Lewis & Clark Pedestrian Bridge

The Lewis & Clark Pedestrian Bridge replaced an existing bridge which had four interior supports that were all located within the environmental zone, and on soil that was determined to be insufficient for support of the new bridge. New bridge supports were required to be supported on deep foundation elements. Because of this constraint, it was determined that a 190 foot clear span bridge would be the best option for minimizing the impact to the environmental zone. The clear span option also allowed for ease of construction, as getting equipment and materials into the ravine for new interior foundation elements would have been challenging. To accommodate the limited construction access and geotechnical constraints of the site, grouted micropiles were selected for support of the abutments. The smaller diameter micropiles allowed for relatively light installation equipment to be safely used on the steep slope of the ravine.