In Load and Resistance Factor Design (LRFD), what is the initial step in the strength design process?

The initial step in the strength design process using Load and Resistance Factor Design (LRFD) is to determine the design load. This step is crucial as it establishes the basis for the entire design process, which involves evaluating how the structure will respond to various imposed loads throughout its service life.

In LRFD, design loads are calculated by considering various load types, such as dead loads, live loads, wind loads, seismic loads, and other applicable forces. Each type of load is factored according to its level of uncertainty and significance, allowing engineers to develop a comprehensive understanding of the maximum load scenarios that the structure may face.

After determining the design load, the subsequent steps involve analyzing the structure's response to these loads and comparing it against the reduced nominal strength of the materials being used, which is essential for ensuring that the structure can safely withstand its intended loads under various conditions. This sequential approach underscores the importance of accurately assessing loads as the foundation for establishing the reliability and safety of the design.