Performance‐Based Probabilistic Seismic Hazard Analysis Incorporating Fault‐Specific Minimum Magnitude

ABSTRACT

Accurate estimation of seismic hazard is a fundamental requirement for achieving resilient and cost‐efficient structural design. Traditional Probabilistic Seismic Hazard Analysis (PSHA) typically employs a constant minimum earthquake magnitude m _min for all seismic sources. This simplification can result in either overestimation or underestimation of hazard levels, as it disregards variations in structural performance and source‐specific fault characteristics. This paper proposes a Performance‐based Probabilistic Seismic Hazard Analysis (PbPSHA) framework in which m _min is determined individually for each fault by incorporating fault‐to‐site distance, structural performance objectives, and building vulnerability. The proposed methodology incorporates risk components into the hazard assessment and applies an iterative process that couples hazard estimation with damage evaluation until convergence of the m _min is attained. Two numerical examples are presented to demonstrate the methodology. The first example evaluates an existing reinforced‐concrete building, determining fault‐specific m _min values based on nonlinear dynamic analysis and fragility‐based performance criteria. These values are subsequently incorporated into the PbPSHA framework and compared with the results of conventional PSHA employing a constant m _min assumption, revealing notable differences under design‐level hazard conditions. The second example applies the iterative PbPSHA approach to a new building design, illustrating its capability to integrate performance objectives into hazard definition during early design stages. Results confirm that PbPSHA provides a more physically meaningful and risk‐consistent hazard representation, while also indicating that a simplified approach using the average fault‐specific m _min value can serve as a computationally efficient alternative when detailed iteration is not feasible. The proposed methodology enhances the rationality and defensibility of seismic hazard analysis by establishing fault‐specific and performance‐consistent magnitude thresholds. This approach enhances the reliability of seismic design and risk management, especially for structures with strict performance requirements or those located in regions characterized by diverse seismic sources.