Due to the particularity of the tunnel project, it is difficult to find out the exact geological conditions of the tunnel body during the survey stage. Once it encounters unfavorable geological bodies such as faults, fracture zones, and karst, it will bring great challenges to the construction and will easily cause major problems, economic losses, and casualties. Therefore, it is necessary to carry out geological forecast work in the tunnel construction process, which is of great significance for tunnel safety construction and avoiding major disaster accident losses. This lecture mainly introduces the commonly used methods of geological forecast in tunnel construction, the design principles, and contents of geological forecast and combines typical cases to show the implementation process of comprehensive geological forecast. Finally, the development direction of geological forecast theory, method, and technology is carried out. Prospects provide a useful reference for promoting the development of geological forecast of tunnels.Keywords: advanced geological prediction design, content of advanced geological prediction, method of advanced geological prediction, geological hazard detection, engineering application 1. Stratigraphic lithology forecast, the focus is on prediction of soft interlayers, broken formation, coal seams, and special rock.2. Geological structure prediction, the focus is on the prediction of the tectonic development of the rock mass integrity, such as faults, concentrated joint band, and fold axis.3. Unfavorable geological prediction, the focus is on the prediction of karst, manmade tunnels, gas, etc.4. Groundwater prediction focuses on the prediction of karst conduit water and water-rich faults, water-rich fold axis, and fissure water in water-rich strata.Tunnel Engineering -Selected Topics
