Railway track and ground vibrations are considered, with anemphasis on methods of mitigation ("countermeasures"), forapplication to wayside disturbance problems. Original field measurements from two sites in Sweden, aswell as borrowed measurements from Norway, provide vibrationresults at many points on the track, on and underneath theground surface, for a variety of trains, both with and withoutcountermeasures in-place. Infinite periodic system theory is the basis of track-onlyand track-ground interaction models presented. The repeatingelement includes the sleeper, pad-fastener, rail, and either alocally-reacting ballast or a continuous ballast-soilwaveguide. The track-only model is even refined for nonlinearand high-frequency cases. The models are suitable for studyingcountermeasures in the track, or in the foundation(soil-stabilization). This latter countermeasure is shown to beeffective at low frequencies (of geotechnical interest), butsometimes counterproductive at audible frequencies (disturbanceproblems). An analytical model for hard seismic screens is alsopresented, to complement the treatment of ground vibrationcountermeasures; this is based on physical approximations whichare favored by "high" (i.e, audible)frequencies and softsoils. Notably, experimentally observed resonant behavior isexplained. <b>Keywords:</b>ground vibration, vibration screen, trackvibration, railway vibration

<p>Railway track and ground vibrations are considered, with anemphasis on methods of mitigation ("countermeasures"), forapplication to wayside disturbance problems.</p><p>Original field measurements from two sites in Sweden, aswell as borrowed measurements from Norway, provide vibrationresults at many points on the track, on and underneath theground surface, for a variety of trains, both with and withoutcountermeasures in-place.</p><p>Infinite periodic system theory is the basis of track-onlyand track-ground interaction models presented. The repeatingelement includes the sleeper, pad-fastener, rail, and either alocally-reacting ballast or a continuous ballast-soilwaveguide. The track-only model is even refined for nonlinearand high-frequency cases. The models are suitable for studyingcountermeasures in the track, or in the foundation(soil-stabilization). This latter countermeasure is shown to beeffective at low frequencies (of geotechnical interest), butsometimes counterproductive at audible frequencies (disturbanceproblems).</p><p>An analytical model for hard seismic screens is alsopresented, to complement the treatment of ground vibrationcountermeasures; this is based on physical approximations whichare favored by "high" (i.e, audible)frequencies and softsoils. Notably, experimentally observed resonant behavior isexplained.</p><p><b>Keywords:</b>ground vibration, vibration screen, trackvibration, railway vibration</p>

Ground-borne vibrations from railway systems not only pose threats to structural integrity of nearby buildings and cause annoyance on people but also contribute into environmental noise levels. It is of utmost importance to predict these vibrations at the design stage of such systems. This thesis attempts to reach this goal through finite elements analysis. Commercial software is used to develop a finite element model of an existing railway system. The model is based on the work of Forrest and Hunt [11]. It is also aimed to perform transient analysis in time domain to complement vibration information already obtained in frequency domain. The model is validated by checking maximum element size and comparing results with the infinite boundary condition case. Parametric studies are designed to investigate effects of soil type, railpad type and train speed on vibrations induced by underground train traffic. Results acquired through the finite element analysis are found to be in good harmony with the ones by existing numerical methods. The study demonstrates that the approach can be applied to predict ground-borne vibration from any configuration of railway systems.