Bridge Engineering MCQ with answer and solution

Concept

Cable stayed bridges are economical for long spans, generally above about 100 m (roughly 100 to 1000 m).

Step-by-step solution

1. Cable stayed bridges use inclined cables fixed to pylons. 2. They are best for medium to long spans. 3. Short spans (up to 50 m) are cheaper with slab, girder or box girder bridges. 4. Among the options, only 'Above 100 m' fits. 5. Answer: D.

Explanation

Cable stayed bridges are used for long spans, usually above 100 m. For short spans, simpler bridge types are cheaper and easier to build.

Why the other options are wrong

A, B, C: These spans are small and are better handled by slab or girder bridges. Cable stays would be uneconomical.

Shortcut

Cable stayed means long span, above 100 m.

Common mistake

Mixing up cable stayed (about 100 to 1000 m) with suspension bridges (very long spans, often above 500 m).