In which bridge does the span consist of a deck slab, a series of walls and a bottom slab, creating weight for longer spans?

In which bridge does the span consist of a deck slab, a series of walls and a bottom slab, creating weight for longer spans?

• A. Box Girder Bridge
• B. Beam and Slab Bridge
• C. Suspension Bridge
• D. Arch Bridge

Answer: (A)

A bridge with a deck slab, a series of walls, and a bottom slab forms a closed box-shaped cross-section. This box girder arrangement creates a rigid, hollow section that resists torsion and distributes bending stresses more efficiently along the length, which is why it’s well suited to longer spans. The weight and stiffness of the closed box help keep deflections in check and provide structural stability as spans increase. In contrast, a beam-and-slab bridge sits on top of separate beams, without a boxed interior; a suspension bridge relies on cables to carry loads, and an arch bridge uses an arch action to transfer loads. The description given—deck slab plus walls plus bottom slab forming a weighty, closed section—fits the box girder design best.

A bridge with a deck slab, a series of walls, and a bottom slab forms a closed box-shaped cross-section. This box girder arrangement creates a rigid, hollow section that resists torsion and distributes bending stresses more efficiently along the length, which is why it’s well suited to longer spans. The weight and stiffness of the closed box help keep deflections in check and provide structural stability as spans increase.

In contrast, a beam-and-slab bridge sits on top of separate beams, without a boxed interior; a suspension bridge relies on cables to carry loads, and an arch bridge uses an arch action to transfer loads. The description given—deck slab plus walls plus bottom slab forming a weighty, closed section—fits the box girder design best.