JP3177452B2 - Construction method of high pressure injection 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 high-pressure injection method particularly suitable for ground improvement.

2. Description of the Related Art One of the ground improvement methods is a high-pressure injection method. In this method, after drilling to the target depth with a boring machine, the improving material (grout) is injected at a high pressure from the lower end of the injection rod, and the ground is cut and at the same time, the soil particles and the improving material are mixed and stirred, or replaced. This is a construction method to form a columnar consolidated body by using. The method of forming the consolidated body can be roughly classified into (1) a high-pressure injection method (such as a CCP method) in which only the improving material is injected at high pressure, and (2) a high-pressure injection stirring in which the improving material is injected at high pressure with air. It is classified into two methods (JSG method, column jet method, etc.).

Conventionally, in this type of high-pressure injection method, when a hard ground such as a gravel layer intervenes in the target ground and drilling by the injection rod itself is difficult, a tip such as a ring bit or a metal crown is provided at the tip. The ground is drilled with a casing pipe provided with an opening bit, the casing pipe is installed in the ground, an injection rod is built in the casing pipe, and then the casing pipe is pulled up while the injection rod is left in the ground. (Pull out or pull up halfway).

[0003]

However, the above prior art has the following problems. When drilling with a casing pipe, a drill bit is clogged in the casing pipe during drilling because a tip bit such as a ring bit or metal crown is used, so-called core clogging often occurs. In order to remove the excavation degree, the casing pipe has to be lifted (withdrawn) once to the ground. Therefore, it takes a lot of labor to lift the casing pipe and remove the excavated soil, and it takes a long time to drill holes in the casing pipe, which increases the construction cost.

[0004] The present invention has been made in view of such problems, and an object thereof is to provide a construction method of a high-pressure injection method capable of shortening the construction period, reducing the construction cost, and reducing the construction labor. Is to do.

[0005]

The gist of the invention according to claim 1 is that, after drilling a hole to a target depth, an improved material is injected at a high pressure from an injection nozzle provided at a lower end of an injection rod to cut the ground. At the same time, mixing and stirring the soil particles and the improver,
Alternatively, a high-pressure injection method for forming a columnar consolidated body by replacement, comprising: (1) an axially connected casing pipe provided with an outer bit at a tip, and a tip in the casing pipe. A step of drilling the ground with the inner bit assembly inserted into the portion, the bite portion being provided at the rear end and the inner bit being non-detachably attached to the tip, and installing the casing pipe in the ground. (2) Inserting an inner bit lifting device having a bite portion at the front end capable of biting with the bite portion and having a rear end portion connected to a wire into the casing pipe; The bite portion is engaged with the bite portion of the existing inner bit assembly, and the inner bit is pulled together with the inner bit by pulling out the wire. A step withdraw the assembly,
(3) a step of embedding the injection rod in the casing pipe; (4) a step of pulling up the casing pipe with the injection rod remaining; and (5) an improvement from the injection nozzle while rotating the injection rod. and a step of injecting the timber to construct a consolidated body, said casing Pas
Around the top casing (12) located at the tip of Ip
The protrusion (12a) provided in a part of the direction opens and closes in the radial direction
Freely, the base of the inner bit assembly (20)
At the approximate center of the cylindrical inner tube (21)
Attached, located on the opposite side in the radial direction, the latch spring
The latch (2) urged radially outward by (28)
7) By pressing the side surface (27b), the inner bit
The rotation of the assembly (20) causes
Narbit is a construction method of a high pressure injection method characterized by drilling a ground . The gist of the invention according to claim 2 is that after drilling to the target depth, the improving material is injected at a high pressure from an injection nozzle provided at the lower end of the injection rod, and the ground is cut and simultaneously the soil particles and the improving material are mixed. A method of applying a high-pressure injection method for forming a columnar consolidated body by stirring or replacing, wherein (1) an outer bit is provided at a tip, and an axially connected casing pipe;
The casing pipe is ground by drilling the ground with an inner bit assembly inserted into the front end of the casing pipe and having an occlusal portion provided at the rear end and an inner bit irremovably attached to the front end. (2) inserting an inner bit lifting device having a bitable portion at the front end in which the biting portion can bite and a rear end portion connected to a wire into the casing pipe; (3) engaging the bite portion of the inner bit assembly at the end of the pipe with the bite portion and pulling up the wire to pull up the inner bit assembly together with the inner bit; and (3) attaching the injection rod to the casing. (4) pulling up the casing pipe with the injection rod remaining. Comprising a step, and a step of Construction (5) the by injecting modifying material injection rod from the injection nozzle while rotating solidification body, ahead of the casing pipe
Part of the circumferential direction of the top casing (12) located at the end
The convex part (12a) provided in the opening and closing freely in the radial direction,
A cylinder forming a base of the inner bit assembly (20)
Attached to the approximate center of the inner tube (21)
Latch spring (28)
Side of the latch (27) urged radially outward by the
Pressing the surface (27b), said inner bit assembly
By rotating (20), the inner bit
G is in the construction method of high pressure injection method characterized by drilling the ground . Summary of the Invention of claim 3, wherein the tubular
The inner tube (21) forms a base,
On the proximal side of the tube (21), the occluded part (22) is provided.
Attached , the occlusal part (22) is a male on the proximal end side.
The part (22a) has a cross-shaped leg (22b) on the tip side.
And the legs (22b) are formed by spear pins (23).
The spear holder (24), which is a short tubular body.
Attached to the occlusal part (22) and the spear holder
-(24) closes the proximal end of the inner tube (21)
In the inner bit assembly (20) which is not closed
The method according to claim 1 or 3, wherein the hole is drilled while water is sprayed from the portion to the hole drilling surface .

The term "pulling up" in "(4) the step of pulling up the casing pipe while leaving the injection rod remaining" in the present invention means that the present invention is practiced in a case where the casing pipe is completely pulled out or a case where the casing pipe is pulled up halfway. The method includes a suitable step.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, a drilling device 1 used in the construction method of the high-pressure injection method according to the present embodiment will be described. As shown in FIG. 1, the drilling device 1 is for drilling a ground G in a vertical direction, and is roughly composed of a casing pipe 10 and an inner bit assembly 20 inserted therein and located on the distal end side. ing. In the present embodiment, the tip side refers to the side of the drilling direction (the direction indicated by the white arrow in FIGS. 1 and 2). In the figure, reference numeral 40 denotes an overshot, and reference numeral 50 denotes a wire. FIG. 1 is simplified for the sake of space.

As shown in FIG. 2, the casing pipe 10 has a plurality of rods 11 connected in the axial direction, and a top casing 1 connected to the rods 11 and located at the tip.
2 is roughly constituted.

The rod 11 is a cylindrical body having an external thread at the distal end and an internal thread at the proximal (ground) end.

The top casing 12 has an outer bit 13 screwed to the distal end and a female thread cut to the proximal end. The male screw of the rod 11 is screwed to this female screw, and the outer bit 13 is located on the distal end side. The inside diameter of the portion where the latch 27 comes into contact is larger than the inside diameter of the distal end of the rod 11, and a step 11a is formed. Further, as shown in FIGS. 2 and 3, a convex portion 12a is provided in a part of the circumferential direction so as to extend in the axial direction.

As shown in FIG. 2, the inner bit assembly 20 has a cylindrical inner tube 21 as a base. An inner bit 33 is screwed to the distal end side of the inner tube 21. A spear (occlusal portion) 22 is attached to the proximal end side of the inner tube 21.

As shown in FIGS. 2 and 4, the spear 22 has a male portion 22a (not shown in FIG. 4) on the base end side.
A cross-shaped leg 22b is formed on the distal end side. The leg 22b is attached to a spear holder 24 by a spear pin 23.

The spear holder 24 is a short tubular body. A flange 24a protruding radially inward is formed on the proximal end, and a male screw is cut on the distal end. The spear holder 24 is attached to the latch holder 25.

As shown in FIGS. 2 and 5, the latch holder 25 is a substantially cylindrical body having two latch holding pieces 25a at the distal end side, and is provided with a base of the inner tube 21 (not shown in FIG. 5). The end outer surface is slidably covered in the axial direction. The two latching pieces 25a have the same shape, are curved with the same curvature as the cylindrical portion, and are spaced at a predetermined interval in the circumferential direction. A rectangular latch hole 25b is opened at a substantially central portion in the longitudinal direction of each latch holding piece 25a. A bolt hole 25c is formed in the base. This bolt hole 25c
The latch holder 25 is attached to the inner tube 21 by a pair of stopper bolts 26 (not shown in FIG. 5) which are provided on the opposite side in the radial direction.

The latch 27 is attached to the inner tube 21 substantially at the center so as to be freely opened and closed in the radial direction. The two latches 27 are located on opposite sides in the radial direction as shown in FIG.
It is urged radially outward by a latch spring 28 (not shown in FIG. 3). Therefore, the latch holder 2
5 is attached to the inner tube 21,
The outer portion of the latch 27 in the radial direction is inserted into the latch hole 25b shown in FIGS.

At the proximal end of the inner tube 21,
As shown in FIG. 2, a spring push 32 is screwed. The spring push 32 is a short tubular body,
A flange 32a protruding radially outward is formed at the proximal end. The proximal end surface of the flange 32a is
The spear holder 24 is in contact with the front end surface. The flange 32a is pressed by a spring 31 interposed between the front end surface and the inner peripheral projection 25e of the latch holder 25. The spring 31 presses the spring push 32 toward the proximal end, and the latch holder 25 screwed to the spear holder 24 is in a state of being urged toward the distal end. In the figure, reference numerals 29 and 30 are O-rings.

Next, an overshot 40 (inner bit lifting device) for lifting the inner bit assembly 20 will be described. Overshot 40
Is connected to a wire 50 as shown in FIG. 6, and a spear latch 41 (occlusal portion) is provided at the tip.

The spear latch 41 has two latch pieces 42.
(The latch piece 42 indicated by a two-dot chain line on the right side of the paper is shown in an open state) is a washing scissors-like member rotatably connected by a spring pin 43 at a substantially central portion. The distal end side is formed in a shape that can bite the spear 22. The proximal end is urged by a latch spring 45 so that the distal end is closed. The spear latch 41 is connected to a latch out ring 46 by another spring pin 44. The latch out ring 46 is connected to a pipe 48 via a hanger shaft 47. A cap 49 is screwed on the proximal end of the pipe 48.

Next, the operation of the drilling apparatus 1 configured as described above will be described with reference to FIGS. 7 to 9 are partial sectional views. The latch 27 is depicted on its side.

During excavation, as shown in FIG. 7, the step 11a of the rod 11 presses the free end 27a of the latch 27 so that the rod 11 pushes the inner bit assembly 20. At the same time, the protruding portion 12a of the top casing 12 shown in FIG. 3 presses the side surface 27b of the latch 27 to rotate the inner bit assembly 20. By these operations, the inner bit 33 (FIGS. 7 to 9)
(Not shown) can drill the ground (the casing pipe 10 itself including the rod 11 is rotated and excavated by a boring machine installed on the ground surface). As a result, the ground can be drilled by the inner bit 33 together with the outer bit 13 (not shown in FIGS. 7 to 9). As the outer bit 13, an existing ring bit, metal crown, or the like can be used. As the inner bit 33, a bit having the same shape as an existing cross bit or button bit can be used.

The overshot 40 (not shown in FIGS. 7 to 9) connected to the wire 50 is lowered into the casing pipe 10, and the spear latch 41 urged radially inward is connected to the spear 22 shown in FIG. When it abuts, it opens along its shape and engages the spear 22 as shown in FIG.

When the wire 50 is wound up with the spear latch 41 engaged with the spear 22, the latch holder 2
5 slides to the proximal end side, and the inner end surface 25d also shown in FIG. When the wire 50 is further wound, as shown in FIG.
5d presses the latch 27 to close it. When the wire 50 is further wound up, the front end surface 25f shown in FIG. Further wire 50
, The inner bit assembly 20 can be pulled up.

Next, a construction method of the present high-pressure injection method using the drilling device 1 will be described with reference to FIGS.

First, as shown in FIG. 10, a ground G is drilled to a predetermined depth by a drilling device 1 so as to form a casing pipe 1.
0 is installed underground.

After the drilling is completed, the wire 50 is wound up and the inner assembly 20 is pulled up by the overshot 40 as shown in FIG.

Next, as shown in FIG. 12, an injection rod 60 for injecting the grout material is connected to the casing pipe 10.
Build in.

Next, as shown in FIG.
The casing pipe 10 is pulled up with 0 remaining.
At this time, the casing pipe 10 is generally completely pulled out to the ground. However, when the hole wall of the excavation hole is not stable, or when the excavated earth and sand during the construction of the improved body cannot be smoothly discharged to the ground, the casing pipe 10 is pulled up to a predetermined position without being completely pulled out. Sometimes it stops at a position. In the figure, reference numeral 61 denotes an injection nozzle 61 for injecting the grout material g.

Next, after the injection rod 60 is inserted into the ground in this manner, as shown in FIG. 14, the injection rod 60 is rotated and the distal end of the injection rod 60 is rotated in accordance with the existing high pressure injection method. Injection nozzle 61 provided
Then, the grout material g is injected into the ground G to form the consolidated body C.

After forming the consolidated body C to a predetermined depth, the injection rod 60 is pulled up to fill the hole.

Next, the effect of the construction method of the high-pressure injection method according to this embodiment will be described.

Since the inner bit 33 is provided at the tip of the casing pipe 10, casing drilling can be performed without causing clogging of the core of the casing pipe 10, and an operation of removing the clogged core by pulling up the casing pipe 10 can be performed. It becomes unnecessary. Also, the inner bit assembly 20 can be quickly pulled up simply by engaging the overshot 40 attached to the tip of the wire 50 with the inner bit assembly 20 and winding up the wire 50. Injection rod 60 in casing pipe 10
Can be built. As a result, the construction period can be shortened, and the construction cost can be reduced.

In actual drilling, it is preferable to drill while spraying water from the inside of the inner bit assembly 20 to the drilling surface. Such water discharge is possible because the spear 22 and the spear holder 24 do not block the base end side of the inner tube 21 as shown in FIGS.

Further, the rod 11, the top casing 1
2. The length, diameter and shape of the inner bit assembly 20 may be suitable for practicing the present invention unless otherwise specified.

In the above embodiment, the spear (occlusal portion) 22 is attached to the inner bit assembly 20.
Although the spear latch (occlusal portion) 41 is provided on the overshot 40, in the present invention, the occlusal portion may be provided on the inner bit assembly 20 and the occlusal portion may be provided on the overshot 40.

The occlusal portion and the occlusal portion are not limited to those in the above-described embodiment, and any structure may be used in the present invention as long as they can occupy each other.

In the present invention, the CCP method, J
A high-pressure injection method suitable for carrying out the present invention, such as the SG method and the column jet method, can be used. In the above figure, the same components are denoted by the same reference numerals.

[0037]

Since the present invention is configured as described above, the following effects can be obtained. (1) Since the inner bit 33 is provided in the casing pipe, casing drilling can be performed without causing clogging of the core in the casing pipe.

(2) By simply pulling out the wire, the inner bit attached to the tip of the casing pipe can be pulled up, and the injection rod can be built into the casing pipe immediately after drilling.

(3) At the time of drilling, since the inner bit is attached to the front end of the casing so as not to fall off, it can be rotated both forward and reverse, and drilling can be performed efficiently.

As described above, according to the present invention, the construction period can be shortened, the construction cost can be reduced, and the construction labor can be reduced.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of a drilling apparatus according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 3;

FIG. 3 is a sectional view taken along line BB of FIG. 2;

FIG. 4 is a sectional view taken along the line CC of FIG. 2;

FIG. 5 is a perspective view of a latch holder.

FIG. 6 is a side view of an overshot.

FIG. 7 is a view showing the operation of the drilling device.

FIG. 8 is a diagram showing the operation of the drilling device.

FIG. 9 is a diagram showing the operation of the drilling device.

FIG. 10 is a process diagram of a construction method of a high-pressure injection method according to the embodiment.

FIG. 11 is a process diagram of a construction method of a high-pressure injection method according to the embodiment.

FIG. 12 is a process diagram of a construction method of a high-pressure injection method according to the embodiment.

FIG. 13 is a process diagram of a construction method of a high-pressure injection method according to the embodiment.

FIG. 14 is a process diagram of a construction method of a high-pressure injection method according to the embodiment.

[Explanation of symbols]

 C Solid body g Grout material 1 Drilling device 10 Casing pipe 11 Rod 11a Stepped portion 12 Top casing 12a Convex portion 13 Outer bit 20 Inner bit assembly 21 Inner tube 22 Spear 22a Male portion 22b Leg 23 Spear pin 24 Spear holder 24a Flange Part 25 Latch holder 25a Latch sandwiching piece 25b Latch hole 25c Bolt hole 25d Inner end face 25e Inner peripheral convex part 25f End side end face 26 Stopper bolt 27 Latch 27a Free end 27b Side surface 27c Fixed end 28 Latch spring 29, 30 O-ring 31 Spring 32 Spring Push 32a Flange 33 Inner bit 34 Water supply channel 40 Overshot 41 Spear latch 42 Latch piece 43, 44 Spring pin 45 Latch spring 46 Latch out ring 47 Hanger shaft 48 Pipe 49 Cap 50 Wire 60 Injection rod 61 Injection nozzle

Claims (3)

(57) [Claims] After drilling a hole to a target depth, an improving material is injected at a high pressure from an injection nozzle provided at a lower end of an injection rod, and at the same time as the ground is cut, soil particles and the improving material are mixed and stirred, or A high-pressure injection construction method for forming a columnar solid body by replacement, comprising: (1) an axially connected casing pipe provided with an outer bit at a tip thereof, and a tip portion in the casing pipe. A step of mounting the casing pipe in the ground by drilling the ground with an inner bit assembly in which the bite to be engaged is provided at the rear end and the inner bit is non-detachably mounted at the front end, (2) having at its tip an occlusal portion capable of occlusal engagement with the occluded portion;
An inner bit lifting device having a rear end connected to a wire is inserted into the casing pipe, and the bite portion is engaged with the bite portion of the inner bit assembly at the tip of the casing pipe, and the wire is pulled out. (3) erecting the injection rod in the casing pipe, (4) elevating the casing pipe with the injection rod remaining, (5) forming a consolidated body by injecting an improving material from the injection nozzle while rotating the injection rod, wherein the top casing is located at a tip of the casing pipe.
(12a) provided on a part of the lug (12) in the circumferential direction
The inner bit assemble can be freely opened and closed in the radial direction.
Cylindrical inner tube (2)
1) is attached to the approximate center, located on the opposite side in the radial direction,
Biased radially outward by the latch spring (28)
Press the side surface (27b) of the latch (27)
For the operation of rotating the inner bit assembly (20)
Therefore, the inner bit drills the ground, and the high-pressure injection method is applied. 2. After drilling a hole to a target depth, an improving material is injected at a high pressure from an injection nozzle provided at a lower end of an injection rod, and at the same time as the ground is cut, the soil particles and the improving material are mixed and stirred, or A high-pressure injection construction method for forming a columnar solid body by replacement, comprising: (1) an axially connected casing pipe provided with an outer bit at a tip thereof, and a tip portion in the casing pipe. A step of installing the casing pipe in the ground by drilling the ground with an inner bit assembly in which the bite portion is provided at the rear end and the inner bit is non-detachably attached to the tip at the rear end, (2) The bite portion has a bite portion that can bite at the tip,
An inner bit lifting device having a rear end connected to a wire is inserted into the casing pipe, a bite portion of the inner bit assembly at a tip portion of the casing pipe is bited by the bite portion, and the wire is pulled out. (3) erecting the injection rod in the casing pipe, (4) elevating the casing pipe with the injection rod remaining, (5) forming a consolidated body by injecting an improving material from the injection nozzle while rotating the injection rod, wherein the top casing is located at a tip of the casing pipe.
(12a) provided on a part of the lug (12) in the circumferential direction
The inner bit assemble can be freely opened and closed in the radial direction.
Cylindrical inner tube (2)
1) is attached to the approximate center, located on the opposite side in the radial direction,
Biased radially outward by the latch spring (28)
Press the side surface (27b) of the latch (27)
For the operation of rotating the inner bit assembly (20)
Therefore, the inner bit drills the ground, and the high-pressure injection method is applied. 3. A base material comprising : a tubular inner tube (21);
And a proximal end of the inner tube (21)
The occlusal part (22) is attached, and the occlusal part (2 ) is attached.
2) is a male part (22a) at the base end and a cross at the tip end
A leg-shaped leg (22b) is formed, and the leg (22b) is
A spiaho which is a short tubular body is formed by a pier pin (23).
The occlusal part (22) is attached to the rudder (24).
And the spear holder (24) is an inner tube.
(21) The inner bit of which the base end side is not closed.
While spraying water from inside the assembly (20) to the drilled surface
The method according to claim 1, wherein the hole is drilled from the hole .