What is the purpose of a structural redundancy check and how is it quantified?

• A. To ensure alternative load paths exist beyond the primary; quantified by redundancy index or number of independent load paths.
• B. To optimize material usage.
• C. To minimize construction cost.
• D. To evaluate serviceability performance.

Answer: (A)

The idea being tested is having backup load paths so a structure can still carry forces if the primary path is compromised. A redundancy check asks whether there are alternative routes for loads to reach the supports, beyond the main path, so the structure can redistribute stresses and avoid collapse. It’s quantified by counting independent load paths or using a redundancy index—the more independent paths present, the higher the redundancy and the more robust the system. For example, adding another brace or conduit path creates an extra independent route for forces, increasing reliability if part of the primary path fails. The other options focus on efficiency, cost, or serviceability, which aren’t the measure of structural redundancy.