Key Construction Technology of Track Slab in Turnout Zones on Passenger Dedicated Lines

Diverse types of ballastless track have been developed in turnout zones, of which the prefabricated slab track in turnout zones is characterized with simple and fast construction technology and thus can preferably achieve the structure requirements. Slab tracks can be put into use after the track components are installed completely. A high demand is raised to ensure the accuracy of construction because of the complicated structure and force bearing status. This paper mainly shows the structure features, construction technology process and construction methods. Meanwhile, the construction control standards and important matters needed attention are involved too. The prefabricated slab track system in turnout zones is mainly made of turnout components, prefabricated turnout slab, concrete base and so on, which has advantages of lower structural height, stable track geometry status and less maintenance. The transition from turnout zones to section of ballastless track lines can be achieved easily without extra components. Moreover, the turnout slabs are prefabricated indoor so that the structure strength and durability can be guaranteed. At the same time by using the prefabricated slabs, the installation accuracy is improved and the amount of concrete made in site is greatly reduced. The construction of slab track turnouts mainly include construction of frost retarding layer, leveling blanket and supporting layer, rough track laying, accurate adjustment of turnout slabs, and installation of turnouts. More attention should be paid to the construction accuracy and the ability of keeping track geometry in order to achieve the high transition regularity.