Figure - available from: Remote Sensing
This content is subject to copyright.
Three-dimensional displacement rate of deformation of the Morandi bridge between 2015 and 2018 (in mm/yr). Inferred value of deformation using the Markov chain Monte Carlo (MCMC) approach described in the methodology section. All displacement components refer to the coordinate system at the bottom right. North, West and Up axes are characterized by independent arbitrary scales for visualization purposes. Line of sight displacement rates used as inputs are listed in Table 2. MCMC outputs are listed in Table 3 and Figure 2.
Source publication
We present a methodology for the assessment of possible pre-failure bridge deformations, based on Synthetic Aperture Radar (SAR) observations. We apply this methodology to obtain a detailed 15-year survey of the Morandi bridge (Polcevera Viaduct) in the form of relative displacements across the structure prior to its collapse on August 14th 2018. W...
Similar publications
Nowadays, deep learning (DL) finds application in a large number of scientific fields, among which the estimation and the enhancement of signals disrupted by noise of different natures. In this article, we address the problem of the estimation of the interferometric parameters from synthetic aperture radar (SAR) data. In particular, we combine conv...
Synthetic aperture radar (SAR) is more sensitive to the dielectric properties and structure of the targets and less affected by weather conditions than optical sensors, making it more capable of detecting changes induced by management practices in agricultural fields. In this study, the capability of C-band SAR data for detecting crop seeding and h...
Erosion is a powerful force that has moulded the Earth ever since water has been present on its rocky surface. In its seemingly harmless pursuit, erosion threatens ecosystems, reduces agricultural production, and impacts water quality. When trying to investigate erosion, there is no easy way to identify hotspots, only leaving the possibility of pre...
The TerraSAR-X add-on for Digital Elevation Measurements (TanDEM-X) bistatic system provides high-resolution and high-quality interferometric data for global topographic measurement. Since the twin TanDEM-X satellites fly in a close helix formation, they can acquire approximately simultaneous synthetic aperture radar (SAR) images, so that temporal...
The NASA‐ISRO Synthetic Aperture Radar (NISAR) is a repeat‐pass radar mission that will acquire fully polarimetric SAR data in an innovative acquisition mode known as quasi‐quad pol (QQP). It consists of simultaneously operating a HH/HV and a VH/VV dual‐pol modes in the lowest and upper parts of the transmitted frequency spectrum. Compared to more...
Citations
... The main benefit of this strategy is that maintenance is not done unnecessarily and is therefore cost-efficient; however, Sawnson [40] describes this strategy as a fire-fighting strategy for maintenance planning because maintenance is only done if an asset is almost failing or already failed. These failures could be catastrophic with infrastructural assets, such as the collapse of the Grimburgwal quay wall in Amsterdam [24] or the deadly collapse of the Morandi bridge in Genoa [29]. ...
In this paper, we introduce Multi-Objective Deep Centralized Multi-Agent Actor-Critic (MO- DCMAC), a multi-objective reinforcement learning (MORL) method for infrastructural maintenance optimization, an area traditionally dominated by single-objective reinforcement learning (RL) approaches. Previous single-objective RL methods combine multiple objectives, such as probability of collapse and cost, into a singular reward signal through reward-shaping. In contrast, MO-DCMAC can optimize a policy for multiple objectives directly, even when the utility function is non-linear. We evaluated MO-DCMAC using two utility functions, which use probability of collapse and cost as input. The first utility function is the Threshold utility, in which MO-DCMAC should minimize cost so that the probability of collapse is never above the threshold. The second is based on the Failure Mode, Effects, and Criticality Analysis (FMECA) methodology used by asset managers to asses maintenance plans. We evaluated MO-DCMAC, with both utility functions, in multiple maintenance environments, including ones based on a case study of the historical quay walls of Amsterdam. The performance of MO-DCMAC was compared against multiple rule-based policies based on heuristics currently used for constructing maintenance plans. Our results demonstrate that MO-DCMAC outperforms traditional rule-based policies across various environments and utility functions.
... Therefore, damage to bridges, as in any civil structure, is inherent; however, those constructions can provide many years of surface with adequate maintenance programs and appropriate damage identification processes [7][8][9]. Thus, a periodical monitoring of civil structures called structural health monitoring (SHM) is fundamental for preserving the service life of bridges, and avoiding tragic accidents resulting from damage not being detected in time [10,11]. ...
Highway bridges are crucial civil constructions for the transport infrastructure, which require proper attention from the corresponding institutions of each country and constant financing for their adequate maintenance; this is important because different types of damage can be generated within these structures, caused by natural disasters, among other sources, and the heavy loads they transport every day. Therefore, the development of simple, efficient, and low-cost methods is of vital importance, allowing us to identify damage in a timely manner and avoid bridges collapsing. As reported in a previous work, the wavelet energy accumulation method (WEAM) and its corresponding application in the Rio Papaloapan Bridge (RPB) represented an important advance within the field. Despite identifying damage in bridges with precision and at a low cost, there are several aspects to improve in that method. Therefore, in this work, that method was improved, eliminating several steps, and meaningfully reducing the computational burden by implementing an algorithm based on the Shannon entropy, thus giving way to the new entropy wavelet-based method (EWM). This new method was applied directly with regard to the real-life RPB, in both its healthy and damaged conditions. Also, its corresponding numerical model based on the finite element method in its healthy condition and different damage scenarios were carried out. The results indicate that the new EWM retains the advantages of WEAM, and it allows for damage identification to be completed more efficiently, increasing the precision by approximately 0.11%, and significantly reducing the computing time required to obtain results by 5.67 times.
... The displacements of the Tadcaster Bridge were considered because one of the piers collapsed due to a stream force increment on the flow of the river. Other scholars as [16,17] analyzed the behavior of the Morandi Bridge utilizing data from COSMO-SkyMed, Sentinel-1, and Envisat, covering the period from 2009 to 2018. The results demonstrated that a non-standard InSAR approach detected abnormal displacements in the deck close to the structural element (pier) that failed. ...
... For the study and analysis of the potential risk of the El Carrizo bridge, and to determine the p R , the structural performance of the bridge is simulated considering 10 years with the support of the calculated distribution parameters and velocity. In this case, it was considered a lineal model based on some damages found by other researchers [ 14,16,18,19]. Within this frame of reference, the relationship between time and p R is illustrated in the form of a fragility curve, which is used to estimate the potential index of risk for the structure. To summarize the InSAR risk evaluation approach, Fig. 1 illustrates the flowchart of the proposed risk assessment methodology. ...
During the last decade, Interferometric Synthetic Aperture Radar (InSAR) technology has taken a relevant position in the Structural Health Monitoring (SHM) of built infrastructure as bridges. However, it is still necessary to improve the interpretation of InSAR in the structural evaluation of bridges. Within this context, the capabilities of InSAR for monitoring remotely large zones is one of its main advantages. Then, it could be developed a decision support system for better inspection, maintenance, and rehabilitation plan of bridges that are part of transportation infrastructure systems. Considering the above-mentioned capabilities of InSAR in bridge inspection , in this paper, an alternative risk assessment methodology is proposed to estimate a safety index of bridges using the InSAR time series and a calibrated FE model. The methodology consists of calculating the probability of overpassing some limits calculated by applying stress limits to a FE model following the AASHTO manual. The proposed limits were for service, fracture, and the last one with respect to the statistical value estimated from a reference period of displacements. In the case of the statistical threshold, it was calculated using an inverse process, which means to apply the displacements in the FE model for determining the resulting stress values. This evaluation was developed in the upper fiber of the zone that presents the highest load demand. The implementation of the method using images from Sentinel-1 is demonstrated by the evaluation of the El Carrizo Bridge, which is a cable-stayed bridge that suffered severe structural damage due to a vehicular accident back in 2018. Right after the accident, the El Carrizo Bridge was properly repaired and rehabilitated. With the implementation of InSAR, some of the main findings after the rehabilitation process indicate a relatively low probability of risk. In general, the risk for the next 10 years extracted was under 20%. The resulting stress value was equal to 2.59 MPa, the service limit tensile stress was 3.13 MPa, and the stress fracture was 3.95 MPa. This indicated that the structure is working in an adequate way in terms of operational conditions validating the results obtained based on the proposed methodology.
... Multi-temporal Interferometric Synthetic Aperture Radar (MT-InSAR) is a technique that exploits a stack of interferometric SAR data, to extract measurements of ground surface displacement through the analysis of radar phase echoes. In the past 20 years MT-InSAR has proven to be an effective methodology to measure structural displacement characterizing a diverse set of infrastructure including bridges 15,16 , levees and dams 11,[17][18][19][20][21] . Here we present an extensive multi-geometry cumulative deformation map of the Kakhovka dam in Southern Ukraine, using measurements derived from space-borne MT-InSAR 21 . ...
The Kakhovka Dam on the Dnieper River in Kherson Oblast, Ukraine, was completed in 1956 as the final dam in the Dnieper reservoir cascade. On the morning of June 6th, 2023, a substantial portion of the dam suffered a collapse while under Russian control. This incident was documented through satellite optical and radar images, providing valuable evidence of the dam’s condition. Here we present the results of multi-temporal Interferometric Synthetic Aperture Radar (MT-InSAR) monitoring of the Kakhovka dam. The dam is vital for water management and hydroelectric power generation. Utilizing multi-temporal InSAR (MT-InSAR) data, we assessed the dam deformations prior to the collapse. Our findings indicate movements of the south side, facing the Dniprovska Gulf, compatible with several possible damage mechanisms. This study highlights the significance of employing spaceborne advanced monitoring techniques to detect signs of distress and ensure the stability of critical infrastructure.
... These techniques are widely used for infrastructure and facility monitoring purposes like dams [12][13][14] or tailing site facilities in the mining sector [15]. Recently, with increasing relevance, the discussion on InSAR usability for bridge monitoring is evolving [16][17][18][19][20][21][22][23][24][25]. ...
Structural Health Monitoring (SHM) of civil engineering structures is experiencing an increasing progress in the last decades. The present work focuses on the static behavior of a highway bridge due to environmental temperature effects. The goal of the present study was to test the applicability of the satellite-based synthetic aperture radar interferometry (InSAR) for deformation monitoring of a large, curved highway bridge and to compare the obtained results with alternative measurement techniques like classical geodesy surveying and with an advanced computer simulation. Such a comparison is quite rare and provides an important insight into the accuracy, efficiency and limitations of the InSAR technique in the context of SHM. Especially interesting was the question whether the InSAR technique is suitable for blind monitoring of a cluster of bridges in the region of interest. The present study shows that a pre-knowledge about each structure can be very important for a reliable interpretation of the InSAR measurement results. The second challenge of the study was to overcome several objective difficulties of combining and comparing quite different monitoring techniques that result from different sampling rates, measurement points and other specific features and sensitivities. Nevertheless, a suitable approach has been developed and implemented in the present study for the InSAR and total station measurements, providing new results and important knowledge about novel SHM techniques.
... Over the same years, the engineer also designed the Polcevera bridge, which fell in 2018. After its tragic collapse, synthetic aperture radar (SAR) data collected from satellites up to 2018 were used to detect possible precursors [36][37][38]. Similar SAR techniques were applied to the Bisantis bridge, thereby leading to the detection of the vibration amplitude pattern of the deck [39]. ...
Interferometric radars are widely used for monitoring civil structures. Bridges are critical structures that need to be constantly monitored for the safety of the users. In this work, a frequency-modulated continuous wave (FMCW) multiple-input multiple-output (MIMO) radar was used for monitoring an arched bridge in Catanzaro, Italy. Two measurements were carried out; a first standard measurement was made in a monostatic configuration, while a subsequent measurement was carried out in a multimonostatic configuration in order to retrieve the components of the deck displacement. A method that is able to predict the measurement uncertainty as a function of the multimonostatic geometry is provided, thereby aiming to facilitate the operators in the choice of the proper experimental setup. The multimonostatic measurement revealed a displacement along the horizontal direction that was four times higher than the one along the vertical direction, while the values reported in the literature correspond to a ratio of at most around 0.2. This is the first time that such a large ratio detected by radar has been reported; at any rate, it is compatible with the arched structure of this specific bridge. This case study highlights the importance of techniques that are able to retrieve at least two components of the displacement.
... They directly analyzed the displacements from these images and predicted the occurrence of the partial collapse by finding anomalies in the displacement distribution. Milillo et al. (2019) carried out a research on evaluating the structural conditions of the Morandi Bridge before its partial collapse by applying relatively several SAR images from various satellites. They only observed displacements in the proximity of the damaged region and investigated the feasibility of alarming the partial collapse. ...
... In their research, the authors intended to directly analyze the persistent scatterer deformations in an effort to find anomalies for detecting potential instability risks affecting buildings and infrastructures. Macchiarulo et al. (2021) and Giardina et al. (2019) performed damage assessment analyses for identifying early signs of tunnelling-induced damage to adjacent buildings with different structures, foundations, and position relative to the tunnels by using SAR images from COSMO-SkyMed between 2011 and 2015. They extracted the vertical displacement/deformation samples from multi-temporal InSAR techniques and analyzed them in order to detect the settlement-type damage patterns. ...
... On the other hand, extremely large sizes of SAR images due to covering wide areas in the unit of km, and memory space restrictions for collecting many images are other limitations of this process. The other key challenge of SAR-aided SHM pertains to directly analyzing displacements extracted from satellite images regarding bridges (Selvakumaran et al. 2018;Milillo et al. 2019Qin et al. 2017), buildings (Zhu et al. 2018Macchiarulo et al. 2021;Giardina et al. 2019;Cigna et al. 2014;Di Carlo et al. 2021), and dams Mura et al. 2018;Di Martire et al. 2014;Gama et al. 2020;Jänichen et al. 2022). An important note is that the direct utilization of measured data is not a robust way for SHM. ...
This book offers an in-depth investigation into the complexities of long-term structural health monitoring (SHM) in civil structures, specifically focusing on the challenges posed by small data and environmental and operational changes (EOCs). Traditional contact-based sensor networks in SHM produce large amounts of data, complicating big data management. In contrast, synthetic aperture radar (SAR)-aided SHM often faces challenges with small datasets and limited displacement data. Additionally, EOCs can mimic the structural damage, resulting in false errors that can critically affect economic and safety issues. Addressing these challenges, this book introduces seven advanced unsupervised learning methods for SHM, combining AI, data sampling, and statistical analysis. These include techniques for managing datasets and addressing EOCs. Methods range from nearest neighbor searching and Hamiltonian Monte Carlo sampling to innovative offline and online learning frameworks, focusing on data augmentation and normalization. Key approaches involve deep autoencoders for data processing and novel algorithms for damage detection. Validated using simulated data from the I-40 Bridge, USA, and real-world data from the Tadcaster Bridge, UK, these methods show promise in addressing SAR-aided SHM challenges, offering practical tools for real-world applications. The book, thereby, presents a comprehensive suite of innovative strategies to advance the field of SHM.
... This method is helpful when the study area is inaccessible for practical or legal reasons. Satellite interferometry (Franceschetti and Lanari 1999) has been widely used in many scientific fields, ranging from archeology (Tapete and Cigna 2019) to the study of natural hazards like subsidence (Caló et al. 2017;Grassi et al. 2022), earthquakes (Carnemolla et al. 2023;Fielding et al. 2014;Giordano et al. 2023;Massonnet et al. 1993; Thompson and Wright 2002), landslides (García- Bovenga et al. 2012;Confuorto et al. 2017;García-Davalillo et al. 2014;Khalili et al. 2023;Solari et al. 2020), sinkholes (Esposito et al. 2021;Galve et al. 2015;Rispoli et al. 2020), floods (Geudtner, Winter, and Vachon 1996;Kussul, Shelestov, and Skakun 2011;Pierdicca et al. 2013;Pulvirenti et al. 2016), mining areas (Ammirati et al. 2020;Hu et al. 2021), buildings and dams (Costantini et al. 2016;Giardina et al. 2019;Liao et al. 2009;Macchiarulo et al. 2021;Mele, Vitiello, et al. 2022;, and infrastructures (Ma et al. 2022;Macchiarulo et al. 2022;Milillo et al. 2019;Perissin, Wang, and Lin 2012). SAR satellite constellations are well known to be capable of providing all-weather imaging (Battagliere et al. 2019;Pierdicca et al. 2013), making them useful for disaster response and environmental monitoring (Caltagirone et al. 2010;Covello et al. 2010). ...
SAR (Synthetic Aperture Radar) satellite interferometry is a helpful remote sensing technique for large areas analyses and monitoring, especially where the study area is difficult to access for practical or for legal reasons. As a result, the use of these techniques has significantly increased over the past three decades. Among the available different satellite constellations displaying different spatial and temporal resolutions, COSMO-SkyMed of the Italian Space Agency (ASI) represents a cutting-edge reality. COSMO-SkyMed constellation, launched in 2007 by ASI, is a valuable Earth observation tool that provides all-weather, day-and-night imaging capabilities with high resolution and a short revisit time. In this study, we produced an atlas for the entire Italian peninsula using two parameters (R-Index and Percentage of measurability of movement), in order to evaluate the quality and a-priori applicability of satellite interferometry data collected by the COSMO-SkyMed constellation. The atlas was obtained by means of the implementation of different model builders in the GIS (Geographical Information Systems) environment, providing a semi-automatic way to generate the above-mentioned outputs. The R-Index describes the likelihood of detecting Permanent Scatterers in mountainous areas, while the Percentage of measurability of movement indicates the percentage of real motion that interferometry can detect at a certain point in the analyzed region. A high-detail Digital Terrain Model (DTM) has been used to identify the most suitable areas for satellite interferometry monitoring and studying. The results of our analysis showed that the R-Index and the Percentage of measurability of movement could be used to pre-evaluate the quality of satellite interferometry data collected by the COSMO-SkyMed constellation. This research has important implications for disaster response, environmental monitoring, and scientific research and is one of a few cases in the world in which a unified representation for an entire country is provided.
... However, it is worth noting that in the case of temporally or spatially fast varying deformations, the DIn-SAR technique may fail in correctly detecting the overall magnitude of displacements. This leads to an underestimation of the deformation measurements or even the absence of data [28]. Recent studies demonstrated that some improvement of the methodology for the assessment of single structure deformations phenomena could be obtained by combining COSMO-SkyMed (CSK) and Sentinel (SNT) InSAR measurements to evaluate millimetre scale deformation processes [28]. ...
... This leads to an underestimation of the deformation measurements or even the absence of data [28]. Recent studies demonstrated that some improvement of the methodology for the assessment of single structure deformations phenomena could be obtained by combining COSMO-SkyMed (CSK) and Sentinel (SNT) InSAR measurements to evaluate millimetre scale deformation processes [28]. A numerical and experimental campaign was conducted as part of the ReLUIS 2019-2021 and 2022-2024 projects (WP6 structural health monitoring and satellite data) developed under the Italian Civil Protection Department agreement. ...
Continuous monitoring of the structural health of strategic structures and transport infrastructures plays a crucial role in providing an effective assessment of the safety conditions and in timely planning of the ordinary and extraordinary maintenance programme. Deformation monitoring and dynamic characteristic identification are some commonly used strategies for this purpose. One of the main challenges of recent years in the field of structural health monitoring is the use of data deriving from satellite interferometry, capable of providing information on structural deformations at a local and territorial scale. Despite the solidity and dependability of satellite-based methods for assessing ground deformation over time, when it comes to structural surveillance, there are certain circumstances under which satellites are incapable of accurately assessing displacements. This is particularly true for structures that are sensitive to temperature variations. The paper uses the “Ponte della Musica–Armando Trovajoli” in Rome as a case study to explore these aspects in more depth. This bridge has a steel arch structure with a prestressed concrete deck below it. It represents an example in which satellite differential interferometry does not allow obtaining useful information on displacement, at least for the most deformable portion of the deck, and therefore also on any pathological movements. This work proposes a 3D digital twin of the bridge, appropriately calibrated through experimental measurements of the environmental vibrations performed on the bridge. This will allow to evaluate the role played by thermal deformations related to air temperature variations and thus better understand the connection between physiological deformations and satellite limits.
... The 2013 collapse of the eight-story Rana Plaza Savar, Dhaka, Bangladesh, resulted in >1,100 deaths (24). On 2018 August 14, the Morandi bridge in Genoa, Italy collapsed over the Polcevera river, causing 43 deaths (25). The July 2021 12-story building collapse in Miami, FL, claimed the lives of 98 people (26). ...
... The exploitation of deformation signals from interferometric synthetic aperture radar (InSAR) has proved effective in assessing at-risk populations (9,33) and monitoring infrastructure resilience, e.g. roads, railways, bridges, airports, dams, and levees (19,25,(34)(35)(36)(37)(38). Here, we investigate the exposure of communities, assets, and 14 infrastructure systems/facilities (roads, railways, dams, levees, train stations, airports/airfields, universities, schools, hospitals, nursing homes, fire departments, post offices, libraries, and police stations) to subsidence hazards within 100 km inland of the US east coast. ...
Coastal communities are vulnerable to multihazards, which are exacerbated by land subsidence. On the US east coast, the high density of population and assets amplifies the region's exposure to coastal hazards. We utilized measurements of vertical land motion rates obtained from analysis of radar datasets to evaluate the subsidence-hazard exposure to population, assets, and infrastructure systems/facilities along the US east coast. Here, we show that 2,000 to 74,000 km2 land area, 1.2 to 14 million people, 476,000 to 6.3 million properties, and >50% of infrastructures in major cities such as New York, Baltimore, and Norfolk are exposed to subsidence rates between 1 and 2 mm per year. Additionally, our analysis indicates a notable trend: as subsidence rates increase, the extent of area exposed to these hazards correspondingly decreases. Our analysis has far-reaching implications for community and infrastructure resilience planning, emphasizing the need for a targeted approach in transitioning from reactive to proactive hazard mitigation strategies in the era of climate change.
