An arch-type bridge constructed with steel beams encased in concrete is called what?

• A. Cantilever
• B. Jack Arch
• C. Through Arch
• D. Suspension

Answer: (B)

This type of arch bridge relies on an arch action created by encasing steel members in concrete. Steel beams form the structural ribs, and the surrounding concrete turns those ribs into a single arch that carries the load in compression, with the deck typically supported on top or integrated into the arch section. The result is a shallow, arch-like span that behaves like a concrete-encased steel arch.

This fits the description because the other options describe different bridge concepts: a cantilever bridge uses projecting arms that extend from piers and meet in the middle without a true arch formed by encased members; a through-arch bridge has the arch rising above the deck and traffic passing between the legs of the arch; a suspension bridge carries the deck on cables hung from towers.