Abstract Manager

The Old Skeena River Bridge is a 9-span, 341 m long, single lane bridge consisting of 3 steel stringer approach spans, 5 steel deck truss spans, & a steel through truss span, crossing over the Skeena River in Terrace, BC. The structure opened on July 21, 1925, was realigned to accommodate a parallel railway bridge in 1953, & the timber deck was replaced with an open grate steel deck in 2001. The bridge was last recoated in the early 1980’s & still contained red-lead primer.

The project included: 1) Close proximity inspection with ropes & ladders (2017) & snooper truck (2021); 2) Load evaluation of trusses for verification of existing posted live load restrictions & ability to carry the Ministry snooper truck inspection vehicle; 3) Evaluation of construction lateral wind load capacity during enclosed coating operations; 4) Steel coating renewal considering various coating systems & methodologies (overcoat vs. removal & recoating) combined with LCCA of the different options; 5) Installation of 6 new sidewalk refuge bays to accommodate passing along the bridge; 6) Replacement of corroded steel roller bearings with sliding elastomeric bearings, including strengthening to facilitate bridge jacking operations for bearing replacement; & 7) Replacement or repair of severely corroded members & plates.

There were numerous challenges & lessons learned during the design & construction process, including: 1) Inspection access for truss bridges & what is an appropriate expenditure on inspection during the design process; 2) Responding to unanticipated conditions uncovered following sandblasting – more corrosion than expected including complete penetrations; 3) Design considerations for repairs & strengthening of historic members – rivet removal & bolt installation; 4) Repair details developed during construction for ‘secondary’ members - damaged floor beams, stringers, gusset plates & bracing; 5) Repair details developed during construction for ‘primary’ members – truss diagonals & tension chords; & 6) Appropriate contingency allowances during construction & cooperation with the Contractor. This paper will provide a description of the project along with the solutions and responses to challenges encountered during construction, culminating in several lessons learned that can be applied to future projects.