MARCO CONCEPTUAL DEL TALLER “PONER LÍMITES” PARA PADRES DEL NIVEL INICIAL

Every practice needs a theory that can both enrich each other. Therefore, when I drafted the workshop "Putting Limits" (TPL) aimed at parent`s early education, the first thing I posted was a conceptual framework to guide the practice, and at the same time, parameters to evaluate the results. The TPL originated because teachers identified the main problem to work in classroom to be that students have "no limits" (don`t wait for their turn, bother, ignore, rise without permission, etc.), and their parents have some difficulty in getting their children to obey them. Being a member of GPS / ENSRP, I delved on the subject and reflections I have made based on contributions from other authors. Also, I employed Transactional Analysis which allowed me to develop conceptual assumptions that may enrich dialectically with lines of action and research on this problem by similar workshops in different contexts. However, this paper identifies and evaluates these fundamental concepts

Surrogate modeling for risk-targeted seismic design of isolated structures using friction pendulum systems

Base isolation has been used in the last decades to provide structures with enhanced seismic performance, especially to meet the requirements of risk-critical buildings (e.g., healthcare facilities). This calls for risk-targeted design approaches that consider the explicit computation of various decision variables (e.g., expected annual loss or mean annual frequency of exceeding various damage states). Nonetheless, most of these structures are still designed following implicit risk/reliability considerations derived from building codes. The main hurdle to an explicit risk-based design is the computational effort and time required for seismic performance assessments, given the iterative nature of a typical risk/loss-based design process. This paper proposes using Gaussian-process-regression-based surrogate probabilistic seismic demand models (PSDMs) of equivalent single-degree-of-freedom systems (i.e., the probability distribution of peak horizontal displacements and accelerations on top of the isolation layer conditional on different ground-motion intensity levels) to address these challenges. This enables a risk-targeted methodology for the seismic design of low-rise structures equipped with friction pendulums that virtually requires no design iterations. First, the definition, training, and validation of the surrogate PSDMs are presented. Then, a brief description of a tentative risk-targeted procedure enabled by the proposed surrogate PSDMs is presented. The predictive power of the surrogate PSDMs is verified using a 10-fold cross-validation technique, resulting in normalised root mean square error below 3% for the parameters of the PSDMs and below 7% for their standard deviation

Modelling multi-hazards interactions in life-cycle analysis of engineering systems

Complex engineering systems must be designed to sustain the occurrence of multiple natural and man-made hazards during their service life. To properly quantify multi-hazard effects on the performance of engineering systems, we need to identify the interactions in both occurrence rates of multiple hazards and associated consequences. Recent literature has established a common nomenclature for multi-hazard design, separating occurrence interactions from consequence interactions. In terms of occurrence, hazards are classified as concurrent (if they tend to occur simultaneously) and successive (if one hazard intensifies the occurrence rate of another). In terms of consequences, cascading effects are identified whenever a hazard's occurrence modifies the system's properties, changing the effects of a subsequent hazard. However, the available literature mainly looks at the problem from a qualitative perspective that classifies interactions but does not translate the resulting taxonomy to the mathematical modelling of the hazards and their effects. This paper aims to fill this gap by identifying modelling approaches associated with different hazard interdependencies. In particular, we focus on occurrence interactions, and we develop a simulation-based approach for generating multihazard scenarios (i.e., a sequence of hazard events and associated features through the system’s life cycle) based on the theory of competing Poisson processes. The proposed approach incorporates the different types of interactions in a sequential Monte Carlo sampling method. The method outputs potential sequences of events throughout a system’s life cycle, which can be integrated into LCA frameworks to quantify interacting hazard consequences. A simple application is presented to illustrate the potential of the proposed method

Environmental impacts of seismic damage for a case-study reinforced RC building in Italy

This study evaluates the environmental impacts resulting from the repair of earthquakeinduced damage, considering an older reinforced concrete (RC) frame representative of those built in Italy before the 1970s. Such impacts, expressed in terms of embodied carbon, represent a considerable component of buildings’ life-cycle embodied carbon in seismically-prone regions. Embodied carbon is a metric that measures the total greenhouse gas emissions associated with material extraction, manufacturing, transporting, construction, maintenance, and disposal. The seismic damage sustained by the case-study frame is first evaluated using the FEMA P-58 approach. Specifically, the frame’s nonlinear response is analysed against increasing groundshaking intensities, followed by estimating the damage incurred by its individual components via ad-hoc fragility models. Damage is then converted to embodied carbon by using consequence models specifically derived in this study for Italian structural/non-structural building components. This is accomplished by: 1) collecting environmental-impact data from Italian manufacturers of relevant construction materials and; 2) defining suitable structure-specific damage levels and the required repair work for every component. Results show that the embodied carbon induced by seismic damage throughout the case-study building’s life cycle might exceed 25% of that generated during its initial construction (pre-use phase)

A fragility-oriented approach for seismic retrofit design

This study proposes a practical fragility-oriented approach for the seismic retrofit design of case-study structures. This approach relies on mapping the increase of the global displacement-based ratio of capacity to life-safety demand ( CDRLS) to the building-level fragility reduction. Specifically, the increase of CDRLS due to retrofitting is correlated with the corresponding shift in the fragility median values of multiple structure-specific damage states, observing that a pseudo-linear trend is appropriate under certain conditions. Accordingly, a practical approach is proposed to fit such a (structure-specific) linear trend and then use it by first specifying the desired fragility median and subsequently finding the corresponding target value of CDRLS that must be achieved through retrofit design. The validity of the proposed approach is illustrated for an archetype reinforced concrete (RC) structure not conforming to modern seismic design requirements, which has been retrofitted using various techniques, namely, fiber-reinforced polymers wrapping of columns and joints, RC jacketing, and steel jacketing

Simulation-based consequence models of seismic direct loss and repair time for archetype reinforced concrete frames

Seismic risk management of building portfolios requires a reliable evaluation of earthquake-induced losses. This is commonly performed using consequence models linking structure-specific damage states (DSs) experienced by a building to a given loss metric (or decision variable). This study demonstrates a simulation-based procedure that derives refined probabilistic consequence models considering two essential loss metrics: direct-loss and repair-time ratios (repair cost or time normalised by the corresponding reconstruction values). Nine case-study reinforced concrete frames with various heights and design-code levels are developed to represent common residential buildings in Italy and the Mediterranean region. The proposed procedure starts by defining building-level, structure-specific DSs that reflect the increasing structural and nonstructural damage for the nine frames. Their seismic response is then assessed by analysing two-dimensional nonlinear numerical models and deriving building-level fragility relationships. Next, component-based direct-loss and repair-time analysis is conducted via the FEMA P-58 methodology, which computes such metrics at multiple ground-shaking intensities using Monte Carlo sampling. The consequence models are finally characterised by fitting probabilistic distributions to the direct-loss and repair-time realisations after conditioning them on the respective global DSs sustained by each case-study frame. This procedure enables deriving enhanced consequence models that can be easily implemented in risk analysis of building portfolios to obtain quick loss estimates. This study finally sheds some light on the possibility of correlating repair time to direct loss, which might be useful in estimating indirect losses resulting from downtime, particularly in cases where repair-time data or models are unavailable

Costrutti di PLS-PM di alto ordine per l’analisi di indicatori sociali compositi Un’applicazione alla Customer satisfaction per la riduzione del questionario

Il Progetto di Ricerca si focalizza sulla costruzione di Indicatori Compositi attraverso i Modelli ad Equazioni Strutturali, nello specifico attraverso l'uso dei modelli PLS- Path Modeling. In questo lavoro, dunque, dopo aver presentato vari approcci al PLS-PM di alto ordine, sia già noti in letteratura, sia nuovi sviluppi a cui ho collaborato durante gli anni di dottorato di ricerca, si presenta una applicazione del PLS-PM di alto ordine sulla Customer Satisfaction per la riduzione della lunghezza del questionario. Inoltre si propone un piccolo studio di simulazione per testare la generalizzazione di tale approccio

MARCO CONCEPTUAL DEL TALLER “PONER LÍMITES” PARA PADRES DEL NIVEL INICIAL

Every practice needs a theory that can both enrich each other. Therefore, when I drafted the workshop "Putting Limits" (TPL) aimed at parent`s early education, the first thing I posted was a conceptual framework to guide the practice, and at the same time, parameters to evaluate the results. The TPL originated because teachers identified the main problem to work in classroom to be that students have "no limits" (don`t wait for their turn, bother, ignore, rise without permission, etc.), and their parents have some difficulty in getting their children to obey them. Being a member of GPS / ENSRP, I delved on the subject and reflections I have made based on contributions from other authors. Also, I employed Transactional Analysis which allowed me to develop conceptual assumptions that may enrich dialectically with lines of action and research on this problem by similar workshops in different contexts. However, this paper identifies and evaluates these fundamental concepts