INNOVATION May-June 2017

High bluff overlooking Trans-Canada Highway stabilized

slopes at a high rock bluff. The instability led to a tailored rock-bolting solution. Significant unstable rock masses on the slope required trim blasting and rock fall protection by means of netting and a catch fence. Challenging soil conditions, combined with water springs, were also found and remediated through innovative construction techniques. The expanded highway was opened in late- December 2016.

As part of BC Ministry of Transportation and Infrastructure’s progressive upgrade and expansion of the Trans-Canada Highway, Tetra Tech Canada served as the geotechnical engineers of record at Hoffman’s Bluff, near Chase, BC. Following investigation and an optimized design that includes retaining structures, catchment ditches, and rock and soil cut slopes, construction began in 2014. A key challenge was the identified kinematic planar instability of the planned rock cut

Iconic New York City building draws on bridge-construction expertise

The World Trade Center Transportation Hub, known as the Oculus, is the new transportation hub at the tip of Manhattan Island, in New York City, and serves more than 200,000 commuters daily. The structure’s design is inspired by a pair of hands releasing a white dove, which made it extremely complicated to build. The design pushed architectural and structural limits, and required innovative erection engineering for its successful construction. Buckland and Taylor International, Inc. (an affiliate of COWI North America, Inc.) was selected as the Erection Engineer. Buckland and Taylor’s engineers erected the structure’s arches segment by segment, using the free cantilever segmental construction method commonly applied in bridge erection. The method saved time and money by reducing the amount of falsework needed, and allowed the geometry of the structure to be monitored and adjusted throughout construction. APEGBC members: Dr. Tobias Petschke, P.Eng., Darryl Matson, P.Eng., Nedim Alca, P.Eng., Tom Surtees, P.Eng.

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