Identifying frost-susceptible areas on Finnish railways using the ground penetrating radar technique

Abstract

In Finland, the railway is a vital transportation system. A large quantity of raw materials, goods and passengers are transported on mixed traffic tracks. Due to freeze-thaw cycles, differential frost heave can affect the track performance and results in speed restrictions. The maintenance of winter-related problems on heavy haul railway lines is expensive and causes difficulties for the flow of rail traffic. In order to make maintenance cost-effective and sustainable it is essential to identify the problem areas and determine their causes. During the last decade the ground penetrating radar (GPR) technique has proven to be an effective and non-destructive method to measure railway structures and various material properties. This paper presents and discusses the key results obtained in a research project that studied the potential of the GPR method to locate track sections on Finnish railways experiencing frost problems and produce input data for preventative maintenance planning for areas at risk of developing differential frost heave. The GPR data, digital video and GPS coordinates, collected from the railway sections were combined with reference data and railway databases using the Railway Doctor software. This integrated data was then interpreted and analysed using multiple parameters specifically selected for the purpose of identifying the frost-susceptible sub-ballast structures and subgrade soils and defining the root cause of frost problems using the GPR frequency analysis techniques.

Analysis of the Dynamic Wheel Loads in Railway Transition Zones Considering the Moisture Condition of the Ballast and Subballast

“…Dielectric Constant Velocity (m/s) In the post-process stage, measurement results are transformed into frequency-domain data and are parameterized by means of a sliding calculation window in depth and longitudinal directions using the windowed Fourier transform (WFT) [39]. Results are then visualised as a colour-coded image, wherein the strong reflections (blue) indicate high moisture susceptibility and weak reflections (red) low.…”

“…The processing, visualization, interpretation, and analysis of the GPR data are performed using the Rail Doctor software (version 3.2), developed by Roadscanners Oy, Rovaniemi, Finland, 2017. The measurement system has been calibrated against sample analysis [38] and pit tests [39]. A screenshot from the recorded video is shown in Figure 4a, wherein a transition zone consisting of embankment and a bridge can be found.…”

“…GPR data consists of changes in reflection amplitude, changes in the arrival time of specific reflections, and signal attenuation [32,38]. The method provides a continuous profile of the thickness and properties of railway structures, which can be used to analyse the quality of track substructures, such as the moisture susceptibility of ballast and subballast, fouling of ballast, layer deformation, and mud pumping [39][40][41].…”

Moddeling of Negative Ambient Air Temperature Effect to Frost Depth of Lithuania Railroads Construction

“…Geležinkelio kelio konstrukcija (GKK), veikiama traukinių eismo apkrovų, klimato ir aplinkos oro veiksnių, deformuojasi, dėl to kinta kelio kokybės indeksas (KKI) (Bai et al 2015;Bezgin 2015;Silvast et al 2013).…”

Current and future role of instrumentation and monitoring in the performance of transport infrastructure slopes

“…Dynamic ground-based sensing systems, such as terrestrial LiDAR (Lato et al 2009(Lato et al , 2012Marjanovic et al 2013;Fan et al 2014), radar inferferometry Caduff et al 2014), ground penetrating radar (GPR; Donohue et al 2011Donohue et al , 2013Silvast et al 2013) and capacitive resistivity imaging (CRI; Kuras et al 2007) can obtain greater spatial and subsurface information, but are limited in terms of temporal resolution by the need for manual data collection, and therefore can be expensive when frequent (i.e. high temporal resolution) monitoring is required.…”