Canada rewards national achievements 26 Oct 2017

Caverns of awesome scale and excavations for construction of the central underground section of the Confederation Line of the Ottawa LRT network won the project the top honours for the 2017 Annual Awards by the Tunnelling Association of Canada (TAC). It was the SEM mined excavation of the 2.5km twin track running tunnel route and its three underground stations that secured the construction contract project for the Rideau Transit Group (RTG) led by ACS Infrastructure of Spain, with Dragados and SNC-Lavalin as the main construction partners, and a team of consulting and design engineers that includes Hatch and Dr Sauer & Partners, and system operator Veolia Transportation.

The Can$1.2 billion fixed-price design-build-finance-and-maintain contract was awarded in December 2012 and all excavation was completed in February 2017.

Ottawa Confederation Line wins top award

Nomination of the project for the TAC 2017 Infrastructure Project of the Year Award recognises management of the construction and excavation effort to avoid disruption of the daily routine of the commercial city centre of the Canadian capital city during the years of construction. Rather than the more usual open-cut station boxes and jobs sites at each and along the route for advancing tunnelling works, all excavation of the 2.5km route and the three central LRT stations was advanced and managed from only three access points – the two transition portal ramps and an intermediate ventilation shaft excavation.

The mined alternative for the three station caverns greatly reduced the impact of the project on the city streets and brought with it additional advantages. It greatly reduced the need for near-surface utility relocations; avoided inconvenience and commercial losses by the businesses and offices along the route and greatly reduced the carbon footprint of the heavier construction effort of the original open-cut design for each underground station. The project is a model of how the mined underground stations cavern option is possible and by far more beneficial and respectful of the city centres under which metros and LRT systems must run.

Hydro challenge required innovation

The project is also a shortlisted finalist for the 2017 session of Brunel Awards of the ITA - International Tunnelling and Underground Space Association. ITA Awards winners will be announced and presented with their Brunel trophies and certificates at the gala dinner in association with the AFTES conference in Paris in November.

The 2017 Canadian Innovation Project of the Year was presented to the Upper Lillooet Run of River Hydroelectric Project in British Columbia. Excavation of the 2.5km intake tunnel passed through complex volcanic ground conditions that required particular excavation techniques to progress successfully through a zone of a loose, water bearing pumice. These included a cover of consolidation grouting followed by pipe umbrella crown pre-support. Another innovation on the project is application of poly-fibre reinforced shotcrete as a final lining in the waterway where required. The Award is presented to Golder Associates and CRT-ebc who completed the challenging excavation project for the Boulder Creek Power Limited Partnership.

A life long career recognised

For its Canadian Lifetime Achievement Award, TAC honours one of its favoured tunnelling engineers, Boro Lukajic. During a career of more than 45 years Lukajic has worked on many landmark tunnelling projects in Canada, the USA and Latin America. He was President of TAC from 1994-1998 and continues to contribute to the activities of the Association. As well as many published papers, Lukajic also lectures at universities and is a Fellow of the Engineering Institute of Canada. His award is well earned and deserved.

The Dan Eisenstein Memorial Scholarship to support the education of new tunnelling engineers and professionals in Canada was presented this year to Tim Pachalak who is completing his Master’s Degree at Queens University and ahead of advancing his career in underground construction engineering.

Rounding off the Awards for 2017, the Photo of the Year competition was won by Giuseppe Gaspari of Geodata Italy and for his outstanding 3D shot of the underground excavation works for the Ottawa LRT Confederation Line. The photo conveys the impressive excavation size and construction of the caverns and tunnels. The detail of the photo is further enhanced by viewing in the sphereviewer software.

As the recipients of the 2017 series of Awards enjoy their recognition, TAC will invite nominations for the 2018 series early next year.