To accurately predict the seismic demands of structural systems, a proper set of ground motions representing the seismic hazard of a given site is needed. In general, such a set includes a large ...number of ground motions, and thus may result in high computational cost. To address this computational challenge without compromising the accuracy of structural fragility, this paper proposes a clustering‐based algorithm that can select a representative subset of ground motions adaptively from a given set of ground motions. First, critical features of ground motions that significantly affect seismic demands of the structural system are identified by Lasso regression of seismic responses of various single degree of freedom systems on existing intensity measures of ground motions. Second, ground motions are selected adaptively based on the hierarchical clustering of the critical features until the fragility curve converges. Applications to a reinforced concrete building and steel moment‐resisting frames demonstrate the improved efficiency and wide applicability of the proposed method. The results of the numerical examples confirm the robust performance of the proposed algorithm against various ground motions, structural types, and definitions of the limit‐states. The proposed algorithm enables us to obtain structural fragilities using a significantly reduced number of ground motions while keeping consistency with the available ground motion set.
•The seismic behaviour of infilled R/C frames within the context of Performance Based Earthquake Engineering was examined.•A number of R/C buildings with different masonry infills' distributions were ...subjected to Incremental Dynamic Analysis.•Different damage measures were used to assess the seismic behaviour.•The parameters determining the influence of the infill effect on the global seismic response were determined.
The present paper constitutes an analytical study on the seismic behaviour of infilled reinforced concrete frames within the context of the Performance Based Earthquake Engineering. For this aim, a large number of planar reinforced concrete frames with different structural systems, storeys number, masonry infills’ distributions and mechanical properties are studied. Non-linear dynamic analysis is used to simulate the seismic behaviour of the frames against a suite of appropriately chosen earthquake records, scaled to ten different seismic intensity level. The quantitative assessment of the seismic behaviour of each frame is accomplished by means of several different damage measures. Subsequently, these results are meticulously interpreted to assess the overall infill effect on the seismic behaviour of the frames. The results of the research study demonstrate that the infill effect depends greatly on specific characteristics of the main bearing structure and the infill walls. Moreover, the relation between these characteristics and the seismic performance of the infilled frames is found to be consistent across all the frames under investigation and quantifiable. Aggregated results show that certain types of low-rise frames are prone to the adverse infill effect, even with infills of regular distribution, while other frame types are able to benefit from the presence of masonry infills.
Due to the great human and social impacts of natural hazards, the concept of community resilience has gained unprecedented attention across multiple disciplines in the last decade. While most studies ...focused on the assessment and quantification of community resilience, there is a lack of research on how to incorporate the probabilistic seismic performance, which is obtained from performance-based earthquake engineering (PBEE), of individual buildings into the assessment. This manuscript presents a framework to bridge the gap between seismic performance of buildings and community resilience. In addition, a novel long-term resilience indicator integrating the probability of earthquakes with different magnitudes is proposed. The framework can be used to assess if the desired community resilience goals can be achieved by evaluating the seismic performance of buildings and other infrastructure systems. To explicitly account for the interdependence of different infrastructure systems during the restoration process, a network-based recovery model is established. The framework is illustratively applied to a community consisting of buildings, power distribution system, and transportation system by performing a large number of post-earthquake recovery simulations. The simulation results demonstrate that the framework is effective to link the proposed long-term resilience indicator to the seismic performance of individual buildings and it highlights the importance of considering the interdependence between infrastructure systems in community resilience assessment.
•Long-term seismic resilience indicator integrating earthquake probability.•Framework to link resilience goals to seismic performance of individual buildings.•Network-based post-earthquake recovery modeling method.•Recovery of buildings considering transportation and power distribution systems.
•Surrogate model is used to assist performance-based earthquake engineering.•Vector intensity measure is coupled with surrogate model to improve the PBEE.•Vine copula is used to capture the complex ...dependence within PBEE.•An updated PBEE framework is proposed by interconnecting several techniques.•The effect of dependence modeling on higher-order moments of performance is clarified.
Performance-based earthquake engineering (PBEE) is an advanced philosophy for the design, assessment, and decision-making of structures under seismic hazards. Improving the accuracy and efficiency of PBEE is of great importance. In traditional cloud analysis, a linear regression is performed in the logarithmic space of seismic intensity measure (IM) and demand. The obtained relationship is used to predict the seismic demand. Then, some advanced models for seismic demand prediction were developed to improve the accuracy. There exists dependence within PBEE, whereas multivariate normality of logarithmic values is widely assumed for modeling the dependence in previous studies. This paper proposes a hybrid and novel framework to improve the seismic performance assessment. The proposed framework can improve confidence while capturing more realistic dependence. The vector IM and surrogate models are coupled to predict the seismic demand. The vine copula can characterize complex nonlinear dependence structures, and it is adopted to model the dependence of demands and IMs. Then, seismic performance can be assessed. The proposed framework is illustrated on bridges under seismic hazards. For the investigated cases, the proposed framework can improve confidence significantly and better capture complex dependence. Additionally, the effect of dependence modeling on higher-order moments of seismic performance is investigated. Within the investigated cases, the large difference of higher-order moments of seismic performance is observed by using conventional assumption and vine copula. The generality and flexibility of vine copula-based approach highlight the necessity of implementing the proposed framework.
Summary
A series of scalar and vector intensity measures is examined to determine their suitability within the seismic risk assessment of liquid storage tanks. Using a surrogate modelling approach on ...a squat tank that is examined under both anchored and unanchored support conditions, incremental dynamic analysis is adopted to generate the distributions of response parameters conditioned on each of the candidate intensity measures. Efficiency and sufficiency metrics are used in order to perform the intensity measure evaluation for individual failure modes, while a comparison in terms of mean annual frequency of exceedance is performed with respect to a damage state that is mutually governed by the impulsive and convective modes of the tank. The results reveal combinations of spectral acceleration ordinates as adequate predictors, among which the average spectral acceleration is singled out as the optimal solution. The sole exception is found for the sloshing‐controlled modes of failure, where mainly the convective period spectral acceleration is deemed adequate to represent the associated response due to their underlying linear relationship. A computationally efficient method in terms of site hazard analysis is finally proposed to serve in place of the vector‐valued intensity measures, providing a good match for the unanchored tank considered and a more conservative one for the corresponding anchored system.
The paper investigates the potential of adopting the spectral acceleration S
a
(T) as an efficient measure for the estimation of the seismic performance of bare and infilled R/C buildings within the ...context of Performance-Based Earthquake Engineering. A large number of planar R/C buildings with different masonry infills' distributions are analyzed using nonlinear time-history analyses. The correlation between several damage measures and the S
a
(T) for a wide range of periods is investigated. The results point out the conditions under which the S
a
(T) can be used as an efficient parameter that describes adequately the damage response of bare and infilled R/C frames.
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