Vibration Measurement and Prediction for Foundation Slab Design of a High-Tech Lab Based on In Situ Testing

摘要

Reduction of road traffic-induced vibrations has gained importance with rapid development of high-tech industry and nanotechnology. This study focuses on the in situ vibration measurement and transmissibility-based vibration prediction for the foundation slab design of a high-tech lab subjected to truck-induced vibrations. The truck-induced vibrations come from a proposed road 30?m away from the high-tech lab. The allowable vertical vibration velocity for the foundation slab of the high-tech lab was 60?μm/s in the frequency range of 5–50?Hz. The truck-induced ground vibrations in the proximity of an existing road with the same design as the proposed road were taken as the vibration source response used in the foundation design. The ground vibration transmissibility from the proposed road area to the high-tech lab area was determined by conducting frequency sweep tests in the free field. Based on the vibration source response and the ground vibration transmissibility, two antivibration foundation prototypes with different thicknesses were constructed at the site. The vibration transmissibility from the subgrade soil to the surfaces of the two foundation prototypes was obtained by measuring the ground vibrations at the high-tech lab area and the surface vibrations of the two foundation prototypes. The vertical vibration velocities of the two foundation prototypes were predicted based on the measured transmissibility and the vibration source response. The final thickness of the antivibration foundation was determined by comparing the predicted vibration velocities with the allowable vibration velocity. After construction of the high-tech lab and the road, vibration tests were conducted to assess the performance of the actual antivibration foundation. The results showed that the actual antivibration foundation was able to reduce the vibration levels at the high-tech lab to acceptable levels.