An integrated approach for the dynamic performance estimation of an embedded rail track system

Vibrations and structure borne noise due to train transit in underground railways is still one of the major technical issues for both network operators and companies involved in track engineering and construction. Various kind of ballastless track systems are often installed in tunnels of urban mass transit systems to reduce vibrations and structure borne noise [1]. This paper deals with an innovative embedded-rail track system which is designed for combining the advantages of improved vibration attenuation with those of reduced maintenance costs. An integrated approach to support the system design is illustrated, which consists in 2D modelling, finite element analysis, lab tests and time-domain numerical simulation of train-track dynamic interaction. In particular, starting from the results of smallscale lab tests for system dynamic characterization, a multi-axial rheologic model of the embedded rail has been identified. This model has then been implemented into the simulation code for train-track dynamic interaction, thus allowing to accurately estimate both the quasi-static and dynamic performances of the embedded rail track system. Experimental tests on a test section of the considered innovative embedded-rail track system have been carried out showing that the developed integrated approach was able to correctly predict both the static and dynamic behavior of the system during train transit in terms of gauge widening and vertical rail deflection.