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.