The landslide at the entrance of a railway tunnel is large scale, and serious diseases are prone to appear under natural disasters, which threaten the safety of the tunnel. According to its characteristics, on‐site long‐term monitoring experiments and numerical analysis were carried out, and the mechanism of interaction between landslide and tunnel engineering was analyzed. The results show that under the impact of rainfall and earthquake, the original internal stress balance in the landslide body is disturbed, leading to the increase in landslide thrust and damage of the tunnel lining. Simultaneously, the excavation of the tunnel can slack the surrounding rock to increase the landslide thrust and make the landslide be finally formed; this landslide conversely acts on the tunnel, resulting in deformation and destruction of the tunnel. During the monitoring, under the influence of rainfall and earthquake, the stress of the secondary lining was continuously increased by 25%. Tunnel construction caused a maximum deformation of 30 mm in the antislide pile at a distance of 2.12 m, and the slope and the tunnel were also affected. Under extreme conditions such as rainfall and earthquake, shear failure occurred at the vault, bottom, and waist of the right‐line tunnel located at the junction of soil and rock; at this time, the tensile strength of the tunnel reached 93.8% of the limit value of concrete, which seriously affected the safety of the tunnel. As for the weakened tunnel structure, measures such as dense planting and strengthening of concrete strength should be adopted to enhance the safety of the tunnel structure.

The landslide at the entrance of a railway tunnel in the southwestern region is relatively large, especially due to earthquakes and other factors, which are prone to severe disasters and threaten the safety of the tunnel. Through the long‐term monitoring test and numerical calculation analysis on‐site, the mechanism of the influence of the earthquake‐induced landslide on the characteristics of the tunnel’s force and deformation is studied. The research results show that the earthquake caused the landslide thrust to increase. Because of the existence of the supporting structure, the landslide thrust was consumed, and the remaining part resulted in the compression failure of the tunnel. During the seismic monitoring period, the stress loss of the antislide pile anchor cable was 3.73% and the stress of the second lining of the tunnel increased by 25%. Under the condition of extreme seismic, shear failure occurred at the vault, bottom, and waist of the right‐line tunnel, and the tensile strength of the right‐line tunnel reached 93.8% of the limit value. For the weak links of the tunnel structure, dense reinforcement planting and strengthening of concrete strength should be adopted to enhance the safety of the tunnel structure. While designing the supporting structure, the rock‐socketing depth of the antislide piles and the number of antislide piles should be considered a priority. The impact of the antislide pile spacing is relatively small.

The detection of subgrade distresses in ballastless track railways poses a formidable challenge due to the presence of steel interference caused by the unique characteristics of high-speed rail track slabs and the dense arrangement of the steel reinforcement mesh within them. Here, we aim to examine the influence of varying distribution patterns of steel reinforcement in ballastless tracks on the detection of subgrade distresses using ground-penetrating radar. Through a combination of on-site testing and forward modeling, this paper analyzes the interference of steel reinforcement on the detection of voids beneath the steel using electromagnetic waves. The research findings reveal that incident electromagnetic waves from the ground-penetrating radar experience attenuation near steel reinforcements, with only a fraction able to penetrate the surface layer and propagate into the subsurface through interstitial gaps between the reinforcing bars. Furthermore, this influence diminishes as the spacing between the reinforcing bars increases and the bar diameter decreases. When steel bars are distributed on the upper and lower layers, the detection results of the lower void are most significantly influenced by the interlocking of the steel bars in the two layers. These research results can offer theoretical and technical support for the detection of ailments in high-speed railway subgrades.

With the development of the Chinese railway, the high‐steep slope is irreversible to be faced; especially under severe conditions such as heavy rainfall and earthquake, this kind of slope is prone to geological disasters, which seriously affects the safety and stability of the bridge substructure. Aiming to this, long‐term monitorization and numerical analysis were carried out in this research, and the influence mechanism of the high‐steep slopes on the stress and deformation characteristics of the bridge structure was studied. The research results show that under the effect of rainfall and earthquake, the original stress balance in the high‐steep slope is broken, and the possibility of landslide thrust increases; under the comprehensive impact of residual landslide thrust, traction force at slope foot, vertical gravity of bridge slab and vehicle, and the bridge cap will deform. Besides, the deformation of the bridge pier exceeds the allowable lateral displacement of the top of the bridge pier, reaching 111.7%∼112.4% of the limit, which seriously affects the stability of the bridge structure and the safety of the railway service. Therefore, by increasing the support strength of the slope foot and the diameter of the bridge pile foundation, the traction force of the slope foot can be reduced, and the sliding resistance of the bridge pile foundation can be improved so as the safety of the bridge structure can be promoted.