Effect of Vibration Barrier Arrangements on Controlling Vibrations in Shock-producing Equipment

Hammers or presses commonly used in modern manufacturing facilities produce remarkable vibrations during their operation. Foundations supporting these machines experience powerful dynamic effects which may extend to the surrounding areas and affect workers, sensitive machines within the same facility, or the neighboring residential areas. To control free-field impact-induced vibrations, wave barriers may be constructed in the vicinity of the vibration source. This paper examines the efficiency of soft barriers (open trenches) on screening pulse-induced waves for foundations resting on a deep elastic layer or a layer of limited thickness underlain by rigid bedrock. The effectiveness of open trenches as wave barriers is examined for different cases of soil layer depth, arrangement for double trenches, and trench location.A 2D finite element model is constructed and some parametric analyses are performed in the time domain. Different arrangements of wave barriers in vibration isolation for shock-producing equipment are assessed for their efficiency. The results show that using the second trench could remarkably reduce the vibration amplitude. Finally, some guidelines are defined for their use.