What are values of Fa and Fv found in CBC Chapter 16 tables used for?

In the context of the California Building Code (CBC) Chapter 16, the values of Fa (Site Amplification Factor) and Fv (Site Amplification Factor for Vertical Motion) are crucial for finding site coefficients, which are essential in seismic design. These coefficients are used to adjust the seismic forces calculated for buildings based on the characteristics of the site, including soil type and conditions, which significantly influence the seismic response.

Utilizing Fa and Fv allows engineers to ensure that the design and construction of buildings take into account site-specific conditions that might amplify or diminish seismic forces, enhancing safety and structural integrity. They provide a means to quantify how the local geology may affect the ground shaking that buildings experience during an earthquake. By selecting the correct values for Fa and Fv based on the soil's properties found in the tables, engineers can develop better-informed, code-compliant designs that accurately account for potential seismic hazards.

This understanding of site coefficients is critical in seismic analysis, leading to appropriate engineering responses that help mitigate risks associated with earthquakes.