JP3175818B2 - Ground improvement device equipped with widening type stirring blade - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement apparatus provided with a widening stirring blade suitably used for a jet stirring method involving mechanical stirring.

[0002]

2. Description of the Related Art As a soil improvement method for a soil with high water content, such as a soft clayey soil or an organic soil, a hardening material such as cement is injected into a target ground, and the hardened material and the soil of the local ground are grounded. In this method, a method of mixing by mechanical stirring to consolidate (hereinafter, referred to as “jet stirring and consolidation method”) is frequently used.

[0003] On the other hand, in recent years, with the overcrowding of underground structures particularly in urban areas, there has been an increasing demand for construction while protecting the lower portion and side portions of existing underground structures. . In the case of the conventional chemical injection method or injection stirring method, the existing buried structure is used to excavate to a predetermined depth by small-diameter boring and then perform horizontal high-pressure jet injection from there to improve the ground Therefore, a jet stirring device having a small pressure effect is desired. At present, as a jet stirrer that can meet this demand,
There is an injection device with a stirring blade used in the so-called SWING method.

[0004]

However, the aforementioned S
The injection stirrer and the like used in the WING method have a problem that the structure is complicated in terms of equipment, the production cost of the injection rod itself increases, and it is not economical.

On the other hand, especially when the ground to be improved is a sludge-like ultra-soft ground or corroded soil, the solidified material jetted with the jet runs away to the outside, so that the solidified material is exactly within a predetermined range. There is also a problem that a ground improvement body cannot be created.

Accordingly, a main object of the present invention is to provide a simple and inexpensive apparatus and to uniformly and effectively mix and stir the injected improved material and earth and sand without adversely affecting the surrounding ground. An object of the present invention is to provide a ground improvement device capable of forming an improved body.

[0007]

According to the present invention, there is provided a ground improvement rod having one end pivotally supported at the rod tip side and the other end rotatably connected to a connection fitting.
A first non-cutting edge rod member, one end to the connecting fitting rotation was
A second non-cutting edge rod-like member rotatably connected to and the other end pivotally supported on the rod base end side, with comprises at least one or more link-type stirring blades made of, prior to the link-type stirring blades
At least one of the two support points for the ground improvement rod is made movable in the rod axial direction by slide driving means,
The link-type stirring blade can be freely opened and closed to the side of the rod by contacting and separating the two support points , and the mounting range of the link-type stirring blade
To the link type stirring blade in the open blade state.
At least one or more improving material injection holes for spraying the improving material
While forming, the improvement material collides with the connection fitting
A reflection plate is provided, and the link type stirring blade is opened.
In both the closed state and the closed state, the reflection plate
And is configured to be parallel to the pad .

[0008] The stirring blade in the ground improvement apparatus of the present invention is a link-type stirring blade made of a rod-shaped member having no cutting blade. Therefore, the portion relating to the stirring blade has a simple structure, so that it is inexpensive as compared with the related art.

In addition, since a reflector is provided on the connection fitting of the link-type stirring blade to cause the injected improved material to collide with the ground, there is no pressure action on the ground outside the improvement range, and the improved material does not run away. Therefore, it is possible to eliminate the adverse effect on the surrounding ground due to the improvement, and to reliably form the improved body within a predetermined range.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a view showing a widened state of the widening type jet stirring apparatus of the present invention, and FIG. 2 is a view showing a closed state of the blade. The jet stirring rod according to the present invention is a rod R having a double pipe structure composed of an inner pipe 1 and an outer pipe 2, and the inner pipe 1 is exposed further forward than a tip of the outer pipe 2 at a tip portion thereof. . The inner tube 1 is movable in the axial direction of the rod, and has a drill bit 1b at the tip thereof, and an injection hole for injecting an improved material such as a solidified material or a hardened material toward a side slightly above the drill bit 1b. 1a is formed.

The movement of the inner tube 1 is performed, for example, by using a rod R
This is performed by the inner tube slide driving means A provided on the head of the helmet. In FIG. 5, the inner pipe slide driving means A
Is provided with a cylinder pipe 20 through which the inner pipe 1 is inserted. By supplying hydraulic oil into the cylinder pipe 20, the inner pipe 1 is hydraulically moved in the rod axis direction. Specifically, the cylinder tube 20 has a double tube structure, and an annular space 20b having an opening at the base end is formed in an outer portion through which the inner tube 1 is inserted. And inner tube 1
An annular piston pipe 22 connected at the base end of the inner pipe 1 and interlocked with the inner pipe 1 is fitted. The general portion of the piston pipe 22 is thinner than the thickness of the annular space 20b, and has a thick portion 22a that slides on a peripheral wall at a tip portion thereof.
0b is partitioned. A swivel 21 is externally fitted to the cylinder tube 20, and working oil is supplied / discharged through the swivel 21. Hydraulic oil supply / discharge ports 21a and 21b are formed in the swivel 21, respectively.
The hydraulic oil supply / discharge port 21a communicates with the base end side of the annular space 20b via an oil supply pipe 23, and the hydraulic oil supply / discharge port 21b communicates with the distal end side of the annular space 20b. Therefore, the inner pipe 1 is moved to the distal end side by supplying the hydraulic oil from the hydraulic oil supply / discharge port 21a and discharging the hydraulic oil from the hydraulic oil supply / discharge port 21b, and vice versa. The inner pipe 1 is moved to the base end side by supplying the working oil from the discharge port 21b and discharging the working oil from the hydraulic oil supply / discharge port 21a. The method of sliding the inner pipe 1 is not limited to the specific example. For example, an existing hydraulic cylinder is connected to the inner end of the rod R such that the inner pipe 1 and the outer pipe 2 are interconnected. It can be arranged and made movable, or it can be made movable by a mechanical driving method. Further, in the relative movement relationship between the inner pipe 1 and the outer pipe 2, the inner pipe 1 is preferably moved, but the movement is not necessarily limited to moving the inner pipe 1; It may be moved.

On the other hand, in the present invention, the rod R is provided with link-type stirring blades W ₀ , W ₁ spanning the inner tube 1 and the outer tube 2. The stirring blade W ₀ includes a first rod-shaped member 4A having no cutting blade having one end pivotally supported on the inner tube 1 side, outside the other end with one end connected to the other end of the first rod-shaped member 4A Second rod-shaped member 4B having no cutting blade pivotally supported on the pipe 2 side
When a more composed pair of stirring blades, the other of the stirring blade W ₁ represents a first rod-shaped member 3A does not have a cutting edge, one end of which is pivotally supported by the inner tube 1 side, the first rod-shaped member 3A A pair of left and right stirring blades each having one end connected to one end and a second rod-shaped member 3B having no cutting blade and having the other end pivotally supported on the outer tube 2 side. The stirring blade W _0, together are arranged perpendicular to the stirring blade W ₁ in a plan view, is located inside of the stirring blade W _1. The rod members 3A, 3B, 4A ...
Although the cross-sectional shape is not particularly limited, a rod-shaped elongated member having a certain degree of rigidity is used. Specifically, a steel material having a square or round cross section is suitably used.

The stirring blades W ₀ and W ₁ will be described in more detail. One end of the first rod-shaped member 4 A of the stirring blade W ₀ is connected to the inner tube 1.
And one end of the second rod-shaped member 4B is pivotally supported on a mounting bracket 5 fixedly mounted on the outer surface of the outer tube 2. And
The other end of the first rod-shaped member 4A and the other end of the second rod-shaped member 4B are rotatably connected to each other via a connection fitting 9 therebetween.

Similarly, the agitating blade W ₁ is also provided with the first rod-shaped member 3.
One end of A and one end of the second rod-shaped member 3B are supported by mounting brackets 7 and 7, respectively, and the other ends are rotatably connected to each other by connecting fittings 9 or 10. Therefore, when the inner pipe 1 is pulled up to the base end side by the inner pipe slide driving means A, the rod-shaped members 3A, 3A
When the supporting points B and 4A and 4B approach each other, the wings are opened as shown in FIG. 1 and the inner pipe 1 is moved to the distal end side, both the supporting members 3A and 3B and 4A and 4B are supported. The points are separated from each other, resulting in a closed wing state shown in FIG.

As the moving means on the other end side of the rod-shaped members 3A, 3B,..., For example, slide driving means shown in FIGS. 6 and 7 can be used. The slide moving means shown in FIG. 6 includes a cylinder 16 inside a single (single tube) rod 15, and fixes the mounting members 7, 7 to a movable member 16a movable by the cylinder 16. The other ends of the two rod-shaped members 3B, 3B are connected, and the movement of the movable member 16a causes the stirring blade W to move.
_One can be opened. The slide moving means shown in FIG. 7 externally fits the slide tube 18 to the rod 17 and externally fits the annular movable member 19, and connects one end of the second rod-shaped member 3B to the annular movable member 19, can be Hirakitsubasa the stirring blade W ₁ by pushing down the slide tube 18 from the ground side. Further, an appropriate position within the provided range of the stirring blade W _0, W _1, is preferably injection holes 1a for injecting modifying material at the center position is formed, the inner tube 1
The improving material fed from the improving material passage 1c formed therein is jetted. In addition, the said injection hole 1a can be formed in multiple numbers along the axial direction of a rod, and can also be formed in multiple numbers around the outer periphery of a rod in order to radiate an improving material radially.

On the other hand, as the improving material injected into the stirring area, a cement slurry using ordinary Portland cement or Class B blast furnace cement is preferably used for cohesive soil. In particular, in the case of targeting an organic soil or a high water content soil (sludge), it is preferable to use an organic soil cement or a high water content soil cement.

The method of jet agitation is appropriately determined in relation to the type of ground.
A method of agitating by ejecting or jetting slurry or the like at 100 kgf / cm ² , or spraying the slurry or the like with a high pressure jet of 200 to 400 kgf / cm ² to forcibly cut and destroy the structure of the surrounding ground and target the ejected slurry. It is possible to arbitrarily select a method of mixing and solidifying with soil, and a method of solidifying by injecting a powdery material such as quicklime, slaked lime, or a polymer. In the case of the high-pressure injection method, as in the case of the JSG method, it is possible to increase the reaching distance by entraining air around the appropriately injected improving material.

The apparatus of the present invention can also provide excellent effects in connection with the high-pressure injection method.
That is, as shown in FIG. 4, the reflecting plate 10a is fixed to the connecting fitting 10 of the stirring blade W _1, impinging been modifying material injected from the injection holes 1a in the reflector 10a. Particularly in the case of loose ground or very soft ground, the injected improved material is prevented from escaping outward as it is, and the stirring blade W
_Since it is left in ₁ and mixed with the agitated earth and sand, the improved body can be formed exactly within a predetermined range. In addition, since there is no pressure action on the surrounding ground, it is easy to perform close construction with the existing structure, and it is possible to prevent the surrounding ground from being raised. Further, it is possible to reduce the amount of the improving material to be used.

When a plurality of injection holes 1a are formed, the reflection plate 10a is provided for each of the injection holes. If, if the injection hole for injecting modifying material toward the stirring blade W ₀ is formed, also provided for the stirring blade W _0. Note that the size of the reflection plate 10a is
Aperture angle of the diameter and the injection hole of, but still depending on the condition of the outer diameter of the stirring blade W _1, is appropriately changed, generally 5-10
A size of about cm is used. Further, the reflection plate 10a is not limited to a flat plate shape, and may be formed into a curved surface shape within a range in which the reflecting improving material does not leak out of the improvement range.

When the ground improvement is performed by the apparatus configured as described above, first, the inner pipe 1 is moved to the rod front side, and the stirring blades W ₀ and W ₁ are closed, and FIG.
As shown in (1), the rod R is inserted into the ground while rotating. When the predetermined ground depth is reached, the rod insertion is stopped, and the inner pipe 1 is slid to the base end side by the inner pipe slide driving means A to open the stirring blades W ₀ and W ₁ . Subsequently, while the improving material is injected from the injection hole 1a of the rod R, the rod R is rotated and stirred upward with the earth and sand, and is pulled upward at a low speed. If an obstacle such as a boulder exists in the stirring ground, for example,
When A, 3B... Collide, the obstacle can be avoided by reducing the diameter of the stirring blades W ₀ , W ₁ by operating the inner tube slide driving means A.

[0021]

As described in detail above, according to the present invention, the apparatus is simple and very inexpensive.
The injected improved material and earth and sand can be uniformly and effectively stirred and mixed without adversely affecting the surrounding ground, and the improved body can be reliably formed within a predetermined range.

[Brief description of the drawings]

FIG. 1 is a diagram showing a wing-spread state of a double tube rod according to the apparatus of the present invention.

FIG. 2 is a closed-wing state diagram of a double pipe rod according to the apparatus of the present invention.

FIG. 3 is a view taken along line III-III in FIG. 1;

FIG. 4 is a diagram showing the state of reflection of an improved material.

FIG. 5 is a detailed structural view of an inner tube slide driving unit.

FIG. 6 is a diagram showing another example of the slide driving means.

FIG. 7 is a view showing still another example of the slide driving means.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Inner pipe, 1a ... Injection hole, 1b ... Drilling bit, 2 ... Outer pipe, 3A * 4A ... 1st non-cutting blade bar-shaped member, 3B * 4B ...
Second continuously cutting edge rod-like member, 10a ... reflector, 20 ... cylinder tube, 11 ... Swivel 12 ... piston tube, 13 ... oil feeding pipe, W ₀ · W ₁ ... stirring blade

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-216710 (JP, A) JP-A-5-321240 (JP, A) JP-A-4-213614 (JP, A) JP-A-5-213614 112925 (JP, A) JP-A-5-118027 (JP, A) JP-A-1-65334 (JP, U) JP-A-55-163341 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) E02D 3/12

Claims (1)

(57) [Claims] 1. A ground improvement rod, one end of which is rotatably connected to a rod tip side and the other end of which is rotatably connected to a connection fitting.
A first non-cutting edge rod member, one end to the connecting fitting rotation was
And a second non-cutting blade bar member freely connected and having the other end pivotally supported on the rod base end side, and at least one or more link-type stirring blades, and the link-type stirring blade for the ground improvement rod. at least one of the both supporting points is movable in the rod axis direction by the slide driving means, the link-type stirring blade is opened,閉翼freely to the rod side by contact and separation of the two support points, and phosphorus
To the rod part within the installation range of
Improved material injection to spray improved material toward a certain link type stirring blade
Forming at least one or more holes;
A reflector for impinging the improver on the tool is provided, and the link type stirring blade is opened and closed.
So that the reflector is parallel to the rod in the state
Soil improvement apparatus having a widening type stirring blade, characterized by being configured to.