JP3101550B2 - Steel pipe receiving method and equipment used for the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel pipe precasting method and an apparatus used in the method, and more particularly to a steel pipe preloading method and a method as a ground pre-reinforcement method used for tunnel excavation under poor geological conditions. The present invention relates to an apparatus used for:

[0002]

2. Description of the Related Art In recent years, there has been a tendency for tunnel construction to have a large cross section, a large length, and a high speed construction, regardless of the location conditions and the ground conditions. For this reason, tunnels with considerably large excavated cross sections have been planned and constructed even under poor geological conditions. In these tunnels, a ground pre-strengthening method of reinforcing the ground in front of the tunnel face to a predetermined strength in advance is often performed as an auxiliary method. The main purpose of this type of ground reinforcement method is to suppress the advance loosening of the ground in front of the face, so the length of the pipe used for the front support is longer than that of the conventional forepiling method. It is. For this reason, various ground-leading reinforcement methods have been developed and implemented which are designed to efficiently cast long pipes.

[0003] As an example of the ground reinforcement method, there is the Trevi tube method. This Trevi tube method is long (about 11m) at a time by double pipe drilling using an expanding bit.
Pipes can be cast. Further, after drilling, the outer pipe (injection steel pipe) is left in the ground and the gap around the steel pipe is fixedly injected.

[0004] Recently, the AGF (All Ground Fasten) method has been used as a ground-level advance reinforcement method in which a steel pipe is driven into a face by a hydraulic jumbo used for tunnel excavation. In this AGF method, a steel pipe of about 3 m is mounted on the guide shell of a hydraulic jumbo used for excavation, and a hole is drilled with an enlarged bit attached to the tip of a drilling rod. A number of steel pipes are inserted while being connected. After the predetermined number of steel pipes are inserted, the bit diameter is reduced to a diameter that can be accommodated in the steel pipes, and the bit is pulled out together with the drilling rod. A cement-based or urethane-based fixing and injecting material is injected into the resulting gap between the ground and the ground to improve the ground within a predetermined range in which the steel pipe is inserted.

[0005] Fig. 18 is a schematic construction diagram showing the construction situation of the ground front reinforcement of the tunnel face by the AGF method. In this AGF method, the steel pipe 100 is cast
This is performed by a hydraulic drill jumbo 101. The steel pipe 100 is driven into the face face 103 with the lower end of the already built steel support 102 as a guide. But,
Since the steel pipe 100 to be cast is long, the pipe 100 is installed at a predetermined inclination angle with respect to the face. Normally, a steel support 102 is driven along the inclination of the steel pipe 100 with a predetermined clearance from the cross section of the tunnel 5 to 6 bases before the face. For this reason, the steel pipe 100 cast over the entire upper half has a shape in which the umbrella is slightly opened at a predetermined pitch toward the face. The feature of this construction method is that an umbrella-shaped ground improvement body is formed continuously in the longitudinal direction of the tunnel.

[0006]

In the above-mentioned Trevi tube method, a long steel pipe can be cast at one time. However, a special steel pipe setting device is required to cast a steel pipe. is necessary. For this reason, introduction of dedicated equipment,
There is a problem that ancillary work such as assembling work of the device occurs, which is expensive as an auxiliary construction method, and leads to an increase in construction cost of the entire tunnel construction.

On the other hand, in the AGF method, a hydraulic drill jumbo used for tunnel excavation is used. Therefore, such a problem can be avoided. However, a plurality of steel pipes are continuously supplied to the tip of the hydraulic drill jumbo. Much of the work to be done and the work of attaching and detaching the drill rod must be done manually.
A problem arises in that a wide range of work scaffolds must be provided near the face. In addition, this work scaffold must move frequently in view of the face excavation cycle,
The labor involved in the operation also imposes a heavy burden.

Further, as a problem common to both of the above-mentioned methods, since the mouth of the cast steel pipe and the erected position of the steel support work interfere with each other, the tunnel cross section is arranged along the arrangement of the cast steel pipe. Must be excavated in stages. For this reason, the amount of ground excavation increases, and there also arises a problem that it is necessary to adjust the dimensions of the steel support in accordance with the changed cross-sectional shape and to build the steel support. In addition, the amount of lining concrete increases, and the cross-sectional shape changes.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a steel pipe front receiving method capable of efficiently reinforcing the ground in advance of a tunnel while securing a constant tunnel cross section. It is intended to provide an apparatus using the same method.

[0010]

In order to solve the above-mentioned problems, the present invention provides a tunnel excavator equipped with a steel pipe used as a receiving steel pipe and a drilling rod housed inside the steel pipe. Then, drilling a hole capable of driving the steel pipe with a scalable bit attached to the tip of the drilling rod at predetermined intervals along the vicinity of the outer periphery of the tunnel cross section in front of the tunnel face, A plurality of steel pipes are connected and cast into the ground to form a front receiving steel pipe for the tunnel face, and the front receiving steel pipe is used as an injection pipe to inject a solidified material into the ground surrounding the front receiving steel pipe, thereby reinforcing the ground. In the steel pipe pre-receiving method, when laying the pre-received steel pipe, a buried pipe is connected to a rear end of the steel pipe, and the rear end of the steel pipe is located at an outer peripheral line position of a tunnel cross section.
The buried pipe is positioned so that
Is buried in the ground .

[0011] At this time, the buried pipe is made of a resin pipe, and the impact operation of the tunnel excavator is transmitted to the rearmost end of the steel pipe via the resin pipe, and the feed operation of the tunnel excavator is performed by the resin pipe. It is preferable that the resin pipe is transmitted to the steel pipe, and a rear end of the steel pipe is buried to a depth in the ground substantially equal to the length of the resin pipe, and the resin pipe is kept in the ground.

Further, the buried pipe is made of a steel buried pipe, and transmits a striking operation of the tunnel excavator to the rearmost end of the steel pipe through the steel buried pipe, and feeds the tunnel excavator. Is transmitted to the steel pipe, and the rear end of the steel pipe is buried to a depth in the ground substantially equal to the length of the resin pipe, and then the steel buried pipe is pulled out and collected.

In the above method, the steel pipe and the drilling rod accommodated in the steel pipe are positioned at a predetermined position by a clamp device mounted on a tip end of a guide shell of the tunnel excavator. Preferably, the end is gripped and fixed, so that the connection and disconnection of the steel pipe and the drilling rod are performed at the position of the clamping device.

That is, the end of the steel pipe mounted on the tip of the guide shell of the tunnel excavator, and the end of the drilling rod housed inside the steel pipe are gripped and fixed in a positioned state, and the steel pipe and the drill are cut. It is preferable to provide a clamp device for performing connection and separation work of the hole rod.

Further, in the method, the steel pipe and a drilling rod accommodated in the steel pipe are set on a holding part of a steel pipe supply device mounted on a side of a guide shell of the tunnel excavator. It is preferable that the steel pipe supply device be transferred to the steel pipe connection position on the guide shell from a state in which the steel pipe supply device is moved sideways.

That is, a steel pipe and a drilling rod accommodated inside the steel pipe are gripped by a side of a guide shell of a tunnel excavator, and the steel pipe is connected to a steel pipe connecting position on the guide shell by a transverse feed means. It is preferable to provide a steel pipe supply device which is adapted to be transferred to a steel pipe.

Further, the steel pipe has a plurality of strainer holes formed at predetermined intervals in a longitudinal direction and a circumferential direction, and a ring check valve is mounted so as to close the strainer holes arranged in the circumferential direction. Preferably, the ring-shaped check valve is pushed out from the inside of the pipe by the working internal pressure so that the solidified material is discharged from the strainer hole to the ground side.

Alternatively, the steel pipe has a plurality of strainer holes formed at predetermined intervals in a longitudinal direction and a circumferential direction, and a plurality of valve pieces made of a magnetic alloy are applied to the outer peripheral surface of the steel pipe so as to close the strainer holes. It is preferable that the valve piece is separated from the steel pipe by the working internal pressure by being sucked, and the solidified material is discharged from the strainer hole to the ground side.

Alternatively, the steel pipe has a plurality of strainer holes formed at predetermined intervals in a longitudinal direction and a circumferential direction, and a plurality of valve pieces are adhered to the outer peripheral surface of the steel pipe so as to close the strainer holes. Preferably, the valve piece is peeled from the steel pipe to discharge the solidified material from the strainer hole to the ground side.

That is, a ring-shaped check valve for closing the strainer holes arranged in the circumferential direction among a plurality of strainer holes formed at predetermined intervals in the longitudinal direction and the circumferential direction of the steel pipe is mounted as the valve. The ring-shaped check valve is pushed out from the inside of the pipe by the working internal pressure, and the solidified material is discharged from the strainer hole to the ground side.

Alternatively, a plurality of valve pieces made of a magnetic alloy for closing a plurality of strainer holes formed at predetermined intervals in a longitudinal direction and a circumferential direction of the steel pipe are magnetically attracted to an outer peripheral surface of the steel pipe, and the valve is operated by an internal pressure. A piece is separated from the steel pipe, and the solidified material is discharged from the strainer hole to the ground side.

Alternatively, a plurality of valve pieces are adhered to the outer peripheral surface of the steel pipe so as to close a plurality of strainer holes formed at predetermined intervals in the longitudinal direction and the circumferential direction of the steel pipe, and the valve pieces are attached to each other by an action internal pressure. The solidified material is discharged from the steel pipe to the ground side through the strainer hole.

It is preferable that the plurality of steel pipes are joined via a tapered fitting formed at a pipe end of the steel pipe.

It is preferable that the drilling rod is held at a position near the center axis of the steel pipe via a rod spacer.

[0025]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a preferred embodiment of a steel pipe receiving method according to the present invention. FIG. 1 is a construction status diagram schematically showing the excavation status of the upper half portion 1 of the tunnel cross section shown in FIG. 2 as viewed in the longitudinal direction.
As shown in FIG. 1, a crawler-type hydraulic drill jumbo J is disposed in an upper half plate near the tunnel face 2. Guide shell 4 on the boom of hydraulic drill jumbo J
Is set so as to meet the lower end position of the steel support 5A closest to the face 2 among the steel supports 5 already built. In the embodiment of the present invention, the ground is covered with primary shotcrete 6 (coating thickness t = 5 cm), and a steel support 5 made of H-section steel (H-200 × 200) is provided inside the tunnel. It is erected at a pitch of 1 m in the direction of excavation.
(Coating thickness t = 20 cm).

The installation angle of the guide shell 4 on which the steel pipe P shown in FIG. 1 is mounted is set to an inclination angle such that the guide shell 4 passes above the two steel supports 5 located in the face 2 from the erection point. Have been. In the ground in front of the face where the tip of the guide shell 4 is set, there are already four steel pipes P
Is built in the ground. As described later, the steel pipes P are connected by a hydraulic clamp device 10 mounted on the guide shell 4, and in the connected state, the steel pipes P are buried by a steel pipe buried pipe 20 (the configuration of which will be described later). It was pressed into the ground by the minute. In the present embodiment, the length of each steel pipe P and the length of the steel pipe buried pipe 20 are set to 3 m. In addition, in the ground around the already built steel pipe P, over almost the entire length of the steel pipe P, an injection zone G
Are formed.

Thus, in the tunnel shown in FIG.
The steel pipe pipe P cast before excavation of the face 2 can be expected to have a reinforcing effect as fore piling.
Further, by the ground improvement injection performed using the steel pipe P, the ground strength of the injection zone G from the top end of the tunnel to the shoulder portion is enhanced. Thereby, the tunnel deformation due to the release of the ground can be suppressed. The improved body size of the ground injection zone G by solidification material injection is assumed to be a substantially cylindrical shape having a diameter of 80 cm with the steel pipe P as the central axis. The injection zone G is formed all around the tunnel, but especially in the vicinity of the tunnel excavation line, the ground improvement body overlaps and is formed as an integral arch. This allows
The stability of the mountaintop at the top of the tunnel during tunnel excavation will be more reliable. The details of the ground injection will be described later.

Hereinafter, the configuration of each device mounted on the guide shell 4 of the hydraulic drill jumbo J for carrying out the present method will be described with reference to FIGS. 1 and 3 to 6.

As shown in FIG. 1, in order to carry out the present construction method, a hydraulic clamping device 10
A steel pipe buried pipe 20, a steel pipe pipe setting adapter 30, and a steel pipe pipe / rod supply device 40 are mounted.
Among them, the steel pipe buried pipe 20 and the steel pipe pipe setting adapter 30 that function to bury the steel pipe P will be described. FIG. 3A shows a steel pipe pipe P connected to a distal end of the steel pipe pipe setting adapter 30.
In the present embodiment, the steel pipe P has a nominal diameter of 100A.
(Outer diameter = 114.3mm) carbon steel pipe for pressure piping (J
IS symbol: STGP). A drill rod 32 is housed inside the steel pipe P.

The steel pipe pipe setting adapter 30 transmits the striking force and the rotational force from the hydraulic drifter 3 (see FIG. 1) to the drilling rod 32 and is integrated with the hydraulic drifter 3 with the feed operation of the hydraulic drifter 3. It can slide on the guide shell 4 effectively. Here, the configuration of the steel pipe pipe driving adapter 30 for driving the drilling rod 32 provided with the diameter expanding bit 31 will be described with reference to FIG.

The steel pipe pipe setting adapter 30 is mounted on the tip of the shank rod S of the hydraulic drifter 3. The steel pipe pipe setting adapter 30 has a rod support 38
And a pipe press-fitting head 33. Rod support 3
8 is a hydraulic drill (not shown) in which a drilling rod 32 for transmitting the impact and rotation of the drilling drill bit 31 at the tip of the rod is used.
To support the rod rotation. Pipe press-fit head 3
3 presses the steel pipe P into the ground by the impact and feed mechanism of the hydraulic drifter 3.

First, the configuration of the rod support 38 will be described. A hitting sleeve 34 is provided at the tip of the shank rod S.
Is screwed. An adjusting double screw rod 35 is connected to the end of the steel pipe pipe setting adapter 30 of the impact sleeve 34, and a fixed-diameter drilling rod 32 is connected via a sleeve (coupling) 36. This drill rod 3
A drill bit 31 is attached to the tip of 2. The drill bit 31 is capable of expanding and reducing the diameter.
As shown in (a), it can protrude from the tip of the steel pipe P toward the ground. That is, when the drilling rod 31 is in the normal rotation state, the drilling bit head 31a urged by the built-in spring pin (not shown) projects outward. Thus, the ground can be drilled with a drilling diameter larger than the outer diameter of the steel pipe P (φ = 121 mm in this embodiment). On the other hand, when the drilling rod 32 is in the reverse rotation state, the drilling bit head 31a can be folded to reduce the outer diameter of the bit to the inner diameter of the steel pipe (102.3 mm) or less.
Therefore, at the completion of the installation of the steel pipe P, the drill rod 3
The drill bit 31 can be collected by reversely rotating the rod 2 and pulling out the rod.

The pipe press-fitting head 33 is
4 is a member that functions as a hammer that transmits the impact force transmitted from 4 to the rear end of the steel pipe P. A continuous impact force is applied to the rear end of the pipe press-fit head 33 from an impact sleeve 34. In order to prevent the member from being deformed or worn by the impact operation, the rear end recess 33a is formed.
Inside, a buffer ring 37 is mounted. The impact from the hydraulic drifter 3 and the propulsion operation by the feed mechanism of the hydraulic drifter 3 are simultaneously transmitted to the pipe press-fit head 33 configured as described above. Thereby, the rear end of the steel pipe P is fitted to the shoulder 33d of the front end of the pipe press-fit head 33, and a dynamic hitting action and a static pushing action are applied to the inside of the hole drilled by the drill bit 31. Steel pipe P
Can be easily buried in the ground .

FIG. 3B shows a steel pipe pipe setting adapter 3.
FIG. 6 is a partial cross-sectional front view showing a steel pipe pipe buried pipe 20 attached to the pipe No. 0 and a part of the steel pipe pipe P further pushed deep into the ground by the tip of the steel pipe pipe buried pipe 20. In the first embodiment, the steel pipe buried pipe 20 is composed of a main pipe 21 having a nominal diameter of 80 A (outer diameter: 89.1 mm) and a mouth pipe 22 which receives a striking force by a steel pipe pipe setting adapter 30.
(Nominal diameter: 125A) and a series-diameter steel pipe in which a distal pipe 23 (Nominal diameter: 100A) for pressing the rear end of the steel pipe P is integrally welded and joined. Steel pipe buried pipe 20
The mouth tube 22 is loosely fitted in the small-diameter cylindrical portion 33b so that the rear end portion 22a abuts on the flange portion of the shoulder portion 33c of the steel pipe pipe setting adapter 30 during use. For this reason, the steel pipe buried pipe 20 is pushed into the ground by the impact force transmitted from the steel pipe pipe setting adapter 30 , and almost the whole
Is buried in the ground . At this time, the distal pipe 23 is a pipe having the same diameter as the steel pipe P, and a tapered joint surface is formed at the distal end of the distal pipe 23 so as to be able to contact the rear end of the steel pipe P.

In the state shown in FIG.
The Actuation, at the same time as drilling by drilling bit at the tip position of the steel pipe pipe P (not shown) is performed, an amount corresponding to steel pipe buried pipe 20 is written by pressing the earth mountains, the earth mountains A steel pipe P is pushed further into the ground . Finally, almost the entire length of the steel pipe buried pipe 20 is buried in the ground, and the rear end of the steel pipe P is pushed to the erected position side of the steel support 5. After that, by pulling out the steel pipe buried pipe 20, only the steel pipe P can be installed outside the built-in position of the steel support 5 in the ground.

FIG. 3C shows a steel pipe buried pipe 20,
This shows a second embodiment in which a vinyl chloride tube as a resin tube is used. In this embodiment, the steel pipe buried pipe 20 made of the vinyl chloride pipe is directly attached to the steel pipe pipe setting adapter 30 similarly to the steel pipe P to be cast. That is, the rear end of the PVC pipe is fitted to the tip shoulder 33d of the tip of the steel pipe pipe casting adapter 30,
As shown in FIGS. 9A and 9B, the front end is formed by a taper joint surface 71 at the rear end of the steel pipe P via a coupler 70.
Is fitted to. The vinyl chloride pipe used has a strength and rigidity capable of reliably transmitting the striking force, the rotating force, and the pushing force transmitted from the steel pipe pipe setting adapter 30 to the steel pipe pipe P. The use of this vinyl chloride pipe as the steel pipe buried pipe 20, embedded in the embedded section shown in FIG. 1
Has been a vinyl chloride tube while leaving, it is possible to terminate the droplet設作industry steel pipe P. That is, in the first embodiment, it is necessary to pull out the work of steel pipe buried pipe 20, in this embodiment, be directly leaving the <br/> PVC pipes buried in the ground Yamauchi, Since it can be easily crushed and removed by the excavating machine at the time of excavation, it is not necessary to pull out the polyvinyl chloride pipe as the steel pipe embedded pipe 20. Further, there is an advantage that there is no danger of collapse of the ground and the hole wall after the steel pipe buried pipe 20 is pulled out.

Next, the structure of the hydraulic clamp device 10 used for connecting the steel pipe P and the drilling rod 32 will be described with reference to FIGS. The ground drilling by the drilling rod 32 and the ground pressing operation of the steel pipe P are performed in parallel. For this reason, the length of the steel pipe P and the drilling rod 32 are made equal, the drilling rod 32 is accommodated in the steel pipe P, integrated, and mounted on the guide shell 4 of the hydraulic drill jumbo J to perform the work. Is efficient. in this case,
When the steel pipe P and the drilling rod 32 are set in the steel pipe pipe setting adapter 30 and drilling and press fitting are performed, connection timing occurs almost simultaneously at the tip end of the guide shell 4. Therefore, in the present invention, the hydraulic clamp device 10 shown in FIG. The hydraulic clamping device 10 includes a steel pipe P and a drilling rod 32.
Can be performed at a predetermined timing. For this reason, connection and disconnection work of the steel pipe P and the drilling rod 32 can be realized as a series of operations at one place.

FIG. 4 shows the hydraulic clamping device 10 mounted on the tip of the guide shell 4. A clamp stand 12 is provided upright on a fixed flange 11 assembled according to the guide shell 4 having a substantially V-shaped cross section. Further, jack plates 13 and 14 are fixed to front and rear positions in the longitudinal direction of the guide shell 4 with the clamp stand 11 interposed therebetween. The jack plates 13 and 14 are support plates that support and fix a group of jacks that constitute a clamp mechanism that holds the steel pipe P and the drilling rod 32.

FIG. 5A shows a sleeve clamp mechanism 1.
5 is shown. This sleeve clamp mechanism 15
This is a clamp mechanism for connecting and disconnecting the drilling rod 32 with the sleeve 8. The two hydraulic jacks 16, 16 are arranged at horizontally opposed positions around the rod arrangement position on the guide shell 4. Rod 16a of hydraulic jack 16
A chuck 17 is attached to the tip. The distal end grip portion of the chuck 17 is machined into an arc shape that matches the outer diameter of the sleeve, which is the connection position of the drilling rod 32. Thereby, the sleeve portion of the drilling rod 32 can be reliably gripped with the rod 16a extended. Also,
The chuck interval is set so that the steel pipe P can pass when the rod retracts. Since the chuck 17 is detachably attached, the chuck 17 can be easily replaced with a chuck having a tip grip portion that matches the sleeve diameter. In the present embodiment, the sleeve that connects the drilling rod 32 is gripped by the chuck, but the rod 32 near the sleeve may be gripped directly.

FIG. 5B shows a pipe clamp mechanism 18.
It is shown. The hydraulic jack 1 having the same structure as that shown in FIG.
6 and 16 are arranged, and the shape of the chuck 19 is set so as to match the outer diameter of the steel pipe P. The steel pipe P pressed into the ground by the pipe clamp mechanism 18
Can reliably grip the rear end.

FIGS. 6A and 6B show a steel pipe / rod supply device 40 for mounting the steel pipe P temporarily placed on a stock rack to the guide shell 4. A stock rack 4 is provided on the side of the guide shell 4 at a position behind the hydraulic clamping device 10 on the guide shell 4.
1 (see FIG. 6B). The rod transfer jacks 42 are mounted on the two stock racks 41 so that the cylinder rods 43 extend toward the guide shell 4.
Is equipped. At the tip of the cylinder rod 43 of the rod transfer jack 42, a steel pipe pipe holding portion 44 is formed. In the stock rack 41, steel pipes P to be built next can be stocked one by one. According to this steel pipe / rod supply device 40, when the pipe press-fit head 33 retreats on the guide shell 4 as shown in FIG. 6A, the cylinder rod 43 of the rod transfer jack 42 is extended, The steel pipe pipe P gripped by the steel pipe pipe gripper 44 can be traversed to the rod set position shown in FIG. 6B.

When the pipe press-fitting head 33 of the steel pipe pipe setting adapter 30 is advanced in a state where the steel pipe P is transferred to the rod setting position, the shoulder 33d at the tip of the small-diameter cylindrical portion 33b of the pipe press-fitting head 33 becomes The steel pipe P is fitted to the rear end of the pipe P, and can be paid out toward the face. Next, a procedure for connecting the steel pipe P and the drilling rod 32 using the hydraulic clamp device 10 will be described with reference to FIG. FIGS. 7A to 7G are state explanatory diagrams showing respective states of the connection work. FIG. 7 (a)
Shows a state where the driving of the first steel pipe P is completed. The rear end of the steel pipe P1 is gripped by a pipe clamp mechanism 18. On the other hand, the sleeve clamp mechanism 1
The rod of the hydraulic jack 16 is in a retracted state, and the chucks are separated so that the steel pipe P1 can easily pass through. From this state, the steel pipe pipe setting adapter 30 is retracted along the guide shell 4 while rotating the rotation mechanism of the hydraulic drifter (not shown) in the reverse direction, and the drilling rod is moved until the sleeve 8 comes to the position of the sleeve clamp mechanism 15. 32 is pulled out (see FIG. 7B), and the drilling rod 32 is cut off with the sleeve 8 (see FIG. 7C). Further, the steel pipe pipe setting adapter 30 is retracted along the guide shell 4 to the rear position of the stock rack 41, during which the sleeve 8 portion of the drilling rod 32 projecting from the rear end of the steel pipe P is clamped by the sleeve clamp mechanism 15 To grip. Steel pipe pipe setting adapter 30 is used as stock rack 41
The second steel pipe P2 placed on the stock rack 41 is transferred onto the guide shell 4 while retracted to the rear of the position (see FIG. 7D). At this time, the drilling rod 32 is accommodated in the steel pipe P2. At this time, the drilled rod 32 is held at a position near the center axis of the steel pipe P by an elastic rod spacer 75 (see FIG. 10) fitted near the front end and the rear end of the rod. The elastic rod spacer 75 includes the rings 76 and 3
Although it is composed of the leg portions 77, any shape may be used as long as the rod 32 can be held at the center position, and the leg length may be appropriately set according to the inner diameter of the steel pipe P. Since this elastic rod spacer 75 is mounted, the steel pipe pipe setting adapter 30 is fed to connect the drilling rod 32 for the replenishment by the rotation mechanism, and at the same time, the pipe is pressed into the rear end of the steel pipe P2. The tip shoulder 33d of the head 33
Can be fitted. Thereafter, the drilling rod 32 is screwed into the sleeve 8 held by the sleeve clamp mechanism 15 by feeding the steel pipe pipe setting adapter 30 and rotating the rod (see FIG. 7E). At the same time, the rod of the hydraulic jack 16 is retracted and the steel pipe pipe setting adapter 30 is fed to join the steel pipe pipe P2 to the steel pipe P1 held by the pipe clamp mechanism 18 (see FIG. 7 (f)). .

At this time, the inner peripheral surface of the rear end of the first steel pipe P1 is tapered (a, b, c) as shown in FIG. Taper processing (a ', b',
c ′) is given. Thus, the steel pipes P1, P2
Since a tapered joint surface of a predetermined shape is formed between them,
From the steel pipe pipe setting adapter 30 to the subsequent steel pipe P2
When a striking force is applied to the steel pipes, the tapered joint surfaces between the steel pipes P1 and P2 are securely fitted to each other, so that the steel pipes P can be quickly and easily joined to each other as compared with screw joint or the like. In this state, the pipe clamp mechanism 18 is released, and the ground drilling and pipe press-fitting operations are restarted (see FIG. 7 (g)). The rotation and impact operation of a hydraulic drifter (not shown) is transmitted to the drill bit 31 and the steel pipes P1 and P2 via the steel pipe pipe setting adapter 30.

Next, FIGS. 11 (a) to 11 (c) and FIG.
With reference to 2 (d) to 12 (f), a work flow will be described for a construction procedure of the steel pipe front receiving method of the tunnel ground according to the present invention. In each of FIGS. 11 and 12, the illustration of the existing steel pipe behind the face is omitted for simplification of the drawings.

FIG. 11 (a) shows a state where the first steel pipe P1 is placed at a predetermined position of the tunnel face 2. At the tip of the hydraulic drifter 3 mounted on the guide shell 4, a steel pipe pipe setting adapter 30 is provided. Drilling rod 3 via steel pipe pipe setting adapter 30
The blow and the rotational force from the hydraulic drifter 3 are transmitted to 2. As a result, the steel pipe pipe P1 slid on the guide shell 4 by the feed of the hydraulic drifter 3 is pushed into the ground and buried at the same time when the ground drilling is performed. In FIG. 11 (b), the first steel pipe P1 is cast in the ground in front of the face, then the hydraulic drifter 3 is retracted along the guide shell 4, and the second steel pipe P2 is cast. A state is shown in which the drilling rod 32 is set on the adapter 30 and, at the same time, the drilling rod 32 housed in the steel pipe P2 is extended via a sleeve (not shown).

FIG. 11C shows two steel pipes P
1, P2 is cast into the ground in front of the face, then the steel pipe buried pipe 20 is mounted on the guide shell 4 and the drilling rod 32 is connected. The steel pipe buried pipe 20 is used to bury the entire steel pipe P in the ground until the rear end of the steel pipe P2 already built in the ground is located outside the tunnel excavation line as described above. Attachment. The steel pipe pipe setting adapter 30 is a steel buried pipe shown in FIG. 3B, and FIG.
The steel pipe pipe P can be buried in any of the types of buried steel pipe pipe 20 of the vinyl chloride pipe shown in FIG.

FIG. 12D shows a steel pipe embedded pipe 20.
And a state where the drilling rod 32 is pulled out.
When the steel pipe P is buried using a steel buried pipe as the steel pipe buried pipe 20, the steel pipe buried pipe 20 is used.
It is necessary to pull out and collect both the drilling rod 32 and the drilling rod 32. At this time, the drill bit 31 at the tip of the drill rod 32
By rotating the drilling rod 32 counterclockwise, the bit diameter can be reduced. In this state, the hydraulic drifter 3 is retracted on the guide shell 4 and the drilling bit 31 and the drilling rod 3
2 can be integrally collected. At this time, it is preferable to insert a vinyl chloride pipe Pv or the like having a predetermined diameter as a protective pipe in order to prevent collapse of the hole wall after the steel pipe embedded pipe 20 is pulled out (see FIG. 12E).
In addition, when a vinyl chloride pipe is used as the steel pipe buried pipe 20, since the vinyl chloride pipe is left as it is in the ground, the work of collecting the buried pipe becomes unnecessary.

Thereafter, an operation of injecting the ground around the steel pipe P is performed. As an example of the injection method of the steel pipe front receiving method at the position of the tunnel face in the present invention, the entire surface injection method and the step injection method will be described respectively. First, in any of the injection methods, the mouth coking 50 is performed to prevent the solidified material at the time of injection from flowing backward from the hole 51 and preventing the hole wall from collapsing. In the present embodiment, the mouth caulking 5
Reference numeral 0 denotes a protection pipe Pv made of vinyl chloride (or a steel pipe pipe 2 such as a vinyl chloride pipe) as shown in FIG.
The method of filling the grout material into the cloth packer attached around the mouth portion of (0) is adopted.

In any injection method, the solidified material is injected using the above-mentioned steel pipe P as an injection pipe. For this reason, it is necessary to form strainers (injection holes) at predetermined intervals in advance on the surface of the steel pipe P. The distance between the strainers is as shown in FIG.
It is common that they are formed at equal intervals. However, in the whole surface injection method, a large area is injected at a time, so that the injected solidified material tends to collect near the face where the ground is loose. Therefore, in the whole injection method, FIG.
As shown in (1), the strainer 52 is formed denser as it goes deeper into the hole, and is roughened near the hole to make the permeation range of the solidified material uniform, thereby forming an injection zone G having a uniform injection diameter as a whole. It is also preferable to do so. FIG.
The numerical value shown in 4 is an exemplification, and it is preferable that the optimum value is set according to the mountainous condition. In the injection step, as shown in FIG. 13, the single packer 53 attached to the tip of the injection hose 56 is set in the hole 51, and the steel pipe P
Injection with uniform pressure over the entire length. As the solidifying material to be used, a cement-based chemical (trade name: LW) or the like is suitable. In addition, in the case of a mountain where collapse is expected, it is preferable to use a fine particle suspension type injection material or the like. A grout mixer 54 and a grout pump 55 composed of a two-liquid (liquid A and liquid B) system as shown in FIG.

On the other hand, in the step injection method shown in FIG. 15, a special valve 60 is provided in the strainer 52 formed in the steel pipe P, and the distance between the strainers 52 is 50.
cm. Here, the special valve 6
0 (a) and the operation at the time of injection are shown in FIG.
This will be described with reference to FIG. The special valve 60 has a check valve function such that the opening is released when an internal pressure is applied during injection, and the solidified material is discharged to the outside and closed against an external pressure. In this embodiment, as shown in FIG. 16A, a predetermined interval (# 50c) is set in the longitudinal direction of the outer periphery of the steel pipe P.
In the ring-shaped recess 62 formed in step m), four portions are formed at equal intervals in the circumferential direction. An annular rubber band 63 having a thickness of 1 mm is attached so as to close the opening 61, and covers the annular rubber band 63, and an outer peripheral ring plate 64 having one end 64 a welded around the steel pipe P.
Is attached. The special valve 60 configured as described above has p = 2 to 3 as shown in FIG.
When an internal pressure of kg / cm2 is applied, the solidified material acts to spread the ring-shaped rubber band 63 and the outer peripheral ring plate 64 through the opening 61, and the solidified material can be discharged to the outside at a predetermined pressure. On the other hand, for the external pressure from the ground side, p = 1
It can resist pressure of about 0kg / cm2. In addition, as the special valve, a limiter valve 80 shown in FIG. 17A can be used. FIG.
In (a), four discharge openings 81 are formed in the outer peripheral surface of the steel pipe P at equal intervals in the circumferential direction.
A flat cylindrical recess 82 is provided around the discharge opening 81. A valve piece 83 made of a permanent magnet is magnetically attracted to the cylindrical recess 82. Ferrite magnets, rare earth magnets, and the like are suitable as the permanent magnet.
Further, these valve pieces 83 may be made of a metal plate or a resin plate, and may be adhered to the bearing surface of the cylindrical recess 82 with an adhesive with a predetermined adhesive strength. In this limiter valve 80, FIG.
As shown in (b), when a predetermined internal pressure p is applied, the valve piece 83 magnetically attracted to or bonded to the steel pipe P separates or separates from the cylindrical recess 82, and the discharge opening is formed. 81 can be in the open state. Therefore, in order to open the discharge opening 81 of the valve corresponding to a predetermined internal pressure, it is preferable to appropriately set the magnetic flux density of the permanent magnet and the adhesive strength of the adhesive through experiments, analysis, and the like.

In the step injection method having such special valves 60 and 80, first, seal injection is performed before main injection. Seal injection is a preliminary injection process performed for the purpose of increasing the effect of injection into a limited range in each step in the main injection. First, the single packer 53 is inserted to the deepest part of the steel pipe P, and the clearance between the steel pipe P and the ground is filled and sealed in advance. Then, as the main injection, the single packer 53 is retreated from the deepest portion as one step 1 m, and injection within a limited range is repeated up to the hole 51. As the solidifying material to be used, in the present injection, in the case of sandy ground or the like, an organic loosening solution type injection material is preferable. In addition, it is preferable to use an organic flash solution type injection material for seal injection.

In each of the injection methods, FIG.
As shown in (f), an injection zone having an injection diameter of about 80 cm is formed around the pipe over the entire length of the steel pipe P that is cast from the top of the tunnel to the shoulder. Particularly, in the vicinity of the tunnel excavation line, the distance between adjacent steel pipes P is about 60 cm, so that an arch-shaped ground reinforcement area can be formed around the tunnel excavation portion (see FIG. 2). Thereby, the surrounding ground at the time of excavation can be effectively protected.

[0053]

As is apparent from the above description, according to the present invention, the rear end of the front receiving steel pipe is set in the ground by a predetermined burial amount, and the space for the support work can be secured without widening the tunnel section. In addition, it is possible to set a heavy weight receiving steel pipe on the guide shell of the tunnel excavator without human intervention and to connect steel pipes to reduce the labor of workers and save labor. It has the effect of being able to. In addition, there is an effect that the ground injection operation can be efficiently and reliably advanced by using the front receiving steel pipe.

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional view showing an embodiment of a steel pipe front receiving method according to the present invention.

FIG. 2 is a cross-sectional view showing a state in which the tunnel face shown in FIG.

FIG. 3 is a partially exploded front view showing an embodiment of a steel pipe pipe and a buried pipe embedding apparatus.

FIG. 4 is a schematic side view showing one embodiment of a hydraulic clamping device used in the present invention.

FIG. 5 is an end view of the hydraulic clamping device shown along the end line shown in FIG. 4;

FIG. 6 is a schematic plan view of a steel pipe / drilling rod supply device used in the present invention.

FIG. 7 is a work flowchart showing a connection work procedure of a steel pipe and a drilled rod by a hydraulic clamp device.

FIG. 8 is a partially enlarged sectional view showing an example of a tapered joining surface of a steel pipe.

FIG. 9 is a partially enlarged sectional view showing an example of a joint between a steel pipe and a vinyl chloride pipe.

FIG. 10 is a schematic perspective view showing an elastic rod spacer that supports a drilled rod accommodated in a steel pipe.

FIG. 11 is a state explanatory view showing the state of each construction stage of the steel pipe front receiving method (part 1).

FIG. 12 is a state explanatory view showing the state of each construction stage of the steel pipe front receiving method (part 2).

FIG. 13 is a state explanatory view showing an example of an injection state and a zone in the whole-surface injection method in the ground injection step.

FIG. 14 is a front view showing an example of a strainer formed on a steel pipe.

FIG. 15 is a state explanatory view showing an example of an injection state in the step injection method.

FIG. 16 is a partial cross-sectional view showing details of a special valve formed on the strainer.

FIG. 17 is a partial cross-sectional view showing details of a special valve formed on a strainer.

FIG. 18 is a schematic diagram showing an example of a conventional steel pipe tip receiving method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper half part of tunnel 2 Tunnel face 3 Hydraulic drifter 4 Guide shell 5 Steel support 10 Hydraulic clamp device 15 Sleeve clamp mechanism 16 Hydraulic jack 17, 19 Chuck 18 Pipe clamp mechanism 20 Steel pipe buried pipe 30 Steel pipe pipe casting adapter 31 Drilling bit 32 Drilling rod 33 Pipe press-fitting head 40 Steel pipe / rod supply device 50 Caulking at mouth 52 Strainer 53 Single packer 60,80 Valve 75 Rod spacer G Injection zone J Hydraulic drill jumbo P Steel pipe

────────────────────────────────────────────────── (5) Continuation of the front page (56) References JP-A-6-50086 (JP, A) Jiko 58-17886 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) E21D 9/04 E21D 20/00

Claims (15)

(57) [Claims] 1. A tunnel excavator equipped with a steel pipe used as a pre-received steel pipe and a drilling rod housed inside the steel pipe, and a hole in which the steel pipe can be cast is formed in a tunnel section in front of a tunnel face. The tunnel face is drilled with a scalable bit attached to the end of the drilling rod at predetermined intervals along the vicinity of the outer peripheral line, connecting a plurality of the steel pipes and driving the steel pipe into the ground. In the steel pipe head receiving method of injecting solidification material into the ground around the head steel pipe using the head steel pipe as an injection pipe and reinforcing the ground, the casting of the head steel pipe is performed. A buried pipe is connected to the rear end of the steel pipe, and the rear end of the steel pipe is an outer peripheral line of a tunnel section.
So that it is located at a depth within the ground that substantially matches the position
A steel pipe front receiving method characterized by burying a buried pipe in the ground . 2. The buried pipe is made of a resin pipe, and transmits a striking operation of the tunnel excavator to a rearmost end of the steel pipe via the resin pipe, and controls a feed operation of the tunnel excavator through the resin pipe. Transmitting to the steel pipe, burying the rear end of the steel pipe to a depth in the ground substantially equal to the length of the resin pipe,
2. The method according to claim 1, wherein the resin pipe is left. 3. The buried pipe is made of a steel buried pipe, and transmits a striking operation of the tunnel excavator to a rearmost end of the steel pipe through the steel buried pipe, and feeds the tunnel excavator. The steel pipe is buried to a depth in the ground substantially equal to the length of the resin pipe, and then the steel buried pipe is pulled out and collected. 1. The method for receiving steel pipes according to 1 above. 4. A resin pipe for transmitting a striking operation of a tunnel excavator to a rearmost end of a receiving steel pipe, transmitting a feed operation of the tunnel excavator to the steel pipe, and burying the steel pipe to a predetermined depth in the ground. A buried pipe characterized by comprising: 5. The steel pipe and a drilling rod housed inside the steel pipe are positioned at predetermined positions by a clamp device mounted on a tip end of a guide shell of the tunnel excavator, and the end of the steel pipe is drilled. The steel pipe front receiving method according to claim 1, wherein the steel pipe and the drilling rod are connected and separated at the position of the clamp device. 6. A steel pipe and a drilling machine mounted on a tip of a guide shell of a tunnel excavator and gripping and fixing an end of a steel pipe and an end of a drilling rod accommodated in the steel pipe in a positioned state. A clamp device for connecting and separating hole rods. 7. The steel pipe and the drilling rod accommodated in the steel pipe are mounted on a side of a guide shell of the tunnel excavator from a state where the steel pipe is set in a gripping part of a steel pipe supply device. 2. The method according to claim 1, wherein the steel pipe feeding device is moved to a steel pipe connection position on the guide shell by a lateral feed operation. 8. A steel pipe and a drilling rod housed inside the steel pipe, which are mounted on a side of a guide shell of a tunnel excavator, and the steel pipe is connected to a steel pipe connecting position on the guide shell by traversing means. A steel pipe supply device characterized by being transferred to a steel pipe. 9. The steel pipe has a plurality of strainer holes formed at predetermined intervals in a longitudinal direction and a circumferential direction, and a ring check valve is mounted so as to close the strainer holes arranged in the circumferential direction. 2. The method according to claim 1, wherein the ring-shaped check valve is pushed out from the inside of the pipe by an action internal pressure to discharge the solidified material to the ground side from the strainer hole. 10. The steel pipe has a plurality of strainer holes formed at predetermined intervals in a longitudinal direction and a circumferential direction, and a plurality of valve pieces made of a magnetic alloy are applied to the outer peripheral surface of the steel pipe so as to close the strainer holes. 2. The method according to claim 1, wherein the valve piece is separated from the steel pipe by an applied internal pressure and the solidified material is discharged from the strainer hole to the ground side. 11. The steel pipe has a plurality of strainer holes formed at predetermined intervals in a longitudinal direction and a circumferential direction, and a plurality of valve pieces are bonded to an outer peripheral surface of the steel pipe so as to close the strainer holes. 2. The method according to claim 1, wherein the valve piece is peeled off from the steel pipe to discharge the solidified material to the ground side from the strainer hole. 12. A plurality of valve pieces made of a magnet alloy for closing a plurality of strainer holes formed at predetermined intervals in a longitudinal direction and a circumferential direction of the steel pipe are magnetically attracted to an outer peripheral surface of the steel pipe, and the valve is operated by an internal pressure. A valve, wherein a piece is separated from the steel pipe and the solidified material is discharged from the strainer hole to the ground side. 13. A plurality of valve pieces are adhered to an outer peripheral surface of the steel pipe so as to close a plurality of strainer holes formed at predetermined intervals in a longitudinal direction and a circumferential direction of the steel pipe. A valve, wherein the solidified material is discharged from the steel pipe to the ground side through the strainer hole. 14. The method according to claim 1, wherein the plurality of steel pipes are joined via a tapered fitting portion formed at a pipe end of the steel pipe. 15. The method according to claim 5, wherein said drilling rod is held at a position near a central axis of said steel pipe via a rod spacer.