Tunnels:
  • Geotechnical investigations
  • Design of soil/rock tunnels
  • Constructability evaluations
  • Groundwater control systems
  • Instrumentation/monitoring
  • Changed conditions claims evaluation


Deep Excavations:
  • Design of braced excavations
  • Design of sinking caissons
  • Access shafts to existing tunnels
  • Instrumentation/evaluation
  • Value engineering design


Specialty Services:
  • Pre-construction surveys
  • Underwater inspection
  • Underpinning design
  • Grouting programs
  • Condition surveys of existing facilities
  • Repair of damaged or distressed facilities

NTH’s Value Added
Our 38 years of underground engineering experience, and hundreds of project successes, enable us to provide high-quality underground engineering services to our clients.

Underground Engineering Services

A Core Strength

Underground engineering, including design and construction of new facilities and
repair of existing facilities, requires in-depth, specialized knowledge and years of
experience to deliver successful projects.
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Underground engineering continues to be one of NTH's core strengths.
NTH professionals have designed tunnels and other underground projects, provided
field engineering during construction, investigated failures of underground facilities
both during and after construction, and repaired damaged facilities.

Over the past 38 years, we have worked on hundreds of underground projects
throughout North America. Much of our early work focused on helping contractors
deal with difficult ground conditions and failures during construction. This experience
has provided us with a greater understanding of how soils, rock and groundwater
behave when they are encountered in a tunnel or a deep excavation. In recent years,
we have worked with property owners, either designing new underground facilities or
repairing their existing infrastructure. Regardless of the client or the project stage, the
key to a successful project has always been, and will continue to be, constructability.
NTH knows what must be done to assure a constructible project.

Some of the underground engineering services we regularly provide include:

  • Design of earth support systems
  • Design of groundwater control systems
  • Value engineering of underground project designs
  • Instrumentation of underground facilities
  • Dispute resolution regarding underground construction
  • Inspection/evaluation of existing underground facilities
  • Design of tunnel lining system
  • Design of large and small underground civil works
  • Design for emergency repair of tunnels and other underground facilities