JPH04247200A - Lining process for shielded tunnel - Google Patents

Abstract

PURPOSE:To perform lining work of a shielded tunnel of quality, on-site set concrete by assembling reinforcing rods and setting concrete while maintaining the pressure of lining material always higher than the earth pressure or the water pressure of the mountain. CONSTITUTION:When a lining material C is set in an assembled reinforcement rod space R surrounded with the inner cylinder 21 of a shielding machine 10 and a molding frame 1 and a sub-frame 50, or when digging ahead with the shielding machine 10, the sub-frame 50 is pressed with a sub-frame pressing jack 60 under a pressure higher than the natural ground pressure. When assembling reinforcement rods U, a sub-frame support 70 for receiving the load exerted on the molding frame 1 is made to project in place of the sub-frame pressing jack 60 so that the pressure of the lining material C is always kept higher than the natural ground pressure.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a method for lining a shield tunnel, and in particular, it is applicable to a construction method for lining a shield tunnel using a lining material such as cast-in-place concrete. It is related to the construction method.

0002

[Prior Art] In the lining method for shield tunnels, the lining method using cast-in-place concrete is usually
Using a shield machine with a cylindrical outer shape, the ground is excavated with a cutter device installed on the front of the shield machine, and the peripheral wall of the excavated tunnel is covered with formwork at a predetermined interval, and this formwork and the above-mentioned The process of arranging reinforcing bars between the shield and the surrounding wall, pouring concrete, pressing the concrete by operating a pressing jack, and moving the entire shield machine forward is repeated.

By the way, in this construction method, a gable ring is provided at the tip of the pressing jack to close the space between the formwork and the tunnel peripheral wall. Since the concrete moves along with the rod, the concrete needs to be cured until it develops its strength, which increases the construction time.

[0004] As a means of solving this problem, the prior art has proposed an annular pressure retaining ring that takes reaction force in the cast-in-place concrete and maintains the compression of the concrete between the formwork and the tunnel peripheral wall. The patent discloses a means for embedding the shield in the lining material by holding it between the shields by tie rods (Japanese Patent Application Laid-open No. 190900/1999, "Place-casting shield excavator").

[0005]

[Problems to be Solved by the Invention] However, even with such prior art means, the following problems remain to be solved.

Firstly, in the prior art measures, the pressure retaining ring does not have an auxiliary formwork for adjusting the meandering of the shield, so there is a considerable gap in the pressure retaining ring and the pressure retention is not sufficient. There is no such thing.

Second, there is no pressure maintenance device to keep the concrete pressure higher than the underground pressure, so even if the pressure can be maintained at first, the pressure will gradually drop. It is.

The present invention was proposed in view of the above circumstances, and its purpose is to assemble reinforcing bars and pour concrete while always maintaining the pressure of the lining material higher than the soil pressure and water pressure of the ground. An object of the present invention is to provide a method for lining a shield tunnel, which can be easily installed and can perform high-quality lining.

[0009]

[Means for Solving the Problems] In order to achieve the above object, the present invention covers the peripheral wall of the excavated tunnel with formwork at predetermined intervals while excavating the ground using a cutter device at the tip of the shielding machine. , a shield tunnel lining method in which the inner surface of the tunnel is lined by placing reinforcing bars between the formwork and the peripheral wall and supplying lining material, the method comprising: lining the inner surface of the tunnel; of,
The structure is double formed by an outer cylinder and an inner cylinder, and a plurality of partition walls extending in the radial direction of the skin plate are formed between the outer cylinder and the inner cylinder of the tail part to form a plurality of concrete piston chambers in which the extrusion pistons are accommodated. A flange metal fitting which also serves as a terminal frame for arranging reinforcing bars inside the inner cylinder and closing the space between the inner cylinder and the formwork is set so that its outer end is in contact with the inner surface of the inner cylinder. After the gap between the inner end of the flange hardware that also serves as the end frame and the outer surface of the formwork is closed by protruding an auxiliary end frame from the inside of the formwork, it is surrounded by the inner tube, the formwork, and the end frame. When placing lining material in the reinforcing bar assembly room and when excavating the shield machine, the gable frame is pressed with a gable frame presser jack inside the shield machine at a pressure higher than the ground pressure, while the reinforcing bars are assembled. In such cases, in place of the gable hold down jack, a gable support that receives the load on the formwork protrudes from inside the formwork to maintain the pressure of the lining material higher than the ground pressure. Then, pour the lining material between the formwork and the ground from the concrete piston room, and when the pressure of the lining material in the reinforcing bar assembly room and the external lining material are equal, The frame is taken out, the lining material in the reinforcing bar assembly room and the external lining material are integrated, and a pressure holding jack is used to push out the piston in the concrete piston room until the pressure of the lining material is higher than the earth pressure and water pressure of the ground. It is characterized by making the shield machine dig while pressing so that

[0010] Furthermore, in the shield tunnel lining method, a formwork unit is constructed in advance by integrally assembling reinforcing bars and a flange metal fitting that also serves as the end frame on the outer periphery of the formwork, and this formwork unit is assembled. You can also do that.

[0011] In this case, a formwork unit in which reinforcing bars and a flange metal fitting that also serves as an end frame is integrally assembled on the outer periphery of the formwork is used as a wedge-shaped formwork unit that has a wedge-shaped formwork tapered in the width direction. a third formwork unit, a second formwork unit arranged on both sides of this wedge-shaped third formwork unit and tapered only at the joint surface with the wedge-shaped formwork, and this second formwork unit. It consists of three types of formwork units: a first formwork unit that is assembled in succession on the other joint surface of the After the frame units are successively assembled to the first formwork unit, the third formwork unit is finally inserted between the second formwork units and assembled to the second formwork unit. This is preferable because it improves efficiency.

0012

[Operation] According to the shield tunnel lining method according to the present invention, the pressure of the extrusion piston in the plurality of concrete piston chambers formed in the tail portion is individually controlled by a pressure holding jack, so that the lining material in each chamber is Since the pressure can be managed individually, it is possible to easily respond to differences in ground pressure due to height, and the pressure of the lining material can always be maintained higher than the earth pressure and water pressure of the ground. It becomes possible. Further, due to such an action, the tail void is reliably filled with the lining material, and there is no fear of subsidence.

Furthermore, when assembling the reinforcing bars, a flange metal fitting that also serves as the end frame is placed in contact with the inner surface of the inner cylinder of the shield machine, and an auxiliary gable frame is connected to the flange metal fitting that also serves as the end frame from the inside of the formwork. Since they are connected to close the space between the formwork and the inner cylinder of the shielding machine, even if the size of the gap between the inner cylinder and the outer periphery of the formwork changes due to meandering of the shielding machine, the auxiliary gable frame By adjusting the length, the meandering can be accommodated and the pressure of the lining material can be maintained reliably.

Furthermore, when pouring lining material and excavating, the gable frame is pressed by the gable frame presser jack, and when assembling reinforcing bars, the gable frame support reloads the load on the gable frame and pulls the gable frame presser jack. Since reinforcing bars and formwork are assembled together, there is no need to tie the newly assembled reinforcing bars to the previous reinforcing bars, and the reinforcing bars and formwork can be temporarily assembled together outside the mine.

[0015]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows the vicinity of the face of a tunnel that is currently under construction according to the present invention. In the figure, reference numeral 10 denotes a shielding machine, and this shielding machine 10 excavates a tunnel T on the left side of the drawing using a cutter device 12 provided at the front of the shielding machine 10, and forms a tunnel T at the rear of the shielding machine 10. The peripheral wall of the tunnel T is covered with a formwork 1 at a predetermined interval, reinforcing bars U are placed between the formwork 1 and the peripheral wall, and a lining material is supplied to form a lining wall W on the inner surface of the tunnel. is configured to build.

The formwork 1 is mainly composed of a face plate 1a and a support frame 1b that supports the face plate 1a, and the face plate 1a of a part of the formwork (upper formwork) has a mold. A joint part 1c for connecting a pouring pipe 2 for pouring lining material is provided on the outside of the frame, and a storage groove 1d and an insertion groove are provided for housing an auxiliary gable frame 51 and a gable frame support 70, which will be described later, in such a manner that they can appear and retract, respectively. A hole 1e is provided. Note that the joint portion 1c is provided with a shutter mechanism 3 that opens and closes the filling port of the joint portion 1c (
(See Figure 4).

Next, to explain in more detail the shielding machine for carrying out the tunnel lining method according to the present invention, as shown in FIG. 11, a cutter device 12 provided at the front end of the skin plate 11 and rotated by a drive means (not shown) to excavate the ground, and a base end connected to a partition plate 11a formed inside the skin plate 11. The basic structure is equipped with a propulsion jack 13.

The tail portion of the skin plate 11 is made up of an outer cylinder 20 having the same diameter as the skin plate 11 and forming a part of the skin plate 11, and an inner cylinder 21 having a smaller diameter than the outer cylinder 20. The outer cylinder 20 and the inner cylinder 21 are connected by a plurality of partition walls 22 extending in the radial direction of the skin plate 11, as shown in FIGS. 2 and 3.

[0020] And, between the outer cylinder 20 and the inner cylinder 21,
Multiple (four in the illustrated example) concrete piston chambers 23
are provided, and an extrusion piston 24 is slidably housed in each concrete piston chamber 23.

As shown in detail in FIGS. 1, 2 to 4, this extrusion piston 24 is inserted into the concrete piston chamber 23 according to the internal shape of the concrete piston chamber 23.
It is formed to a size that fits tightly within the partition plate 11a, and is configured to slide back and forth by a plurality of pressure holding jacks 25 whose base ends are attached to the partition plate 11a.

The pressure holding jack 25 that operates this extrusion piston 24 is equipped with a relief valve, so that the jack contracts when the casting pressure of the lining material becomes greater than the holding pressure of the jack. The structure is as follows.

Furthermore, a plurality of seal members 26 (two in this embodiment) are attached to the outer periphery of the extrusion piston 24, and the inside of the skin plate 11 and the inside of the concrete piston chamber 23 are attached to the center of the extrusion piston 24. A filling hole 24a of the lining material is formed to communicate with the
A joint portion 27 is provided that communicates with a and is connected to a pouring pipe 30 of lining material (see FIG. 4).

In the embodiment, the filling hole 24a is arranged at the center of the extrusion piston 24, but the present invention is not limited to this embodiment.

[0025] The filling hole 24a also has a filling hole 24a.
A blocking mechanism 28 is provided to open and close the filling hole 24a (see FIG. 4), so that the filling hole 24a can be opened and closed as required. Note that this blocking mechanism 28 specifically includes:
It consists of a shutter, a valve, etc., but the filling hole 2
Other configurations may be used as long as 4a can be opened and closed.

In FIG. 1, reference numeral 30 indicates a pipe for placing lining material, and one end of this pipe 30 is connected to a branch valve 33 connected to a supply pipe 32 of a supply pump 31 for lining material. In addition, the casting pipe itself is constructed of a flexible pipe or a telescopic pipe so that it can respond to the movement of the extrusion piston 24.

Furthermore, in the figure, the reference numeral 50 is a flange metal fitting that also serves as an end frame to close the space between the inner cylinder 21 and the formwork 1, and this flange metal fitting 50 that also serves as an end frame, as shown in FIG.
A plurality of plates 5 curved in accordance with the curvature of the inner surface of the inner cylinder 21
The basic structure is formed by combining 0a in a ring shape in the longitudinal direction.

Furthermore, the flange hardware 50 that also serves as the end frame
The inner end 50b is processed to be concentric with the outer end thereof, and the gap G between the inner end 50b and the outer periphery of the formwork 1 is the same as that of the shielding machine, as shown in FIGS. 4 and 5. Since the size changes with meandering, the size of the gap is set larger than the amount of meandering, and it goes without saying that care is taken to prevent the flange hardware 50, which also serves as the end frame, from being exposed inside the lining material. .

An auxiliary end frame 51 is set in the gap between the formwork 1 and the flange hardware 50 which also serves as the end frame.

A notch 51b (see FIG. 5) is provided at the outer end of the auxiliary end frame 51 to fit into the flange hardware 50 that also serves as the end frame, and when set with the flange hardware 50 that also serves as the end frame, this By aligning the notches 51b, the casting pressure of the lining material can be reduced by the flange hardware 50 which also serves as the end frame.
can be transmitted to.

Further, the auxiliary gable frame 51 may be attached by directly bolting to the formwork, or may be pressed from inside. If you force it from within,
Flange hardware 50 and inner cylinder 21 for use as gable frame during curve construction
By sliding the auxiliary gable frame 51, the displacement between the inner side and the inner side can be absorbed, so that curve construction can be easily performed.

Incidentally, this auxiliary end frame 51 is also basically composed of a plurality of plate bodies 5, similar to the flange hardware 50 that also serves as the end frame.
1a are combined in the circumferential direction to form a ring, and in the illustrated example, a tapered surface is formed at the joint of four plates 51a on the upper, lower, left and right sides, and a ring is formed from the inside of the inner cylinder 21. The auxiliary gable frame 51 can now be assembled (see FIG. 2).

By the way, in the figure, reference numerals 60 and 7
Reference numeral 0 denotes an end frame presser jack and a end frame support installed in the shielding machine 10 in order to resist the pressure of the lining material applied to the flange hardware 50 which also serves as the end frame.
(See Figures 1, 2, 3).

First, the end frame holding jack 60 applies rod pressure to the end frame flange hardware 50 when pouring lining material and when the shielding machine 10 excavates. is skin plate 11
A pressing part 60a attached to the internal partition plate 11a and provided at the tip of the rod of the end frame presser jack 60 can press the flange hardware 50 which also serves as the end frame. In addition, between the pressing parts 60a of each end frame presser jack 60,
Needless to say, a space is provided to eliminate interference with the gable frame support 70 (see FIGS. 2 and 3).
.

Next, the end frame support 70 is a rod-shaped member that holds the pressure acting on the end frame flange hardware 50 instead of the end frame holding jack 60 when assembling reinforcing bars and formwork, and is more effective. Specifically, FIGS. 10 and 11
The structure is as shown in .

That is, the end frame support 70 is a rod with a circular cross section that tapers so that the cross section becomes smaller toward its tip (upper end in FIG. 10). The tip of the support is inserted into a fitting hole 21a formed on the inner surface of the inner cylinder 21, so that the pressure applied to the flange metal fitting 50 which also serves as the end frame can be transmitted to the inner cylinder 21. And this support 70 for the gable frame is
When pulling out the support 70, the adhesive force can be easily broken by rotating the support 70 in the circumferential direction of the support 70.

Note that the support 70 for the end frame is not limited to the one having a circular cross section as shown in FIGS. 10 and 11, but may be formed to have an elliptical cross section as shown in FIGS. 12 and 13, for example. A gable frame support 70A can also be used. In this case, with the support 70A for the gable frame, first, the narrow side is facing the gable side, and finally, by rotating the support 70A and pressing the wide side against the gable side, the lining can be applied to the gable side. It can handle the pressure of the material.

Next, the shield machine 1 constructed as described above will be described.
A case in which the shield tunnel lining method according to the present invention is carried out by applying No. 0 will be explained in the order of steps with reference to FIGS. 4 to 9.

(1) Assembling reinforcing bars and formwork As shown in FIG. 4, with the propulsion jack 13 pulled, assemble the reinforcing bars U inside the inner cylinder 21, and install, for example, an erector inside the reinforcing bars U. to assemble the formwork 1 into a cylindrical shape (see Fig. 5).

On the other hand, as shown in FIG. 5, when the reinforcing bar U is assembled, a flange metal fitting 50 which also serves as an end frame for closing the space between the inner tube 21 and the formwork 1 is attached so that its outer end 50c is on the inner surface of the inner tube 21. The auxiliary gable frame 51 protrudes from the inside of the form frame 1 to close the gap between the inner end 50b of the flange hardware 50 that also serves as the gable frame and the outer surface of the formwork 1, and the gable frame The dual-purpose flange hardware 50 has a pressing portion 60a of the end frame presser jack 60 in order to resist the pressure of the lining material.
is pressed so that the pressure applied to the flange hardware 50 which also serves as the end frame is taken care of.

[0041] At this time, the propulsion jack 13 is attached to the formwork 1.
It is set in the formwork 1 so that the reaction force of the propulsion jack 13 can be absorbed.

[0042] In order to improve workability during assembly, it is preferable that the tip of the reinforcing bar U is fixed by a locking metal fitting 55 provided on the inner surface of the inner cylinder 21, and a flange metal fitting 50 which also serves as the end frame. It is preferable to integrate the reinforcing bar U and the reinforcing bar U in a factory or the like, since this will increase the ease of assembly.

It is also assumed that the reinforcing bars U are joined by lap joints. In addition, in the above, the outer end 50c of the flange hardware 50 that also serves as the end frame is processed to match the curvature of the inner cylinder 21, so by joining the outer end 50c to the inner surface of the inner cylinder 21, this part can be Although sealing performance can be ensured, a sealing material may be inserted between the outer end 50c of the flange metal fitting that also serves as the end frame and the inner cylinder 21 in order to further ensure the sealing performance.

By the way, in the above work, when assembling the reinforcing bars and assembling the formwork, as shown in FIGS. 4 and 5, the pressing part 60a of the end frame presser jack 60 is retracted, and the end frame support 70 is moved instead. is made to protrude from the inside of the formwork 1 and take charge of the pressure of the lining material applied to the flange hardware 50 which also serves as the end frame.

[0045] Gable frame presser jack 60 and gable frame support 7
0, it is necessary to apply these simultaneously when transferring the load of the lining material, but this will be done in the next step.

That is, the pressing portion 60a at the tip of the jack, which corresponds to the end frame portion, is adjacent to the pressing portion 6 of the end frame holding jack 60.
0a, and insert the end frame support 70 until its tip is inserted into the fitting hole 21a of the inner cylinder 21 (see FIGS. 2 and 10).

When the reinforcing bars and formwork have been assembled, the end frame holding jack 60 is pressed against the end frame flange hardware 50, the pouring pipe 2 is connected to the joint part 2, and the next process (to the reinforcing bar assembly room R) is carried out. Prepare for the process of placing lining material.

(2) Placing concrete in the reinforcing bar assembly room After completing the setting of the reinforcing bar U, formwork 1, flange hardware 50 that also serves as the end frame, auxiliary end frame 51, etc., pour the concrete through the pouring pipe 2 (arrow A) into the mold. The lining material (for example, concrete) C is transferred from the joint part 1c of the frame 1 to the reinforcing bar assembly room R, which is surrounded by the inner cylinder 21, the end frames 50, 51, and the formwork 1, as shown in FIG.
to be poured.

(3) Removal of the auxiliary gable frame and the support for the gable frame As shown in FIG. 7, after the concrete is poured into the reinforcing bar assembly room R, the pressure Pr of the concrete in the reinforcing bar assembly room R is
When the pressure of the external concrete becomes almost the same as Po, move the auxiliary gable frame 51 and gable frame support 70 at the rear of the reinforcing bar assembly room R toward the inside of the formwork 1 (as shown by the arrow), as shown in FIG. , b direction) and close the filling port 3 of the joint part 1c (arrow c). This operation ensures that the concrete being placed remains under pressure at all times. With the filling port 3 closed, the pouring pipe 2 is separated from the joint portion 1c. The timing of separation should be done by the time of next concrete pouring in the reinforcing bar assembly room.

(4) Preparation for pouring When pouring concrete externally, the extrusion pressure of the pressure holding jack 25 is adjusted to correspond to the difference in ground pressure depending on the height, so that the poured concrete always stays in the ground. Concrete piston chamber 2
Set it so that the lining material can be supplied to the tank.

Further, as the lining material, delay-type concrete or the like is used, and the setting is made so that the pressure is transmitted to the rear.

It goes without saying that the concrete piston chamber 23 is manufactured in advance with high precision in a factory, and the sealing member 26 is formed so as to withstand high pressure.

(5) Placing concrete into the concrete piston chamber As shown in FIG. 8, after preparation for concrete pouring is completed, concrete is sent to the pouring pipe 30 from the supply pump 31 and extruded through the pouring pipe 30. Concrete is poured into the concrete piston chamber 23 from the filling port 24a of the piston 24 (arrow A).

More specifically, the extrusion piston 24 provided in the concrete piston chamber 23 of the shield machine 10
The concrete pressure Po generated by the action of the extrusion piston 24 is adjusted by adjusting the pressing force of the pressure holding jack 25.
is maintained higher than the ground pressure Pj, and the pouring pipe 3
0 toward the concrete piston chamber 23 at a pressure greater than the pressure of the pressure holding jack 25, and concrete is poured into the concrete piston chamber 23.

[0055] At this time (when pouring concrete into the concrete piston chamber 23), the extrusion piston 24
is subjected to a force in a direction that opposes the pressing force of the pressure holding jack 25 due to the supply pressure of concrete, but the pressure holding jack 25 that presses the extrusion piston 24 is forced to stop when it receives a pressure greater than the set pressure. Since the extrusion piston 2 is provided with a relief valve that compresses the
4 moves to the front of the shield machine 10 as concrete is supplied, so that concrete placement is not obstructed. Moreover, when the supply of concrete is stopped, the pressing force of the pressure holding jack 25 acts on the extrusion piston 24 again,
As the shield machine 10 advances, it will move backward.

(6) Excavation of the shield machine Next, while extruding the concrete in the concrete piston chamber 23 backward, the cutter device 12 at the front end of the skin plate 11 excavates the ground, and the formwork 1 is propelled by taking the reaction force. The shield machine 10 is made to dig by driving the jack 13. At this time, the concrete pressure Po is the ground pressure Pj
Since it is larger than that, there is no need to worry about water leakage.

After the excavation is completed, as shown in FIG. 9, the support 70 for the gable is moved to the outside of the formwork (in the direction of arrow A in the figure), and the lining material (concrete C) applied to the gable is removed. Under pressure. Note that the method of setting this gable frame support 70 will be described later. Next, when all the gable supports 70 are moved and ready to receive the pressure of the lining material, the gable frame presser jack 60 can be retracted (arrow B).

Since the pressure of the lining material is maintained by the end frame support 70, the end frame (flange hardware 5 which also serves as the end frame)
0) will not break and accidents such as lining material spewing out will not occur. Thereafter, the necessary portions of the propulsion jack 13 are retracted, reinforcing bars, formwork, etc. are set in the same manner as described above, and such steps are repeated to proceed with the work.

It goes without saying that even after the excavation is completed, the pressure in the concrete piston chamber 23 is maintained constant by the pressure maintaining jack 25.

If it becomes necessary to replace the sealing member 26 of the extrusion piston 24 during the above process, after the concrete has hardened, the extrusion piston 24 can be pulled out from the concrete piston chamber 23 and the sealing member 26 can be replaced. Bye.

This operation is a simple operation in which the extrusion piston 24 is pulled out using the pressure holding jack 25 after the concrete has hardened, and the sealing member 26 on its outer periphery is replaced, and since the replacement work is performed after the concrete has hardened, it is safe. This can be done on-site.

Furthermore, when cleaning of the concrete pipe becomes necessary, the filling port 24a is blocked using the shutoff mechanism 28 attached to the extrusion piston 24, and the pouring pipe 3 is closed.
All you have to do is remove the 0 and clean it.

This work can be carried out while applying pressure to the concrete in the concrete piston chamber 23 because the blocking mechanism 28 can prevent the concrete from flowing out from the filling hole. Workability is not impaired.

In the embodiment described above, the tail portion of the shielding machine 10 is made double, a plurality of concrete piston chambers 23 are provided inside the tail portion, and an extrusion piston 24 is provided within the concrete piston chamber 23. Since the pressure in each concrete piston chamber 23 is adjusted by the pressure holding jack 25, the concrete pressure in each chamber is adjusted in response to changes in ground pressure (normally, the deeper the depth, the higher the pressure). The concrete pressure can be maintained at a higher level than the ground pressure at all times, reliably and easily.

In addition, in the embodiment, the concrete piston chamber 23 is provided in the tail section of the shielding machine, and the extrusion piston 24 is previously installed in the concrete piston chamber 23 in a sealed state so as to be slidable, so that the extrusion The accuracy of the seal portion of the piston 24 can be maintained at the same level as the seal of the movable parts such as the cutter of the shield machine, and it can be applied to almost all the geological formations that the shield machine can handle.

Furthermore, in this example, it is possible to safely and easily replace the seals that are important for maintaining the concrete pressure, so by replacing the seals even when excavating long distances, the concrete pressure can always be maintained. It has the advantage of being retainable.

Furthermore, in the embodiment, the extrusion piston 24 is moved forward as concrete is supplied, and moved to the rear of the shielding machine when extruding concrete, so that the pressure inside the concrete piston chamber is reduced by the concrete. It is now possible to maintain a nearly constant level even when supplying the material, and as a result, it does not apply excessive pressure to the ground or formwork, does not push up the ground, and also makes the formwork stronger than necessary. This has the effect of eliminating the need for it.

Furthermore, as described above, in the embodiment, it is possible to always maintain the pressure inside the concrete piston chamber 23 higher than the earth pressure and water pressure of the ground, so there is no water leakage and high-strength, high-quality concrete can be produced. It has the advantage that it is possible to cast concrete, and also that there is no risk of ground subsidence because the tail void can be filled reliably.

Furthermore, in the embodiment, the extrusion piston 24
Since the structure is such that the concrete is always pressed, it is possible to use concrete that takes a long time to harden, and there is also the effect that cleaning of piping etc. for each ring is not necessary.

Furthermore, in the embodiment, the pressure of the lining material applied to the end frame is controlled by the end frame presser jack 60 and the end frame support 70.
Since it is supported alternately by the gable frame presser jack 60 during excavation, the gable frame support 7 is used when assembling reinforcing bars and formwork.
There is also the advantage that each work can be carried out safely and reliably since it can be carried out by one person.

Further, in the embodiment, the space between the inner cylinder 21 and the formwork 1 is closed by the flange hardware 50 that also serves as the end frame, and the auxiliary end frame 51 that is joined to the flange hardware 50 that also serves as the end frame. Since the meandering of the shield machine is adjusted by adjusting the protrusion and retraction of 51, there is an advantage that workability can be improved.

Next, details of how to set the end frame support 70 on the inner peripheral plate (inner cylinder 21) will be explained.

The procedure for setting the gable frame support 70 is to extend the support 70 and form the upper end of the support on the inner surface of the inner cylinder 21 of the shield machine 10, as shown in FIG. 10, when the support 70 itself has a circular cross section. Insert it into the fitted groove 21a. By this operation, the upper reaction force of the concrete pressure is absorbed by the inner cylinder 21 through the engagement portion between the end frame support 70 and the fitting groove 21a.

Note that when the cross-sectional shape of the end frame support 70 is oval, the support 70A is first inserted into the fitting groove 21a.
When inserting it into the frame, make sure to leave a gap between it and the gable frame (Figure 12). And by this operation, support 70A
The support 70A can be smoothly inserted without the end frame and the end frame interfering with each other.

Next, the upper end of the support 70A is connected to the fitting groove 2.
1a, the support 70A is rotated in the circumferential direction as shown in FIG. 13, and the support 70A is pressed against the end frame so that it can reliably receive concrete pressure.

14 to 17 show an example in which the formwork 1 and the reinforcing bar U are integrated, and FIG. 14 is a front view and a diagram showing a method of connecting the flange hardware 50 which also serves as the end frame and the formwork 1. 15
1 is a front view showing a method of connecting reinforcing bars U and formwork 1. FIG.

In the illustrated example, the reinforcing bars U are a cage-shaped unit that integrates reinforcing bars V extending in the longitudinal direction of the tunnel and reinforcing bars W extending in the circumferential direction of the tunnel, and the reinforcing bars V are attached to the flange. It is fixed by being passed through the insertion hole of the hardware 50, and the length of the reinforcing bar V to be inserted is set to be slightly longer than the wrap length that will be required when the next reinforcing bar U is assembled. . Note that the reinforcing bars V and the flange hardware 50 have a structure in which they are fixed by welding, screwing, or the like.

On the other hand, the reinforcing bars W are attached to the reinforcing bars V by means such as welding or bundling, and the reinforcing bars W are
In order to integrate with adjacent reinforcing bar cages (reinforcing bar units), the flange hardware 50 is configured to protrude from the end portion by a length longer than the required wrap length.

Next, as for the means for integrating the reinforcing bar cage U and the formwork 1, in the illustrated example, a plurality of connecting hardware 80 (two at the front and the rear in the illustrated example) are applied. Specifically, this connecting hardware 80 has a structure as shown in FIG. 16.

That is, the connecting hardware 80 is screwed into a connecting rod 81 that connects the formwork 1 and the reinforcing bar cage U, and a male screw 81a at the upper end of this connecting rod 81, and is attached to the flange hardware 50 or the reinforcing bar cage U. a long nut 82 , a support member 83 fixed to the inner surface of the face plate 1 a of the formwork 1 and supporting the connecting rod 81 , and a male thread 81 at the lower end of the connecting rod 81 .
The upper and lower parts 2 that are screwed together with b and that fix the connecting rod 81 to the support member 83
It is mainly composed of nuts 84 and 85.

Note that the connecting rod 81 is connected to the face plate 1 of the formwork 1.
The male screw 81b at the lower end of the connecting rod 81 is formed to protrude longer than the lower end of the support member 83, thereby connecting the reinforcing bar cage U and the formwork 1. The position can be easily adjusted.

Further, the long nut 82 may be, for example, as shown in FIG.
Reinforcing bar W (V may also be used) using the mounting screw 82b attached to a.
It tightens and fixes. Note that when dismantling the formwork 1, the nut 84 may be loosened, the connecting rod 81 may be rotated to unthread the long nut 82, and the connecting rod 81 may be removed.

[0083] Therefore, such a reinforcing bar cage U and formwork 1
The procedure for lining a shield tunnel using a formwork unit integrated with the above is as shown in FIGS. 18 to 24.

First, FIG. 18 shows an example of dividing this formwork unit.Due to the structure of assembling this formwork unit inside the shielding machine 10, the formwork unit consists of the formwork 1 and the flange hardware 50. A wedge-shaped first formwork unit 100A whose both sides in the width direction taper upward as they go outward, and this first formwork unit 10.
A second formwork unit 100 in which one joint surface of the formwork 1 and the flange hardware 50 is inclined to be joined to both sides of 0A.
B and a third formwork unit 100C which is joined to the other joint part of the second formwork unit 100B and in which both the joint surfaces of the formwork 1 and the flange hardware 50 extend along the radial direction of the tunnel T. It is composed of three types of units.

In order to actually assemble these three types of formwork units in a tunnel, first, as shown in FIG.
A third formwork unit 100C located below 8 is connected in the circumferential direction, and a second formwork unit 100C is connected to the third formwork unit 100C.
By assembling the formwork unit 100B and finally incorporating the first formwork unit 100A, the formwork and reinforcing bars as shown in FIG. 18 are constructed.

FIG. 19 is a front view showing in more detail the arrangement of reinforcing bars in these formwork units, and the reinforcing bars W in the circumferential direction of the reinforcing bar baskets provided in each formwork unit 100A, 100B, and 100C are It protrudes from both sides of the flange hardware 50 to form a lap part of the reinforcing bars, and the outer periphery of the first formwork unit 100A is provided with this formwork unit 10.
It has a structure in which reinforcing reinforcing reinforcing bars W1 are provided separately from 0A.

20 to 23 show a more specific method of constructing the formwork unit, and FIG.
As shown in 9, these formwork units 100A, 100B
, 100C are assembled into a cylindrical shape, first, as shown in FIG. 20, a third formwork unit 100C is installed, and adjacent to this third formwork unit 100C,
As shown by arrow A in the figure, another third formwork unit 10
Drop in 0C. FIG. 21 shows a state in which two third formwork units 100C located below the tunnel are joined to each other.

Next, by the same operation, four third formwork units 100C are joined in the circumferential direction of the tunnel T, and as shown in FIG.
The second formwork unit 100B is joined on top of this. Second
As shown in FIG. 22, the formwork unit 100B is arranged so that one side of the reinforcing bars W of the reinforcing bar cage U (the side facing the first formwork unit 100A) is aligned with the end face of the flange hardware 50, and is positioned on the right side in the figure. Reinforcement connecting reinforcing bars W1 are attached along with the reinforcing bars W of the second formwork unit 100B.

[0089] Then, the second form unit 100B located on the left side in the figure is raised and rotated, and set on the upper end of the third form unit 100C.

[0090] Two second formwork units 100B, a third
After assembling the four formwork units 100C, the inner reinforcing reinforcing reinforcing bars W2 are assembled, and finally the first
formwork unit 100A to second formwork unit 100B
If it is inserted between them and assembled into the second formwork unit 100B, the constructed state of the formwork and reinforcing bars as shown in FIG. 19 is completed.

In the above example, the reinforcing bars V are located outside the reinforcing bars W, but it goes without saying that the same work can be done even if the reinforcing bars V and W are arranged in reverse, inside and out, as shown in FIG. It is.

[0092]

Effects of the Invention As explained above, the shield tunnel lining method of the present invention involves excavating the ground using a cutter device at the tip of the shielding machine, and then cutting the peripheral wall of the excavated tunnel using formwork at predetermined intervals. A shield tunnel lining method in which the inner surface of the tunnel is lined by placing reinforcing bars between the formwork and the peripheral wall and supplying lining material, the tail of the skin plate of the shield machine being covered. The part is double formed by an outer cylinder and an inner cylinder, and a plurality of partition walls extending in the radial direction of the skin plate are formed between the outer cylinder and the inner cylinder of this tail part, so that the extrusion piston can be accommodated in a plurality of concrete. A piston chamber is provided, and a reinforcing bar is placed inside the inner cylinder, and a flange metal fitting that also serves as an end frame to close the space between the inner cylinder and the formwork is set so that its outer end touches the inner surface of the inner cylinder. Then, after closing the gap between the inner end of the flange hardware that also serves as the end frame and the outer surface of the formwork by protruding an auxiliary end frame from the inside of the formwork, the inner cylinder, the formwork, and the end frame surround the gap. When pouring lining material into a reinforcing bar assembly room made of steel and when excavating with a shield machine, the gable is pressed by a gable frame presser jack at a pressure higher than the ground pressure inside the shield machine, and on the other hand, When assembling reinforcing bars, instead of using the gable hold down jack, a gable support that receives the load on the formwork is protruded from inside the formwork.
The pressure of the lining material is always kept higher than the ground pressure, and the lining material is placed between the formwork and the ground from the concrete piston room, and the lining material is placed in the reinforcing bar assembly room. When the pressure is equal to the pressure of the external lining material, the rear auxiliary gable frame is taken out, the lining material in the reinforcing bar assembly room and the external lining material are integrated, and the pressure holding jack is used to push out the piston in the concrete piston room. The method is characterized in that the shield machine excavates while pressing the lining material so that the pressure is higher than the earth pressure and water pressure of the ground, so the pressure can be maintained sufficiently. In addition to reliably preventing pressure drop, there is no water leakage.
This has the excellent effect of making it possible to cast high-strength, high-quality lining materials.

Moreover, in the present invention, when placing lining material and digging, the gable is pressed by the gable frame presser jack, and when assembling reinforcing bars, the gable frame supports re-receive the load applied to the gable and the gable frame is pressed down. Since the presser jack is retracted and the reinforcing bars and formwork are set, there is no need to tie the newly assembled reinforcing bars to the previous reinforcing bars, and the reinforcing bars and formwork can be temporarily assembled together outside the mine. become. Therefore, in the present invention, by installing the reinforcing bars and formwork in a factory, the construction work can be carried out in the same manner as segment assembly in ordinary shield construction, and the shield tunnel can be constructed quickly and safely. There is also the effect that it can be done.

[0094] If a formwork unit is constructed by integrally assembling reinforcing bars and flange hardware that also serves as the end frame on the outer periphery of the formwork, and the formwork is assembled using this formwork unit,
Work efficiency can be improved.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a tunnel showing a state in which a shield machine is excavating a ground.

FIG. 2 is a sectional view taken along line E in FIG. 1;

FIG. 3 is a sectional view taken along the Rolo line in FIG. 1;

FIG. 4 is a sectional view showing a state in which the propulsion jack is retracted and the gable frame is supported by the gable frame support.

FIG. 5 is a sectional view showing a shield machine being dug by a propulsion jack.

FIG. 6 is a cross-sectional view showing a state in which the reinforcing bar assembly chamber is filled with lining material.

FIG. 7 is a sectional view showing a state in which the reinforcing bar assembly chamber is filled with lining material.

FIG. 8 is a sectional view showing a state in which the end frame is pressed by the end frame presser jack and lining material is sent to the concrete piston chamber.

FIG. 9 is a sectional view showing a state in which the gable frame is supported by the gable frame presser jack and the gable frame support.

FIG. 10 is a cross-sectional view showing how the end portions of the gable frame support fit together.

FIG. 11 is a plan view showing the end frame support having a circular cross section inserted into the fitting hole of the inner cylinder.

FIG. 12 is a plan view showing a state in which the end frame support having an oval cross section is inserted into the fitting hole of the inner cylinder.

FIG. 13 is a plan view showing a state in which the end frame support having an oval cross section is inserted into the fitting hole of the inner cylinder.

FIG. 14 is a side view of a formwork unit that integrates a formwork and reinforcing bars.

FIG. 15 is a side view of a formwork unit that integrates a formwork and reinforcing bars.

FIG. 16 is a side view of a joint connecting the formwork and reinforcing bars.

FIG. 17 is a side view showing another example of the long nut of the connecting hardware.

FIG. 18 is a front view shown for explaining the divided structure of the formwork unit.

FIG. 19 is a front view shown to explain in detail the divided structure of the formwork unit.

FIG. 20 is a front view shown for explaining the joining work of formwork units.

FIG. 21 is a front view shown for explaining the joining work of formwork units.

FIG. 22 is a front view shown for explaining the joining work of formwork units.

FIG. 23 is a front view shown for explaining the joining work of formwork units.

FIG. 24 is a front view illustrating in detail a divided structure of a formwork unit with a different arrangement of reinforcing bars.

[Explanation of symbols]

T tunnel 1 Formwork 10 Shield machine 11 Skin plate 12 Cutter device 13 Propulsion jack 20 Outer cylinder 21 Inner cylinder 22 Partition wall 23 Concrete piston chamber 24 Extrusion piston 25 Pressure holding jack 50 Flange hardware that can also be used as a gable frame 51 Auxiliary wife frame 60　Gable frame presser jack 70 Support for wife frame

Claims (3)

[Claims] Claim 1: While excavating the ground using a cutter device at the tip of a shielding machine, the peripheral wall of the excavated tunnel is covered with a formwork at a predetermined interval, and reinforcing bars are placed between the formwork and the peripheral wall. A shield tunnel lining method in which the inner surface of the tunnel is lined by supplying lining material at the same time, the tail part of the skin plate of the shield machine is formed double by an outer cylinder and an inner cylinder , A plurality of partition walls extending in the radial direction of the skin plate are formed between the outer cylinder and the inner cylinder of this tail portion to provide a plurality of concrete piston chambers in which the extrusion pistons are accommodated, and reinforcing bars are placed inside the inner cylinder. At the same time, set the flange metal fitting that also serves as the end frame to close the gap between the inner cylinder and the formwork so that its outer end touches the inner surface of the inner cylinder, and connect the inner end of the flange metal fitting that also functions as the end frame and the formwork. After closing the gap between the outer surface and the outer surface by protruding the auxiliary gable from the inside of the formwork, the inner cylinder, formwork,
When placing lining material in the reinforcing bar assembly room surrounded by the gable frame and when excavating the shield machine, the gable frame is pressed with a gable frame holding jack at a pressure higher than the ground pressure inside the shield machine. On the other hand, when assembling reinforcing bars, instead of the end frame presser jack, a support for the end frame that receives the load on the formwork is protruded from inside the formwork, so that the pressure of the lining material is always lowered from the ground pressure. lining material is placed between the formwork and the ground from the concrete piston room, and the pressure of the lining material in the reinforcing bar assembly room is equal to the pressure of the external lining material. At this point, the rear auxiliary gable frame is taken out and the lining material in the reinforcing bar assembly room is integrated with the external lining material, and the pressure of the lining material is applied to the extrusion piston in the concrete piston room using a pressure holding jack. A shield tunnel lining method characterized by excavating a shield machine while applying pressure to a pressure higher than water pressure. [Claim 2] In the shield tunnel lining method according to claim 1, a formwork unit is constructed in advance by integrally assembling reinforcing bars and a flange metal fitting that also serves as an end frame on the outer periphery of the formwork, and the formwork A shield tunnel lining method characterized by assembling units. [Claim 3] In the method for lining a shield tunnel according to claim 1, a formwork unit in which reinforcing bars and a flange metal fitting that also serves as an end frame is integrally assembled on the outer periphery of the formwork is tapered in the width direction of the formwork unit. A wedge-shaped third formwork unit provided with a wedge-shaped formwork; and a second wedge-shaped formwork unit that is arranged on both sides of the wedge-shaped third formwork unit and tapered only at the joint surface with the wedge-shaped formwork. It is composed of three types of formwork units: a formwork unit and a first formwork unit that is assembled successively on the other joint surface of this second formwork unit, and the first formwork unit has its length. After connecting the second formwork unit along the direction and assembling the second formwork unit successively to the first formwork unit, the third formwork unit is finally inserted between the second formwork units, and the second formwork A shield tunnel lining method characterized by assembling it into a unit.