A set of new cable stayed bridges are set to replace the current Kosciuszko Bridge that spans over Newport Creek in New York. The bridge is part of Interstate 278 and it connects Brooklyn and Queens. As part of the early design for the new Kosciuszko Bridge, Hinman was tasked by HNTB to assess and mitigate the effect of a vehicle fire threat on the new bridge structure. In addition, we provided peer review services for the explosion mitigation design performed by HNTB.
For the fire threat, Hinman Consulting Engineers used our in-house program FLaME (Fire Loading and Mitigation Evaluator) to model the bridge geometry and the vehicle fire threat. Hinman understands that cable stayed bridges are required to maintain stability with the loss of a single cable. Knowing the typical safety factors that cables are designed for and the basic geometry of the bridge, Hinman ran analyses to provide the minimum height of cable protection needed to keep the bridge protected. This minimum height is the baseline for the Phase 2 collaboration with the structural design team. By collaborating with the structural design team, Hinman will redefine the design criteria for fire protection, and provide a more optimized fire protection layout for the bridge.
Hinman used the in-house program FLaME (Fire Loading and Mitigation Evaluator) to model the bridge geometry and the vehicle fire.
Hinman also used FLaME to run a through-thickness analysis of the concrete towers. This analysis helped provide the design team with the expected critical heat penetration into the towers and a mitigation strategy to limit concrete spalling. Hinman was able to provide direction to the structural design team and increase resiliency of the tower in the event of a large vehicle fire threat on the roadway.
Known for our work for design mitigation to resist explosion effects, HNTB entrusted us to review and comment on their design. Our comments were submitted as part of our deliverables.