What types of work are there in tunnel construction?

The main types of work include: rebar worker, carpenter, concrete worker, scaffolder, welder, electrician, driller, mechanic, assembler, general worker, etc.

Tunnel construction method

1, traditional mining method

It is a construction method of drilling and blasting excavation and steel-wood member support.

2. Tunnel boring machine method

It is a tunnel boring machine equipped with a rock crushing cutter, which excavates the tunnel by mechanically crushing the rock and conveys the broken ballast out of the machine. It can be used for continuous tunnels.

3. Shield method

It is a kind of steel movable protective device or movable support, and it is a kind of machinery for building tunnels through weak aquifers, especially river bottom, seabed and urban center. Under its cover, the nose can safely excavate the stratum, and one excavation is equivalent to the width of a circle of assembled lining.

Prefabricated segments or blocks can be assembled at the tail, which can be quickly assembled into a tunnel permanent lining. The gap between the lining and the soil layer can be filled with cement grouting to prevent the continuous deformation of the surrounding strata and the increase of surrounding rock pressure.

4. Fill in as you dig

It refers to the construction method of digging the ground, excavating the earthwork from top to bottom to the design elevation, constructing the main structure of the tunnel from bottom to top, and finally backfilling the foundation pit or restoring the ground.

5. Cover excavation method

After digging down from the ground to a certain depth, the top is closed, and the rest of the lower works are constructed under the closed top cover. The main structure can be built forward or backward.

6, shallow excavation method

Referring to the basic principle of NATM, various auxiliary construction measures are taken to reinforce the surrounding rock during excavation, fully mobilize the self-supporting capacity of the surrounding rock, support immediately after excavation, and form a joint support system with the surrounding rock, which effectively inhibits the excessive deformation of the surrounding rock.

7. Waterproof wall

Also known as concrete underground wall and continuous middle wall. It connects the unit underground wall constructed in sections into a continuous underground wall, replacing the traditional wooden piles, steel piles and reinforced concrete piles, and has the functions of retaining soil, bearing capacity and waterproofing.

Extended data:

construction technique

1, presplitting blasting

During rock excavation, before blasting in the main blasting area, a through crack with a certain width should be broken on the design contour to buffer and reflect the vibration wave of excavation blasting, control its destructive influence on the reserved rock mass, and obtain a relatively flat excavation contour. This blasting technology is presplitting blasting.

Presplitting blasting is not only widely used in vertical and inclined excavation walls; Presplitting blasting is also used for regular surfaces, twisted surfaces and horizontal foundation surfaces.

2, presplitting blasting requirements

(1), the presplitting should be through, and the surface has a certain crack width. For medium hard rocks, the joint width should not be less than1.0 cm; ; The crack width of hard rock should reach about 0.5cm; However, in soft rock, when the joint width exceeds 1.0cm, the vibration reduction effect has not been significantly improved, so more field tests should be done to sum up experience.

(2) The roughness of pre-splitting surface after excavation shall not be greater than 15cm. Roughness of presplitting surface usually refers to the concave and convex degree of presplitting surface formed by presplitting holes, which is an important index to measure the rationality of drilling and blasting parameters and can be used to verify and adjust design data.

(3) The retention rate of hole marks on the presplitting surface shall be no less than 80%, and there shall be no serious blasting cracks in the rocks near the hole.

Baidu Encyclopedia-Tunnel Construction