Abstract: In order to reveal the changes of the earth pressure at the pile-soil interface during the penetration of the jacked pile in the cohesive soils, based on a pile project in Dongying, Shandong Province, a full-scale field test was carried out. The variation law of the earth pressure on the side of the pile with the penetration depth during the process of jacked pile sinking was obtained. The distribution characteristics of the earth pressure on the side of piles in different soil layers were analyzed. It is clear that the earth pressure on the pile sides has obvious degradation effect in the process of pile sinking. The relationship between the soil pressure at the pile sides and the overburden soil weight at the pile-soil interface was discussed. The results show that the earth pressure at the pile-soil interface is closely related to the soil properties. As the penetration depth of the sensor increases, the soil pressure on the side of the pile increases gradually, and the increase rate varies with different soil layers. At the same depth, the earth pressure at the pile-soil interface degrades obviously, and the degradation rate in silt soil is less than that in silty clay. In the same soil layer, the ratio of the earth pressure on the pile-soil interface to the soil weight on the pile-soil interface is constant, and the ratio in silt soil is obviously greater than that in silty clay.

Key words: jacked pile, earth pressure on pile side, degradation effect, field test