JPH0786224B2 - Ground improvement agitator and ground improvement method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention uses a stirrer used in a ground improvement method for forming a solidified body in the ground by mixing excavated soil and a solidifying material, and the same. It relates to the ground improvement method.

[Problems to be Solved by Prior Art and Invention]

After excavating the ground to the target depth with the excavating rod, after the excavation is completed, the excavated soil and the solidified material injected into the soil from the tip of the excavated rod are agitated, and the two are mixed to solidify such as piles in the ground. Conventionally, the method of forming a unit is to rotate the rod forward during excavation to perform excavation with the excavation bit at the tip of the rod, and reversely rotate it during extraction so that the soil and the solidified material are mixed with the stirring blade that projects on the rod. Stirring and mixing are performed.However, in the method using the excavating rod in which the stirring blade is projected on this rod, the excavated soil is mixed with the solidifying material by the stirring blade after the completion of the ground excavation There is a high possibility that a relatively large amount of soil mass will be produced when the mass is adhered around the stirring blade as a mass for a certain length in the axial direction and is rotated together with it.

If the soil mass generated during this excavation is mixed with the solidifying material as it is during stirring, the mixed state of the earth and sand and the solidifying material remains incomplete, resulting in a non-homogeneous solidified body and reducing its compressive strength. Since there is a risk of lowering it, it is always a construction issue to prevent the generation of this clod.

To solve this problem, a blade that is freely rotatable and has a length longer than the drilling diameter is projected on the drill rod, and the blade does not rotate when the rod is rotated by inserting the tip into the soil. There has been proposed a device for preventing the situation where the oil adheres to the stirring blade and simultaneously rotates.

This device prevents the rotation of blades etc. by the resistance of the soil around the drilled hole and cuts the excavated soil to a certain size at the time of stirring with the blade and the stirring blade to prevent the generation of clods. On the other hand, the present invention intends to newly propose an apparatus and a construction method for further finely crushing excavated soil during stirring to obtain a good mixed state.

[Means for Solving the Problems]

In the present invention, a crushing frame composed of a crushing blade and a connecting material for connecting the crushing blade is attached to the upper and lower sides of the stirring blade of the drilling rod so as to be rotatable and vertically movable with respect to the drilling rod, and relative to the drilling rod during stirring. By finely crushing the excavated soil with the vertically moving pulverizing blade and stirring blade, the excavated soil is prevented from adhering to the stirring blade in a lump state and rotating together with the excavating rod. Get mixed state with.

The crushing frame is rotatable with respect to the digging rod and axially reciprocally movable, and crushing blades are vertically arranged in parallel and project from the outer periphery of the digging rod, and a connecting member for connecting the upper and lower crushing blades to each other. The stirring blades are provided on the drill rod at an intermediate position between the upper and lower grinding blades of the grinding frame.

During agitation, the grinding frame rotates behind the excavating rod due to the resistance and inertia of the excavated soil, and when the excavating rod is moved up and down to promote mixing, the grinding frame also has a resistance and inertia. Between the crushing blade and the stirring blade located in the middle of the crushing blade, the crushing blade moves up and down within a range, whereby crushing of earth and sand is performed between the crushing blade and the stirring blade above and below the crushing blade. When the drilling rod is raised or lowered, the distance between one of the grinding blades and the stirring blade of the grinding frame is widened at the same time as the distance between the one of the grinding blades and the stirring blade of the grinding frame is narrowed. Due to the relative rotation of the crushing frame and the stirring blade, the earth and sand can be finely crushed between the crushing blade and the stirring blade on the side where the interval is narrow.

In addition, the crushing frame is rotatable with respect to the digging rod and is connected to the digging rod around the digging rod so as to reciprocate in the axial direction. It is possible to relatively raise and lower the digging rod by rotating the crushing frame relatively, and it is not necessary to forcibly rotate or raise and lower the crushing frame, and the structure of the stirring device is simplified.

For construction, rotate the excavating rod, excavate the ground while cutting the excavated soil with the grinding frame and stirring blade, and after reaching the predetermined depth, rotate the excavating rod while discharging the solidified material from the tip of the excavating rod. Then, the excavated soil is further crushed by the crushing blades and the stirring blades above and below the crushing frame, and at the same time, the crushed soil and the solidifying material are stirred and mixed to form a solidified body. The solidified material is also discharged from the time of excavation by the excavation rod.

〔Example〕

 The present invention will be described below with reference to the drawings showing one embodiment.

First, the invention described in the first claim will be described.

As shown in FIGS. 1-I and 2, the stirring device A of the present invention is provided with a crushing frame 2 which is attached to an excavating rod 1 so as to be rotatable and vertically movable with respect to the excavating rod 1, and which is provided at an intermediate position between them. The agitating blade 3 is used to crush the excavated soil produced by the excavation of the excavating rod 1 into fine particles to increase the degree of mixing with the solidifying material. FIG. 1-II is a plan view of I, where the left side of the center line represents the bottom surface and the right side represents the plane.

The crushing frame 2 has crushing blades 2 which are vertically arranged in parallel with each other.
It consists of a and 2a and connecting materials 2b and 2b connecting them, and the crushing blade 2
The outer pipes 2c and 2c are slidably inserted into the outer periphery of the excavation rod 1 so as to project therefrom.

The distance between the two ends on the plane of the crushing frame 2 is about the same as the diameter of the drilled hole, and the outer pipe 2c of the crushing frame 2 is separated from the digging rod 1 so that the crushing frame 2 can be rotated relative to this and can move up and down. It is in a free state.

The stirring blade 3 is provided so as to be surrounded by the crushing frame 2 so as to project on the excavating rod 1 at an intermediate position between the upper and lower crushing blades 2a, 2a
Its length is shorter than that of the crushing blade 2a.

As shown in the figure, ribs 4 and 4 are provided above and below the stirring blade 3 sandwiched by the crushing frame 2 to lock the outer tubes 2c, 2c of the crushing frame 2 and limit the range of movement thereof. The crushing frame 2 is movable within the range between the rib 4 and the outer tube 2c.

After excavation of the ground, the excavation rod 1 rotates while moving up and down,
The excavated soil and the solidified material are agitated. At this time, the crushing frame 2 is stationary or rotates at a low speed due to the resistance of the excavated soil, that is, the ground or ground soil. Relative rotation with 3, that is, an angular velocity difference is generated, and soil is cut and crushed between them.

Further, as shown in FIG. 1-I, when the excavating rod 1 rises, the crushing frame 2 also descends relative to this due to resistance or the like, and conversely, when the excavating rod 1 descends, as shown in FIG. The distance between the upper crushing blade 2a and the stirring blade 3 and the distance between the lower crushing blade 2a and the stirring blade 3 are shortened, and at this time, the distance between the crushing blades is reduced while rotating relatively. Wings
The soil will be more finely crushed between the 2a and the stirring blade 3.

The crushing of the earth and sand by the crushing blades 2a and the stirring blades 3 can be expected between the stirring blades 3 located above the crushing frame 2 when the crushing frame 2 rises with respect to the digging rod 1. The stirring blade 3 has the effect of pushing down the rising earth and sand and repeatedly crushing the earth and sand.

The earth and sand are pulverized to some extent when the ground is excavated as described later.

Further, by connecting a reduction gear to the crushing frame 2, it is possible to forcibly rotate the crushing frame 2 in the reverse direction with respect to the excavating rod 1.

Next, the invention described in the second claim will be described.

The present invention is a method for forming a solidified body in the ground by crushing excavated soil by using the agitator A of the first aspect of the invention and agitating the solidified material with the crushed soil.

First, the drill bit 5 at the tip is drilled by the rotation of the drill rod 1. At this time, as shown in FIG. 2, the crushing frame 2 rises relatively to the excavating rod 1, and the excavating soil is made to some extent by the crushing frame 2 and the stirring blade 3 which rotate with a delay relative to the excavating rod 1. Cut to size.
It is effective to discharge the solidifying material to be described later from the start of the drilling, and the solidifying material may be injected continuously from the drilling to the stirring or intermittently.

When the excavating rod 1 rotates, the excavating soil that rises is held down by the inclined stirring blades 3, and cutting is performed between the excavating soil and the crushing blades 2a of the crushing frame 2.

After the drilling rod 1 reaches a predetermined depth, it is rotated while discharging a solidifying material which is a slurry such as soil cement, mortar, or cement milk from its tip,
Stir and mix excavated soil and solidified material. This is done while moving the excavating rod 1 up and down.

When the excavating rod 1 is raised, as described in the invention of the stirring device A, the crushing frame 2 descends relative to the digging rod 1 and simultaneously rotates with a delay, so that the crushing blade 2a and the stirring blade 3 on the upper side thereof are rotated. The earth and sand are cut and crushed between and. On the contrary, when the digging rod 1 descends, the crushing frame 2 rises, and cutting and crushing are performed between the crushing blade 2a and the stirring blade 3 on the lower side thereof.

Simultaneously with the pulverization of the earth and sand, the earth and sand and the solidifying material are stirred and mixed to form a solidified body.

As described above, when it is necessary to accelerate the solidification of the soil, it is effective to start the discharge, stirring, and mixing of the solidified material from the time of excavation of the excavation rod 1.

〔The invention's effect〕

The present invention is as described above, and performs cutting and crushing of excavated soil by relative rotation and vertical movement of a crushing frame and a stirring blade that are rotatably and reciprocally connected to an excavating rod. As the rod moves up and down while rotating, the earth and sand can be pulverized more finely on the side where the space between the pulverization blade and the stirring blade of the pulverization frame is narrower.Therefore, the pulverized earth and sand and the solidifying material should be mixed uniformly. It is possible to produce a good, high-quality solid body.

Also, since the crushing frame is rotatable with respect to the excavating rod and is connected to the excavating rod around the excavating rod so as to be reciprocally movable in the axial direction, it is automatically rotated relative to the stirring blade only by rotating the excavating rod. It is not necessary to forcibly rotate or raise or lower the crushing frame by only raising or lowering the excavating rod, and the structure of the stirring device is simplified.

[Brief description of drawings]

FIGS. 1-I and II are an elevation view and a plan view showing the state of the excavating rod ascending respectively, and FIG. 2 is an elevation view showing the state of the excavating rod descending. A ... Stirrer, 1 ... Drilling rod, 2 ... Grinding frame, 2a ... Grinding blade, 2b ... Connecting material, 2c ... Outer tube, 3 ...
Stirring blade, 4 ... Rib, 5 ... Drilling bit.

Claims (3)

[Claims] 1. A device for agitating and mixing excavated soil and solidified material after excavation of the ground by an excavation rod, a stirring vane projecting on the peripheral surface of the excavation rod, and a vertical direction above and below the stirring vane. It consists of a crushing frame that is attached to the drilling rod at a distance and that crushes the excavated soil.The crushing frame consists of crushing blades that are parallel to each other above and below the stirring blade, and a connecting material that connects the upper and lower crushing blades to each other. A ground improvement agitator which is connected to the excavating rod so as to be rotatable and axially reciprocable. 2. A ground excavating rod is attached to the ground improvement agitator according to claim 1, and the ground is advanced while cutting the excavated soil with the grinding blade and the stirring blade of the grinding frame to reach a predetermined depth. After arriving, the excavating rod is rotated while discharging the solidified material from the tip of the excavating rod, and the excavated soil is further crushed by the crushing blades and stirring blades above and below the crushing frame, and at the same time,
A ground improvement method that stirs and mixes this crushed soil and solidifying material to create a solidified body. 3. The ground improvement method according to claim 2, wherein the solidified material is discharged from the time of excavation of the ground.