Exploring the Impact of Geosynthetic Reinforcement on Ballast Deformation in Experimental Studies

The ballast layer in railway tracks plays a critical role in distributing wheel loads and maintaining track alignment. However, repeated loading can lead to ballast degradation and deformation, impacting track performance. Geogrids have emerged as a popular solution for stabilizing ballast, but their effectiveness depends on the ballast-geogrid interaction. This study aims to identify the optimal geogrid for stabilizing ballast and investigate its impact on deformation and degradation under typical loading conditions.Experimental tests were conducted using a large-scale direct shear apparatus to study ballast-geogrid interface behavior and determine the effect of geogrid aperture size on interface shear strength. A Process Simulation Test (PST) apparatus was designed to simulate realistic ballast behavior, and model track tests were performed to evaluate the influence of geogrid on permanent deformation and degradation. Additionally, the study explored the use of optical fiber Bragg grating (FBG) sensors for monitoring ballast deformations. (۱)Results showed that geogrid aperture size significantly influenced interface shear strength, with an optimal aperture size of ۱.۲۰D۵۰. The study proposed the Feeble Interlock Zone, Optimum Interlock Zone, and Diminishing Interlock Zone based on A/D۵۰ ratios. The PST apparatus modification allowed for a realistic simulation of the non-uniform lateral spreading of ballast under cyclic loading. (۲)Model track tests demonstrated that geogrids effectively reduced lateral strains in ballast, minimizing settlement and particle breakage. The study introduced the lateral spread reduction index (LSRI) and geogrid influence zone (GIZ) to assess geogrid-reinforced ballast performance. The LSRI significantly impacted ballast settlement and breakage, with geogrid placement location playing a crucial role. (۳,۴)Overall, this study provides in-depth insights into ballast-geogrid interactions and their effects on ballast behavior, with implications for rail track design and maintenance cost reduction in the railway industry. (۵)

کلیدواژه ها:

geogrid ، ballast ، word ، railways ، transportation