Foundation Engineering completed a geotechnical investigation of the Fibre Way Bridge in the Port of Longview industrial area of Cowlitz County, Washington. The purpose of the investigation was to observe the conditions below the distressed portion of the approach panel at the north abutment of the bridge and to provide an approach to the repair of the panel.
The bridge was constructed by the Port of Longview to provide access over a set of railroad tracks for the Port’s industrial area. The bridge is supported on ±30‑foot high abutment walls founded on piles driven to dense sand or gravel alluvium. The bridge approaches are supported on ±25-foot tall retaining walls with Geofoam backfill intended to reduce the load and settlement. The approach panel is supported on a 10‑inch wide corbel that is structurally connected to the abutment wall and bridge deck.
The investigation included a review of the original bridge plans, Geotechnical Report prepared by another consultant, and an approach panel edge detail. Field work included site reconnaissance and two, 12-inch diameter cores through the approach panels on the north abutment. Foundation Engineering provided conclusions concerning the cause of the observed cracking of the panels and possible mitigation options.