Tunnel construction subject to surrounding rock squeezing deformation can induce support cracking, intrusion, and collapse. Herein, the existing Wushaoling tunnel of Lanzhou–Wuwei second line railway and the new Wushaoling tunnel of Lanzhou–Zhangye third and fourth line railways are compared to analyze and discuss the progress in deformation control techniques for railway tunnels surrounded by squeezing rock. Further, a technical system for large deformation control is preliminarily established. The maximum support deformation of the Wushaoling tunnel do not exceed the reserved deformation. The large deformation of tunnel surrounding rock is generally controlled to achieve better support effect. The main control measures are as follows. (1) The section design method based on the deformation classification is suitable for squeezing surrounding rock. (2) The support structure design involves anti-releasing and early controlled releasing, and measures such as increased support stiffness, increased reserved deformation, and multi-layer supports can be employed. (3) The micro-bench method reduces the closure time of the inverted arch to control deformation. (4) To realize quick excavation and support and reduce the disturbance to the surrounding rock, a cantilever excavating machine can be used for excavation and an intelligent arch trolley can be utilized to realize unmanned vertical arch drilling, anchoring, and grouting.

To ensure the construction and operational safety of tunnel undercrossing multi-situational goafs, the Huaying Mountain High-Speed Rail Tunnel, a critical section of the Xi’an-Chongqing High-Speed Railway, was taken as a case study. Based on a three-dimensional finite difference numerical simulation platform, twelve situations were established to analyze the effects of three factors: distance, scale, and angle. The stability analysis was conducted by examining the displacement and deformation characteristics of the surrounding rock, stress changes, and axial forces of the initial support for each situation. The results show that in tunnel undercrossing multi-situational goafs, the vertical deformation, horizontal convergence of the surrounding rock, and the maximum axial force of initial support are all affected. Within a certain range, changes in distance significantly impact subsidence and settlement deformation of the surrounding rock. However, as the distance increases, the horizontal and vertical displacements of the tunnel and the axial force of the initial support tend to decrease. Conversely, the scale and angle of the goaf have an opposite effect on the surrounding rock: as the scale and angle increase, the stability of the surrounding rock deteriorates. In this case study, when the distance exceeds 1.13 times the tunnel span, the influence of the goaf on the stability of the surrounding rock gradually decreases. When the angle exceeds 45°, vertical displacement decreases, and the increasing trend of horizontal displacement gradually diminishes. The conclusions of this paper can provide guidance for designing reinforcement schemes for tunnels crossing through multi-situational goafs. The findings provide valuable insights and guidance for similar engineering projects.

The application of folding arch frames is deemed crucial for unmanned arch frame erection, with the selection of the joint form being a determining factor in the overall mechanical performance of the folding arch frame, particularly in influencing the primary support safety. In light of the geological conditions of the New Wushaoling Tunnel project, three feasible joint forms for folding arch frames were proposed: buckle, adhesive, and interference-fit joints. Numerical simulations were conducted to analyze the arch’s overall mechanical and the joints’ local mechanical performances, aiming to identify the optimal joint form. On-site construction data were collected, and the effectiveness of unmanned arch frame erection was evaluated. The design requirements for the vertical displacement results of the steel arches with different joints were met. The maximum shear stress of the buckled arch frame was found to be the lowest, whereas that of the interference-fitted arch frame was the highest. The local shear stress of the adhesive joints was the lowest, while that of the interference-fit joint was the highest. Considering the material application limitations and calculation results, buckle joints are recommended. Unmanned arch frame erection, compared with manual arch frame erection, can save 66.6% of human resources and reduce the construction time by 33.3% to 50%. Statistical analysis has confirmed that the quality of automated arch construction can be guaranteed.

Given the influence of air intake from inclined shafts in existing tunnel ventilation systems on train comfort and aerodynamic safety, a numerical analysis method is used to study the comfort and aerodynamic safety of operating trains under three conditions—inclined shaft closed and inclined shaft open without and with air intake—and to explore the variation law of transient pressure and aerodynamic force (lift coefficient, transverse force coefficient, and overturning moment coefficient). Combined with practical engineering and requirements, the influence of inclined shaft air intake on train operation comfort and aerodynamic safety is analyzed. Through this research, the influence of using air intake from the inclined shaft of an existing tunnel, a ventilation scheme of the new Wushaoling Tunnel, on the comfort and aerodynamic force of trains is revealed, and the comfort and aerodynamic safety of trains in an actual project are evaluated, verifying the rationality of the ventilation scheme of the Wushaoling Tunnel.