Photo courtesy JGM

Because some of the girders could not be jacked up from the floor using shoring towers, the team custom-engineered an innovative roof-based jacking system that would lift the girders from outside. Placing a cribbing stand atop the column locations, the team spanned the girder with two jacking beams. Cable was run through the roof and coupled to the bottom of the girder. Using a hydraulic jack on the beams, the team was able to “unload” the girders before the reinforcing steel was welded on. Strain gauges were utilized to remotely monitor the roof structure, ensuring that the loads introduced from the scaffolding, reinforcement operations and snow loads during the winter months did not exceed the structure’s capacity.

During the project, the team conducted more than 530 formal safety inspections, resulting in zero lost-time incidents and no disruption to the sensitive operations taking place beneath the work area. Because the scaffold deck blocked the sprinkler system, fire watch personnel were positioned both above and below the deck throughout the project. To safeguard air quality during extensive welding activities, the team deployed real-time environmental monitoring coupled with the temporary installation of high-capacity exhaust fans to manage smoke from welding operations. Safety netting protected workers, equipment and inventory prior to moving the scaffolding.