Dynamic Effect of Machine Foundation Resting on Reinforced Sand Bed
摘要
This paper presents an experimental investigation of the dynamic effect of machine foundation resting on reinforced sand bed. With a precast concrete footing placed on a reinforced sand bed, various vertical modes of block vibration tests were performed. The tests were conducted in a 1.75 m × 2 m × 1 m test pit with a 0.5 m × 0.5 m × 0.3 m size of precast concrete footing. Three different cases, namely model machine foundation on unreinforced foundation bed, model machine foundations on geocell-reinforced soil beds with sand as infill material, and geocell-reinforced soil beds with quarry dust as infill material were considered. The tests were carried out using a mechanical oscillator at four different dynamic force levels. The impact of these reinforcement elements, as well as the foundation beds, resonant frequency, peak particle velocity, and peak vertical displacement, were investigated. The maximum percentage reduction of displacement is observed in the presence of GRC-2 as compared to the URC. With GRC-2 present, there is a 56.45% reduction in peak displacement compared to URC. Furthermore, when comparing with the URC, the GRC-2 condition is observed to lower the PPV by 62.35% at a distance of 0.5 m from the footing. As a result, this study proved that, in order to meet the two fundamental needs of machine foundation design, it is helpful to apply geosynthetics beneath the foundations to control peak displacement and tune the resonant frequency.