NHI Bridge Safety Inspection Practice Exam (Midterm) for In-Service Bridges

The grid deck is often found on moveable and rehabilitated bridges due to its unique structural characteristics that lend themselves well to the dynamic and operational requirements of such structures. Grid decks consist of a series of interconnected steel plates, which create a lightweight yet strong surface suitable for bridging gaps and accommodating movement.

In the context of moveable bridges, the grid deck allows for easier access to mechanical components used in the operation of the bridge, facilitating maintenance and repairs without the need for extensive and cumbersome modifications. This modular design also helps in reducing the overall weight of the deck, which is crucial for ensuring that the mechanisms of moveable bridges can operate effectively.

Furthermore, rehabilitated bridges often utilize grid decks because they can be retrofitted into existing structures more easily compared to other deck types. The open grid pattern can provide a level of flexibility and adaptability, which is essential when working with older bridge designs that may have unique spatial constraints.

While other deck types, like orthotropic or composite decks, have their own advantages, they typically do not offer the same level of accessibility and ease of integration for moveable environments and retrofitting scenarios as the grid deck does.