Laboratory study on pile jacking resistance of jacked pile

Abstract

In order to explore the jacked pile penetration mechanism, in this study, a series of laboratory model tests of jacked pile in homogeneous cohesive soil were carried out. Based on the experimental data, the pile jacking resistance calculation formula was established. The variation law of pile end resistance, pile side resistance and pile jacking resistance during pile jacking was further obtained. Meanwhile, through the double-walled open model pipe pile, the “soil plug resistance” during the pile jacking process was separated. The influence of different pile diameters, different pile lengths and different pile end forms on pile jacking resistance during pile jacking was analyzed in comparison with closed pipe piles. The test results were compared with the theoretical predictions. The test results show that with the increase of penetration depth, the inner tube side resistance and the outer tube side resistance of the open pipe pile are gradually increased. The pile end resistance and the pile side resistance are mainly affected by the pile diameter and the pile end form, and the influence of pile length on pile end resistance and pile side resistance is not obvious. In the homogeneous clay soil layer, the pile diameter and pile end form have significant influence on the pile jacking resistance, and the pile length has little influence on the pile jacking resistance. The influence of different pile diameters, different pile lengths and different pile end forms on the pile jacking resistance in the laboratory model test better reflects the penetration mechanism of jacked piles in homogeneous cohesive soils. Furthermore, it is found that there is still some contingency in the laboratory test data, and the calculation formula of pile jacking resistance provides a theoretical basis for the laboratory test, which has a certain guiding significance for the laboratory model test.