http://repositorio.lnec.pt:8080/jspui/handle/123456789/1007773 2026-10-26T10:18:58Z http://repositorio.lnec.pt:8080/jspui/handle/123456789/1019475 3D Shaking Table Tests Of A Full Scale 2-Storey Building With Fiber-Reinforced Elastomeric Isolators Losanno, D.; Prakash, S.; Medaglia, P.; Parisi, F.; Konstantinidis, D.; Tubaldi, E.; Ahmadi, H.; Strauss, A.; De Domenico, D.; Vamvatsikos, D.; Lachanas, C.; Vassiliou, M.; Ribeiro, F.; Correia, A.A. Gerard J. O’Reilly; Gian Michele Calvi During the last two decades fiber-reinforced elastomeric isolators (FREIs) emerged as a promising option to reduce both the cost and weight of rubber bearings. The project ERIES-FREISUST (Fiber-Reinforced Elas-tomeric Isolators for seismic resilient structures with SUSTainable Solu-tions) aims to demonstrate the reliability of FREIs in limiting damage to structural and nonstructural components and contents. Two FREI systems were designed for a full-scale 2-story reinforced concrete (RC) infilled frame, differing in standardization and cost levels, namely a Virgin-rubber Carbon-fiber FREI (VC-FREI) and a Reclaimed-rubber Polyester-fiber FREI (RP-FREI). These isolation systems were installed in unbonded con-figuration at the base of the building and tested at the ST3D shaking table facility of Laboratorio Nacional de Engenharia Civil (LNEC), Lisbon, Por-tugal. The novel base-isolation systems demonstrated lateral stability and re-centering capability, as well as adequate vertical stiffness and load-bearing capacity under different ground motions. RP-FREIs were designed and tested up to a design displacement of 105mm corresponding to 150% shear strain. Due to recessing plates VC-FREIs were tested with higher scaling factors compared to RP-FREIs showing higher displacement capaci-ty with negligible residual. The building had no minor damage after the whole testing sequence with contents undergoing limited accelerations and displacements thus ensuring functionality even after major earthquakes. 2025-05-01T00:00:00Z http://repositorio.lnec.pt:8080/jspui/handle/123456789/1019470 Nonlinear response analyses of a 2-storey RC building with fibre-reinforced elastomeric isolators Medaglia, P.; Losanno, D.; Parisi, F.; Lachanas, C.; Ribeiro, F.; Correia, A.A. M. Papadrakakis; M. Fragiadakis Base isolation (BI) is one of the most promising techniques for seismic risk mitigation. How-ever, the high cost of traditional isolators undermines the systematic implementation of BI sys-tems in both new and existing buildings. In the last decade, fibre-reinforced elastomeric isolators (FREIs) have been developed as a promising low-cost alternative to steel reinforced elastomeric isolators. This study presents a numerical investigation on a three-dimensional, two-storey reinforced concrete (RC) frame designed for gravity loads only, which is representa-tive of a recurrent situation in many existing European buildings even in earthquake-prone areas. The specimen was base isolated with innovative FREIs and was subjected to shaking table tests at LNEC, Lisbon, Portugal, within the ERIES-FREISUST research project. This pa-per presents the main outcomes of the numerical modelling of the building specimen. In a first stage, the building was analyzed through a pushover analysis in fixed-based configuration to identify the global seismic capacity, damage progression, and collapse mechanism. The influ-ence of infill walls along one horizontal direction was also addressed by the model, showcasing its significant contribution to the lateral resistance. The FREI BI system was designed to achieve a target isolation period lower than 2 s. Assuming a Bouc-Wen hysteretic model of FREIs, which was calibrated based on experimental tests, the specimen response was investi-gated via nonlinear time history analysis (NLTHA). Based on the expected displacement ca-pacity of the BI devices, both ordinary and pulse-like ground motion records were selected to be representative of medium-to-high seismicity regions and to finely tune the performance level of FREIs. Both horizontal components of ground motions were imposed to the model. NLTHA demonstrated adequate filtering effect of the isolation system with no damage to both structural and non-structural building components, confirming the experimental observations from the shaking table tests and the effectiveness of FREIs for applications to housing projects. 2025-06-01T00:00:00Z http://repositorio.lnec.pt:8080/jspui/handle/123456789/1019468 Shaking table tests of a 2-storey R.C. building with fiber-reinforced elastomeric isolators Losanno, D.; Prakash, S.; Parisi, F.; Konstantinidis, D.; Tubaldi, E.; Ahmadi, H.; Strauss, A.; De Domenico, D.; Vassiliou, M.; Vamvatsikos, D.; Ribeiro, F.; Correia, A.A. M. Papadrakakis; M. Fragiadakis The Turkey-Syria earthquake on February 6, 2023, reaffirmed that residential buildings in less developed countries exhibit higher vulnerability, resulting in disproportionate fatalities compared to those in developed countries. Due to the well-known effectiveness of base isolation in seismic risk mitigation, recent decades have seen concerted research efforts to drastically reduce the cost of isolation units, making them affordable for housing projects. In this context, fiber-reinforced elastomeric isolators (FREIs) emerged as a promising option to reduce both the cost and weight of rubber bearings by replacing the steel shims conventionally used in laminated bearings with fiber mesh fabric. Although a number of previous studies explored the mechanical behavior and the design process of FREIs, showcasing their effectiveness, experimental validation on a full-scale prototype building subjected to tri-directional excitation remained elusive, thus hindering further development and real-world application. The project ERIES-FREISUST (Fiber-Reinforced Elastomeric Isolators for seismic resilient structures with SUSTainable Solutions) aims to demonstrate the reliability of FREIs in limitng damage to structural and nonstructural components and contents. Two FREI systems were designed for a 2-story reinforced concrete infilled frame, differing in standardization and cost levels, namely a Virgin-rubber Carbon-fiber FREI (VC-FREI) and a Reclaimed-rubber Polyester-fiber FREI (RP-FREI). These isolation systems were installed in an unbonded configuration at the base of the prototype building and tested at the ST3D shaking table facility of Laboratorio Nacional de Engenharia Civil (LNEC), Lisbon, Portugal. This paper reports the preliminary results of the experimental investigation on the base isolated prototype subjected to 3D shaking table tests. The novel base-isolation systems demonstrated lateral stability and re-centering capability, as well as adequate vertical stiffness and load-bearing capacity under different loading conditions. 2025-06-01T00:00:00Z http://repositorio.lnec.pt:8080/jspui/handle/123456789/1019466 Finite element analysis of self-centering beam-to-column subassemblies in seismic-resilient steel MRF: preliminary evaluation of the frame expansion effects Roumieh, A.; Moderini, L.K.; Elettore, E.; Di Benedetto, S.; Francavilla, A.B.; Latour, M.; Gutierrez Urzua, F.; Pieroni, L.; Ramhormozian, S.; Simpson, B.; Barbosa, A.R.; Rizzano, G.; Grant, D.; Ribeiro, F.; Correia, A.A.; Freddi, F. M. Papadrakakis; M. Fragiadakis 2025-06-01T00:00:00Z