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A major cause of local to total damages is related to structural pounding in a large number of past earthquakes. In general, these collisions take place as a result of differences in the dynamic characteristics of the colliding structures. To acquire a better perception of the behavior of structures, in this paper, three structures featuring different heights are modeled in series and with various configurations next to each other in OpenSees. To determine the collision effects of the structures, three different configurations of 4-, 8- and 12-story adjacent reinforced concrete special moment resisting frames were considered. Then, by conducting an incremental dynamic analysis, their structural seismic limit state capacities were assessed via 20 near-field record subsets recommended by FEMA-P695. At last, for the above adjacent buildings with various separation distances and configurations, the fragility curves were determined, and the probability of exceedance from the primary Hazus-MH failure criteria was estimated. In addition, the results were compared with those obtained when this phenomenon did not take place for buildings to have a better perception of the pounding phenomenon. The results of the analyses show that arranging adjacent structures in series greatly affects the collapse capacities of the colliding structures. In addition, in the case when the shorter structure is placed in the middle of two taller structures, it results in the most critical situation among all configurations, and in this case, a higher reduction is observed in the structural performance levels. [ABSTRACT FROM AUTHOR]

Vibration-based structural health monitoring (VSHM) relying on model updating methods has been developed greatly and nowadays, not only serves as a major subset of SHM, but also shapes a special class of optimization problems. The historical course of evolution of this field via different research groups and with different goals and objectives, has resulted in the emergence of multiple objective functions, each appropriate only for certain damage scenarios and incapable of reasonably addressing others. The natural frequency residual (NFR) is an objective function sensitive to the damage intensity, which in the meantime, fails to predict the damage location in the symmetric structures. The total modal assurance criterion (TMAC) is another objective function which is sensitive to the damage position, but fails to estimate of the damage severity in the uniformly damaged structures. The present work successfully provides an innovative solution to unify both aforementioned objectives in a holistic objective function (HOF), through a particular combination of NFR and TMAC. Additionally, the competency of the above HOF for solving the VSHM problems has been investigated and demonstrated using a symbiotic organism search (SOS) optimization algorithm. The robustness and efficiency of the proposed VSHM method are verified through assessment of two un-damped benchmark structures. The obtained results indicate that in all damage scenarios, the HOF predicts with a high precision the damage location and succeeds in the high accuracy estimation of the damage extent. Consequently, the combination of the proposed HOF criterion and the SOS optimization algorithm is recommended as a reliable technique for VSHM. [ABSTRACT FROM AUTHOR]