A lattice model for transition zones in ballasted railway tracks

Abstract The procedure presented in this work aims at providing a framework for studying settlement of ballast zones with stiffness variation the railway track support. proposed results from expanding an existing infinite periodic model to account variations foundation. Ballast is simulated via linear lattice, whose dynamic response differs that continuum. expanded composed three regions: left region, which semi-infinite and periodic; mid-region, finite length where properties foundation can change; right also differ those region. equations motion mid-region are written directly time domain, rail being described by elements. On other hand, regions treated semi-analytically frequency afterwards their responses converted resulting convolution integrals prescribed boundaries simulate non-reflective boundaries. final only contains degrees freedom corresponding (which be as short region present), leads faster calculations than if were placed further away dissipate undesired reflections. method cast all elements assumed behave linearly. In future, will incorporate non-linear behaviour ballast. validated means simple examples, applied real scenario culvert crosses track. As presented, used study dynamics transitions zones, mitigation measures, infer about indicators like force transmitted energy dissipated, might useful assess development