JP4913494B2 - Ground improvement device. - Google Patents

Description

  The present invention relates to an apparatus for improving a ground by excavating the ground in a straight line and a curved line by using so-called free boring and injecting a hardener at a high pressure.

So-called boring means that the position information in the ground is acquired from the position information transmitter built in the transmission rod, and the ground is excavated in a straight line and a curved shape to form a long hole. The grout material is then injected.

A technique as described in Patent Document 1 is known as an example of the above-described free boring.
This is a device in which a position information transmitter is installed inside the front end rod that performs free boring, and a wire to which the position information transmitter and the front end rod are attached can be collected on the ground. A chemical solution injection tube is inserted into the long cavity after collection with the front end rod to inject the chemical solution into the ground.
JP-A-2005-155209.

In contrast to the existing apparatus as described above, the present invention provides a transmission rod in which cylindrical rods are connected along the longitudinal direction, a cylindrical front end rod attached to the front end of the transmission rod, and an interior of the front end rod. and slidably accommodating the excavation head and the position information transmitter, after collecting the position information transmitter and tunneling head, more configuration and high pressure jet pipe for insertion into the cavity of the collection trace, the high pressure jet pipe The front end is closed, and an injection hole is opened in a part of the front side surface. The injection hole is exposed in the ground in front of the outer cylinder , and the curing agent is injected from the injection hole into the ground at high pressure. This is a ground improvement device.

Since the present invention is as described above, the following effects can be expected.
<1> The ground can be improved with a simple device.
<2> In particular, the improvement can be performed on the ground below the existing structure or the like that cannot be handled by linear boring.
<3> Even if it is not the lower part of the existing structure, it is possible to improve sandy ground that is liable to be liquefied by an earthquake or soft ground that is liable to cause land subsidence due to a drop in groundwater level.

    Examples of the ground improvement device of the present invention will be described below.

<1> Precondition.
The ground improvement device of the present invention utilizes a so-called “universal boring device”.
The universal boring will be described in detail with reference to FIG. 2. A transmission rod 2 in which single pipes are connected along the longitudinal direction, a cylindrical front end rod 1 attached to the distal end of the transmission rod 2, and the front end rod 1 The digging head 12 and the position information transmitter 13 are slidably housed inside.
At that time, the front end surface of the front end rod 1 is not a plane perpendicular to the propulsion direction but forms a constant inclined surface, and the transmission rod 2 can rotate the front end rod 1; It is a feature that propulsive force can be given to the excavation head 12 by the pressure fluid passing through the transmission rod 2.
When straight excavation is performed, a propulsive force is applied to the front end rod 1 while the transmission rod 2 is rotated by the ground boring machine 5.
Since this rotational force is transmitted to the front end rod 1 and rotates, even if the tip is inclined, it can be moved straight without changing to one side by changing the position one after another.
On the other hand, when excavating in a curved shape, the rotation of the transmission rod 2 and the front end rod 1 is stopped at a set angle, and only propulsive force is applied.
Then, the pressure receiving inclined surface 12c at the front end of the front end rod 1 is guided to slide in the direction of the inclined surface by the earth pressure from the natural ground, and the curved excavation is gradually performed.
Which position in the ground is used for the straight excavation and from which position the curved excavation is performed is determined by receiving a signal from the position information transmitter 13 stored in the front end rod 1 on the ground.
Hereinafter, each device will be specifically described.

<2> Front end rod. (Figures 1 and 2)
The front end rod 1 is constituted by an outer cylinder 11 attached to the distal end of a transmission rod 2 in which single pipes are connected along the longitudinal direction, an excavation head 12 housed in the outer cylinder 11, and the like.
The inner diameter of the outer cylinder 11 of the front end rod 1 is the same as the inner diameter of the transmission rod 2, and the inside of the mounting type injection head 3 and the penetration type head 4 which will be described later can pass through the inside.
In the present specification, the front end and the front mean the direction in which the device advances during excavation.

<3> Outer cylinder. (Figures 1 and 2)
The outer cylinder 11 constituting the front end rod 1 is a cylindrical body, but the end face located forward when excavating, that is, the front end is not a plane orthogonal to the central axis of the cylinder but intersects at an angle other than 90 degrees, It is formed like a tip.
Although most of the inner surface is cylindrical, a step projecting inward is formed as an engaging step 11a on a part of the front end side.
A rotational force can be applied to the outer cylinder 11 from the ground via the rear transmission rod 2.
Furthermore, a protrusion parallel to the axial direction of the outer cylinder 1 is projected on the inner surface of the outer cylinder 11 as a key 11b.

<4> Excavation head 12. (Figures 1 and 2)
The member housed inside the outer cylinder 11 is constituted by the excavation head 12 and the position information transmitter 13.
The position information transmitter 13 is a device in which a transmitter and a battery for detecting and transmitting position information are incorporated in a cylindrical case.
The digging head 12 is a cylindrical body whose outer diameter is substantially equal to the inner diameter of the outer cylinder 11.
The front end of the digging head 12 is not a plane orthogonal to the central axis of the cylinder, but intersects at an angle other than 90 degrees, which is the same as that of the outer cylinder 11, and is processed like a bamboo tip like the front end of the outer cylinder 11. A pressure receiving inclined surface 12c is formed.
Further, a notch 12 b is formed in a part of the front end of the digging head 12, and this notch 12 b is engaged with a stepped portion 11 a protruding into the outer cylinder 11, so that the digging head 12 extends from the front end of the outer cylinder 11. Preventing forward exposure.
A position information transmitter 13 is attached to the rear of the excavation head 12 via a front rubber ring 14, and a pressure receiving disk 16 is attached to the rear of the position information transmitter 13 via a rear rubber ring 15.
The front rubber ring 14 and the rear rubber ring 15 have a disk shape that is short in the axial direction and has an outer diameter that allows loose elastic contact with the inner surface of the outer cylinder 11.
For this reason, while sealing performance with respect to a drilling fluid is ensured between the inner surfaces of the outer cylinder 11, since each rubber ring is a short disk shape, when collect | recovering the positional information transmitter 13, when the position information transmitter 13 is collect | recovered, the transmission rod 2 Even if there is a curve with a small radius, the rubber rings 14 and 15 can be easily passed by elastic deformation.
A key groove 12d is formed in a part of the digging head 12, and the key groove 12d engages with the key 11b on the inner surface of the outer cylinder 1 so that the rotation of the outer cylinder 11 can be transmitted to the digging head 12. Configure.

<5> Fluid passage.
The outer diameters of the rubber rings 14 and 15 and the outer diameter of the pressure receiving disk 16 are configured to be substantially equal to the inner diameter of the outer cylinder 11.
In each rubber ring 14, 15 and the pressure receiving disk 16, a flow path 17 that penetrates from the end face to the end face is formed.
The outer diameter of the position information transmitter 13 is configured to be sufficiently smaller than the inner diameter of the outer cylinder 11, and the space between the outer surface of the position information transmitter 13 and the inner surface of the outer cylinder 11 is used as a fluid passage.
The flow path 17 is also passed through the inside of the excavation head 12, and the front end thereof opens to the pressure receiving inclined surface 12c as the discharge port 12a.

<6> Injection head.
After the excavation head 12 and the like are pulled out from the inside of the outer cylinder 11, a long cavity is formed in the ground including the transmission rod 2.
A high-pressure injection head can be installed in the ground by using the cavity after drawing, but in the present invention, two types of injection heads, that is, the mounting type injection head 3 and the penetration type head 4 can be used. .

<7> Wearable injection head. (Figure 3)
One of the injection heads is a wearable injection head 3 shown in FIG.
The mounting type is because it is an injection head of a type that is inserted into the outer cylinder 11 and mounted as it is without penetrating the hollow outer cylinder 11 after the excavation head 12 and the like are pulled out.
Since the forward movement is restrained by being attached to the outer cylinder 11, when the outer cylinder 11 is retracted to the ground side, it is retracted integrally.
This mounting type injection head 3 is a nozzle body made of a tubular body having a through hole 31 for injecting a hardener and an open rear end.
The mounting type injection head 3 can be used as a simple tube or a tube in which a plurality of tubes are stacked like a double tube.
Therefore, in the case of a double pipe, the injection hole 31 is opened in two places, and in the case of a triple pipe, it is opened in three places.
The wearable injection head 3 is composed of a large diameter portion 32 and a small diameter portion 33.
The outer diameter of the large diameter portion 32 is formed to be substantially equal to the inner diameter of the outer cylinder 11, and the outer diameter of the small diameter portion 33 or smaller than that.
As a result, the step formed at the boundary between the large diameter portion 32 and the small diameter portion 33 is used as the stopper 34.
When the stopper 34 comes into contact with the step portion 11a inside the outer cylinder 11 of the front end rod 1, the wearable injection head 3 cannot be further advanced.
The position of the injection hole 31 of the mounting type injection head 3 is such that, when the mounting type injection head 3 is in contact with the step portion 11a of the outer cylinder 11 and the forward movement is prevented, the injection hole is forward of the front end of the outer cylinder 11, That is, it is set to a position exposed in the ground.
The stopper 34 is not limited to a configuration using a step, and can be adopted as long as the mounting type injection head 3 cannot penetrate the inside of the front end rod 1.
A wire 35 is attached to the rear end of the wearable injection head 3 so that the wearable injection head 3 after use can be recovered to the ground.
Further, a key groove is engraved in a part of the mounting type injection head 3 and can be fitted to a key 11b formed on the inner surface of the outer cylinder 11 to give the rotation of the outer cylinder 11 to the mounting type injection head 3. Configure to be.

<8> A penetration type head. (Fig. 6)
Another one of the injection heads is a penetrating head 4.
The penetrating type is not mounted on the outer cylinder 11 but is configured to penetrate the outer cylinder 11.
Therefore, when the outer cylinder 11 is retracted toward the ground, the outer cylinder 11 does not retract together with the outer cylinder 11 and penetrates the outer cylinder 11 and remains in the ground.
This penetrating head 4 is also a tubular body with the front end closed and the rear end opened, and can be used as a simple tubular body or a tubular body in which a plurality of tubes are stacked like a double tube.
An injection hole 41 is opened in a part of the front side surface of the penetrating head 4 so that high-pressure liquid supplied from the ground can be discharged to the outside.
Therefore, the injection hole 41 is opened in two places in the case of a double pipe and in three places in the case of a triple pipe.
The penetrating head 4 is formed so that its outer diameter is sufficiently smaller than the inner diameter of the outer cylinder 11 so as to penetrate the outer cylinder 11.
A high-pressure hose 42 for supplying a high-pressure fluid is connected to the rear of the penetrating head 4.

<9> Digging of the front end rod 1.
Next, the construction method will be described.
Using the boring machine 5 installed on the ground, along the guide tube 51, the front end rod 1 and the transmission rod 2 connected to the front end rod are inserted into the ground.
The front end rod 1 is configured by inserting an excavation head 12 and a position information transmitter 13 into an outer cylinder 11.
The transmission rod 2 is configured by connecting cylindrical single tube rods along the longitudinal direction.
By applying a rotational force to the rear end of the transmission rod 2 by the ground boring machine 5, the front end rod 1 at the tip can be rotated.
When a high pressure fluid is supplied to the inside of the transmission rod 2, the pressure receiving disk 16 is pressurized from behind, and a propulsive force is given to the excavation head 12.
The pressure-receiving inclined surface 12c located at the tip of the outer cylinder 11 is subjected to earth pressure.
Accordingly, if the forward force received by the pressure receiving disk 16 is set to be larger than the resistance received by the pressure receiving inclined surface 12c, it is possible to move forward in the ground together with the rotational force and the injection of the high-pressure fluid from the discharge port.
As described above, the pressure receiving inclined surface 12c of the excavation head 12 is used to cause the vehicle to go straight or pass through a curve based on a signal from the position information transmitter 13.
At that time, the high-pressure fluid supplied through the inside of the transmission rod 2 is jetted from the discharge port 12a at the tip of the excavation head 12 to cut and agitate the ground to facilitate advancement.
Thus, the excavation is continued and the front end rod 1 reaches the target position for ground improvement.
When it reaches, the supply of the high-pressure fluid is stopped, the wire 18 is wound up from the ground, the position information transmitter 13 in the outer cylinder 11 and the excavation head 12 are collected on the ground, and the outer cylinder 11 and the transmission rod 2 are brought into the ground. Leave it.

<10> Insertion and injection of the mounting type injection head 3.
Even if the excavation head 12 is pulled up and recovered from the outer cylinder 11 of the front end rod 1, both the outer cylinder 11 and the transmission rod 2 remain in the ground, and are located in the ground as continuous cavities.
The high pressure injection cylinder is inserted using the cavity after the pulling.
The case where the wearable injection head 3 is inserted into a cavity as one of the high pressure injection cylinders will be described.
When the wearable injection head 3 is inserted into the cavity in the transmission rod 2 and pressurized fluid is supplied from the ground, the pressure receiving surface 36 at the rear end of the wearable injection head 3 receives the pressure of the fluid and passes through the transmission rod 2. It moves forward and eventually arrives in the outer cylinder 11 of the front end rod 1 and is inserted into the outer cylinder 11 with the outer periphery closely attached. (Fig. 4)
When the mounting type injection head 3 reaches the outer cylinder 11, when the outer cylinder 11 is pulled back, the engagement step 11 a of the outer cylinder 11 is engaged with the stopper of the mounting type injection head 3. (Fig. 5)
As described above, the injection hole 31 is formed so as to be exposed to the front of the outer cylinder 11 in a state where the mounting type injection head 3 and the outer cylinder 11 are engaged.
In this state, if a solution such as a curing agent is supplied to the wearable injection head 3 through the transmission rod 2 at a high pressure, it can be injected into the ground from the injection hole 31 at the tip, and the periphery where the outer cylinder 11 is left. The ground can be improved to a cylindrical shape.
When the injection at one place is completed, the front end rod 1 is moved backward via the transmission rod 2.
Then, the wearable injection head 3 is also retracted by the retraction of the front end rod 1, and reaches the next improved position.
Therefore, a curing agent or the like is sprayed in the same manner.

<11> Insertion and ejection of the penetrating head 4.
Next, the case where the penetration type head 4 is inserted into the cavity as one of the high pressure injection cylinders will be described.
The penetrating head 4 is inserted into the cavity in the transmission rod 2, a high-pressure hose 42 is attached to the rear, and pressurized fluid is supplied into the hose 42 from the ground.
Then, the penetrating head 4 and the hose 42 are moved forward in the transmission rod 2 under the pressure of the fluid, and eventually arrive in the outer cylinder 11 of the front end rod 1.
And it inserts in the outer cylinder 11 in the state which left the margin on the outer periphery. (Fig. 7)
When the penetrating head 4 reaches the inside of the outer cylinder 11, the outer cylinder 11 is pulled back via the transmission rod 2. (Fig. 8)
Then, since the outer cylinder 11 and the penetrating head 4 are not engaged, only the outer cylinder 11 moves backward together with the transmission rod 2 toward the ground, and the penetrating head 4 remains in the ground. (Fig. 9)
In this state, a hardening agent can be supplied from the high-pressure hose 42 to the penetrating head 4 and injected into the ground through the injection hole 41 to improve the surrounding ground.
When the injection at one place is completed, the penetrating head 4 is retracted through the high-pressure hose 42 and the curing agent or the like is similarly injected at the next improvement position.
Thus, the ground at the required position can be improved.

The exploded explanatory view of one embodiment of the front end rod of the present invention. Explanatory drawing of the construction state of free boring and sectional drawing of a front end rod. Explanatory drawing of a mounting | wearing type injection head. Explanatory drawing of the state which inserted the mounting | wearing type injection head into the outer cylinder. Explanatory drawing of the state which the mounting | wearing type injection | pouring head exposes from the front end of an outer cylinder, and has injected the hardening | curing agent. Explanatory drawing of a penetration type head. Explanatory drawing of the state which the penetration type head inserted in the outer cylinder. Explanatory drawing of the state which the penetration type head is exposed from the front end of an outer cylinder, and is injecting the hardening | curing agent. Explanatory drawing of the state which only the penetration type head remains in the ground and injects the hardening | curing agent in the ground.

Explanation of symbols

1: front end rod 11: outer cylinder 12: excavation head 13: position information transmitter 16: pressure receiving disk 2: transmission rod 3: mounting type injection head 4: penetrating type head

Claims (3)

A transmission rod that connects cylindrical rods along the longitudinal direction;
A cylindrical front end rod attached to the tip of the transmission rod;
An excavation head and a position information transmitter slidably housed inside the front end rod,
After collecting the excavation head and the position information transmitter, it consists of a high-pressure injection cylinder to be inserted into the cavity of the collection trace,
The front end of the high-pressure injection cylinder is closed, and an injection hole is opened in a part of the front side surface. The injection hole is exposed to the ground in front of the outer cylinder, and the high pressure from the injection hole to the ground is high. A ground improvement device characterized by spraying a curing agent. High pressure injection cylinder
It is a nozzle body formed with a stopper part that cannot penetrate the inside of the front end rod left in the ground,
The ground improvement device according to claim 1. High pressure injection cylinder
It has an outer diameter smaller than the inner diameter of the front end rod left in the ground,
It is a nozzle body that can penetrate the inside of the front end rod,
The ground improvement device according to claim 1.

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