# Model Tests on Jacked Pile Penetration Characteristics Considering a Static Press-in Piling Machine
## 4 Conclusions  
In contrast to the conventional model test exclusively addressing a jacked pile, the inclusion of a static press-in piling machine has an influence on the process of pile jacking, and it is more in line with engineering practice. Through comparative analysis of the data, the following conclusions can be drawn:  
1. The overall distribution law of the stress characteristics of the pile during the pile jacking process is basically the same. However, under the effect of the static press-in piling machine, the results are different from the conventional model test. When compared with the test that only considers the pile, the pile pressing force, the pile end resistance, and the total side friction resistance of the pile are relatively high. Additionally, the proportion of the total side friction resistance to the pile pressing force increases when the piling machine is considered. 2. The pile jacking resistance is also affected by the static press-in piling machine. Under the influence of the piling machine, the pile end resistance and the pile side resistance have been increased to varying degrees. Although it is uneven, the growth rate of the total side friction resistance is accelerated when the pile sinking depth is 20 to 30 cm. 3. The distribution trend of the axial force of the two piles is also basically the same. When considering the influence of the static press-in piling machine, the axial force of the pile exhibits an increasing trend in conjunction with its decreasing rate. 4. When analyzing the influence of the static press-in piling machine on the unit side friction resistance of the pile body, it is found that the resistance relatively increases when the piling machine is considered. However, the phenomenon of \"side resistance degradation\" decreases. The reduction in \"side resistance degradation\" is the greatest at a depth of 20 cm to 30 cm, and this reduction gradually diminishes with increasing soil depth. 5. The soil pressure around the pile generally increases first and then decreases. When the pile sinking depth reaches the buried depth of the soil pressure gauge, the soil pressure value is the largest. The farther away from the pile, the smaller the earth pressure, showing a linear decreasing trend. At the same time, the soil pressure around the pile also increases when the static press-in piling machine is considered. 6. According to the theory of \"adhesion-plough\" proposed from the perspective of tribology, it can effectively explain the reasons for the change in experimental data under the action of a static press-in piling machine compared to the static pressure single pile and provide a theoretical basis for the test data. The analysis of the above shows the impact of the static press-in piling machine on the pile jacking, emphasizing the importance of selecting a suitable piling machine model in practical applications. This will enhance the accuracy of estimating pile jacking resistance prior to construction and assist in establishing a better understanding of the coupling mechanism between the piling machine and the quality of pile jacking in practical applications. Future research can also involve conducting jacked pile model box tests to investigate soil compaction effects while considering the impact of the piling machine. By utilizing numerical simulations and field tests, the influence of various combinations of pile machine models, pile types, and soil layers on penetration characteristics and soil compaction effects can be analyzed. Furthermore, the research findings on jacked piles can be extended to other pile installation methods, such as bored piles and static drilling root piles, in order to establish a comprehensive theory on the collaborative fusion of piling machine, piles, and site soil layers. This will further strengthen the interdisciplinary collaboration between civil and mechanical disciplines, enhancing the applicability and scope of the research. Conceptualization, Y.L. and R.Z. ; methodology, R.Z. ; validation, R.Z., Y.D. and Y.L.