Proceedings - 13th International Workshop on Micropiles - 2017, Vancouver, BC, Canada, (ISM, DFI, ADSC)
Utilization of Micropiles at the Expansion of BMO Field, Toronto, Canada
Jim Bruce, P.Eng. Naresh Gurpersaud, M.A.Sc., P. Eng., Anojan Sivaloganathan, Daniel R. MacLean, P.Eng.
BMO Field is an outdoor stadium located on the shores of Lake Ontario in Toronto, Canada. It was opened in 2007. The venue was originally constructed for the Major League Soccer franchise, Toronto FC, but was expanded starting in 2014 to accommodate the Canadian Football League’s Toronto Argonauts in time for the kickoff to the 2016 season. From 2014 to 2016, a $120 million (CAD) renovation project was completed that included an 8,400-seat expansion, significant upgrades to the hospitality zones, and twin canopies that will keep most of the spectators under cover. The west canopy is founded on micropiles. The micropiling portion of the project consisted of the installation of 46 piles, with factored tension/compression loading as high as 3000 kN /4000 kN per micropile, all for support of new pile cap and grade beam foundations for the west canopy. Alignments range from vertical to 1:4 batters. Sizing and selection of micropile central reinforcement at this project was governed by EA as stipulated by the structural engineer, EAmin. This aspect, combined with the particularly deep rock sockets driven by the high magnitude uplift forces, led to a unique opportunity to forego full scale load testing. Micropiles were selected for this project due to severely restricted access at the west canopy column bases’ locations. The stadium’s existing infrastructure includes a state of the art SubAir system consisting of boilers and piping previously installed at the cost of several millions of dollars. The system heats (and, when necessary, drains) the soil below the playing surface, keeping the natural grass field healthy and happy regardless of the season or the weather. Selected portions of this system would have had to be demolished to accommodate conventional deep foundations, whereas the micropiles were able to be constructed from inside an existing utility closet with no modification to any aspect of the existing SubAir system infrastructure. This paper provides a detailed case history of this project, looking at the design of the micropiles, their installation and the QA/QC measures utilized.
|article #2649; publication #1033 (ISM- 2017)|