Page 225 - 360.revista de Alta Velocidad - Nº 5

New design concepts for High-speed lines and the limits of the ballasted track

Figure 1. Historical evolution of ballasted track vs. slab track

From the results shown in figure 1 it is observed a significant increase in the use of the slab track
in High-speed lines during the last 5 years. This increase is mainly due to the fast expansion of
High Speed lines in China, which is using slab track in the main lines of its Highspeed network
and has developed more than 4,000 km during the last years. The use of the slab track is, among
other reasons, due to the high design speed that has been set in values between 350 to 380
km/h for some of the main lines. This is the case of the Beijing - Wuhan line with more than
1,200 km of slab track designed for a maximum speed of 380 km/h, the case of the Beijing -
Schanghai line with 1,318 km of slab track, also, for a maximum speed of 380 km/h or, the case
of the lines between Changsa - Hangzhou with 840 km and Heifei - Fuzhou with 810 km of slab
track respectively, both designed for maximum speeds in the range of 350 km/h.
Secondly, this growth in the installation of ballastless track includes countries that have
traditionally used it, such as Germany or Japan, which continue to expand their already
consolidated High-speed networks. In the case of Germany, the construction of the Leipzig /
Halle - Erfurt line, in which more than 123 km of slab track was installed for a speed of 300 km/h
and, in the case of Japan, construction of the Nagano - Kanazawa line, with the installation of
228 km of ballastless track for a maximum speed of 260 km/h.

3.3 Spanish High-speed model

By contrast, Spain and France continue to have the ballasted track as the base of their
Highspeed network, using the slab track in specific cases, such as long tunnels. In Spain, this
philosophy is motivated by the abrupt orography that presents the Spanish territory that forces
the construction of embankments with a height higher than the 10 meters.
The settlement caused by rail traffic is completed over the course of a few months, accounting
for approximately 0.1% of the embankment height, as estimated by Pérez-Romero et al. (2016).
Hence, the requirements to build slab track generally set the maximum embankment height
around 10 meters, as shown in DB Netze AG (2014), in order to control the postconstructive
settlement because the ballastless track allows only a maximum settlement in the range of 30
to 50 mm.

International Congress on High-speed Rail: Technologies and Long Term Impacts - Ciudad Real (Spain) - 25th anniversary Madrid-Sevilla corridor 223