Free Field Ground Vibration Due to Ground Improvement Induced Vibration

The present study focused on measuring free-field vibration induced by ground improvement work. Ground improvement work at the Indian Institute of Technology Patna campus was performed using the vibroflotation technique. Two different types of sensors were used to measure this ground accelerations and peak particle velocity (PPV). The minimum source to site distance of the recorded free-field peak ground acceleration (PGA) and PPV was 20 m and 10 m respectively. However, the data were recorded up to a maximum distance of 94 m for PPV and 70 m for PGA. The measured peak acceleration has been varied between 12 mm/s² to 4010 mm/s², and peak particle velocity varies between 0.08 to 5.94 mm/sec. The results indicate that the peak particle velocity reduces rapidly with the distance and about 93% reduction occurs in PPV at 56 m distance. However, the peak acceleration reduces by 80% approximately at about 58 m distance from the source. It has been concluded from the results that with the increase in the distance from the source, the reduction in PPV is more significant as compared to PGA.