## 5 Conclusions  
To address the challenges arising from the construction of a shield pushing through a mining method tunnel, this study introduces a novel approach by conducting numerical calculations and analysis using finite element methods. It focuses on evaluating the combined structural system comprising the initial support, shield tube sheet, and shield guide table. According to the study, some suggestions are put forward for tunnel construction, and the conclusions are as follows:  
1. The bulk density of the initial support in the soil layer has a greater influence on its internal force than the buried depth, while Poisson's ratio has a weaker influence on the structure. The influence of the former should be considered first in the construction; that is, the excavation should be carried out in the soil with a depth of about 22 kN/m\({}^{3}\)and the initial support's thickness of 300 mm should be selected. Compared with the other initial support parameters of the tunnel [36; 37], material savings and structure optimization are realized, and the mechanical performance of the initial support is fully exerted.
2. The variation law of the segment under the influence of various factors is similar to that of the initial support and is weaker than that of the initial support. Therefore, the segment design standard can assist in the formulation of the initial support design standard. The research shows that the backfill gap of the segment should be controlled to be 300 mm corresponding to the mutation point, which is similar to the parameter law in the existing research [38], so as to prevent damage to the structure caused by the sudden change in internal force.
3. The weight of the shield machine is often limited by equipment specifications. Therefore, the control points of the design standard are mainly placed in the thickness of the guide platform, and the specific thickness is 200-250 mm. Different from the analysis of the thrust system [39], length [40], and other parameters of the shield machine by most scholars, this study provides a reference for the design standard of guide platforms.  
Conceptualization, E.D. and L.Z.; methodology, R.F.; software, R.F.; validation, E.D., L.Z. and R.F.; formal analysis, R.F.; investigation, E.D.; resources, R.F.; data curation, R.F.; writing--original draft preparation, E.D.; writing--review and editing, E.D. and L.Z.; visualization, E.D.; supervision, L.Z. All authors have read and agreed to the published version of the manuscript.  
This work was financially supported by the National Natural Science Foundation of China (5204104); the Sichuan Science and Technology Program (2023 YFH0022); the Opening Fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology (SKLGP2021K009); the Major research and development project of Metallurgical Corporation of China LTD in the non-steel field (2021-05); the Sichuan University postdoctoral interdisciplinary Innovation Fund.  
Not applicable.  
The datasets generated for this study are available from the corresponding author upon reasonable request.  
The authors of this work are grateful for the experimental help provided by the Key Laboratory of Deep Earth Science and Engineering, Ministry of Education.  
The authors declare no conflict of interest.