Ground vibrations induced by traffic and industrial activities can adversely affect human comfort and nearby sensitive equipment. Wave barriers, particularly open trenches (OTs), are recognized as effective vibration isolation solutions; however, their practical implementation may be limited by the difficulties associated with maintaining a fully OT. While trench infilling and sand crumb rubber mixture (SCRM) materials have been investigated separately, a continuous, non-alternating, partially SCRM-filled trench configuration has not yet been systematically evaluated through detailed numerical analysis for single and multiple trench arrangements. PLAXIS 2D was used to compare open, fully SCRM-filled, and partially SCRM-filled trenches at filling ratios of 25%, 50% and 75%, with the lower portion filled and the upper portion, within the near-surface zone of highest Rayleigh wave energy concentration, left open. Although the OT provided the highest isolation efficiency, followed by the 25% filling configuration, the 50% SCRM-filled configuration (SCRMT) emerged as a more practical alternative, achieving a barrier efficiency close to that of the OT (70% versus 75%, under identical conditions) while reducing the required unsupported open-trench depth by half and diverting waste tire material from landfills. The influence of trench depth, width, source-to-trench distance, and multiple-trench arrangement on SCRMT performance was also examined.