JP2003138556A - Soil improvement method and device using powder improvement material and powder pneumatic feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely change over the injection of a solidification material despite of having a simple structure and mechanism. SOLUTION: In an insertion process of an improvement rod 1, if a lower part injection port 1b arrives from the lowermost end in a depth-directional improvement range to an upper position by a separate distance between a lower part injection port 1b and an upper part injection port 1u, the other opening of a changeover pipe 2P of a changeover device 2 is connected to a first outlet 2a alone and the improvement rod 1 is rotationally inserted while injecting compressed air with the powder solidification material from a solidification material pneumatic feeding device 3 from the lower part injection port 1u alone. In a pull-up process of the improvement rod, the other opening of the changeover pipe 2P is changed over to a state connected to a second outlet 2b alone, and the improvement rod 1 is rotationally pulled up while injecting the compressed air with the powder solidification material from the solidification material pneumatic feeding device 3 from the upper part injection port 1u alone.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement method using a solidifying material for powder and granules, an apparatus therefor, and a powdery granule pressure-feeding and feeding device which can be suitably used for continuously and quantitatively supplying powdery granules on a pressurized air.

[0002]

2. Description of the Related Art As a construction method for improving the ground, an improved rod having stirring blades is inserted into the ground while rotating, and during the insertion process and the pulling process, a powdery granular material is formed from a predetermined portion of the improved rod. It is known to inject a solidifying material (hereinafter, also simply referred to as a solidifying material) to form a columnar solidification-treated body in the ground to treat soft ground.

For example, a method known as a deep layer mixing processing method corresponds to this.

Generally, in the deep-layer mixing method, in consideration of variations in ground strength, a method is adopted in which, instead of injecting the solidifying material at the time of the penetration of the agitating blade, pulling injection is performed in a state of being loosened once by the penetration. There is. Therefore,
As shown in FIG. 0, the main injection hole 1U has the stirring blade groups 1w, 1
It is common to use the improved rod 1 attached to the uppermost part of w ... In this case, a so-called unimproved portion A3 in which the solidifying material is not mixed only by stirring is formed between the uppermost blade 1w and the lowermost blade 1w. Countermeasures for eliminating the unmodified portion A3 on the tip side have been one of the problems in the deep layer mixing processing method, and various countermeasures as described below have been taken so far.

(Prior Art 1) In the prior art 1, a dedicated solidifying material injection pipe is attached to the outside of the improved rod and the injection position of the solidifying material is switched by sliding this pipe up and down to switch between the uppermost blade and the uppermost blade. The improved material is created by injecting the solidifying material also to the portion between the lower blades.

(Prior Art 2) In the prior art 2, an injection hole is provided in the vicinity of the stirring blade in the range between the uppermost blade and the lowermost blade, and the stirring blade portion can be swung several tens of degrees. The injection holes are opened and closed by the stirring blades in the swinging range, and the opening and closing of the injection holes are switched according to the rotating direction of the blades by utilizing the resistance force applied to the blades.

(Prior Art 3) In the prior art 3, a solidifying material supply pipe is arranged in the improved rod pipe to form a double pipe structure, and the injection is performed also in a range between the uppermost blade and the lowermost blade of the improved rod. A hole is drilled and a cylinder is provided at the top of the rod.By sliding the solidifying material supply pipe, which is the inner pipe, up and down by this cylinder, and switching the injection hole communicating with this, the space between the uppermost blade and the lowermost blade is changed. A solidified material is also sprayed onto the site to create an improved body.

On the other hand, in the ground improvement using such a powdery / solidified material, a device for sending the powdery / solidified material on compressed air (pressurized gas, for example, compressed air) is used. Examples of such a pressure-feeding / supplying device include JP-A-8-113370, JP-A-8-113369, and JP-A-10-5.
Some are disclosed in Japanese Patent Publication No. 9542.

[0009]

However, first of all, regarding the ground improvement method, Prior Art 1 was applied to a marine construction machine having two or more agitating blades, and the application to land is structurally operated. Very sexually difficult. Further, the prior art 2 expects the switching to the last, and there is no method for confirming whether the switching is performed, and there is a problem that the blades may not move and the switching may not be performed due to the adhesion of the solidifying material. . Further, in the prior art 3, although it can be confirmed whether or not the switching is performed by the stroke of the cylinder, there is a problem in that the structure becomes very complicated.

On the other hand, in the powder and granular material pressure supply device, the powder and granular material and the compressed air are sent in separate systems while the powder and granular material are placed on the compressed air and delivered, so that the compressed air leaks to the supply side of the granular material. It is necessary to prevent the backflow of powder and granules. In addition, considering the application to the above-mentioned ground improvement bulletin, it is easy to carry it to the site, requires only a small installation area, is easy to operate and maintain, and can supply a large amount of fixed quantity. Required.

However, the conventional powder / granule pressure-feeding / feeding device has only adopted a complicated structure in order to prevent backflow of the powder / granular substance due to compressed air. As a result, there are problems that maintenance such as cleaning of the inside is complicated and that the device is too large to carry in and install. Furthermore, it was difficult to control the amount of powder used.

[0012] Therefore, a main object of the present invention is to provide a ground improvement method and an apparatus which have a simple structure / mechanism but can reliably switch the injection of the solidifying material. Another problem is that it is possible to reliably prevent backflow of powder and granules due to compressed air, and it has a simple structure and mechanism, which makes it extremely easy to perform maintenance such as cleaning the inside, and it is possible to compactly pump a large volume. Another object of the present invention is to provide a powder and granular material pressure-feeding device capable of easily and accurately managing the amount of powder or granular material used.

[0013]

The present invention which has solved the above-mentioned problems is as follows. <Invention of Claim 1> A lower injection hole provided at a lower end portion, an upper injection hole provided above the lower injection hole, and a stirring blade provided in a range extending from the lower injection port to the upper injection port, A casing having an improved rod, a supply port into which compressed air accompanied by a solidifying material is blown, a first outlet port connected to the lower injection port, and a second outlet port connected to the upper injection port. And one opening is connected to the supply port in the casing, and the other opening is movable to each of a connection position with the first outlet and a connection position with the second outlet. Provided with a switching pipe line and a pressure holding means for keeping the pressure in the casing at a predetermined level or higher, and a switching device, and compressed air accompanied by the powdery solidified material to the improved rod via the switching supply device. Supply by pressure Using the soil modifying apparatus, comprising: a location, an; while rotating the improved rod to its axis around
After inserting until the lower injection port reaches the lower end of the depth direction improvement range in the improvement target ground, at least the upper injection port is pulled up to reach the upper end of the depth direction improvement range, and in the insertion process of the improved rod. If the lower injection port reaches a position above the lowermost end of the depth direction improvement range by the distance between the lower injection port and the upper injection port, thereafter, the other of the switching pipelines The opening is connected only to the first delivery port, while the compressed air accompanied by the powdery solidification material from the solidification material pumping device is injected from only the lower injection port, the improved rod is rotationally inserted,
In the process of pulling up the improved rod, the other opening of the switching pipe is switched to a state in which it is connected only to the second outlet, and the compressed air from the solidifying material pressure-feeding device together with the powdery solidifying material is transferred to the upper part. A ground improvement method using a powdery or granular material improving material, wherein the improved rod is rotated and pulled up while being injected only from an injection port.

(Effects) In the present invention, the switching between the supply of the solidified material to the upper injection port and the supply of the solidified material to the lower injection port is performed by the switching device interposed in the solidification material supply path from the pressure feeding supply device to the improved rod. To do. Therefore, the structure of the improved rod is very simple.

Further, the switching device of the present invention is provided with respect to the supply port into which compressed air accompanied by the solidifying material is blown, the first delivery port connected to the lower injection port of the improvement rod, and the upper injection port of the improvement rod. In the casing having the second outlet connected thereto, one opening is connected to the supply port, and the other opening is connected to the first outlet and the second outlet. Each has a switching conduit that is movable, and the other opening of the switching conduit is moved to a connection position with the first delivery port or a connection position with the second delivery port. The transmission route is switched. Therefore, the structure / mechanism is very simple, and very reliable switching is possible.

During this switching, when the switching conduit is in communication with one of the outlets, the other outlet is in communication with the casing. Therefore, there is a possibility that the powder or granular material may flow back from the other outlet, or ground water or soft soil may flow back from the corresponding injection port, but in the present invention, the pressure holding means for keeping the pressure in the casing at a predetermined level or higher. It is possible to prevent such a backflow because of the above.

On the other hand, in the invention described in claim 1, by utilizing such switching, in the process of inserting the improved rod,
When the lower injection port reaches a position above the lowermost end of the depth direction improvement range by the distance between the lower injection port and the upper injection port, thereafter, the other opening of the switching pipeline is opened to the first opening. The improved rod is rotationally inserted while being connected only to the delivery port and injecting the compressed air accompanied with the powdery solidified material from the solidification material pumping device only from the lower injection port. Therefore, the unimproved portion on the tip side as described above can be eliminated.

<Invention of Claim 2> A lower injection hole provided at a lower end portion, an upper injection hole provided above the lower injection hole, and an agitation provided in a range extending from the lower injection port to the upper injection port. An improved rod having a wing, which is connected to each of the lower injection port and the upper injection port, supplies the powdery solidification material to the lower injection port, and supplies the powdery solidification material to the upper injection port. A ground improvement device comprising: a switching device for switching; and a pressure feeding and supplying device for supplying compressed air accompanied by a solidified material for granules to the improved rod via the switching and supplying device, wherein the switching device is; A supply port into which compressed air accompanied by the solidified material from the solidified material pressure-feeding device is blown, a first outlet connected to the lower injection port, and a second outlet connected to the upper injection port. Be prepared And one opening connected to the supply port in the casing, and the other opening at each of the connection position with the first delivery port and the connection position with the second delivery port. A movable switching pipe, drive means for giving a moving force to the switching pipe, and pressure holding means for keeping the pressure in the casing at a pressure equal to or higher than the pressure of the solidifying material from the solidifying material pumping device. A ground improvement device using a powder and particle solidifying material, characterized in that

(Operation and effect) The same operation and effect as the invention according to claim 1 can be obtained.

<Invention of Claim 3> The improved rod is provided with a pair of side-by-side transfer pipelines which are respectively connected to the lower injection port and the upper injection port and extend to the upper end along the rod longitudinal direction. And these transport lines
It is connected to the first outlet and the second outlet of the switching device via a swivel device, respectively, and the swivel device is connected to the upper fixing portion and its lower surface in an airtight and rotatable manner. Has a lower rotating part, and the upper fixed part of the swivel device has a pair of conduits, and the pair of conduits are respectively connected to the first outlet and the second outlet of the switching device. While having the connected side-by-side arrangement side portions, one of the conduits gradually approaches the rotation center line of the lower rotation portion as it goes toward the connection surface side with the lower rotation portion, and at the connection surface with the rotation center line. It has a coaxial circular outlet, and the other conduit gradually deforms so as to surround the one conduit as it goes toward the connection surface side with the lower rotating part, and the circular shape of the one conduit at the connection surface. Take the exit coaxially The swivel device has a surrounding annular outlet, while the lower rotating part of the swivel device has a pair of conduits, which are side by side connected to a pair of conveying conduits of the improved rod, respectively. In addition to having the exit side portion of the arrangement, one of the conduits has a circular inlet that gradually approaches the rotation center line toward the connection surface side with the upper fixed portion and is coaxial with the rotation center line at the connection surface. Then
The other pipe is gradually deformed so as to surround the one pipe as it goes toward the connection surface side with the upper fixed portion, and the annular inlet coaxially surrounds the circular inlet of the one pipe at the connection surface. The circular outlet and the circular inlet, and the annular outlet and the circular inlet, which are on the connecting surface between the fixed portion and the rotating portion, are configured to be symmetrical with respect to the connecting surface and always communicate with each other. The ground improvement device using the powdery or granular material solidifying material according to claim 2.

(Effects) When the switching device is used to switch the injection of the solidified material from the upper and lower injection ports as in the present invention, the improved material is provided with the solidified material conveying pipelines for the upper and lower injection ports. It is desirable to provide them individually. In this case, if a pair of transfer pipelines are arranged side by side in the improved rod, the structure will be very simple, and the transport resistance and cross-sectional shape of both pipelines will be equal, and the solidified material will be injected from the upper and lower injection ports in a well-balanced manner. It is preferable because it is possible.

However, if the transfer pipes are arranged side by side, they also rotate with the rotation of the improved rod, and the transfer pipe and the solidified material pressure feeding / supplying device cannot be connected. For this reason, the conventional improved rod has a double pipe structure in which one of the inner pipe and the outer pipe is connected to the upper injection port and the other is connected to the lower injection port. Although it is connected by a swivel device, the structure of the improved rod becomes complicated, and the transfer resistance and cross-sectional shape of the inner pipe and outer pipe are different, and the solidified material injection at the upper injection port and that at the lower injection port are different. Difficult to balance.

On the other hand, in the present invention, among the solidified material conveying paths from the switching device to the upper and lower injection ports of the improved rod,
Since only the connecting surface portion of the swivel device has a double pipe structure, and the inlet side portion and the outlet side portion of the swivel device are arranged side by side, the transfer pipelines in the improved rod can be arranged side by side. In addition, since the pair of pipes in the swivel device gradually change to a double pipe shape as they approach the connecting surface, there is also an advantage that the solidifying material can smoothly pass without adhering and accumulating.

<Invention of Claim 4> A storage chamber having a powdery / granular material supply port in the upper part and a discharge port in the lower end, and an externally provided powdery / granular material supply port provided in the storage chamber. A measuring container configured to receive and store the granular material and discharge the stored granular material into the storage chamber, and a measuring means for measuring the amount of the granular material in the measuring container, An intermediate chamber which is connected to the powder and granular material supply means through the first opening / closing valve to the lower end discharge port of the storage chamber and has a discharge port at the lower end, and a lower end discharge of the intermediate chamber. A pressure feeding chamber connected to the outlet via a second opening / closing valve, and a predetermined amount of powder particles stored in the pressure feeding chamber are continuously taken out,
And a low level detecting means for detecting a low level state in which the amount of powder or granular material stored in the pressure feeding chamber does not reach a predetermined low level. During the granule supply operation, the delivery means is constantly operated to continuously deliver a fixed amount to the outside, while the first open / close valve is closed when the low level state is detected by the low level detection means. In this state, the second on-off valve is opened to perform a pressure-feeding chamber replenishing operation for supplying the granular material in the intermediate chamber to the pressure-feeding chamber, and then the first on-off valve with the second on-off valve closed. When the on-off valve is opened and the granular material stored in the measuring container is discharged to the intermediate chamber to supply the intermediate chamber, and at least the first on-off valve is closed, And configured to perform a weighing container supply operation for receiving a predetermined amount of powdery grains into the metering vessel from that granular material pumping supply apparatus according to claim.

<Operation and Effect> The invention according to claim 4 relates to a powder and granular material pressure-feeding device which can be preferably used in the inventions according to claims 1 to 3. In the present apparatus, when the low level state is detected by the low level detecting means, the second open / close valve is opened with the first open / close valve closed to move the powder / granular material in the intermediate chamber to the pressure feeding chamber. The pressure feeding chamber replenishing operation for supplying to the
With the on-off valve closed, the first on-off valve is opened, the powder and granular material stored in the measuring container is discharged and supplied to the intermediate chamber, and at least the first on-off valve is closed. Then, the measuring container supply operation for receiving a predetermined amount of powdery particles from the outside into the measuring container is performed. Therefore, although pressured air is mixed in the pressure-feeding chamber, at least one of the first and second opening / closing valves is always closed. Therefore, while effectively preventing backflow of the granular material due to pressured air, the measuring container, the intermediate chamber, and the An appropriate amount of powder or granules can be stored in the pressure feeding chamber at all times, and the powder or granules can be continuously delivered to the outside by the rotary feeder.

Further, in order to prevent such backflow, the present invention has a very simple structure because the solidifying material supply path is shut off only at intervals by the two opening / closing valves, so that maintenance such as internal cleaning is also performed. It's very easy. Further, since the measuring container and the intermediate chamber need only store the powder and granules sufficient for supplying the powder and granules to the pressure feeding chamber, the device can be downsized.

On the other hand, when the on-off valve is used, although the powder and granules are supplied to the pressure feeding chamber in a batch system, the rotary feeder finally sends the powder and granules to the outside. it can.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. <Regarding Ground Improvement Method and Apparatus Thereof> FIG. 1 shows an outline of an example of the ground improvement apparatus according to the present invention. The improvement rod 1, the swivel device 4, and the switching device 2 inserted into the ground.
And a pressure-feeding and feeding device 3 for the solidified powder material. The improved rod 1 has a lower injection hole 1b provided at a lower end portion thereof, an upper injection port 1u provided above the lower injection hole 1b at a predetermined distance, and an appropriate interval in a range from the lower injection port 1b to the upper injection port 1u. And a plurality of stirring blades 1w, 1w ... Further, the excavating bit 1a having an appropriate shape is provided at the lower end of the stirring blade 1w and the tip of the shaft.
1c are provided respectively.

As shown in FIG. 2, the switching device 2 has a casing 2C. As the casing 2C, one that can be completely sealed in a use state so that the pressure of the present invention can be held is used. Further, the casing 2C is provided with a supply port 2i which is connected to the outlet side of the solidified material pressure feeding / supplying device 3 through a pipe P1 at the center of the upper portion of the side wall on one side, and both side portions of the lower side wall of the other side. In addition, for the lower injection port 1b and the upper injection port 1u of the improved rod 1, the conduit P
First outlet port 2a connected one-to-one via 2 and P3
And the second outlet port 2b are arranged in parallel, one opening is connected to the supply port 2i, and the other opening is connected to the first outlet port 2a (that is, a communicating position). The same shall apply hereinafter) and a switching pipe line 2P that is movable is provided at each of the connection positions with the second delivery port 2b.

Particularly in this example, the movement of the switching conduit 2P is as shown in FIG.
As shown in FIG. 5, the cylinder 2S mounted outside the case 2C is reciprocally driven. That is, one opening of the switching pipeline 2P is coaxially and rotatably connected to the supply port 2i, and the switching pipeline 2P by this rotation is connected.
The switching conduit 2P is bent so that the locus of the opening on the other side of P passes through the first outlet 2a and the second outlet 2b, and the reciprocating driving force from the cylinder 2S mounted outside the case 2C is It is mechanically converted into a rotational force in the rotation direction of the switching pipe 2P and transmitted to the switching pipe 2P. Thus, the switching movement of the switching pipe 2P described above is possible.

Further, as pressure holding means for keeping the pressure in the casing 2C at a predetermined level or higher, an inlet 2n for introducing compressed air such as compressed air is formed at an appropriate position of the casing 2C, and the compressed air introducing port 2n is connected to the inlet 2n. A compressed air supply device such as a compressor (not shown) is connected. As this compressor, a compressor common to the solidified material pressure feeding and supplying device can be used.

On the other hand, a more preferred detailed construction of the improved rod 1 and swivel device 4 is shown in FIGS. That is, as shown in FIG. 3, the improved rod 1 includes a pair of transfer pipelines 1p and 1p, which are respectively connected to the lower injection port 1b and the upper injection port 1u and extend to the upper end along the rod longitudinal direction. The transfer conduits 1p, 1p are connected to the first and second outlets 2a, 2b of the switching device 2 via the swivel device 4, respectively. Although the conveying pipelines 1p and 1p in the illustrated example are housed and protected in a protective cylinder 1T having a square cross section, the shape of the protective cylinder 1T can be an appropriate shape such as a circular cross section. Further, the protective cylinder 1T can be omitted.

The swivel device 4 has an upper fixed portion 5 which does not rotate and a lower rotary portion 6 which is connected to the lower surface thereof in an airtight manner and rotatably around the vertical axis, similarly to the known device. However, the internal pipe line structure is completely different from the known one.

That is, the upper fixing portion 5 of the swivel device 4 has a pair of conduits 7A and 7B.
A and 7B are the first outlet 2a and the second outlet 2a of the switching device 2.
Of the inlet side portions 7i and 7n, which are respectively connected to the outlets and outlets 2b. Further, one of the conduits 7B has a circular outlet 7x that gradually approaches the rotation center line of the lower rotation unit 6 as it goes toward the connection surface side with the lower rotation unit 6 and is coaxial with the rotation center line on the connection surface. , The other conduit 7A is gradually deformed so as to surround one conduit 7B toward the connecting surface side with the lower rotating part, and coaxially surrounds the circular outlet 7x of the one conduit 7B at the connecting surface. It has an annular outlet 7e.

On the other hand, the internal pipe of the lower rotating portion 6 of the swivel device 4 is constructed so as to be plane-symmetrical to the upper fixed portion 5. That is, the lower rotary unit 6 has a pair of pipelines 8A, 8B, and the pair of pipelines 8A, 8B are arranged in a side-by-side arrangement connected to the pair of transport pipelines 1p, 1p of the improved rod, respectively. While having the side portions 8e, 8x, one of the conduits 8B gradually approaches the rotation center line toward the connection surface side with the upper fixed portion 5, and has a circular inlet 8n that is coaxial with the rotation center line at the connection surface. Having, the other conduit 8
A gradually deforms so as to surround one of the conduits 8B toward the connecting surface side with the upper fixed portion 5, and the annular inlet 8i coaxially surrounds the circular inlet 8n of the one conduit 8B on the connecting surface. Have.

In the swivel device 4 of the present invention,
The circular outlets 7x and the circular inlets 8n and the annular outlets 7e and the circular inlets 8i on the connecting surface between the upper fixed portion 5 and the lower rotating portion 6 and the circular outlet 7e and the circular inlet 8i are symmetric with respect to the connecting surface, and It is configured to always communicate regardless of rotation.

In this way, individual solidified material conveying paths are formed which are always in communication with the upper and lower injection ports 1u and 1b of the rotating improved rod 1. Moreover, in the present invention, in the solidified material conveying path from the switching device 2 to the upper and lower injection ports 1u, 1b of the improved rod 1, only the connecting surface portion in the swivel device 4 has a double pipe structure, and the swivel device 4 is connected to the inlet side. Since the part and the outlet side part are arranged side by side, the conveying pipelines in the improved rod 1 can be arranged side by side. Therefore, the structure of the improved rod 1 can be simplified and the solidified material can be injected with good balance. Further, since the pair of pipe lines 7a, 7b, 8a, 8b in the swivel device 4 gradually change to a double pipe shape as they approach the connecting surface, the solidifying material can smoothly pass without adhering or accumulating. There is also.

Although not shown, in the improved rod 1 of the present example, the solidified material injection ports 1u and 1b were provided only in the upper and lower portions, but as long as these upper and lower injection ports 1u and 1b are provided, another An injection port can be provided at the position. In this case, the switching device 2 also similarly has the outlets 2a and 2b.
It is also possible to further increase the number of the nozzles and switch supply of the solidifying material to three or more injection ports.

On the other hand, when the ground improvement device thus constructed is used, as shown in FIG. 9, it is possible to perform ground improvement without a tip side unimproved portion. That is, first, FIG.
As shown in (c), the improved rod 1 is rotated about its axis, and the ground is cut and agitated while being inserted until the lower injection port 1b reaches the lower end B of the depth direction improved range in the ground to be improved. At this time, as shown in FIG. 9A, the lower injection port 1b is located at a position above the lowermost end B of the depth direction improvement range by a separation distance L between the lower injection port 1b and the upper injection port 1u.
After that, the other opening of the switching conduit 2P in the switching device 2 is connected only to the first outlet 2a (see FIG. 1, the state shown by the solid line in the figure), and the solidifying material is reached. The compressed air from the pressure-feeding device 3 together with the solidifying material for the granular material is transferred to the lower injection port 1b.
Rotate the improved rod while spraying from the chisel. Therefore, as shown in FIGS. 9B and 9C, it is possible to inject the solidifying material up to the lower end B of the stirring range and perform stirring and mixing with the soil at the current position. In FIG. 9, the improved region when the rod is inserted is indicated by reference numeral A1.

Thus, the improved rod 1 is moved to the lower end B of the improved range.
Once it has been inserted up to this point, the improvement rod 1 is then pulled up to the upper end (not shown) of the improvement range. In this case,
As shown in (c) to (e), in the switching device 2, the other opening of the switching conduit 2P is connected only to the second outlet 2b (see FIG. 1; the state shown by the dotted line in the figure). Then, the improved rod 1 is rotated and pulled up while injecting the compressed air accompanied by the solidified material of the granular material from the solidified material pressure feeding device 3 from only the upper injection port 1u. Thus, the pulling-up improvement region A2 on the upper side of the rod-insertion improvement region A1 is also improved, and the improved body can be formed in the entire stirring portion. In addition,
Since the improved area A1 at the time of rod insertion is re-stirred by the pulling rotation of the improved rod 1, the improved area A at the time of pulling is improved.
Stir-mixing is performed to the same extent as 2 to form a uniform improved body in the depth direction. Further, when switching between the upper and lower injection ports 1u and 1b, the solidification material transport path for either one of the injection ports is communicated with the casing 2C of the switching device 2, so that the solidification material transport path for the corresponding injection port is provided. As a result, powder, groundwater, and soft soil may flow back, but such backflow can be prevented if the pressure inside the casing 2C is appropriately maintained by a pressure holding means that keeps the pressure at a predetermined level or higher. It is possible. The internal pressure of the casing 2C can be appropriately determined, but it is preferable that the internal pressure of the casing 2C be equal to or higher than the pressure for feeding the solidifying material.

<Regarding Powder and Granules Pressure Feeding and Supplying Device> Next, the powdery and granular substances pressure feeding and supplying device of the present invention which can be suitably used in the ground improvement method and device will be described in detail. 11 and 12 show a first mode of the powdery-particles pressure-feeding and supplying device according to the present invention. This powder and granular material feeder is mainly used for
The powder metering and supplying means 10, the first opening / closing valve 20, the intermediate chamber 30, the second opening / closing valve 40, the pressure feeding chamber 50, the feeding means 60 and the low level detecting means 51 are included.

The powder and granular material metering and supplying means 10 has a storage chamber 11 having a powder and granular material supply port 11i at an upper part and a discharge port 11x at a lower end, and a powder and granular material supply provided from the outside in the storage chamber 11. As a measuring container 12 configured to receive and store powder and granules through a mouth and discharge the stored powder and granules to the outside, and as a measuring means for measuring the amount of powder and granules in the measuring container 12. Load cells 13, 13. As can be understood from this configuration, the apparatus of the present invention is provided with an upper powdery particle supply port 11 of the powdery particle supply means 10.
With respect to i, for example, it is assumed that the granular material is supplied from a large storage tank (not shown) such as a silo having a supply opening / closing device on the outlet side.

Particularly in the first embodiment, the storage chamber 11
The exhaust filter 14 is communicated with the upper part of the. In addition, the weighing container 12 has a shape in which the upper surface is opened, and one ends of the rotating shafts 15 are connected to both side surfaces,
The other ends of these rotary shafts 15 and 15 are connected to rotary drive sources 16 and 16 such as motors, respectively.
Reference numerals 6 and 16 are fixed to inner side plates 17 and 17 suspended and supported via load cells 13 and 13 from the inner surface of the top plate 11u of the storage chamber 11. Therefore, the weighing container 12 is suspended in the storage chamber 11 via the load cells 13 and 13, and the amount of powder and granules therein can be measured by the load cells 13 and 13. Further, the rotation driving sources 15 and 15 invert it. As a result, the stored granular material inside can be discharged. The state after inversion is shown by a dotted line.

An intermediate chamber 30 is connected to the lower end discharge port 11x of the storage chamber 11 via a first opening / closing valve 20, and a second opening / closing valve 40 is connected to the lower end discharge port 30x of the intermediate chamber 30. The pumping chamber 50 is connected via the. As the on-off valves 20 and 40, as shown in the drawing, rotary shafts 22 and 42 along the horizontal transverse direction are provided in the pipe lines 21 and 41, and the rotary shafts 22 and 42 are plate-shaped so as to be able to close the pipe line 21. The valve bodies 23, 43 are attached, and the rotary shaft 22,
A device provided with 32 rotary drive sources 24, 44 can be used. In the illustrated example, the reciprocating driving force of the cylinders 25 and 45 is mechanically converted to the rotational direction of the rotary shafts 22 and 32 and transmitted to the rotary shafts 22 and 42. On the other hand, since each of the chambers 11, 30 and 50 conveys the granular material by its own weight drop, it is desirable to use a cylindrical body whose inner diameter becomes smaller toward the lower end as shown in the figure.

Particularly, a low level sensor 51 is provided at a predetermined height position in the pressure feeding chamber 50, and the low level sensor 51 prevents the powder or granular material in the pressure feeding chamber 50 from reaching a predetermined amount. The level status can be detected. The height position of the low level sensor is, for example, from the time when the low level state is detected until the time when the powder particles are replenished in the pressure feeding chamber 50, the external feeding means 6
0 is the height position corresponding to the amount of powder and granules sufficient to continuously and quantitatively supply the powder and granules.

Further, the pressure feeding chamber 50 is provided with a feeding means 60 for continuously taking out a predetermined amount of the powder or granular material stored therein, placing it on the pressurized air and sending it to the outside.

The external feeding means 60 is, for example, as shown in the figure, a rotor case portion 61 continuous from the lower end portion of the pressure feeding chamber 50, and is continuously driven to rotate in a predetermined direction inside the rotor case portion 61. It can be constituted by a continuous fixed-quantity supply type rotary feeder composed of the rotor 62 and a delivery unit for delivering the powder or granules cut out by the rotary feeder on the compressed air from a compressed air supply source such as a compressor (not shown). The rotor 62 is
It is rotatable around a laterally (or horizontally) rotating shaft 63, and a large number of partition blades 64 projecting in the radial direction are formed on the outer peripheral surface of the rotating shaft 63 at equal intervals in the circumferential direction. The space is formed as a pocket 65. The rotary shaft 63 is connected to a rotary drive source such as a motor (not shown) that is connected to the outside of the case 61, and the rotor 62 is rotated by the rotary drive source. Of course, in the present invention, a rotor having another known shape may be used. Also, as the sending unit,
As shown in the drawing, a powder / granular material outlet 66 is formed at the lower end of the side surface of the rotor case 61 that is orthogonal to the direction of the rotation axis 63 of the rotor 62, and compressed air from a compressed air supply source is provided at the lower end of the side surface facing this. It is possible to adopt a configuration in which the introduction port 67 is formed and the compressed air from the compressed air introduction port 67 circulates to the powder and granule delivery port 66 via the pocket 65 at a position corresponding to these.

Further, the one using the screw feeder described in JP-A-8-113370, and Japanese Patent Application No.
No. 01-233135 and FIGS.
As shown in FIGS. 11A to 11C, it is possible to use a device that can continuously supply a fixed amount to a plurality of external delivery paths.

On the other hand, in the first embodiment, the measuring container 12
The amount of powder and granules in the weighing container 12 can be measured by supporting the powder and granules in the storage chamber via a load cell. However, as shown in FIGS. The entire weighing and supplying means 10 is suspended and supported by a load cell 13 with respect to a gantry 70 (only a part of which is shown), and the weighing container 12 is deducted by subtracting the weight of the apparatus.
It may be configured so that the amount of powder and granules therein can be measured. In this case, the storage chamber 11 of the powder and granular material metering means 10 and the first opening / closing valve 20 are connected by a flexible joint (for example, a resin bellows tube made of rubber or the like) 80 that can be expanded and contracted in the vertical direction. The lower part than the on-off valve 20 is a stand 7 separately.
Fixed to 0. Further, in this case, as shown in the drawing, the rotary shaft 15 of the weighing container is communicated with the outside of the storage chamber and is connected to the rotary drive source 16 fixed to the outer peripheral surface of the storage chamber 11, and the inner side plate 17 can be omitted.

In the first embodiment, the measuring container 11
Is configured to discharge the stored powder and granules by inversion, but like the third embodiment shown in FIG. 15 and the fourth embodiment shown in FIG.
1 and the powder and granular material discharge port 92 is formed at the lower end,
It is also possible to use a hopper-shaped measuring container 90 having an opening / closing valve at the lower end discharge port 92. The on-off valve engages and disengages from the discharge port 92 by vertically moving the cone-shaped valve body 93 fixed to the top plate 11u and the cone-shaped valve body 93 fitted into the discharge port from the lower side as illustrated. And a cylinder 94 for Moreover, the method of suspending the measuring container 12 is different between the third mode and the fourth mode, and the former is the measuring container 1
2 adopts a powder and granular material measuring structure corresponding to the first embodiment in that the powder and granular material measuring and supplying means 10 is supported on the gantry 70. On the other hand, it is suspended and supported via a load cell 13, and the storage chamber 11 of the powder and granular material measuring and supplying means 10 and the first
The present invention adopts the powder and granular material measuring configuration corresponding to the second embodiment in that the open / close valve 20 and the flexible valve 80 are connected.

On the other hand, the operation mode of the powder and granular material pressure-feeding apparatus of the present invention thus constructed is as shown in FIG.
Note that FIG. 17 representatively shows the case of the apparatus of the above-described third mode, but the same applies to the case of the apparatus of other modes. (At the time of starting the apparatus) At the time of starting the apparatus, first, the external sending means 60.
Without external delivery by means of at least the rotary feeder,
Each of the intermediate chamber 30 and the measuring container 11 is in a state of storing a predetermined amount of powder or granular material (not shown).

Therefore, first, the powder or granular material is charged and supplied from the large external storage tank such as a silo into the measuring container 90 through the supply port 11i. At this time, the weighing cell 90 is loaded by the load cell 13.
The amount of powder and granules inside is measured, and when it reaches a predetermined amount, the supply from the outside is automatically stopped. When the weighing is completed, the on-off valve of the weighing container 90 is opened to discharge the powdery particles inside the storage chamber 11, and the first on-off valve 20 and the second on-off valve 30 are appropriately opened and closed, so that the intermediate Chamber 30
The powder or granular material is fed to the pressure feeding chamber 50 or the pressure feeding chamber 50. If necessary, the powder or granular material can be supplied from the external storage tank a plurality of times. When each of the pressure feeding chamber 50, the intermediate chamber 30, and the measuring container 90 has already stored a predetermined amount of powder or granular material, it is not necessary to perform the operation at the time of starting the apparatus.

(During External Supply of Powders and Granules) During the external supply of powders and granules, the external feeding means 60 is constantly operated to continuously feed a fixed amount to the outside. More specifically, FIG.
As shown in FIG. 3, the rotor 62 of the rotary feeder is continuously rotated in a predetermined direction, and the powder particles P3 stored in the pressure feeding chamber 50 are sequentially received in the pockets 65 of the rotor 62, and the rotor 62 rotates. And is transferred to the delivery port 66 side. On the other hand, compressed air is introduced from a compressed air supply source (not shown) into the pocket 65 communicating with the compressed air inlet 67. As a result, the granular material P4 received in the pocket 65 is carried on the pressure air passing through the pocket 65 when the pocket 65 does not communicate with the pressure feeding chamber 50 and communicates with the lower port outlet 66. It is sent to the outside via 66. Most of the compressed air is sent out together with the powdery particles, but the rotor pocket 65 after the transfer of the powdery particles is circulated to the pumping chamber side by the rotation of the rotor 62. Pumping chamber 50
It leaks inside a little.

By such external delivery, the pressure feeding chamber 50
When the storage amount of the powder or granular material P3 in the inside decreases as shown in FIG. 17A and the low level detecting means 51 detects the low level state, as shown in FIG.
The second on-off valve 40 is opened for a predetermined time while the on-off valve 20 is closed, and the powder particles stored in the intermediate chamber 30 are dropped and supplied to the pressure feeding chamber 50. At this time, a part of the compressed air leaking into the pressure feeding chamber 50 slightly leaks into the intermediate chamber 30.

When the opening / closing operation of the second opening / closing valve 40 is performed, subsequently, as shown in FIG. 17 (c), in this example, the first opening / closing valve 20 is opened with the second opening / closing valve 40 closed. After being opened for a predetermined time, the compressed air in the intermediate chamber 30 is sent into the storage chamber 11 and exhausted to the outside of the apparatus through the exhaust filter 14. At this time, the powder P in the storage chamber 11
Since 1 is stored in the measuring container 90, the compressed air passing through the storage chamber 11 hardly acts. Therefore,
In the apparatus of the present invention, the compressed air is appropriately exhausted, and the situation in which the powder or granular material flows backward is unlikely to occur.

Then, as shown in FIG. 17D, the second
With the opening / closing valve 40 closed, the first opening / closing valve 20 is opened, and the intermediate chamber replenishing operation is performed in which the weighed powder and granules stored in the weighing container 90 are discharged and supplied to the intermediate chamber 30. Further, subsequently, as shown in FIG. 17 (e), with the first opening / closing valve 20 closed, the acceptance of the powder or granular material from the outside into the weighing container 90 is started and the weighing by the load cell 13 is performed. A predetermined amount of powder or granular material is received in the container 90 (measurement container replenishing operation). These replenishment operations may be alternately repeated a plurality of times as needed when the replenishment amount is designed to be small at one time.

Therefore, in this case, until the powder or granular material in the pressure feeding chamber 50 reaches the low level, the intermediate chamber 30
The volume, low-level position, replenishment amount, etc. of the pumping chamber 50 are properly designed so that the replenishment to the replenishment is completed. In other words, the shortest supply time to the intermediate chamber 30 and the time until the storage amount of the pumping chamber 50 reaches the low level are equal to each other, which is the maximum pumping capacity of this device.
However, in this metering container supply operation, it is sufficient if at least the first on-off valve 20 is closed. Therefore, if the storage amount of the pumping chamber 50 becomes (or becomes) at a low level during this operation, in parallel. It is also possible to open the second opening / closing valve 40 to perform the pressure feeding chamber replenishing operation.

Thus, during the external pressure feeding of the powder or granular material, a predetermined amount of the powder or granular material is stored in the intermediate chamber 30 and the measuring container 90, and the powder or granular material is supplied to the pressure feeding chamber 5 as necessary.
It is gradually supplied toward 0. This is repeated thereafter.

The powdery-particles pressure-feeding / supplying device of the present invention thus constructed has the following advantages. (A) Since the powder and granules are pressure-fed after being weighed by the weighing container 90 (indicated by reference numeral 12 in the first and second embodiments) and the weighing means 13, it is possible to easily record the amount of powder and granules used. Can be done accurately. (B) Since it is not necessary to store a large amount of powder or granules in the device, the device can be downsized. Even in this case, a large-scale storage device for storing the granular material is used except for the case of small-scale construction, so that there is no problem in practical use. (C) The compressed air in the device is appropriately exhausted by the appropriate valve opening / closing timing according to the above procedure, and the backflow of the powder or granules is unlikely to occur. (D) In the present invention, since the two solidification material supply paths are blocked by the two on-off valves 20 and 40 at intervals,
It has a very simple structure, and maintenance such as internal cleaning is very easy.

[0060]

As described above, in the ground improvement method and apparatus of the present invention, advantages such as reliable switching of the solidifying material injection can be brought about while having a simple structure and mechanism. In addition, the pressure-feeding and feeding device for powders and granules can reliably prevent backflow of powders and granules by compressed air, has a simple structure and mechanism, and is extremely easy to maintain such as cleaning the inside, and is compact and has a large capacity. It is possible to carry out pressure feeding of the powder, and it is possible to easily and accurately control the amount of the powder or granules used, and so on.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a ground improvement method and device of the present invention, and in particular, a cross section of a switching device.

FIG. 2 is a vertical sectional view of a switching device of the present invention.

FIG. 3 is a partially cutaway view showing an example of a suitable ground improvement rod.

FIG. 4 is an enlarged view of part A of FIG.

5 is a sectional view taken along line BB of FIG.

FIG. 6 is an enlarged view of part C in FIG.

FIG. 7 is an enlarged view of part D in FIG.

FIG. 8 is an enlarged view of a portion E in FIG.

FIG. 9 is a diagram showing a construction procedure of the ground improvement method of the present invention.

FIG. 10 is a diagram showing a construction procedure of a conventional ground improvement method.

FIG. 11 is a vertical cross-sectional view of a first embodiment of a powder and granular material pressure-feeding device according to the present invention.

FIG. 12 is a vertical cross-sectional view of the first mode in another direction.

FIG. 13 is a vertical cross-sectional view of a second form of the powdery-particles pressure-feeding and supplying device according to the present invention.

FIG. 14 is a vertical cross-sectional view of the second mode from another direction.

FIG. 15 is a vertical cross-sectional view of a third embodiment of a powder and granular material pressure feeding and supplying device according to the present invention.

FIG. 16 is a vertical cross-sectional view of a fourth embodiment of a powder and granular material pressure feeding and supplying device according to the present invention.

FIG. 17 is a diagram showing an operation procedure of the powdery-particles pressure-feeding and supplying device according to the present invention.

FIG. 18 is an enlarged view of the essential parts showing the operating procedure of the powdery-particles pressure-feeding and supplying device according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Improved rod, 2 ... Switching device, 3 ... Powder / solidified material pressure-feeding / supplying device, 4 ... Swivel device, 10 ... Powder / granular material measuring and supplying means, 11 ... Storage chamber, 12 ... Measuring container, 13 ... Load cell, 14 ... exhaust filter, 20 ... first on-off valve,
30 ... Intermediate chamber, 40 ... Second opening / closing valve, 50 ... Pressure feeding chamber, 51 ... Low level detecting means, 60 ... External feeding means.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2D040 AA01 AB05 BD05 CB01                 3F047 BA02                 3F075 AA08 BA10 BB01 CA04 CA06                       CB01 CB05 CB11 CD03

Claims (4)

[Claims] 1. An improved rod having a lower injection hole provided at a lower end portion, an upper injection hole provided above the lower injection hole, and a stirring blade provided in a range extending from the lower injection port to the upper injection port. A casing having a supply port into which compressed air accompanied by a solidifying material is blown, a first outlet port connected to the lower injection port, and a second outlet port connected to the upper injection port, One opening was connected to the supply port in the casing, and the other opening was movable to each of the connection position with the first delivery port and the connection position with the second delivery port. A switching device having a switching pipe line and a pressure holding means for keeping the pressure in the casing at a predetermined level or higher, and supplying compressed air accompanied by the powdery solidification material to the improved rod via the switching supply device. A pressure feeding device, Using the ground improvement device provided; while rotating the improvement rod about its axis, after inserting the lower injection port until reaching the lower end of the depth direction improvement range in the ground to be improved, at least the upper injection port While pulling up until reaching the upper end of the depth direction improvement range, in the insertion process of the improvement rod, the lower injection port, the separation distance between the lower injection port and the upper injection port from the lowermost end of the depth direction improvement range. When the upper position is reached by a minute, the other opening of the switching pipe is connected only to the first delivery port, and the compressed air from the solidified material pressure-feeding device with the solidified material of the granular material is reached. Is injected only from the lower injection port, the improved rod is rotationally inserted, and in the process of pulling up the improved rod, the other opening of the switching pipe is connected only to the second outlet. The improved granular material is rotated and pulled up while the compressed air from the solidified material pumping device from the solidified material pumping device is injected only from the upper injection port. Ground improvement method using. 2. An improved rod having a lower injection hole provided at a lower end portion, an upper injection hole provided above the lower injection hole, and an agitating blade provided in a range extending from the lower injection port to the upper injection port. A switching device that is connected to each of the lower injection port and the upper injection port and switches between supply of the granular material solidifying material to the lower injection port and supply of the granular material solidifying material to the upper injection port; A ground improvement device, comprising: a pressure-feeding supply device that supplies compressed air accompanied by a granular solidifying material to the improvement rod via the switching supply device, wherein the switching device includes; A casing provided with a supply port into which compressed air accompanied by a solidifying material is blown, a first outlet connected to the lower injection port, and a second outlet connected to the upper injection port, respectively. This In the casing, one opening is connected to the supply port, and the other opening is movable to each of the connection position with the first delivery port and the connection position with the second delivery port. And a driving means for giving a moving force to the switching pipeline, and a pressure holding means for keeping the pressure in the casing above the pressure of the solidified material from the solidified material pumping device. In addition, the ground improvement device using the powder and particle solidifying material. 3. The improved rod is provided with a pair of side-by-side transfer pipelines that are respectively communicated with the lower injection port and the upper injection port and that extend to the upper end along the rod longitudinal direction. The pipe lines are respectively connected to the first outlet and the second outlet of the switching device via a swivel device, and the swivel device includes an upper fixing portion and a lower surface thereof in an airtight and vertical manner. It has a lower rotating part that is rotatably connected around an axis, and the upper fixed part of this swivel device has a pair of pipe lines,
The pair of pipelines have horizontally-arranged inlet-side portions respectively connected to the first outlet and the second outlet of the switching device, and one pipeline is connected to the lower rotating portion. As it goes toward the surface side, it gradually approaches the rotation center line of the lower rotation part and has a circular outlet coaxial with the rotation center line at the connection surface, and the other pipeline goes to the connection surface side with the lower rotation part. As a result, it has an annular outlet that gradually deforms so as to surround the one conduit and coaxially surrounds the circular outlet of the one conduit at the connection surface, while the lower rotating part of the swivel device has a pair. And a pair of pipelines each have a side-by-side outlet side portion connected to the pair of transport pipelines of the improved rod, and one pipeline is connected to the upper fixing portion. As you go to the connection side Gradually approaching the rotation center line,
And has a circular inlet coaxial with the rotation center line on the connection surface, and the other pipeline is gradually deformed so as to surround the one pipeline toward the connection surface side with the upper fixing portion, and is connected. Has a circular inlet coaxially surrounding the circular inlet of the one conduit in the plane, the circular outlet and circular inlet mutual and the circular outlet and circular inlet mutual in the connecting surface of the fixed portion and the rotating portion,
The ground improvement device using the powder and granular material solidifying material according to claim 2, each of which is symmetric with respect to the connection surface and is configured to be always communicated with each other. 4. A storage chamber having a powder supply port at the upper part and a discharge port at the lower end, and a powder chamber which is provided in the storage chamber and receives the powder from the outside through the powder supply port. Means for supplying and measuring powder and granules, comprising: a measuring container configured to discharge the stored and stored powder and granules into the storage chamber; and a measuring means for measuring the amount of powder and granules in the measuring container. An intermediate chamber that is connected to the lower end outlet of the storage chamber via a first on-off valve and has an outlet at the lower end; and a second chamber for the lower end outlet of the intermediate chamber. A pressure feeding chamber connected via an on-off valve, a feeding means for continuously taking out a predetermined amount of powder and granules stored in the pressure feeding chamber, and sending the powder and granules to the outside by placing them on the pressure air; Lore level with a certain amount of body retention And a low level detecting means for detecting a low level state which has not reached the maximum level; at the time of the operation of supplying the granular material to the outside, the sending means is always operated to perform continuous fixed amount sending to the outside, When the low level state is detected by the low level detecting means, the second open / close valve is opened with the first open / close valve closed to supply the granular material in the intermediate chamber to the pressure feeding chamber. Perform the pressure chamber replenishment operation to
Thereafter, the first opening / closing valve is opened while the second opening / closing valve is closed, and at the same time, the intermediate chamber replenishing operation for discharging the powder or granular material stored in the measuring container to supply the intermediate chamber, and at least the above A powder and granular material pressure-feeding device configured to perform a weighing container supply operation for receiving a predetermined amount of powder or granular material from the outside into the weighing container with the first on-off valve closed.