The ELeMEnt project proposes a research framework to devise, design, fabricate, and test an innovative Thick Resonant Wave Barrier (TRWB) to mitigate railway ground vibrations. The proposed device aims to overcome some limitations of the available railway vibration mitigation technologies, namely trenches and pile barriers. By exploiting the locally resonant metamaterial concept, the proposed approach allows for designing resonant wave barriers with significant attenuation capabilities and practical engineering dimensions. The main research objectives of the project include (i) analytical design of TRWB guided by dispersion laws and exploiting Multiple Scattering theory, (ii) numerical design and optimization of TRWB by using the wave finite element method, and (iii) prototyping and testing of TRWB on the field. The development of the ELeMEnt project demands an interdisciplinary approach integrating civil engineering, applied physics, and material engineering. In-depth knowledge of advanced analytical methods, numerical approaches, fabrication, and measurement techniques is planned to be acquired via a high-level training-through-research framework. The outcomes of the ELeMEnt project will provide major advancements beyond current state-of-the-art within the metamaterial and civil engineering communities from a fundamental and applied perspective. Attending training courses and seminars, publishing research results in top international journals, and obtaining new transversal skills will reinforce the career of the research fellow. Overall, the ELeMEnt project aims to contribute to the "infrastructures for sustainable mobility" mission of PNRR by safeguarding railway infrastructures against train-induced vibrations.