0000000000095646
AUTHOR
Paolo Castaldo
Seismic vulnerability of structures and infrastructures: Strategies for assessment and mitigation
Seismic engineering is constantly looking for new strategies and methods that provide designers with the opportunity to get more and more efficient solutions both from the performance and from the economic point of view. In this context, the scientific community is called not to miss its support and to face the new challenges coming from the observation of the damage caused by the recent earthquakes. This Special Issue of “Ingegneria Sismica” collects some works focusing the theme of the seismic vulnerability, some of them specifically refer to mitigation strategies while others address modeling strategies. Obviously, for the multiplicity of aspects involving the theme of "seismic vulnerabi…
Response spectrum analysis of frame structures: reliability-based comparison between complete quadratic combination and damping-adjusted combination
In the framework of seismic design of structures, response spectrum analysis (RSA) is the most commonly used approach in practice. The most popular combination rule is the complete quadratic combination (CQC) which is also prescribed by the most of seismic design codes and is based on the assumptions that the seismic acceleration is a white noise process and the peak factor ratios associated to the total and modal responses are unitary. Recently, the damping adjusted combination (DAC) rule has been developed for base-isolated structures to overcome the aforementioned simplified assumptions. Although it has been proved that the simplifications about peak factors lead to noticeable errors in …
Full scale tests of the base-isolation system for an emergency hospital
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 …
Hardening structures isolated by double sliding devices: Seismic reliability-based design approach
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…