Finite element modeling and operational modal analysis of a historical masonry mosque

Finite Element Modeling (FEM) and Operational Modal Analysis (OMA) is herein presented for the historical masonry Kütahya Kurşunlu Mosque within the framework of its seismic performance assessment. The historical structure is located in Turkey which has a high-level seismic activity. A FEM strategy was adopted to construct a numerical model of the structure considering a simplified three-dimensional geometry and a macro-modeling approach for the masonry. A representative numerical model of the existing structure was calibrated and improved according to the OMA results obtained from ambient vibration measurements, performed in-situ. The ambient vibration measurements were operated by using two triaxial accelerometers, that one of the accelerometers was regulated as a reference station whereas the other accelerometer was relocated to seven different points on the top of the walls. Identification of the experimental modal parameters was achieved by performing two different signal processing methodologies, namely the Enhanced Frequency Domain Decomposition (EFDD) and the Stochastic Subspace Identification - Unweighted Principal Components (SSI-UPC). Results obtained from both methods were compared in terms of the Modal Assurance Criterion (MAC) which considers the mode shapes derived in a specific range of frequency. The SSI-UPC method was employed in achieving the experimental modal response of the structure and the results were compared with the eigenvalue analysis results of the preliminary numerical model. A calibration process was carried out in terms of minimizing the difference between the experimental and numerical modal response by a trial and error approach and an average error of 4.9% was calculated for the modal frequencies of the first four global modes of vibration

In situ testing and modeling of cultural heritage buildings in Peru

This paper provides the results of in situ testing and modelling of four case studies in Peru and is part of the ongoing Seismic Retrofitting Project, under the auspices of the Getty Conservation Institute (GCI): CasaArones (Cusco), Hotel Comércio (Lima), Ica Cathedral (Ica) and KuñoTambo (Acomayo).These are mostly earthen buildings made with adobe, with the presence of large amounts of timber and, in some cases, brick masonry and rubble stone masonry (mostly for the base course in contact with the ground). In situ testing consist of an extensive sonic testing campaign and dynamic identification. Advanced modeling of two case studies allowed demonstrating that these structures have a high vulnerability and require strengthening measures.(undefined

Automated long-term dynamic monitoring using hierarchical clustering and adaptive modal tracking: validation and applications

Historical buildings demand constant surveying because anthropogenic (e.g., use, pollution or traffic vibration) and natural or environmental hazards (e.g., environmental changes or earthquakes) can endanger their existence and safety. Particularly, in the Andean region of South America, earthen historical constructions require special attention and investigation due to the high seismic hazard of the area next to the Pacific coast. Structural Health Monitoring (SHM) can provide useful, real-time information on the condition of these buildings. In SHM, the implementation of automatic tools for feature extraction of modal parameters is a crucial step. This paper proposes a methodology for the automatic identification of the structural modal parameters. An innovative and multi-stage approach for the automatic dynamic monitoring is presented. This approach uses the Data-Driven Stochastic Subspace Identification method complemented by hierarchical clustering for automatic detection of the modal parameters, as well as an adaptive modal tracking procedure for providing a clear visualization of long-term monitoring results. The proposed methodology is first validated in data acquired in an emblematic sixteenth century historical building: the monastery of Jeronimos in Portugal. After proving its efficiency, the algorithm is used to process almost 5000 events containing data acquired in the church of Andahuaylillas, a sixteenth century adobe building located in Cusco, Peru. The results in these cases demonstrate that accurate estimation of predominant modal parameters is possible in those complex structures even if relatively few sensors are installed.The present work was developed thanks to the funding provided by the program Cienciactiva from CONCYTEC in the framework of the Contract no. 222-2015. Complementary funding was also received from the Pontificia Universidad Catolica del Peru PUCP and its funding office DGI-PUCP (project 349-2016). The first author gratefully acknowledges ELARCH program for the scholarship in support of his PhD studies (Project Reference number: 552129-EM-1-2014-1-IT-ERA MUNDUS-394 EMA21)