A METHOD FOR UPGRADING THE PERFORMANCE AT TRACK TRANSITIONS FOR HIGH-SPEED SERVICE

High-speed trains in the speed range of 100 to 160 mph require tracks of nearly perfect geometry and mechanical uniformity, when subjected to moving wheel loads. Therefore, this report briefly describes the remedies being used by various railroads to create smoothed transition regions. Some of the associated shortcomings are pointed out. Then, the method of matched pads, as presented by Kerr and Moroney (1993), is described. The aim of this method is to eliminate the need for transition sections by "softening" the tracks on the bridge, so that dynamic loads caused by the moving trains are greatly reduced. As part of this effort, matched pads were developed, produced, and installed on a number of open-deck bridges. Field measurements revealed that the improvements caused by the installation of the matched pads and the associated treatment of the tracks near the abutments may be very significant. The obtained results suggest that the use of matched pads may be an effective and economical way to eliminate, or greatly reduce, the effect of track transitions and that it could be useful for adjusting existing railway tracks for high-speed train travel.