Abstract: In the process of pile jacking, the rate of jacking governs the degree of the soil disturbance adjacent to the pile. But few published studies considering the effect of jacking rate on the deformation of soil adjacent to the pile. By using a transparent soil material and the Particle Image Velocimetry (PIV) method, a series of visual model tests were conducted to analyze the displacement field and its evolution process of the soil around piles at different pile jacking rates. The results indicate that the soil displacement patterns demonstrate a dynamic process of the downward extrusion to lateral extrusion and to upward extrusion at different pile jacking rates. The reason for the variation of disturbance range at the initial and later stages of pile-jacking is that the high stress zone is produced ahead of the time under the tip of high-speed pile-jacking, and the disturbance range of the high-speed pile-jacking is slightly larger than that of low-speed pile-jacking. The general motion trend of the soil around the pile is upward, and the greater the velocity of pile jacking and the closer the distance to the pile, the greater the vertical displacement of the soil. The research results can provide a technical support for a reasonable design of the pile jacking rate and assurance of the construction quality and safety.

Key words: Jacked Pile Installation, Transparent Soil, Pile Jacking Rates, Model Test, Displacement Field