JPS6221989A - Excavation method of shielding excavator - 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 (a) Industrial Field of Application The present invention is directed to constructing a lining with cast-in-place concrete, and to construct a reaction force buried in the lining in the excavation direction of a tunnel. This article relates to an excavation method using a shield excavator, which uses a bar to remove reaction force and excavate.

(b) Conventional technology Usually, when a lining is constructed with cast-in-place concrete, a shield is removed from the poured concrete until the poured concrete reaches a predetermined strength. You can't take the reaction force. Then, during the construction,
A proposal has been made to bury a reaction force rod in front of the tunnel in order to absorb the reaction force, and to use the reaction force rod to absorb the reaction force caused by the excavation of the excavator.

(C)0 Problems that the invention attempts to solve In this method,
Regardless of the strength of the concrete that is cast to construct the lining, the reaction force required for the excavator to dig can be taken from the lining that has already been constructed.
Reaction force rod and shield [If the position of the digging jack on the excavator side does not match exactly, it will not be possible to take the reaction force in good condition, so a high degree of accuracy is required for the installation of the reaction force rod. This causes the inconvenience that the installation work requires a lot of effort and time.

In order to solve the above-mentioned drawbacks, the present invention makes it possible to take the reaction force in a good condition even if the arrangement of the reaction force rod and the excavation jack do not match exactly, so that the installation of the reaction force rod can be carried out easily. The purpose of this invention is to provide a method for excavating with a shield excavator, which can be carried out in a short time without much effort.

(d) Means for solving the first problem, that is, the present invention focuses on the fact that the above-mentioned inconvenience occurs because the excavation jack and the reaction rod directly abut and engage, and the reaction rod (17a ) When obtaining a reaction force for digging from the urethral jack (7) and the reaction rod (17a), a press that can be brought into abutting engagement with the jack (7) and the reaction rod (17a) A ring (9) is interposed between the press ring (9) and the press ring (9).
) to obtain the reaction force for digging.

Note that the numbers in parentheses are for convenience and indicate corresponding elements in the drawings, and therefore, this description is not limited to the descriptions in the drawings. The following r (el
The same applies to the column ``, action''.

(e) 0 effect With the above-described configuration, the present invention can provide shield 1 bending 1 (2
), the press ring (9) abuts and engages with the digging jack (7) and the reaction rod (17a),
It acts as a stress transmitting member.

(f), Example - Embodiments of the present invention will be described below based on the drawings.

Figure 1 is a diagram showing an example of a tunnel excavation site to which the present invention is applied, Figure 2 is a sectional view taken along the line ■-■ in Figure 1, and Figure 3 is a
FIG. 4 is an enlarged view showing details of the tail void injection pipe portion, and FIG. 5 is a plan view of FIG. 4.

At the site in front of the tunnel 1, as shown in Fig. 1, a shield excavator 2 having a cylindrical outer shell 3 is installed. is supported by Inside the outer shell 3, a plurality of digging jacks 7 are arranged along the outer shell 3, which has a circular cross section.A ram 7a of the intermediate jack 7 can be freely driven to protrude in the directions of arrows A and B. It is set in. As shown in FIG. 3, the rear end of the outer shell 3, that is, the right end portion in FIG. 1, is provided with a ring-shaped inner shell 11 having a predetermined thickness.
1 is provided with a plurality of tail void injection devices 10 along the inner periphery of the outer shell 3 at a predetermined angle.

As shown in FIGS. 4 and 5, the tail void injection device 10 has a slide tube 10a.
An injection valve 10b is provided at 0a so as to be slidable in the directions of arrows A and B. The injection valve 10b has a drive cylinder 10c.
piston rod], Od is connected, and the injection valve 10b has a bypass hole], Oe and injection hole], O
f is provided. A check valve 1 is installed at the tip of the injection hole 10f.
0g, and pipes 10b and 10i are connected to both sides of the slide tube 10a.

On the other hand, a pedestal 13 is constructed in the tunnel 1 which has been laid out in front of the garden in one bending direction of the tunnel 1, and at the forefront of the pedestal 13, a press ring 9 formed in an annular shape as a whole is attached to an arm. The arm 13a is supported in a manner that allows movement in the directions of arrows A and B and rotation in the directions of arrows E and F around the arm 13a to some extent. Press ring 9 has
As shown in FIG. 2, a fitting groove 9b is formed around the entire circumference, and a connecting rod 9a connected to the arm 13a is provided at the center thereof. Further, the frame 3 is provided with a formwork attachment/detachment device 15 movable along the tunnel 1, and the formwork removal/detachment device 15 is provided with an erector 15a. Further, a ready-mixed concrete supply pipe 16 is laid along the tunnel 1 on the pedestal 13, and a nozzle 16b is attached to the tip of the ready-mixed concrete 1 supply pipe 16 for spraying through a hose 16a.

Furthermore, the lining 17 of the tunnel 1 is made of cast-in-place concrete, and within the lining 17, as shown in FIG. has been done.

The reaction rod 17a1, as shown in FIG. 1, has a unit length Ll.
The rods 17c are connected and installed continuously along the construction direction of the tunnel 1, and the connection position CP of adjacent rods 17c is relative to the pouring surface 17b of the cast-in-place concrete of the lining 17. The shape is shifted in the length direction of the tunnel 1.

Since the shield excavator 2 etc. has the above configuration,
When the shield excavator 2 excavates the tunnel 1 by one bend, the ram 7a of the excavation jack 7 is first driven to protrude in the direction of arrow B, so that the tip of the ram 7a abuts and engages with the press ring 9. Further, in this state, when the ram 7a is projected in the B direction, the press ring 9 is pushed in the B direction by the pressing force of the ram 7a, and moves in the B direction. Then, the insertion groove 9
During b, the tip of the reaction rod 17a installed in the lining 17 is fitted into engagement. In this state, when the ram 7a is further driven to protrude in the B direction, the shield 1 bending machine 2 receives a reaction force in the A direction from the reaction rod 17a via the excavation jack 7 and the press ring 9.

This reaction force is sufficient to cause the shield l garden front machine 2 to dig because the reaction rod 17a is buried in the lining 17 that has already been constructed. In addition, since the press ring 9 swings to some extent in the direction of the arrow EXF around the arm 13a, even if the protruding state of the ram 7a or the installation state of the reaction rod 17a are slightly uneven in the A and B directions, the press ring 9 can be properly adjusted. It is possible to take reaction force in this state. Furthermore, even if the arrangement of the ram 7a and the reaction rod 17a is misaligned in the circumferential direction or diametrical direction of the tunnel 1, the press ring 9 in contact with both acts as a stress transmitting member, so that the reaction force is not transmitted. This can be done smoothly via the press ring 9. In order to evenly transmit the reaction force, it is desirable to interpose elastic means such as hard rubber in the fitting groove 9b of the press ring 9 that comes into contact with the reaction rod 17a and in the part that comes into contact with the ram 7a. .

Next, when the hydraulic motor 6 is driven to rotate the cutter 5, a reaction force in the direction A causes the face 19 facing the cutter 5 to rotate.
A portion of the excavator is removed, and the entire rolled excavator 2 is moved in the A direction at the same time. When the shield Niwamae machine 2 passes in the incoming direction, the ram 7a moves to B in synchronization with it.
It is projected in the direction, and the rolled excavation is performed from the reaction rod 17a side @z
The Okoro reaction force transmitted to the side is always maintained at an appropriate value, and is therefore adjusted so that an appropriate forward motion can be performed.

In this way, when the Niwazen machine 2 has dug a certain distance in the direction A, move the 7a back in the direction A,
In this state, the press ring 9 is moved in the A direction, and a new rod 17c is connected to the tip of the rod 17c on the leftmost side of the reaction rod lea, which was in contact with the press ring 9 until then. At the same time, a cylindrical lining 17 is constructed as a result of the excavation of the shield i garden front machine 2.
7e is arranged along the inner shell of the shield excavator 2.

In this state, the formwork 20 divided into segments by the erector 15a of the formwork attachment/detachment device 15 is
The concrete casting space 21 is formed between the formwork 20 and the inner M11 by placing and connecting the concrete casting space 21 around the formwork 20 and the inner M11. As shown in FIG. 3, the formwork 204 has a predetermined vAL of 3, and is formed into an arc shape that matches the curvature of the inner circumference of the lining 17 to be constructed. By arranging and connecting them to the circular cross section of the tunnel l, a cylindrical frame 22 with a width L3 and an outer diameter D is formed. The assembled formwork 22 is connected in directions A and B, which are the construction directions of the lining 17, to form a cylindrical connected formwork 23 as shown in FIG.

After the concrete placement space 21 is formed, early strength concrete is sprayed into the concrete placement space 21 from the nozzle 16b via the fresh concrete supply pipe 16 and the hose 16a. This work is carried out on the left side of the concrete casting space 21 in Figure 1, that is, on the outside of the face side (
This is done by spraying early-strengthening concrete from the opened area toward the end face 17d of the lining 17 that is already in the constructed state (therefore, this area becomes the pouring surface 17b of the lining 17), and the end face 17d Since the concrete sprayed on the concrete will harden immediately, the concrete with early strength concrete 1-
The pouring from 1 to 21 is performed by laminating early strength concrete in the A direction starting from the end face 17d. In addition,
Since early strength concrete starts solidifying immediately after being sprayed, the sprayed concrete will not flow out from the open face side.

In this way, the connecting portions of the rods 17c, 17c are also buried in concrete, and concrete is sprayed into the concrete placement space 21 from the end surface 17d of the lining 17 over the length L2, and the concrete is again buried for excavation. Jyatsuki 7
The ram 7a is driven to protrude in the direction of arrow B, so that the tip of the ram 7a abuts and engages the press ring 9. Then, as described above, the reaction force in the direction A is received from the reaction rod 17a via the press ring 9, so the cutter 5 is rotationally driven.
Start digging in direction A again.

Note that when the seal 1z excavator 2 starts digging in the A direction, the outer shell 3 and the inner shell 11 also move in the A direction, and as shown in FIG. 4, the moving inner shell 11 is already in a solidified state. The 17th section of the lining that has reached this point is moved and left underground. In addition, after the rolled excavator 2 moves, the outer shell 3 and inner shell 1 are
Since a tail void 25 having a width L4 corresponding to the thickness of 1 is generated, the drive cylinder 1 of each tail void injection bag W10
0C to move the piston rod 10d backward in the direction A in FIG. 4, and move the injection valve 10b in the direction A along the slide tube 10a. Then, since the pipe 10h and the injection hole 10f are aligned, the injection agent is injected into the tail void 25 through the pipe 10h, thereby preventing the surrounding ground from collapsing. Note that when the injection from the tail void injection device 10 into the tail void 25 from the injection pit is completed, the drive cylinder 10c causes the screw rod 1 to
0d is driven to protrude in the B direction, and the injection valve 10b also moves in the B direction. Then, pipe 1. Since Ob and the pipe 10i communicate through the bypass hole 10e, the pipe 10h
A cleaning liquid such as water is flowed toward the pipe 101 to remove and clean the injection agent inside the pipe 10h.

During this process, the concrete in the right part of the connecting formwork 23 in Figure 1 solidifies sufficiently and reaches practical strength, so shield excavation [2] excavates in the direction of the designated path gIA and concrete is poured again. When doing so, the rightmost set frame 22 in the figure is removed from the connected form frame 23, and the formwork attachment/detachment device 15 is moved to position the erector 15a under the separated set frame 22. , the assembled formwork 22 is disassembled into each formwork 20. The formwork 20b disassembled in this way is transported in the incoming direction by the formwork attachment/detachment device 15, and is connected to the assembled formwork 22 at the left end in FIG. 1 of the connecting formwork 23 at the site where the reinforcing bars 17e are newly installed. Reassemble in the shape and form the conc' J-1 - pouring space 21,
Reused.

(已) 1. Effects of the Invention As explained above, according to the present invention, the reaction rod 17a
When obtaining a reaction force for digging, a press ring 9 is interposed between the digging jack 7 and the reaction rod 17a, so that the press ring 9 can abut and engage with the jack 7 and the reaction rod 17a. Ram 7a.

Therefore, even if the positions of the jack 7 and the reaction rod 17a do not match exactly, the press ring 9 engages with both.
Since it plays a role as a stress transmitting member, the reaction force is transmitted smoothly, and it becomes possible to take the reaction force in a good condition. Furthermore, since the installation of the reaction force rod 17a does not require a high degree of accuracy, the effort and time required for the installation work of the reaction force rod 17a can be greatly reduced.

[Brief explanation of the drawing]

Figure 1 is a diagram showing an example of a tunnel excavation site to which the present invention is applied, Figure 2 is a sectional view taken along the line ■-■ in Figure 1, and Figure 3 is a
4 is an enlarged view showing details of the tail void injection pipe portion, and FIG. 5 is a plan view of FIG. 4. 2. Nord excavator 7... Excavation jack 9 Press ring 17 - Lining 17a Reaction bar Applicant Mitsui Construction Co., Ltd. Agent Patent attorney Phase 1) Shinji Figure 2 2 Shield/Scrap Reel'' ′-10c Fig. 3 2 length -! Grain, scraping layer, Fig. 4 Fig. 5) ○h

Claims (1)

[Scope of Claims] A shield excavator that excavates by pressing the excavation jack of the shield excavator against a reaction rod buried in the lining, and taking the reaction force for excavation through the reaction rod. In the digging method, when obtaining a reaction force for digging from the reaction rod, a press ring is interposed between the excavation jack and the reaction rod, which can abut and engage together with the jack and the reaction rod. An excavation method using a shield excavator configured to obtain a reaction force for excavation through the press ring.