Pier Francesco Giordano | Politecnico di Milano (original) (raw)

Conference Papers by Pier Francesco Giordano

Research paper thumbnail of Risk-based bridge scour management: A survey

Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations, Apr 20, 2021

Scour is a major cause of bridge failure and results in significant economic losses through disru... more Scour is a major cause of bridge failure and results in significant economic losses through disruption to operation. This phenomenon naturally affects bridges with underwater foundations and is exacerbated during high river and/or turbulent flows (e.g. due to extreme events). When scour reaches the bottom of or undermines shallow foundations, it may trigger various damage mechanisms that may influence the safety of the structure and force asset managers to reduce traffic capacity. Currently, assessing risk of scour is a heuristic process, heavily reliant on qualitative approaches and expert opinion (e.g. visual inspections). These types of assessments typically suffer from insufficient knowledge of influencing factors (e.g. hydraulic parameters) and the requirement to rely on several assumptions (e.g. assumed foundation depth). As a result, current scour assessment and bridge management practices do not provide reliable solutions for addressing the potential risk of bridge failures. In this paper, cross-cutting needs and challenges related to the development of decision support tools for scour-risk management are highlighted and some preliminary results of a literature survey are reported. The review has been performed with several objectives: (i) identifying scour-risk indicators describing hydrodynamic actions and the asset condition; (ii) defining indirect and direct consequences needed to assess the risks associated to different decision alternatives related to scour management; and (iii) identifying existing approaches to scour inspections and monitoring as support tools for informed decisions. The results of this survey will serve as a base for future research aimed to develop an informed decision support tool to manage scour risk at both the bridge and at the network level.

Papers by Pier Francesco Giordano

Research paper thumbnail of The Benefit of Informed Risk-Based Management of Civil Infrastructures

Infrastructures

One of the most interesting applications of Structural Health Monitoring (SHM) is the possibility... more One of the most interesting applications of Structural Health Monitoring (SHM) is the possibility of providing real-time information on the conditions of civil infrastructures during and following disastrous events, thus supporting decision-makers in prompt emergency operations. The Bayesian decision theory provides a rigorous framework to quantify the benefit of SHM through the Value of Information (VoI) accounting for different sources of uncertainties. This decision theory is based on utility considerations, or, in other words, it is based on risk. Instead, decision-making in emergency management is often based on engineering judgment and heuristic approaches. The goal of this paper is to investigate the impact of different decision scenarios on the VoI. To this aim, a general framework to quantify the benefit of SHM information in emergency management is applied to different decision scenarios concerning bridges under scour and seismic hazards. Results indicate that the consider...

Research paper thumbnail of Impact of Decision Scenarios on the Value of Seismic Structural Health Monitoring

Lecture notes in civil engineering, Jun 19, 2022

Research paper thumbnail of The value of monitoring a structural health monitoring system

Research paper thumbnail of A method to assess the value of monitoring an SHM system

Journal of Physics: Conference Series

Aging structural components, together with the increasing transportation needs and limited budget... more Aging structural components, together with the increasing transportation needs and limited budgets, are challenging aspects that typically concern decision-makers and infrastructure owners. Although Structural Health Monitoring (SHM) has been a powerful tool to optimize maintenance-related activities and post-disaster emergency management, the sensor readout and, therefore, the outcome of the monitoring system is susceptible to errors due to malfunctioning. For years, the Value of Information (VoI) has been studied to quantify the long- term benefit of SHM systems against the initial investment in sensing instrumentation without considering the eventuality of faulty sensing nodes. However, these are very common in field applications. This paper proposes a new framework to calculate the benefit of using Sensor Validation Tools (SVTs) before calculating the damage-sensitive features that drive the SHM process. The novel approach extends the traditional Vol to consider multiple “health...

Research paper thumbnail of Diagnostic investigations and structural health state assessment of San Pietro bell tower in Perugia

10th International Masonry Conference,IMC 2018, 2018

Research paper thumbnail of The benefit of permanent monitoring for seismic emergency management

9th International Conference on Structural Health Monitoring of Intelligent Infrastructure: Transferring Research into Practice, SHMII 2019, Aug 4, 2019

Research paper thumbnail of A Renewal Theory Formulation for the Quantification of the Benefits of Structural Health Monitoring

Lecture Notes in Civil Engineering, 2021

Research paper thumbnail of Response‐based time‐invariant methods for damage localization on a concrete bridge

Structural Concrete, 2020

This paper is integral part of the Special Issue on "Existing Concrete Structures: Structural Hea... more This paper is integral part of the Special Issue on "Existing Concrete Structures: Structural Health Monitoring and Testing for condition assessment." It deals with vibration-based methods (VBMs) for damage localization that approach the problem of structural integrity management through the analysis of the dynamic response of the structure under ambient or forced vibrations. In the last years, these methods received a widespread interest in the structural health monitoring (SHM) community due to the possibility to use them for continuous SHM and real time damage identification. The performance of these methods is commonly verified on numerical models or laboratory specimens that, by their nature, cannot reproduce all the sources of uncertainties found in practice. The availability of data recorded on a real benchmark, the S101 bridge in Austria, enabled the comparison of three well known vibration-based time-invariant methods for damage localization, namely, the curvature method, the interpolation error method, and the strain energy method. The bridge, built in the early 1960, is a typical example of a European highway bridge. Responses to ambient vibrations were recorded both in the undamaged and in several different damage scenarios artificially inflicted to the bridge. This paper reports the results of the application of the three mentioned methods of damage localization to this case study.

Research paper thumbnail of A comparison of the UK and Italian national risk-based guidelines for assessing hydraulic actions on bridges

Structure and Infrastructure Engineering

Research paper thumbnail of On the Effectiveness of Vibration-Based Monitoring for Integrity Management of Prestressed Structures

Infrastructures, 2021

In this paper, the effectiveness of vibration-based tests for the detection of damages for prestr... more In this paper, the effectiveness of vibration-based tests for the detection of damages for prestressed concrete beams is investigated. Despite large research efforts, discrepant and sometimes contradicting conclusions have been drawn regarding the efficacy and reliability of vibration-based monitoring for prestressed structures. Herein, a contribution to this discussion is provided by tackling the problem from a different perspective. Specifically, the question that this paper intends to answer is: “Do vibration-based tests support decision-makers in integrity management operations for prestressed elements?” The discussion is carried out by comparing the performance of prestressed and ordinary reinforced concrete beams with similar capacities. Both analytical and numerical case studies are considered. Results show that, for prestressed beams, in contrast to reinforced concrete beams, modal parameters can provide information regarding damage only when the structure is close to its ul...

Research paper thumbnail of Value of Information analysis for degrading engineering systems

Life-Cycle Civil Engineering: Innovation, Theory and Practice, 2021

Research paper thumbnail of The value of seismic structural health monitoring for post-earthquake building evacuation

Bulletin of Earthquake Engineering, 2022

In the aftermath of a seismic event, decision-makers have to decide quickly among alternative man... more In the aftermath of a seismic event, decision-makers have to decide quickly among alternative management actions with limited knowledge on the actual health condition of buildings. Each choice entails different direct and indirect consequences. For example, if a building sustains low damage in the mainshock but people are not evacuated, casualties may occur if aftershocks lead the structure to fail. On the other hand, the evacuation of a structurally sound building could lead to unnecessary financial losses due to business and occupancy interruption. A monitoring system can provide information about the condition of the building after an earthquake that can support the choice between several competing alternatives, targeting the minimization of consequences. This paper proposes a framework for quantifying the benefit of installing a permanent seismic structural health monitoring (S2HM) system to support building evacuation operations after a seismic event. Decision-makers can use th...

Research paper thumbnail of Use of Sar Satellite Data in Bridge Monitoring with Application to Urban Areas

Lecture Notes in Civil Engineering, 2021

Research paper thumbnail of Quantifying the value of SHM information for bridges under flood-induced scour

Structure and Infrastructure Engineering, 2022

Research paper thumbnail of Vibration Response-Based Damage Detection, Chapter 6/10

This chapter aimed to present different data driven Vibration-Based Methods (VBMs) for Structural... more This chapter aimed to present different data driven Vibration-Based Methods (VBMs) for Structural Health Monitoring (SHM). This family of methods, widely used for engineering applications, present several advantages for damage identification applications. First, VBMs provide continuous information on the health state of the structure at a global level without the need to access the damaged elements and to know their location. Furthermore, damage can be identified using the dynamic response of the structure measured by sensors non-necessarily located in the proximity of damage and without any prior knowledge about the damage location. By principle, VBMs can identify damage related to changes in the dynamic properties of structures, such as stiffness variations due to modifications in the connections between structural elements, or changes in geometric and material properties. A classification of different VBMs was presented in this chapter. Furthermore, several case studies were pres...

Research paper thumbnail of A Survey of Bridge Condition Rating Systems

Lecture Notes in Civil Engineering, 2021

Research paper thumbnail of Comparison of Bridge Inspection Policies in terms of Data Quality

Journal of Bridge Engineering, 2022

Research paper thumbnail of Decision Making Based on the Value of Information of Different Inspection Methods

Structural Health Monitoring 2019, 2019

Decision makers face several challenges in the aftermath of a disastrous event. Emergency operati... more Decision makers face several challenges in the aftermath of a disastrous event. Emergency operations such as traffic restrictions, bridge closures and immediate repairs might have to be scheduled in order to keep an appropriate level of safety. The state of the infrastructure after the occurrence of the seismic event can be predicted based on the a priori knowledge about the system, and decisions may be taken based on this knowledge. This is generally done by minimizing the expected cost of the different plans of action, considering both direct (e.g. failure of a component) and indirect costs (e.g. costs coming from diverted traffic after a bridge closure). However, inspections of selected critical components can provide insight into the actual state of the system and consequently change the chosen plan of action for the decision makers. Different methods of inspections come at different costs, information and uncertainties. It is important to decide whether or not inspections should be done and if so select the most appropriate inspection method so that the associated costs do not overcome the benefits that would be obtained by performing it. Moreover, advanced monitoring techniques that are able to investigate the state of the system over time (such as sensor monitoring) can provide additional information about the way the system is evolving. This information can in turn be used to update the knowledge about the state of the system before the occurrence of a disastrous event, further reducing the chance of taking the wrong managing decision. Before installation, decision makers must properly evaluate the costs associated to these monitoring techniques, to decide whether the additional information overcomes their cost. In this work, we propose a general framework to evaluate the Value of Information of selected inspection procedures considering the possible information from structural health monitoring (SHM) of system. The proposed framework will be applied to a case study of a two-span reinforced concrete bridge. 1

Research paper thumbnail of Comparison of Indicators of Damage Location Based on Information Gain

Structural Health Monitoring 2019, 2019

Vibration-based methods for damage localizations are often based on a damage feature defined in t... more Vibration-based methods for damage localizations are often based on a damage feature defined in terms of changes of modal or operational shapes. These methods allow detecting variations of the damage feature that can be attributed to damage. Many of these methods are based on the detection of irregularities in the modal shapes of the structure. In this paper, the performance of several algorithms for damage localization is investigated and the results are compared both qualitatively, in terms of the capability to correctly localize damage, and quantitatively, in terms of relative information entropy. This parameter quantifies the gain of information obtained a given damage indicators with respect to a reference one. As reference damage indicator is assumed the prior probability of damage defined in terms of expert opinion or as a non-informative parameter. The investigation is carried out using responses simulated using the calibrated finite element model of a real Italian bridge permanently monitored by the Italian Seismic Observatory of Structures.

Research paper thumbnail of Risk-based bridge scour management: A survey

Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations, Apr 20, 2021

Scour is a major cause of bridge failure and results in significant economic losses through disru... more Scour is a major cause of bridge failure and results in significant economic losses through disruption to operation. This phenomenon naturally affects bridges with underwater foundations and is exacerbated during high river and/or turbulent flows (e.g. due to extreme events). When scour reaches the bottom of or undermines shallow foundations, it may trigger various damage mechanisms that may influence the safety of the structure and force asset managers to reduce traffic capacity. Currently, assessing risk of scour is a heuristic process, heavily reliant on qualitative approaches and expert opinion (e.g. visual inspections). These types of assessments typically suffer from insufficient knowledge of influencing factors (e.g. hydraulic parameters) and the requirement to rely on several assumptions (e.g. assumed foundation depth). As a result, current scour assessment and bridge management practices do not provide reliable solutions for addressing the potential risk of bridge failures. In this paper, cross-cutting needs and challenges related to the development of decision support tools for scour-risk management are highlighted and some preliminary results of a literature survey are reported. The review has been performed with several objectives: (i) identifying scour-risk indicators describing hydrodynamic actions and the asset condition; (ii) defining indirect and direct consequences needed to assess the risks associated to different decision alternatives related to scour management; and (iii) identifying existing approaches to scour inspections and monitoring as support tools for informed decisions. The results of this survey will serve as a base for future research aimed to develop an informed decision support tool to manage scour risk at both the bridge and at the network level.

Research paper thumbnail of The Benefit of Informed Risk-Based Management of Civil Infrastructures

Infrastructures

One of the most interesting applications of Structural Health Monitoring (SHM) is the possibility... more One of the most interesting applications of Structural Health Monitoring (SHM) is the possibility of providing real-time information on the conditions of civil infrastructures during and following disastrous events, thus supporting decision-makers in prompt emergency operations. The Bayesian decision theory provides a rigorous framework to quantify the benefit of SHM through the Value of Information (VoI) accounting for different sources of uncertainties. This decision theory is based on utility considerations, or, in other words, it is based on risk. Instead, decision-making in emergency management is often based on engineering judgment and heuristic approaches. The goal of this paper is to investigate the impact of different decision scenarios on the VoI. To this aim, a general framework to quantify the benefit of SHM information in emergency management is applied to different decision scenarios concerning bridges under scour and seismic hazards. Results indicate that the consider...

Research paper thumbnail of Impact of Decision Scenarios on the Value of Seismic Structural Health Monitoring

Lecture notes in civil engineering, Jun 19, 2022

Research paper thumbnail of The value of monitoring a structural health monitoring system

Research paper thumbnail of A method to assess the value of monitoring an SHM system

Journal of Physics: Conference Series

Aging structural components, together with the increasing transportation needs and limited budget... more Aging structural components, together with the increasing transportation needs and limited budgets, are challenging aspects that typically concern decision-makers and infrastructure owners. Although Structural Health Monitoring (SHM) has been a powerful tool to optimize maintenance-related activities and post-disaster emergency management, the sensor readout and, therefore, the outcome of the monitoring system is susceptible to errors due to malfunctioning. For years, the Value of Information (VoI) has been studied to quantify the long- term benefit of SHM systems against the initial investment in sensing instrumentation without considering the eventuality of faulty sensing nodes. However, these are very common in field applications. This paper proposes a new framework to calculate the benefit of using Sensor Validation Tools (SVTs) before calculating the damage-sensitive features that drive the SHM process. The novel approach extends the traditional Vol to consider multiple “health...

Research paper thumbnail of Diagnostic investigations and structural health state assessment of San Pietro bell tower in Perugia

10th International Masonry Conference,IMC 2018, 2018

Research paper thumbnail of The benefit of permanent monitoring for seismic emergency management

9th International Conference on Structural Health Monitoring of Intelligent Infrastructure: Transferring Research into Practice, SHMII 2019, Aug 4, 2019

Research paper thumbnail of A Renewal Theory Formulation for the Quantification of the Benefits of Structural Health Monitoring

Lecture Notes in Civil Engineering, 2021

Research paper thumbnail of Response‐based time‐invariant methods for damage localization on a concrete bridge

Structural Concrete, 2020

This paper is integral part of the Special Issue on "Existing Concrete Structures: Structural Hea... more This paper is integral part of the Special Issue on "Existing Concrete Structures: Structural Health Monitoring and Testing for condition assessment." It deals with vibration-based methods (VBMs) for damage localization that approach the problem of structural integrity management through the analysis of the dynamic response of the structure under ambient or forced vibrations. In the last years, these methods received a widespread interest in the structural health monitoring (SHM) community due to the possibility to use them for continuous SHM and real time damage identification. The performance of these methods is commonly verified on numerical models or laboratory specimens that, by their nature, cannot reproduce all the sources of uncertainties found in practice. The availability of data recorded on a real benchmark, the S101 bridge in Austria, enabled the comparison of three well known vibration-based time-invariant methods for damage localization, namely, the curvature method, the interpolation error method, and the strain energy method. The bridge, built in the early 1960, is a typical example of a European highway bridge. Responses to ambient vibrations were recorded both in the undamaged and in several different damage scenarios artificially inflicted to the bridge. This paper reports the results of the application of the three mentioned methods of damage localization to this case study.

Research paper thumbnail of A comparison of the UK and Italian national risk-based guidelines for assessing hydraulic actions on bridges

Structure and Infrastructure Engineering

Research paper thumbnail of On the Effectiveness of Vibration-Based Monitoring for Integrity Management of Prestressed Structures

Infrastructures, 2021

In this paper, the effectiveness of vibration-based tests for the detection of damages for prestr... more In this paper, the effectiveness of vibration-based tests for the detection of damages for prestressed concrete beams is investigated. Despite large research efforts, discrepant and sometimes contradicting conclusions have been drawn regarding the efficacy and reliability of vibration-based monitoring for prestressed structures. Herein, a contribution to this discussion is provided by tackling the problem from a different perspective. Specifically, the question that this paper intends to answer is: “Do vibration-based tests support decision-makers in integrity management operations for prestressed elements?” The discussion is carried out by comparing the performance of prestressed and ordinary reinforced concrete beams with similar capacities. Both analytical and numerical case studies are considered. Results show that, for prestressed beams, in contrast to reinforced concrete beams, modal parameters can provide information regarding damage only when the structure is close to its ul...

Research paper thumbnail of Value of Information analysis for degrading engineering systems

Life-Cycle Civil Engineering: Innovation, Theory and Practice, 2021

Research paper thumbnail of The value of seismic structural health monitoring for post-earthquake building evacuation

Bulletin of Earthquake Engineering, 2022

In the aftermath of a seismic event, decision-makers have to decide quickly among alternative man... more In the aftermath of a seismic event, decision-makers have to decide quickly among alternative management actions with limited knowledge on the actual health condition of buildings. Each choice entails different direct and indirect consequences. For example, if a building sustains low damage in the mainshock but people are not evacuated, casualties may occur if aftershocks lead the structure to fail. On the other hand, the evacuation of a structurally sound building could lead to unnecessary financial losses due to business and occupancy interruption. A monitoring system can provide information about the condition of the building after an earthquake that can support the choice between several competing alternatives, targeting the minimization of consequences. This paper proposes a framework for quantifying the benefit of installing a permanent seismic structural health monitoring (S2HM) system to support building evacuation operations after a seismic event. Decision-makers can use th...

Research paper thumbnail of Use of Sar Satellite Data in Bridge Monitoring with Application to Urban Areas

Lecture Notes in Civil Engineering, 2021

Research paper thumbnail of Quantifying the value of SHM information for bridges under flood-induced scour

Structure and Infrastructure Engineering, 2022

Research paper thumbnail of Vibration Response-Based Damage Detection, Chapter 6/10

This chapter aimed to present different data driven Vibration-Based Methods (VBMs) for Structural... more This chapter aimed to present different data driven Vibration-Based Methods (VBMs) for Structural Health Monitoring (SHM). This family of methods, widely used for engineering applications, present several advantages for damage identification applications. First, VBMs provide continuous information on the health state of the structure at a global level without the need to access the damaged elements and to know their location. Furthermore, damage can be identified using the dynamic response of the structure measured by sensors non-necessarily located in the proximity of damage and without any prior knowledge about the damage location. By principle, VBMs can identify damage related to changes in the dynamic properties of structures, such as stiffness variations due to modifications in the connections between structural elements, or changes in geometric and material properties. A classification of different VBMs was presented in this chapter. Furthermore, several case studies were pres...

Research paper thumbnail of A Survey of Bridge Condition Rating Systems

Lecture Notes in Civil Engineering, 2021

Research paper thumbnail of Comparison of Bridge Inspection Policies in terms of Data Quality

Journal of Bridge Engineering, 2022

Research paper thumbnail of Decision Making Based on the Value of Information of Different Inspection Methods

Structural Health Monitoring 2019, 2019

Decision makers face several challenges in the aftermath of a disastrous event. Emergency operati... more Decision makers face several challenges in the aftermath of a disastrous event. Emergency operations such as traffic restrictions, bridge closures and immediate repairs might have to be scheduled in order to keep an appropriate level of safety. The state of the infrastructure after the occurrence of the seismic event can be predicted based on the a priori knowledge about the system, and decisions may be taken based on this knowledge. This is generally done by minimizing the expected cost of the different plans of action, considering both direct (e.g. failure of a component) and indirect costs (e.g. costs coming from diverted traffic after a bridge closure). However, inspections of selected critical components can provide insight into the actual state of the system and consequently change the chosen plan of action for the decision makers. Different methods of inspections come at different costs, information and uncertainties. It is important to decide whether or not inspections should be done and if so select the most appropriate inspection method so that the associated costs do not overcome the benefits that would be obtained by performing it. Moreover, advanced monitoring techniques that are able to investigate the state of the system over time (such as sensor monitoring) can provide additional information about the way the system is evolving. This information can in turn be used to update the knowledge about the state of the system before the occurrence of a disastrous event, further reducing the chance of taking the wrong managing decision. Before installation, decision makers must properly evaluate the costs associated to these monitoring techniques, to decide whether the additional information overcomes their cost. In this work, we propose a general framework to evaluate the Value of Information of selected inspection procedures considering the possible information from structural health monitoring (SHM) of system. The proposed framework will be applied to a case study of a two-span reinforced concrete bridge. 1

Research paper thumbnail of Comparison of Indicators of Damage Location Based on Information Gain

Structural Health Monitoring 2019, 2019

Vibration-based methods for damage localizations are often based on a damage feature defined in t... more Vibration-based methods for damage localizations are often based on a damage feature defined in terms of changes of modal or operational shapes. These methods allow detecting variations of the damage feature that can be attributed to damage. Many of these methods are based on the detection of irregularities in the modal shapes of the structure. In this paper, the performance of several algorithms for damage localization is investigated and the results are compared both qualitatively, in terms of the capability to correctly localize damage, and quantitatively, in terms of relative information entropy. This parameter quantifies the gain of information obtained a given damage indicators with respect to a reference one. As reference damage indicator is assumed the prior probability of damage defined in terms of expert opinion or as a non-informative parameter. The investigation is carried out using responses simulated using the calibrated finite element model of a real Italian bridge permanently monitored by the Italian Seismic Observatory of Structures.

Research paper thumbnail of Clump interpolation error for the identification of damage using decentralized sensor networks

Smart Structures and Systems, 2021

Recent developments in the field of smart sensing systems enable performing simple onboard operat... more Recent developments in the field of smart sensing systems enable performing simple onboard operations which are increasingly used for the decentralization of complex procedures in the context of vibration-based structural health monitoring (SHM). Vibration data collected by multiple sensors are traditionally used to identify damage-sensitive features (DSFs) in a centralized topology. However, dealing with large infrastructures and wireless systems may be challenging due to their limited transmission range and to the energy consumption that increases with the complexity of the sensing network. Local DSFs based on data collected in the vicinity of inspection locations are the key to overcome geometric limits and easily design scalable wireless sensing systems. Furthermore, the onboard pre-processing of the raw data is necessary to reduce the transmission rate and improve the overall efficiency of the network. In this study, an effective method for real-time modal identification is use...