing during construction, we provide the data you need to verify compliance and reduce the risk of costly rework.
Our technologists hold certifications from leading trade organizations including NETTCP, NICET, ICC, PCI, and ACI. We are also proud to be home to the only IFC Premier Firestop-certified inspector serving Maine and New Hampshire.
In the Field
Before, during, and after construction, we provide testing and inspection services such as:
- Density testing of soils and pavement materials
- Concrete composition analysis (air content, strength, unit weight, and temperature)
- Pile load testing
- Proof and performance testing of ground anchors
- Vibration monitoring, and evaluation of control blasting measures
- Crane platform plate load tests
We are pre-qualified by the Maine Department of Transportation in the following areas:
- Highway Inspection, Construction Management, and Support Services
- Bridge Construction Inspection, Construction Management, and Support
- Aviation Facilities Inspection
- Building Inspection
- Materials Testing/Inspection
- Geotechnical Construction Inspection
In the Laboratory
R.W. Gillespie & Associates maintains an AASHTO Resource– and CCRL-certified laboratory capable of testing soils, rock, aggregate, concrete, masonry, and asphalt. Our laboratory services not only confirm compliance but also help establish construction specifications based on sound data and analysis.
Our professional staff is committed to continuous technical training and development. With extensive working knowledge of code standards, we ensure that our clients’ projects meet all requirements for compliance and performance.
Some of the 40+ laboratory tests we provide include:
- Compressive and tensile strength of concrete, mortar, and grout cylinders
- Low density controlled low strength concrete
- Marshall flow, stability, and component percentages of asphaltic concrete
- Moisture-density relationships (standard and modified Proctor)
- California Bearing Ratio
- Sieve analysis
- Atterberg Limits
- Permeability
- Soil Consolidation Tests
- Specific gravity, absorption, freeze-thaw, and sulfate soundness
- Theoretical maximum density
Code Compliance Expertise
We test and verify in accordance with nationally recognized standards, including:
- International Building Code
- Department of Defense Unified Facilities Criteria
- American Concrete Institute Building Code
- Concrete Reinforcing Steel-Institute Standard
- Portland Cement Association Masonry Handbook
- American Society for Testing and Materials (ASTM) Standards
- American Association of State Highway and Transportation Officials (AASHTO) Standards
- Maine, New Hampshire, Massachusetts, Rhode Island, and Vermont State Building Codes
Construction Special Inspections
Structural Compliance Inspections
R.W. Gillespie & Associates can provide structural compliance inspections to verify that the structural components of your project are constructed in accordance with the project plans and specifications.
- Standard reinforced cast-in-place concrete
- Pre-stressed and post-tension concrete structures
- Reinforced masonry
- Light- and heavy-gauge structural steel construction materials
- Fireproofing of structural components (SFRM & Firestop)
- Portland cement concrete inspection
- Portland cement concrete plant monitoring
- Hot mix asphalt inspection
- Hot mix asphalt plant inspection
- Relative Humidity Testing
- Floor Flatness Testing
Construction Observation
Construction observation helps verify that projects are constructed as the designer intended and documents the work, materials, construction practices, and as-built conditions that testing alone cannot provide.
- Earth fill placement and compaction
- Lightweight fills (geofoam, cellular concrete, stone)
- Rock fill placement and compaction
- Mechanically stabilized earth walls and slopes
- Boulder retaining walls
- Soil and rock anchor installations
- Pile driving
- Compaction test strips
- Settlement and vibration monitoring
- Slope inclinometers installation and monitoring
- Stone mattresses and culverts
Environmental Consulting
Sustainable Solutions
Successful development means balancing progress with protection of environmental resources and human health. R.W. Gillespie & Associates’ environmental consulting services help clients pursue low-impact, sustainable projects by identifying opportunities, anticipating challenges, and managing environmental risks.
Our team provides monitoring and analysis to ensure compliance with environmental protection requirements. For numerous projects – such as wetland replication, wastewater disposal, or construction in sensitive areas – observation and analysis are essential to ensure consistency with environmental protection requirements and may be required for groundwater discharge and other required permits.
Environmental Consulting Services Include:
- Environmental Site Assessments (ESA I, ESA II)
- Environmental Transaction Screens (ETS)
- Subsurface Wastewater Disposal
- Irrigation & Groundwater Supply
- Groundwater Monitoring
Industries Served
R.W. Gillespie and Associates provides professional services for wide variety of clients and markets. We are committed to assist you – owners, developers, designers, and contractors – in identifying and managing your project’s uncertainties. We’ll help reduce the potential for defects, delays and unanticipated costs, and help you deliver projects of higher quality, better value and less risk.
Our multi-discipline team can be advantageous during all phases of your project. R. W. Gillespie’s Geotechnical Services include site and foundation evaluations that are essential for your project’s reliability and service life performance.
Environmental Consulting Services can help improve the beneficial development and protection of natural resources. Our Materials Testing and Special Inspections group provides essential field and laboratory services for assuring and documenting project quality during design and construction phases.
Aviation
Runways, taxiways, parking areas, and airport structures all come with unique design requirements and site challenges. R.W. Gillespie & Associates works closely with your design teams to identify site conditions and recommend solutions, and with your construction teams to provide quality assurance through field observations and laboratory testing.
Commercial/Retail
From individual office buildings to entire shopping centers and industrial parks, R.W. Gillespie & Associates supports both new development and renovations. Our services in geotechnical engineering, environmental consulting, materials testing, and special inspections help owners and developers build with confidence and keep projects on track.
Education
R.W. Gillespie & Associates assists educational clients ranging from elementary schools to major universities. Whether you are planning classrooms, dormitories, athletic facilities, or administrative buildings, we can be an integral part of your site selection, design, and construction team.
Energy
Resilient and sustainable energy infrastructure is critical to our communities. R.W. Gillespie & Associates’ portfolio includes power generation, transmission, and distribution projects across fossil, hydroelectric, biomass, geothermal, and wind generation, as well as natural gas pipelines, transmission structures, substations, and compressor stations.
Government
R.W. Gillespie & Associates is proud to support local, state, and federal agencies, including the Department of Defense. Our projects have ranged from aviation and naval facilities to fire and police stations, salt sheds, drinking water supply and treatment systems, parks, recreation facilities, and military training sites.
Infrastructure
Infrastructure is important for a community’s public health and economy. It also conveys the community’s public image. Maintaining welcoming, sustainable and safe infrastructure can be a particular challenge for a community. From major highways to clean water, for major and minor roads, bridges, and sidewalk and trail construction, R.W. Gillespie & Associates can provide geotechnical engineering, environmental, and construction material testing services for both the private and public sector.
Medical
Healthy, safe, and sustainable infrastructure supports community well-being and economic growth. R.W. Gillespie & Associates’ extensive experience makes us a valuable partner to your project team throughout site selection, planning, design, and construction. We have supported a wide range of medical facilities, including hospitals, outpatient and back-office spaces, urgent care centers, treatment clinics, and parking structures.
Mining
R.W. Gillespie & Associates provides geotechnical and environmental services for gravel pits, borrow pits, and quarries. Our work includes soil and rock investigations, material quality assessments, slope stability and landslide evaluations, groundwater monitoring, vibration monitoring, permitting support, and construction observation.
Telecommunications
From self-supporting towers to guyed structures, R.W. Gillespie & Associates helps clients reduce risk, control development costs, and improve the reliability of their telecommunication facilities.
