In occasione del Convegno ANIDIS 2025, è prevista una visita tecnica a Norcia presso alcuni dei principali siti colpiti dal sisma, con l’obiettivo di osservare da vicino le attività di ricostruzione, consolidamento e monitoraggio strutturale in corso.

Per tutte le informazioni di dettaglio relative  a data,  orario, modalità di iscrizione e disponibilità si invita a consultare la sezione 'Eventi del convegno'.

Title: Bradiseism and volcanic hazard at Campi Flegrei, Italy

Abstract: The Phlegraean Fields (Campi Flegrei) are a volcanic caldera formed by the eruptions of the Campanian Ignimbrite (39,000 years ago) and the Yellow Tuff (15,000 years ago). Subsequently, three periods of activity can be distinguished, during which about 70 eruptions occurred, separated by long periods of quiescence. The most recent eruption took place in 1538, and it is well documented through images and historical documents. The typical hazardous eruptive phenomena include the generation of pyroclastic flows, the dispersal and fallout of volcanic ash, and lava flows. More recently, the "bradyseism risk" has been officially recognized, referring to ongoing ground deformation and associated earthquakes in the area. An additional hazard that is now being discussed is the potential occurrence of phreatic explosions, which may be triggered by the rapid depressurization of shallow portions of the hydrothermal system. The presentation will illustrate the various hazards related to the possible opening of new eruptive vents and volcanic eruptions, as well as the damage associated with seismic activity, ground deformation, and gas emissions that occur during bradyseismic crises, such as the one that has been ongoing since 2005.

Title: Performance of Seismically Isolated Structures in Earthquakes.

Abstract: many seismically isolated structures have been constructed, ranging from houses, apartment buildings, hospitals, emergency facilities, architecturally and historically significant structures and tall buildings to large bridges and offshore platforms.  The observation of performance of such structures in earthquakes provides valuable information on the validity of design procedures and on the lifetime behavior of isolators and delivers lessons on actions that are needed to avoid problems and enhance reliability.

The presentation will start with a discussion of design procedures for seismically isolated structures, uncertainty and reliability in design.  This guides the audience to a better understanding of the observed performance of several seismically isolated structures that are presented next.  It is concluded that, in general, the performance of seismically isolated structures is very good but dependent on proper analysis and design, provisions for increased capacities of isolators and superstructures to meet reliability objectives, effective peer review, testing (prototype and production) of isolators, proper construction and inspection.

Title: Digital Twin of the NHERI-UC San Diego 6-DOF Large High-Performance Outdoor Shake Table (LHPOST6)

Abstract: The UC San Diego Large High-Performance Outdoor Shake Table (LHPOST) was commissioned on October 1, 2004, as a shared-use experimental facility under the U.S. National Science Foundation (NSF) Network for Earthquake Engineering Simulation (NEES) program. While originally conceived as a six-degree-of-freedom (6-DOF) system, budget constraints led to its initial construction as a single-degree-of-freedom (1-DOF) shake table. After serving the earthquake engineering community for 15 years, the LHPOST underwent a major upgrade to its originally intended 6-DOF configuration between October 2019 and April 2022, at which point it was renamed the LHPOST6.

A mechanics-based numerical model (i.e., digital twin) of the LHPOST6 was developed. Under bare-table conditions, this model comprises three subsystems: (1) the hydraulic dynamics, (2) the hold-down struts, and (3) the three-dimensional kinematics and dynamics of the mechanical components of the LHPOST6, including the platen and the attached vertical and horizontal actuators. A systematic, step-by-step methodology was established to both calibrate the model parameters and validate the model itself, using an extensive set of experimental data from acceptance and characterization tests.

A dynamic model of the LHPOST6 under loaded-table conditions was developed by coupling three software platforms: (a) the MTS 469D motion controller, (b) the LHPOST6 dynamic model implemented in Simulink, and (c) the nonlinear structural specimen modeled in OpenSees. A numerical algorithm was formulated to solve the nonlinear equations of motion governing the coupled system. This model was validated using data from two landmark research projects recently completed on the LHPOST6: the full-scale 10-story mass timber building tested in the NHERI TallWood project and the full-scale 6-story mass timber building tested in the NHERI Converging Design project. The promising approach of iteratively tuning the shake table controller to optimize tracking of target earthquake ground motions—using the fully numerical model of the coupled LHPOST6-specimen system, thereby avoiding the risk of damaging high-cost test specimens during tuning—was also investigated.

Tilte - Recent Developments in Site Response Analysis and Microzonation

Abstract: The basic purpose of site response analysis is to evaluate possible local site effects and the earthquake characteriscs on the ground surface to estimate probable earthquake damage for the existing building stock and for the design of new structures. The basic issues in the site response analysis are the inherent uncertainty in source characteristics, soil profile, soil properties, and site response analysis procedure. In addition, characteristics of the building inventories would introduce critical uncertainties associated with these analyses. Recent advances, with growing computational capacity, emphasize probabilistic frameworks to capture these uncertainties. The probability distribution of the related earthquake parameters on the ground surface may be determined considering all possible input acceleration time histories, site profiles, and dynamic soil properties. One option to account for the variability in earthquake source and path effects may be to consider using large number of acceleration records compatible with the site-dependent earthquake hazard partially based on  hazard deaggregation at the investigated site. Likewise, stochastic soil profiles generated via Monte Carlo simulations can be used to account for the site condition variability. A comprehensive seismic microzonation methodology is proposed based on the probabilistic assessment of these factors involved in site response analyses. The second important issue is the selection of microzonation parameters. The selection of microzonation parameters—such as Cumulative Absolute Velocity (CAV) and Housner Intensity (HI)—is emphasized for their stronger empirical correlation with structural damage. The main approach is to develop a microzonation procedure for ground shaking intensity accounting for variability in ground motion and soil response. The third issue is the reliability and correctness of the site response analysis procedure. The adopted methodology advances traditional site response analysis by integrating frequency- and stress-dependent soil behavior models to achieve a more accurate numerical model and proposing the use of 3D site response analysis to reflect the multi-directional nature of seismic loading. It also highlights the need for representative time histories with known exceedance probabilities. Even though the selected representative acceleration time histories may be scaled with respect to probabilistic acceleration spectrum or peakground acceleration obtained based on probabilistic site response analysis; the probability of the selected acceleration time histories are not known. The only possible option is to estimate probabilistic acceleration time histories with predetermined exceedance probabilities to enhance fully probabilistic site response analysis. The proposed methodology is demonstrated through case studies based on data from the Istanbul Rapid Response Network, to underline the importance of fully probabilistic site response analysis in seismic microzonation, aiming to improve the reliability of ground motion predictions and support informed decision-making in earthquake engineering.