## 7 Conclusions  
On the basis of the Bailonggang sewage connecting pipe project in Zhuyuan, Shanghai, the effects of the jacking speed, tunnel face pressure, and pipe slurry friction coefficient deviation on stratum deformation were studied via field measurements and numerical simulation analysis. The conclusions are as follows:  
Under the maximum positive deviation and negative deviation of the jacking speed, after the tail passes through the monitoring section D\({}_{0}\) 16 ring, the settlement's extreme value at B8 increases by 21.6% and decreases by 12.8%, respectively. Increasing the jacking speed decreases the arch foot at the tail of the pipe jacking machine, increases the area with \(R<0\) at monitoring section D\({}_{0}\), and limits the influence of increasing the jacking speed on surface settlement control. When the pressure deviation of the tunnel face is small, only slight changes are observed when the tail passes through monitoring section D\({}_{0}\); the changes are less than 1%, the stress change ratio is essentially the same as the positive and negative boundaries of \(R\), and the effective stress does not change significantly. These two jacking parameters are negatively correlated with surface subsidence.  
Under the maximum positive deviation and negative deviation of the friction coefficient, after the tail passes through the monitoring section D\({}_{0}\) 16 ring, the settlement's extreme value at B8 decreases by 4.9% and increases by 16.5%, respectively. The area with \(R<0\) at monitoring section D\({}_{0}\) decreases with an increasing friction coefficient, resulting in an increase in the surface settlement value. After the jacking distance increases to a certain extent, the maximum surface settlement value is positively correlated with the friction coefficient of the slurry.  
Among the jacking parameters, the jacking speed has the strongest effect on surface subsidence, the pipe slurry friction coefficient has the second-strongest effect, and the tunnel face pressure has the weakest effect. When the tail of the machine passes through a section with strict surface deformation, the pressure of the tunnel face can be appropriately increased; after passing, the lower limit of the pushing speed should be strictly controlled.  
The confidence intervals of \(\alpha\) and \(\beta\) are 0.6\(-\)3.0 and 1.6\(-\)4.0, respectively. When the values of \(\alpha\) and \(\beta\) are in this range, the Peck-modified prediction curve is more suitable for the actual situation, and the prediction results are more reliable. The curve is also applicable to the prediction of surface subsidence in the other three intervals relevant to the project.  
Conceptualization, T.Z. and P.L.; methodology, T.Z.; software, G.C.; validation, G.C.; formal analysis, G.C.; investigation, T.Z. and D.N.; resources, T.Z. and D.N.; data curation, G.C.; writing--original draft preparation, G.C.; writing--review and editing, T.Z. and P.L.; visualization, G.C.; supervision, P.L.; project administration, P.L. and D.N.; funding acquisition, P.L. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Natural Science Foundation of China (grant No. 51868017).  
Not applicable.  
The raw data supporting the conclusions of this article will be made available by the authors on request.  
The authors wish to express their gratitude to the anonymous reviewers whose constructive comments helped to improve the overall quality of this paper.  
Conflicts of Interest: Author [PERSON] was employed by the company Shanghai Municipal Engineering Design General Institute (Group) Co., Ltd. The remaining authors declare that the re-search was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.