Rapid Estimation of Fouled Railroad Ballast Mechanical Properties

Abstract

Ballast fouling and ballast deterioration are significant maintenance concerns. Ballast fouling occurs because of the wearing of the ballast against the tie and other ballast, along with the intrusion of fines from the subgrade and deposition of coal dust or soil particles from the surface. In this study, the assessment of mechanical properties of fouled ballast using available geotechnical tests is discussed. These mechanical properties include subgrade reaction modulus from static plate loading tests, dynamic deformation modulus from light weight deflectometer (LWD) tests, and California bearing ratio (CBR) from dynamic cone penetrometer (DCP) tests. The test results show similar trends for these mechanical properties, which were determined by varying the fouling amount as well as the moisture content. The mechanical properties first increased with the moisture content up to a certain value and then decreased rapidly after a peak value. This article also discusses the correlations between these mechanical properties developed from the tests.

Assessment technologies of rail systems’ structural adequacy — A review from mechanical engineering perspectives

“…Important maintenance concerns are related to ballast fouling and ballast deterioration. 74 Ballast fouling is connected to ballast stiffness. Fouling happens as a result of 72 the ballast's wear against the bond and other ballast, as well as the disruption of subgrade losses and the removal of soil particles or coal dust from the surface.…”

Degraded Ballast Stiffness Characterization Using Bender Element Field Sensor and PANDA® Penetrometer

“…Despite the importance of the stiffness characterization of ballast, no proper tool to quantify the ballast stiffness has been developed because of the challenging opengraded and uniform-sized nature of clean ballast. Dynamic cone penetration (DCP) and lightweight deflectometer (LWD) tests can be used for estimating ballast stiffness in the field, which often requires the use of empirical correlations with a limitation in measuring depth (11)(12)(13). In addition, seismic survey methods using spectral analyses of surface waves have been adopted to estimate the ballast stiffness (14)(15)(16).…”