EOSC 547 · Tunneling and Underground Engineering
Tunnelling methods (sequential excavation, NATM, TBMs). Influence of geological factors (rock and soil), design of ground support, and use of geotechnical instrumentation and numerical analyses for tunnelling projects. Case histories.
Why is the Gotthard Basetunnel several billion dollars over budget? Boston’s Big Dig also experienced cost over runs in the billions, with Niagara Falls and the Seymour-Capilano Twin Tunnels (in our own backyard) being plagued by delays and cost over runs in the tens to hundreds of millions. These cases demonstrate the immense technological challenges faced by engineers to meet societal demands while meeting certain economic, environmental and safety concerns. Most of these challenges relate to geological uncertainty and complex coupled processes.
With increasing tunnelling activity in the Pacific northwest (as well as internationally), this course will provide a historical background to tunnelling activities, the lessons learnt and future societal needs, which are calling for ever-more challenging designs. We’ll examine the different principles, approaches, and tools used in tunnel excavation and underground design. The examples and case histories reviewed will focus on tunnel excavations in both hard rock and soft soil.
The topics we’ll examine will step through the tunnel design process, from the writing and review of geotechnical baseline reports, to tunnelling methods for different ground conditions, to support design. Students will be exposed to state-of-the-art computer-based tools through assigned exercises and term projects - tools that reflect the ever-increasing complexity required by the challenging conditions being designed for.
Topic 1 - Historical overview
- The great alpine rail tunnels & tunnelling under the Thames
- Geological hazards in tunnelling (lessons learned)
Topic 2 - Tunnelling methods
- Sequential vs. full-face
- Tunnel boring machines
Topic 3 - Use of instrumentation
- Stand-up time & convergence
- New Austrian Tunnelling Method (NATM)
Topic 4 - Ground response & support interaction curves
Topic 5 - Stress- & strain-controlled failure
- Squeezing ground
- Spalling & rock bursting
Topic 6 - Groundwater & tunnelling
- Tunnel-induced subsidence
Topic 7 - Case histories