JP3370456B2 - Ground improvement equipment - 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 suitable for use in improving soft ground such as sand ground.

[0002]

2. Description of the Related Art As is well known, solidifying materials such as lime and cement are prepared in the form of slurry, and the slurry is stirred and mixed with the soil in the ground to hydrate the solidifying material slurry. Ion exchange between hydration products of clay reaction and clay minerals, or chemical consolidation reaction mainly consisting of pozzolanic reaction etc. is used to chemically solidify the soil and create improved piles in the ground. There is a ground improvement method for improving the ground.

Conventionally, in this ground improvement method, a ground improvement device 1 based on a pile driver as shown in FIG. 5 has been used. In the ground improvement device 1, a stirring rod 4 is rotatably supported by a supporting column 3 provided on the main body 2 around its axis, and the lower end of the stirring rod 4 stirs the soil in the ground G. A schematic structure is provided in which a blade 5, an earth auger 6 for scraping soil in the ground G, and a discharge port 7 for supplying a solidifying material slurry into the ground G from a solidifying material supply means (not shown) are provided. ing.

In order to improve the ground by using the ground improving apparatus 1 as described above, first, the stirring rod 4 is inserted into the ground G while rotating, and the ground auger 6 scratches the ground G to a predetermined depth. move on. Next, the solidified material slurry is supplied to the solidified material slurry by means of the solidified material supply means.
To squirt from. Then, while pulling up the stirring rod 4, the jetted solidified material slurry and the soil of the ground G are stirred by the earth auger 6 and the stirring blades 5 to solidify the soil and form a columnar improved pile in the ground G. Create.

According to the purpose of using the structure built on the ground G or the ground G, such an improved pile is
The ground G was improved by forming it alone or in a block shape, a grid shape, a continuous wall shape, or the like.

[0006]

However, the conventional ground improvement device as described above has the following problems. First, the solidifying material slurry is charged into the ground G in order to create an improved pile by the ground improving device 1. At this time, when the amount of the solidified material slurry becomes equal to or more than the gap ratio of the soil of the ground G, the ground G is lateral May be displaced to. Further, when the ground G has a high density and the large-scale ground improving apparatus 1 is used, the ground G is displaced laterally only by inserting the stirring rod 4 having a large volume into the ground G. Sometimes. When the ground G is displaced laterally in this way,
There is a problem that the peripheral part of the area to be improved is affected.

In order to solve such a problem, there is a ground improvement device 1'as shown in FIG. The ground improvement device 1 ′ has a configuration in which spiral blades 8 are spirally formed on the outer peripheral surface of the stirring rod 4. In the ground improvement device 1 ', the spiral blade 8 that rotates integrally with the stirring rod 4 discharges the earth and sand stirred by the stirring blade 5 to the ground, thereby preventing the lateral displacement of the ground G. ing.

However, in such a soil improvement apparatus 1 ', since the stirring blade 5 and the spiral blade 8 are provided coaxially, they rotate integrally at the same speed. Therefore, if the rotation speed of the stirring blade 5, that is, the rotation speed of the stirring rod 4 is set so that the required improved quality of the ground G can be obtained, the lateral displacement of the ground G is reduced in the spiral blade 8 rotating at this speed. It may not be possible to discharge the amount of earth and sand necessary to prevent this. On the contrary, if the rotation speed of the spiral blades 8, that is, the stirring rod 4 is set so that the required amount of discharged soil is obtained, it goes without saying that the improvement quality of the ground G is affected.

Further, when the stirring rod 4 is operated at a rotation speed corresponding to the improved quality of the ground G, in order to secure the required amount of soil removal by the spiral blade 8 rotating at this rotation speed, the blade diameter and Although it may be possible to replace the spiral blade 8 with another one having a different pitch or the like, replacing the spiral blade 8 requires a great deal of time and cost and is not realistic.

In this way, it is difficult for construction management to satisfy both purposes of improving quality of the ground G and preventing lateral displacement. The present invention has been made in consideration of the above points, and provides a ground improvement device capable of performing soil removal commensurate with geology and improving the ground without causing lateral displacement. With the goal.

[0011]

A ground improvement device according to a first aspect of the present invention is provided with a solidifying material supply mechanism for supplying a solidifying material to the soil in the ground, and a stirring blade for agitating the ground at the tip. A stirring rod and a spiral rod having spiral blades formed in a spiral shape along the outer peripheral surface and extending in parallel with the stirring rod are provided so as to be movable in the axial direction thereof, respectively. the rod is configured to drive source for rotationally driving the respective about the axis is provided independently for each of the stirring rod
An outer cylinder is provided at the lower end of the
Is a constant that extends in the vertical direction formed on its peripheral surface.
A long guide hole is formed on the outer peripheral surface of the stirring rod.
By engaging the protruding parts that are
Stretchable to the stirring rod in the enclosure and integrated around the axis
The stirring blade is provided on the outer cylinder.
And the lower end of the stirring rod is below the outer cylinder.
A leading bit that can project below the edge is provided
It is characterized in that the portion is provided with a solidified material discharge port .

A ground improvement device according to a second aspect is the first aspect.
The ground improvement device described above is characterized in that the drive source is provided with an adjusting mechanism for adjusting the rotational speed of the spiral rod.

[0013]

According to the first aspect of the present invention, the ground improvement device is provided with the solidifying material supply mechanism for supplying the solidifying material to the soil in the ground, the stirring rod having the stirring blades, and the spirally formed spiral. Spiral rods provided with blades are provided in parallel with each other, each is movable in its axial direction, and a driving source for rotationally driving each of them is provided separately for the stirring rod and the spiral rod. . As a result, the stirring rod is rotated to penetrate into the ground, and the solidifying material supplied into the ground by the solidifying material supply mechanism is stirred and mixed with the earth and sand in the ground by stirring blades to solidify and improve the ground. can do.
Further, by rotating the spiral rod, the earth and sand in the ground can be discharged. Moreover, since the agitating rod and the spiral rod are provided with drive sources independently of each other, they can be operated under different optimum conditions.

According to a second aspect of the invention, the drive source is provided with an adjusting mechanism for adjusting the rotational speed of the spiral rod. By changing the rotation speed of the spiral rod in this way, the amount of earth and sand discharged can be adjusted arbitrarily.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. As shown in FIG. 1, the ground improvement device 10
A support column 12 was hung vertically in front of a main body 11 having an endless caterpillar 11a for moving, and a solidifying material supply pump (solidifying material supply mechanism: not shown) for supplying a solidifying material to the ground G was provided. It is composed.

The support column 12 is provided with a drilling / agitation mechanism 13 for drilling and stirring the ground G, and an earth discharging mechanism 14 for discharging earth and sand from the ground G.

As shown in FIG. 2, the drilling / agitation mechanism 13
Is provided with two stirring rods 15, 15. The stirring rods 15 and 15 have their upper ends connected to and supported by the rotary shaft of a drive motor (driving source) 16 provided on a support column 12 (see FIG. 1) so as to be vertically movable. Each stirring rod 1 by the drive motor 16
5 is driven to rotate about the axis. The intermediate portions of the stirring rods 15 and 15 are rotatably supported around their axes by an interference band 17 that is vertically movable along the column 12.

As shown in FIG. 3, the lower end of each stirring rod 15 is provided with an outer cylinder 15a having an inner diameter larger than the outer diameter of the stirring rod 15. A guide hole 18 of a constant length extending in the vertical direction is formed on the peripheral surface of the outer cylinder 15a. On the other hand, a convex portion 19 that engages with the guide hole 18 is formed on the outer peripheral surface of the lower end portion of the stirring rod 15. As a result, as shown in FIGS. 3A and 3B, the stirring rod 15 and the outer cylinder 15a are configured to be expandable and contractable by a stroke corresponding to the length of the guide hole 18. In the following description, as shown in FIG. 3A, the protrusion 19 is located at the lower end of the guide hole 18,
As shown in FIG. 2, a state in which the stirring rod 15 and the outer cylinder 15a are most contracted is referred to as a "fully bent state". Also, FIG.
As shown in (b), the convex portion 19 is located at the upper end of the guide hole 18, and as shown in FIG. ". Further, by engaging the guide hole 18 and the convex portion 19, the stirring rod 15 and the outer cylinder 15a are configured to integrally rotate about their axes.

The outer cylinder 15a is provided with a first stirring blade (stirring blade) 20 at the upper end and a second stirring blade (stirring blade) 21 at the lower end. These first stirring blades 20
The second stirring blade 21 and the second stirring blade 21 are provided so as to be orthogonal to each other in a plan view. Further, at the tip of the second stirring blade 21, there are provided bits 22, 22, ... For efficiently stirring the ground G.

On the other hand, as shown in FIG. 3 (a), leading bits 23, 23 for efficiently agitating the ground G are provided on the lower end surface of each stirring rod 15. These leading bits 23, when the outer cylinder 15a is fully bent, the lower end surface of the outer cylinder 15a and the bits 22, 22, ...
It is designed to project downward.

A discharge port 24 is formed in the convex portion 19 of the stirring rod 15. One end of a slurry hose (not shown) that passes through the stirring rod 15 is connected to the discharge port 24. The other end of the slurry hose is connected to a solidifying material supply pump (not shown) provided in the main body 11 (see FIG. 1) for feeding the solidifying material. Then, the solidified material slurry supplied from the solidified material supply pump through a slurry hose (not shown) is
It is configured to be ejected from the discharge port 24.

As shown in FIG. 2, the soil discharging mechanism 14
Is provided with a spiral rod 26 disposed in parallel between the stirring rods 15 and 15.
On the outer peripheral surface of the spiral rod 26, spiral blades 27 having a constant outer diameter and continuous in a spiral shape are formed. Further, at the lower end of the spiral rod 26, an excavation head 28 having bits 28a, 28a, ... Is provided. When the spiral rod 26 rotates in the direction indicated by reference numeral (a) in FIG. 2, the spiral wing 27 is embedded in the ground G, and when it rotates in the direction indicated by reference numeral (b) in FIG. The spiral wing 27 sends out the earth and sand in the ground G upward.

The upper end of the spiral rod 26 is
The drive motor (drive source) 29 provided integrally with the drive motor 16 is connected to and supported by the rotary shaft, and is driven to rotate about the axis by the drive motor 29. The drive motor 29 is provided integrally with the drive motor 16 for rotating the stirring rod 15. As a result, the spiral rod 26
The stirring rods 15, 15 supported by the drive motor 16 are integrated with each other so as to be vertically movable along the support columns 12 (see FIG. 1).

The drive motor 29 for rotationally driving the spiral rod 26 and the drive motor 16 for rotationally driving the stirring rods 15 and 15 are integrally provided, but each has an independent control mechanism. Has been done. As a result, the spiral rod 26 and the stirring rods 15 and 15 can be independently operated at independent rotation speeds. Then, the drive motor 29
Is an inverter controlled, spiral rod 2
The rotation speed of No. 6 is provided with an adjusting mechanism that can be arbitrarily set within a range of 15 to 35 rpm, for example.

As shown in FIG. 1, a pull-out winch 31 is provided behind the main body 11. One end of a wire 32 is fixed to the pull-out winch 31.
The other end of the wire 32 is a sheave 3 rotatably supported by a support member 34 provided at the upper end of the support column 12.
5, 36, and a sheave 37 that is rotatably supported on the upper surface of the drive motor 16, and is fixed to the lower surface of the support member 34. As a result, when the wire 32 is taken up by the pull-out winch 31, the drive motor 16, that is, the stirring rods 15 and 15 and the spiral rod 26 (see FIG. 2) are moved up along the support column 12.

Next, the ground improvement method using the ground improvement device 10 having the above-mentioned structure will be described in detail. First, the ground G
The stirring rods 15 and 15 are positioned at predetermined positions. Next, the drive motor 16 rotationally drives the stirring rods 15 and 15 to rotate the first stirring blades 20 and 20 and the second stirring blades 21 and 21. Then, the pull-out winch 31 is operated to feed the wire 32. Then, the first stirring blades 20 and 20 penetrate into the ground G while rotating due to the own weight of the hole drilling / agitation mechanism 13 and the earth discharging mechanism 14, whereby the ground G is drilled to a predetermined depth. At this time, as shown in FIGS. 2 and 3A, the first stirring blades 20, 20 and the second stirring blades 21,
The outer cylinder 15a to which 21 is attached is in a fully bent state by the reaction force from the ground G, and the ground G is also drilled by the preceding bit 23 provided at the tip of the stirring rod 15. Has become. Note that the solidifying material slurry is not discharged during this drilling. At the time of drilling, the drive motor 29 rotates the spiral rod 26 in the direction indicated by reference numeral (a) in FIG. 2 to cause the spiral wing 27 to bite into the ground G, so that the spiral rod 26 is moved to the ground G. Let's penetrate inside.

After the first stirring blades 20 and 20 have finished drilling to a predetermined depth, the drawing winch 31 stops the feeding of the wire 32, and the stirring rods 15 and 15 are stopped.
And the descent of the spiral rod 26 is stopped. Then, the rotation direction of the drive motor 16 is switched and the stirring rods 15 and 15 are reversed. And the stirring rods 15, 1
The solidified material supply pump is operated for a certain period of time while 5 is being rotated, and the solidified material slurry is ejected from the discharge ports 24, 24 into the ground G to perform the tip treatment of the improved pile.

Next, the rotation direction of the drive motor 29 is switched, and the spiral rod 26 is rotated in the reverse direction (direction shown by reference numeral (b) in FIG. 4). Spiral rod 26 at this time
The rotation speed is set such that the amount of soil discharged by the rotation of the spiral rod 26 is an amount commensurate with the amount of the solidified material slurry discharged from the discharge ports 24, 24 of the stirring rods 15, 15.

Then, the stirring rods 15 and 15 and the spiral rod 26 are rotated while ejecting the solidifying material slurry, and at the same time, a wire 32 is drawn by a pulling winch 31.
And the stirring rods 15 and 15 and the spiral rod 26 are pulled up. At this time, as shown in FIG. 3 (b) and FIG. 4, the outer cylinder 15 a of each stirring rod 15
Is in a fully extended state, the leading bit 23 provided at the tip of the stirring rod 15 is housed in the outer cylinder 15a, and the discharge port 24 is positioned at the base of the first stirring blade 20.

Discharge ports 24, 24 of the stirring rods 15, 15.
The solidifying material slurry discharged from the first stirring blades 20, 2
0 and the second stirring blades 21 and 21 mix and mix with the soil of the ground G. Then, the hydration reaction of the solidifying material slurry mixed with the earth and sand, the ion exchange action between the hydration product of this hydration reaction and the clay mineral, or the chemical consolidation reaction mainly consisting of the pozzolanic reaction etc. It is chemically solidified, whereby a columnar improved pile is formed in the ground G. At the same time, the rotation of the spiral rod 26 causes the earth and sand in the ground G to be discharged to the ground. At this time, as described above, since the rotation speed of the spiral rod 26 is set so as to be the discharged amount corresponding to the discharge amount of the solidifying material slurry, the volume of the ground G does not change.

After that, the above steps are repeated to construct a predetermined number of improved piles at predetermined positions to complete the improvement of the ground G.

As described above, the ground improvement device 10 includes the stirring rod 1 having the first stirring blade 20 and the second stirring blade 21.
5, 15 and a spiral rod 26 having a spiral wing 27 are provided parallel to each other and movable in their respective axial directions, and further provided with a solidifying material supply mechanism for supplying the solidifying material slurry into the ground G. It is designed as a fixed structure. As a result, the drive motor 16 causes the stirring rods 15, 1
5 is rotated to drill the ground G, and the discharge ports 24, 2
The ground G can be improved by stirring and mixing the solidifying material slurry supplied from 4 into the ground G with the first stirring blade 20 and the second stirring blade 21 with the earth and sand in the ground G. Then, as the solidifying material slurry is discharged, the spiral rod 26 is rotated by the drive motor 29, so that the ground G
Since the earth and sand inside can be discharged, the lateral displacement of the ground G can be prevented. At this time, stirring rod 1
Since the drive motor 16 that drives the motors 5 and 15 and the drive motor 29 that drives the spiral rod 26 are controlled independently of each other, they can be operated under optimum conditions. As a result, the stirring rods 15 and 15 can be operated at the rotational speed for obtaining the required improved quality of the ground G, and the spiral rod 26 corresponds to the geology of the ground G and the injection amount of the solidifying material slurry. It can be operated at a rotational speed to get the amount of soil dumped. As a result, the contradictory objectives of the improved quality of the ground G and the prevention of lateral displacement can be satisfied without making the construction management particularly difficult.

Further, the drive motor 29 for driving the spiral rod 26 is constructed so that the rotational speed of the spiral rod 26 can be arbitrarily adjusted by an inverter-controlled adjusting mechanism. Accordingly, by adjusting the rotation speed of the spiral rod 26 according to the geology of the ground G to be improved, the injection amount of the solidifying material, and the like, it is possible to always ensure the optimum amount of earth removal, and the lateral side of the ground G. Not only the displacement but also the overflow of the injected solidifying material slurry can be prevented. Further, even when the injection amount of the solidifying material slurry is changed in response to the change in the geology of the ground G during the construction of the improved pile, the rotation speed of the spiral rod 26 is changed accordingly, and the amount of discharged soil is changed. Can be changed.

In the above embodiment, the ground improvement device 10 is a triaxial type equipped with two stirring rods 15 and one spiral rod 26, but of course the invention is not limited to this. In addition to the biaxial type including one rod 15 and one spiral rod 26, a stirring rod 15,
A multi-axis type having a plurality of spiral rods 26 may be used. Further, by constructing the improved piles adjacent to each other in one direction by the soil improvement device 10, it is possible to construct an underground continuous wall.

[0035]

As described above, according to the ground improvement device of the first aspect, the ground improvement device is provided with the solidifying material supply mechanism for supplying the solidifying material into the ground, and the stirring with the stirring blade. The rod and the spiral rod having spiral spiral blades are arranged parallel to each other , and the stirring rod is provided at the lower end of the stirring rod.
It is equipped with a tube that can be expanded and contracted and rotated integrally,
A leading bit is provided at the end to engage with the guide hole of the outer cylinder
The convex portion is provided with a solidified material discharge port. This allows the stirring rod to rotate and penetrate into the ground,
The ground can be improved by agitating and mixing the solidified material supplied into the ground by the solidified material supply mechanism with the earth and sand in the ground by a stirring blade. At this time, by supplying the solidifying material into the ground and rotating the spiral rod,
Since soil in the ground can be discharged, lateral displacement of the ground can be prevented. Moreover, with a stirring rod,
The spiral rod and the driving source are independently provided. Thereby, the optimum conditions for the stirring rod and the spiral rod, namely, in the stirring rod, the rotation speed for obtaining the required improved quality of the ground,
The spiral rod can be operated at the geology of the ground and the rotation speed for obtaining the amount of soil discharged corresponding to the amount of solidified material injected. Therefore, the contradictory purposes of the ground improvement quality and the prevention of lateral displacement can be satisfied without making the construction management particularly difficult.

According to the ground improvement device of the second aspect, the drive source is provided with the adjusting mechanism for adjusting the rotational speed of the spiral rod. As a result, if the rotation speed of the spiral rod is adjusted according to the geology of the ground to be improved, the injection amount of the solidifying material, etc., the amount of earth and sand discharged can be arbitrarily changed. In addition to the lateral displacement, it is possible to prevent the injected solidified material from overflowing. Further, even when the geology of the ground changes during the construction of the improved pile, the rotation speed of the spiral rod is changed accordingly, so that the optimum amount of soil removal can always be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a geological improvement device according to the present invention, and is a side view showing an outline of the device.

FIG. 2 is a view showing a stirring rod and a spiral rod of the apparatus, and is a front view showing a state where the stirring rod is fully bent.

FIG. 3 is a front view showing the tips of the stirring rod and the spiral rod.

FIG. 4 is a front view showing a state where the stirring rod is fully extended.

FIG. 5 is a side view showing an example of a conventional ground improvement device.

FIG. 6 is a side view showing another example of the conventional ground improvement device.

[Explanation of symbols]

10 Ground Improvement Device 15 Stirring Rod 15a Outer Cylinders 16 and 29 Drive Motor (Drive Source) 18 Guide Hole 19 Projection 20 First Stirring Blade (Stirring Blade) 21 Second Stirring Blade (Stirring Blade) 23 Preceding Bit 24 Discharge Port 26 Spiral Rod 27 Spiral Wing G Ground

─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Junji Tanaka 1-13-23, Kashiidai, Higashi-ku, Fukuoka-shi, Fukuoka (72) Inventor Sumio Ito 4-76 Matsugaoka, Kasuga-shi, Fukuoka Reference (56) 6-158641 (JP, A) JP-A-6-158642 (JP, A) JP-A-7-292653 (JP, A) JP-A-62-68917 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E02D 3/12 102

Claims (2)

(57) [Claims] 1. A stirrer rod having a stirrer blade for stirring the ground at a tip end, and a stirrer rod having a stirrer blade for stirring the ground, and a spiral rod formed along the outer peripheral surface. And a spiral rod that includes a spiral blade and extends in parallel with the stirring rod, is provided so as to be movable in the axial direction thereof, and the stirring rod and the spiral rod each have a drive source for rotationally driving them around the axis. Is independently provided, and the agitation is performed.
An outer cylinder is provided at the lower end of the rod, and
The outer cylinder extends in the vertical direction formed on the peripheral surface of the outer cylinder.
A guide hole of constant length is formed on the outer peripheral surface of the stirring rod.
The length of the guide hole can be
Within the range of
It is possible to rotate integrally, and the stirring blade is provided on the outer cylinder.
And the outer cylinder is attached to the lower end of the stirring rod.
A leading bit that can project below the lower end of
The ground improvement device, wherein the convex portion is provided with a solidified material discharge port . 2. The ground improvement device according to claim 1,
The ground improvement device, wherein the drive source is provided with an adjusting mechanism for adjusting the rotation speed of the spiral rod.