Vibration barriers for shock-producing equipment

Abstract

Most modern manufacturing facilities have hammers or presses in addition to precision cutting equipment as their production machinery. Foundations supporting hammers and presses experience powerful dynamic effects. These effects may extend to the surroundings and affect labourers, other sensitive machines within the same facility, or neighbouring residential areas. To control vibration problems, wave barriers may be constructed to isolate vibrations propagating to the surroundings. This paper examines the efficiency of both soft and stiff barriers in screening pulse-induced waves for foundations resting on an elastic half-space or a layer of limited thickness underlain by rigid bedrock. The effectiveness of concrete, gas-cushion, and bentonite trenches as wave barriers is examined for different cases of soil layer depth, trench location, and embedment of the foundation. The model was formulated using the finite element method, and the analysis was performed in the time domain. The efficiency of different types of wave barriers in vibration isolation for shock-producing equipment was assessed and some guidelines for their use are outlined.Key words: hammer foundation, impact load, gas-cushion trenches, concrete trenches, soil–bentonite trench, finite element modeling.