What are factored loads in structural design?

Factored loads in structural design refer to the principle of applying safety factors to service loads to account for uncertainties in load estimates, material properties, and the overall performance of the structure under various conditions. They are obtained by multiplying the service loads—those loads anticipated during normal use—by specific amplifying factors as outlined in design codes and standards.

This approach ensures that structures are designed with an adequate safety margin, accounting for possible overload scenarios or unexpected conditions that may arise in service. The factors used in this multiplication are derived from statistical analyses and are aimed at ensuring reliability and safety throughout the life of the structure.

In contrast, the other options do not accurately reflect the concept of factored loads. The idea of simply decreasing loads by safety factors does not align with the intent of ensuring safety through amplification. Similarly, limiting loads to conservative estimates fails to address the probabilistic nature of load occurrence and does not provide a comprehensive understanding of structural design requirements. Lastly, focusing only on loads experienced under specific design conditions neglects the broader range of loads that structures may encounter over their lifespan, making it vital to consider both service and extreme load scenarios.