Time-to-Functionality Fragilities for Performance Assessment of Buildings

Jace Furley,Eric Mcdonnell,J Daniel Dolan,Hamed Hasani,Sarah Wichman,John W Van De Lindt,Keri Ryan,Shiling Pei,Jeffrey W Berman,Reid B Zimmerman

doi:10.1061/(asce)st.1943-541x.0003195

Abstract

This paper presents a new stochastic methodology for evaluating and quantifying the downtime of a structure in terms of a family of fragilities that represent the probability of exceeding prescribed times to return to functionality. This methodology integrates several existing concepts, namely, Federal Emergency Management Agency P-58 and Resilience-based Earthquake Design Initiative (REDi), to build a family of system (building) level fragility curves corresponding to the time needed to achieve different recovery levels (reoccupancy, functional recovery, and full recovery). This approach enables one to propagate uncertainty throughout the procedure so that variations in the delay time and repair schedules are accounted for in the resulting fragilities. As an illustrative example of this approach, the methodology is applied to assess the downtime of a two-story mass timber building that was originally tested at the [email protected] outdoor shake table in 2017. One unique aspect of this analysis is that it incorporates a relatively new material, cross-laminated timber (CLT), in a resilient posttension rocking wall design application. Nonstructural components representing a typical office building were selected and incorporated into the procedure for the two-story CLT rocking wall building. Time-to-functionality fragility curves are then developed for the two-story building, and potential design and resilience-focused applications are discussed.

Highlights

IntroductionEngineering attention, primarily in the form of performance-based seismic design over the last several decades
The ability to mitigate seismic risk with the application of a new design philosophy has garnered significant academic and professional engineering attention, primarily in the form of performance-based seismic design over the last several decades
The methodology laid out in this study allows for the development of TTF fragility curves that incorporate both structural and nonstructural components, as well as a variety of uncertainties

Summary

Introduction

Engineering attention, primarily in the form of performance-based seismic design over the last several decades. While life-safety remains the fundamental objective of any seismic design philosophy, additional impacts of a seismic event such as financial losses (both direct and indirect losses), societal disruptions, and adverse effects (e.g., population migration and community degradation) are being considered more directly through modeling This translates into a more comprehensive consideration of the resilience of a building system and the broader interconnected community network by including the ability to recover after an earthquake. Terzic et al (2016) developed a repair model designed to integrate with PACT utilizing the critical path method (CPM) to estimate the repair time This model was designed to be an applicable repair model in a larger effort to determine the resiliency index of a building as defined in Cimellaro et al (2010). The authors’ involvement in the testing of this specimen enabled better integration of the results with the new methodology in this study

Methodology

Findings

Conclusions