Next Generation Foundations for Special Trackwork – Phase I

This report reviews the dynamic load environment and failure modes of special trackwork frog foundations. Key measurements taken under a 39,000-pound wheel load traffic at the Facility for Accelerated Service Testing were used to develop and calibrate a vehicle-track model. Parametric studies show the following: (1) for new crossings without any track differential settlement, optimal foundation stiffness and damping could lower the current wheel-rail (W-R) impact by 30 percent, (2) for worn crossings, W-R impact increases significantly with foundation stiffness and damping; and (3) W-R impact increases with track differential settlement. On the basis of the modeling results, this report proposes preliminary design and maintenance guidelines for improving crossing performances.