Abstract
This paper aims to evaluate the effect of geogrid stabilization in clean and degraded railway ballast through small-strain stiffness measurement using Bender Element (BE) sensors. Laboratory tests on geogrid-stabilized crushed dolomite ballast with fouling indices (FI) from 0% to 40% were conducted, and the results were compared to unstabilized (control) conditions from the previous literature. The test results indicated that shear wave velocity (V-s) peaked at an FI of 20% for geogrid-stabilized ballast. Further, shear wave velocities were higher in geogrid-stabilized ballast in most cases, indicating that the stiffness was enhanced through geogrid stabilization. The small-strain shear modulus (G(max)) estimated through shear wave velocities was increased by 71.3% in clean ballast and 34.9% in heavily fouled ballast with geogrid stabilization. These findings highlight the potential of BE sensors for continuous and non-destructive monitoring in railway ballast.