Mathews Bridge Emergency Repair

The Work

Work began immediately on the temporary support, with crews operating day and night on this fast-track project. We used an air winch in place of a crane due to equipment and weight restrictions on the bridge. Once the strongback, Dywidag bars, saddles, and fortresses were systematically put in place, we performed bar stressing as the system was incrementally post-tensioned, with pauses to check the geometry of the bridge.

After we raised preassembled scaffolding into place and secured from below the bridge, we began permanent repairs. We removed the sheared bottom chord in three-foot increments via the air winch. We lowered members, a guest plate, and a lateral brace onto our barge. Sections of existing steel were repaired through the use of heat-straightening before installation of new steel. Ingenuity led us to remove existing fill plates — an extremely challenging task due to proximity of the impact — and then split the replacement chords into sections for easier installation. A new sub beam, bolting, and a new cheese plate and outside gusset plate, which required installation without removal of the old one, secured the substantial repair work.