Civil Engineering Professional Engineer Practice Exam

When are beam bridges most commonly utilized?

1. For highways over long distances

2. When one road crosses another

3. In locations with unstable soil

4. For pedestrian walkways

The correct answer is: When one road crosses another

Beam bridges are most commonly utilized for situations where one road crosses another, such as in urban environments with intersections or highway overpasses. This is because beam bridges are simple in design and can effectively span short to moderate distances, making them well-suited for situations where elevation changes are needed for one roadway to cross over another without obstructing traffic flow. These bridges consist of horizontal beams supported by vertical piers or walls, allowing them to transfer loads efficiently. The straightforward construction and material requirements of beam bridges make them a practical choice for various crossing scenarios, particularly where quick and cost-effective solutions are necessary. In contrast, other options like using beam bridges for highways over long distances or in locations with unstable soil are less common. Longer spans require more complex bridge designs, such as arch or cable-stayed bridges, which can handle greater loads and provide stability under varying conditions. Additionally, unstable soil conditions often necessitate specialized foundation designs rather than standard beam bridge solutions. While pedestrian walkways can indeed utilize beam bridges, they are not the primary application for them, as other types of structures may be more appropriate for pedestrian crossings or dedicated walkways.