JP2002213195A - Tunnel constructing method and shield excavator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tunnel constructing method which prevents lining concrete from flowing even to a front side of a shield excavator through a cavity defined between an upper surface of the shield excavator and the natural ground, if the cavity is formed, and to provide a shield excavator for use in the method. SOLUTION: According to the tunnel constructing method, an internal form 5 is assembled at a rear location of the shield excavator 1 along an internal surface of a pit, and while concrete is placed in the internal form to form a lining wall 4 in the internal surface of the pit, the shield excavator 1 carries out driving. Then, a recess 11 is formed in a top portion of a skin plate 2 of the shield excavator 1 in a manner extending in a circumferential direction. Further, a hardener is poured into the recess 11, and then the hardened hardener H is outward squeezed from the recess 11, followed by sealing the cavity S between the upper surface of the skin plate 2 and the natural ground. While carrying out these operations, the shield excavator continuously carries out driving.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel construction method called an ECL method and a shield excavator used directly when the construction method is carried out.

[0002]

2. Description of the Related Art As is well known, the ECL method (Extruded C
The oncrete linging method) is a tunnel construction in which an inner formwork is assembled along the mine behind a shield excavator and concrete is cast almost continuously at the site to form a lining wall and excavate. Is the way.

FIG. 9 shows an example of a conventional general ECL method. In the figure, reference numeral 1 denotes a shield excavator, which is provided with a cutter 3 at a front portion of a skin plate 2 and takes a reaction force from a series of inner molds 5 to form a lining wall 4 so that the entire shield excavator 1 is provided. Is provided with a jack 6 for excavating.

The inner formwork 5 is a cylindrical divided body which is curved in accordance with the cross-sectional shape of the tunnel to be constructed and has a length corresponding to the excavation stroke of the shield excavator 1. And an assembling into a cylindrical shape as a whole, and attaching a wife formwork 7 at the forefront thereof to form an annular concrete casting space for constructing the lining wall 4.

[0005] Reference numeral 8 denotes a pressurizing piston which also serves as a wife formwork, which is pressed by a wife form jack 9 toward a casting space. An installation port to which the installation pipe 10 is connected is provided so that concrete can be installed while the pressurized state is maintained by the pressurizing piston 8.

In the ECL method using the shield excavator 1, the inner formwork 5 for one ring is assembled at the tail part of the shield excavator 1, and the lining concrete is inserted from the pressurizing piston 8 into the installation space through the installation pipe 10. C is cast, and the lining concrete C is pressurized by the pressurizing piston 8 to maintain the setting pressure higher than the groundwater pressure, whereby the lining wall 4 having excellent water stopping property can be formed. Then, before the poured lining concrete C hardens, the shield excavator 1 is dug by the propulsion jack 6 by taking a reaction force from the series of inner mold frames 5, and the inner mold for one new ring is formed behind the excavating machine. By immediately assembling the frame 5 and immediately placing the next lining concrete, the entire front and back lining concrete C is uniformly pressed by the pressing piston 8 to be surely integrated. Can be formed substantially continuously, and a joint surface (cold joint) does not occur.

[0007]

By the way, in the tunnel construction method by the above-mentioned conventional ECL method, the lining wall 4 is not used.
In order to obtain the required strength, the lining concrete C constituting the above must be kept in a high-quality concrete in which a predetermined thickness is ensured and soil, groundwater, muddy water and the like are not mixed. For this reason, as described above, while measuring the pressure of the lining concrete C being cast, it is controlled by the end form jack 9 so as to maintain a predetermined pressure.
We manage concrete placement.

On the other hand, the excavation by the shield excavator 1 is caused by the fact that the outer diameter of the excavation pit is slightly larger (about 30 to 50 mm in diameter) than the outer diameter of the shield excavator 1 and the ground collapse due to excavation. In some cases, a gap S may be generated between the upper surface of the shield excavator and the ground. In this case, as shown in FIG. 10, the lining concrete C, which is press-fitted at the tail of the shield excavator, may reach the front surface of the shield excavator 1 through the gap S. When the lining concrete C goes around the front surface of the shield excavator, the concrete material is lost, and the excavation by the shield excavator 1 is hindered, and the excavation may be stopped. Once the excavation is stopped, the wife formwork 7 cannot be moved until the concrete is hardened, so that it takes time to resume the excavation, and the construction efficiency is reduced.

As a countermeasure for the case where the lining concrete C wraps around the front of the shield excavator 1, it is conceivable to inject a backfill injection material or the like from inside the shield excavator 1, but the injected material is shielded excavation. Attached to the perimeter of the excavator, it becomes a resistance to the propulsion of the shield excavator. If the injection pressure is high, there is a drawback that it may flow into the lining concrete C and affect the quality of the concrete. It is not a complete measure.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a lining concrete through a gap even if a gap is formed between the upper surface of the shield excavator and the ground. Does not go to the front of the shield excavator, holds down the loss of concrete material, and
An object of the present invention is to provide a tunnel construction method capable of performing tunnel excavation with high construction efficiency and a shield excavator directly used for performing the construction method.

[0011]

According to the first aspect of the present invention, an inner formwork is assembled along the inner surface of a mine behind a shield excavator, and concrete is poured into the inner formwork. In the tunnel construction method of digging while forming a lining wall on the inner surface of a mine by installing, a concave portion is provided at the top of the skin plate of the shield excavator so as to extend in the circumferential direction, and a hardening material is injected into the concave portion Then, the hardened material is extruded outward from the concave portion, and the shield excavator is excavated while sealing the gap between the upper surface of the skin plate and the ground.

[0012] In the invention according to claim 2, a concave portion is provided at the top of the skin plate so as to extend in the circumferential direction.
A curing material injection mechanism for injecting the curing material into the recess and a curing material pushing mechanism for pushing the curing material cured in the recess outward.

[0013] The invention according to claim 3 is characterized in that a bag is provided in the recess, and a hardening material is injected into the bag from the hardening material injection mechanism.

According to a fourth aspect of the present invention, the hardening material extruding mechanism includes a bottom plate provided at the bottom of the concave portion and an extrusion jack for pushing the bottom plate outward.

According to the present invention, the hardened hardened material is pushed outward from the concave portion provided at the top of the skin plate, and the shield excavator is excavated while sealing the gap between the upper surface of the skin plate and the ground. Therefore, it is possible to prevent the lining concrete pressed and cast at the tail portion of the shield excavator from going around the gap between the upper surface of the shield excavator and the ground to reach the front surface of the shield excavator.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. Note that, regarding the components of the shield excavator according to the present invention, the same components as those of the shield excavator described in the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 1, the skin plate 2
It consists of a front trunk 2a, a middle trunk 2b and a rear trunk 2c, but extends between the front trunk 2a or the middle trunk 2b or between the front trunk 2a and the middle trunk 2b and at the apex thereof in the circumferential direction. Recess 11 is provided as described above. As shown in FIG. 4, the angle θ at which the concave portion 11 is provided is sufficient as long as it can close the gap S between the upper surface of the shield excavator and the ground, which is caused by collapse of the ground due to excavation. .

The recess 11 comprises an injection box 12 which also serves to reinforce the skin plate 2 as shown in FIG. The injection box 12 is composed of left and right arc-shaped side plates 12a and a bottom plate 12b, and has an upper opening. Injection box 1
2, a hardening material injection mechanism 13 for injecting a hardening material into the inside is connected. The hardening material injection mechanism 13 includes, for example, a hardening material injection pipe 13b in which a valve 13a is interposed,
It comprises a hardening material supply means 13c connected to the base end side of the hardening material injection pipe 13b (see FIGS. 2, 3, and 5). A plurality (three in FIG. 5) of hardening material injection pipes 13b are provided along the injection box 12 at predetermined intervals in the length direction thereof.
Is provided. In addition, if necessary, the hardening material injection pipe 1
A switching valve 13d for selectively connecting the curing material supply means 13c to one of the plurality of curing material injection pipes 13b may be provided between the curing material supply means 13c and the curing material supply means 13c. Since the hardening material injected into the injection box 12 only needs to function as a sealing material, it is not necessarily required to have a very high strength. It is sufficient if the hardening material has the strength of a general backfill injection material. The material is appropriately selected in consideration of this.

When the hardening material is injected into the injection box 12, first, the hardening material is injected into the lowermost injection box 12 so that the injected hardening material does not flow downward from the injection box 12 having an upper opening. The hardening material is injected, the hardening material is injected into the injection box 12 located slightly above the hardened material before the injected hardened material is completely solidified, and this operation is sequentially repeated to finally set the uppermost injection box. The injection of the hardening material may be performed while shifting the time so that the hardening material is injected into the inside 12. In addition, by using a hardening material having a viscosity as high as possible, the outflow of the hardening material may be prevented. Further, a lid (not shown) that can be opened and closed is provided in the injection box 12, The outflow of the hardening material may be prevented.

The injection box 12 is provided with a hardening material extruding mechanism 14 for extruding the hardening material H hardened in the injection box 12 to the outside. The hardening material extruding mechanism 14 includes an arc-shaped bottom plate 14a provided at the bottom of the recess 11, more specifically, at the bottom of the injection box 12, and an extrusion jack 14b for pushing the bottom plate 14a outward. I have. The extrusion jack 14b is not limited to one, and a plurality of extrusion jacks may be provided along the circumferential direction of the skin plate as needed. In addition, reference numeral 15 in FIG. 1 denotes a demolding device for removing the inner formwork provided at the rear of the shield excavator 1, 16 denotes a feeder device for sending the removed inner formwork forward, and 17 denotes a feeder device for feeding the removed inner formwork. The erector reassembling the obtained inner formwork at the tail of the seal excavator 1 is shown.

Next, a method of constructing a tunnel using the shield excavator having the above configuration will be described. The cutting face is excavated by the cutter 3 provided at the front part of the shield excavator 1, and the inner form 5 is assembled along the inner surface of the mine by the erector 17 behind the shield excavator 1, and concrete is provided in the inner form 5. The digging is performed while forming the lining wall 4 on the inner surface of the mine by casting. At this time, the hardening material is injected into the injection box 12 by the hardening material injection mechanism 13 in advance. (See FIG. 2).

When excavating with the seal excavator 1, the gap S between the upper surface of the shield excavator 1 and the ground is generated due to collapse of the ground due to excavation, and the like.
When a phenomenon is seen in which the lining concrete C, which is pressure-poured at the tail portion of the shield excavator 1 through the gap S, reaches the front of the shield excavator, the concrete C hardens in the injection box 12. The hardening material H that has been
To push it upward (see FIGS. 3 and 6). That is, the extruder jack 14b is operated to move the bottom plate 1
The hardening material H hardened in the injection box 12 is pushed upward through 4a. The hardened material H extruded upward blocks the gap S generated between the upper surface of the shield excavator 1 and the ground in the front-rear direction, and is pressed and driven at the tail of the shield excavator 1. The lining concrete C can be prevented from reaching the front of the shield excavator.

As a result, the loss of the concrete material can be suppressed as much as possible, and the situation where the lining concrete C reaches the front of the shield excavator and stops the excavation once can be avoided. Good tunnel excavation can be performed.

When the shield excavator 1 excavates,
This is performed while the hardening material H is pressed against the upper ground. At this time, a shearing force acts on the hardening material H, and the hardening material H is divided. This divided hardened material is used as is in the shield excavator 1
And the remaining hardened material H blocks the gap S in the front-rear direction, so even in this case, the lining concrete pressed and cast at the tail portion of the shield excavator 1 is also used. C can be prevented from reaching the front of the shield excavator.

A hardening material discharge port is provided at a predetermined location on the top of the skin plate 2 without providing the concave portion 11 on the skin plate 2, and the hardening material is supplied from the discharge port between the upper surface of the shield excavator 1 and the ground. There is also a method of filling the gaps S between them, but in this case, the use amount of the hardening material increases and the material loss increases, and a hardening material continuous in the circumferential direction cannot be obtained, and a complete seal cannot be expected. And the like.

On the other hand, in the present invention, the skin plate 2 is provided with a recess 11 extending in the circumferential direction, a hardening material is poured into the recess 11 once and hardened, and the hardened material is brought into contact with the upper surface of the shield excavator 1. Interposed between the ground and
Since it is used as a sealing material, material loss can be minimized, and in addition, the lining concrete C, which is pressed and cast at the tail of the shield excavator 1, wraps around the front of the shield excavator. Can be prevented.

FIGS. 7 and 8 show another embodiment of the present invention. This embodiment is different from the above-described embodiment shown in FIGS. 1 to 6 in that a bag 20 is provided in an injection box 12 and a hardening material injection mechanism (not shown) is provided in the bag 20. Is to be injected.

That is, when excavating by the seal excavator, the ground S collapses due to the excavation, etc., so that an unnecessary gap S is generated between the upper surface of the shield excavator 1 and the ground, and the gap S passes through the gap S. Then, when the phenomenon that the lining concrete C pressed and poured at the tail portion of the shield excavator 1 wraps around to the front surface of the shield excavator is observed, first, the extrusion jack 14b preliminarily enters the injection box 12 into the injection box 12. Bottom plate 14a from which folded bag body 20 is lifted
Is pushed out of the injection box 12. Thereafter, a hardening material is injected into the extruded bag body 20 from a hardening material injection mechanism, and the bag body 20 expands. This bulged bag body 20
The gap S generated between the upper surface of the shield excavator 1 and the ground is blocked in the front-rear direction (see FIG. 8), and the lining concrete C that is pressed and cast at the tail of the shield excavator 1 is formed. It is possible to prevent sneaking into the front of the shield excavator.

As described above, the bag body 20 is preliminarily arranged, and the hardening material is injected into the bag body 20 from the hardening material injection mechanism. Can be injected into the gap S between the upper surface of the ground and the ground, and a situation in which the hardening material leaks from the injection box 12 and flows out into the shield excavator to harden can be avoided. Material can be supplied.

The embodiments of the invention described above are merely examples of the invention of the present application, and the design can be changed as needed without departing from the gist of the invention. For example, in the embodiment of the invention described above, only one concave portion 11 extending in the circumferential direction is provided at the top of the skin plate 2. However, the present invention is not limited to this.
A plurality of recesses 11 are provided at appropriate intervals in the axial direction, and a hardening material is injected into each of the plurality of recesses 11, and the hardening material H hardened here is extruded outward by a hardening material extruding mechanism 14. Is also good. In this way, by arranging the hardening material H in a plurality of rows, it is possible to further prevent the lining concrete C, which is pressure-cast at the tail portion of the shield excavator 1, from reaching the front surface of the shield excavator. .

[0031]

According to the first aspect of the present invention, the hardened hardened material is pushed outward from the concave portion provided at the top of the skin plate to seal the gap between the upper surface of the skin plate and the ground. As the shield excavator is excavated, the lining concrete pressed at the tail of the shield excavator goes around the gap between the upper surface of the shield excavator and the ground and reaches the front of the shield excavator. And prevent concrete material loss,
In addition, tunnel excavation with high construction efficiency can be performed. Also, since the hardening material is injected into the recess and hardened, a hardening material having a desired shape can be easily obtained. Further, unlike a general injection method, there is no problem that the shield excavator is restrained by the hardened material and the jack thrust is increased. further,
Since the hardened material is extruded and sealed as described above, the hardened material before hardening is not mixed with a large amount of the hardened material before hardening, so that good quality concrete can be held. According to the second aspect of the invention, the same effects as those of the first aspect of the invention can be obtained. According to the third aspect of the present invention, since the bag is provided in the recess and the hardening material is injected into the bag, a situation in which the hardening material leaks from the recess and flows into the shield excavator to be hardened is avoided. Can,
In addition, there is an effect that a hardening material can be supplied at a high pressure. According to the invention according to claim 4, since the hardening material extruding mechanism is constituted by the bottom plate provided at the bottom of the concave portion and the extrusion jack for pushing the bottom plate outward, the position of the bottom is adjusted. Thus, it is possible to obtain a solidified hardened material of an arbitrary size, and to achieve effects such as being able to cope with the size of the gap between the shield excavator and the ground.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a shield excavator according to the present invention.

FIG. 2 is an enlarged sectional view showing a main part of the shield excavator.

FIG. 3 is a cross-sectional view illustrating a tunnel construction method using the shield excavator.

FIG. 4 is a sectional view of the vibration isolator.

FIG. 5 is a sectional view of the skin plate showing a position of a concave portion of the shield excavator.

FIG. 6 is a plan view showing a relationship between an injection box and a hardening material injection mechanism of the shield excavator.

FIG. 7 is an enlarged sectional view showing a main part of another embodiment of the shield excavator.

FIG. 8 is a sectional view illustrating a tunnel construction method using another embodiment of the shield excavator.

FIG. 9 is a cross-sectional view illustrating a tunnel construction method using a conventional shield excavator.

FIG. 10 is a partial cross-sectional view illustrating the tunnel construction method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shield excavator 2 Skin plate 3 Cutter 4 Lining wall 5 Inner form 7 Wife form 8 Pressurized piston 10 Concrete casting pipe 11 Depression 12 Injection box 12a Arc side plate 12b Bottom plate 13 Hardening material injection mechanism 13a Valve 13b Hardening Material injection pipe 13c Hardening material supply means 14 Hardening material extrusion mechanism 14a Bottom plate 14b Extrusion jack 20 Bag body

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Maho Watanabe 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation (72) Inventor Kazuo Miyazawa 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation (72) Inventor Shinichi Nishimura 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation F-term (reference) 2D054 AC02 AD19 AD22 2D055 BA01 BB01 CA01 DA01 DA03 JA06 LA14

Claims (4)

[Claims] 1. An inner formwork is assembled along the inner surface of a mine behind a shield excavator, and concrete is poured into the inner formwork to excavate while forming a lining wall on the inner surface of the mine. In the tunnel construction method, a concave portion is provided at the top of the skin plate of the shield excavator so as to extend in the circumferential direction, a hardening material is injected into the concave portion, and the hardened hardened material is extruded outward from the concave portion to form an upper surface of the skin plate. A tunnel construction method characterized by excavating a shield excavator while sealing a gap between the tunnel and the ground. 2. A recess provided in the top of the skin plate so as to extend in the circumferential direction, a hardening material injection mechanism for injecting a hardening material into the recess, and a hardening material hardened in the recess is pushed outward. A shield excavator comprising a hardening material extruding mechanism. 3. The shield excavator according to claim 2, wherein a bag body is provided in the recess, and a hardening material is injected from the hardening material injection mechanism into the bag body. 4. The shield excavator according to claim 2, wherein the hardening material extruding mechanism comprises a bottom plate provided at the bottom of the concave portion and an extrusion jack for pushing the bottom plate outward. .