DESCRIPTION: The City of Portland constructed three pedestrian bridges for the westward extension of the Springwater Corridor Bicycle/Pedestrian Trail. The bridges are located on an existing railroad embankment and span Johnson Creek, SE McLoughlin Boulevard and the UPRR tracks. Each bridge consists of a different type of structure: a two span steel deck girder at Johnson Creek, a steel pre-fabricated truss at UPRR, and a steel tied-arch over SE McLoughlin.
SERVICE: Foundation Engineering completed a geotechnical investigation or all three bridges. Each bridge is supported on pipe piles. The SE McLoughlin Boulevard Bridge has steel pipe arches tied at the deck level. This structure is self-stiffened, so no inclined foundation elements are required at the abutments to resist the thrust of the arch. Ground anchors were designed for uplift at the end bents. Installation of stability piling allowed tensioning of the ground anchors early in the construction sequence. In addition to the bridges, retaining walls were designed to provide access to the path from SE McLoughlin.