High‐Speed Rail Track Design

Abstract

While the new generation of high speed rail (HSR) vehicles is generally accepted as an obvious necessity for HSR operations, the need for higher track standards for new HSR lines and high‐speed upgrades of conventional track is not as well accepted. Yet, the vehicles and the track are combined into one system which cannot function effectively with relatively simple track approaches valid for 200 km/h (124 mph) speeds. Continuous improvement to the rail mode has brought some first class foreign lines close to the condition needed for truly high‐speed operations. However, fundamental updates will be necessary in the areas of design theory, products, and construction practices in the domestic, mostly highaxle‐load, freight‐dominated railroad environment to duplicate the perfect safety record of existing HSR lines and to avoid unnecessary remedial costs. The new requirements include precision‐rolled heavy rail; fasteners providing constant elastic clamping force; laterally stable and vertically uniform support by concrete ties or slab track; and subgrade designed for special dynamic loading transfer into greater than usual depths. Proper high‐speed track design will facilitate tight track tolerances and minimize maintenance of track and vehicular equipment.