GEOLOGICAL ENGINEERING is a unique discipline that brings together many classical fundamentals of engineering with a firm foundation of geological knowledge and skills. This is important in tunnelling as the number one cause of cost overruns, delays and general tunnelling risk is undoubtedly the complexity and often underappreciated nature of the tunnelground interaction and the role that geological properties and processes play in this process. Managing "geo-risk" by forecasting problems to be encountered in tunnelling, reducing uncertainties prior to and during construction, and coping with inescapable geological challenges through excavation and support design is a critical outcome of "thinking Geo", a major outcome of Geological Engineering education.
Queen’s University has one of Canada’s few Geological Engineering Undergraduate Programs. Other notable programs exist at the Universities of New Brunswick, British Columbia and Saskatchewan as well as the University of Waterloo. Francophone programs thrive at École Polytechnique, Université Laval and Université du Québec à Chicoutimi. Established and focussed graduate programs in Geological Engineering exist at Queen’s, British Columbia and Saskatchewan. Related graduate programs can also be found at Simon Fraser University, as well as the University of Alberta and the University of Toronto.
At Queen’s, Geological Engineering is a diverse program that covers aspects of geotechnical engineering, geoenvironmental engineering, applied geophysics and resource engineering. In this article, the focus is on geotechnical engineering and specifically, underground construction.
Engineering undergraduates at Queen’s begin with a common first year covering the basic fundamentals we can all remember (or not!), including maths, physics, chemistry, programming, and introduction to design. Queen’s is unique in that first year engineers also undertake a course in Earth Systems Engineering in which they learn about the interaction between all fields of engineering and Earth materials and Earth processes. This includes obvious connections such as resource formation and recovery, natural hazards, and construction, but also raises awareness of the importance of lesser known resources, such as rare Earth elements and lithium, which our modern electronics driven lifestyle could not do without. The use of underground space is highlighted in this course.
As the undergraduate geological engineers move into second year, their immersion in Earth science begins in earnest while at the same time learning about economics, mining engineering, tunnelling, geophysics and resource exploration and environmental management. Field education begins at the beginning of second year and carries through until graduation. Here the students learn a multitude of site investigation skills, both old-school and state-of-the-art. Self-direction is balanced with teamwork to enhance the professional value of our students. Throughout third year the geological focus gives way to applied engineering applications where engineering analysis plays an ever-increasing role in their academics.
By the beginning of fourth year the students are ready to tackle complex engineering problems in their capstone design course. In terms of experience and skills related to tunnelling and underground construction, Queen’s geological engineers are introduced to this field early in second year, through core course and electives in Rock and Soil Mechanics (fundamentals), Geotechnical Engineering (analysis and design) and finally in the fourth year Geological Engineering Field School and in their Advanced Engineering Geology and Rock Engineering Design course. Field trips to active mining and tunnelling projects round out this exposure.
The graduate program in Geological Engineering at Queen’s is also diverse in scope. Approximately 70 per cent of the graduates in this program work in areas related to tunnelling, mining or deep repository construction. Tunnelling research and education at the graduate level has been a major focus of the Queen’s Geomechanics Group since 2002. Led by professors Mark Diederichs, Jean Hutchinson and Nicholas Vlachopoulos, this graduate research group has seen more than 60 Graduate Program alumni undertake and complete high impact engineering research and head off to successful careers in industry, consulting and academia. The fundamental focus of the graduate work here is on characterisation of geomaterials, the complex interactions of geological structure and underground development, quantification of geo-risk, rock mechanics for mining, tunnelling and nuclear waste repository development, and support design for underground excavations.
Typical research projects are industry driven but contain both fundamental mechanics as well as practical engineering components. The goal is always to advance the state-of-theart while remaining sensitive to the immediate needs and practical engineering constraints and priorities of modern tunnelling, mining and underground construction. Graduate researchers typically work through a program of investigation, analysis and interpretation that includes the generation of raw data, either in the field, the lab, or both. This data can take the form of measurable parameters, empirical assessments, qualitative observations, usually in combination. The work often progresses to advanced simulation and or analysis using state-of-the-art computer tools for 3D imaging, virtual characterisation, change detection, numerical back analysis or forward modelling. Case study verification then follows to round out the work. Students normally engage in their own technology transfer by presenting at conferences, working with industry supporters directly or through workshops and by publishing journal articles summarising their contributions. Both the group’s focus and the diversity of projects related to tunnelling, mine development and underground construction, are highlighted below in a partial listing of past and present graduate research projects (PhD and Masters) at Queen’s University:
¦ Urban tunnelling – Construction method selection process optimization
¦ High resolution monitoring of multiaxial tunnel support response
¦ Time dependent behaviour models for tunnel response
¦ Rockmass strength evaluation for underground construction in complex heterogeneous rocks
¦ Updated core logging procedures to improve rock behaviour prediction for deep excavation
¦ Numerical analysis of excavation damage zone fracture for Deep Geological Repository design
¦ Discrete fracture network models and excavation stability for tunnels and caverns
¦ Engineering analysis and optimization of near face tunnel support
¦ Development of a new post-yield dilation model for rocks for use in tunnelling and mining
¦ Tunnel boring machine simulation in brittle ground (Brenner Tunnel)
¦ Reliability analysis for tunnel support Design
¦ Three dimensional tunnel response in weak tectonized ground (Egnatia Project, Greece)
¦ Engineering geomechanics of hard rock TBM performance (Gotthard & Loetchberg Tunnels)
¦ Rock damage prediction and impact on tunnel, cavern and shaft design ¦ Lidar point cloud analysis for change detection in tunnels
¦ Engineering geology and performance (Niagara Beck Tunnel, Ontario)
¦ Behavioural uncertainty and contract risk for tunneling
¦ Support analysis and design in squeezing conditions (Yacambu- Quibor Tunnel, Venezuela)
¦ Modelling of shear behaviour for tunnel rockbolts
¦ Influence of heterogeneity on tunnel stability (St Martin la Porte Tunnel, France)
¦ Optimised field testing and numerical simulation of shotcrete tunnel support
¦ Lidar for rockmass characterization in active tunnels (Sandvika Tunnel, Norway)
¦ A rock-system approach to engineering classification for mine development
The research group has active collaborations with many Canadian institutions including the Universities of British Columbia, Alberta, Toronto, Saskatchewan as well as Laurentian University, Waterloo and McGill. Internationally, collaborations include the University of Vigo (Spain), ETH in Zurich (Switzerland), National Technical University of Athens (Greece), Politecnico Torino (Italy), University of Bologna (Italy), University of Brasilia (Brazil) and the Norwegian Geotechnical Institute, among others. This collaboration is essential to maintain a global perspective in the scientific arena.
Practical perspective is achieved through an encouragement for students to present their work at international conferences including the World Tunnel Congress (WTC), Eurock (European rock mechanics conference), International Society for Rock Mechanics Congresses and the American Rock Mechanics Association Conference. Nationally, the students gain exposure at Tunnelling Association of Canada (TAC) meetings as well as conferences and symposia hosted by the Canadian Geotechnical Society and Canadian Institute of Mining. Research is also presented at numerous other national and international specialty conferences, meetings that often include bit academic researchers and end users from industry. Graduate students are also encouraged to expand their knowledge and experience base by attending national and international workshops and short courses hosted by TAC, WTC and other organisations.
The research and development as well as the graduate training activities in the Geological Engineering Program at Queen’s University is enhanced by well-established linkages with the Civil Engineering and Mining Departments at Queen’s and the Civil Engineering Department at Royal Military College (RMC) across the river. Geological Engineering, together with these three departments, forms a powerful cluster of geotechnical research under the umbrella of the GeoEngineering Centre at Queen’s University and RMC. This group is a collective leader in underground geomechanics and is also world-renowned for, among other specialties, trenchless technology, HDD applications and buried infrastructure rehabilitation.
One of the most important components of the graduate experience at Queen’s University, and particularly in the Department of Geological Engineering is the ongoing emphasis on field exposure to active and or historically significant geotechnical projects. Over the last 10 years a number of major international field courses have given our students first-hand experience in geohazards, engineering geology, tunnelling and mining at legendary locations around the globe.
These educational tours, while organized by the group leaders, are effectively student-led in terms of technical content. Each site along the way is researched and analyzed by a graduate student who then leads the technical tour for that stop on the trip. The field courses typically merge engineering geology (including key aspects for tunneling such as tectonics), tunnel, mine, cavern and dam construction with critical aspects of design, including, but not limited to, geomechanics and logistics.
Example of previous field courses for Geological Engineering graduate students at Queen’s include:
¦ Tunnelling, Geohazards and Engineering Geology in Europe (2008, 2011, 2016)
This field course involved a two-and-a-half-week odyssey through Switzerland, Germany, Austria, Italy and France. Major project sites such as the Gotthard, Brenner and Ceneri tunnels were visited. In 2011 the group was able to inspect the newly assembled 15.5m diameter TBM being prepared to bore the Sparvo tunnel in Italy. On the other end of the time scale, a 2000-year-old and currently active iron mine (Gonzen) and quarry (Carrara) were explored. Numerous other bored, blasted and mechanically excavated tunnels were visited enroute as well as the sites of some of Europe’s most notorious engineering disasters including the Vaiont and Malpasset dams. This trip has also included a technical tour of the Herrenknecht TBM design offices and factory in Schwanau, Germany.
¦ Engineering Geology and Tunnelling in Greece (2011, 2013, 2015)
This two-week course runs in collaboration with the National Technical University of Athens and exposes Queen’s students to challenging tunnel projects from Athens to the north of Greece and from coast to coast.
¦ Mining, Geological Engineering and Tectonics, South West USA (alternate years including 2015)
This two- to three-week field course has been running for nearly two decades and traverses Colorado, Utah, New Mexico, Nevada, Arizona and California. The focus is on mining and tectonics.
¦ Tectonics and Engineering Geology, Nepal (2012) This unique graduate excursion to the Himalaya of Nepal (Khali Ghandaki region) included focus on tectonics, infrastructure challenges and hydroelectric potential.
¦ Mining and Engineering Geology, Chile and Bolivia (2014)
This recent, three-week trip exposed the students to some of the largest and most productive mines in the world (northern Chile) and then brought them into the contrast of very primitive mining environments in the highlands of Bolivia. While the focus was on Andean tectonics here, the technological challenges of underground development were discussed in the context of these projects.
All of these intensive field experiences depend almost entirely on the willingness of project leaders and site personnel to allow a group of local or foreign students to visit these active projects and to engage in discussions with informed personnel on site.
In addition to these field courses, the group is always prepared to take advantage of opportunities to visit and learn from local tunnelling projects such as the recently completed Niagara Beck project, tunnelling in Toronto or Ottawa or experience opportunities in the mining community. There is, of course, the same critical reliance on project management and operations to allow these visits and to contribute to these essential learning experiences.
These field experiences are a significant part of the educational package at Queen’s and provide graduates with a breadth of exposure to compliment the depth of engineering knowledge they gain from their own research and from their subsequent employment.
Tunnelling education is important for Canada. Queen’s Geological Engineering, with its internal, Canadian and International collaborators, has made this a major priority at the graduate level as well as including fundamentals, applications and skills, important to the tunnelling industry, within the undergraduate teaching curriculum.
This level of commitment to tunnelling education is not possible solely within the constraints and structure of an isolated University setting. It relies on the technical input to teaching and research, active involvement in projects and ideally financial support from all players within the tunnelling, construction and mining industries.
Queen’s acknowledges past support and welcomes future collaborations with industry partners, whether suppliers, designers, constructors or consultants. University groups such as that at Queen’s and Royal Military College (and other institutions mentioned earlier) are a critical component of the tunnelling education network in this country, but more intensive interaction between universities and industry stakeholders is critical for mutual success.
