ROTATED-ELLIPSE ARCH PEDESTRIAN BRIDGE FOR THE CALGARY WEST LIGHT RAIL TRANSIT EXTENSION PROJECT

摘要

As part of the Calgary West Light Rail Transit (LRT) project, the existing pedestrian overpass crossing Bow Trail SW, west of 24th Street SW, was replaced to provide a widened roadway and LRT right-of-way. An increase in vertical clearance was also necessary for the LRT power propulsion system catenary wires. The project-wide architectural concept of a rotated ellipse was incorporated into the bridge design through the ellipse shaped arches with the pipe components rotated by 10 degrees. The two pipe arches were also inclined inwards to further enhance the aesthetics. The bridge utilizes pipe arch as the main structural members, providing a main span length of over 50 m and a top-of-arch height of approximately 16m. The north abutment continues the elliptical theme by carrying the curve design through the exposed portion of the arch foundation wall. This paper presents the opportunities and challenges experienced throughout design, fabrication, erection and construction. The design had a focus on engineering solutions developed by the design-build team to minimize potential risks during construction.