Tunnel and Shaft Design

Variable ground, groundwater, and site conditions are just a few factors that impact tunnel and shaft design. We conduct detailed ground characterization, site reconnaissance, and feasibility studies at project locations to determine the appropriate tunnel geometry, construction methods, and support systems, with cost estimates suitable for comparative evaluation of alternatives.

• Plans and specifications, design reports, geotechnical interpretive reports (GIR), geotechnical data reports (GDR), and geotechnical baseline reports (GBR)
• Preliminary and final liner tunnel design for highway, water supply, and sewer tunnels in rock and soil; tunneling methods including digger shields, roadheaders, conventional drill and blast, and main-beam and pressurized face TBMs
• Initial and final support design elements, including rock bolts, shotcrete, lattice girders, liner plate, ribs and boards, cast-in-place, and precast concrete segments
• NATM/SEM design and construction method, making use of the host material’s strength and deformation properties, controlled deformation, and reactive lining techniques to provide ground support in rock and soft ground tunnels
• Numerical methods for design; finite element (PLAXIS®) and finite difference (FLAC®) methods for determination of stress and deformation around underground openings
• Cavern support design for tunnel intersections, underground chambers, and powerhouses
• Shaft and back support design for hard rock and salt mines
• Tunnel inspection and rehabilitation of underground chambers and vehicular, rail, hydroelectric, and pedestrian tunnels
• Constructability review and analysis of probable cost prepared using contractor style cost estimating methods and software
• Risk assessment and management of planning, procurement, design, construction, and operational risks; development of strategies to mitigate cost and schedule impacts