•Nonlinear models were used to study the flow field distribution and particle motion on slopes.

•The model includes three regions: runoff, highly permeable soil, and weakly permeable soil.

•Sensitivity analysis indicates that erosion is affected by runoff depth, slope angle, soil permeability, particle diameter, specific gravity, and stacking angle.

•The mechanical model of fault activation induced by roadway excavation was established with the plane strain theory.

•The loading rate relationship between the numerical simulation model and field scale was developed.

•The influence of fault angles and roadway excavation speed on the fault instability was investigated.

•A neural network combining principal component analysis (PCA) and gated recurrent unit (GRU) is proposed to provide accurate prediction of rock mass classification in tunnel boring machine (TBM) tunneling.

•The PCA–GRU model runs in approximately 20 s, which enables quick prediction of rock mass classification in TBM tunneling.

•The PCA–GRU model shows stronger generalization, making it more suitable in conditions where the distribution of various rock mass classes and lithologies change in percentage.

•In view of the limited theoretical research on the load model of initial support for horseshoe-shaped prefabrication, taking the Luochuan Tunnel on the Xi’an-Yan’an newly built railway as the background, theoretical research was carried out and numerical analysis methods were used to study the load model, damage, plastic zone, deformation, and critical thickness of the initial support structure for horseshoe-shaped prefabrication. The results indicate that under the same boundary conditions, the ultimate bearing capacity of the prefabricated assembly initial support is higher than that of the shotcrete initial support, resulting in larger ultimate deformation capacity of the prefabricated assembly initial support.

•In this study, the aim is to comprehensively understand the mechanical and seepage characteristics of filled rock joints.

•We accurately evaluate the safety and stability of rock engineering.

•We focus on the latest research on defective rock deformation and destruction mechanism.

•A brief description of the seepage characteristics of fracture-filled rocks, revealing the role of stress–seepage coupling, is presented.

•Future development trends of rock with filled fissures regarding rock damage, fracture mechanics, and fracture water emergence are envisioned.

•Adjusting the fineness and content of fly ash can control the hydration process and properties of fly ash slurry, including coagulation, strength development, and pore distribution uniformity, thereby optimizing construction efficiency and environmental performance.

•A project of twin overlapping shield tunnels with a small curve radius is introduced.

•Protective measures of soil grouting and H‐shaped steel supports are proposed.

•A 3D model in view of overcutting soils, grouting, and steel supports is established.

•The performance of the overlapping shield tunnel with a small curve radius is evaluated.

•The evolution of mesostructural characteristics of sandstone under dry–wet cycles is observed.

•The meso-damage deterioration mechanism of sandstone under dry–wet cycles is analyzed.

•The damage changes in the whole process of rock deformation and failure are obtained.

•The rock damage intrinsic model under the coupling of dry–wet cycles and load is proposed.