Search results for "Seismic isolation"
showing 5 items of 5 documents
Strategies of Identification of a Base-Isolated Hospital Building by Coupled Quasi-Static and Snap-Back Tests
2020
In this paper, the description of a series of quasi-static pushing tests and dynamic snap-back tests is proposed, involving the base-isolated emergency building of the Palermo university hospital. The base isolation system is characterized by a set of double-curved friction pendulum isolators placed on the top of the columns of the underground level, characteristics that cannot be found in the experimental studies available in the literature. The aim of the work was to investigate the static and dynamic properties of the building in question and comparing the in-situ results with the characteristics assigned during the design process and to assess the level of agreement. Static lateral push…
Upwards - Vertical extensions of masonry built heritage for sustainable and antifragile urban densification
2021
Abstract Urban densification represents one of the biggest universal challenges of contemporary cities: the increase of urban population requires new spaces to accommodate the growing demand for housing, working and tertiary activities. However, the land available for new constructions in highly urbanized areas is very limited. In this framework, the vertical extension of existing buildings is the most sustainable strategy and fascinating. Masonry structures , constituting a major part of the built stock in the historical city centres of several European countries, are particularly suitable for vertical addition of extra-floors, since they generally exhibit an adequate overstrength for bear…
Hardening structures isolated by double sliding devices: Seismic reliability-based design approach
2019
This study deals with seismic reliability-based design (SRBD) relationships in terms of behavior factors and displacement demands for hardening structures equipped with double friction pendu-lum system (DFPS) bearings. An equivalent 3dof system having a hardening post-yield slope is adopted to describe the superstructure behavior, whereas velocity-dependent laws are assumed to model the responses of the two surfaces of the DFPS. The yielding characteristics of the super-structures are defined for increasing behavior factors in compliance with the seismic hazard of L’Aquila site (Italy) and with NTC18 assuming a lifetime of 50 years. Considering several natural seismic records and building p…
Full scale tests of the base-isolation system for an emergency hospital
2019
The paper presents the results of some full-scale tests regarding the base-isolation system of the emergency room building of the polyclinic hospital in Palermo (Italy). This building has been recently realized and its base isolation system is characterized by double friction pendulum isolators. Static lateral pushing tests were aimed at identifying fundamental mechanical properties of the whole isolation level (e.g. friction forces and stiffness) in order to verify the agreement with the design hypotheses. Further dynamic tests provided different displacements of the isolated base followed by the instantaneous release (snap-back tests), in order to verify the effectiveness, the mechanical …
Intermediate Isolation System for the seismic retrofit of existing masonry buildings
2022
This paper deals with the potentials of Intermediate Isolation Systems (IIS) for retrofitting masonry buildings by means of a vertical extension, isolated at its base, and realized on the rooftop of the existing structure. By carefully defining the dynamic properties of the superstructure and isolation system, in previous papers the authors have demonstrated that this passive technique is able to reduce a priori the seismic demand on the existing building. For this reason, the non-linear behavior has been only assumed for the isolation system, with the masonry structure in the elastic field. This result has been validated by carrying out spectrum-compatible time history analyses on the 3D F…