Schnabel and SWS

have decided to seek opportunities together on infrastructure and underground projects in the United States, to offer the market the strength of their combined resources and experiences. This alliance will provide state-of-the-art site investigation, design, value engineering and construction management services for underground transportation and water projects throughout North America.

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Our staff provides a diversified blend of skills under one corporate roof. We combine our expertise in the design and construction of underground structures with a keen understanding of the nuances and interrelationship of geology, hydrogeology, and geotechnics on underground projects.

Tunnel Design: Analysis of construction methods and support systems appropriate for given ground conditions; mechanized and conventional tunneling methods; NATM/SEM; rock bolt, shotcrete, lattice girder, liner plate, and rib and board initial support; cast-in-place and precast concrete segmental linings.

Shaft Design: Initial support and final lining design for shafts in soil or rock, including steel sheet piling, soldier piles, steel ribs and lagging or liner plate; diaphragm walls, with tiebacks if required; tangent or secant pile shafts; ground improvement methods; rock bolts, shotcrete, wire mesh, and lattice girders.

Cavern Design: Ground support design for large underground openings such as transit platforms and escalators, tunnel intersections, and underground powerhouse facilities.

Geostructural Design: Soil and rock cut slopes for tunnels, underground openings, rail, highways, cofferdams, bulkheads, bridges, support of excavation and leaders in micropile and soil nail wall design.

Structural Geology Evaluation: Analysis of rock mass data to identify critical joint set orientations and their intersections, and kinematic analysis to identify critical wedge failure patterns and required ground support systems.

Numerical Methods for Design: Finite element and finite difference methods for determination of stress and deformation around underground openings, and for evaluation of excavation sequencing and phasing impacts on ground response and structural support.

Inspection and Rehabilitation: Inspection of vehicular, rail, hydroelectric and pedestrian tunnels and underground chambers for fitness-for-service and/or rehabilitation.

Risk Management: Systematic identification and evaluation of risk issues that can affect project cost, schedule, and safety; development and tracking of risk mitigation measures to effectively manage and reduce the likelihood and impact of risk events.


Schnabel and SWS have decades of experience on projects of all sizes and levels of complexity, all over the world. We share a passion for our work, a focus on developing innovative solutions and a commitment to on-going improvement. Some of our projects are illustrated here on this page.

Snettisham Crater & Long Lake Tunnel Inspections Juneau, AK USA

Lake Dorothy Hydroelectric Project
Juneau, AK USA

Domestic APM Tunnel & East Tug Tunnel
Dulles Airport, VA USA

DC Clean Rivers
Washington, DC USA

Plateau Creek Pipelines Tunnel Project
Grand Junction, AK USA

DART Transit Tunnel NC-1B and CityPlace Station
Dallas, TX USA

Catania Metro
Catania, ITALY

HSR Underground Link in Florence
Florence, ITALY

Grand Paris Metro

Frankfurt Airport
Frankfurt, GERMANY

Brenner Base Tunnel

T4 Frejus Highway Tunnel


Schnabel Engineering

Schnabel is a trusted partner in building the foundation for project success. We provide specialized expertise and design for geotechnical, tunnel, and dam engineering projects across the U.S. and worldwide. As an entrepreneurial, employee-owned company of over 300 diverse professionals, we have a passion for client service and tough technical challenges. An ENR Top 250 engineering firm, Schnabel serves both public- and private-sector clients.


SWS Engineering

SWS is an engineering company active in infrastructure construction. We are part of the SWS Group and offer specialist engineering, project management and risk management services. For more than thirty years, we have been helping clients build infrastructures that form the backbone of local communities. We are committed to service quality and on-time delivery. We are firmly convinced of the importance of designing and building works with a sustainable economic, environmental and social footprint.


Call us today at +1 972-250-3322 or write us at