This paper reports the preliminary results of a research project (RINTC-E) aimed at computing the risk of collapse in RC precast industrial buildings designed according to the codes in force in Italy in Seventies and Nineties. Companion papers describe the overall research project, funded by the Italian Civil Protection Department, its different areas of application (reinforced concrete, masonry, steel buildings, etc), and the overall seismic risk calculation procedure. This paper describes the design, modelling and pushover nonlinear analyses of one-story precast RC building, designed according to codes in force in Italy in Seventies. The structural nonlinear behavior is modeled using a lumped plasticity approach and the beam-to-column connection is based on friction forces. Collapse of the building is evaluated considering two failure conditions: i) 50% degradation of the maximum base shear recorded on the pushover curve; ii) beam-to-column connection failure. 2796 COMPDYN 2019 7 th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering M. Papadrakakis, M. Fragiadakis (eds.

Old precast buildings are often characterized by poor detailing that may hamper the structural performance particularly in the case of earthquakes. This is essentially related to: (i) a limited past knowledge of seismic design and behaviour, also reflected in past building codes; (ii) the evolution of seismic zonation of the Italian territory. The aim of this work is assessing the probabilistic seismic vulnerability with respect to the usability preventing damage and global collapse performance levels of four existing single-story precast buildings designed in accordance with past Italian building codes from 1960s to 1990s in three sites with increasing seismic hazard.

As widely known, connections performance under seismic loads can significantly affect the structural response of RC precast buildings. Within the scientific community, an increasing number of studies has been carried out on this topic, in the light of the recent earthquake aftermaths all over Europe. Indeed, connections turned out to be the weakest part of the precast structures and their failure often provoked the global collapse of the whole building. The present study aims at assessing the seismic behavior of a single-story RC precast building in terms of global collapse implementing two different models of the beam-to-column connection, a simplified and a refined one. A lumped plasticity approach is used to simulate the structural nonlinear behavior at the column base. In order to assess the refined connection model, a preliminary scheme with an isolated single dowel is validated by comparing the pushover outcomes with experimental results from literature. Nonlinear static and dynamic analyses are performed on two models of a 3D single-story RC precast building, one implementing the simple beam-to-column connection model and the other one implementing the refined mode. The comparison clearly shows that the differences are negligible if the global collapse limit state is considered.

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Structural joints are generally the most critical parts of RC precast structures in terms of seismic assessment, especially in existing buildings, where friction connections can be often found. This issue, widely highlighted in the aftermath of recent earthquakes in Europe, have brought the scientific community to develop retrofitting techniques improving the seismic performance of the connections. The presented work deals with a dissipative hysteretic device, made of two steel rods, arranged as a three-hinged arch, and provided with moon sickle shaped items. It is applied at the beam-to-column connection level and it is intended for both restraining the relative displacements between the joined structural elements and dissipating energy coming from the earthquake. In the presented study, the innovative device is described in detail along with its numerical model, as applied to an existing single-story RC precast structure with beam-to-column friction connections. The results of preliminary numerical analysis showing its efficiency are also reported. COMPDYN 2021 8 th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering M. Papadrakakis, M. Fragiadakis (eds.