## 6 Conclusions and Discussion  
This paper develops a semi-analytical method to predict ground heave induced by shield tunnels passing through enclosure structures of existing tunnels considering the space effect. The proposed method is based on improved ground deformation theory combined with Kirchhoff plate theory. The proposed method is verified by comparing with the field measurements. The main conclusions drawn are as follows:  
1. The relationships between the deformation volume of the underground diaphragm wall and the ground deformation volume are first established. The deformation volume of the diaphragm wall is calculated using Kirchhoff plate theory, and the ground deformation volume is evaluated by the transverse deformation curve and longitudinal deformation curve. Further, the ground heave solutions at arbitrary position are obtained.
2. The proposed method is verified by field measurements from Wuhan Metro tunnel cases from China. In general, a good agreement has been observed for shield excavation-induced ground heave profiles and the predictions are good for normalized ground heave profiles. The maximum error is 14.6%, which is acceptable. Hence, the proposed method can be used as a feasible approach for the estimation of deformations induced by shield excavations.
3. The parameters of underground diaphragm walls are studied using the proposed deformation calculation method to determine reasonable design schemes for underground diaphragm walls. The elastic modulus of diaphragm walls has significant effects on ground heaves, while the thickness and embedded ratio of diaphragm walls has limited effects on ground heaves. As elastic modulus and the thickness of diaphragm wall increase, the ground heaves gradually decrease. In addition, the effects of the embedded ratio show a positive correlation. However, when the thickness and embedded ratio reach a certain value, they have little effect on ground heaves.
4. The presence of underground water has non-ignorable influences on ground deformation. So a new ground heave prediction method should be derived considering underground water seepage in the future.  
Figure 17: The effects of embedded ratio re of diaphragm wall on ground heave.  
**Author Contributions:** Methodology, J.Q.; software, J.Q.; validation, J.Q. and G.Z.; formal analysis, L.S. and P.Z.; investigation, J.Z. and L.S.; data curation, F.Z.; writing, J.Q. and G.Z.; supervision, Y.J.; project administration, Y.J.; funding acquisition, Y.J. and G.Z. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was sponsored by the National Natural Science Foundation of China (Grant Nos.: 41920104007, 42227805).  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Data are available on request due to restrictions, e.g., privacy or ethical concerns. The data presented in this study are available on request from the corresponding author. The data are not publicly available due to business reasons.  
**Acknowledgments:** The authors would like to thank [PERSON] for assistance in data collection and curation.  
**Conflicts of Interest:** The authors declare no conflict of interest.