Results of tests of ballastless track designs on the Test Loop of JSC "VNIIZhT"
In December 2016 at the Test Loop of JSC “VNI-IZhT” comparative testing of four types of ballastless track designs (BVSP) - LVT (RZDstroy, Russia), FFB (MaxBögl, Germany), NBT (Alstom, France), EBS (Tines, Poland) - have been completed. The passed tonnage for the pilot section of the four structures was 600 million tonnes gross. The article analyzes the intensity of settlement of the ballastless track and in transitional sections under the train load. Conducted tests of four types of ballastless track designs LVT (RZhDstroy, Russia), FFB (MaxBögl, Germany), NBT (Alstom, France), EBS (Tines, Poland) and earlier tests of the Rheda (RailOne, Germany) design showed that for the ballastless track on the subgrade, the most critical are not the stresses in the structural elements, but the values of the vertical settlements. In the places of maximum values of the settlement of the upper bearing concrete (reinforced concrete) slab, the underlying layer of the hydraulically linked bearing layer of lean concrete is subsequently destroyed. Tests on the Test Loop of the train with an axial load of 23.5 tons showed that the BVSP design can be used for freight traffic. It is impractical to arrange ballastless track on one of the track of a two-track section. It is necessary to exclude the ingress of water between the bearing concrete slab and the hydraulically linked bearing layer (HLBL). The significant risks are that the ballastless track is more demanding for maintain the construction technology, the composition of the concrete mixes and the quality of the substrate preparation, as evidenced by splashes from the concrete bearing slabs. The probability of a malfunction on the ballastless track is much smaller, but the risk of a sharp increase in the costs of its elimination is much higher. Tests made it possible to confirm the working capacity of the ballastless railway track for the conditions of the Russian railways, to reveal the features of the current maintenance of each design and to give recommendations on its improvement. The tests carried out at JSC “VNIIZhT” test site showed that the ballastless track can be used not only for express and high-speed traffic, but also for combined and freight traffic.