What are the construction methods of tunnel support? There are many construction methods for tunnel support. Here are some common construction methods for tunnel support:

　　1. Anchor support: By drilling holes in the tunnel surrounding rock, inserting anchors, and using the tensile properties of anchors to enhance the stability of the surrounding rock. Anchors can be made of metal parts, polymer parts or other materials. The special structure of their heads and rods can play the role of suspension, composite beams and reinforcement.

　　2. Sprayed concrete support: After the tunnel is excavated, concrete is immediately sprayed on the surface of the surrounding rock to close the excavation surface and prevent the surrounding rock from loosening and deformation. Sprayed concrete can provide a certain support force and form a whole with the surrounding rock to jointly bear the surrounding rock pressure.

　　3. Steel support support: Steel structures such as steel arches and steel grids are used as supports, and are used in combination with sprayed concrete or anchors to enhance the support capacity of the tunnel. Steel support can provide greater rigidity and bearing capacity, and is suitable for situations with poor geological conditions or large deformation of the surrounding rock.

　　4. Advance support: Before tunnel excavation, the surrounding rock in front of the face is pre-reinforced to improve the stability and self-bearing capacity of the surrounding rock. Common advance support methods include advance small pipe grouting, advance anchor rods, etc.

　　5. Pre-reinforcement technology: The surrounding rock is pre-reinforced by grouting, soil nails, anchor cables and other means to improve its strength and stability. Pre-reinforcement technology can be carried out before or during tunnel excavation.

　　6. Secondary lining: After the initial support is completed, secondary lining construction is carried out to increase the durability and stability of the tunnel. Secondary lining can be made of materials such as concrete or reinforced concrete.

　　In actual construction, the appropriate support method should be selected according to the geological conditions, design requirements and construction conditions of the tunnel, and the construction should be carried out strictly in accordance with the construction process and quality requirements to ensure the safety and stability of the tunnel.