JPH0223640Y2 - - Google Patents

Description

[Detailed explanation of the invention] <<Industrial application>> This invention involves injecting a consolidating material while excavating the ground, and stirring and mixing this with the excavated soil to form column piles or connected columns in the ground. The present invention relates to a device for forming an underground continuous wall.

《Prior Art》 This type of conventional excavation agitation mixing device for forming columnar piles consists of a rotating vertical shaft that is inserted into the ground and driven to rotate, and an excavating bit attached to the lower end of this rotating vertical shaft. , a plate-shaped stirring blade installed in the horizontal direction (radial direction) around the lower part of the rotating vertical shaft, and a plate-shaped stirring blade installed near the bit, which discharges the consolidated material pressure-fed into the feeding path in the rotating vertical shaft. It is equipped with a nozzle section.
While excavating the ground with a bit, the consolidating material is discharged from the nozzle part, the rotating vertical shaft is driven to rotate, the consolidating material and the excavated earth and sand are stirred and mixed by the plate-shaped stirring blade, and the consolidating material is hardened. It formed a row of pillar piles.

<<Problems to be solved by the invention>> In conventional devices, the plate-shaped stirring blades are attached horizontally to the rotating shaft at an angle, so when the vertical shaft of rotation is rotated, the area around the stirring blades is The earth and sand only moves up and down, and even if the compacting material is discharged, the mixing effect with the excavated earth and sand is insufficient, and uniform mixing is difficult. Further, stirring and mixing by the plate-shaped stirring blades is only possible in a very localized area, and it is difficult to uniformly mix the compacting material and the excavated soil over a wide area. It was difficult to make the strength of the column piles formed as a result uniform in the depth direction. Here, for example, the height direction of the rotating vertical shaft (the depth direction of the ground) can be covered to some extent by attaching a plurality of plate-shaped stirring blades to the rotating vertical shaft. However, it is very difficult to expand the stirring and mixing area laterally. Although it is possible to expand the stirring area laterally by increasing the length of the plate-shaped stirring blades, this requires a very large driving force and is not practical.

This idea was devised in view of the conventional problems mentioned above, and its purpose is to be able to thoroughly mix excavated soil and consolidation material over a wide range of depth and lateral directions in a short time. With this, an object of the present invention is to provide an excavating, stirring, and mixing device for forming column piles that can form column piles that are homogeneous in the depth direction when the consolidation material hardens to form column piles.

《Means for solving the problem》 Therefore, in this invention, a plurality of rotating vertical shafts supported in parallel at predetermined intervals and rotationally driven;
An excavation bit attached to the lower end of each rotating vertical shaft, an arc-shaped stirring blade attached vertically around the lower part of each rotating vertical shaft, and an upper and lower position of the arc-shaped stirring blade on each rotating vertical axis. plate-shaped stirring blades installed in the horizontal direction at respective positions, and nozzles provided near the arc-shaped stirring blades on each vertical axis of rotation to discharge the consolidated material pressure-fed into the feeding path on each vertical axis of rotation. The arc-shaped stirring blades and the plate-shaped stirring blades of each vertical axis of rotation are configured to rotate without interfering with each other, and the rotation trajectories of each blade are partially overlapped with each other in a plane. It was configured as follows.

<<Operation>> The above-mentioned arc-shaped rotor causes the excavated soil to flow laterally, and expands the stirring range laterally. In addition, the vertical flow caused by the plate-shaped stirring blades and the lateral flow caused by the arc-shaped stirring blades are combined, increasing the stirring and mixing effect. Furthermore, multiple vertical rotating shafts are arranged in parallel, and the agitation areas of each axle partially overlap, so excavated soil and compacted material can be agitated and mixed over a very wide area in one operation. It can be performed.

<<Embodiment>> FIG. 1 shows an outline of a working state using an apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 10 indicates a truck that travels on a caterpillar, 12 a support device attached to the truck 10, and 14 an excavating, stirring and mixing device for forming columnar piles according to the present invention, which is supported by the support device 12. This excavation forming device 1
4 is shown in detail in FIGS. 2 and 3.

The excavation agitation mixing device 14 has three rotating vertical shafts 16,
16, 16. Each rotating vertical shaft 16 is supported in parallel by a bearing holder 18 at a predetermined interval,
It is rotatable. A drive mechanism 20 is provided at the upper end of the vertical rotating shaft 16, and each vertical rotating shaft 16 is driven to rotate at a constant speed and with a constant phase difference.

At the lower end of each rotating vertical shaft 16 is a drilling bit 22.
The ground is excavated using this bit 22, and the rotary vertical shaft 16 is inserted to a predetermined depth. The lower end of the central rotating vertical shaft 16 is located above the left and right sides, so that the three bits 22 can rotate without interfering with each other. Third
Figure D shows the excavation cross-section with three bits 22. As shown in the figure, the circular excavation areas by each bit partially overlap each other, and the ground is excavated in a horizontally long cross-sectional area as a whole.

Around the lower part of each rotating vertical shaft 16 are arc-shaped stirring blades 2.
4 and plate-shaped stirring blades 26 are attached. The arc-shaped stirring blades 24 are formed by bending a metal strip into a semicircular shape, and both ends thereof are fixed to the circumferential surface of the vertical rotating shaft 16 in the vertical direction. Two arcuate stirring blades 24 form a set, and the arcuate stirring blades 24, 24 are arranged at the same height position so that the two semicircles combine to form a substantially circular shape.
They are installed at 180° intervals.

The plate-shaped stirring blades 26 are formed by twisting a metal plate into a propeller shape, and are attached to positions above and below the arc-shaped stirring blades 24 so as to protrude laterally. The plate-shaped stirring blades 26 are also a set of two, and protrude on both sides at the same height position of the rotating vertical shaft 16 at an interval of 180°.

As also shown in FIG. 3C, the central vertical axis of rotation 16
The mounting phase of the arcuate stirring blades 24 differs by 90 degrees between the left and right rotational vertical shafts 16 and the right and left rotational vertical shafts 16. Arc-shaped stirring blade 24
The protrusion length in the horizontal direction is 1/2 of the interval between the vertical rotational shafts 16
However, since the mounting phases of the arcuate stirring blades 24 on each rotating vertical shaft 16 are shifted by 90 degrees, the stirring blades 24 rotate without interfering with each other. At the same time, the rotation trajectories of the arc-shaped stirring blades 24 partially overlap with each other.

The same holds true for the plate-shaped stirring blades 26. As shown in FIG. 3B, the installation phase of the plate-shaped stirring blades 26 is shifted by 90 degrees on each axis, so that the plate-shaped stirring blades 26 that protrude more than half the shaft spacing do not interfere with each other. Rotate. Further, their rotation trajectories partially overlap each other.

The rotating vertical shaft 16 is hollow, and the inside thereof becomes a feeding path for cement, mortar, or other solidifying material, and the solidifying material pumped here is transferred to each rotating vertical shaft 1.
The nozzle portion 28 of No. 6 projects outward. The nozzle part 28 is provided near the bit 22,
Consolidation material is injected outward from here.

Next, the operation and effect of the above configuration will be explained.
The stirring and mixing device 14 according to the present invention is installed vertically on the support device 12, and the cart 10 is moved and fixed at a predetermined position. In this state, the entire device 14 is pressed downward while rotating the three rotary vertical shafts 16.
Then, the ground is excavated with bit 22, and the vertical axis of rotation 1
6 can be inserted to an appropriate depth. Here, the rotary vertical shaft 16 is rotated to excavate the earth and sand while force-feeding the compacting material to the device 14, and injecting the compacting material from the nozzle portion 28.

The plate-shaped stirring blades 26 installed laterally stir and flow the excavated soil mainly in the vertical direction. Further, the arc-shaped stirring blades 24 installed in the vertical direction stir and flow the excavated soil mainly in the horizontal direction. Also, each wing 2 of each axis 16
Since the rotational trajectories of the blades 4 and 26 partially overlap each other, the areas around the moving parts of the blades 24 and 26 are uniformly agitated over a very wide range. Nozzle part 2
The consolidating material injected from 8 is scattered around by the arcuate stirring blades 24 and uniformly supplied to the voids within the effective stirring area. The supplied solidifying material is uniformly mixed with the excavated earth and sand by the rotation of the stirring blades 24 and 26. The earth and sand containing the solidifying material are efficiently stirred and mixed three-dimensionally in the vertical, horizontal, and diagonal directions by the respective stirring blades 24 and 26. Moreover, the effective stirring area is continuous around the three rotating vertical shafts 16, 16, 16, and a wide range in the horizontal and vertical directions can be efficiently stirred and mixed at once.

This mixing and stirring of the consolidation material and excavated soil is
The rotating vertical shaft 1 is rotated while discharging the solidified material from the nozzle 28.
Do this also when pulling out 6.

Then, the hardening material hardens over time,
Column piles are formed in the ground.

FIG. 4 shows a second embodiment of the invention. The difference from the first embodiment shown in FIG. 2 is that each rotational vertical axis 16
The point is that arc-shaped stirring blades 24 are attached in two stages, upper and lower. In other words, two pieces make up a set of arc-shaped stirring blades 2.
4 are mounted above and below at regular intervals, and their mounting angles are also 180° different. These arcuate stirring blades 24 can rotate without interfering with each other, and their rotation loci also partially overlap with each other.

According to the embodiment shown in FIG. 4, since the attachment area of the stirring blades 24 and 26 is expanded in the vertical direction, the area where stirring and mixing can be performed at one time is expanded in the depth direction.

FIG. 5 shows a third embodiment of the present invention. In this embodiment, four vertical rotating shafts 16 are provided, and the mounting positions of the arc-shaped stirring blades 24 are shifted vertically every other shaft. By shifting the mounting positions of the arcuate stirring blades 24 up and down in this way, the stirring blades 24 having large outer diameters can rotate without mutual interference.

In addition, in FIG. 5, the lower end positions of the four rotating vertical shafts 16 are aligned, and each bit 22 is placed at the same position.
is installed. Therefore, the outer diameter of each bit 22 is made small to prevent mutual interference.
Therefore, the excavation cross-sections of each bit 22 no longer overlap as in the previous embodiment. In order to compensate for this, auxiliary bits 30 are installed just above the bits 22 at alternate positions vertically shifted. The protrusion length of this auxiliary bit 30 is greater than 1/2 of the distance between the axes, and their rotation loci partially overlap each other in a plane.

If the number of rotating vertical shafts 16 is increased as in the embodiment shown in FIG. 5, the effective area in which stirring and mixing can be performed at one time can be greatly expanded in the horizontal direction, and work efficiency can be further improved.

<<Effects of the invention>> As explained in detail above, the excavation stirring and mixing device for forming columnar piles according to this invention is achieved by combining the plate-shaped stirring blades in the horizontal direction and the arc-shaped stirring blades in the vertical direction. In addition to expanding the effective stirring area in the vertical direction, by providing multiple rotating vertical shafts, the effective stirring area can also be greatly expanded in the horizontal direction, making it easier to mix and mix compacted material and excavated soil. This process can be carried out very efficiently and effectively, and as a result, the strength of column piles formed by hardening of the consolidation material can be made uniform.

[Brief explanation of the drawing]

1A and 1B are a front view and a side view schematically showing the device according to the first embodiment of the present invention attached to a support device; FIG. 2 is an enlarged partial front view of the device according to the first embodiment;
Figure 3 A, B, and C are views from arrow A in Figure 2, and B
3D is a plan view showing the cross-sectional shape of excavation by the device of the first embodiment, FIG. 4 is a partial front view of the device of the second embodiment of the present invention, and FIG. FIG. 3 is a partial front view of a device according to a third embodiment of the present invention. DESCRIPTION OF SYMBOLS 10... Trolley, 12... Support device, 14... Excavation stirring mixing device for column pile formation, 16... Rotating vertical shaft, 18... Bearing holder, 20... Drive mechanism, 2
2... Bit, 24... Arc-shaped stirring blade, 26... Plate-shaped stirring blade, 28... Nozzle part, 30... Auxiliary bit.

Claims (1)

[Scope of utility model registration request] A plurality of rotating vertical shafts are supported in parallel at predetermined intervals and driven to rotate, an excavation bit is attached to the lower end of each rotating vertical shaft, and a drilling bit is arranged vertically around the lower part of each rotating vertical shaft. plate-shaped stirring blades installed in the horizontal direction above and below the arc-shaped stirring blades on each vertical axis of rotation; and plate-shaped stirring blades installed near the arc-shaped stirring blades on each vertical axis of rotation. and a nozzle portion for discharging the consolidated material under pressure into the feed passage in each rotating vertical shaft, and the arc-shaped stirring blade and the plate-shaped stirring blade of each rotating vertical shaft rotate without interfering with each other. 1. An excavation stirring and mixing device for forming columnar piles, characterized in that the rotary trajectories of the blades partially overlap with each other in a plane.