Evaluation of the Collapse Capacity Ratio of the Near Fault to the Far Fault and Its Effect on Collapse Risk in Terms of Pulse Period and Formability

The seismic collapse capacity of a structure is a critical factor in earthquake risk assessment within engineeringpractices. Conventionally, evaluating this capacity involves intricate and time-consuming incremental dynamicanalyses. However, recent progress has brought forth alternative, streamlined methodologies grounded in the use ofstructural behavior curves. This study employs the application of these innovative approaches to comprehensivelyassess the seismic collapse capacity of structures. Embracing advancements, it strives to enhance the efficiency andprecision of seismic risk assessments in engineering practices.In addition to the efficiency of assessment methodologies, it is imperative that the calculation of seismic collapsecapacity aligns with the specific demands of the construction site. This ensures that the seismic risk falls within theestablished allowable limits. This consideration becomes particularly critical for construction sites located in closeproximity to fault zones. In such areas, the presence of directivity pulses heightened attention to seismic collapsecapacity. Recognizing that structural ductility and the pulse period ratio in the near-fault are primary factorsinfluencing seismic collapse capacity, which is demanded in site, this study delves into a detailed numericalinvestigation of these critical elements. Subsequently, the seismic collapse capacity demanded in the near-fault ismeticulously estimated based on these considerations.The extensive investigations undertaken in this study yield insightful revelations. It is evident that heightenedstructural ductility correlates with an augmentation of seismic collapse capacity, both in the near-fault and far-faultscenarios. Conversely, a reduction in seismic collapse capacity in the near-fault is discerned as the pulse period ratioincreases concerning the fundamental period of the structure. To conduct a comprehensive evaluation, the ratio ofseismic collapse capacity in the near-fault to that in the far-fault is calculated, taking into account both ductility andpulse period ratio. This derived parameter, denoted as γ, is then employed to estimate the seismic collapse capacitydemanded in the near-fault. This analysis contributes valuable insights to the understanding of seismic behavior inboth near-fault and far-fault regions.For the assessment of seismic collapse capacity demand at construction sites, the study recommends theutilization of a lower bound of the ratio of near-fault to far-fault seismic collapse capacity. This lower bound,associated with lower ductility and a higher pulse period ratio, is not just conservative but also robust. Importantly,this cautious approach ensures that an increase in this parameter does not significantly escalate the demand at theconstruction site. Such a calculated and conservative estimation of seismic collapse capacity demanded contributesto a more resilient seismic risk assessment for structures situated in near-fault zones.In conclusion, the results indicate that for the assessment of seismic collapse capacity that is demanded atconstruction sites in near-fault zones, utilizing a lower bound of the ratio of near-fault to far-fault seismic collapsecapacity, associated with lower ductility and higher pulse period ratio, is sufficiently conservative. Moreover, anincrease in this parameter does not significantly escalate the demand at the construction site.This approach ensures a cautious estimation of seismic collapse capacity demand, contributing to a more robustseismic risk assessment for structures in near-fault zones.