Evaluation of Railway Ballast Permeability Using Machine Vision–Based Degradation Analysis

Abstract

Railway ballast degrades progressively as a result of accumulated traffic primarily through abrasion and particle breakage. Degraded ballast may cause reduced lateral and longitudinal stability, ineffective drainage, and excessive settlement of track structures, all of which would adversely affect the performance of ballasted track. Traditional methods of ballast degradation assessment involve time-consuming field sampling and laboratory sieve analysis; moreover, determining the level of track performance deterioration at which ballast maintenance is best considered still remains challenging. This paper investigates the permeability of railway ballast through laboratory testing and provides insight into its field drainage capacity under degraded condition using an innovative approach of field imaging. Constant head permeability tests were conducted on clean and degraded ballast samples which indicated nonlinear power-curve trends, especially for clean ballast, of unit flow amount with its hydraulic gradient. Imaging-based degradation analysis using machine vision technology was also performed on clean and degraded in-service ballast to correlate Fouling Index (FI) from laboratory sieving with Percent Degraded Segments (PDS) obtained from the recently developed image segmentation algorithm. Accordingly, a new Permeability Index (PI) is introduced in this paper to define ballast permeability in the form of a bilinear model developed from the machine vision–based ballast degradation analysis. Based on the findings of this study, a two-stage ballast cleaning process for determining the timeframe of ballasted track maintenance considering its drainage capacity is proposed.

Automated Segmentation and Morphological Analyses of Stockpile Aggregate Images using Deep Convolutional Neural Networks

“…In this connection, several research software and industrial applications have been developed. For example, Tutumluer et al ( 28 ) and Huang et al ( 29 ) applied watershed segmentation to characterize the degradation level in trench-view images of railway ballast by classifying the size distributions of image segments. Similarly, the commercial cross-platform software WipFrag, developed by Maerz et al ( 30 , 31 ), uses edge-based segmentation to partition rock fragments and estimate the particle size distribution in a stockpile image.…”

State-of-the-Art Review of Ground Penetrating Radar (GPR) Applications for Railway Ballast Inspection

“…The ballast layer is the main component of ballasted tracks, as shown in Figure 1 , and is mostly made of crushed rocks [ 5 , 6 ]. It has the function of supporting the sleeper evenly [ 7 , 8 ], transmitting loading uniformly to the substructure (subgrade, bridge, and tunnel) [ 9 , 10 ], resisting the sleeper movements [ 11 , 12 , 13 , 14 , 15 ], and providing sufficient drainage [ 16 , 17 , 18 ]. Currently, all kinds of railways (high-speed railways, heavy-haul railways, intercity, and metros) are rapidly developing worldwide, such as with the Belt and Road Initiative.…”

The Role of Chemical Composition of High-Manganese Cast Steels on Wear of Excavating Chain in Railway Shoulder Bed Ballast Cleaning Machine

“…In the case of railway system, the maintenance of the infrastructure is a complex subject, responsible not only for safety of passengers and goods, but also for efficiency of the whole logistic system [6,7]. This maintenance necessity is connected with every sub-part of the rail track: rail profiles, fastenings, sleepers and the ballast bed (Figure 1)-each having its own methodology of wear evaluation [7,8]. While keeping the rail track in a good shape is obvious to any observer, he or she may omit the importance of bedding conservation.…”

“…While keeping the rail track in a good shape is obvious to any observer, he or she may omit the importance of bedding conservation. methodology of wear evaluation [7,8]. While keeping the rail track in a good shape is ob-vious to any observer, he or she may omit the importance of bedding conservation.…”