JPS63233196A - Method of executing gallery - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention constructs a prestressed tunnel frame while excavating by obtaining the excavation reaction force of a shield machine from the hardened inner wall of an already installed tunnel. This is related to tunnel construction technology.

<Conventional technology> The technology of constructing a tunnel by using formwork to pour concrete on-site in a tunnel immediately after excavation using a shield machine is widely known.

By the way, when constructing concrete by pouring it on-site, the problem is where to obtain the digging reaction force of the shield machine.

Currently, a method has been proposed in which the digging reaction force of a shield machine is obtained from the formwork.

On the other hand, in order to prevent the collapse of the hole walls, it is necessary to apply pressure to the fresh concrete 1 that does not resist the collapse force of the hole walls and maintain it until the concrete hardens.

As a means for applying and maintaining pressure on concrete, methods of construction using jack pressure or pumping pressure using a concrete pump are known.

<Problems to be Solved by the Present Invention> The tunnel construction techniques described above have the following problems.

(b) Taking reaction force from weak concrete will have a negative impact on the quality of the lining structure.

(b) It cannot be removed from the mold until the lining concrete has hardened.

(c) It is possible to wait for the lining concrete to harden and obtain the digging reaction force of the shield machine from the hardened structure, but this will lengthen the construction period as work will be interrupted until the concrete hardens.

(d) In order to shorten the hardening time of concrete, materials with ultra-early strength are used, resulting in high construction costs.

(e) Since the jacking pressure and pumping pressure must be maintained until the poured concrete has hardened to a certain extent,
Reinforcing members such as reinforcing bars and steel frames cannot be placed inside the lining structure because jacking devices and pressure pipes get in the way.

(f) The smaller the cross-section of the tunnel, the more difficult it will be to construct it after demolding.

OBJECT OF THE INVENTION The present invention was made to solve these problems, and it is possible to obtain the digging reaction force of the shield machine without adversely affecting the lining structure, and also to improve workability and economy. excellent in sex,
Furthermore, the purpose is to provide a construction technology for tunnels that can be constructed with good strength and quality.

<Configuration of the Present Invention> An embodiment of the present invention will be described below with reference to the drawings.

First, we will explain the main equipment used for construction.

<A> Shield machine An example of a shield machine 1 is shown in FIG.

This shield machine 1 has a tail plate 12 protruding from the tail portion of the main body 11 at the rear of the main body 11.

The tail plate 12 is connected to a slide jack 13 fixed to the main body 11 so as to be slidable.

The shield machine 1 also includes a formwork moving jack 14, an excavation jack 15, and a press jack 16.

All of these jatsugi 13 to 16 are arranged in plurality in the circumferential direction inside the main body 11.

<Port> Reaction force device The tip of the digging jack 15 is connected to the reaction force device 2 for obtaining the digging reaction force of the shield machine 1.

As shown in Fig. 1.2, the reaction force device 2 includes a plurality of expansion/contraction tubes 2.
1, a connecting rod 22 having a telescopic function that connects these expandable tubes 21, and a running wheel 23.

Each cylindrical expansion/contraction tube 21 is made up of two arc-shaped split rings 24 and a plurality of jacks 25 interposed between the two split rings 24, and the diameter of each expansion/contraction tube 21 is adjusted by the expansion/contraction operation of the jacks 25. It is configured to scale.

In order to obtain the digging reaction force of the shield machine 1 from the reaction force device 2, a bracket 26 is provided at the front end of the reaction device 2 as shown in FIG. Connect one end of the rod 17 for use.

In addition, in order to prevent buckling of the bolt 17 of the digging jack 15, a plurality of locations in the middle -1- of the lot 17 are supported.

Specifically, for example, a support plate 18 having a hole sized to allow insertion of the rod 17 in the middle of the inner circumferential surface of the movable formwork device 3 is used.
A plurality of rods 17 are provided, and the rods 17 are disposed so as to pass through each support plate 18.

<C> Movable formwork device (FIG. 1) The movable formwork device 3 consists of a formwork moving jack 14 and a movable formwork 3 connected to the formwork moving jack 14.

The movable formwork 31 consists of a liner plate and circumferential ribs.

The reason why the movable formwork 31 is not provided with ribs in the longitudinal direction of the tunnel is to reduce the rigidity of the tunnel in the longitudinal direction to accommodate the forming curve of the tunnel.

The movable formwork 31 moves forward by the expansion and contraction operations of the formwork movement jack 14.

<2> Movable shoring device The movable shoring device 4 is a known shoring device having a traveling means to prevent the structure from collapsing immediately after lining.

When the movable formwork 31 is used to support the lining immediately after being cast, the movable formwork device 3 can also be used to omit the movable support device.

<E> Press ring (Fig. 3.4) The press ring 5 is an annular plate that cooperates with the movable form 31 to form a form, and the arc-shaped divided bodies are assembled into an annular shape. use.

The press ring 5 has an H-shaped cross section, and includes an inner ring 51 and an outer ring 5.
2 and a shielding plate 53 connecting the inner rings 51 and 52.

The plate surface of the shielding plate 53 of the press ring 5 has a plurality of holes 54.

This hole 54 is a guide hole for penetrating the end of the tendon material 6 buried in the lining structure and guiding it out of the formwork.

Further, as another press ring 5, it is also possible to use a type in which a continuous concrete layer 55 is adhered to the inner circumferential surface of an inner ring 51 and the outer circumferential surface of an outer ring 52 as shown in FIG.

Next, the construction method will be explained.

Kui> Process for obtaining excavation reaction force (Fig. 1.6) The reaction force device 2 is placed inside the already hardened lining 7, and then each expansion/contraction tube 21- is expanded in diameter to remove the hardened lining. Engineering lining 7
Crimp it.

In particular, in the present invention, instead of obtaining reaction force from the lining 7 that was cast in the previous process and has not yet hardened, the reaction force is obtained from a position several spans away from the lining 7 that was cast in the previous process. One of the features is that the reaction force for the digging of the shield machine 1 is generated from the lining 7 which has developed sufficient strength.

<Excavation> Excavation process A reaction force is obtained from the reaction force device 2 that presses against the hardened lining 7, and the excavation jack 15 is extended to advance the main body 11 of the shield machine 1 toward the face side.

Kuha〉The process of assembling the press ring After the shield machine 1 has finished moving forward, the excavation jack 15
to contract.

When the digging jack 15 is retracted, the free end of the digging jack 15 separates from the rod 17, creating a space in the tail plate 12 for assembling the press ring 5.

Next, the divided press ring 5 is carried in, and the movable formwork 3
1 and the tail plate 12.

When assembling the press ring 5, as shown in FIG. 7, a separate tendon 6b is connected to each tendon 6a protruding from the lining 7 constructed in the previous step via a connecting tool 61a, and this tendon 6b The free end of the press ring 5 is passed through the hole 54 to create silk.

2> Process of pouring concrete (Fig. 1.7) Set the press jack 16 on the press ring 5 located at the outermost end.

Next, the reaction force is obtained from the shield machine 1, and the movable formwork 3
1 to the face side.

As a result, a shielded space is formed between the tail plays 1 and 12 and the movable formwork 31.

Then, piping for concrete pouring is performed, and concrete is press-fitted into the shielded space formed between the tail plate 12 and the movable formwork 31.

Once the entire area of the shielded space is filled with concrete, the press jack 16 is extended and pressurized with a predetermined press pressure.

Step of applying prestress to the lining (Fig. 8) When the press jack 16 is extended, the press ring 5 retreats in a direction that reduces the body weight of the shielded space.

As a result, the concrete within the shielded space is pressurized and most of the excess water is drained away.

Furthermore, when the tail plate 12 is advanced toward the face side while continuing to pressurize the concrete, the concrete comes into close contact with the ground.

In order to maintain the pressurized state of the lining 7 immediately after casting, a model or nut-type fixture 62 is attached to the tension material 6 protruding from the press ring 5 and fixed, and then the press jack 16 is contracted.

As described above, in the present invention, the prestress applied to the lining 7 constructed in the previous step can be easily applied to the prestress.

Step of moving the construction device (FIG. 9) Next, the diameter of each expansion/contraction tube 21 of the reaction force device 2 is reduced to expose the running wheels 23.

Next, the digging jack 15 is retracted and the reaction device 2 is moved forward by one span toward the face.

While repeating each of the above steps, the lining 7 is successively extended and constructed alternately or in parallel during excavation.

Note that the movable shoring device 4 moves to the face side every time one span of lining 7 is constructed.

Effects of the Present Invention> The present invention provides the effects described above.

(a) The present invention is a system in which the digging reaction force of a shield machine is obtained from a hardened lining structure.

Therefore, there is no need to worry about unnecessary pressure acting on the lining structure and adversely affecting it.

(b) Perform construction by applying prestress to the lining structure in the direction of the tunnel.

Therefore, compressive force remains in the axial direction of the tunnel, and a strong structure can be constructed in the axial direction of the tunnel.

(c) Prestress is also applied to the lining structure in the circumferential direction, and the axial force is more dominant than the bending moment.

As a result, generation of tensile stress in the lining structure is suppressed.

(d) Since the concrete is pressurized, excess water in the concrete is discharged and the water-cement ratio is improved.

Therefore, the lining structure can be constructed with high quality.

(E) Since the concrete is pressurized between the tail play 1 and the movable formwork and then pressed onto another pile, the quality of the concrete is not affected by the properties of the ground.

(f) The forward movement of the shield machine and the forward movement of the tail plate can be performed separately and independently.

Therefore, construction can be carried out without matching the timing of concrete placement and the timing of excavation of the shield machine, which is advantageous in terms of construction.

(g) By using a prefabricated press ring, the next process can proceed without waiting for the concrete to harden.

Therefore, the construction period is shortened.

(h) Labor can be saved because the formwork, shoring, and reaction force device can be mechanically slid.

Automation is also easily possible.

[Brief explanation of drawings]

Fig. 1: Explanation of one embodiment of the present invention A perspective view of the second factor-two reaction force device Fig. 3 An explanatory view of the nib ring Fig. 4 A cross-sectional view of the nib ring Fig. 5: Another press ring Cross-sectional view No. 6N: Explanatory view of the reaction device when the diameter is reduced. FIG. 7. Partial cross-sectional view of the terminal end of the lining. FIG. 8;
Explanatory diagram when pressurizing the lining Figure 9 Explanatory diagram when moving the reaction force device Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims of Claims] In a method of constructing a tunnel by pouring concrete on-site between the ground formed by excavating with a shield machine and a movable formwork and lining the tunnel, expansion and contraction within the hardened lining is performed. A reaction force device consisting of a flexible cylindrical body is positioned, a telescopic jack is interposed between the shield machine and the reaction force device, and a movable formwork and a shoring device are interposed between the shield machine and the reaction force device. The shield machine is then excavated by obtaining a reaction force from the hardened lining, and then it is located on the extension of the end of the existing lining,
A split ring plate is assembled by passing through the tendons protruding from the end of the lining, concrete is poured into the space closed by the ring plate and the movable formwork, and then the ring plate is processed. A method of constructing tunnels in which the tunnel lining is fixed under pressure to tension members to apply prestress, and the excavation process with a shield machine and the process of lining the lining are repeated independently.