Non-destructive Assessment and Health Monitoring of Railway Infrastructures

Abstract

A continuous increase of the demand for high-speed traffic, freight tonnage as well as of the train operating frequency is worsening the decay conditions of many railway infrastructures. This occurrence affects economy-related business as well as it contributes to raise maintenance cost. It is known that a failure of a railway track may result in tremendous economic losses, law liabilities, service interruptions and, eventually, fatalities. Parallel to this, requirements to maintain acceptable operational standards are very demanding. In addition to the above, a main issue nowadays in railway engineering is a general lack of funds to allow safety and comfort of the operations as well as a proper maintenance of the infrastructures. This is mostly the result of a traditional approach that, on average, tends to invest on high-priority cost, such as safety-related cost, compromising lower-priority cost (e.g., quality and comfort of the operations). A solution to correct this trend can be to move from a reactive to a proactive action planning approach in order to limit more effectively the likelihood of progressive track decay. Within this context, this paper reports a review on the use of traditional and non-destructive testing (NDT) methods for assessment and health monitoring of railway infrastructures. State-of-the-art research on a stand-alone use of NDT methods or a combination of them for specific maintenance tasks in railways is discussed.

Railway Ballast Monitoring by GPR: A Test Site Investigation

“…Necessarily, the monitoring procedures that allow for such a knowledge have to comply with costbenefits considerations. As a result, the quality of the monitoring in terms of dedicated funds is typically related to the rate of utilization of the inspected railway stretch [3]. In such a framework, increasingly efficient inspection techniques are required in order to lower the cost-to-benefit ratio, and allow for a wider assessment of the track-bed conditions over the entire network.…”

Railway Ballast Monitoring by GPR: A Test-Site Investigation

“…The superstructure is composed of the rails, the fastening system and the sleepers, whereas the substructure includes the granular layers that are laid upon the subgrade, i.e., the ballast and the sub-ballast. Specifically, ballast is referred to as a homogeneously graded hard-rock-derived material, usually composed of aggregates with a diameter size ranging between 3 and 6 cm [2,3].…”

“…Necessarily, the monitoring procedures that allow for such a knowledge have to comply with cost-benefits considerations. As a result, the quality of the monitoring in terms of dedicated funds is typically related to the rate of utilization of the inspected railway stretch [3]. In such a framework, increasingly efficient inspection techniques are required in order to lower the cost-to-benefit ratio, and allow for a wider assessment of the track-bed conditions over the entire network.…”

“…In view of this, advanced diagnostic trains equipped with additional systems for the direct assessment of the condition of the ballast have been introduced in the past few years [3]. Among the other equipment, Ground-Penetrating Radar (GPR) is one of the most employed for this type of service.…”

Guest Editorial: Recent Advances in Non-destructive Testing Methods

“…Validation field tests demonstrate a high level of accuracy in terms of estimating the asphalt concrete overlay thickness and density. A paper by Artagan et al (2020) reviews the use of conventional and NDT methods for the assessment and health monitoring of railway infrastructures. The review focuses on state-of-the-art research on stand-alone and the synergetic uses of NDT methods in quality control surveys and routine inspections, for infrastructure maintenance purposes.…”