JP3964232B2 - Powder transport system for powder jet agitator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The disclosed technology is based on a storage tank for cement and other powder improvement materials used for ground improvement in DJM (powder injection agitation method), which has been used for many ground improvement works recently. The present invention belongs to the field of technology for stably and continuously pneumatically transporting into a casing pipe that is inserted into the ground through a hole.
[0002]
[Prior art]
As is well known, in the ground improvement work, various construction techniques such as chemical injection have been developed and adopted for a long time, but the seed chemical injection works because the ground water in the ground reacts with the injected chemical and groundwater contamination, etc. The possibility of causing pollution problems is becoming more and more recent, and there are also old technologies such as so-called sand drain and paper drain, but these technologies have poor operating efficiency and can be used instead. As a technology, the powder improvement material such as cement has recently been transported into the surrounding ground through a hole formed in the ground, and mixed with the surrounding soil. A new DJM (powder jet agitation construction method) technology has been developed to improve the ground by solidifying and solidifying, and gradually there are effects to be seen, and some results have been seen recently.
[0003]
Thus, the DJM (powder jet agitation construction method) technology also forms holes in the ground as the amount of construction increases, and the piles created in the ground by pneumatic transportation of powder improving materials such as cement The technology that continuously forms a predetermined ground improvement work is expected to reduce the cost of recent construction, increase efficiency, introduce new technology, etc., so that the diameter of the built pile will exceed the 1300mm of the large diameter recently The large-diameter ones have been performed at medium and large depths.
[0004]
Thus, when forming a conventional pile with a diameter of about 1000 mm in forming the pile with the large diameter drilling hole and the adjacent pile with the drilling hole in the ground, In the conventional technique, the powder such as cement supplied to the casing pipe in the drilling hole has a diameter exceeding 1300 mm, for example, a small amount such as 3.5 t or a medium amount supplied. When a large-diameter constructed pile is formed, it is necessary to supply a large amount of cement that exceeds 6 to 8 tons. Therefore, in the new technology, as much as possible supply of powder improving materials such as cement is required during construction, resulting in uneven supply of the improving material, But as designed There was a problem that no longer Ka.
[0005]
The technology of the conventional mode is in a plant on the ground, and a powder improving material such as cement is established as a method of press-fitting into a ground from a batch type two-chamber tank through a casing pipe in the drilling hole. Therefore, it is required to be a continuous type, and stable supply and replenishment during construction is required as a property of construction. Therefore, an improvement material for powder such as cement from the two-chamber tank. The replenishment supply in the middle does not smoothly switch the improvement material to the continuous single passage connected to the chamber and the casing pipe, so that the switching requires time interruption, resulting in construction efficiency. The improvement of the ground through the large diameter construction piles has the disadvantage that the ground improvement becomes unstable and the ground improvement becomes unstable and cannot be performed as designed. Construction work there is drawback that smooth hard done was also disadvantage consequently leads to high cost.
[0006]
[Problems to be solved by the invention]
The object of the invention of this application is to provide a powder improving material in the middle of construction of a continuous batch type tank having two chambers in ground improvement work through a large-diameter constructed pile which has recently been demanded based on the above-mentioned prior art. As a technical issue that should solve the problem of reduced construction efficiency due to loss of time interruption at the time of switching at the time of replenishment, negative points of construction accuracy and high cost,
In view of the instability and interruption of the supply of powder improvement material required for large-capacity large-diameter construction piles, multiple tanks are installed side by side, and the powder improvement material is intermediately placed in each tank. By switching the tanks, switching and replenishment of the casing pipe in the drilling holes formed in the ground of the powder improvement material in the press-fitting and transport to the casing pipe is stabilized, and the detection method using the load cell continuously Detects tank weight loss and switches automatically so that continuous replenishment can be performed without interruption.Powder supply of powder-improving material into the casing pipe can be smoothly performed to press-fit the ground as designed. Excellent DJM (powder jet agitation) that improves construction efficiency, is safe and cheap, and benefits the field of civil engineering applications in the construction industry Is to St. provide powder transport system Engineering).
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the configuration of the invention of this application, which is based on the above-mentioned object and is summarized in the above-mentioned claims,
In a transportation system using air to the ground for improved powder used for powder injection agitation, the powder is supplied to and stored in a plurality of tanks, and air is pressed into the tank and mixed with the improved powder by the air. First, the improved powder from the alternate tanks is supplied to the ground around the drilling hole through the junction valve provided in the passage from the adjacent tank via the feeder discharge valve. As the backbone of
Thus, each tank is automatically controlled by the load cell type weight detection system for each of the tanks so that the improved powder transportation is automatically controlled, and the alternating powder transportation is continuously performed at minute intervals without interruption. In this case, the minute interval is set to be several seconds or less, and the discharge valves of the adjacent tanks at the time of the switching are instantaneously connected to each other. The opening operation may be performed continuously, or the air blowing air valve of the tank may be operated during the opening operation of the discharge valve port and the merging valve. The technical means is also provided in which the confluence valve of the adjacent tank at the time of switching is operated so as to overlap in a short time.
[0008]
[Action]
Thus, in the above-described configuration, a hole is formed in the ground via the casing pipe, and the powder improvement material is supplied and stored in a plurality of tanks disposed on the ground with respect to the casing pipe. The weight loss due to pneumatic transportation to the casing pipe through the load cell is measured with respect to the frame of the tank so as not to be interrupted at the time of switching, and a powder improving material such as cement is supplied from the silo to the tanks 71 and 72 by the conveyor 79. Then, compressed air is supplied to the tanks 71 and 72 through the compressor 92, and the tanks 71 and 72 are initially pressurized.
The confluence valve 90 (91) in the passage of the improving agent of one tank 71 (72) initially pressurized is opened, and at the same time, the air blow valve 84 (85) is opened, and compressed air is supplied through the compressor 72 to empty the air. After spraying and securing a passage for supplying the powder improving agent to the surrounding ground 2 of the drilling hole 3, the air blowing valve 84 (85) is closed, the discharge valve 87 ′ (88 ′) is opened, Press the improver into the ground.
With respect to the frame of the tank 71 (72), the weight loss of the improving agent in the tank 71 (72) is measured via the load cell 100, and if it decreases from the set point via the sequence, the discharge will occur. Close the outlet valve 87 ′ (88 ′), open the air blow valve 84 (85), and simultaneously open the air blow valve 84 (85) of the adjacent pressurized tank 71 (72) adjacent to each other. Both adjacent tanks open the air blowing valve 84 (85).
The merging valves 89 and 85 are opened to the passage of the adjacent tank 72 at the same timing through the sequence, and the adjacent tank 72 at the same timing is closed to the blow-off valves 84 and 85 and the discharge port valve 87. , 88 are opened, and the press-fitting of the improving agent into the ground 2 surrounding the hole 3 is continued.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The following is a description of embodiments of the invention of this application as embodiments of the present invention with reference to the drawings.
[0010]
The illustrated embodiment is an embodiment using DJM (powder jet agitation construction). In the embodiment shown in FIG. 1, 1 indicates a plant for construction, and a predetermined portion of a predetermined improved ground 2 is drilled. 3 is formed by excavation with a predetermined excavator 6 by a casing pipe 5 integrally having a stirring blade 4 at its tip, and each powder storage tank 71, 72 is connected to a passage 75 via feeders 73, 74. , 76 through a passage 77 that joins together, the cement of powder improving material is mixed with air into the casing pipe 5 via the drive device 6 in a swivel joint manner, and transported to the base of the stirring blade 4 of the casing pipe 5. The nozzle 15 is press-fitted into the soil of the ground 2 around the drilling hole 3 from the back into the rotating region of the stirring blade 4, and the soil and cement are mixed and stirred to solidify and solidify over time. It is to use a DJM method conventional manner which is to perform ground improvement through the formation of Construction pile.
[0011]
Thus, on the upper portions of the tanks 72, 71, the feeding conveyors 79 branchingly connected from the vertical feeding conveyor 78 from the silo 70 ′ to the tanks 71, 72 at the lower end of the tip are connected to the branch supply valves 80, 81. The tanks 71 and 72 are provided with open / close-type electric charging valves 82 and 83, and exhaust valves 84 and 85, respectively. Further, known feeders (bromart) 73 and 74 are interposed under the tanks 71 and 72, and the feeders (bromart) 73 and 74 have discharge ports 87 having valves 87 'and 88'. , 88 are provided, and at the joining portions of the adjacent passages 75, 76, merging valves 90, 91 are respectively provided to join the fed powders to join the casing pipe 5. It is connected to the passage 77.
[0012]
Thus, for each tank 71, 72, there is a compressor 92 (a plurality of units may be provided so as to be individually disposed in each tank 71, 72), and the upper portion of the hole 3 is hermetically sealed. The hood 97 is provided, and the powder to be transported by being mixed with the transported air together with the improvement material as the powder to be replenished in the air transport type, which is selectively switched from the tanks 71 and 72 and supplied. The powder is separated from the dust collector 98 by the back filter 99 so that only normal air is diffused into the atmosphere.
[0013]
A predetermined sequencer is provided in the control device 96, and the exhaust valves 84, 85, the discharge ports 87, 88, the discharge port valves 87 ', 88', the merging valves 90, 91, and the feeder are provided according to a predetermined program. The discharge amounts of the bromates 73 and 74 and the merging valves 90 and 91 are controlled in a predetermined and stable manner according to the time chart.
[0014]
By the operation of the sequencer, the operation start and stop timing of the tanks 71 and 72 are controlled according to a predetermined time chart, and the time of interruption at the time of switching is time for feeding the powder of the cement feeders 73 and 74. Is within a few seconds, for example, about 8 seconds, and the casing pipe 5 passes through the material hoses 75, 76, 77 in the same passage for powder switching without interruption for a long time of 8 seconds or more. It is pumped to the inner nozzle 15.
[0015]
Then, the interruption or instability of the powder supply due to the switching of the two-chamber tank in the conventional mode is surely eliminated.
[0016]
Further, the embodiment shown in FIG. 1 has two tanks 71 and 72, but the embodiment can be applied to three or more tanks 71, 72... As shown in FIG. Of course.
[0017]
In this embodiment, merging valves 90, 91 '' are provided in the passages 75, 76 ... from the tanks 71, 72 ... so that the transport air pressure from the compressor 92 is sequentially applied in a predetermined manner via the control device 96. Of course, it will be done.
[0018]
In this embodiment, it is needless to say that a predetermined number of a plurality of compressors 92 for the tanks 71 and 72 are provided so that compressed air can be selectively supplied to the tanks 71 and 72.
[0019]
When compressed air is supplied from the compressor 92 to the tanks 71 and 72, the air blown air can be exhausted from the exhaust valves 84 and 85 within the time of operation within several seconds according to the time chart. At the time of the switching, the selective switching operation of the discharge port valves 87 ′ and 88 ′ and the merging valves 90 and 91 ″ ″ is performed in accordance with a control signal from the control device 96 by a sequencer. The timing of the pneumatic transportation of the powder in the tanks 71 and 72 is detected and controlled by the load cells 100 interposed in the tanks 71 and 72 with respect to the frame. This is used for controlling the sequencer of the device 96.
[0020]
Thus, the powder supplied to the nozzle 15 of the casing pipe 5 and supplied by air transportation is lifted from the hood 97 via the spill of the casing pipe 5 to separate the transportation air and the powder and collect the dust. It is possible to remove the dust by the back filter 99 in the vessel 78 and remove the dust in a non-polluting manner so that only normal air is dissipated into the atmosphere. Is exactly the same.
[0021]
Of course, the removal of air after transportation can, of course, be replaced with a spill method for the hood 97.
[0022]
Of course, the embodiments of the invention of this application are not limited to the above-described embodiments. For example, other techniques may be used.
[0023]
【The invention's effect】
As described above, according to the invention of this application, in a construction method that is basically used in a new ground improvement work such as DJM (powder jet agitation method), the formed pile formed in the drilling hole has a diameter of 1000 mm or the like. Although a method of becoming a large-diameter thing exceeding 1300 mm from the one has recently been desired, it is also designed in practice, but forms a large-diameter formed pile In some cases, powder must be replenished in the middle of construction using the air transportation method, which is replenished in the middle of construction. Although the amount of the powder is potentially interrupted or the particle size component becomes unstable, according to the invention of this application, it can be continuously and stably performed in a batch system, Continuous low powder Replenishment is guaranteed, construction efficiency is stable, construction is performed as designed, and as a result, the reliability of the ground improvement is improved and the initial cost can be stabilized in terms of cost. The effect is played.
[0024]
In particular, powder that is pneumatically transported from one tank to another by switching multiple tanks can be switched in a very short time of a few seconds or less during the switching operation, and can be switched in a very short time of several seconds. Although the amount of powder to be pneumatically transported is large, a continuous batch system is guaranteed. As a result, the powder to be pneumatically transported is stabilized, and the ground improvement work through the stable pile is performed as designed, There is a merit that the reliability of the ground improvement is remarkably increased and the cost is easily increased.
[0025]
That is, even though the conventionally known powder by batch-type continuous pneumatic transportation supply exists as a powder jet agitation method (DJM) method, a plurality of tanks can be used while using the known technology. The stored powder can be replenished without being interrupted continuously, and the operation time for switching between the multiple tanks can be shortened, improving work efficiency and work efficiency. An excellent effect is achieved.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of an embodiment of the invention of this application.
FIG. 2 is a schematic explanatory diagram of another embodiment.
[Explanation of symbols]
2 Ground 22 Compressor 71, 72 Tank 73, 74 Feeder (bromate)
75, 76 Passage 82, 83 Input valve 84, 85 Exhaust valve 87, 88 Discharge valve 90, 91 Junction valve 100 Load cell

Claims (3)

In the transportation system by air to the ground of the improved powder used for powder jet agitator,
A plurality of tanks (71) (72) for storing the improved powder ;
A compressor (92) for supplying compressed air for powder transportation to the plurality of tanks (71) (72) ;
Discharge port valves for controlling the discharge of the improved powder from each of the tanks (71) (72) provided at the powder discharge ports (87), (88) of the plurality of tanks (71), (72) , respectively. (87 ') (88') ,
A plurality of passages (75), (76) individually connected to the discharge port valves (87 ') (88') on the upstream side and adapted to join on the downstream side ;
A merging valve (90) (91) provided in each of the plurality of passages (75) (76) before the merging point ;
The hose (77) for feeding the improved powder to a predetermined portion of the improved ground, and connected to the plurality of passages (75), (76) joined together ,
A powder transport system for a powder jet agitator characterized by comprising: The plurality of tanks (71) (72) Each feeder for feeding improved powder (73) (74) Have
The plurality of passages (75) (76) The feeder (73) (74) Outlet valve (87 ') (88') Each connected to
The powder transportation system according to claim 1, wherein: The plurality of tanks (71) (72) Each has a load cell type measuring device for measuring the amount of powder remaining in the tank,
Depending on the amount of powder in the tank, the discharge valve (87 ') (88') And the junction valve (90) (91) Each of these is opened and closed at a predetermined timing
The powder transportation system according to claim 1, wherein:

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