Impact of diffraction on screening of dynamic compaction waves with barriers

As the dynamic compaction operation is accompanied by heavy weights and hard tamping, its induced ground vibrations can cause the unfavourable effects on nearby pipelines and buildings, ranging from annoyance to structural damage. Therefore studying the performance of barriers is inevitable. The majority of these vibrations spreads as of surface (Rayleigh) waves. By spreading out the generated surface waves, wave barriers can be a successful way to minimize these effects. Based on this and due to the lack of previous field studies on wave barriers in dynamic compaction, conducting practical tests and direct measurements of wave characteristics such as peak particle velocity are considered urgent needs by the engineering community in order to obtain wave barrier design solutions. The effectiveness of open trenches, empty holes, and trenches filled with geofoam in reducing vibrations brought on by dynamic compaction was investigated in an experimental field investigation. The dimensions of 10 × 12 m are deemed big enough within the context of our study area to capture the pertinent characteristics and phenomena related to dynamic compaction. To assess the isolation efficiency, key parameters, including the barrier geometries, and their locations relative to the vibration source were examined. The Larger barrier dimensions and the closer proximity of barrier to the vibration source the better screening effects. The experimental results showed that for the applied range of dynamic compaction energy (6 t.m), open trench barriers reduced peak particle velocity in vertical direction by 50% and geofoam-filled barriers reduced it by 20%, proving a good contribution in mitigation of the aftereffects in terms of induced vibrations. Moreover, void holes provided the least protection with about a 12% decrease in the energy transferred. The results of these experimental field studies can be useful for design purposes.