Abstract: To investigate the impact of the navigation channel on the stability of the adjacent pile foundations and surrounding soils, a typical bridge project of the second channel of the Beijing Hangzhou Grand Canal was taken as the research object. Numerical analysis methods were used to investigate the influence of the soil excavation and the channel water injection on the deformation of the adjacent bridge pile foundations and the water pressure of the surrounding soils. The results indicate that excavation of the soil will lead to a decrease in the soil water pressure, and the deeper the soil is buried, the more significant the change in the water pressure caused by the excavation. The excavation of the channel soil will cause the horizontal displacement of the pile foundation towards the channel side, affecting the stability of the pile foundations. As the water injection height of the channel increases, the water pressure of the soil inside the channel gradually increases, and the water pressure of the soil outside the channel shows a trend of first decreasing and then increasing. Moreover, there is a lag effect of the water injection on the water pressure supplement of the soil in the channel. The water injection into the channel will significantly affect the horizontal displacement of the pile foundation of the overpass bridge. The smaller the pile depth, the greater the impact of the water injection into the channel on the horizontal displacement.

Key words: Deep Soft Soil Site, Navigation Channels, Pile Foundations, Soil Water Pressure, Numerical Analysis