JPS61229015A - Method and device for improving ground - Google Patents

Abstract

PURPOSE:To form a solid solidified column, by a method wherein a ground is excavated as high pressure fluid is injected through a high speed rotating agitating tool, and excavated soil and a soil stabilizing agent are mixed and agitated as the soil stabilizing agent is poured in the excavated soil with the aid of the high speed rotating agitating tool. CONSTITUTION:With a rotary shaft 10 rotated through driving of a driving device 6, an agitating tool 14 is lowered into excavated soil, and after a ground is excavated in the shape of a column through injection of high pressure fluid through an injection port 16, the agitating tool 14 is pulled out. The agitating tools 14 in plural stages are lowered in the excavated soil as they are rotated at a high speed, a soil stabilizing agent is poured into the excavated soil through discharge ports 18, and the excavated soil and the soil stabilizing agent are mixed together to form a solidified column.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a soil improvement method and device used when constructing consolidation columns underground for soil improvement, and in particular, to The present invention relates to a ground improvement method and its device that can perform columnar excavation, reduce the size and weight of the device, achieve good stirring and mixing, and create solid consolidation columns.

[Conventional technology] In order to improve unstable ground, the ground is excavated using a rotating excavator, and a soil stabilizer (e.g., cement milk, water glass, etc.) is injected into the excavated soil to stabilize the excavated soil and soil quality. A construction method and an apparatus for creating a consolidation column in the ground by stirring and mixing the agent and the soil in the ground are known.

[Problems to be solved by the invention] However, in conventional construction methods and equipment, for example, the excavation shaft equipped with a digging tool for excavating the ground and the stirring shaft equipped with a stirring tool for stirring and mixing are separately provided. It was supported on pillars so that it could be raised and lowered. Alternatively, digging tools and stirring tools were centrally arranged on a rotating shaft that was supported on a support so that it could be raised and lowered. This complicates the structure, leading to an increase in size and weight, and the former also has the disadvantage of requiring a large work space during work. Furthermore, during excavation, the rotation speed of the drive device was reduced in order to obtain a large excavation torque. For this reason, if you try to excavate at high speed, 1. This results in a lack of torque, and in order to eliminate the lack of torque, a large drive device with a large driving force must be provided, resulting in an increase in the size and weight of the device.

[Purpose of the Invention] Therefore, the present invention solves these problems, makes it possible to excavate the ground at high speed without increasing the size or weight of the device, and reduces the size and weight by simplifying the structure. The purpose of this invention is to realize a soil improvement method and equipment that can achieve good stirring and mixing.

[Means for Solving the Problems] In order to achieve this object, the present invention excavates the ground in a columnar manner while ejecting high pressure fluid from a stirring tool that rotates at high speed, and then excavates the ground in a columnar manner into the excavated soil at a high speed. The method is characterized in that the excavated soil and the soil stabilizer are stirred and mixed while injecting the soil stabilizer with a stirring tool, and the stirring tool is provided at the tip of a rotating shaft that rotates at high speed and is supported by a support that can be raised and lowered. In addition, this stirring tool is characterized in that it is provided with a high-pressure fluid jet port and a soil stabilizer discharge port.

[Operation] According to the present invention, the ground is first excavated in a columnar manner and disturbed while jetting high-pressure fluid from the spout of the stirring tool that rotates at high speed and is provided at the tip of the rotating shaft. Next, the soil stabilizer is injected into the excavated soil excavated with this high-pressure fluid from the discharge port, and the excavated soil and soil stabilizer are stirred and mixed with a stirring tool that rotates at high speed, thereby creating consolidation columns in the ground. are doing. Therefore, there is no need to separately provide an excavating tool or a shaft for rotating the excavating tool as in the conventional case, and the ground can be excavated by high-speed rotation.

[Example] Next, embodiments of the present invention will be described in detail based on the drawings.

In the figure, 2 supports and moves the column 4!
-It is a self-propelled vehicle with one tab. 6 is a hydraulic or electric drive device, which is suspended from the upper end of the support column 4 so as to be able to rise and fall;
Further, it is held by a support 8 via a holding guide 8 so as to be able to move up and down. 1o is a rotating shaft extending in the vertical direction, and its upper end is interlocked and connected to the drive device 6. This rotating shaft 10
The lower part of the column 4 is rotatably held by a steady rest 12 provided at the lower part of the column 4, and a stirring tool 14 is provided at the lower tip.

As shown in FIGS. 2 and 3, the stirring tools 14 are symmetrically provided on both sides of the rotating shaft 10 and protrude substantially horizontally, and are provided in multiple stages. A plurality of spout ports 16 for high-pressure fluid (for example, pressurized water, compressed air, etc.) and a plurality of discharge ports 18 for soil stabilizer are provided on the lower surface side of the stirring tool 14 and on the front side in the direction of rotation indicated by arrow a in FIG. They are installed in parallel. The spout 16 blows out high-pressure fluid when excavating the ground to excavate the ground in a columnar manner,
The discharge port 18 injects the soil stabilizer during stirring. Note that the direction, number, arrangement position, etc. of the jet ports 16 are not limited to the illustrated example, and for example, they may be provided at the tip of the stirring tool 14 as shown in FIG. 4, or they may be provided over the entire surface of the stirring tool 14. They may be arranged randomly. Alternatively, the ejection port 16 and the discharge port 18 may not be provided separately, but may be the same hole, and a supply passage may be provided so that the high-pressure fluid and the soil stabilizer can be selectively ejected. Note that the supply passages for these high-pressure fluids and soil stabilizers are arranged within the rotating shaft 10.

When stirring and mixing the excavated soil and the soil stabilizer using the stirring tool 14, the rotation is performed in order to improve the stirring and mixing, such as preventing leakage of the soil stabilizer to the outside or increasing the strength after construction. The shaft 10 is rotated at high speed (80 revolutions/minute or more).

At this time, stirring and mixing does not require a large torque as in the case of excavation, so the torque of the drive device 6 is reduced to obtain high-speed rotation. Since the ground is excavated in a columnar manner and disturbed by the high pressure fluid ejected from the spout 16 of the stirring tool 14 which rotates at high speed, the excavation can be performed well and at high speed.

Next, this invention will be explained in detail.

The self-propelled vehicle 2 with caterpillars is run, and the entire device is installed at a predetermined position where a consolidation column for ground improvement is to be constructed. Next, the support column 4 is supported substantially perpendicularly to the ground, and the rotating shaft 10, stirring tool 14, etc. supported by the support column 4 so as to be able to rise and fall are erected perpendicularly to the ground. Next, the drive device 6 is driven to rotate the rotating shaft 10, and the rotating stirring tool 14 is lowered to the ground surface (FIG. 5(A)). When excavating the ground, high-pressure fluid, such as pressurized water or compressed air, is ejected from the ejection port 16 of the stirring tool 14. This high pressure fluid
As shown by arrows a-b in the figure, the water is ejected forward in the rotational direction and downward direction of the stirring tool 14 rotating at high speed, excavating and disturbing the ground in a columnar manner (FIG. 5(B)). At this time, in order to immerse the stirring tool 14 into the ground while excavating the ground in a columnar shape, the drive device 6 connected to the upper end of the rotating shaft 10 is lowered along the support column 4 by the holding guide 8. Although the drive device 6 rotates the stirring tool 14 at high speed by reducing the torque,
High-pressure fluid is ejected forward in both the rotating and descending directions of the stirring tool 14 to excavate the ground in a columnar manner and further agitating it to soften it, so the stirring tool 14 can be rotated and lowered without causing a lack of torque even at high speeds. obtain. As a result, even a small drive device with low driving force can be rotated at high speed during excavation, making it possible to reduce the size and weight of the device.

When columnar excavation of the ground using high-pressure fluid progresses and reaches a predetermined depth, the stirring tool 14 stops descending (Fig. 5 (C)).
). After that, the stirring tool 14 and the like are raised on the contrary. At this time, the stirrer 14 is raised while being rotated, but it may be raised while being rotated in the opposite direction to when it is lowered. In addition, by ejecting high-pressure fluid and raising it while rotating, the excavated soil can be further softened to better stir and mix with the soil stabilizer in the subsequent process. Stirring tool 14 from inside the ground
The excavation is completed by extracting the (Fig. 5 (D)
).

Next, the multiple stage stirring tools 14 are rotated at high speed by the drive device 6 and lowered onto the surface of the excavated soil (FIG. 5(E)). When stirring with the stirring tool 14, soil stabilizer (
For example, cement milk, water glass, polymer materials, air mortar, etc.) are injected into the excavated soil. That is, the discharge port 18 is
A plurality of agitators 14 are provided in parallel with the discharge ports 16, and are oriented forward in the rotating direction and descending direction of the agitator 14 shown by arrows a-b in FIG. 4, respectively. Therefore, the stirring tool 14 injects the soil stabilizer in the front and stirs and mixes the soil stabilizer and the excavated soil (FIG. 5(F)). At this time, the stirring tool 14
Since the high torque required for excavation is not required, even a small drive device with low driving force can rotate at high speed,
By providing multiple stages of stirring tools, sufficient stirring and mixing can be achieved, and the device can be made smaller and lighter. In addition, high-speed rotation prevents soil stabilizing material from leaking to the outside.
The strength after construction can be increased.

In this way, while injecting the soil stabilizer into the excavated soil, the stirring tool 1
4 to achieve stirring and mixing, and when a predetermined depth is reached, the stirring tool 14 stops descending (FIG. 5(G)). Next, the stirring tool 14 is raised and pulled out from the ground. At this time,
The stirring tool 14 may be raised while being rotated in the same direction as when it was lowered, or may be raised while being rotated in the opposite direction.

The stirring and mixing is completed by raising the stirring tool 14 and pulling it out from the ground (FIG. 5(H)).

As a result, in the ground after stirring tool 14 is removed,
Consolidation pillars are created.

[Effects of the Invention] As described above, according to the present invention, a high-pressure fluid spout and a soil stabilizing material discharge port are provided in a high-speed rotating agitation tool, and the ground is excavated in a columnar manner using the high-pressure fluid, and then the soil is stabilized. Consolidation pillars are created by stirring and mixing excavated soil and soil stabilizer while injecting material. This eliminates the need for separate excavation tools, shafts for rotating the excavation tools, and even excavation drive devices, which was required in the past, and together with the simplification of the structure, the equipment can be made smaller and lighter, as well as faster. can excavate the ground. In addition, the high-speed rotating stirring tool provides good stirring and mixing, prevents soil stabilizer from leaking to the outside, and increases the strength after construction.

[Brief explanation of drawings]

The figures show an embodiment of the invention, in which Fig. 1 is an overall side view of the device, Fig. 2 is a side view of the stirring tool, Fig. 3 is a bottom view of the stirring tool, and Fig. 4 is a perspective view of the stirring tool. FIGS. 5(A) to 5(H) are explanatory diagrams showing the steps. In the figure, 4 is a column, 6 is a drive device, 10 is a rotating shaft,
14 is a stirring tool, 16 is a spout, and 18 is a discharge port.

Claims (1)

[Scope of Claims] 1. Excavate the ground in a columnar manner while ejecting high pressure fluid from a stirring tool that rotates at high speed, and then excavate the excavated soil while injecting a soil stabilizer into the columnar excavated soil using the stirring tool that rotates at high speed. A ground improvement method characterized by stirring and mixing the soil stabilizer and the soil stabilizer. 2. Ground improvement characterized in that a stirring tool is provided at the tip of a rotating shaft that rotates at high speed and is supported by a support that can be raised and lowered, and the stirring tool is provided with a high-pressure fluid spout and a soil stabilizer discharge port. Device.