Ground Improvement for a High Speed Railway Near Madrid (Spain)

For the extension of the lines of the Spanish high speed railway system, a new junction has recently been created to the south of Madrid (Spain). The objective of these works was to connect the lines Madrid-Valencia and Madrid-Seville in order to be able to go directly from Seville to Valencia. The work has been undertaken in the zone of Torrejón de Velasco (Madrid province). The ground of this zone is formed by: a) Anthropic fills. b) Very soft quaternary sediments, mainly clayey soils. c) Hard clay (near substratum). The height of the necessary embankments is variable (to from 2 m to 15 m). For this reason (and proximity to the high speed railway in operation) it has been necessary to design a major ground improvement under the embankments. This paper describes: a) The geotechnical properties of the soft soil (by means of field embankment tests and other field tests). b) The design of the ground improvement. c) The instrument field data obtained during the treatment.