2.5D Modeling of Metabarriers under Moving Loads for Ground-Borne Vibration Mitigation in Layered Soils

Designing mitigation measures for ground-borne vibrations from traffic sources in urban areas, whether in tunnels or at the surface, requires advanced and efficient modeling approaches. This contribution presents a 2.5D modeling approach for analyzing a metabarrier embedded in the soil to mitigate vibrations generated by moving loads. The soil is modeled using the Integral Transform Method (ITM), which provides a semi-analytical solution for a cylindrical cavity in an elastic half-space and inherently satisfies the radiation condition [1]. The ITM is extended to account for multiple cylindrical boundary surfaces in a layered half-space. Twofold Fourier-transformed finite elements are coupled at these surfaces, enabling the inclusion of components with arbitrary geometry and material composition. This allows for the modeling of an underground railway tunnel or a surface track, as well as the metabarrier embedded in the soil. The source is modeled as a harmonic moving load, incorporated as a wavenumber-dependent frequency shift in the wavenumber–frequency domain. The resulting hybrid framework efficiently captures the structure–soil–structure interaction (SSSI). The proposed methodology is demonstrated through an exemplary study of a metabarrier embedded in a layered half-space and subjected to an incident wave field generated by a harmonic moving load. The metabarrier consists of an array of subsurface resonators that act as a seismic metamaterial, reducing vibrations through local resonance. Amplitude reduction factors are evaluated to quantify the performance in homogeneous and layered soil configurations.