## 7 Conclusions  
In order to study the interaction between the pile and shield machine in the process of cutting reinforced concrete foundation, a calculation model of the interaction force is established in this paper. A field test of cutting two piles was conducted and the rationality of the model is verified by comparing the calculation results with field test data. The model is applied in an actual cutting-pile project in Harbin, China. The shield operation parameters are predicted and compared with field test results. Besides, the effects of cutting surface width and eccentric distance on the interaction force are discussed.  
1. The calculation and field test results show that when the shield machine cuts reinforced concrete piles, there is a significant interaction between the cutter head and the piles, which causes obvious changes in the shield operation parameters and shield performance.
2. The number of tools has a significant effect on the additional torque of cutter head. The additional torque fluctuates with the rotation of cutter head and increases obviously with the increase of the number of tools that are inside the cutting area. The number of these tools are also determined by the arrangement of tools, cutting surface width and eccentric distance.
3. As the cutting distance increases, the additional torque of cutter head shows a trend of first increasing and then decreasing and reaches the maximum value when the cutting distance reaches the radius of pile. The maximum additional torque from the field test in this paper is about 1000 kN\(\cdot\)m. This suggests that it is important to pay close attention to the torque and ensure that there is sufficient torque reserve.
4. The interaction force under different cutting surface width and eccentric distance conditions are given and discussed. The penetration force in the shield tunneling direction is usually greater than the unbalanced force in the other two directions. The additional torque of cutter head rotation is usually greater than the unbalanced moments in the other two directions as well. Besides, the additional force and additional moment of the cutter head increase with the increase of the cutting surface width. The impacts of eccentric distance on additional force and additional moment are complicated.
5. The additional force and additional moment given in this paper can provide reference for similar engineering. The discussion of the interaction between piles and cutter head under the conditions of different cutting surface width and different eccentric distances can provide guidance for the setting of shield operation parameters in other field projects with similar tools configurations and cutting conditions. However, the data given in this article are based on specific examples of project. The specific calculation and analysis of actual engineering conditions should be considered when findings of this study are applied to different projects.  
Figure 19: Effect of the eccentric distance \(e\) on the moments: (**a**) \(M_{x}\); (**b**) \(M_{y}\) and (**c**) \(M_{z}\).  
**Author Contributions:** Conceptualization, X.W. and D.Y.; methodology, X.W. and D.Y.; software, X.W.; validation, X.W. and D.Y.; formal analysis, X.W.; investigation, X.W. and D.Y.; resources, D.Y.; data curation, X.W.; writing--original draft preparation, X.W.; writing--review and editing, X.W. and D.Y.; visualization, X.W.; supervision, D.Y.; project administration, D.Y.; funding acquisition, D.Y. All authors have read and agreed to the published version of the manuscript.  
This research was supported by the Key Project of High-speed Rail Joint Fund of the National Natural Science Foundation of China under Grant No. U1834208.  
Not applicable.  
The data presented in this study are available from the corresponding author upon request.  
The authors extend their thanks to [PERSON] (CCCC First Harbour Engineering Co., Ltd.) for providing related data.  
The authors declare no conflict of interest.