JPS6354876B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shield excavation method and an excavator therefor. This is used in the field of shield excavation, where a lining material is cast between a ring-shaped formwork and a tail plate to construct a tunnel wall.

[Prior art]

When constructing tunnel walls using lining material such as cement on the inside of an excavated tunnel, the formwork that has been divided in advance is assembled into a ring shape, and the lining material is placed between the formwork and the tail plate of the shield body. There is a shield excavation method, in which the formwork is removed after solidification and the tunnel walls are formed while excavating. One of the conventionally performed procedures is as follows. First, the shield body is stopped after excavating one ring width for pouring the lining material using the shield body. After reducing and retracting the shield jack, the worker uses an erector to assemble the formwork, which was created by dividing it in the circumferential direction, into a ring shape in the one-ring-width space in the tail plate, and then the formwork is inserted into the space between the formworks. Workers secure and assemble formwork rings. Then, extremely high strength cement reinforced by mixing steel fibers is poured between the formwork ring and the tail plate, and the injected lining material is moved back and forth between the formwork ring and the tail plate. Use a jack to press in the direction of the machine axis to promote densification and solidification of the lining material. Once the lining material has solidified, the formwork is removed, the shield jack is extended, and the shield body is advanced while absorbing the digging reaction force with the lining material.

According to this construction method, the lining material absorbs the excavation reaction force, so the next excavation cannot be carried out unless the placed lining material hardens, and in order to shorten the time, expensive Very early-strength cement must be used, which poses the problem of prolonging the construction period and increasing construction costs.

To solve this problem, a push rod is passed vertically through the part where the lining material is placed parallel to the machine axis.
There is a construction method in which a lining material is poured into the ring of the formwork after the formwork is assembled into a ring shape, and the buried push rod absorbs the digging reaction force. According to this, since the lining material does not take up the reaction force, there is no need for the lining material to be solidified during excavation, and as a result, early strength cement or ordinary cement can be used as the lining material, resulting in an inexpensive lining material. It is possible to shorten the construction period in addition to using materials. However, since the push rod must withstand the digging reaction force, it is heavy and difficult to handle. Therefore, it takes time and effort to assemble it into the pouring part, connect it to an existing push rod, and align its axes, and there is a problem that the excavation speed can only be achieved at a maximum of about 6 to 8 m/day. In addition, since a large number of push rods are used in one ring, their consumption becomes considerable, which hinders the reduction of construction costs.
Furthermore, there remains the problem that when the push rod is pressed by the reaction force of excavation, it contracts due to toxic deformation, causing the existing hardened lining material to collapse, and that the lining material deforms when the reaction force is released.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned problems, and its purpose is to cast a lining material between the ring-shaped formwork and the tail plate to provide a shield while constructing a tunnel wall. In the excavation method, it enables the use of inexpensive lining materials and speeds up the assembly of reinforcing bars and forms for reinforcing the lining materials.
In addition, it is an object of the present invention to provide a shield excavation method and an excavator therefor, which can excavate a tunnel without collapsing the cast lining material, thereby reducing construction costs and significantly shortening the construction period.

[Structure of the invention]

The features of the present invention will be explained below based on FIG.

The first invention is a shield excavation method in which a lining material 39 is cast between a ring-shaped formwork 24 and a tail plate 8a to construct a tunnel wall. Step 26 of pressing the existing formwork 24a to prevent the shield body 8 from moving; a step of pulling back the press ring 21 pressing the front end surface of the formwork 24 with the shield jack 20; and a step of using the formwork erection erector 31. a step of releasing the formwork 24 from holding it perfectly round and moving the erector device 25 forward;
A step of sequentially chucking the new split formwork 24 integrated with the arc-shaped reinforcing bar cage 36 and assembling it into a ring shape in the tail plate 8a, and holding the assembled formwork ring 24A in a perfect circle by the erector 31. At the same time, press ring 21 is attached to formwork 2.
4, the lining material 39 is cast into the formwork ring 24A, the gripper 26 pressing against the existing formwork 24a is reduced to enable movement of the shield body 8, and the shield This is a shield excavation method in which the steps of extending the jack 20 and excavating while taking the excavation reaction force with the formwork 24 via the press ring 21 are repeated in sequence.

The second invention is a shield excavator that constructs a tunnel wall by casting a lining material 39 between a formwork 24 assembled in a ring shape and a tail plate 8a. a press ring 21 that moves in the front-rear direction as the shield jack 20 expands and contracts therein;
a cylindrical ring 23 fixed to the ring girder 19 via a support 22 in parallel to the main body machine axis 8b;
It rotates on the outer periphery of the cylindrical ring 23 and slides in the front-rear direction, and assembles the split formwork 24 for lining material casting into a ring shape by chucking the split formwork 24 with an integrated reinforcing bar cage 36, and the assembled formwork. Erector device 2 that holds the ring 24A in a perfect circle
5, and a gripper 26 extending in the radial direction at the rear of the cylindrical ring 23.

〔Example〕

Hereinafter, the present invention will be explained in detail based on examples thereof.

Figure 1 is a sectional view of one embodiment of a shield excavation machine used to carry out the shield excavation method of the present invention, in which a lining material is placed between a ring-shaped formwork and a tail plate. This is a mud water type shield excavator that is used to build tunnel walls.
In the figure, reference numeral 1 denotes a cutter disc to which power from a hydraulic motor 2 is transmitted via a pinion 3 and a ring gear 4 to rotate, and a face 6 is excavated by a number of cutter bits 5 fixed to the front surface of the cutter disc. be. Reference numeral 7 in the cutter disk 1 is a copy-type overcut device that overcuts the ground 9 on the periphery of the shield body 8 during curved excavation. Such a cutter disk 1 is radially supported by a metal 11 interposed between the driving drum 1a and a bearing pedestal 10 fixed to the shield body 8, and the thrust load due to excavation is transferred to the front surface of the bearing pedestal 10. It is adapted to be received by a roller 12 mounted thereon. On the other hand, a sealing material 14 is interposed between the bulkhead 13 and the driving drum 1a,
The inside of the cutlet chamber 15 is made watertight. A mud feeding pipe 16 and a mud draining pipe 17 are installed in the bulkhead 13 so as to pass through it, and an agitator 18 is further installed to stir the soil shoved into the snail chamber 15 and promote its flow.
is provided. Reference numeral 19 denotes a ring girder for reinforcing the shield main body 8, and a plurality of shield jacks 20 are provided passing through this as shown in FIG. The shield jack 20 has a piston rod 20a that expands and contracts behind the ring girder 19, and a pressing shoe 2 is attached to the tip of the piston rod 20a.
0b is attached. A press ring 21 is disposed behind the press ring 21 so as to be movable within the tail plate 8a by rollers 21a shown in FIG. This press ring 21 moves in the front and back direction as the shield jack 20 expands and contracts, and when the shield jack 20 expands, the formwork 2
4 and closes the casting space for the lining material 39, and the reaction force when the shield main body 8 digs due to the extension of the shield jack 20 is absorbed by the formwork 24.
It is intended to be communicated to the public. In order to pull the press rings 21 back forward as the shield jacks 20 are reduced after one ring is dug, the press rings 21 are connected to, for example, every other shield jack 20 via pins 21b. This pin 2
1b is not shown in detail, but is inserted into the elongated hole of the connecting member 21c, and when the shield jack 20 presses the press ring 21, the end surface of the pressing shoe 20b directly contacts the side surface of the press ring 21. When the press ring 21 is pulled back, the shield jack 20 begins to shrink and the press ring 2
1, the press ring 21 moves forward via the pin 21b. Therefore, when the shield jack 20 is extended and exerts a digging reaction force on the press ring 21,
Care is taken so that no force is applied to the pin 21b. A support 22 is fixed to the ring girder 19, and as shown in FIG. 2, it has an arm shape so that an operator can move within the shield main body 8 and allow various attachments to be installed therein. As shown in FIG. 1, a cylindrical ring 23 parallel to the axis 8b of the shield main body 8 is fixed to this support 22, and a sludge pipe 16, a sludge drain pipe 17, and other hydraulic hoses are installed in the hollow part 23a. It is extended to the rear. This cylindrical ring 23 is equipped with an erector device 25 that rotates and moves back and forth in order to assemble the formwork 24 into a ring shape, and a gripper 26 that holds the existing formwork. Furthermore, if necessary, a cylindrical ring 23 is attached to the support 22 at the rear end.
A telescopic support leg 27 is installed to support the device in the event that it becomes cantilevered. Erecta device 25
is an outer cylindrical body 28 that rotates around the outer periphery of the cylindrical ring 23.
A drum 29 and a cylinder 30 as shown in FIG.
It consists of an arcuate formwork erection erector 31 that moves in the radial direction of the shield body 8 as it expands and contracts. A ring gear 32 for rotating the outer cylindrical body 28 around the cylindrical ring 23 is fixed to one end of the outer cylindrical body 28, and a motor 34 for driving a pinion 33 that meshes with the ring gear 32 is fixed to the cylindrical ring 23. There is. Further, a cylinder 35 is fixedly provided on the outer cylinder 28 to displace the drum 29 by the expansion and contraction of a piston rod 35a. The erector 31 has a built-in chucking portion (not shown) that grips the formwork 24, and an arcuate shoeing surface 31a (Fig. ) is formed.

According to the shield tunneling machine having such a configuration, it is possible to tunnel while constructing the tunnel wall through the following steps.

As shown in FIG.
6 is extended to press the existing formwork 24a in a Y-shape as shown in FIG. 6, thereby preventing the shield body 8 from moving. Next, as shown in FIG. 5b, the formwork 24b
The press ring 21 pressing the front end surface of the press ring 21 is pulled back by the shield jack 20 via the pin 21b (see FIG. 1). Then, the cylinder 30 of the formwork erecting erector device 25 shown in FIG. 5c.
(see FIG. 4) to release the perfect circle holding of the formwork 24b by the erector 31, and the outer cylinder 2
8 (see Figure 1)
Support erecta 31 by extending 2
Advance it to the vicinity of 2. In this state, as shown in FIG. 5d, the new split formwork 24c integrated with the arc-shaped reinforcing bar cage 36 is sequentially chucked and assembled into a ring shape within the tail plate 8a. As shown in FIG. 7, the reinforcing bar basket 36 is made of a plurality of reinforcing bars 37 arranged vertically and horizontally assembled in advance into a circular arc shape by welding or the like, and while the shield main body 8 is being dug, as shown in FIG. As shown in FIG. 2, it is integrated into the formwork 24c with bolts 38 or the like. The formwork 24 is a prefabricated steel box divided into one ring as shown in FIG. 9, and when the lining material 39 hardens as described later, it is removed from the tunnel wall and used to form a new ring. reused for. The divided reinforcing bar cage 36 and formwork 24 are chucked at once by the erector 31, and the drum 29 (the first
When the cylinder 30 (see figure) is rotated by a motor 34 and moved in a predetermined circumferential direction, the cylinder 30 is expanded and incorporated into the inner surface of the tunnel. The reinforcing bar baskets 36 have the same shape divided into approximately equal parts in one ring, but the shapes of the formwork 24 differ depending on the installation position and the installation order, as shown in FIG. 9. Of course, one ring may be divided into segments having the same circumference. When the reinforcing bar cage 36 and the formwork 24 are integrated and assembled one after another, the work lid 40 provided on the formwork 24 is opened as shown in FIG. Secure and make rough connections. Next, as shown in FIG. 5e, in order to hold the inner surface of the assembled formwork 24c with the erector 31, the cylinder 30 of the erector device 25 (see FIG. 4) is extended and fixed, and the formwork 24c is The purpose is to maintain the perfect circle of the formwork ring 24A formed by the above method. At the same time, the shield jack 20 is slightly extended to bring the press ring 21 into contact with the front end surface of the formwork 24c,
For example, normal cement or early-strength cement, which is the lining material 39, is poured into the form ring 24A through a lining material injection hole (not shown) opened in the form 24. After that, as shown in FIG. 5f, the gripper 2 pressing the existing formwork 24a at the rear
6 is reduced to enable movement of the shield body 8, and the shield jack 20 is extended as shown in FIG. When the excavation of one ring is completed,
Returning again to FIG. 5a, the operation is repeated in sequence. In addition, at the rear where the lining material 39 is solidified, the formwork 24d is solidified by the formwork removal erector 43 attached to the cylindrical ring 42 provided on the rear support cart 41, as shown in FIG. 5a. The lining material 39 is removed. At this time, care is taken to ensure that the gripper 44 in front of the erector 43 holds the front formwork 24e to facilitate its removal and prevent deformation of the formwork so that it can be reused. The formwork 24d removed by the erector 43 is conveyed by the roller conveyor 45 shown in FIG. 45, it is transported to the front erector device 25. All formwork 24 used for solidifying the lining material in this way is
If there are no irregularities on the outer surface as shown in Fig. 5 a to g, the number of formworks will increase, but the absorption of the excavation reaction force is achieved by the friction between the outer surface and the hardened lining material 39. You can take it. In the examples shown in FIGS. 1 and 9, there are two protrusions on each of the formwork 24.
4h is formed, a large reaction force can be transmitted to the solidified rear lining material 39 via the protrusion 24h. As a result, there is an advantage that the number of molds sufficient to receive the reaction force can be reduced.

According to this type of operation, even if the placed lining material has not solidified, the formwork can receive the excavation reaction force, and there is no need to wait for the excavation work until the lining material hardens. Also, there is no need to use expensive ultra-fast cement for the lining material. Furthermore, the reinforcing cage is assembled at the same time as the formwork, reducing the time required to assemble the ring.

Although the above-mentioned embodiment has been described using a mud water type shield excavator as an example, it can also be applied to a mechanical type excavator such as an earth pressure balance type excavator, or even a manual shield excavator. Furthermore, it goes without saying that the cutter disk is not limited to the one with the peripheral support structure as exemplified, but can also be applied to one with intermediate support or center drive structure.

〔Effect of the invention〕

As can be seen from the above detailed description, according to the shield excavation method and shield excavator of the present invention, it is possible to perform excavation by applying an excavation reaction force to the formwork even immediately after placing the lining material. As a result, no reaction force acts on the lining material, so it will not collapse, and the area of action of the pressed formwork can be made larger than that of the push rod mentioned in the prior art, so the surface pressure is low. As a result, the excavation reaction force can be dispersed, deformation of the formwork is extremely small, and therefore deformation of the lining material is also reduced, making it possible to achieve stable solidification of the lining material. Further, the reinforcing bars reinforcing the lining material can be used as reinforcing bar cages and assembled together with the formwork inside the tunnel, thereby shortening the work and reducing the labor involved. As a result, it is possible to excavate at a rate of approximately 12 m/day, which shortens the construction period, and by shortening the construction period and using inexpensive materials, construction costs can be significantly reduced.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of one embodiment of a shield tunneling machine that implements the method of the present invention, FIG. 2 is a cross-sectional view taken along the - line in FIG. 1, and FIG. 3 is a cross-sectional view taken along the - line in FIG. , FIG. 4 is a sectional view taken along the - line in FIG. 1, and FIG.
Figures a to g are schematic cross-sectional views showing each step in the shield excavation method, Figure 6 is a cross-sectional view taken along the - line in Figure 1, Figure 7 is a perspective view of a reinforcing bar cage, and Figure 8 is an integrated reinforcing bar cage. FIG. 9 is a front view of the formed formwork, FIG. 9 is an assembly state diagram of the formwork in one ring, and FIG. 10 is an explanatory diagram of the connection work in the circumferential direction of the reinforcing bar cage. 8...Shield body, 8a...Tail plate, 8b...Main shaft, 19...Ring girder,
20... Shield jack, 21... Press ring, 22... Support, 23... Cylindrical ring,
24, 24a to 24e...Formwork, 24A...Formwork ring, 25...Erector device, 26...Gripper, 31...Erector for formwork erection, 36...
Rebar cage, 39...Lining material.

Claims (1)

[Scope of Claims] 1 In the shield excavation method in which a lining material is cast between a ring-shaped formwork and a tail plate to construct a tunnel wall, after excavation for one ring is completed, the existing construction is carried out using a gripper. The process of pressing the formwork to prevent the shield body from moving, the process of pulling back the press ring pressing the front end of the formwork with the shield jack, and releasing the formwork from being held perfectly round by the formwork erection erector. At the same time, there is a process of moving this erector device forward, a process of sequentially chucking the new split formwork integrated with the arc-shaped reinforcing cage and assembling it in a ring shape in the tail plate, and a process of moving the assembled formwork ring to the erector. The step of holding the shield in a perfect circle while bringing the press ring into contact with the front surface of the formwork and casting the lining material inside the formwork ring, reducing the gripper pressing the existing formwork to prevent movement of the shield body. A shield excavation method characterized by sequentially repeating the steps of: making it possible to extend the shield jack and excavating while taking the excavation reaction force with a formwork via a press ring. 2. In a shield excavator that constructs a tunnel wall by pouring a lining material between a ring-shaped formwork and a tail plate, the shield jack expands and contracts in the tail plate behind the ring girder. A press ring that moves forward and backward, a cylindrical ring that is fixed to the ring girder parallel to the axis of the main machine via a support, and a reinforcing bar cage that rotates around the outer circumference of the cylindrical ring and slides back and forth. The split formwork for pouring lining material is assembled into a ring shape by chucking, and an erector device that holds the assembled ring formwork in a perfect circle, and an erector device that expands and contracts in the radial direction at the rear of the cylindrical ring. A shield excavator characterized by comprising: a gripper that performs