GAI has provided design, construction and/or inspections services for over 500 dams. In the early 1990’s GAI directed the design and testing of rock anchors with capacities to 2,000,000 pounds (then the largest in the western hemisphere) to stabilize a concrete dam in West Virginia. GAI is also the geotechnical consultant for the 400-foot high earth and rock Little Blue Run Dam, which was the highest non-federal dam in the eastern US at the time of its construction. GAI converted a 58-foot high slab-and-buttress dam into a concrete gravity dam to repair the structure from deterioration.

Dam Rehabilitation Projects

GAI conducts geotechnical explorations, establishes design pressures, and provides the structural design for new retaining structures. Wall types include braced and anchored excavations retaining structures, deep soil mixed and jet grouted walls, conventional concrete gravity walls, soldier beam and lagging walls, soil and rock anchored walls, tangent caisson walls, drilled-in micropile walls, mechanically stabilized earth walls, soil nailed walls, rock bolting and mesh or shotcrete support for rock, and other wall and slope retention systems. We also evaluate and remediate exsiting walls and slopes that are either failing or are in distress.

Earth/Rock Retaining Projects

Unfortunately, there have been many structures built where designers did not recognize the potential for expansion of soil, rock or aggregate. Many times, these structures have been cracked and damaged by uneven upward movement of the expanding subgrades. GAI investigates these types of movements, determines the cause of the movement, and designs repairs to either underpin or stabilize the structure or eliminate the problem. We also incorporate testing into our geotechnical explorations when potentially expansive materials are encountered and provide foundation design recommendations to prevent damage from expansive soil, rock, or aggregates.

Expansive Soil, Rock, and Aggregate Projects 

GAI has been providing expert foundation exploration, instrumentation, design, and testing services for 50 years. Our research, analysis, and full-scale testing of laterally loaded drilled shaft foundations and directly embedded poles led to the development and calibration of the Electric Power Research Institute’s computer code, MFAD, Moment Foundation Analysis and Design, which is an integral part of their design software used nationally by electric utility companies. We have conducted large scale 4-foot square plate load tests to develop equations for design of base mats on up to 70 feet of engineered fill below power station structures with average bearing pressures of 5000 pounds per square foot. Our research for PennDot lead to the development of their procedures for design of foundations in karst (sinkhole) limestone areas, the use of flowable backfills for support of structures, and the use of dynamic pile monitoring to determine acceptable driving criteria and capacity for piles.

Foundation Research and Design Projects 

GAI provides thorough site explorations to detect geologic and environmental hazards that may have to be addressed in site or project development. We evaluate site conditions to determine the proper site seismic design criteria. We conduct geologic research and reconnaissance to determine if sites are undermined, contain collapsible soils or rock, have karst and sinkhole features, are settlement prone, contain expansive soils and rock, or contain landslide prone deposits that may have to be addressed in site design.

Geologic Studies and Subsurface Explorations

Landslides occur naturally and are man-made. GAI uses traditional and innovative solutions to stabilizing slopes and preventing damage to nearby facilities. We investigate the geology of the site and determine the characteristics of the soil, rock, and ground water that may lead to instability. GAI conducts geotechnical explorations to sample soils for testing, for installation of slope inclinometer tubing for slope monitoring, and to measure ground water seepage conditions. We conduct stability analyses and determine ways to improve the stability of slopes including excavation of driving weights, buttressing of the slope, installation of walls, drainage of the slope, flattening of the slope, reinforcing of the slope, and other techniques.

Slope Stabilization Analysis and Design Projects

GAI provides geotechnical and concrete testing services for a variety of projects. Our in-house laboratory testing services include classification, strength, compressibility testing of soils and resilient modulus testing for pavement design. We provide strength and compressibility testing of concrete, grout, and rock.

Soil Testing & Laboratory Projects

GAI’s subsidence studies include evaluations of coal mines, clay mines, limestone mines, and karst conditions. We do research into the mining, the condition of the mines, the condition of the rock above the mines, and then use analytical techniques to assess the probability of future subsidence. We design remedial measures to protect and mitigate damage to structures that will move and settle when long-wall mining passes under an existing structure. GAI designs treatments to protect structures from damage due to mine subsidence including grouting, deep foundations through the mine, overexcavation and backfill of the mine, deep dynamic compaction, and other possible treatments. We also perform post-damage movement evaluations to determine if the movement was the result of mine subsidence, and design remedial measures to stabilize and repair the structures damaged by mine subsidence.

Subsidence Studies and Remediation Projects 

GAI provides services in the area of vibration and seismic analysis of structures. The services include vibration and seismic analysis, noise and vibration problem design and mitigation, load and stress determinations, failure investigations, theoretical and experimental stress analysis, soil-structure interaction, analysis and simulation software development, structural reliability studies, finite element analyses, construction plans and specifications, and instrumentation and testing.

Vibration, Seismic, and Structural Reliability Projects