Tunnel Engineering

Designing and constructing tunnels present some of the most formidable challenges in the field of geoengineering. Our engineers and geologists are not only experienced designers, but several of them previously worked in the construction of tunnels and other underground structures. Thus we are well positioned to provide practical tunnel designs that minimize your risks and reduce construction costs. Our collaborative, multidisciplinary approach enables us to meet the complex technical challenges that tunnel design presents, as well as to apply that to multiple tunnel types such as for transportation, water and wastewater, and hydroelectric projects.

While constructability and function are key aspects of our design process, we also are responsive to the increasing demands of different project delivery methods. We work well with owners, other designers, and contractors to provide integrated, timely, and cost-effective solutions under various project delivery approaches. We are not only tunnel experts, but skilled project managers and strong contributors to project teams.

Our tunneling solutions include:

For Owners and Engineering Teams

  • Geotechnical evaluations for underground projects
  • Feasibility studies, evaluation of alternatives
  • Coordinated detailed design calculations, drawings, specifications, and geotechnical contract documents for tunnels, shafts, and geotechnical instrumentation
  • Cost estimates based on experience as contractors
  • Management of risk factors in design and construction
  • Construction management
  • Inspection and rehabilitation designs for existing tunnels
  • Emergency response problem analysis and remedial action plan/design
  • Claims review and cost analysis, expert witness work

For Contractors

  • Pre-bid evaluation of geotechnical bid documents and contract specifications
  • Tunnel support design and submittals
  • Excavation support design and submittals
  • Geotechnical instrumentation design and submittals
  • Value engineering change proposals
  • Claims support

Tunnel Engineering

  • Siting and feasibility studies, including geotechnical exploration and lab testing programs
  • Preliminary and final design
  • Initial ground support for tunnels and shafts
  • SEM/NATM design
  • Precast concrete segmental lining
  • Grouting and ground improvement design
  • Numerical modeling
  • Preparation of contract documents (plans, specs, GDMs and GBRs)

Constructability & Cost Estimating

  • Evaluation of designs for constructability
  • Estimates at all project development stages based on contractor experience
  • Bid or bid-check estimates for contractors using HCSS HeavyBid software

Risk Management

  • Risk register development
  • Qualitative risk analysis
  • Mitigation measure tracking and verification
  • Probabilistic quantitative analyses of cost and schedule impacts
  • Budget and schedule contingency analysis

Construction Engineering

  • Pre-bid geotechnical and contract document evaluations
  • Cost estimating
  • Excavation staging and support design
  • Tunnel and shaft design
  • Ground modification design
  • Value engineering
  • Geotechnical instrumentation and monitoring
  • Structural geologic mapping/evaluation
  • Claims analysis and support

Construction Management

  • Contract management
  • Construction inspection
  • Resident engineer services
  • Submittal review
  • Construction claims analysis

Trenchless Technology

  • Selection of trenchless methods and equipment
  • Assessment/characterization of geotechnical conditions
  • Jacking/receiving pit design
  • Geotechnical contract documentation preparation

Inspection and Rehabilitation

  • Facility inspection
  • Evaluation of existing ground support and structure
  • Evaluation of existing geotechnical and groundwater conditions
  • Preparation of rehabilitation design alternatives
  • Development of re-entry safety and ventilation procedures