Fundamental Principles for the Design of Earthquake-Resistant Structures

This chapter provides a concise qualitative overview of the philosophy for earthquake resistant design of ordinary structures adopted by relevant international codes of practice, including Eurocode 8. The aim is to facilitate practicing engineers with the interpretation of the code-prescribed design objectives and requirements for the seismic design of ordinary reinforced concrete (r/c) building structures which allow for structural damage to occur for a nominal design seismic action specified in a probabilistic manner. In this regard, the structural properties of stiffness, strength, and ductility are introduced along with the standard capacity design rules and requirements. Further, the role of these structural properties in the seismic design of r/c building structures following a force-based approach in conjunction with equivalent linear analysis methods is explained. Emphasis is placed on delineating the concept of the behaviour factor, or force reduction factor, which regulates the intensity of the seismic design loads and ductility demands. Moreover, the development and current trends in the emerging performance-based design approach for earthquake resistance are briefly reviewed. Lastly, practical recommendations to achieve higher-than-the-minimum-required by current codes of practice structural performance within the force-based design approach are provided.