JPH05179637A - Pulverulent body injecting and stirring method and its device - Google Patents

Abstract

PURPOSE:To eliminate possibilities of environmental destruction or the like by forming a tube-shaped shield made of a pulverulent improved material along the outside surface of a cylindrical body of the excavated soil, and discharging the gas to be fed for the gas-borne transportation upward inside the shield. CONSTITUTION:When a sleeve 13 is subject to the excavating resistance and the earth pressure when the lower stage blade 5' is rotated in an integrated manner with a hollow pipe 4 in the descending process, and excavates the ground 1, the sleeve is elevated through a spline mechanism 4. In a process where the sleeve is pulled upward in the ground 1, the sleeve is lowered at the specified stroke, while in the descending excavation process, through the valve switching operation relative to the on-the-ground gas-borne transportation passage 10 which is not indicated in the figure, a small amount of pulverulent body is supplied from a nozzle port 10' to an injection nozzle 11', and injection is made from a curved nozzle 16' downward of the external end part, a tube-shaped shield 6' is formed. In the elevating process of the lower stage stirring blade 5', the pulverulent body of the specified amount is injected from the injection nozzle over the entire area within the stirring blade 5' with the concentration as uniform as possible to make stirring and blending with the soil and form the cylindrical resistant body, to protect the external surface smoothly, to form a secure resistant body, preventing the escape of the air, the transporting gas therebetween, into the gravel layer 9.

Description

Detailed Description of the Invention

[0001]

[Field of Industrial Application] The disclosed technology belongs to the field of technology for improving soft ground such as rivers, lakes and marshes and shallow beaches by injecting powder such as cement into the ground.

[0002]

2. Description of the Related Art As is well known, effective use of land is extremely important in Japan, where the land is narrow, and various construction techniques have been researched and improved and have been put to practical use since long ago. There is.

However, in the reality that there are many mountainous and forest areas topographically and the plains are scattered along the vicinity of the invaded coastline, in the reality, various facilities are concentrated in existing areas. From this point of view, there is a limit to the development of vast forests and wilderness areas from the viewpoints of environmental protection and nature conservation. Therefore, the development and utilization of so-called soft ground in river basins such as rivers, lakes and shores is significant. In addition, land reclamation, reclamation, and dredging in these areas have been combined and put to practical use as effective construction.

Further, the ground improvement is not limited to the soft ground, and the ground may be improved in accordance with the renovation or demolition of many existing facilities such as structures.

As is well known to those skilled in the art, in the improvement work of such soft ground, a hollow pipe is used for excavation and drilling in the ground, and a predetermined improvement material is provided in the ascending or descending process. The technique of injecting into the ground to achieve solidification over time is used, and up until now, the improvement work by injecting a drug solution with a specified gel time has been mainly used, and a drug solution such as water glass has been adopted. It was

However, pollution problems such as groundwater pollution have come to be highlighted, and the improvement work by injecting such chemicals is gradually restricted by various conditions. Instead of this, powders of cement, quick lime, slag and the like are used. The powder injection agitation technology, which injects the improved material in the ground into the ground and mixes it with the excavated soil through the agitation action to solidify over time, has been put to practical use, especially in the improvement of the ground such as middle and deep layers. Achievements are becoming available.

[0007] Further, depending on the intended use, the powder to be sprayed may be industrial waste such as the above-mentioned slag,
It also has the merit of being able to help solve pollution problems.

[0008]

By the way, in order to transport such a powder improving material from the ground to be jetted into the ground at a predetermined depth, the powder improving material itself may be clogged with a bridge or the like. Since it is impossible to carry out pressure feeding in the hollow pipe, generally, a method of gas transportation via a gas such as air is predominant.

Further, not only industrial waste such as cement, quick lime and slag, but also technical improvements that can be used in the form of slurry have been developed as powders. For example, Japanese Patent Publication No. 3-60969. As mentioned above, research has been conducted to improve the improvement efficiency.

By the way, the ground improvement work by the powder injection stirring has a peculiarity because the powder as the improving material is gas-transported, and the ground is mediated by a stirring blade provided at the tip of the hollow pipe. In the descending process, and in the ascending process, the powder is transported from the gas transport passage of the powder provided in the hollow pipe into the ground by the injection nozzle provided at the base of the stirring blade, etc., and is excavated by the stirring blade. The material that was stirred and mixed together with the soil was formed into a cylindrical material that solidified over time, and the gas used for transportation was discharged to the ground. At the same time, the surplus powder or fine powder in the ground itself is mixed in a floating state, so if it escapes directly on the ground surface,
As shown in FIG. 12, the dustproof hood 2 is set on the ground surface 1 ′ of the ground, and the hollow pipe 4 is inserted through the seal 3 thereof, because there is a risk of causing pollution such as air pollution in the work environment and the surroundings.
Is allowed to ascend and descend, and the stirring blades 5 and 5 fixed to the tip of the hollow pipe 4 excavate in the descending process and agitate and mix with the powder in the ascending process. The gas supplied for transportation rises to the ground surface 1 ′ along the side surface of the hollow pipe 4, etc., and the powder component is removed from the inside of the hood 2 via the discharge pump 7 by the filter device 8 such as a bag filter to be cleaned. He was trying to dissipate only the air into the atmosphere.

By the way, the ground 1 is generally made up of a plurality of strata such as a negative rock layer and a gravel layer. Although the rising gas does not diffuse sideways in the negative rock layer, etc.
As shown in, when the gravel layer 9 is present, the gas used for transporting the powder does not always rise only from the cylindrical soil 6 portion, and escapes into the gravel layer 9 due to the pressure condition, There is a risk that the low pressure part of the gravel layer 9 will rise to the ground surface 1'and dissipate into the air, and if a phenomenon that the transported gas is arbitrarily ejected occurs on private land and various facilities, so-called inhabitant power, etc. It becomes a problem, it is difficult to achieve smooth construction, and the amount of powder that is set is insufficiently sprayed to a prescribed site, or it may lead to complaints such as insufficient supply. There was

[0012] In the process of forming a columnar pile body which is important for ground improvement, unless the powder improving material is sufficiently mixed in the agitated soil inside the pile body in advance, the strength is insufficient on the outer surface of the pile body. It is impossible to form a columnar body that is the basis of the pile body formation as designed due to damage due to damage, etc., and gas leakage is unavoidable in the cylindrical soil and the stirring and mixing process of powder to the soil. There was also.

The problem is that the target improved ground is the middle layer,
The deeper it was, the more likely it was.

Therefore, in the powder jet agitation construction, the transported gas can be reliably discharged and dust can be removed only from the surface portion near the hollow pipe, and in addition, air can be diffused through the gravel layer or the like. Despite the widespread demand for construction technology that does not exist, there has been a problem that the improved technology so far cannot deal with this.

[0015]

OBJECTS OF THE INVENTION The object of the invention of the present application is to disperse gas in the process of ascending gas, such as air, used for powder transportation in ground improvement by jet agitation of powder improving materials such as cement based on the above-mentioned prior art The technical problem that should be solved is
A tubular shield is formed on the outer surface of the cylinder of the agitated soil that forms the final construct in the hollow pipe insertion process through the excavation of the agitator blade in the ground, and the side of the powder transport gas to the gravel layer etc. Civil engineering in the construction industry to prevent accidental dispersal to the section, prevent troubles due to damage to the outer surface of the pile body of the columnar body, and perform ground improvement as designed with sufficient strength. An object of the present invention is to provide an excellent powder jet agitation method that is useful in the technical application field, and an apparatus directly used in the method.

[0016]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the structure of the invention of this application, which has the above-mentioned object as its gist, has been designed in order to solve the above-mentioned problems. When improving the ground by spraying powder improving material,
A predetermined hollow pipe is inserted into the ground, and excavation is performed by a stirring blade integrally provided at the tip of the hollow pipe, and in the descending process, for example, in the lower stirring blade, Drilling is performed by gas-transporting a powder improving material such as cement with a gas of a predetermined pressure from a powder injection nozzle curved downward at the outer end through a powder transport passage provided inside the hollow pipe. In the rising process, a tubular shield is formed on the outer surface of the cylindrical body of soil in the area, and in the ascending process, the stirring blade is agitated by another powder ejection nozzle provided along the longitudinal direction of the stirring blade. Spray the powder into the area to ensure agitation with the excavated soil, mix as evenly as possible, and do not spray the powder in the descending process again, and again in the ascending process. So that the injection is done Therefore, the tube-shaped shield formed by the powder firstly rises in the excavation area and mixes on the ground so that the gas used for the powder rise does not diffuse into the gravel layer etc. In order to remove the powder that has been removed and to disperse it into the atmosphere as a clean gas, the cylindrical outer surface of the pile body is surely formed with a tubular shield so that the strength of the pile body is sufficiently maintained, The outer surface is prevented from being damaged or the like, and when the tubular shield is formed of the above powder, the stirring blade is slid on the rotary shaft of the hollow pipe and the stirring blade is provided with a vertical phase difference. Desirable to switch powder injection in ascending process or descending process, to perform by cylinder or valve, and to form tubular shield through expansion and contraction by slide blade It is certainly what ground improvement has taken technical means to allow as can be performed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the invention of this application will be described below with reference to FIGS.

It is to be noted that the same aspects as those in FIG. 12 will be described using the same reference numerals.

The embodiment shown in FIGS. 1 to 5 is an embodiment of an apparatus 100 for improving soft ground 1 by means of two-stage agitating blades 5, and 100 'is a ground improvement by upper and lower agitating blades 5, 5'. This is a mode of the apparatus, and as described above, when a pile body is formed by mixing and stirring the powder improving material and the soil when the gravel layer 9 is layered in the ground 1, the tubular shield 6 is formed on the outer surface thereof.
', The strength of the columnar body of the pile body is sufficiently secured by stirring and mixing, the outer surface is reliably protected, and the air used as the gas for powder transportation during the improvement 1' It is used to perform a shielding action so as not to disperse in the gravel layer 9 in the process of discharging the dust to the outside air from the hood 2 by the filtering device 8 and dissipating to the outside air, and the embodiment shown in FIG. Then, the hollow pipe 4 is rotated and excavated by the stirring blade 5 in the descending process. After excavating to a predetermined depth, the injection nozzle 1 provided in the stirring blade 5 is switched to the ascending process.
A relatively small amount of powder improving material is sprayed from 1'to form a thin tube-shaped shield 6'at the tip of the stirring blade 5, and a relatively large amount is produced in the second descending process. The powder of the powder is blown out by gas, and mixed with the excavated soil by stirring to solidify and form the solid cylindrical piles in the tubular shield 6'which was previously formed. The gaseous air used for body transport is shielded by the preformed tubular shield 6 ′ and does not escape to the gravel layer 9, and therefore rises in the drill hole and, as shown in FIG. The powder is removed from the inside by a filter device 8 via a pump 7, and is normalized so as to be scattered into the atmosphere.
Therefore, there is no possibility that gas will blow out to the private land outside the improvement area.

The embodiment shown in FIG. 2 will be described in detail with reference to FIGS. 3, 4 and 5. In the powder injection stirring apparatus 100 'having the upper and lower two-stage stirring blades 5, 5', the upper stage is shown. In the stirring blade 5 of FIG. 1, an injection nozzle 11 of a powder improving material such as cement, which is connected to a gas transport passage 10 concentrically provided inside the hollow pipe 4, is extended in the longitudinal direction along the stirring blade 5, A bulkhead 12 is provided at the outer end portion of the blade 5, nozzle nozzles 16, 16 ... Are opened downward at a predetermined pitch in the injection nozzle 5, and the lower stirring blade 5 is provided.
′ Is integrally provided with a sleeve 13 at its base, and the sleeve 13 is slidable with respect to the hollow pipe 4 through a spline mechanism 14 for a predetermined stroke.
The stroke is restricted by 15 ', and the injection nozzles 1 for forming piles are provided in the ports 10', 10 '' provided at the stroke ends of the predetermined pitch and having different phases in the longitudinal direction.
1 and the injection nozzle 11 'for forming the tubular shield 6'
Are selectively connectable.

Thus, the lower blade 5'of the sleeve 13 rotates integrally with the hollow pipe 4 to receive excavation resistance or earth pressure for excavating the ground 1 in the descending process,
Ascends to the hollow pipe 4 via the spline mechanism 14,
Also, in the process of being pulled up in the ground 1, the stroke is lowered by a predetermined stroke, and the gas transport passage 10 on the ground (not shown).
In the descending excavation process by switching the valve with respect to, a small amount of a predetermined amount of powder is supplied from the nozzle port 10 'to the injection nozzle 11', and is injected from the downward bending nozzle 16 'of its outer end, as shown in FIG. Then, a tubular shield 6'is formed, and a set amount of powder is injected from the injection nozzle 11 to all regions in the stirring blade 5'in the ascending process of the lower stirring blade 5'at a uniform concentration as much as possible. Then, when the mixture is mixed with the soil by stirring to form a cylindrical pile body, the outer surface of the pile body is smoothly protected so that a reliable pile body is formed. Try to prevent the escape of.

Therefore, in this embodiment, the tubular shield 6'can be formed by switching the lower stirring blade 5'up and down during excavation of the ground 1 during the excavation and ascent process of the ground, and depending on the upper stirring blade 5 inside. It is possible to form a solid columnar pile.

It is possible to avoid escape of powder transport gas to the gravel layer 9 in ground improvement, and to form a reliable and sound columnar pile body as designed.

Thus, the above embodiment is a mode in which the lower stirring blade 5'is automatically switched through earth pressure and its own weight in the descending and ascending process, but in the embodiment shown in FIG. On one side of the stirring blades 5 ', 5', a cylindrical pile injection nozzle 11 for forming a pile is provided, and on the other side, a tubular shield 6'forming nozzle 11 '(the tip of which is directed downward as in the above-mentioned embodiment). A curved nozzle 16 'is formed in the hollow pipe 4), and the sleeve 13' is integrally connected to a piston 18 of a cylinder 17 provided inside the hollow pipe 4 on the lower side. Passage 19 and
A port 2 to an injection nozzle 11 communicating with a gas transport passage 10 in the hollow pipe 4 by moving a piston 18, that is, a sleeve 13 'up and down in the hollow pipe 4 via a valve 20.
1 and a port 21 'to the injection nozzle 11' which is selectively switchably connected to provide a tubular shield 6'in the raising process of the hollow pipe 4 and a solid pile body in the raising process. This is a mode in which the entire columnar body is formed by stirring and mixing the soil and the powder, and the action and effect are substantially the same as those in the above-mentioned embodiment.

Next, in the embodiment shown in FIG. 7, each gas dedicated to the upper and lower stirring blades 5 provided on the hollow pipe 4 and the injection nozzles 11 and 11 forming a columnar pile by 5 '. The transportation passages 10 and 10 are fixedly connected to each other, and another gas transportation passage 10 'is connected to the injection nozzle 11' for forming the tubular shield 6'of the lower stirring blade 5 ', and the selection on the ground is performed. Connected to the typical switching valves 22, 22 ',
It is possible to surely form the tubular shield 6'and the solid columnar pile body by a predetermined descending process and ascending process.

In the embodiment shown in FIGS. 8 to 11, when forming the tubular shield 6'which is the main point of the invention of this application, the tip of the stirring blade 5'is displaceable in the longitudinal direction. A slide vane 12 is provided, and a downwardly curved jet nozzle 22 for forming a tubular shield 6 ′ is attached to the slide vane 12 so that the jet nozzle 11 in the stirring vane 5 ′ is provided.
', And, for example, in the descending process of the hollow pipe 4 or in the ascending process from a predetermined depth, a small amount of powder is sprayed to form a tubular shield 6', and the ground shield 1 is formed in the same manner as described above. To prevent escape of air of the transport gas to the gravel layer 9 and to stir and mix the soil and the powder when forming the solid cylindrical body to protect the outer surface when forming the pile body. Tubular shield 6 used for
As shown in the figure, the slide blade 22 is formed at the time of forming the ', and a predetermined amount of the blade is projected outwardly at the outer end of the stirring blade 5', and when the solid cylindrical pile body is formed, the slide is performed from the end to the inside. When the blades 22 are made to retreat and the switching thereof is controlled, another rotary drive shaft 23 is provided in the hollow pipe 4 separately from the gas transport passage 10 in the embodiment of FIGS. The slide blade 22 provided inside the stirring blade 5'is provided with the cam 2 at the end of the rod 25 of the slide blade 22 inside the stirring blade 5 '.
The cam follower roller 26 for 4 is brought into contact with the slide blade 22 so as to move back and forth to the outer end of the stirring blade 5 '.
This is a mode in which the tube-shaped shield 6'is made to advance when it is formed, and is made to recede when the columnar pile body is formed.
In the embodiment shown in FIG. 2, an actuator 27 such as an appropriate cylinder is interposed between the slide blade 22 and the hollow pipe 4 so that the slide blade 22 can be moved back and forth similarly.

Further, in the embodiment shown in FIG. 11, the downward injection nozzle 16 'of the slide vane 22 is opened and closed by an appropriate check valve 28, and the function and effect thereof are obtained by the above-mentioned respective embodiments. There is no substantial difference from the example.

Of course, the embodiment of the invention of this application is not limited to the above-mentioned respective embodiments. For example, the formation of the tubular shield is performed by either the process of descending or ascending the hollow pipe. It is possible to employ various modes such as not only performing the process but also determining in advance depending on the condition of the ground whether to perform the process from the second lifting process.

Needless to say, the number of stages of the stirring blades may be increased to three or more by design modification.

[0030]

As described above, according to the invention of this application, basically, unlike the chemical solution injection in the ground improvement such as the soft ground,
By injecting a powder improving material such as cement into the ground, groundwater contamination can be avoided, and by using powder such as slag obtained by crushing industrial waste, it is possible to add pollution and environmental problems. The effect is reliably maintained, and the air, etc., of the transport gas to the injection nozzle provided along the stirring blade through the powder hollow pipe is prevented from escaping to the gravel layer in the ground, improving the design. An excellent effect is obtained in that there is no fear of environmental destruction due to rising and jetting to the ground outside the area.

Then, the transport gas is jetted from the tip of the stirring blade and a small amount of powder is supplied to the transport gas, so that the transport gas rises in the tube-shaped shield formed in the powder and gravel and gravel. It has the effect of forming an ascending path for the transport gas used for powder improvement in the ground without running away to the layers, etc. Also, it forms a tubular shield in the excavation process, so it is a columnar pile body in the next stage. The outer surface of the cylindrical body, which is formed by stirring and mixing the powder and soil forming the inside, is surrounded by the tube-shaped shield so that the tube-shaped shield integrally covers the outer surface of the pile body. There is an effect that the outer surface of the cylindrical body is reinforced and the outer surface of the cylindrical body is prevented from being broken or worn, and a smooth outer surface is surely formed to improve the ground as designed.

Further, in the ground improvement device, the injection nozzle for forming the tubular shield is downwardly opened at the end of at least one stage of the stirring blade provided at the lower end of the hollow pipe, so that the rise from the set depth is achieved. Or, in the descending process, the tubular shield is surely formed, and as described above, the escape of the transport gas to the gravel layer or the like is avoided,
Further, there is an excellent effect that a tubular shield can be formed on the outer surface of the cylindrical body at the next stage to reinforce it without causing damage or destruction.

Further, instead of the downward jet nozzle, a slide blade which is displaceable at the tip of the stirring blade is provided, and the slide blade is swung to form a tubular shield and a cylinder as a main body. An excellent effect that a cylindrical body or a tubular shield can be selectively formed by excavating and ejecting a set amount of powder at the time of forming the body is achieved.

[Brief description of drawings]

FIG. 1 of the tubular shield formation of the invention of this application
It is a schematic cross section of an example.

FIG. 2 is a schematic cross-sectional view of another embodiment of the same.

FIG. 3 is an overall schematic partial cross-sectional view of soft ground improvement construction according to the invention of this application.

FIG. 4 is an enlarged partial sectional view of an essential part of one embodiment of the device.

5 is a sectional view taken along line III-IV in FIG.

FIG. 6 is an enlarged partial sectional view of an essential part of another embodiment of the apparatus.

FIG. 7 is an enlarged cross-sectional view of a main part of an apparatus according to another embodiment.

FIG. 8 is a partially enlarged cross-sectional view of another embodiment.

9 is a partial cross-sectional plan view of an essential part of FIG.

FIG. 10 is a schematic plan view of another embodiment of FIG.

FIG. 11 is a partial cross-sectional plan view of still another embodiment of the present invention.

FIG. 12 is a partial cross-sectional schematic diagram of jet agitation based on a conventional technique.

[Explanation of symbols]

 1 Soft Ground 4 Hollow Pipe 5,5 'Stirring Blade 6'Tube Shield 16 Excavation Soil Cylinder 9 Sand Gravel Layer 10 Gas Transport Passage 11,11' Injection Nozzle 100,100 'Powder Injection Stirrer 16 Downward Opening Injection Nozzle 22 Slide blade 27 Actuator 28 Open / close valve 13 Sleeve 17 Cylinder

Claims (12)

[Claims] 1. A hollow pipe is inserted into soft ground, and the powder improving material gas-transported through the hollow pipe is jetted into the ground to mix and agitate with excavated soil, while the transport gas is discharged to the ground. In the powder injection stirring method as described above, a tubular shield made of the powder improving material is formed along the outer surface of the cylindrical body of the excavated soil in the process of excavating the ground with the stirring blade. Powder injection stirring method. 2. The powder jet agitation method according to claim 1, wherein the tubular shield is formed by a descending process of an agitating blade. 3. The powder jet agitation method according to claim 1, wherein the tubular shield is formed at the level of the gravel layer in the ground. 4. The powder jet agitation according to claim 1, wherein the tubular shield is formed in accordance with a mixing and agitation process of the powder improving material with respect to a cylinder of soil. Construction method. 5. The powder jet agitation method according to claim 1, wherein the tubular shield is formed in a process of raising the agitating blade. 6. A hollow pipe to be inserted into soft ground has a gas transport passage for a powder improving material inside, and a stirring blade also serving as an excavator is integrally laterally extended at the base portion thereof. In the powder injection stirring device in which the powder improvement material injection nozzle is provided side by side, the improvement material injection nozzle, which is provided on the stirring blade and is connected to the powder improvement material gas transport passage, has its tip facing downward. A powder jet agitation device characterized in that it is opened in. 7. An injection nozzle, the tip of which is opened downward, is attached to a slide blade which is displaceable in the longitudinal direction at the tip of the stirring blade, according to claim 6. Powder injection stirring device. 8. The powder jet agitator according to claim 7, wherein an actuator for advancing and retracting the slide blade is provided between the slide blade and the hollow pipe. 9. The powder jet agitator according to claim 7, wherein an opening / closing valve is attached to the jet nozzle whose tip is opened downward. 10. A hollow pipe to be inserted into soft ground has a gas transport passage for a powder improving material inside, and at the base thereof, a stirring blade also used for excavation is laterally integrally extended and the stirring blade is also provided. In a powder injection stirring device in which a powder improvement material injection nozzle is provided side by side, an improvement material injection nozzle provided on the stirring blade and connected to a gas transport passage of the improvement material opens its tip downward. The powder injection stirring device is characterized in that it can freely communicate with the gas transport passage of the improving material through a sleeve sliding on the hollow pipe. 11. The powder jet agitator according to claim 10, wherein the sleeve is earth pressure sensitive. 12. The powder jet agitator according to claim 10, wherein the sleeve is of a cylinder type.