Study on the Effect of Multi-Row Pile Geometric Parameters on the Effective Isolation Zone

Ground vibration negatively affects both residents’ health and the operation of sensitive equipment, particularly in areas adjacent to transport infrastructure. Currently, multiple-row piles are commonly employed for vibration isolation; however, there is limited research on their vibration isolation zone (VIZ). This paper conducted field tests to examine the relationship between the geometric configuration of piles, such as pile length, spacing, row distance, arrangement, and number, and the VIZ. Using two-dimensional contours of the amplitude reduction ratio ( Ar ), this paper defines the effective vibration isolation zone (EVIZ) as an area where Ar ≤0.45. The findings indicate that the EVIZ increases with longer pile lengths and more rows, but decreases with wider pile spacing and greater row distances. Moreover, diamond layouts are found to be more effective than rectangular layouts in expanding the EVIZ. Recommendations include maintaining a pile length to Rayleigh wavelength ratio between 0.58 and 0.87, and ensuring pile spacing and row distances are less than 0.12 and 0.11 times the Rayleigh wavelength. This research offers valuable insights for designing multiple-row pile systems.