Tunnel and Shaft Design

Soft soil, different rock formations, wet conditions, and historical construction debris are just a few factors that impact tunnel and shaft design. We conduct detailed reconnaissance and feasibility studies on project sites to determine the appropriate tunnel geometry, construction methods, and support systems, with cost estimates suitable for comparative evaluation of alternatives.

• Construction documents/design reports, geotechnical interpretive reports (GIR), geotechnical data reports (GDR), geotechnical baseline reports (GBR), construction drawings, and specifications
• Rock and soft ground tunnels preliminary and final liner design for highway, water supply, and sewer tunnels in rock and in soil; tunneling methods including digger shields, conventional and pressurized face TBMs
• Initial and final support design rock bolts, shotcrete, lattice girders, liner plate, rib and board initial support, and cast-in-place and precast concrete final support liners
• NATM (New Austrian Tunneling Method) 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 design ground support in large underground openings such as pump chambers, tunnel intersections, and underground hydroelectric generating stations
• Mine engineering shaft and roof support design for hard rock and salt mines
• Tunnel inspection and rehabilitation inspection of vehicular, rail, hydroelectric, and pedestrian tunnels and underground chambers for fitness-for-service and/or rehabilitation
• Constructability review and cost estimating analysis of probable cost prepared using contractor style estimating methods and software
• Risk assessment and management evaluation of planning, procurement, design, construction, and operational risks; development of strategies to mitigate cost and schedule impacts