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

it starts to use the slab track on the German High-speed network, as shown in Sugrue (2013).

France set its first world record in 1955 reaching a speed of 331 km/h, as described by Givoni
(2007). However, it will be necessary to wait until 1981 to witness the inauguration of the TGV's
first High-speed line between Paris and Lyon, reaching a speed of 270 km/h on a ballasted track,
as shown in Kim (2000).
On the other hand, in 1992, the first High-speed line between Madrid and Seville was inaugurated
in Spain, with a maximum speed of 300 km/h over a ballasted track, as described by Gutierrez
Puebla (2004). This line reduced the travel time by train between Madrid and Ciudad Real from
160 minutes to 50, generating an increase in the mobility between the two cities from 310,161
passengers in 1990 to 740,972 in 2000, as shown in Ureña et al. (2005).
Both the Spanish High-speed model and the French model have developed their entire network
under the typology of ballasted track for a maximum operating speed of 300 km/h and 320
km/h, respectively, as shown in UIC (2017).

2.2 Multicriteria assessment to choose the superstructure typology

As can be seen in the previous paragraphs, there are very different philosophies depending
on each country, with respect to the type of superstructure to be used in High-speed lines.
Therefore, this topic has been widely discussed by authors such as Esveld (1999) and Esveld
et al. (2003), who explained the advantages of the use of the slab track against the ballasted
track. Koriath et al. (2003) established the main criteria for the objective selection of the
typology of the railway superstructure on the German rail network. Then, in 2008 the studies
carried out by CEDEX (2008) showed the medium and long-term behavior of both superstructure
typologies.
Ren et al. (2009) performed an economic analysis of the life cycle of a ballasted
track and compared it with a slab track. Kollo et al. (2015) developed also a detailed
technical-economic comparison between both types of superstructure. Finally, Giunta
et al. (2017) made a comparison between the use of slab track or ballasted track in
High-speed lines from the point of view of the overall study of the life cycle costs of
both solutions.

2.3 Limits of implementation of a ballasted track in a High-speed line

On the other hand, some authors have highlighted the main problems that arise with the
use of ballasted track with High-speed traffic. López Pita (2001) analyzed the acceleration
experienced by the ballast deterioration when subjected to High-speed traffic. Riessberger
(2006) developed a study to defend the use in High-speed lines of the ballasted track but
applying certain improvements or modifications to the traditional design.
Al-Shaer et al. (2008) developed a study on the dynamic behavior of the ballasted track and
its settlements, in High-speed lines, by using a physical scale model. Nguyen et al. (2011)
made a model to study the mechanisms of deterioration of High-speed lines with ballasted
track.
Finally, Giannakos et al. (2012) outlines the main requirements to be met by ballast for its use
in High-speed lines.
However, slab track systems also have important disadvantages such as the impossibility of
great geometrical corrections after track construction, the very tight limitation regarding to
earthwork settlements and the higher installation costs, as shown in Blanco-Lorenzo et al.
(2011).

International Congress on High-speed Rail: Technologies and Long Term Impacts - Ciudad Real (Spain) - 25th anniversary Madrid-Sevilla corridor 221