JPS63297623A - Method and apparatus for constructing soil continuous column-line wall - Google Patents

Abstract

PURPOSE:To raise the efficiency of operation by increasing mixing and agitating abilities by a method in which excavation and stirring are made while injecting an improving agent slurry, and a stirrer whose excavating head is inversely turned is set and operated before and after the excavating agitating operations. CONSTITUTION:Three rotary shafts 5, 6, and 7 having stirring blades 12 and 13 are turned by a motor 3. An inner tube 6a is coaxially set in the central shaft 6 and connected through a swivel joint to an improving agent-introducing tube 4 and turned by a motor 3a. An entrance 15 for improving agent and an excavating head 14 are provided for the tip of the inner tube 6a, and excavating heads 11 are also provided for the tips of left- and right-side shafts 5 and 7. The head 14 and the heads 11 are designed to mutually turn reversely. The mixing operation can thus be performed in a tight condition without forming cavity in the excavated soil.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention involves injecting a soil improving material such as cement milk and mixing the soil improving material with earth and sand when constructing an underground structure to support a building. Concerning the creation of a soil-column continuous wall by mixing and stirring.

[Conventional technology]

When constructing such a soil-column continuous wall, it is important that the soil improvement material and the excavated soil are mixed and stirred uniformly over the entire improved ground. A widely used method is to mix and stir by rotating an attached propeller-like stirring blade.

However, in this method using stirring blades,
It is known that, depending on the ground, there is a drawback that non-uniform mixing with cement milk occurs due to the co-rotation phenomenon in which the earth and sand and the stirring blades rotate together.

In order to eliminate this drawback, the applicant of the present application proposed a system in which multi-stage stirring blades rotating in opposite directions are provided on the rotating shaft of the mixing/stirring machine, and thereby the excavated soil is mixed in reverse. It was disclosed in the specification of the application no. In this method, as shown in Fig. 5 (I), a mixing/stirring device A having multi-stage stirring blades a, b, and c is used to inject slurry-like improving material from the tip, while (■), ( I
The improved soil E shown in (V) is obtained by processing as shown in II) and (rv).

[Problem that the invention seeks to solve]

The present invention aims to further improve the efficiency of soil improvement by utilizing the ability of the agitator having the above-mentioned counter-rotating multi-stage stirring blades to mix and stir excavated soil and a soil improvement material.

[Means for Solving the Problems] The present invention provides that the function of stirring the soil and mixing the added cement milk into the soil of the agitator having the counter-rotating multi-stage stirring blades is achieved by using the lower earth and sand shearing blades. It was completed based on the knowledge that by rotating in opposite directions, the shearing and stirring action of the earth and sand can be propagated in an expansive manner, and the effects of mixing and stirring can be exerted over a wide range.

As a device for carrying out this method, it is possible to use a device in which a stirrer having counter-rotating multi-stage stirring blades and each stirrer placed before and after the stirrer are integrated by a connecting member.

The agitator integrally connected before and after the multi-stage reversing blade agitator may be a stirrer having ordinary multi-stage rotating agitating blades that rotate in one direction, or a multi-stage reversing blade agitator placed in the center. By using a similar multi-stage counter-rotating blade stirrer, the stirring and mixing effect is increased.

Furthermore, in order to provide sufficient torque to multiple blades, these agitators are usually driven by separate drive sources, but if equipment conditions permit, it is possible to use a common drive source for the rotary blades of each agitator. It is also possible to

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be specifically described below based on the accompanying drawings. In this embodiment, an example is shown in which the apparatus 100 used in the construction method of the present invention is a stirrer in which the stirrers arranged before and after the multi-stage reversing blade stirrer have multi-stage blades rotating in one direction.

When implementing the construction method of the present invention, the mixing/stirring device 100 is connected to a well-known piling tower by a support l. 2 indicates a base integrated with the support 1,
Mounted on the base 2 are motors 3 and 3a for rotating three-speed rotating shafts, respectively, and an inlet pipe 4 for a soil improving material. As shown in FIG. 2, the motor 3 is arranged on the back of the base body 2, and its rotational driving force is transmitted to rotating shafts 5, 6.7 whose upper ends are rotatably supported by the base body 2. In addition,
A transmission system from the motor 3 is provided with a transmission device 8 having a speed reduction function such as a gear train.

Incidentally, the motor 3a is provided on the upper part of the base body 2 in order to rotationally drive an inner tube to be described later.

The rotating shafts 5, 6.7 are rotatably supported by support rods 9.10 at two locations, one midway and near the lower end. As shown in FIG. 3, these support rods 9 and 10 are made up of half-split plates 10a and 10b arranged so as to surround each rotating shaft 5, 6.7 via a sleeve 10c. It is held without falling off by an engagement structure such as a stepped portion between it and the rotating shaft 5°6.7. Each support rod 9, 10 functions as a sleeve for the rotating shaft 5.6.7, and maintains a parallel posture so that the relative positions of these rotating shafts 5.6.7 do not change.

A digging rod 11 having a blade is integrated at the lower end of each of the left and right rotating shafts 5 and 7, and stirring blades 12 and 13 are provided at the upper level, respectively.

The central rotating shaft 6 has a double-tube structure in which an inner tube 6a is coaxially arranged, and the inner tube 6a is communicatively connected to the introduction tube 4 via a swivel joint (not shown) or the like. Ru. In addition, at the lower end of the inner pipe 6a, a cutting tool 1 with a blade is attached.
4, and a spout 15 for supplying the soil improvement material supplied from the introduction pipe 4 into the stake tag. Incidentally, stirring blades 12.13 are provided around the rotating shaft 6 similarly to the left and right rotating shafts 5.7. Here, the inner tube 6a is rotationally driven independently of the rotating shaft 6, and is coaxially and directly connected to a motor 3a as a drive source. Therefore, the inner tube 6a can be driven to rotate in the opposite direction to the rotating shaft 6, and the stirring blades 12 and the excavation head 14 can be set to rotate in opposite directions.

FIG. 4 is a diagram showing the relationship in the rotational direction of the stirring blade 11 at the lower end of each rotating shaft 5.7 and the excavating rod 14 at the lower end of the rotating shaft 6 shown in FIG. As shown in the figure,
It is necessary that the rotating directions of the stirring blade 11 for shearing and the excavating rod 14 at the lower end of each are opposite to each other, thereby improving the shearing efficiency of the soil and the stirring effect.

However, the blades 12 mounted above each of the rotating shafts 5, 6.7 shown in FIG. Rotating in opposite directions can further increase the stirring effect.

In the above configuration, the improvement material slurry supplied from the inner pipe 6a of the rotating shaft 6 is supplied to the soil from the spout 15. In other words, the improvement material slurry is injected and mixed into the soil cut by the shearing stirring blade 11 and the excavation head 14, and the improvement material is raised and mixed by the upper stirring blades 12 and 13 to improve the soil quality in the cutting hole. do.

In the present invention, it is desirable that the stirring areas by the stirring blades 12.13 attached to the rotating shafts 5.6.7 overlap each other. Further, in order to propagate the mixed state of the improvement material slurry by the stirring blades 12.13 of the central rotating shaft 6 to the stirring area by the stirring devices arranged in front and behind, it is necessary to The stirring blades 12.13 are arranged at a higher level than the excavation head 14 of the central rotating shaft 5 and the stirring blades 12.13, and the excavating rods 11 are attached to the rotating shafts 5.7 arranged on both sides, respectively. and the respective rotational surfaces formed by the stirring blades 12.13 are located at a higher position than the rotational surfaces formed by the excavation head 14 of the central rotating shaft 6 and the stirring blades 12.13.

As a result, compared to conventional multi-stage rotary blades that rotate in the same direction, there is no cavity created by the cutting soil being rotated in the same direction, and mixing can be performed in a completely dense state, making it more efficient. The improvement material slurry can be mixed well.

〔Effect of the invention〕

According to the present invention, mutually counter-rotating mixing and
By forming an agitated layer, a method that prevents the excavated soil from co-rotating and achieves uniform mixing with the modifying material over the entire excavated area can be performed simultaneously over a wide range of areas. The effect is that it is possible to form continuous row walls with high efficiency.

[Brief explanation of the drawing]

FIG. 1 shows the overall configuration of an apparatus for carrying out the construction method of the present invention, FIG. 2 is a side view of the base portion, and FIG. 3 shows the arrangement of the rotating blades. FIG. 4 is a diagram showing the rotational relationship between the stirring blade for downward shearing and the excavation head, and FIG. 5 is a diagram showing a construction mode using the previously proposed multi-stage counter-rotating blade. 1: Support body 2: Base body 3, motor 4; Introductory pipe 5.6, 7: Rotating shaft 8: Transmission device 9.10: Support rod 11: Excavation head 12.13
: Stirring blade 14: Drilling head 15: Outlet 100: Mixing/stirring device

Claims (1)

[Scope of Claims] 1. In a ground improvement method in which the excavated ground is mixed and stirred by a stirring blade while injecting improvement material slurry, a rotating shaft is provided with multiple stages of stirring blades, and each of the same multiple stages of stirring blades is A continuous column row of soils is characterized in that further stirrers are arranged before and after the multi-stage reversing blade stirrer that rotates in opposite directions, and the rotation directions of the lower stirring blades of each stirrer are rotated in opposite directions. Wall construction method. 2. A multi-stage reversing blade stirrer, which has multiple stages of stirring blades with different rotational directions on a rotating shaft with an improving material slurry inlet at the tip, is further characterized in that a stirrer is integrally connected before and after the rotary shaft. A continuous wall device with continuous soil columns. 3. The soil connected column column continuous wall according to claim 2, characterized in that the agitators integrally connected before and after the multi-stage reversing blade agitator are agitators having unidirectionally rotating agitating blades. Device. 4. The soil-column continuous wall device according to claim 2, wherein the agitators integrally connected before and after the multi-stage reversing blade agitator are multi-stage reversing blade agitators.