Spectacular Use of DYWIDAG Systems: The Glacier Skywalk in Canada’s Jasper National Park
Since May 2014, Jasper National Park in Alberta, Canada, features a spectacular highlight for visitors: The Glacier Skywalk. The skywalk is a visitor platform with a glass floor on a steel frame structure that extends from a cliff at a height of 280m. The cantilevered platform was erected at an existing road and extends over 30m from the rock. It provides tourists with an impressive view of the Sunwapta Valley with its glacier fields and steep rock walls.
The viewing platform contains a draped cable in its inside radius. A large compression chord acts together with steel framing members to provide torsional resistance under partial load.
Tuned mass dampers in the walkway minimize vibrations caused by walking, and wind deflectors attached to the outer handrails reduce swinging caused by crosswinds.
The 30m long glass skywalk is supported by 600t of cantilevered, trapezoidal box girders secured onto tied back foundation blocks. The foundations were anchored in depths of 10 to 20m in the load-bearing rock using rock anchors. DSI Canada supplied 48 Ø 63mm DYWIDAG Rock Anchors for tying back the foundation blocks.
64 Ø 46mm GEWI® Micropiles and Ø 46mm double corrosion protected (DCP) DYWIDAG Rock Anchors were installed in the concrete foundations for the box girders. The concrete foundations were further post-tensioned with 77 Ø 46mm THREADBAR Tendons. The steel frame structure was secured to the concrete foundations using 80 post-tensioned Ø 36mm DYWIDAG Anchor Bolts. 2 Type 9-0.6" DYWIDAG Strand Tendons in steel ducts were used to support the cantilevered glass platform. DSI Canada provided technical assistance for all of the products that were supplied and also provided the equipment needed for tensioning the anchors. An experienced DSI technician supervised the construction work on site.
DSI worked closely with the design engineers and the general contractor from the beginning conceptual stage through to completion of the project. Due to the remote sub-alpine terrain, construction work was very difficult. The constrained site access prevented using cranes for the stressing. Scaffold sections had to be set up and manual chain falls had to be used to hoist equipment. This meant all materials and equipment had to be prepared ahead of moving the suspended structure into place, as the large lifting crane blocked any subsequent access to the jobsite.
Site conditions required quick design changes. In some cases, DSI had to produce and supply additional products just in time in order to make use of the short time frame in which the construction work could be carried out due to the extreme local weather conditions. Even before construction of the skywalk started in 2011, the project won the Future Projects Category at the World Architecture Festival in Barcelona.