D'Appolonia is a client-focused provider of consulting engineering services. Since the founding of the firm in 1956, we have provided engineering, scientific and construction-related services to industrial and governmental clients in the U.S. and in many foreign countries. Our core capabilities include civil, geotechnical, and environmental engineering; geology and geophysics; and hydrology and hydraulics. These capabilities have been applied to a wide range of projects, as listed below.

Markets That We Serve
D'Appolonia provides a broad spectrum of technical services. Our primary service areas include the following:

Project Locations
D'Appolonia has successfully completed projects throughout the U.S. and overseas. D'Appolonia currently has active projects in South America, Africa, Asia and the Middle East. Through our association with Dynamic Power Technologies (DPT) and D'Appolonia, S.p.A. (based in Genoa, Italy) we are involved in interesting and challenging projects worldwide.



site exploration, subsurface exploration, tunnels, soil slopes, rock embankments, alternatives evaluation, value engineering, value engineering studies, bridge piers, bridge pier foundations, highway cuts and fills, cut and cover, braced excavations, anchored retaining walls, geosynthetics, design review, constructability evaluation, retaining wlls, cuverts, stream bank stabilization, loess bluffs, soil nails micropiles, MSE walls, mechanically stabilized earth walls, RSS, reinforced soil slopes, roadway design, soldier beams, lagging, tangent caisson walls, soil mixing, foundation improvement site reconnaissance, site exploration, demolition, demolition plans, stormwater management, storm water management, hydrology, design basis flood, hydraulics, hydraulic engineering, channel flow, flood studies, erosion and sedimentation control, erosion and sedimentation control plans, site layout, site grading, site grading plan, grading plan, cut and fill, balanced cut and fill, grading plan preparation, roadways, roadway design, parking lots, parking lot design, site utilities, site utility design, water, sewer, electrical, electric, permitting, regulatory approval, regulatory interaction, cost estimation, cost development, scheduling, schedule preparation, bid package preparation, contractor selection, bid evaluation, funding assistance siting studies, seismic design criteria, foundation design, waste facility design, flyash, remedial design, nuclear power plants, cogeneration plants, regional geology, local geology, seismology, underpinning, equipment foundations, scrubber residue, aqueous wastes, tailings slurry, permitting, foundation design, equipment foundations, turbine foundations, driven piles, drilled shafts, micropiles, Operating Basis Earthquake, OBE, Safe Shutdown Earthquake, SSE, Probable Maximum Flood, PMF, OEMs, Dynamic Power Technology, DPT, IPPs, Independent Power Producers, power industry foundation design, soil nails, soil-nailed slopes, soil-nailed embankments, reinforced soil slopes, RSS, reteining walls, sheet pile walls, anchored reteining walls, anchored sheet pile walls, mechanically stabilized earth embankments, MSE, MSE embankments, problem ground conditions, geosynthetics, expansive soils, expansive materials, expansive shale, expansive slag, foundation heave, slope design, slope failure, slope failure remediation, landslides, landslide remediation, specialty geotechnical construction, drilled shaft, driven piles, micropiles, foundation improvement, karst, karst terrain, compressible soil, dynamic compaction, grouting, soil mixing, subway system, subway tunnels, braced excavations, underpinning, settlement, bearing capacity, minipiles, pin piles, obstructions, spread footings, mat foundations, stone columns, vibro-compaction, wick drains, soldier beams, lagging, filter fabric, geomembrane, geocomposite drains, synthetic liners, site exploration, drilling, soil sampling, landfill design, landfill closure, geogrids, geogrid reinforced slope, deep foundations, slope stability analysis, bearing capacity analysis mine waste management, coal refuse disposal facilities, coal refuse disposal impoundment, mine site reclamation, mine site abandonment, reclamation plan preparation, tailings dams, tailings impoundments, internal drains, liquefaction, upstream construction, mine subsidence, mine subsidence evaluation, longwall mine subsidence, slurry impoundments, slurry impoundment design, mine seals, deeply buried conduits, deeply buried pipes, deeply buried flexible conduits, deeply buried flexible pipes, breakthrough potential, breakthrough potential evaluation, mine infrastructure, conveyors, mine drainage abatement, mine drainage treatment, staged construction, permitting, coal, limestone, silica, copper, silver, gold, uranium, mining, bio-solids, site grading plan, erosion and sedimentation control, stormwater management, angle of draw, surface monitoring, surface instrumentation, seepage, seepage control, HDPE pipe, flowable backfill, pozzolan, deeply buried plastic pipe, AMD, AMD treatment, acid mine drainage, acid mine drainage treatment, pumping systems, MSHA Coal Refuse Design Manual forensic engineering, forensic studies, expert engineering studies, expert engineering testimony, expert testimony, construction claims, construction disputes, structural failure, landslide, foundation movement, embankment failure, settlement, failed slope, subsidence, redesign, remedial design, changed conditions, stability analysis, instrumentation, differential movement, differential settlement, foundation settlement, blast damage, trial testimony, structural damage dam inspection, FERC, FERC Part 12 inspection, FERC Part 12 facilitation, failure modes analysis, dam breach analysis, flood studies, flood routing, hydrology, design basis flood, probable maximum flood, PMF, Emergency Action Plans, EAP, instrumentation, dam instrumentation, drainage, seepage, seepage control, slope failure, earth embankment dam, concrete gravity dam, shoreline protection, reservoir, seismic analysis, seismic stability analysis, liquefaction, liquefaction analysis, soil liquefaction, hydraulics, hydraulic engineering, spillway repair, hydraulic structures, hydraulic design, dam rehabilitation, armoring, automated monitoring systems, HEC-1, HEC-RAS, Operations and Maintenance Manual, O&M Manual, remedial design, construction monitoring, probable maximum precipitation, PMP, crest raising environmental site assessments, environmental impact statements, Superfund sites, Brownfield site remediation, landfill design, landfill closure, solid waste management plans, environmental compliance monitoring, underground storage tanks, UST, work plans, health and safety plans, QA/QC plans borehole logging, cross-hole surveys, DC resistivity, electromagnetics, EM, TDEM, gravity, ground penetrating radar, GPR, induced polarization, seismic reflection, seismic refraction, archaeology, abandoned mine workings, contaminant plume, environmental site characterization, burial plots, buried foundations, artifacts, geophysics, geophysical methods, geophysical techniques geohazard assessment, blasting plans, blast monitoring, vibration monitoring, seismic hazard assessment, fault studies, soil dynamics, rock dynamics, earthquake resistant design, seismograph, soil-structure interaction, dynamic response, fault studies, geology, seismology, remote sensing, GIS, land use, land cover, vegetation health, tree canopy health, agricultural practices, water qualtiy, urbanization, thermal sensing, LIDAR, longwall mine subsidence, ground truthing, stressed tree canopy, multispectral scanning, subsidence analysis, Landsat, SPOT, Secchi depth, turbidity, TSI manuals of practice, technical course preparation, technical course presentation, applied research, innovative technologies, earth retaining systems, non-destructive testing, design manuals, LRFD courses, LRFD, Coal Refuse Disposal Manual, MSHA, AASHTO, bridges, highway bridges, driven piles, drilled shafts, retaining walls, piers, abutments, GPR, flyash codisposal, geophysics