Which design method introduces load factors and a strength reduction factor to address ASD drawbacks?

• A. Load Factor Design
• B. Level II Earthquake Motions
• C. Load and Resistance Factor Design
• D. Level I Earthquake Motions

Answer: (A)

Load and Resistance Factor Design introduces specific load factors for different loads and a resistance (strength) reduction factor to account for uncertainties in materials, workmanship, and用途. This approach builds in reliability by ensuring that, when the worst combination of loads is applied and the member strengths are reduced by the φ factor, the structure consistently meets a specified safety target. It addresses ASD drawbacks by making the margin of safety more uniform across different loading scenarios, rather than relying on fixed allowable stresses that can vary in level from one material and condition to another. The other options refer to motion levels or a different naming convention, but they do not describe the design method that uses explicit load factors together with a strength reduction factor.