JP4032059B2 - Double pipe double packer method - Google Patents

Description

  The present invention inserts a hollow injection pipe formed with an ejection hole into a hollow sleeve pipe installed in a natural ground and formed with a discharge hole, and supplies an injection material from the rear end of the injection pipe. The present invention relates to a double-pipe double packer method for injecting the injection material into the natural ground through the ejection holes and the discharge holes.

Conventionally, drilling of natural ground in the double pipe double packer method has been performed by double pipe excavation. In this double pipe excavation, first, the rear end of the casing and the inner rod is connected to the swivel of the double pipe excavator, the cutting water is ejected from the tip of the inner rod, and the muddy water is discharged from the gap between the casing and the inner rod. The hole is drilled by transmitting the striking force and the rotational force of the double pipe excavator to the casing and the bit at the tip of the inner rod while draining. After that, the inner rod is pulled out and a hollow sleeve pipe is built in the casing, then the casing is pulled out, and a hollow injection pipe having an ejection hole is inserted into the sleeve pipe to inject the injection material into the ground. Is. Therefore, the swivel of the double-pipe excavator can transmit the striking force and the rotational force to the casing and the inner rod and pull out each, and the cutting water and the muddy water flow path, and these cutting water and muddy water do not leak. Thus, it is necessary to have a packer function (see Patent Document 1).
JP 2002-021461 A

  On the other hand, in a tunnel excavation site by a NATM (New Australian Tunneling Method) or TBM (Tunnel Boring Machine) method, a double-pipe excavator is not always provided, and a single-pipe excavator is often provided. However, since this single pipe excavator is not provided with a swivel, even if the casing is driven into the natural ground together with the inner rod, the casing cannot be pulled out from the natural ground. Therefore, in order to adopt the double pipe double packer construction method at these sites, it is necessary to prepare a double pipe excavator, and it takes time to prepare this double pipe excavator and transport it to the tunnel excavation site, There was a problem that the construction period was prolonged.

  An object of the present invention is to perform a double pipe double packer method without delaying the construction period.

In order to solve the above-mentioned problems, the invention described in claim 1 includes, as shown in FIGS. 1 and 2, for example, a casing 1 in which a plurality of injection holes 1a are provided in a peripheral wall and a ring bit 1b is attached to the tip. Inserting an inner rod 2 to which a drilling bit 2a for transmitting a striking force and a rotational force received from a single-pipe excavator (not shown) capable of single-pipe excavation is transmitted to the ring bit 1b;
After drilling holes in the natural ground G by the inner rod 2 connected to the single pipe excavator and the casing 1, and pulling out the inner rod 2 and the excavation bit 2a from the casing 1,
A pipe (for example, a sleeve pipe 3) in which a discharge hole 3a is formed is inserted into the casing 1, and at the tip end of the pipe (for example, the sleeve pipe 3), the pipe 1 (for example, the sleeve pipe 3) is opened to the outside in the radial direction. A plurality of wing members 3c that come into contact with the casing 1 are arranged at the center of the casing 1, and a gap between the casing 1 and the pipe (for example, the sleeve pipe 3) is filled with a sealing material 6;
In the pipe (for example, the sleeve pipe 3), a pair of packers 4b and 4b separating a space in the pipe (for example, the sleeve pipe 3), and an ejection hole 4a provided between the packers 4b and 4b, Insert an injection pipe 4 comprising
In a state where the casing 1 is installed in the natural ground G, the injection material 5 is supplied from the rear end of the injection pipe 4, and the injection material 5 is supplied from the injection hole 1a through the ejection hole 4a and the discharge hole 3a. Injected into the ground,
After the injection pipe 4 is pulled out, the casing 1 and the pipe (for example, the sleeve pipe 3) are left in the natural ground G.

  According to the first aspect of the present invention, when the inner rod is connected to the single pipe excavator to give a striking force and a rotational force, the striking force and the rotational force are applied to the excavation bit attached to the tip of the inner rod. To the ring bit attached to the casing. Therefore, a single pipe excavator can be used to drill holes in the natural ground by the casing and the inner rod inserted into the casing. After drilling, the inner rod is pulled out, the pipe is inserted into the casing, the gap between the casing and the pipe is filled with a sealing material, the injection pipe is inserted into the pipe, and the injection material is injected from the rear end of the injection pipe. Supply. Thereby, the injection material is filled into the space formed by the pipe and the pair of packers through the injection hole of the injection pipe. After that, the injection material flows through the seal hole filled in the gap between the casing and the pipe through the discharge hole of the pipe, and is injected into the natural ground through the injection hole of the casing to reinforce the natural ground. . Therefore, since the work of pulling out the casing can be omitted, the double pipe double packer method can be performed by the single pipe excavator even in a site where there is no double pipe excavator. There is no need to carry it, and the construction period can be prevented from being delayed. Moreover, since a casing is left in a natural ground even after inject | pouring an injection material into a natural ground, a deformation | transformation of a natural ground can be suppressed with a casing.

  The invention according to claim 2 is the double pipe double packer method according to claim 1, wherein the single pipe excavator is an advanced boring machine for geological exploration.

  According to the second aspect of the present invention, since the single pipe excavator is an advanced boring machine for geological exploration, it is possible to reliably drill holes in the natural ground by the casing and the inner rod.

  The invention described in claim 3 is the double pipe double packer method according to claim 1, wherein the single pipe excavator is a drill jumbo.

  According to the third aspect of the present invention, since the single-pipe excavator is a drill jumbo, a drill hole can be reliably drilled in the natural ground by the casing and the inner rod, and the drill jumbo includes a plurality of drifters. Therefore, a plurality of drilling holes can be performed at the same time.

  According to the present invention, since the operation of pulling out the casing can be omitted, the double-pipe double packer method can be performed by the single-pipe excavator even in a site where there is no double-pipe excavator. It is not necessary to prepare and transport the machine, and the construction period can be prevented from being delayed. Moreover, since a casing is left in a natural ground even after inject | pouring an injection material into a natural ground, a deformation | transformation of a natural ground can be suppressed with a casing.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a case where a casing 1 is installed in a natural ground G in order to reinforce the natural ground G in the excavation direction by a double pipe double packer construction method at a tunnel excavation site by the TBM method. FIG. 2 shows drilling by the casing 1 and the inner rod 2. FIG. 3 shows the construction procedure of the double pipe double packer method.

  As shown in FIGS. 1 and 2, a plurality of injection holes 1 a are provided in the peripheral wall of the casing 1 installed in the natural ground G. The casing 1 has a ring bit 1b joined to the tip, and the inner rod 2 having a drilling bit 2a for transmitting a striking force and a rotational force to the ring bit 1b is inserted into the casing 1 with a drilling hole. I do.

  A hollow sleeve pipe 3 is inserted into the casing 1. A cylindrical rubber sleeve 3b is fitted into the sleeve pipe 3 at a predetermined interval, and minute discharge holes 3a as flow paths for the injection material 5 are formed in the sleeve pipe 3 and the sleeve 3b. ing. By applying pressure to the injection material 5 inside the sleeve pipe 3, the injection material 5 pushes and widens the discharge hole 3a and jets out of the sleeve pipe 3 vigorously. Further, a plurality of rod-shaped wing members 3 c that are opened outward in the radial direction are provided at the tip of the sleeve pipe 3. The wing member 3 c has a tip abutting against the inner wall of the casing 1, and is for placing the sleeve pipe 3 at the center position of the casing 1.

  A hollow injection pipe 4 is inserted into the sleeve pipe 3. The tip of the injection pipe 4 is provided with a pair of packers 4b, 4b that separate the space in the sleeve pipe 3 in the longitudinal direction, and between these packers 4b, 4b of the injection pipe 4, The ejection hole 4a is formed.

  Next, the construction procedure of the double pipe double packer method according to the present invention will be described in detail.

  First, the inner rod 2 with the excavation bit 2a at the tip is inserted into the casing 1 with the ring bit 1b at the tip, and the rear end of the inner rod 2 is connected to an advanced boring machine for geological exploration. Drill holes in natural ground G. Specifically, a striking force and a rotational force are given to the rear end of the inner rod 2 from an advanced boring machine for geological exploration, and a striking force and a rotational force are provided through the excavation bit 2a at the tip of the inner rod 2 and the excavation bit 2a. Is excavated in the natural ground G. In addition, the advanced boring machine for geological exploration uses what is always prepared in the tunnel excavation site of TBM method.

  After a predetermined length is drilled in the natural ground G with the casing 1 and the inner rod 2, the inner rod 2 (see FIG. 2) is pulled out to leave only the casing 1 in the natural ground G as shown in FIG. To do.

Next, as shown in FIG. 3B, the sleeve pipe 3 is inserted into the casing 1. At this time, since a plurality of wing members 3 c (see FIG. 1) are provided at the tip of the sleeve pipe 3, the sleeve pipe 3 is inserted while maintaining the center position of the casing 1. Thereafter, as shown in FIG. 3 (c), the seal material 6 is filled in the gap between the inner surface of the casing 1 and the outer surface of the sleeve pipe 3.
The sealing material 6 may be filled before the sleeve pipe 3 is inserted into the casing 1.

  Next, as shown in FIG. 3D, the injection pipe 4 is inserted into the sleeve pipe 3 so that the discharge hole 3a on the rearmost end side of the sleeve pipe 3 is positioned between the pair of packers 4b and 4b. The injection material 5 is press-fitted from the rear end of the injection pipe 4.

  The injection material 5 press-fitted from the rear end of the injection pipe 4 passes through the injection pipe 4 and through an ejection hole 4a (see FIG. 1) on the front end side, the outer surface of the injection pipe 4, the inner surface of the sleeve pipe 3, and a pair. The space formed by the packers 4b and 4b is filled. Thereafter, the injection material 5 expands the discharge hole 3a of the sleeve pipe 3 and jets it out of the sleeve pipe 3, and passes through the sealing material 6 filled in the gap between the outer surface of the sleeve pipe 3 and the inner surface of the casing 1. Flowing. And it is inject | poured into the natural ground G through the injection hole 1a of the casing 1 adjacent to the discharge hole 3a of the rearmost end side of the sleeve pipe 3, and the natural ground G is reinforced.

  When an appropriate amount of the injection material 5 is injected into the natural ground G around the casing 1, the injection of the injection material 5 is stopped, and the injection pipe 4 is moved by a predetermined distance in the distal direction, and the second from the rear end side of the sleeve pipe 3. The injection hole 5a is positioned between the pair of packers 4b and 4b, and the injection material 5 is injected again.

  Thereafter, the injection of the injection material 5 and the movement of the injection pipe 4 in the tip direction are repeated, and the natural ground G around the casing 1 is reinforced in order from the rear end side of the casing 1.

  Before injecting the injection material 5 into the natural ground G, the sealing material 6 may be cracked by supplying pressure water from the rear end of the injection pipe 4 in the same manner as the injection material 5.

  When the operation of injecting the injection material 5 into the natural ground G is finished, the injection pipe 4 is pulled out, and the casing 1 and the sleeve pipe 3 are left in the natural ground G as they are.

  According to the above embodiment, when the inner rod 2 is connected to the advanced boring machine for geological exploration to give a striking force and a rotational force, the striking force and the rotational force are excavated attached to the tip of the inner rod 2. It is transmitted to the ring bit 1b attached to the casing 1 via the bit 2a. Therefore, using the advanced boring machine for geological exploration, the natural ground G can be surely drilled by the casing 1 and the inner rod 2 inserted into the casing 1. After excavation, the inner rod 2 is pulled out, the sleeve pipe 3 is inserted into the casing 1, the seal material 6 is filled in the gap between the casing 1 and the sleeve pipe 3, and the injection pipe 4 is inserted into the sleeve pipe 3. The injection material 5 is press-fitted from the rear end of the injection pipe 4. Thereby, the injection material 5 is filled in the space formed by the inside of the sleeve pipe 3 and the pair of packers 4b and 4b through the ejection holes 4a of the injection pipe 4. Thereafter, the injection material 5 flows through the sealing material 4 filled in the gap between the casing 1 and the sleeve pipe 3 via the discharge hole 3 a of the sleeve pipe 3, and passes through the injection hole 1 a of the casing 1. The natural ground G is reinforced by being injected into G. Therefore, since the work of pulling out the casing 1 can be omitted, the double-pipe double-packer construction method can be performed by an advanced boring machine for geological exploration even on the site where there is no double-pipe excavator. It is not necessary to prepare and transport the machine, and the construction period can be prevented from being delayed. Moreover, since the casing 1 remains in the natural ground G even after the injection material 5 is injected into the natural ground G, the casing 1 can suppress deformation of the natural ground G.

  In the above embodiment, excavation is performed with an advanced boring machine for geological exploration, but it may be performed with a drill jumbo that is always provided at the site of NATM. In this case, in addition to the effects obtained in the above embodiment, the drill jumbo includes a plurality of drifters, so that a plurality of holes can be drilled simultaneously.

In the double pipe double packer construction method according to the present invention, it is a sectional view when an injection material is injected into a natural ground. It is sectional drawing when making a hole with a casing and an inner rod. It is a figure which shows the construction procedure in the double pipe double packer construction method which concerns on this invention, (a) is sectional drawing when an inner rod is pulled out after excavating with a casing and an inner rod, (b) is a sleeve pipe in a casing. (C) is a cross-sectional view when the gap between the casing and the sleeve pipe is filled with a sealing material, and (d) is a case where the injection material is injected by inserting the injection pipe into the sleeve pipe. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Casing 1a Injection hole 1b Ring bit 2 Inner rod 2a Drilling bit 3 Sleeve pipe 3a Discharge hole 3b Sleeve 4 Injection pipe 4a Ejection hole 4b Packer 5 Injection material 6 Sealing material

Claims (3)

A drilling bit for transmitting the striking force and rotational force received from a single-pipe excavator capable of single-pipe excavation to the ring bit was installed in a casing provided with a plurality of injection holes in the peripheral wall and attached to the tip of the ring bit. Insert the inner rod,
After drilling a natural ground by the inner rod connected to the single pipe excavator and the casing, after pulling the inner rod and excavation bit from the casing,
A pipe having a discharge hole is inserted into the casing, and a plurality of wing members are provided at the tip of the pipe so as to open radially outward and contact the inner wall of the casing. And further, a seal material is filled in the gap between the casing and the pipe,
Inserting an injection pipe comprising a pair of packers separating the space in the pipe into the pipe and an ejection hole provided between the packers,
In a state where the casing is installed in a natural ground, an injection material is supplied from the rear end of the injection pipe, and the injection material is injected from the injection hole into the natural ground via the ejection hole and the discharge hole,
After the injection pipe is pulled out, the casing and the sleeve pipe are left in the ground.   The double pipe double packer construction method according to claim 1, wherein the single pipe excavator is an advanced boring machine for geological exploration.   The double pipe double packer method according to claim 1, wherein the single pipe excavator is a drill jumbo.

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