A Numerical Study of the Behavior of Sand-Crumb Rubber Mixture-Filled Trench for Active Vibration Isolation

Ground-borne vibrations produced by various human activities and natural events frequently have undesirable impacts on human life and the environment. To achieve healthy living conditions, it is necessary to isolate these ground vibrations using appropriate methods. The present study aimed to assess the efficacy of open trench (OT) and sand-crumb rubber mixture-filled trench (SCRT) barriers as an active vibration isolation system through numerical analysis using a three-dimensional (3D) FEM model. The numerical analysis simulates an oscillating rectangular foundation surrounded by a semicircular trench barrier. The sand-crumb rubber (SCR) mixture was considered an infill material in the trench. The efficiency of the wave barrier was evaluated in terms of the average amplitude reduction factor (AArf). The impact of various influencing factors such as width and depth of the trench, excitation frequency, distance of pickup points from the source, and distance of the trench from the source on AArf was also aimed to be investigated. The major factor influencing the isolation effectiveness of the OT and SCRT was found to be the depth of the trench. The study concludes that although the OT is more effective at reducing vibrations, an SCRT with sufficient depth provides comparable isolation to an OT. The open trench showed an average efficiency ranging from 80% to 85%, whereas the sand-crumb rubber mixture-filled trench had an average efficiency ranging from 65% to 75% for depths equal to or greater than Rayleigh wavelength.