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R&C construction method

Tunnel construction method considering collection and exclusive use of shallow temporary materials

Outline of construction method

In the R&C method, the steel loop of the cross section (standard cross section 620x620, 800x800) is used as the protection form of the track or the road.
The installation of the loop penetrates into the whole length of anticipated transverse section according to the outer periphery of the structure, and a casing shoe (working face excavation workbench of steel) is installed on its end.
It is a method of installing an underground structure that excavates the inside of a structure, extrudes square pipe loop, and presses the structure as much as it is extruded.
In square pipe loop on the top of the structure, a friction cut plate is placed and fixed for cutting with surrounding ground, and square pipe loop and structure are moved and replaced at the bottom.

Features of construction method

1) Underground structures can be installed with a little cover soil.

- The structure and the upper part of square pipe loop are located at the same position, requiring less cover soil.

2) It is possible to make the approach short and low in the planning of urban planning roads

- Cover soil of the structure can be reduced, so the approach can be made shorter and lower in a structure with an approach. In addition, quantities such as temporary facilities, earthwork, concrete ball, and water countermeasures are reduced.

3) It is an economical method in terms of materials

- Square pipe loop is a temporary material and reused because it is recovered at the arrival base after use.

4) The arrangement of the FC PLATE does not interfere with the upper traffic.

- The example FC PLATE is installed and fixed on the upper part of the structure to prevent disturbance of the upper ground during propulsion or traction of the structure.

5) Working face excavation work is safe.

- The excavation site (working face) is safe because it is retained by the highly rigid square pipe loop

6) Maintenance of installed underground structures is unnecessary.

- Underground structure to be installed is a simple BOX CULVERT structure. High-quality can be controlled because the structure is made on the departure stand.

7) Possible to respond to all conditions

- Based on its abundant construction results, it can respond to a wide range of construction conditions, terrain, site problems and location conditions according to cross section extension, cross section, soil quality and construction time.

Propulsion type conceptual diagram

  • Nammyeon Underpass between Gimcheon and Daesin on Gyeongbu Line

    Width 10.3m x Height 6.4m x Extension 14.3m

  • Saburi Underpass between Hwanggan and Chupungnyeong on Gyeongbu Line

    Width 11.05m x height 6.845m x extension 15.00m

  • Naengjung Underpass between Namseonghyeon and Cheongdo on Gyeongbu Line

    Width 12.9m x height 6.8m x extension 18.5m

Construction flow chart of R&C method promotion type

  • FC PLATE member

  • Square pipe loop arrangement

  • FC PLATE STOPPER (Automatic control device)

1. Vertical aperture installation
2. Soft ground improvement (if necessary)
3. Propulsion of square pipe loop (simultaneous FC PLATE installation)
4. PIPE ROOF installation

5. Installation of propulsion equipment (departure base, reaction wall, casing shoe)

6. Production and installation of structures
7. Installation of re-storage loop (if necessary)
8. Installation of propulsion equipment (jack, reaction force jack, square pipe removal holder)
9. FC PLATE Fixation

10. Structure ball traction
11. Working face demolition, structure propulsion
12. Demolition of square pipe loop (per predetermined length)

13. Demolition of arrival base working face, structure ball traction
14. Demolition of propulsion facilities

Construction flow chart of R&C method traction type

1. Vertical aperture installation, loop support pile installation
2. Improvement of transverse section ground (if necessary)
3. Propulsion of square pipe loop (simultaneous FC PLATE installation)
4. Propulsion of steel pipe loop

5. Horizontal boring (For PC steel wire equipment)
6. Guide pilot tunnel drilling (if necessary)
7. Traction equipment installation (departure stand, casing shoe)
8. Structure production
9. Jack storage loop installation (if necessary)

10. Installation of traction equipment (jack, PC steel wire, reaction wall, roof demolition stand)
11. FC PLATE Fixation

12. Structure ball traction, Working face demolition, casing shoe penetration
13. tunnel face excavation, Structure pulling
14. Demolition of square pipe loop (per predetermined length)

15. Removal of arrival part working face
16. Demolition of traction equipment (jack, traction material, reaction wall)
17. Excavation between arrival base loop piles
18. Demolition of traction equipment (casing shoe, temporary facilities for roof demolition)

Ordering organization
Construction period