In the move toward design practices that facilitate recovery, there are ongoing efforts to reevaluate structural seismic design parameters such as design drift limits and response modification coefficients. To support the development of the 2026 NEHRP functional recovery design provisions, we propose design modifications that limit the occurrence of safety‐critical structural damage, i.e., damage that must be repaired for occupants to be able to safely return to a building. First, we outline structural design checks to be performed at a new risk‐targeted Functional Recovery Earthquake, FRE R , that follow a similar structure to current ASCE 7 life‐safety requirements. We then apply these recommendations and evaluate the probability of safety‐critical structural damage in a wide range of conventional lateral force‐resisting systems, including reinforced concrete shear walls, buckling‐restrained braced frames, and steel and reinforced concrete moment frames. For each system, we evaluate buildings designed with combinations of drift limits ranging from 0.5% to 2.0% and response modification coefficients ranging from 1.0 to the current ASCE 7 values. This design space is developed for each lateral force‐resisting system type over a range of building heights (i.e., 3–24‐stories) to identify potential combinations of design drift limits and response modification coefficients that meet a target safety‐critical structural damage probability of 10% at the FRE R . The impact of damage to gravity systems, when paired with each lateral system, is also considered. The results include new functional recovery allowable drift limits, Δ afr , and response modification coefficients, R fr, for each system considered. Ultimately, this study aims to establish performance objectives and preliminary recommendations for structural design requirements that limit safety‐critical structural damage for recovery‐based design.
Blowes et al. (Sun,) studied this question.