JPH07331648A - All-casing ground improvement device - Google Patents

Abstract

PURPOSE:To enable the execution of works even when there is an obstruction in peripheral soil by interiorly finishing a pipe force-feeding a solidifying agent to a casing tube and forming an all-casing ground improvement device of an agitating blade, a blade and a cover body opening and closing the pipe between the pipe and the tube. CONSTITUTION:A casing tube 1 and blades 4 are rotated through a driving device. The ground is excavated and cut by bits 2 for cutting at the front end section of the tube 1 while soil obstructions, etc., on the inner circumference of the tube 1 are excavated through bits 5 for excavation mounted on the blades 4. A solidifying agent is ejected from the front end of a force-feed pipe 3 in an excavation process, and the ground is excavated while the solidifying agent is mixed into soil. The ground is agitated by fixed blades 6a and free moving blades 6b, thus constructing a part of an improved body. Subsequently, the operation is repeated, thus manufacturing a complete improved body. Accordingly, the improved body having a positive sectional area is prepared while the execution of works is enabled even when there is the obstruction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an all-casing ground improvement device for improving soft ground.

[0002]

2. Description of the Related Art Conventionally, various devices have been known as a ground improvement device for soft ground (ground improvement device). Among them, a device for solidifying (solidifying) the ground in a cylindrical shape is well known. There is. Explaining the outline, the excavating shaft provided with the excavating blade and / or the stirring blade is rotationally excavated by a predetermined excavating mechanism, and the solidifying agent such as cement milk is discharged from the passage provided in the excavating shaft at the time of excavating or extracting. However, the gist is to consolidate the ground in a cylindrical shape through forced stirring and mixing of the solidifying agent and the excavated soil (excavated soil).

[0003] And as technical literature similar to this,
The following inventions may be mentioned. (1) Japanese Patent Laid-Open No. 5-132
There is a mixing and stirring blade device of the ground improvement machine of No. 926. The gist of the present invention is to provide a large number of excavation blades and co-rotation prevention blades on the excavation shaft, and to prevent co-rotation of the excavation blades and the excavated soil and solidifying agent through the co-rotation prevention blades. The purpose is to efficiently stir and mix the so-called excavated soil and the solidifying agent. (2) There is a ground stirring and mixing treatment apparatus disclosed in JP-A-5-179638. The gist thereof is a configuration in which auxiliary blades are rotatably provided on the radial free end side of a large number of stirring blades provided on a drive shaft, and a force is applied to the auxiliary blades to rotate in a direction opposite to the rotation direction of the stirring blades. The same effect as the above (1) is achieved for the purpose of (3) Japanese Patent Laid-Open No. 5-202515
There is a ground improvement machine of No. The gist of the invention is that the screw blade pieces are intermittently provided on the excavation shaft, and several rotary cylinders having crushed pieces are provided between the screw blade pieces.
After excavating the excavated soil mixed with the solidifying agent with a screw wing forcibly and introducing it into the rotary cylinder, the crushed soil mixed with the solidifying agent is further kneaded and crushed by a large number of crushed pieces of the rotary cylindrical body. Then, the purpose is to achieve uniform stirring and mixing of the excavated soil and the solidifying agent.

[0004]

Each of the inventions described in detail above has a structure in which the main constituent is an excavation shaft and a stirring blade. Therefore, there is a problem that the resistance against lateral pressing (earth pressure load), which is a drawback of ground improvement, is extremely weak, and the boundary between excavated soil and unexcavated soil (soil) is not fixed. The improved body having a large cross-sectional area is not constructed (created), the strength of the outer peripheral surface of the improved body is insufficient, or the soil around the improved body (hereinafter, simply referred to as the surrounding soil) has an obstacle. In this case, there are problems such as difficulty in construction.

[0005]

In view of the above, the present invention provides
The following configurations are adopted for the purpose of constructing an improved body with a reliable cross-sectional area, eliminating the lack of strength of the outer peripheral surface of the improved body, and being able to work even if there are obstacles in the surrounding soil. .

That is, the all-casing ground improvement device of the present invention comprises a casing tube in which a suitable number of cutting bits are provided at the peripheral edge of the tip in the excavation direction (drilling direction), and mortar and cement milk contained in the casing tube. , A pressure-feeding pipe for pressure-feeding a solidifying agent such as a powdery and granular improving material, a stirring blade provided in several groups between the pressure-feeding pipe and the casing tube, and a large number of blades arranged between the pressure-feeding pipe and the casing tube. And several blades provided with the excavating bit, and a lid for opening and closing the opening of the pumping pipe.

[0007]

Next, the operation of the present invention will be described. The casing tube and the vanes are rotated via a drive device (not shown). By this rotation, soil and obstacles near the inner and outer peripheral surfaces of the casing tube are excavated and cut with a cutting bit, and soil and obstacles on the inner peripheral surface of the casing tube are attached to the vanes (and the peripheral surface of the pumping pipe). There is also a case where the provided auxiliary bit for excavation may be used.) Excavation is performed through the excavation bit provided in. Then, normally, each bit is sequentially excavated into the ground while rubbing the soil in the excavation hole.
In this excavation process, the tip of the pumping pipe (not limited).
More solidifying agents such as cement milk, mortar, and powdery improver are jetted (jetted, discharged) and mixed into the excavated soil, and are sequentially dug into the ground. The excavated soil mixed with this solidifying agent is further agitated and mixed by the fixed blade and the free rotating blade which are advanced with a delay, and has excellent strength.
In addition, a part of the improved body (ground improved body, ground improved pillar, ground improved pile, etc.) having a predetermined cross-sectional area is constructed reliably and smoothly. After that, the above-mentioned operations and procedures are repeated, and finally the completed improved body is constructed.

It is of course possible to mix the solidifying agent into the excavated soil through the pressure-feeding pipe when the casing tube reaches the predetermined position in the ground. In this case, as described above, each bit is used to dig into the soil while unraveling the soil in the excavation hole, and the excavated soil taken into the casing tube is further rubbed with fixed blades and free-rotating blades. It is understood that the situation is sufficiently possible for efficient kneading with the solidifying agent as described later.

When the casing tube reaches the predetermined ground by the above-mentioned work and procedure, while rotating the casing tube (the rotation may be in the direction opposite to that at the time of excavation), the tip of the pressure feed pipe. The solidifying agent is ejected from the soil and mixed in the excavated soil. The excavated soil in which the solidifying agent is mixed is agitated and mixed by the fixed blade and the free rotating blade to construct an improved body in which the solidifying agent is mixed in the entire excavation hole.

Further, through normal rotation (for example, clockwise) driving of the casing tube and reverse rotation (for example, counterclockwise) operation (including driving) of the freely rotating blade and / or the fixed blade, It is also possible to employ a construction method (construction method) for further excavation, stirring, mixing, or the like.

It should be noted that the timing, sequence, and procedure of the solidification agent, the operation, and the mixing of the solidification agent into the excavated soil and the excavated soil, which are described in detail above, are merely examples, and needless to say, are not limited to the explanations and the illustrated examples.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Reference numeral 1 denotes a casing tube, and a large number of cutting bits 2, ... (Hereinafter, simply referred to as 2. It is also possible to use an excavating bit.) Are provided on the tip circumferential edge portion 1a of the casing tube 1. Has been. The cutting edge angle 2a of the cutting bit 2 can be changed in the radial direction (inward and outward directions of the wall surface of the casing tube 1), and an example of intermittent construction as shown in the figure or random Although the example configured by the formula is adopted, the point is that the optimum cutting edge angle 2a is used for various underground situations. Furthermore, the bit shape,
Dimensions, materials, etc. are free.

A pressure-feeding pipe 3 for pressure-feeding the solidifying agent is vertically provided in the casing tube 1, and a hollow cylindrical tip between the pressure-feeding pipe 3 and the casing tube 1 and in the excavating direction A of the casing tube 1. Several vanes 4 are provided in the part 1b. Then, a large number of excavating bits 5, ...
.. (hereinafter, simply referred to as 5) is provided vertically.
A bit (not shown) for excavation or agitation may be provided in the peripheral portion 3a of the tip of the pressure-feeding pipe 3. Further, the vane plate 4 may be delivered by a configuration in which the vane plate 3 is provided in an inclined state from the pressure feeding pipe 3 toward the tip circular edge portion 1a of the casing tube 1 as shown in the figure, or the pressure feeding pipe 3 and the tip circular edge portion 1a.
Alternatively, there is a configuration in which the casing tube 1 is provided in a horizontal state in another portion, and in principle, it is free. Reference numeral 31 is a lid that opens and closes the front end opening 3b of the pressure feeding pipe 3.
B in the figure shows an example of the rotating direction of the casing tube 1.

The pressure feed pipe 3 and the casing tube 1
Along with the longitudinal direction L, a stirring blade 6 formed by a combination of fixed blades 6a or free rotating blades 6b (each individual combination is also possible) is provided at an appropriate interval. In this example, the fixed blades 6a are the pressure feed pipes 3 The free rotating blade 6b is rotatably provided on the pressure feeding pipe 3. In principle, the combination of the fixed blade 6a and the free rotating blade 6b, the combination order, the interval, the radix, the position in the radial direction to be provided, the same radix, etc. are free. Further, the fixed blade 6a and / or the free rotating blade 6b may be provided on the inner wall surface 1c of the casing tube 1. In addition, the fixed blade 6a may be fixed by passing it between the pressure feed pipe 3 and the casing tube 1. Further, an auxiliary stirring blade (not shown) may be provided at the tip portion of the stirring blade 6. In the configuration in which the pressure feed pipe 3 is rotatably provided with respect to the casing tube 1, the pressure feed pipe 3 is inserted into the sleeve 7 provided in the central portion of the blade 4. In addition, a projection blade (not shown) is individually provided on the inner wall surface 1c of the casing tube 1.
Can be provided.

[0015]

As described in detail above, the present invention has a structure in which a casing tube having a cutting bit and an excavating bit is internally provided with a pressure feeding pipe, and a stirring blade is provided between the casing tube and the pressure feeding pipe. Therefore, it has the following effects.

(1) An improved body having a reliable cross-sectional area can be constructed.

(2) An improvement in the strength of the outer peripheral surface of the constructed improved body can be expected.

(3) Construction is possible even if there are obstacles.

(4) The casing tube can absorb lateral pressure, which is a drawback of ground improvement.

(5) Efficient stirring and mixing can be achieved.

(6) It is also possible to improve the stirring effect by attaching protruding blades to the casing tube, rotating the pressure feeding pipe in the reverse direction, and rotating the casing tube in the forward direction.

[Brief description of drawings]

FIG. 1 is an overall sectional view.

FIG. 2 is an enlarged sectional view showing a relationship between a casing tube, a blade, a cutting bit, and the like.

FIG. 3 is a schematic diagram showing a situation at the time of starting the construction (creation) of the improved body.

FIG. 4 is a schematic diagram showing a situation during construction (creation) of an improved body.

FIG. 5 is a schematic diagram showing a situation at the end of construction (creation) of an improved body.

FIG. 6 is a cross-sectional view of a main part showing another example of the casing tube and the pressure feed pipe.

[Explanation of symbols]

 1 Casing Tube 1a Tip Circumferential Edge 1b Hollow Cylindrical Tip 1c Inner Wall 2 Cutting Bit 2a Blade Edge Angle 3 Pumping Pipe 3a Tip Peripheral 31 Cover 4 Blade 5 Excavation Bit 6 Stirring Blade 6a Fixed Blade 6b Free Rotating Blade 7 Sleeve A Direction of excavation B Rotation direction L Longitudinal direction

Claims (3)

[Claims] 1. A casing tube in which an appropriate number of cutting bits are provided on the circumferential edge of the tip in the direction of excavation, and a pressure feed for pressure-feeding a solidifying agent such as mortar, cement milk, and an improvement agent in the form of powder or granules contained in the casing tube. A pipe, a few stirring blades provided between the pressure-feeding pipe and the casing tube, and a number of blades provided with a large number of excavating bits that are placed between the pressure-feeding pipe and the casing tube, An all-casing ground improvement device comprising: a lid that opens and closes the opening of the pumping pipe. 2. The all-casing ground improvement apparatus according to claim 1, wherein the stirring blade of claim 1 is composed of a fixed blade and / or a free-rotating blade provided on the pressure feeding pipe. 3. The all-casing ground improvement device according to claim 1, wherein the plurality of blades according to claim 1 are provided on the casing tube and / or the pressure feed pipe in an inclined shape.