This paper presents the innovative erection techniques that were developed and successfully executed to erect three recent steel bridges in Canada. The three bridges presented are: Progressive Cantilever Erection of the 199A St. Viaduct, Golden Ears Project, BC, Canada; Incremental Launching of the Athabasca River Bridge, Ft. McMurray, AB, Canada; The Transverse Launching of the Mount Hunter Creek Bridge, Golden, BC, Canada. The tightly curved main span alignment of the 199A Viaduct crosses active railway lines and the South Approach Viaduct. The site constraints in the main-span precluded erection of a plate girder system through conventional method using cranes. A feasible erection methodology was developed using a progressive cantilever method that required the use of a torsionally stiff box girder system. The transverse launch employed for Mount Hunter Creek accelerated the erection of structural steel, improved quality assurance, and increased safety for iron workers and inspectors. By pre-assembling the structural steel, all six girders were installed in a 72 hour period with less than 19 hours of combined closures to the Trans-Canada Highway. The steel erection of the new Athabasca Bridge proved that the old idea of launching the entire bridge superstructure is still a contemporary and cost effective construction method. The incremental launching technique contributes significantly to accelerated and safe bridge construction but requires a good understanding of construction and engineering tasks in general and in detail. For the covering abstract of this conference see ITRD number E220308.
Abstract