JPS6117631A - Method and apparatus for improving ground - Google Patents

Abstract

PURPOSE:To prevent the lowering of the strength of the ground by a method in which the ground is excavated by an excavator being turned at low speed, the excavator is drawn out, and a soil stabilizer is injected and mixed with excavated soil by a stirrer being turned at high speed. CONSTITUTION:A driver 12 is operated to turn an excavating shaft 20 at low speeds, and the ground is excavated by rotation of an excavator 26. The driver 12 is lowered along a strut 10 by a guide 16. When the excavation is made to a given depth, the excavator 26 is raised and drawn out of the ground. A stirrer 34 is turned at high speeds by a driver 14 and penetrated into the ground, and the driver 14 is also lowered along the strut 10 by a guide 18. A soil stabilizer is injected from a nozzle 36 into the excavated soil and mixed with the excavated soil by the stirrer 34.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to improvements in a soil improvement method and equipment used when constructing consolidation columns underground for soil improvement, etc. The present invention relates to a ground improvement method and device that can simplify the process, reduce weight, and achieve good mixing and agitation.

[Prior Art] In order to improve unstable ground, the ground is excavated using a screw with a head provided at the tip of a rotating shaft, and a soil stabilizer (for example, cement milk, water glass, etc.) is applied to the tip of the shaft. A construction method and an apparatus for creating a consolidation column in the ground by pouring excavated soil and a soil stabilizer into the ground and stirring and mixing them underground are known.

[Problems to be Solved by the Invention] By the way, in conventional construction methods and equipment, in order to stir and mix while excavating, for example, an excavator, a stirring tool, and a soil stabilizer are disposed at the tip of the rotating shaft. Some have an exit etc. However, in the past, the excavating tools and the like were arranged in a concentrated manner, resulting in a complicated structure and a heavy weight. Moreover, when attempting to obtain the required excavation torque by reducing the rotation speed of the drive device to rotate these heavy excavation tools during ground excavation, the reduction in rotation speed requires a long time for stirring and mixing, and the soil quality There is an inconvenience that the stabilizer leaks to the outside,
Poor stirring may also occur. Therefore, in order to obtain large torque and high speed rotation, it is necessary to provide a large-sized drive device with a large driving force, resulting in the inconvenience of increasing the size and weight of the entire device.

Alternatively, there is a method in which a stirring tool that rotates at high speed is placed above the excavating tool that has a discharge port for the soil stabilizer, and this stirring tool is rotated around the excavation shaft along with the rotation of the excavating tool, but this method also has a different structure. Because it is complex, it is also heavy. For this reason,
It had the above-mentioned disadvantages.

[Object of the Invention] Therefore, it is an object of the present invention to solve such problems, to realize a soil improvement method and an apparatus thereof that can simplify the structure, reduce the weight, and achieve good stirring and mixing.

Means for Solving Problem E] To achieve this object, the present invention excavates the ground with a low-speed rotating excavation tool, and after removing the excavation tool, injects a soil stabilizer into the excavated soil, Thereafter, the excavated soil and the soil stabilizer are stirred and mixed by a stirring tool that rotates at high speed, and the digging tool is provided at the tip of an excavation shaft that rotates at a low speed and is supported by a support that can be raised and lowered. The present invention is characterized in that a soil stabilizer discharge port and a stirring tool are provided at the tip of a stirring shaft that is supported by the pillar so as to be able to rise and fall and rotates at high speed in parallel with the excavation shaft.

[Operation] As described above, according to the present invention, the ground is first excavated with a low-speed rotating excavator, and when the excavation reaches a predetermined depth, the excavator is removed. Next, a soil stabilizer is injected into the excavated soil from a discharge port provided at the tip of a stirring shaft that rotates at high speed in parallel with the excavation shaft, and the excavated soil and soil stabilizer are stirred and mixed with a stirring tool that rotates at high speed. , Consolidation pillars are created in the ground.

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

In the figure, 2 is a self-propelled vehicle with caterpillars that supports and moves the holding column 4. Reference numeral 6 denotes a support that is suspended from the upper end of the holding column 4 by a support cable 8 so as to be able to rise and fall freely, and a column 10 is suspended from this support 6. In addition, the support 6 includes
An excavation drive device 12 and a stirring drive device 14, which are hydraulic or electric, are each suspended so as to be able to rise and fall. The excavation drive device 12 and the stirring drive device 14 are held on both sides of the column 10 by holding guides 16 and 18, respectively, so as to be able to rise and fall.

The upper end portion of an excavation shaft 20 extending in the vertical direction is interlocked and connected to an excavation drive device 12 provided on one side of the pillar 10 so as to be movable up and down. The excavation shaft 20 is rotated at a low speed (60 rotations/minute or less, preferably 10 to 30 rotations/minute) by the excavation drive device 12 for reasons to be described later. The lower part of this excavation shaft 20 is held by a steady rest 22 provided at the bottom of the column 10, and furthermore, an excavation blade 24 is provided at the lower tip.
A cutting tool 26 is provided, and a cutting blade 2 is provided at the lower end.
There are 8. The excavating tool 26 is provided on both sides of the excavating shaft 20 so as to project upwardly. This drilling tool 2
6, when excavating the ground, the rotational speed of the excavation drive device 12 is reduced to obtain a large torque in order to obtain the required excavation torque.

An upper end portion of a stirring shaft 30 extending in the vertical direction is interlocked and connected to a stirring drive device 14 provided on the other side of the support column 10 so as to be able to move up and down. The stirring shaft 30 is provided with its axial direction parallel to the axial direction of the excavation shaft 20. The lower part of the stirring shaft 30 is held by a steady rest 32 provided at the lower part of the column 10, and a plurality of stages of stirring tools 34 are protruded substantially horizontally from both sides of the stirring shaft 30 at the lower tip. A soil stabilizer discharge port 36 is provided below each stirring tool 34. In this OJJ, in order to pour out the soil stabilizer into the excavated soil from the opening 36, the stirring tool 34 has a hollow cylindrical shape and communicates with the stirring shaft 30, forming a passage for supplying the soil stabilizer. ing. In this embodiment, the stirring tool 34 is provided with a discharge port 36 to have a stirring/discharging function, but a separate discharge port is provided and communicated with the passage for supplying the soil stabilizer, thereby separating the discharge port from the stirring tool 34. You can also do it.

When stirring and mixing the excavated soil and the soil stabilizer using the stirring tool 34, the stirring 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 30 is rotated at high speed (60 to 150 revolutions/minute). At this time, stirring and mixing does not require a large torque as in the case of excavation, so the torque of the stirring drive device 14 is reduced to obtain high-speed rotation.

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 supports the support column 10 substantially perpendicularly to the ground, and the excavation shaft 20 is supported by the support column 10 so as to be freely raised and lowered.
The excavating tool 26, stirring shaft 30, stirring tool 34, etc. are erected perpendicularly to the ground.

At this time, first, the excavating tool 26 is installed at a predetermined position where a consolidation column is to be created. Next, the excavation drive device 12 is driven to rotate the excavation shaft 22, and the rotating excavation tool 26 is lowered to the ground surface (FIG. 4(A)). The ground is excavated by the rotation of the excavating tool 26 (FIG. 4(B)). At this time, in order to sink the excavation shaft 20 into the ground while excavating the ground, the excavation drive device 12 connected to the upper end of the excavation shaft 20 is lowered along the support column 10 by the holding guide 16. The excavation drive device 12 outputs driving force by decreasing the rotation speed and increasing the torque so that the required excavation torque can be obtained. Therefore, the excavating tool 26 is rotated at a low speed with a required excavating torque, so that the ground can be reliably excavated. Therefore, the excavation drive device 12 can be a small one with a small driving force, which can contribute to making the device smaller and lighter.

As the excavation by the excavator 26 progresses and reaches a predetermined depth, the descent of the excavator 26 is stopped (FIG. 5(C)).

After that, the excavating tool 26 and the like are raised on the contrary. At this time,
Although the digging tool 26 is raised while being rotated, it may be raised while being rotated in the opposite direction to the direction in which it is lowered. When raising the excavator tool 2, since no torque is required when descending the excavator.
6 can also be rotated at high speed. Excavation is completed by pulling out the excavation tool 26 from the ground (FIG. 4(D)).

Next, the position of the support column 10 is changed using the holding column 4 of the self-propelled vehicle 2 with caterpillars, and the stirring tool 34 is moved to the predetermined position where the consolidation column is to be created.
Set up. The stirring drive device 14 rotates the multi-stage stirring tools 34 and lowers them onto the excavated upper surface of the ground (fourth
Figure (E)). By lowering and rotating the stirring drive device 14, the stirring tool 34 is immersed into the excavated soil. After immersion, outlet 3
6 to soil stabilizers (e.g. cement milk, water glass,
(polymer material, air mortar, etc.) is poured into the excavated soil, and the excavated soil and soil stabilizer are stirred and mixed using a rotating stirring tool 34 (FIG. 4 (F)). At this time, the high torque required for excavation is not required, so even a small drive device with low driving force can be rotated at high speed, and by providing multiple stages of stirring tools, sufficient stirring and mixing can be achieved. It becomes possible to make it smaller and lighter. In addition, high-speed rotation prevents the soil stabilizer from leaking to the outside, increasing the strength after construction.

In this way, the soil stabilizer is poured into the excavated soil and the stirring tool 34
When a predetermined depth is reached, the stirring tool 34 stops descending (FIG. 4(G)). Next, the stirring tool 34 is raised and pulled out from the ground. At this time, the stirring tool 34 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 34 and removing it from the ground (FIG. 4 (H)).

As a result, in the ground after the stirring tool 34 is extracted,
Consolidation pillars are created.

In this embodiment, the soil stabilizer is poured out from the tip of the stirring shaft, but it is also possible to pour it out from the tip of the excavation shaft. Further, by forming the excavating tool in a spiral shape, it can be easily immersed into the ground.

[Effects of the Invention] As described above, according to the present invention, the ground is excavated with a low-speed rotating excavator, and after the excavator is removed, the excavated soil and the soil stabilizer are stirred and mixed with a high-speed rotating agitator. It is possible to excavate the ground reliably and mix it thoroughly. This prevents the soil stabilizer from leaking to the outside, increases the strength after construction, and allows for good stirring and mixing.

Furthermore, in order to achieve the above effects, the excavating tool and the stirring tool are constructed separately and driven to rotate. That is, the excavating tool is rotated at a low speed so as to obtain the required digging torque, and the stirring tool is rotated at a high speed with a reduced torque since high torque is not required during excavation. This simplifies the structure of the excavating tool, stirring tool, etc., and allows rotational driving of each with a small drive device with small driving force, thereby making it possible to avoid increasing the size of the drive device.

Therefore, it is possible to realize an apparatus that can simplify the structure of the entire apparatus, reduce its weight, and perform good stirring and mixing. Furthermore, by forming the excavating shaft or the stirring shaft into a spline shaft and interlockingly connecting it to the drive device using an endless rotation transmitting device such as a chino or a belt, the drive device can be shared. As a result, further weight reduction can be achieved.

[Brief explanation of drawings]

The figures show an embodiment of the present invention, with Figures 1 and 2 being an overall side view and an overall front view of the device, respectively, Figure 3 being an enlarged front view of the main parts, and Figures 4 (A) to (H) showing the process. FIG. 2 is a schematic explanatory diagram showing the order. In the figure, 2 is a self-propelled vehicle with caterpillars, 4 is a holding column, and 6 is a self-propelled vehicle with caterpillars.
10 is a support, 12 is an excavation drive device, 14 is a stirring drive device, 20 is an excavation shaft, 26 is an excavation tool, 30 is a stirring shaft, 34 is a stirring tool, and 36 is a discharge port. Agent Patent attorney Yoshimi Saigo Agent Patent attorney Hara 1) Engraving of Yukio drawing (no changes in content) Figure 1 M2fl Figure 3 Former Figure 4 (A) (B) (C)
(D) (E) (F)
(G) (H) Motion of procedural amendment August 17, 1980 Manabu Shiga, Commissioner of the Patent Office1, Indication of the case, Patent Application No. 137925, filed in 1982,2, Name of the invention, Ground improvement method and device 3 , Relationship with the case of the person making the amendment Patent applicant Address: 3-1-6 Isobe, Chiba City, Chiba Prefecture Name: Hideo Tezawa 4, Agent: 105 Ta 03-438-
2241 (Representative) Address: 3-4-17-5, Toranomon, Minato-ku, Tokyo, Date of amendment order: Voluntary order 6, Drawing subject to amendment (no change in content)

Claims (1)

[Claims] 1. After excavating the ground with a low-speed rotating excavator and removing the excavator, a soil stabilizer is injected into the excavated soil, and then a high-speed rotating stirring tool is used to mix the excavated soil. A ground improvement method characterized by stirring and mixing the soil stabilizer. 2. An excavation tool is provided at the tip of an excavation shaft that rotates at low speed and is supported by a support that can be raised and lowered, and a stirring shaft that is supported by the support that can be raised and lowered and that rotates at high speed in parallel with the excavation shaft is equipped with a soil quality control tool. A ground improvement device characterized by being provided with a stabilizer discharge port and a stirring tool.