Field measurement and FE prediction of vibration reduction due to pile-raft foundation for high-tech workshop

High-tech industry is having severe requirements on vibration control to ensure the smooth functioning of the high-precision instrument. This paper investigates the reduction of vibration due to the pile-raft foundation through field measurement and FE (finite element) prediction for a high-tech electronics workshop in Suzhou China. Ground vibration tests before the construction of the structure and floor vibration tests after construction are both carried out. The tests results are compared to reveal the effectiveness of the pile-raft foundation on vibration reduction; and FE simulation results are compared with the tested data, so as to evaluate the performance of current model. The investigation shows that, the pile-raft foundation exerts an overall positive action on the ground vibration control, since it averages the gap between floor vibration and the VC-B (vibration criterion-B) curve. Current FE prediction model has satisfying prediction of the horizontal vibrations at frequency higher than 6 Hz, but exaggerates the vibration isolation effectiveness of pile-raft foundation for vertical and horizontal vibrations lower than 6 Hz.