Finite Element Modeling of the Dynamic Response of Critical Zones in a Ballasted Railway Track

The critical zones are the discontinuities along a railway line that highly susceptible to differential settlement, due an abrupt variation in support conditions over short span. Consequently, these require frequent maintenance ensure adequate levels of passenger safety and comfort. A proper understanding behavior tracks at is imperative enhance their performance reduce frequency costly operations. This paper investigates dynamic zone bridge-open track transition under moving train loads using two-dimensional finite element approach. influence different subgrade types on studied. effectiveness geogrids, wedge-shaped engineered backfill with reduced sleeper spacing improving evaluated. numerical model successfully validated against field data reported literature. results indicate soil significantly influences response softer side zone. difference vertical displacement between stiffer decreases increase strength stiffness soil. layer also contribution granular layers (ballast subballast) overall response. As becomes stronger, increases. mitigation techniques improve or may prove more effective for stiff than soft subgrade. Among all investigated, improved by gradually increasing stiffness.