چكيده به لاتين
Abstract
The importance of comfort index, noise reduction, diminishing deteriorations of track, and lessening track maintenance costs in CWR tracks are advantages that encourage railway engineers to bring about by removing rail gaps in joints and by welding rails. However, high lateral forces and buckling possibility and lateral movements in small radius curves are major obstacles of removing gaps that require special measures to improvement performance of track.
In one hand, in the ballast layer, ballast corrosion resulting from the traffic of the rolling stock during the period of operation and on the other hand, the penetration of the fine grains from the bed, surface spillage, wind, etc, changes the grading in the ballast. With the change in the grading, the study of behavior of the ballast in the face of large lateral loads caused by temperature and instability of wagons, is inevitable.
In this research a novel investigation on behavior of the ballast with sand and clay contamination in the technical literature of lateral resistance and ballast fouling has been performed. Choosing clay fouling as fine grain, sand as coarse grain and contaminating the ballast layer up to 5%, 10%, 15% and 20% with these fouling materials, lead us to study the effect of percentage and type of the fouling materials on lateral resistance. Results of the single tie push test (STPT) demonstrated that an increase in the amount of fouling of the samples, boosts the lateral resistance. Moreover, effect of coarse fouling materials (sand) is more than fines (clay).
Keywords: Lateral resistance, Fouling index, Ballast contamination, Clay, Sand, Single Tie Push Test, STPT.
