Speaking

The I.B. Perrine Bridge is a 1500-foot-long steel arch structure carrying US 93 over the Snake River Canyon near Twin Falls, Idaho. This landmark structure is among the highest bridges in the United States, with the top of the deck located 486 feet above the Snake River. The Idaho Transportation Department (ITD) retained B&N to develop a comprehensive, long-range Asset Management Plan (AMP) for the bridge. While compiling the AMP, B&N identified deficiencies that warranted immediate attention to extend the service life of the bridge.

Repair plans included replacement of corroded bolts in the arch end posts, installation of protective coatings in corrosion-prone areas, repairs to the inspection access system, repairs to the concrete substructures and repairs to the sidewalk joints. Construction access for the repairs was difficult due to the nature of the work and the position of the bridge. Bolt replacements, in the end posts, required workers to enter confined chambers through small openings to reach the repair location. In addition, the extreme height of the structure made accessing the below-deck repairs a challenge.

ITD's Bruce Christensen will co-present as speakers discuss the details of repairs and deficiencies.