Summary This paper proposes a novel fully probabilistic framework for the performance‐based seismic design of structures and uses tuned inerter dampers (TID) installed in civil engineering structures subjected to seismic loads to illustrate its applicability. The framework proposed is based on stochastic reduced‐order models, which makes it computationally efficient and can be used for the design of TIDs installed in any complex nonlinear structures subjected to general nonstationary, non‐Gaussian stochastic processes. In this study, the TID is installed in a multi‐degree‐of‐freedom nonlinear structure that is subjected to synthetic seismic records. Numerical results show that the framework proposed is able to provide rigorous and robust values for the parameters of the TID. The design parameters obtained using the stochastic framework proposed are compared with benchmark deterministic approaches, tested also for a large data set of ground‐motion real records. It is shown that the stochastic approach provides insightful designs of the TID that are consistent with the site seismicity and the frequency content of the stochastic excitation.

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This study presents a calibration of CAT-in-a-Box and intensity-based index trigger mechanisms for parametric tsunami catastrophe bonds. Trigger conditions for the former are based on fundamental event characteristics, such as earthquake location and magnitude, whereas those for the latter utilize tsunami wave height measurements at a series of observation stations. These solutions are illustrated for a building portfolio in Iwanuma City in Miyagi Prefecture, Japan, by considering a new seafloor observation network S-net off the Tohoku-Hokkaido coast of Japan. Performances of the two types of parametric solutions are quantitatively evaluated and compared with each other to discuss their advantages and disadvantages.

The seismic fragility of a system is the probability that the system enters a damage state under seismic ground motions with specified characteristics. Plots of the seismic fragilities with respect to scalar ground motion intensity measures are called fragility curves. Recent studies show that fragility curves may not be satisfactory measures for structural seismic performance, since scalar intensity measures cannot comprehensively characterize site seismicity. The limitations of traditional seismic intensity measures, e.g., peak ground acceleration or pseudo-spectral acceleration, are shown and discussed in detail. A bivariate vector with coordinates moment magnitude m and source-to-site distance r is proposed as an alternative seismic intensity measure. Implicitly, fragility surfaces in the (m, r)-space could be used as graphical representations of seismic fragility. Unlike fragility curves, which are functions of scalar intensity measures, fragility surfaces are characterized by two earthquake-hazard parameters, (m, r). The calculation of fragility surfaces may be computationally expensive for complex systems. Thus, as solutions to this issue, a bi-variate log-normal parametric model and an efficient calculation method, based on stochastic-reduced-order models, for fragility surfaces are proposed.

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