What is the primary purpose of defining load factors in structural design?

The primary purpose of defining load factors in structural design is to account for uncertainty and ensure safety. Load factors are multipliers applied to the nominal loads that a structure may experience, such as live loads, dead loads, and environmental loads (like wind or seismic forces). These factors help to take into consideration the variability and unpredictability of these loads, as well as uncertainties in material properties and construction practices.

By applying load factors, engineers can design structures that not only meet the expected loads but also provide a margin of safety for unexpected situations. This approach is a critical part of the design process, as it promotes reliability and helps to mitigate potential risks associated with structural failures. The consideration of safety helps protect human lives and property, which is the primary concern in structural engineering.

In contrast, while reducing costs, simplifying calculations, and avoiding loading analysis can be relevant to certain engineering considerations, they do not capture the essential purpose of load factors, which is fundamentally about incorporating safety and managing uncertainty in design.