Analysis of the 2016 Amatrice earthquake macroseismic data

On August 24, 2016, a sudden MW 6.0 seismic event hit central Italy, causing 298 victims and significant damage to residential buildings and cultural heritage. In the days following the mainshock, a macroseismic survey was conducted by teams of the University of Padova, according to the European Macroseismic Scale (EMS98). In this contribution, a critical analysis of the collected macroseismic data is presented and some comparisons were performed with the recent 2012 Emilia sequence

Reliability-based analysis of recycled aggregate concrete under carbonation

Durability represents a crucial issue for evaluating safety and serviceability of reinforced concrete structures. Many studies have already focused on carbonation-induced corrosion of natural aggregate concrete (NAC) structures, leading to several prediction models to estimate carbonation depth. Less research is devoted instead on recycled aggregate concrete (RAC), about which limited experimental works exist aimed at assessing the carbonation coefficient in accelerated tests. Additionally, deteriorating processes are subject to uncertainty, when defining materials, geometry, and environmental actions during the service life of structures. This work presents a reliability-based analysis of carbonation resistance of RACs, using experimental carbonation coefficients derived from the literature, and applied in the full-probabilistic method prosed in fib Bulletin 34. Results demonstrate how aggregates replacement ratio and w/c ratio influence the reliability of RAC carbonation resistance

Municipal expected annual loss as an indicator to develop seismic risk maps in Italy

This work presents a risk-targeted indicator called Municipal Expected Annual Loss (MEAL) for a quantitative estimation of the seismic risk at territorial level. With MEAL, it is possible to calculate the impact of earthquakes in terms of direct losses, taking account of a wide set of earthquake scenarios on the built environment at municipal level. MEAL is, therefore, able to summarize scenario loss values of each municipality, and define in such a way a risk-targeted metric that can clearly be understood also by different stakeholders dealing with seismic risk management, mitigation, and transfer. The use of MEAL to map seismic risk for the Italian residential building stock is herein presented as a case-study, leading to the development of several maps able to depict seismic risk at different territorial scale levels

A framework for probabilistic seismic risk assessment of NG distribution networks

Lifelines are essential infrastructures for human activities and the economic developm ent of a region. Lifelines vulnerability reduction is an actual question, particularly with reference to NaTech events, like earthquakes. In this regard, worldwide past seismic experiences revealed heavy damages to NG distribution networks. It is therefore essential to perform seismic risk assessment of NG buried pipelines systems with the aim to identify potential criticalities and avoid significant consequences. For such reasons, this work illustrates the proposal of a probabilistic framework for seismic risk assessment of NG lifelines. The proposed procedure is subsequently applied to a specific case study in Italy to highlight its feasibility

Center and Characteristic Seismic Reliability as new indexes for accounting uncertainties in seismic reliability analysis

Seismic reliability analysis is a powerful tool to assess structural safety against ground shaking actions induced by earthquake occurrences. The classic approach for computing seismic reliability of a structural system requires a seismic hazard curve and a fragility function and leads to the estimation of the failure probability of the investigated damage state. However, resulting failure probability is strongly related to the preliminary assumptions in both hazard and fragility analyses, and slight changes in the input model parameters may cause relevant variability of seismic reliability estimates. The present work formalizes a general approach to be followed when dealing with seismic reliability assessment of structural systems, aimed at taking into account the whole uncertainties of the input parameters within hazard and fragility models. In the proposed approach, probability of failure becomes in turn a random variable and therefore new indexes are introduced, namely Expected Failure Rate, Failure Rate Dispersion, Characteristic Failure Rate, Center of Seismic Reliability and Characteristic Seismic Reliability. Lastly, such approach is applied to a case study, where seismic reliability of an existing open-spandrel reinforced concrete arch bridge is analyzed, and results are discussed highlighting some relevant issues

Loss assessment models for seismic risk mitigation in structures

Seismic risk can be defined as an inclusive term that encompasses the probability of different ground motions and the related consequences, depending on the structural vulnerability. Seismic risk analysis is a general procedure that usually can consider different indicators, for both a specific structure or at territorial level: among others, for civil structures, risk is expressed in terms of monetary losses, i.e. costs to be sustained for repairing seismic damage or loss of revenue. This work wants to contribute to the current seismic risk assessment approaches with original contributions to the analysis of both point-like and territorial assets, focusing on some aspects, that are still not or poorly treated in literature. Regarding seismic risk analysis for a single specific structure, this work focuses on seismic risk analysis of industrial productive processes, with particular reference to business interruption losses. Recent seismic events, as the Emilia-Romagna earthquake in 2012, showed that such type of indirect losses can be very significant, and therefore a model is proposed to fill this lack of models for assessing indirect losses due to business interruption. Furthermore, a financial framework is also set up to assess the optimal seismic retrofit strategy for productive processes. In regard to the seismic risk analysis at territorial level, a seismic risk map of Italy is developed. Some considerations on historical losses and the implementation of specific earthquake catastrophe funds is also discussed. Finally, a deep insight on Catastrophe bonds (CAT bonds), as financial tool for transferring potential losses arising from natural hazards is illustrated. In particular, a novel reliability-based CAT bond pricing framework is developed, and applied to a case study represented by the Italian residential building portfolio

Seismic behavior of precast reinforced concrete column-to-foundation grouted duct connections

AbstractThe paper shows the results of an experimental campaign aimed at investigating the cyclic behavior of a column-to-foundation joint for precast concrete elements. The tested connection is realized adopting corrugated steel ducts embedded into the foundation, in which column protruding rebars are anchored by grouting high performance mortar. The experimental program consists in testing six full-scale reinforced concrete square-section columns subject to quasi-static cyclic lateral load with a constant axial compression. A preliminary series of bond tests was carried out to define some experimental variables, i.e., longitudinal rebar diameter and anchorage length. Results of the precast joints are compared with those of two reference cast-in-place specimens with the same geometric characteristics, showing similar hysteretic behavior, energy dissipation and ductility values. Lastly, the plastic hinge height is computed for all the specimens based on experimental concrete strains, and compared to current codes formulations

Structural reliability of masonry arch bridges subject to natural aging

This paper deals with a simplified full-probabilistic methodology for the safety assessment of existing masonry arch bridges. The proposed framework aims to determine the ultimate load-carrying capacity (Ultimate Limit State) of a bridge subject to environmental deterioration, and to establish the influence on the structural reliability.- (undefined

Efficacy and Safety of Leadless Pacemaker Implantation in Octogenarians

INTRODUCTION Long-term complication rates in standard transvenous pacemakers are reported around 4-12% with a higher incidence in the elderly population. We report our experience in octogenarians undergoing leadless pacemaker implantation in two large-volume centers in Switzerland. METHODS Consecutive patients undergoing leadless pacemaker implantation at two Swiss large volume centers (University Hospital Zurich, Zurich and Cardiocentro Ticino Institute, Lugano) between October 2015 and March 2020 were included in this retrospective analysis. Demographic information, clinical data, and procedural characteristics were recorded at the day of implantation and during follow-up. RESULTS Two hundred and twenty patients (mean age 80.6 ± 7.7 years, male 66%) were included. The main indication for pacemaker implantation was slow ventricular rate atrial fibrillation (111 of 220 patients, 50.4%). Out of the 220 patients, 124 (56.3%) were ≥80 years. Overall successful implantation rate was 98.6%. In the octogenarian population, the median procedure time (45 ± 20.2 min vs. 40 ± 19.6 min, p = 0.03) and radiation duration (6.1 ± 8.2 min vs. 5.0 ± 7.2 min, p = 0.03) were longer compared to patients <80 years. Major complications (2.7%, n = 6) and device measurements during follow-up were similar between patients ≥80 and <80 years. CONCLUSION Implantation of a leadless pacemaker device in octogenarians is safe and effective with a similarly low complication rate compared to non-octogenarians