Accounting for near-source effects in the displacement coefficient method for seismic structural assessment

Non-linear static procedures are well-established analytical tools for performance-based seismic design and assessment. On the other hand, near-source (NS) ground motions are emerging as relevant to structural engineering because they may be characterized by seismic demand larger and systematically different than that typically induced by so-called ordinary records. This is the result of phenomena such as rupture forward directivity (FD), which may lead to the appearance of distinct velocity pulses in the ground motion velocity time-history. Lately, effort was put towards the framework necessary for taking FD into ac-count in probabilistic seismic hazard analysis (PSHA). The objective of the present study is to discuss the extension of non-linear static procedures, such as the displacement coefficient method (DCM), with respect to the inelastic demand associated with FD. In this context, the DCM is implemented to estimate NS seismic demand by making use of the results of NS-PSHA, developed for single-fault-case scenarios. A predictive model for NS-FD inelastic displace-ment ratios, previously developed by the authors, is employed. An illustrative application of the DCM, with explicit inclusion of NS-pulse-like effects, is given for a plane R/C frame de-signed under modern code provisions.