{"id":8287,"date":"2025-05-15T10:56:37","date_gmt":"2025-05-15T08:56:37","guid":{"rendered":"https:\/\/ingenius.ecoledesponts.fr\/?p=8287"},"modified":"2025-05-15T14:26:30","modified_gmt":"2025-05-15T12:26:30","slug":"monitoring-damage-to-railway-tracks","status":"publish","type":"post","link":"https:\/\/ingenius.ecoledesponts.fr\/en\/articles\/monitoring-damage-to-railway-tracks\/","title":{"rendered":"Monitoring damage to railway tracks"},"content":{"rendered":"\n\n\n
\"\"
Cobra Robot. Ph : Gilles Foret.<\/figcaption><\/figure>\n\n\n\n

In 2013, the derailment of an Intercit\u00e9s train in Br\u00e9tigny-sur-Orge, in the Essonne department of France, killed 7 people and injured dozens more. Although the primary cause was a loose fishplate (a metal bar used to join two consecutive rails), the investigation also revealed a general lack of maintenance\u2014particularly excessive compaction of the ballast and subgrade\u2014which may have contributed to the deterioration of the track geometry.<\/p>\n\n\n\n

This accident illustrates the importance of regular monitoring of track conditions is crucial to ensure passenger safety and the smooth operation of the rail network. Over time, natural wear and tear caused by weather conditions, frequent train traffic and constant vibrations can lead to deformation or subsidence of track ballast, as well as damage to sleepers and connecting elements. If such damage is not detected in time, it can lead to serious accidents. Poor track condition can also lead to service slow-downs or interruptions, affecting thousands of passengers and goods. Preventive maintenance enables issues to be anticipated before they become critical, to extend the service life of tracks and optimize maintenance costs.<\/p>\n\n\n\n

Ballast or concrete: two different types of track<\/h2>\n\n\n\n

In the railway sector, there are two main types of track: conventional track, laid on ballast1<\/a><\/sup>, and slab track, installed on a concrete structure.<\/p>\n\n\n\n

Conventional tracks are more common on surface, moderate-speed conventional lines, or in rural areas. They offer the advantage of lower cost than slab track, ease of local maintenance (ballast replacement or tamping) and good adaptability, as they are easier to lay in non-standard areas (curves, junctions, etc.).<\/p>\n\n\n\n

With very low maintenance requirements, high stability and a long service life (50 years or more), slab track tracks are preferred for high-speed lines, in constrained environments such as tunnels, and in urban areas (metro).<\/p>\n\n\n\n

However, contrary to what you might think, the majority of TGV lines in France are not equipped with slab track, but with ballasted track. This is partly because France has extensive expertise in the construction and maintenance of ballasted track, developed over several decades. French engineers know how to adapt and maintain this type of track to meet the requirements of high-speed rail.<\/p>\n\n\n\n

What’s more, the cost of building this type of track is significantly lower\u2014up to 30 to 50% less\u2014than that of slab track. Over the long distances typical of TGV lines (often several hundred kilometers), this difference results in substantial cost savings.<\/p>\n\n\n\n

A robot to automatically detect any damage2<\/a><\/sup><\/h2>\n\n\n\n

Underground rail infrastructures are increasingly adopting slab tracks, such as the Low Vibration Track (LVT) system, designed and developed by Roger Sonneville in collaboration with Swiss Federal Railways (SBB) in the 1960s. This system is comprised of concrete blocks mounted on resilient block pads and inserted in rubber boots, which are then embedded in concrete slabs. LVT is used in the Channel Tunnel for example, and offers advantages in terms of vibration reduction and comfort, but poses significant challenges for monitoring and maintenance. Cracks and other damage to concrete blocks are difficult to detect, as they are often concealed within the system. Unidentified damage, however, can compromise safety and generate high costs.<\/p>\n\n\n\n

To address this issue, the Navier laboratory has developed a rapid, non-destructive detection method, in partnership with Eurotunnel. This method is based on modal analysis, a technique that involves vibrating the material – in this case, by striking the blocks with a small hammer – and then measuring the vibrations using a sensor called an accelerometer. By studying the way blocks vibrate (their \u201cnatural frequencies\u201d) and their ability to absorb vibrations, it is possible to detect anomalies.<\/p>\n\n\n\n

The results indicate that the presence of cracks in blocks significantly alters their vibrational behavior, especially in the first bending and torsional modes\u2014i.e., their fundamental deformation patterns, such as bending or twisting. Three types of blocks were studied: new, cracked and broken. Modeling3<\/a><\/sup> confirmed the experimental results, establishing a clear link between the type of crack and the decrease in frequencies. <\/p>\n\n\n\n

This method has been patented and integrated into a software tool called EuroDetection. It led to the design of a robot called COBRA (COntrol of Blocks for Reporting and Analysis) which automates this detection process. This robot travels along the tracks, taking measurements and assessing the condition of blocks in real time during night-time maintenance operations in the tunnel. Finally, to study the evolution of the tracks over time, we used the Wave Finite Element (WFE) coupling method.<\/p>\n\n\n\n

This method efficiently models transition zones between different track structures, reducing computational costs by leveraging track periodicity. Specifically, it allows for the integration of degraded blocks within intact sections and enables numerical simulation of track evolution to identify blocks requiring replacement. Replacing these elements affects adjacent intact blocks, which may become overloaded when trains pass.<\/strong><\/p>\n\n\n\n

\"\"<\/a>
The Cobra robot travels along the tracks, taking measurements and assessing the condition of blocks in real time during night-time maintenance operations in the tunnel. Video author: Gilles Foret (Researcher at Navier Laboratory)<\/figcaption><\/figure>\n\n\n\n

Detecting defects on ballasted tracks4<\/a><\/sup> <\/h2>\n\n\n\n

Monitoring track geometry is essential to ensure passenger safety and comfort, while keeping maintenance costs under control. Such monitoring currently relies on the sporadic use of specialized, costly measurement trains. To overcome these limitations, the Navier laboratory and SNCF are exploring an innovative alternative: the use of accelerometers installed on commercial trains to identify defects in track geometry.<\/p>\n\n\n\n

The idea is to analyze the accelerations measured at the axleboxes (the parts that connect the wheels) to reconstruct track geometry, in particular vertical defects such as bumps or hollows, known as leveling defects and the left-hand side (defect d2 in the figure below).<\/p>\n\n\n\n

The conventional method relies on double integration of acceleration signals. However, this approach comprises several sources of error, including complex axlebox movements (transfers, rotations, inclinations), the influence of train dynamics, variations in ballast and sleeper rigidity in different zones, and imperfect orientation of accelerometers. These factors affect the accuracy of measurements.<\/p>\n\n\n\n

\"\"
The four types of track defects. Credit : M. Chihaoui<\/figcaption><\/figure>\n\n\n\n

<\/p>\n\n\n\n

To overcome these difficulties, the researchers developed an improved reconstruction method. This takes into account more elements that distort the measurements, such as the effects of gravity and centrifugal forces, and adjusts the data according to the actual orientation of the sensors. It draws in particular on differences in acceleration between the left-hand and right-hand sensors to better estimate axle inclination. Tested on real data, this new method produces significantly more reliable results, by reducing the discrepancies between estimates and actual track geometry. <\/p>\n\n\n\n

The study was then extended to a type of defect that is more difficult to detect: lateral defects, i.e. irregularities that deviate the track to the left or to the right (defect d3<\/sub> and d4<\/sub> in the figure above). For this purpose, a model was developed, taking into consideration the train body, the track layout and its irregularities. By inverting this model and analyzing the kinematics (movement) of the axle, it has been shown that lateral offset can be estimated from the axle’s lateral position and swaying – the fact that it tilts slightly to one side. These two measures can be obtained using the accelerometer measurements, combined with knowledge of the track curvature.<\/p>\n\n\n\n

Towards smarter, more sustainable rail maintenance<\/h2>\n\n\n\n

The work carried out at the Navier laboratory illustrates the wealth of possible approaches, combining refined modeling, experimentation and technological development. Whether detecting invisible damage to concrete blocks on slab tracks using modal analysis and robotization, or accurately reconstructing geometric defects on ballasted tracks using on-board sensors, this research is paving the way for more predictive, more efficient and less intrusive maintenance techniques. It is helping to modernize inspection practices, while reducing costs and the impact on operations.<\/strong><\/p>\n\n\n\n

<\/p>\n\n\n

  1. A bed of crushed stone placed under and around the sleepers of a railroad track to stabilize the rails, drain water, distribute train loads and dampen vibrations. \u21a9\ufe0e<\/a><\/li>
  2. D. Gonzalez, B. Claudet, T. Hoang, G. Foret, D. Duhamel \u21a9\ufe0e<\/a><\/li>
  3. Modeling for finished elements with the ABAQUS software \u21a9\ufe0e<\/a><\/li>
  4. https:\/\/hal.science\/hal-04610951\/document<\/a> \u21a9\ufe0e<\/a><\/li><\/ol>","protected":false},"excerpt":{"rendered":"

    In 2013, the derailment of an Intercit\u00e9s train in Br\u00e9tigny-sur-Orge, in the Essonne department of France, killed 7 people and […]<\/p>\n","protected":false},"author":6,"featured_media":8260,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_related_content_post":[],"_related_content_subject":[936],"_related_content_author":[8307,8308],"_related_content_category":[1716],"_related_content_folder":[8304],"_excerpt":"Monitoring the condition of railway tracks is vital for safety and the smooth flow of traffic. Wear and tear caused by the weather, frequent train traffic and vibrations can lead to deformation of the track ballast, as well as damage to sleepers and connecting elements. Without prompt maintenance, this damage can lead to serious accidents, slow-downs and interrupted services.","_duration":6,"_manual_duration":false,"footnotes":"[{\"content\":\"A bed of crushed stone placed under and around the sleepers of a railroad track to stabilize the rails, drain water, distribute train loads and dampen vibrations.\",\"id\":\"a15d4a5a-6c26-43af-8d49-b2f8153681d6\"},{\"content\":\"D. Gonzalez, B. Claudet, T. Hoang, G. Foret, D. Duhamel\",\"id\":\"9d5b11b4-21b5-408a-9a77-edd58e433831\"},{\"content\":\"Modeling for finished elements with the ABAQUS software\",\"id\":\"064f1238-4b6d-4dd1-bb7a-7f4f5601aa2e\"},{\"content\":\"https:\/\/hal.science\/hal-04610951\/document<\/a>\",\"id\":\"25f045e7-7b96-43c0-b125-c33cc03bc9d1\"}]"},"article-types":[13,27],"class_list":["post-8287","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","article-types-article","article-types-folder"],"has_blocks":true,"block_data":[{"blockName":"enpc\/excerpt","attrs":{"lock":[],"metadata":[],"className":"","style":""},"innerBlocks":[],"innerHTML":"","innerContent":[],"rendered":""},{"blockName":"core\/image","attrs":{"id":8260,"width":"497px","height":"auto","sizeSlug":"full","linkDestination":"none","align":"center","blob":"","url":"https:\/\/ingenius.ecoledesponts.fr\/wp-content\/uploads\/2025\/05\/Cobra_G.Foret_.jpg","alt":"","caption":"Cobra Robot. Ph : Gilles Foret.","lightbox":[],"title":"","href":"","rel":"","linkClass":"","aspectRatio":"","scale":"","linkTarget":"","lock":[],"metadata":[],"className":"wp-block-image aligncenter size-full is-resized","style":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    \"\"
    Cobra Robot. Ph : Gilles Foret.<\/figcaption><\/figure>\n","innerContent":["\n
    \"\"
    Cobra Robot. Ph : Gilles Foret.<\/figcaption><\/figure>\n"],"rendered":"\n
    \"\"
    Cobra Robot. Ph : Gilles Foret.<\/figcaption><\/figure>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"In 2013, the derailment of an Intercit\u00e9s train in Br\u00e9tigny-sur-Orge, in the Essonne department of France, killed 7 people and injured dozens more. Although the primary cause was a loose fishplate (a metal bar used to join two consecutive rails), the investigation also revealed a general lack of maintenance\u2014particularly excessive compaction of the ballast and subgrade\u2014which may have contributed to the deterioration of the track geometry.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    In 2013, the derailment of an Intercit\u00e9s train in Br\u00e9tigny-sur-Orge, in the Essonne department of France, killed 7 people and injured dozens more. Although the primary cause was a loose fishplate (a metal bar used to join two consecutive rails), the investigation also revealed a general lack of maintenance\u2014particularly excessive compaction of the ballast and subgrade\u2014which may have contributed to the deterioration of the track geometry.<\/p>\n","innerContent":["\n

    In 2013, the derailment of an Intercit\u00e9s train in Br\u00e9tigny-sur-Orge, in the Essonne department of France, killed 7 people and injured dozens more. Although the primary cause was a loose fishplate (a metal bar used to join two consecutive rails), the investigation also revealed a general lack of maintenance\u2014particularly excessive compaction of the ballast and subgrade\u2014which may have contributed to the deterioration of the track geometry.<\/p>\n"],"rendered":"\n

    In 2013, the derailment of an Intercit\u00e9s train in Br\u00e9tigny-sur-Orge, in the Essonne department of France, killed 7 people and injured dozens more. Although the primary cause was a loose fishplate (a metal bar used to join two consecutive rails), the investigation also revealed a general lack of maintenance\u2014particularly excessive compaction of the ballast and subgrade\u2014which may have contributed to the deterioration of the track geometry.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"This accident illustrates the importance of regular monitoring of track conditions is crucial to ensure passenger safety and the smooth operation of the rail network. Over time, natural wear and tear caused by weather conditions, frequent train traffic and constant vibrations can lead to deformation or subsidence of track ballast, as well as damage to sleepers and connecting elements. If such damage is not detected in time, it can lead to serious accidents. Poor track condition can also lead to service slow-downs or interruptions, affecting thousands of passengers and goods. Preventive maintenance enables issues to be anticipated before they become critical, to extend the service life of tracks and optimize maintenance costs.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    This accident illustrates the importance of regular monitoring of track conditions is crucial to ensure passenger safety and the smooth operation of the rail network. Over time, natural wear and tear caused by weather conditions, frequent train traffic and constant vibrations can lead to deformation or subsidence of track ballast, as well as damage to sleepers and connecting elements. If such damage is not detected in time, it can lead to serious accidents. Poor track condition can also lead to service slow-downs or interruptions, affecting thousands of passengers and goods. Preventive maintenance enables issues to be anticipated before they become critical, to extend the service life of tracks and optimize maintenance costs.<\/p>\n","innerContent":["\n

    This accident illustrates the importance of regular monitoring of track conditions is crucial to ensure passenger safety and the smooth operation of the rail network. Over time, natural wear and tear caused by weather conditions, frequent train traffic and constant vibrations can lead to deformation or subsidence of track ballast, as well as damage to sleepers and connecting elements. If such damage is not detected in time, it can lead to serious accidents. Poor track condition can also lead to service slow-downs or interruptions, affecting thousands of passengers and goods. Preventive maintenance enables issues to be anticipated before they become critical, to extend the service life of tracks and optimize maintenance costs.<\/p>\n"],"rendered":"\n

    This accident illustrates the importance of regular monitoring of track conditions is crucial to ensure passenger safety and the smooth operation of the rail network. Over time, natural wear and tear caused by weather conditions, frequent train traffic and constant vibrations can lead to deformation or subsidence of track ballast, as well as damage to sleepers and connecting elements. If such damage is not detected in time, it can lead to serious accidents. Poor track condition can also lead to service slow-downs or interruptions, affecting thousands of passengers and goods. Preventive maintenance enables issues to be anticipated before they become critical, to extend the service life of tracks and optimize maintenance costs.<\/p>\n"},{"blockName":"core\/heading","attrs":{"style":{"elements":{"link":{"color":{"text":"var:preset|color|red"}}}},"textColor":"red","textAlign":"","content":"Ballast or concrete: two different types of track","level":2,"levelOptions":[],"placeholder":"","lock":[],"metadata":[],"align":"","className":"wp-block-heading has-red-color has-text-color has-link-color","backgroundColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Ballast or concrete: two different types of track<\/h2>\n","innerContent":["\n

    Ballast or concrete: two different types of track<\/h2>\n"],"rendered":"\n

    Ballast or concrete: two different types of track<\/h2>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"In the railway sector, there are two main types of track: conventional track, laid on ballast1, and slab track, installed on a concrete structure.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    In the railway sector, there are two main types of track: conventional track, laid on ballast1<\/a><\/sup>, and slab track, installed on a concrete structure.<\/p>\n","innerContent":["\n

    In the railway sector, there are two main types of track: conventional track, laid on ballast1<\/a><\/sup>, and slab track, installed on a concrete structure.<\/p>\n"],"rendered":"\n

    In the railway sector, there are two main types of track: conventional track, laid on ballast1<\/a><\/sup>, and slab track, installed on a concrete structure.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"Conventional tracks are more common on surface, moderate-speed conventional lines, or in rural areas. They offer the advantage of lower cost than slab track, ease of local maintenance (ballast replacement or tamping) and good adaptability, as they are easier to lay in non-standard areas (curves, junctions, etc.).","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Conventional tracks are more common on surface, moderate-speed conventional lines, or in rural areas. They offer the advantage of lower cost than slab track, ease of local maintenance (ballast replacement or tamping) and good adaptability, as they are easier to lay in non-standard areas (curves, junctions, etc.).<\/p>\n","innerContent":["\n

    Conventional tracks are more common on surface, moderate-speed conventional lines, or in rural areas. They offer the advantage of lower cost than slab track, ease of local maintenance (ballast replacement or tamping) and good adaptability, as they are easier to lay in non-standard areas (curves, junctions, etc.).<\/p>\n"],"rendered":"\n

    Conventional tracks are more common on surface, moderate-speed conventional lines, or in rural areas. They offer the advantage of lower cost than slab track, ease of local maintenance (ballast replacement or tamping) and good adaptability, as they are easier to lay in non-standard areas (curves, junctions, etc.).<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"With very low maintenance requirements, high stability and a long service life (50 years or more), slab track tracks are preferred for high-speed lines, in constrained environments such as tunnels, and in urban areas (metro).","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    With very low maintenance requirements, high stability and a long service life (50 years or more), slab track tracks are preferred for high-speed lines, in constrained environments such as tunnels, and in urban areas (metro).<\/p>\n","innerContent":["\n

    With very low maintenance requirements, high stability and a long service life (50 years or more), slab track tracks are preferred for high-speed lines, in constrained environments such as tunnels, and in urban areas (metro).<\/p>\n"],"rendered":"\n

    With very low maintenance requirements, high stability and a long service life (50 years or more), slab track tracks are preferred for high-speed lines, in constrained environments such as tunnels, and in urban areas (metro).<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"However, contrary to what you might think, the majority of TGV lines in France are not equipped with slab track, but with ballasted track. This is partly because France has extensive expertise in the construction and maintenance of ballasted track, developed over several decades. French engineers know how to adapt and maintain this type of track to meet the requirements of high-speed rail.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    However, contrary to what you might think, the majority of TGV lines in France are not equipped with slab track, but with ballasted track. This is partly because France has extensive expertise in the construction and maintenance of ballasted track, developed over several decades. French engineers know how to adapt and maintain this type of track to meet the requirements of high-speed rail.<\/p>\n","innerContent":["\n

    However, contrary to what you might think, the majority of TGV lines in France are not equipped with slab track, but with ballasted track. This is partly because France has extensive expertise in the construction and maintenance of ballasted track, developed over several decades. French engineers know how to adapt and maintain this type of track to meet the requirements of high-speed rail.<\/p>\n"],"rendered":"\n

    However, contrary to what you might think, the majority of TGV lines in France are not equipped with slab track, but with ballasted track. This is partly because France has extensive expertise in the construction and maintenance of ballasted track, developed over several decades. French engineers know how to adapt and maintain this type of track to meet the requirements of high-speed rail.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"What's more, the cost of building this type of track is significantly lower\u2014up to 30 to 50% less\u2014than that of slab track. Over the long distances typical of TGV lines (often several hundred kilometers), this difference results in substantial cost savings.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    What's more, the cost of building this type of track is significantly lower\u2014up to 30 to 50% less\u2014than that of slab track. Over the long distances typical of TGV lines (often several hundred kilometers), this difference results in substantial cost savings.<\/p>\n","innerContent":["\n

    What's more, the cost of building this type of track is significantly lower\u2014up to 30 to 50% less\u2014than that of slab track. Over the long distances typical of TGV lines (often several hundred kilometers), this difference results in substantial cost savings.<\/p>\n"],"rendered":"\n

    What's more, the cost of building this type of track is significantly lower\u2014up to 30 to 50% less\u2014than that of slab track. Over the long distances typical of TGV lines (often several hundred kilometers), this difference results in substantial cost savings.<\/p>\n"},{"blockName":"core\/heading","attrs":{"style":{"elements":{"link":{"color":{"text":"var:preset|color|red"}}}},"textColor":"red","textAlign":"","content":"A robot to automatically detect any damage2","level":2,"levelOptions":[],"placeholder":"","lock":[],"metadata":[],"align":"","className":"wp-block-heading has-red-color has-text-color has-link-color","backgroundColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    A robot to automatically detect any damage2<\/a><\/sup><\/h2>\n","innerContent":["\n

    A robot to automatically detect any damage2<\/a><\/sup><\/h2>\n"],"rendered":"\n

    A robot to automatically detect any damage2<\/a><\/sup><\/h2>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"Underground rail infrastructures are increasingly adopting slab tracks, such as the Low Vibration Track (LVT) system, designed and developed by Roger Sonneville in collaboration with Swiss Federal Railways (SBB) in the 1960s. This system is comprised of concrete blocks mounted on resilient block pads and inserted in rubber boots, which are then embedded in concrete slabs. LVT is used in the Channel Tunnel for example, and offers advantages in terms of vibration reduction and comfort, but poses significant challenges for monitoring and maintenance. Cracks and other damage to concrete blocks are difficult to detect, as they are often concealed within the system. Unidentified damage, however, can compromise safety and generate high costs.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Underground rail infrastructures are increasingly adopting slab tracks, such as the Low Vibration Track (LVT) system, designed and developed by Roger Sonneville in collaboration with Swiss Federal Railways (SBB) in the 1960s. This system is comprised of concrete blocks mounted on resilient block pads and inserted in rubber boots, which are then embedded in concrete slabs. LVT is used in the Channel Tunnel for example, and offers advantages in terms of vibration reduction and comfort, but poses significant challenges for monitoring and maintenance. Cracks and other damage to concrete blocks are difficult to detect, as they are often concealed within the system. Unidentified damage, however, can compromise safety and generate high costs.<\/p>\n","innerContent":["\n

    Underground rail infrastructures are increasingly adopting slab tracks, such as the Low Vibration Track (LVT) system, designed and developed by Roger Sonneville in collaboration with Swiss Federal Railways (SBB) in the 1960s. This system is comprised of concrete blocks mounted on resilient block pads and inserted in rubber boots, which are then embedded in concrete slabs. LVT is used in the Channel Tunnel for example, and offers advantages in terms of vibration reduction and comfort, but poses significant challenges for monitoring and maintenance. Cracks and other damage to concrete blocks are difficult to detect, as they are often concealed within the system. Unidentified damage, however, can compromise safety and generate high costs.<\/p>\n"],"rendered":"\n

    Underground rail infrastructures are increasingly adopting slab tracks, such as the Low Vibration Track (LVT) system, designed and developed by Roger Sonneville in collaboration with Swiss Federal Railways (SBB) in the 1960s. This system is comprised of concrete blocks mounted on resilient block pads and inserted in rubber boots, which are then embedded in concrete slabs. LVT is used in the Channel Tunnel for example, and offers advantages in terms of vibration reduction and comfort, but poses significant challenges for monitoring and maintenance. Cracks and other damage to concrete blocks are difficult to detect, as they are often concealed within the system. Unidentified damage, however, can compromise safety and generate high costs.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"To address this issue, the Navier laboratory has developed a rapid, non-destructive detection method, in partnership with Eurotunnel. This method is based on modal analysis, a technique that involves vibrating the material - in this case, by striking the blocks with a small hammer - and then measuring the vibrations using a sensor called an accelerometer. By studying the way blocks vibrate (their \u201cnatural frequencies\u201d) and their ability to absorb vibrations, it is possible to detect anomalies.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    To address this issue, the Navier laboratory has developed a rapid, non-destructive detection method, in partnership with Eurotunnel. This method is based on modal analysis, a technique that involves vibrating the material - in this case, by striking the blocks with a small hammer - and then measuring the vibrations using a sensor called an accelerometer. By studying the way blocks vibrate (their \u201cnatural frequencies\u201d) and their ability to absorb vibrations, it is possible to detect anomalies.<\/p>\n","innerContent":["\n

    To address this issue, the Navier laboratory has developed a rapid, non-destructive detection method, in partnership with Eurotunnel. This method is based on modal analysis, a technique that involves vibrating the material - in this case, by striking the blocks with a small hammer - and then measuring the vibrations using a sensor called an accelerometer. By studying the way blocks vibrate (their \u201cnatural frequencies\u201d) and their ability to absorb vibrations, it is possible to detect anomalies.<\/p>\n"],"rendered":"\n

    To address this issue, the Navier laboratory has developed a rapid, non-destructive detection method, in partnership with Eurotunnel. This method is based on modal analysis, a technique that involves vibrating the material - in this case, by striking the blocks with a small hammer - and then measuring the vibrations using a sensor called an accelerometer. By studying the way blocks vibrate (their \u201cnatural frequencies\u201d) and their ability to absorb vibrations, it is possible to detect anomalies.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"The results indicate that the presence of cracks in blocks significantly alters their vibrational behavior, especially in the first bending and torsional modes\u2014i.e., their fundamental deformation patterns, such as bending or twisting. Three types of blocks were studied: new, cracked and broken. Modeling3 confirmed the experimental results, establishing a clear link between the type of crack and the decrease in frequencies. ","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    The results indicate that the presence of cracks in blocks significantly alters their vibrational behavior, especially in the first bending and torsional modes\u2014i.e., their fundamental deformation patterns, such as bending or twisting. Three types of blocks were studied: new, cracked and broken. Modeling3<\/a><\/sup> confirmed the experimental results, establishing a clear link between the type of crack and the decrease in frequencies. <\/p>\n","innerContent":["\n

    The results indicate that the presence of cracks in blocks significantly alters their vibrational behavior, especially in the first bending and torsional modes\u2014i.e., their fundamental deformation patterns, such as bending or twisting. Three types of blocks were studied: new, cracked and broken. Modeling3<\/a><\/sup> confirmed the experimental results, establishing a clear link between the type of crack and the decrease in frequencies. <\/p>\n"],"rendered":"\n

    The results indicate that the presence of cracks in blocks significantly alters their vibrational behavior, especially in the first bending and torsional modes\u2014i.e., their fundamental deformation patterns, such as bending or twisting. Three types of blocks were studied: new, cracked and broken. Modeling3<\/a><\/sup> confirmed the experimental results, establishing a clear link between the type of crack and the decrease in frequencies. <\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"This method has been patented and integrated into a software tool called EuroDetection. It led to the design of a robot called COBRA (COntrol of Blocks for Reporting and Analysis) which automates this detection process. This robot travels along the tracks, taking measurements and assessing the condition of blocks in real time during night-time maintenance operations in the tunnel. Finally, to study the evolution of the tracks over time, we used the Wave Finite Element (WFE) coupling method.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    This method has been patented and integrated into a software tool called EuroDetection. It led to the design of a robot called COBRA (COntrol of Blocks for Reporting and Analysis) which automates this detection process. This robot travels along the tracks, taking measurements and assessing the condition of blocks in real time during night-time maintenance operations in the tunnel. Finally, to study the evolution of the tracks over time, we used the Wave Finite Element (WFE) coupling method.<\/p>\n","innerContent":["\n

    This method has been patented and integrated into a software tool called EuroDetection. It led to the design of a robot called COBRA (COntrol of Blocks for Reporting and Analysis) which automates this detection process. This robot travels along the tracks, taking measurements and assessing the condition of blocks in real time during night-time maintenance operations in the tunnel. Finally, to study the evolution of the tracks over time, we used the Wave Finite Element (WFE) coupling method.<\/p>\n"],"rendered":"\n

    This method has been patented and integrated into a software tool called EuroDetection. It led to the design of a robot called COBRA (COntrol of Blocks for Reporting and Analysis) which automates this detection process. This robot travels along the tracks, taking measurements and assessing the condition of blocks in real time during night-time maintenance operations in the tunnel. Finally, to study the evolution of the tracks over time, we used the Wave Finite Element (WFE) coupling method.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"This method efficiently models transition zones between different track structures, reducing computational costs by leveraging track periodicity. Specifically, it allows for the integration of degraded blocks within intact sections and enables numerical simulation of track evolution to identify blocks requiring replacement. Replacing these elements affects adjacent intact blocks, which may become overloaded when trains pass.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    This method efficiently models transition zones between different track structures, reducing computational costs by leveraging track periodicity. Specifically, it allows for the integration of degraded blocks within intact sections and enables numerical simulation of track evolution to identify blocks requiring replacement. Replacing these elements affects adjacent intact blocks, which may become overloaded when trains pass.<\/strong><\/p>\n","innerContent":["\n

    This method efficiently models transition zones between different track structures, reducing computational costs by leveraging track periodicity. Specifically, it allows for the integration of degraded blocks within intact sections and enables numerical simulation of track evolution to identify blocks requiring replacement. Replacing these elements affects adjacent intact blocks, which may become overloaded when trains pass.<\/strong><\/p>\n"],"rendered":"\n

    This method efficiently models transition zones between different track structures, reducing computational costs by leveraging track periodicity. Specifically, it allows for the integration of degraded blocks within intact sections and enables numerical simulation of track evolution to identify blocks requiring replacement. Replacing these elements affects adjacent intact blocks, which may become overloaded when trains pass.<\/strong><\/p>\n"},{"blockName":"core\/image","attrs":{"lightbox":{"enabled":false},"id":8270,"sizeSlug":"large","linkDestination":"custom","align":"center","blob":"","url":"https:\/\/ingenius.ecoledesponts.fr\/wp-content\/uploads\/2025\/05\/image-1024x576.png","alt":"","caption":"The Cobra robot travels along the tracks, taking measurements and assessing the condition of blocks in real time during night-time maintenance operations in the tunnel. Video author: Gilles Foret (Researcher at Navier Laboratory)","title":"","href":"https:\/\/www.youtube.com\/watch?v=0Zljflh1txs","rel":" noreferrer noopener","linkClass":"","width":"","height":"","aspectRatio":"","scale":"","linkTarget":"_blank","lock":[],"metadata":[],"className":"wp-block-image aligncenter size-large","style":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    \"\"<\/a>
    The Cobra robot travels along the tracks, taking measurements and assessing the condition of blocks in real time during night-time maintenance operations in the tunnel. Video author: Gilles Foret (Researcher at Navier Laboratory)<\/figcaption><\/figure>\n","innerContent":["\n
    \"\"<\/a>
    The Cobra robot travels along the tracks, taking measurements and assessing the condition of blocks in real time during night-time maintenance operations in the tunnel. Video author: Gilles Foret (Researcher at Navier Laboratory)<\/figcaption><\/figure>\n"],"rendered":"\n
    \"\"<\/a>
    The Cobra robot travels along the tracks, taking measurements and assessing the condition of blocks in real time during night-time maintenance operations in the tunnel. Video author: Gilles Foret (Researcher at Navier Laboratory)<\/figcaption><\/figure>\n"},{"blockName":"core\/heading","attrs":{"style":{"elements":{"link":{"color":{"text":"var:preset|color|red"}}}},"textColor":"red","textAlign":"","content":"Detecting defects on ballasted tracks4 ","level":2,"levelOptions":[],"placeholder":"","lock":[],"metadata":[],"align":"","className":"wp-block-heading has-red-color has-text-color has-link-color","backgroundColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Detecting defects on ballasted tracks4<\/a><\/sup> <\/h2>\n","innerContent":["\n

    Detecting defects on ballasted tracks4<\/a><\/sup> <\/h2>\n"],"rendered":"\n

    Detecting defects on ballasted tracks4<\/a><\/sup> <\/h2>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"Monitoring track geometry is essential to ensure passenger safety and comfort, while keeping maintenance costs under control. Such monitoring currently relies on the sporadic use of specialized, costly measurement trains. To overcome these limitations, the Navier laboratory and SNCF are exploring an innovative alternative: the use of accelerometers installed on commercial trains to identify defects in track geometry.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Monitoring track geometry is essential to ensure passenger safety and comfort, while keeping maintenance costs under control. Such monitoring currently relies on the sporadic use of specialized, costly measurement trains. To overcome these limitations, the Navier laboratory and SNCF are exploring an innovative alternative: the use of accelerometers installed on commercial trains to identify defects in track geometry.<\/p>\n","innerContent":["\n

    Monitoring track geometry is essential to ensure passenger safety and comfort, while keeping maintenance costs under control. Such monitoring currently relies on the sporadic use of specialized, costly measurement trains. To overcome these limitations, the Navier laboratory and SNCF are exploring an innovative alternative: the use of accelerometers installed on commercial trains to identify defects in track geometry.<\/p>\n"],"rendered":"\n

    Monitoring track geometry is essential to ensure passenger safety and comfort, while keeping maintenance costs under control. Such monitoring currently relies on the sporadic use of specialized, costly measurement trains. To overcome these limitations, the Navier laboratory and SNCF are exploring an innovative alternative: the use of accelerometers installed on commercial trains to identify defects in track geometry.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"The idea is to analyze the accelerations measured at the axleboxes (the parts that connect the wheels) to reconstruct track geometry, in particular vertical defects such as bumps or hollows, known as leveling defects and the left-hand side (defect d2 in the figure below).","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    The idea is to analyze the accelerations measured at the axleboxes (the parts that connect the wheels) to reconstruct track geometry, in particular vertical defects such as bumps or hollows, known as leveling defects and the left-hand side (defect d2 in the figure below).<\/p>\n","innerContent":["\n

    The idea is to analyze the accelerations measured at the axleboxes (the parts that connect the wheels) to reconstruct track geometry, in particular vertical defects such as bumps or hollows, known as leveling defects and the left-hand side (defect d2 in the figure below).<\/p>\n"],"rendered":"\n

    The idea is to analyze the accelerations measured at the axleboxes (the parts that connect the wheels) to reconstruct track geometry, in particular vertical defects such as bumps or hollows, known as leveling defects and the left-hand side (defect d2 in the figure below).<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"The conventional method relies on double integration of acceleration signals. However, this approach comprises several sources of error, including complex axlebox movements (transfers, rotations, inclinations), the influence of train dynamics, variations in ballast and sleeper rigidity in different zones, and imperfect orientation of accelerometers. These factors affect the accuracy of measurements.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    The conventional method relies on double integration of acceleration signals. However, this approach comprises several sources of error, including complex axlebox movements (transfers, rotations, inclinations), the influence of train dynamics, variations in ballast and sleeper rigidity in different zones, and imperfect orientation of accelerometers. These factors affect the accuracy of measurements.<\/p>\n","innerContent":["\n

    The conventional method relies on double integration of acceleration signals. However, this approach comprises several sources of error, including complex axlebox movements (transfers, rotations, inclinations), the influence of train dynamics, variations in ballast and sleeper rigidity in different zones, and imperfect orientation of accelerometers. These factors affect the accuracy of measurements.<\/p>\n"],"rendered":"\n

    The conventional method relies on double integration of acceleration signals. However, this approach comprises several sources of error, including complex axlebox movements (transfers, rotations, inclinations), the influence of train dynamics, variations in ballast and sleeper rigidity in different zones, and imperfect orientation of accelerometers. These factors affect the accuracy of measurements.<\/p>\n"},{"blockName":"core\/image","attrs":{"id":8262,"width":"492px","height":"auto","sizeSlug":"full","linkDestination":"none","align":"center","blob":"","url":"https:\/\/ingenius.ecoledesponts.fr\/wp-content\/uploads\/2025\/05\/defauts-de-voie.jpg","alt":"","caption":"The four types of track defects. Credit\u00a0: M. Chihaoui","lightbox":[],"title":"","href":"","rel":"","linkClass":"","aspectRatio":"","scale":"","linkTarget":"","lock":[],"metadata":[],"className":"wp-block-image aligncenter size-full is-resized","style":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    \"\"
    The four types of track defects. Credit : M. Chihaoui<\/figcaption><\/figure>\n","innerContent":["\n
    \"\"
    The four types of track defects. Credit : M. Chihaoui<\/figcaption><\/figure>\n"],"rendered":"\n
    \"\"
    The four types of track defects. Credit : M. Chihaoui<\/figcaption><\/figure>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    <\/p>\n","innerContent":["\n

    <\/p>\n"],"rendered":"\n

    <\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"To overcome these difficulties, the researchers developed an improved reconstruction method. This takes into account more elements that distort the measurements, such as the effects of gravity and centrifugal forces, and adjusts the data according to the actual orientation of the sensors. It draws in particular on differences in acceleration between the left-hand and right-hand sensors to better estimate axle inclination. Tested on real data, this new method produces significantly more reliable results, by reducing the discrepancies between estimates and actual track geometry. ","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    To overcome these difficulties, the researchers developed an improved reconstruction method. This takes into account more elements that distort the measurements, such as the effects of gravity and centrifugal forces, and adjusts the data according to the actual orientation of the sensors. It draws in particular on differences in acceleration between the left-hand and right-hand sensors to better estimate axle inclination. Tested on real data, this new method produces significantly more reliable results, by reducing the discrepancies between estimates and actual track geometry. <\/p>\n","innerContent":["\n

    To overcome these difficulties, the researchers developed an improved reconstruction method. This takes into account more elements that distort the measurements, such as the effects of gravity and centrifugal forces, and adjusts the data according to the actual orientation of the sensors. It draws in particular on differences in acceleration between the left-hand and right-hand sensors to better estimate axle inclination. Tested on real data, this new method produces significantly more reliable results, by reducing the discrepancies between estimates and actual track geometry. <\/p>\n"],"rendered":"\n

    To overcome these difficulties, the researchers developed an improved reconstruction method. This takes into account more elements that distort the measurements, such as the effects of gravity and centrifugal forces, and adjusts the data according to the actual orientation of the sensors. It draws in particular on differences in acceleration between the left-hand and right-hand sensors to better estimate axle inclination. Tested on real data, this new method produces significantly more reliable results, by reducing the discrepancies between estimates and actual track geometry. <\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"The study was then extended to a type of defect that is more difficult to detect: lateral defects, i.e. irregularities that deviate the track to the left or to the right (defect d3\u00a0and d4 in the figure above). For this purpose, a model was developed, taking into consideration the train body, the track layout and its irregularities. By inverting this model and analyzing the kinematics (movement) of the axle, it has been shown that lateral offset can be estimated from the axle's lateral position and swaying - the fact that it tilts slightly to one side. These two measures can be obtained using the accelerometer measurements, combined with knowledge of the track curvature.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    The study was then extended to a type of defect that is more difficult to detect: lateral defects, i.e. irregularities that deviate the track to the left or to the right (defect d3<\/sub> and d4<\/sub> in the figure above). For this purpose, a model was developed, taking into consideration the train body, the track layout and its irregularities. By inverting this model and analyzing the kinematics (movement) of the axle, it has been shown that lateral offset can be estimated from the axle's lateral position and swaying - the fact that it tilts slightly to one side. These two measures can be obtained using the accelerometer measurements, combined with knowledge of the track curvature.<\/p>\n","innerContent":["\n

    The study was then extended to a type of defect that is more difficult to detect: lateral defects, i.e. irregularities that deviate the track to the left or to the right (defect d3<\/sub> and d4<\/sub> in the figure above). For this purpose, a model was developed, taking into consideration the train body, the track layout and its irregularities. By inverting this model and analyzing the kinematics (movement) of the axle, it has been shown that lateral offset can be estimated from the axle's lateral position and swaying - the fact that it tilts slightly to one side. These two measures can be obtained using the accelerometer measurements, combined with knowledge of the track curvature.<\/p>\n"],"rendered":"\n

    The study was then extended to a type of defect that is more difficult to detect: lateral defects, i.e. irregularities that deviate the track to the left or to the right (defect d3<\/sub> and d4<\/sub> in the figure above). For this purpose, a model was developed, taking into consideration the train body, the track layout and its irregularities. By inverting this model and analyzing the kinematics (movement) of the axle, it has been shown that lateral offset can be estimated from the axle's lateral position and swaying - the fact that it tilts slightly to one side. These two measures can be obtained using the accelerometer measurements, combined with knowledge of the track curvature.<\/p>\n"},{"blockName":"core\/heading","attrs":{"style":{"elements":{"link":{"color":{"text":"var:preset|color|red"}}}},"textColor":"red","textAlign":"","content":"Towards smarter, more sustainable rail maintenance","level":2,"levelOptions":[],"placeholder":"","lock":[],"metadata":[],"align":"","className":"wp-block-heading has-red-color has-text-color has-link-color","backgroundColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Towards smarter, more sustainable rail maintenance<\/h2>\n","innerContent":["\n

    Towards smarter, more sustainable rail maintenance<\/h2>\n"],"rendered":"\n

    Towards smarter, more sustainable rail maintenance<\/h2>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"The work carried out at the Navier laboratory illustrates the wealth of possible approaches, combining refined modeling, experimentation and technological development. Whether detecting invisible damage to concrete blocks on slab tracks using modal analysis and robotization, or accurately reconstructing geometric defects on ballasted tracks using on-board sensors, this research is paving the way for more predictive, more efficient and less intrusive maintenance techniques. It is helping to modernize inspection practices, while reducing costs and the impact on operations.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    The work carried out at the Navier laboratory illustrates the wealth of possible approaches, combining refined modeling, experimentation and technological development. Whether detecting invisible damage to concrete blocks on slab tracks using modal analysis and robotization, or accurately reconstructing geometric defects on ballasted tracks using on-board sensors, this research is paving the way for more predictive, more efficient and less intrusive maintenance techniques. It is helping to modernize inspection practices, while reducing costs and the impact on operations.<\/strong><\/p>\n","innerContent":["\n

    The work carried out at the Navier laboratory illustrates the wealth of possible approaches, combining refined modeling, experimentation and technological development. Whether detecting invisible damage to concrete blocks on slab tracks using modal analysis and robotization, or accurately reconstructing geometric defects on ballasted tracks using on-board sensors, this research is paving the way for more predictive, more efficient and less intrusive maintenance techniques. It is helping to modernize inspection practices, while reducing costs and the impact on operations.<\/strong><\/p>\n"],"rendered":"\n

    The work carried out at the Navier laboratory illustrates the wealth of possible approaches, combining refined modeling, experimentation and technological development. Whether detecting invisible damage to concrete blocks on slab tracks using modal analysis and robotization, or accurately reconstructing geometric defects on ballasted tracks using on-board sensors, this research is paving the way for more predictive, more efficient and less intrusive maintenance techniques. It is helping to modernize inspection practices, while reducing costs and the impact on operations.<\/strong><\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    <\/p>\n","innerContent":["\n

    <\/p>\n"],"rendered":"\n

    <\/p>\n"},{"blockName":"core\/footnotes","attrs":{"lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","fontSize":"","fontFamily":"","borderColor":""},"innerBlocks":[],"innerHTML":"","innerContent":[],"rendered":""}],"seo":{"title":"Monitoring damage to railway tracks"},"media":{"img":"\"\"","src":"https:\/\/ingenius.ecoledesponts.fr\/wp-content\/uploads\/2025\/05\/Cobra_G.Foret_.jpg"},"url":"\/en\/articles\/monitoring-damage-to-railway-tracks\/","related":{"post":[],"author":[{"title":"Denis Duhamel","url":"\/en\/authors\/denis-duhamel\/","id":"8307","media":"\"\"","slug":"denis-duhamel"},{"title":"Gilles Foret","url":"\/en\/authors\/gilles-foret\/","id":"8308","media":"\"\"","slug":"gilles-foret"}],"subject":[{"title":"Cities, Urban planning & Construction","url":"\/en\/subjects\/cities-urban-planning-construction\/","id":"936","media":"\"\"","slug":"cities-urban-planning-construction"}],"category":[{"title":"Articles","url":"\/en\/articles\/category\/articles\/","id":"1716","media":"","slug":"articles","_related_post_type":""}],"folder":[{"title":"Adapting Rail Transport in France: Flow, Stations, and Resilience","url":"\/en\/folders\/adapting-rail-transport-in-france-flow-stations-and-resilience\/","id":"8304","media":"\"S'inspirant","slug":"adapting-rail-transport-in-france-flow-stations-and-resilience"}]},"translated":"https:\/\/ingenius.ecoledesponts.fr\/articles\/surveillance-de-lendommagement-des-voies-ferrees\/","icon":"icon-article","duration":"6","custom_excerpt":"Monitoring the condition of railway tracks is vital for safety and the smooth flow of traffic. Wear and tear caused by the weather, frequent train traffic and vibrations can lead to deformation of the track ballast, as well as damage to sleepers and connecting elements. Without prompt maintenance, this damage can lead to serious accidents, slow-downs and interrupted services.","duration_type":"","_links":{"self":[{"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/posts\/8287","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/comments?post=8287"}],"version-history":[{"count":3,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/posts\/8287\/revisions"}],"predecessor-version":[{"id":8313,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/posts\/8287\/revisions\/8313"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/media\/8260"}],"wp:attachment":[{"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/media?parent=8287"}],"wp:term":[{"taxonomy":"article-types","embeddable":true,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/article-types?post=8287"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}