JPH0489914A - Agitation device for deep layer mixing - Google Patents

Abstract

PURPOSE:To perform operation without damaging an agitating device and eventual obstacle in a place adjoining to the obstacle, by forming agitation blades with flexibility which enables deformation backward in the rotating direction. CONSTITUTION:An agitating device for deep layer mixing comprises an agitating shaft 10, which is inserted in the ground and rotated, and agitation blades 12, 12 mounted on this agitating shaft 10. These blades 12, 12 are formed, for example, from a plurality of laminated leaf springs 20, 20 having different lengths, and thereby provided with flexibility which enables deformation backward in the rotating direction. Accordingly even when operation is made in a place adjoining to any existing structure or steel sheet piles, eventual touching of the blades 12, 12 with such obstacle will not cause damage to the agitating device as well as the obstacle.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a stirring device for deep mixing treatment.

(Conventional technology) The deep agitation mixing method, which is a type of ground improvement, penetrates the ground while rotating a stirring shaft equipped with stirring blades.While stirring the ground with the stirring blades, cement milk, etc. is pumped from the stirring shaft. This is a method of injecting compacting material to form column-shaped compacts in the ground.

As a stirring device for deep mixing treatment used in this type of construction method, for example, as disclosed in Japanese Utility Model Application Publication No. 63-14633, a device in which plate-shaped stirring blades are fixed to the outer periphery of a stirring shaft is used. Generally adopted.

However, the stirring device having such a structure has the following technical problems, especially when the ground area to be improved is adjacent to an existing structure or a steel sheet pile for earth retention.

(Problem to be Solved by the Invention) In other words, in the conventional stirring device described above, the stirring blades are fixed to the stirring shaft, so when attempting to improve the ground in an area that is in contact with an existing structure or steel sheet pile, the stirring There is a problem that the blades may come into contact with the underground foundations or steel sheet piles of existing structures, causing deformation of the foundations or steel sheet piles, or causing damage or deformation of the stirring shaft. It was not possible to improve the ground in the area adjacent to the area.

This invention was made in view of these conventional problems, and its purpose is to eliminate underground obstacles such as existing structures and steel sheet piles adjacent to the ground area to be improved. Another object of the present invention is to provide a stirring device for deep mixing processing that enables stirring for deep mixing processing.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a deep mixing process comprising a stirring shaft penetrated into the ground and driven to rotate, and a stirring blade attached to the stirring shaft. The stirring device is characterized in that the stirring blade has flexibility so that it can be deformed toward the rear side in the rotation direction.

The stirring blades can be constructed from a plurality of laminated leaf springs of different lengths.

(Function) According to the stirring device for deep mixing processing having the above configuration, since the stirring blade has the flexibility to be deformed toward the rear side in the rotation direction, the stirring blade can rotate steel sheet piles, etc. When it comes into contact with an obstacle, it deforms and prevents damage to both.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 and FIG. 2 show an embodiment of a stirring device for deep mixing treatment according to the present invention.

The stirring device for deep mixing treatment shown in the figure is composed of a stirring shaft 10 that penetrates into the ground and is driven to rotate, and stirring blades 12 attached to this stirring shaft 10.
is provided with a spout hole 13 for consolidating material on its outer periphery.

In this embodiment, a pair of the stirring blades 12 having the same configuration are provided at opposing positions with respect to the stirring shaft 10.

Each stirring blade 12 is fixed to a mounting base 14 fixed to the outer periphery of the stirring shaft 10 by screwing bolts 18 through a holding plate 16. In this embodiment, each stirring blade 12 has a curved length. It is composed of four different leaf springs 20.

The leaf springs 20 are located on the outside in order of length, and are curved toward the rear with respect to the rotational direction of the stirring shaft 10, and are deformed toward the rear with respect to the rotational direction. However, it is designed not to deform in the direction of rotation.

As the material of the leaf spring 20, thin metal, synthetic resin, hard rubber, etc. can be used.

In the stirring device for deep mixing treatment configured as above,
When constructing ground improvement in an area adjacent to obstacles such as steel sheet piles or underground foundations, the stirring g12 has flexibility that can be deformed toward the rear side in the rotational direction of the rotating shaft 10. Therefore, when the stirring blade 12 comes into contact with an obstacle such as a steel sheet pile while rotating, it deforms and prevents damage to both.
It can be rotated and a column-shaped solid body with a cross-sectional shape slightly deformed from a circular shape can be created in the ground.

In addition, in the above embodiment, a pair of stirring blades 12 are attached to the stirring shaft 10 at equal angular intervals, but the implementation of the present invention is not limited to this, and stirring blades 12 having the same configuration may be used.
Three or more E12 may be provided on the stirring shaft 10 at equal angular intervals, or may be provided on the stirring shaft in a multistage manner.

(Effects of the Invention) As described above in detail in the examples, the stirring device for deep mixing treatment according to the present invention allows ground improvement in areas adjacent to obstacles such as existing structures and steel sheet piles. The particular advantage is that this is possible without damaging both the obstruction and the stirring device.

[Brief explanation of drawings]

FIG. 1 is a plan view of a stirring device for deep mixing according to the present invention, and FIG. 2 is a perspective view of the same device. 10... Stirring shaft 12... Stirring blade 13... Injection hole 20... Leaf spring

Claims (2)

[Claims] (1) In a stirring device for deep mixing processing, which consists of a stirring shaft that penetrates the ground and is driven to rotate, and a stirring blade attached to the stirring shaft, the stirring blade is deformable toward the rear side in the rotation direction. A stirring device for deep mixing processing characterized by having flexibility. (2) The stirring device for deep mixing treatment according to claim 1, wherein the stirring blade is composed of a plurality of laminated leaf springs having different lengths.