Marco Broccardo

Università degli Studi di Trento | UNITN · Department of Civil, Environmental and Mechanical Engineering

This paper proposes an active learning-based Gaussian process (AL-GP) metamodelling method to estimate the cumulative as well as complementary cumulative distribution function (CDF/CCDF) for forward uncertainty quantification (UQ) problems. Within the field of UQ, previous studies focused on developing AL-GP approaches for reliability (rare event p...

This paper studies a non-random-walk Markov Chain Monte Carlo method, namely the Hamiltonian Monte Carlo (HMC) method in the context of Subset Simulation used for reliability analysis. The HMC method relies on a deterministic mechanism inspired by Hamiltonian dynamics to propose samples following a target probability distribution. The method allevi...

Forecasting the spatial distribution of aftershocks in the aftermath of large seismic events is of great importance for improving both our understanding of earthquake triggering and post-disaster management. Recently, DeVries et al.1 attempted to solve this scientific problem by deep learning. Using the area under the curve (AUC) of receiver operat...

This paper presents a preliminary version of a novel structural reliability method based on the combination of the Hamiltonian Monte Carlo Subset Simulation (HMC-SS) and Gaussian process (GP) modeling coupled with an active learning scheme. The method is formulated directly in the original probability space of the input, and no probability transfor...

In this study, we present a Bayesian hierarchical framework to model fluid-induced seismicity. The framework is based on a non-homogeneous Poisson process (NHPP) with a fluid-induced seismicity rate proportional to the rate of injected fluid. The fluid-induced seismicity rate model depends upon a set of physically meaningful parameters, and has bee...

The potentially large spatial footprint of earthquake disasters and the increased concentration of population and values in dense urban areas call for an explicit consideration of seismic risk at a regional, building portfolio level. The relation between the building-level seismic risk and the portfolio-level seismic risk is helpful if one wants to...

Within the performance-based earthquake engineering (PBEE) framework, the fragility model plays a pivotal role. Such a model represents the probability that the engineering demand parameter (EDP) exceeds a certain safety threshold given a set of selected intensity measures (IMs) that characterize the earthquake load. The-state-of-the art methods fo...

Within the performance-based earthquake engineering (PBEE) framework, the fragility model plays a pivotal role. Such a model represents the probability that the engineering demand parameter (EDP) exceeds a certain safety threshold given a set of selected intensity measures (IMs) that characterize the earthquake load. The-state-of-the art methods fo...

Induced seismicity is one of the main factors that reduces societal acceptance of deep geothermal energy exploitation activities, and felt earthquakes are the main reason for closure of geothermal projects. Implementing innovative tools for real-time monitoring and forecasting of induced seismicity was one of the aims of the recently completed COSE...

This paper proposes a Riemannian Manifold Hamiltonian Monte Carlo based subset simulation (RMHMC-SS) method to overcome limitations of existing Monte Carlo approaches in solving reliability problems defined in highly-curved non-Gaussian spaces. RMHMC is based on the second-order geometric information of a probability space. Specifically, it generat...

Global efforts to tame CO2 emissions include the use of renewable energy sources, such as geo-energy harnessing. However, injecting pressurised fluids into the deep underground can induce earthquakes, hence converting CO2-related risk into seismic risk. Induced seismicity hazard is characterised by the overall seismic activity afb that is normalise...

Conventional validation of analytical and numerical models in Earthquake Engineering involves the comparison of numerically simulated response time histories to experimentally obtained benchmark responses to the same earthquake excitations. As the seismic design problem is inherently stochastic, an alternative, statistical, and easier to-pass valid...

A R T I C L E I N F O Keywords: Cyclic soft stimulation Multi-stage hydraulic stimulation Zonal isolation Realtime seismic monitoring Fluid injection induced seismicity Adaptive traffic light system enhanced geothermal systems (EGS) A B S T R A C T Reykjavik is almost entirely heated by geothermal energy. Yet, recent growth of the city significantl...

Rocking motion is sensitive to the boundary and initial conditions of a rocking structure. Thus, the claims that numerical rocking motion models are not only inaccurate, but that all rocking structures behave unpredictably. Hence, rocking is not used as a seismic design approach. This paper revisits the issue of rocking motion unpredictability. Sei...

It has been claimed that numerical rocking motion models are not only inaccurate, but that all rocking structures behave unpredictably. This paper revisits the issue of rocking motion unpredictability and explores whether not the response to a single ground motion, but the statistics of the responses to an ensemble of ground motions is predictable....

The catastrophic consequences of recent NaTech events triggered by earthquakes highlighted the inadequacy of standard approaches to seismic risk assessment of chemical process plants. To date, the risk assessment of such facilities mainly relies on historical data and focuses on uncoupled process components. As a consequence, the dynamic interactio...

This study introduces the evolutionary tail-equivalent linearization method (ETELM) for nonlinear stochastic dynamic analysis. The method builds on the recently developed tail-equivalent linearization method (TELM) and it is designed for the class of evolutionary processes. The original TELM employs a tail-equivalent linear system (TELS) by equatin...

Rocking motion is sensitive to the boundary and initial conditions of a rocking structure, making experiments non-repeatable. Thus, the claims that numerical rocking motion models are not only inaccurate, but that all rocking structures behave unpredictably. Hence, rocking is not used as a seismic design approach. This paper revisits the issue of r...

This study introduces a computational framework for efficient and accurate seismic fragility analysis based on a combination of artificial ground motion modeling, polynomial‐chaos‐based global sensitivity analysis, and hierarchical kriging surrogate modeling. The framework follows the philosophy of the Performance‐Based Earthquake Engineering PEER...

Conventional validation of analytical and numerical models in Earthquake Engineering involves the comparison of numerically simulated response time histories to experimentally obtained benchmark responses to the same earthquake excitations. As the seismic design problem is inherently stochastic, an alternative, statistical and easier-to-pass valida...

The catastrophic consequences of recent NaTech events triggered by earthquakes highlighted the inadequacy of standard approaches to seismic risk assessment of chemical process plants. To date, the risk assessment of such facilities mainly relies on historical data and focuses on uncoupled process components. As a consequence, the dynamic interactio...

This study introduces a computational framework for efficient and accurate seismic fragility analysis based on a combination of artificial ground motion modeling, polynomial-chaos-based global sensitivity analysis, and hierarchical kriging surrogate modeling. The framework follows the philosophy of the Performance-Based Earthquake Engineering PEER...

Aftershock occurrence is the dominant phenomenon observed in seismicity, offering a wealth of data for the statistical learning of the earthquake nucleation process. However, physical interpretability can be biased by a number of well-known pitfalls. In this comment, we show that the study of Terakawa et al. (2020), who concluded that the spatial d...

With the unfolding of the COVID-19 pandemic, mathematical modeling of epidemics has been perceived and used as a central element in understanding, predicting, and governing the pandemic event. However, soon it became clear that long term predictions were extremely challenging to address. In addition, it is still unclear which metric shall be used f...

With the unfolding of the COVID-19 pandemic, mathematical modeling of epidemics has been perceived and used as a central element in understanding, predicting, and governing the pandemic event. However, soon it became clear that long term predictions were extremely challenging to address. Moreover, it is still unclear which metric shall be used for...

Risk measures are tools that enable consistent measurement of financial risk and quantify the risk exposure to an associated hazard. In finance, there is a broad spectrum of risk measures which reflect different asset performance goals and the risk appetite of the decision-maker. In this study, the authors leverage advancements in financial risk ma...

The rapid increase in energy demand in the city of Reykjavik has posed the need for an additional supply of deep geothermal energy. The deep-hydraulic (re-)stimulation of well RV-43 on the peninsula of Geldinganes (north of Reykjavik) is an essential component of the plan implemented by Reykjavik Energy to meet this energy target. Hydraulic stimula...

In the last few years, deep learning has solved seemingly intractable problems, boosting the hope to find approximate solutions to problems that now are considered unsolvable. Earthquake prediction, the Grail of Seismology, is, in this context of continuous exciting discoveries, an obvious choice for deep learning exploration. We reviewed the liter...

Since the early 1900s, numerous research efforts have been devoted to developing quantitative solutions to stochastic mechanical systems. In general, the problem is perceived as solved when a complete or partial probabilistic description on the quantity of interest (QoI) is determined. However, in the presence of complex system behavior, there is a...

Making communities safer requires better tools to identify, quantify, and manage risks. Among the most important tools are stress tests, originally designed to test the risk posed by nuclear power plants. A complementary harmonized multilevel stress test for nonnuclear civil infrastructure systems against natural hazards is proposed. Each stress te...

The rapid increase in energy demand in the city of Reykjavik has posed the need for an additional supply of deep geothermal energy. The deep hydraulic (re-)stimulation of well RV-43 on the peninsula of Geldinganes (north of Reykjavik) is an essential component of the plan implemented by Reykjavik Energy to meet this energy target. Hydraulic stimula...

In the last few years, deep learning has solved seemingly intractable problems, boosting the hope to find approximate solutions to problems that now are considered unsolvable. Earthquake prediction, the Grail of Seismology, is, in this context of continuous exciting discoveries, an obvious choice for deep learning exploration. We review the entire...

Since 2010, the construction of post-tensioned wooden buildings (Pres-Lam) has been growing rapidly worldwide. Pres-Lam technology combines unbonded post-tensioning tendons and supplemental damping devices to provide moment capacity to beam-column, wall-foundation or column-foundation connections. In low seismic areas, designers may choose not to p...

This paper proposes an active learning-based Gaussian process (AL-GP) metamodelling method to estimate the cumulative as well as complementary cumulative distribution function (CDF/CCDF) for forward uncertainty quantification (UQ) problems. Within the field of UQ, previous studies focused on developing AL-GP approaches for reliability (rare event p...

Numerical models developed to predict the seismic response of structures deforming into the inelastic range often fail the conventional validation test: they fail to reproduce the experimentally obtained response to a particular ground motion with acceptable accuracy. This paper claims that this is too strict of a test for seismic response modellin...

This study presents a site-based parameterized stochastic model for simulation of far-field synthetic ground motions. The model employs a modulated and filtered white-noise process defined via spectral representation. The modulating function is a recently proposed non-parametric function based on a monotonic cubic spline interpolation. As for the t...

In the last years, deep learning has solved seemingly intractable problems, boosting the hope to find (approximate) solutions to problems that now are considered unsolvable. Earthquake prediction - a recognized moonshot challenge - is obviously worthwhile exploring with deep learning. Although encouraging results have been obtained recently, deep n...

This package contains the MATLAB codes for the Hamiltonian Monte Carlo based Subset Simulation (HMC-SS) method. The codes work for reliability problems defined in both Gaussian and Non-Gaussian spaces. For Gaussian space problems, one only needs to edit the 'Gfun.m' file to define their own limit-state functions. For non-Gaussian space problems, on...

Discussers (Michel et al.) address the paper “A Framework to Evaluate the Benefit of Seismic Upgrading” written by the coauthors of this response. Discussers present the compliance factor approach to evaluate existing structures and determine the need for a seismic upgrade implemented in the Swiss code SIA 269/8 and compare this approach to the one...

29 August 2018: "Artificial intelligence nails predictions of earthquake aftershocks." This Nature News headline is based on the results of DeVries et al. (2018) who forecasted the spatial distribution of aftershocks using Deep Learning (DL) and static stress feature engineering. Using receiver operating characteristic (ROC) curves and the area und...

The seismic risk associated with deep fluid injection in Enhanced Geothermal Systems can be mitigated by stopping reservoir stimulation when the seismic risk becomes unacceptable or by reducing production flow rates when seismicity occurs during the operational phase. So far, none of these mitigation measures have been included in the Levelized Cos...

The rise in the frequency of anthropogenic earthquakes due to deep fluid injections is posing serious economic, societal, and legal challenges to geo-energy and waste-disposal projects. We propose an actuarial approach to mitigate this risk, first by defining an autonomous decision-making process based on an adaptive traffic light system (ATLS) to...

This paper presents a seismic structural testing protocol intended to maximize the relevance of benchmarks for model validation and calibration obtained via hybrid simulation experiments, by maximizing model discrepancy evaluated against an ab initio computational simulator. A probabilistic model of the ground motion excitation is used to parametri...

An argument of engineers and researchers against the use of rocking as a seismic response modification technique is that the rocking motion of a structure is chaotic and the existing models are incapable of predicting it deterministically. This argument is supported by the documented inability of rocking models to predict the motion of a specimen e...

In Switzerland, in the city of Basel and the canton of St Gallen, two pilot Enhanced Geothermal System (EGS) projects caused two sequences of induced earthquakes with magnitude up to 3.5. Only in Basel, after the largest seismic event, the damage claims were of the order of 7-10 million Swiss Francs. These claims were associated with nonstructural...

Predictability is a design requirement. Oftentimes, researchers argue that rocking motion is chaotic, in the sense that the motion of a rocking block is very sensitive to initial and boundary conditions. Such argument is supported by the inability to deterministically predict the response of a structure that uplifts and rocks to a given earthquake...

Predictabilityisadesignrequirement.Oftentimes,researchersarguethatrockingmotionischaotic,inthesensethatthemotionofarockingoscillatorisverysensitivetoinitialandboundaryconditions.Suchargumentissupportedbytheinabilitytodeterministicallypredicttheresponseofastructurethatupliftsandrockstoagivenearthquakegroundmotionexcitation.Thishaspreventedengineersf...

In Basel and St. Gallen, Switzerland, two pilot enhanced geothermal systems projects caused two sequences of induced earthquakes with magnitude up to 3.5. In Basel, hairline cracks in walls and nonstructural damage arose from the largest of the events. This led to damage claims of approximately 7-10 million of Swiss Francs. It follows that predicti...

Civil infrastructure systems (CISs), such as the electric power supply systems, the water supply and distribution systems, and the cellular communication systems, are the backbones of contemporary societies. Resilient CISs are essential for resilient communities. The Re-CoDeS resilience quantification framework (Resilience-Compositional Demand/Supp...

Water supply and distribution systems provide the (potable) water supply needed by communities for drinking water, hygienic and sanitary reasons, industry and agriculture. The Re-CoDeS frameworks allows to quantify the (seismic) resilience of these systems in a compositional community demand / civil infrastructure system supply approach. The evolut...

Since 2010, it has been observed a significant worldwide increment in the construction of posttensioned timber (Pres-Lam) buildings. Pres-Lam technology combines unbonded post-tensioning tendons and supplemental damping devices to provide moment capacity to beam-column, wall-foundation or column-foundation connections. In low seismic areas, designe...

The rise in the frequency of anthropogenic earthquakes due to deep fluid injections is posing serious economic, societal, and legal challenges to geo-energy and waste-disposal projects. We propose an actuarial approach to mitigate this risk, first by defining an autonomous decision-making process based on an adaptive traffic light system (ATLS) to...

Pilot deep geothermal projects in St. Gallen and Basel, Switzerland, have induced long sequences of low-magnitude earthquakes with individual events up to a moment magnitude of 3.4 (Basel, 2006) and 3.5 (St. Gallen, 2013). In Basel, damage included mainly non-structural damage, e.g. small cosmetic cracks on plaster. Such damage can, however, still...

Civil infrastructure and community systems can be classified into different resilience-related configurations, depending on their post-disaster reaction. After a disaster, the supply capacity of civil infrastructure systems as well as the demand of a community for services and, consequently, effective service consumption, may be impacted in differe...

The rise in the frequency of anthropogenic earthquakes due to deep fluid injections is posing serious economic, societal, and legal challenges to many geo-energy and waste-disposal projects. Existing tools to assess such problems are still inherently heuristic and mostly based on expert elicitation (so-called clinical judgment). We propose, as a co...

An argument of engineers and researchers against the use of rocking as a seismic response modification technique is that the rocking motion of a structure is chaotic and the existing models are incapable of predicting it well. This argument is supported by the documented inability of rocking models to predict the motion of a specimen excited by a s...

Disaster resilience of civil infrastructure systems is essential to security and economic stability of communities. The novel compositional demand/supply resilience framework named Re-CoDeS (Resilience-Compositional Demand/Supply) generalizes the concept of disaster resilience across the spectrum of civil infrastructure systems by accounting not on...

This study presents a novel fully non-stationary stochastic model for simulation of synthetic arrays of ground motion. The model employs a modulated and filtered white-noise process defined via spectral representation. This study is an extension of and improvement upon the previous work of Rezaeian and Der Kiureghian. The proposed model preserves t...

This study serves three purposes: (i) to review a synthesis formula for simulation of band-limited stochastic processes based on the sinc expansion; (ii) to implement this synthesis formula in the tail-equivalent linearization method (TELM); and (iii) to demonstrate increased computational efficiency when the sinc expansion is implemented in this c...

The rocking oscillator has drawn the attention of many researchers since the publication of Housner's [1] seminal paper. As the response of the rocking oscillator is highly non-linear and exhibits negative stiffness [2] many researchers have suggested treating the rocking oscillator as a chaotic system, in the sense that small perturbations of its...

In Basel and St. Gallen, Switzerland, two pilot enhanced geothermal systems projects caused two sequences of induced earthquakes with magnitude up to 3.5. In Basel, hairline cracks in walls and non-structural damage arose from the largest of the events. This led to damage claims of approximately 7-10 millions of Swiss Francs. It follows that predic...

In order to use rocking as a seismic response modification strategy along both directions of seismic excitation, a three-dimensional (3D) rocking model should be developed. Since stepping or rolling rocking structural members out of their initial position is not a desirable performance, a rocking design should not involve these modes of motion. To...

This chapter aims to provide a general prospective of the Tail Equivalent Linearization Method, TELM, by offering a review that starts with the original idea and covers a broad array of developments, including a selection of the most recent developments. The TELM is a linearization method that uses the first-order reliability method (FORM) to defin...

This study serves three purposes: (i) to review appropriate metrics for life safety (ii), to provide the outline of a robust mathematical framework quantifying and comparing risk safety metrics, and (iii) to provide upper bounds for aggregate measures of risk. In recent decades, the significant increase in seismicity caused by anthropogenic activit...

In this study a Bayesian Probabilistic Network (BPN) is presented to assess the community demand for the services provided by civil infrastructure systems during the absorption phase after a major earthquake. The post-disaster evaluation of the demand is a key component for assessing resilience in the compositional demand/supply resilience framewor...