Longitudinal Restrain of the Newly Developed Floating Fastener

Railway fastening systems are a crucial component of railway tracks, playing a significant role in ensuring the stability of the track and preventing gauge widening and rolling. The ability to resist longitudinal loads along the rail is among the most important qualities a good fastening system should have. This value is usually measured as a fastening system’s longitudinal restraint and has stipulated procedures to perform the test, in accordance with the international standard or the European standard requirements. Longitudinal loads mainly occur due to creep, rail thermal expansion and contraction, acceleration and deceleration of the train. In view of the fact that the modern tracks experiences large longitudinal forces, the fastening systems should provide adequate restraint force to withstand these types of forces. In this paper, we will study the longitudinal restraint of the recently developed Jiuzhou floating fastener. The test is conducted in accordance with the procedure provided by the European railway fastening system testing standard. The fastener was fastened to a concrete block, and a hydraulic actuator of 25kN was used to apply a push to the rail fixed to the concrete block by the floating fastener. A displacement accelerometer was placed on the end of the rail at the centroid region of the rail to ensure that accurate and reliable results were collected. A push force was applied on the rail until the rail slipped from the assembly while simultaneously recording the rail displacement in relative to the support using the displacement sensors. The load is then unloaded to zero. This procedure was repeated for four times without any adjustment to the set-up, the first data was ignored, and the other three data were collected and averaged to obtain the final longitudinal restraint of the fastening assembly. The floating fastening assembly longitudinal restraint was calculated to be 14.04kN, which satisfactorily meets the standard requirement for longitudinal restraint value which should not be less than 9kN for fasteners intended for high-speed railways.