JP3703114B2 - Multiple pipe and injection method using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multiplex tube having a built-in packer that prevents a chemical liquid from flowing out from the perforation when the ground is drilled and a chemical solution is injected from the hole to improve the ground.
[0002]
[Prior art]
For tunnel excavation, etc., to improve the soft ground, drill the ground with a small boring machine, insert multiple pipes into the hole, inject chemicals through the pipes, and improve the soft ground with chemicals This has been done more widely than before.
[0003]
At that time, in order to infiltrate the chemical solution over a wide area of the soft ground, the chemical solution is injected at a considerably high pressure, but the packer is expanded so that the chemical solution does not flow up to the outside through the drilling hole (reverse flow). It is made to adhere to a hole wall and the chemical | medical solution which flowed backwards is interrupted | blocked.
[0004]
Most of this type of packer is a rubber which is expanded by compressed air, which is a pressurized gas, in a part of a multiple pipe for injecting a chemical solution as disclosed in JP-A-6-173243 and JP-A-6-170649. When the layer is provided and the ground tube is drilled and the multiple tube is inserted into the hole, the rubber layer that becomes the packer is contracted, and when the chemical solution is injected through the multiple tube, the rubber layer is expanded and sealed. It is configured.
[0005]
[Problems to be solved by the invention]
However, in the case of a conventional packer, a rubber layer (rubber pipe) that expands by compressed air and performs a sealing (or blocking) function as the packer is exposed as it is, and there is nothing that protects the rubber layer. For this reason, there is a problem that the packer portion, which is a rubber layer, is easily damaged by rubbing against the excavation hole wall during insertion of the packer into the perforation, and sometimes it is worn out by friction with the hole wall, making it unusable as a packer.
[0006]
The present invention has been proposed in view of the problems of the prior art as described above, and protects the rubber layer serving as the packer, and when the packer is inserted into the drilling hole, the packer portion which is the rubber layer is used as the drilling hole wall. It is an object of the present invention to provide a multiple tube that can be prevented from being damaged by rubbing and can be used repeatedly over a long period of time.
[0007]
[Means for Solving the Problems]
The multiple pipe of the present invention is inserted into a drilling hole drilled in the ground, and injects a chemical solution for improving the ground, the multiple pipe is expanded by pressurized gas and closely contacts the hole wall. Thus, a rubber layer for constituting a packer for preventing the outflow of the chemical solution is provided, and a bar made of spring steel and extending in the axial direction of the rod is provided on the outer peripheral surface of the rubber layer. The rubber layer is arranged in a manner covering the outer peripheral surface of the rubber layer with an appropriate interval in the direction.
[0008]
When the chemical solution injection method is applied using the multiple pipe of the present invention having the above-described configuration, when the multiple pipe is inserted into the excavation hole when the chemical solution is injected to improve the ground, the rubber layer Since the surface is protected by a bar, it does not come into contact with the borehole wall. Therefore, it is possible to prevent the rubber layer from being rubbed and damaged with the borehole wall.
[0009]
When compressed air is supplied after inserting the multi-pipe containing the packer into the excavation hole, the rubber layer of the packer part expands and its outer peripheral part comes into close contact with the excavation hole wall to seal the chemical solution rising from below or Cut off. At this time, since the bar made of spring steel has elasticity, it is deformed so as to expand (expand) radially outward. Then, due to the elasticity of the spring steel, the bar contracts radially inward when compressed air is excluded, and restores to its original state by itself.
[0010]
As described above, according to the present invention, the rubber layer of the packer portion is not damaged, so that a multiple tube can be used repeatedly. In addition, when the chemical solution is injected, the chemical solution rising from below can be reliably sealed or blocked.
[0011]
Here, it is preferable that the bar is fixed by a portion other than the packer portion of the multiple tube, that is, a reinforcing layer that does not substantially expand by the pressurized gas. In the multiplex tube of the present invention, a bar made of spring steel is exposed to the outside together with the rubber layer in the packer portion.
[0012]
In carrying out the present invention, the bar portion made of spring steel and the packer portion made of a rubber layer may be provided in a plurality of stages at intervals in the axial direction of the multiple tube, or the multiple tube Only one location in the axial direction may be provided. In the case where a plurality of stages are provided, it is preferable that the two packer portions that are continuous in the axial direction of the multiple tube are arranged so that the circumferential positions of the bar members made of spring steel are shifted from each other. By providing a plurality of packer sections and shifting the circumferential position of the bar material of the two packer sections that are continuous in the axial direction of the multiple pipe, the reverse flow of the chemical is blocked by the action of a so-called “labyrinth seal”. Because.
[0013]
The multiple pipe of the present invention is inserted into a drilling hole drilled in the ground, and injects a chemical solution for improving the ground, the multiple pipe is expanded by pressurized gas to the hole wall. A rubber layer for constituting a packer that prevents the outflow of the chemical solution by adhering to the rubber layer is provided. A plurality of belt-shaped protective plates to be covered are arranged at an appropriate interval in the circumferential direction of the multiple tube.
[0014]
Here, the protective plate is rotatable about a rotation axis, and both end portions of the rotation shaft are formed by portions other than the packer portion of the multiple tube, that is, a reinforcing layer that does not substantially expand by the pressurized gas. It is preferably pivotally supported.
[0015]
According to the present invention having such a configuration, since the rubber layer is partially covered with a band-shaped protective plate, the multiple pipes are placed in the excavation hole without contacting the excavation hole wall. Can be inserted. For this reason, the rubber layer of the packer portion is not damaged, and a multiple tube can be used repeatedly.
[0016]
When compressed air is supplied after inserting the multi-pipe containing the packer into the excavation hole, the rubber layer of the packer part expands and its outer peripheral part comes into close contact with the excavation hole wall to seal the chemical solution rising from below or Cut off. At this time, since the protective plate rotates in the direction of expanding outward in the radial direction, the expansion of the packer is not hindered. Since the protective plate is always urged inward by the spring force, if the compressed air is removed, the protective plate contracts radially inward to restore the original state.
[0017]
In carrying out the present invention, it is preferable to provide a plurality of packer portions made of the protective plate and the rubber layer at intervals in the axial direction of the multiple tube. In this case, it is preferable that the two packer portions that are continuous in the axial direction of the multi-pipe are arranged so that the circumferential positions of the protective plates are shifted from each other. There are parts that are not blocked by the packer in the rotating part of the protective plate, but the packer part is provided in multiple stages and the circumferential direction of the protective plate (rotating part) of the two packer parts that are continuous in the axial direction of the multiple tube This is because if the positions are shifted from each other, the backflow of the chemical solution is blocked by the same action as a so-called “labyrinth seal”.
[0018]
The injection method of the present invention using the above-described multiple pipes includes a drilling process for drilling a drill hole in the ground, a multiple pipe insertion process for inserting a multiple pipe into the drilled drill hole, and a packer provided in the multiple pipe. A packer expansion process in which gas is supplied from the ground to inflate the packer and the area above the packer in the excavation hole and the area below the packer are liquid-tightly blocked, and a chemical solution for injecting a chemical solution for improving the ground An injection process, and a packer contraction process in which the gas supplied to the packer is discharged from the packer and contracts the packer when a predetermined time has elapsed after the chemical solution injection. And a rubber layer for constituting a packer that prevents the outflow of the chemical liquid by being in close contact with the hole wall, and the outer peripheral surface of the rubber layer is made of spring steel and extends in the axial direction of the flange The bar to be In a manner that and covering the outer peripheral surface of the rubber layer at a, is characterized in that it is arranged.
[0019]
Alternatively, the injection method of the present invention using the above-described multiple pipe is provided in the multiple pipe, an excavation process of drilling a drill hole in the ground, a multiple pipe insertion process of inserting the multiple pipe into the drilled hole, and the multiple pipe A packer expansion process that inflates the packer by supplying gas from the ground to the packed packer and liquid-tightly blocks the area above the packer and the area below the packer in the excavation hole, and injects chemicals to improve the ground And a packer shrinkage step for shrinking the packer by discharging the gas supplied to the packer when a predetermined time has elapsed after the chemical solution is poured. A rubber layer is provided for constituting a packer that expands by pressurized gas and adheres to the hole wall to prevent the outflow of the chemical solution. The outer peripheral surface of the rubber layer is constantly urged inward by a spring force. Band covering a part of the outer peripheral surface of the rubber layer Protective plate is, is characterized in that it is arranged a plurality at a proper interval in the circumferential direction of the multiple tube.
[0020]
If such an injection method is used, the packer can be repeatedly expanded and contracted many times, which is very convenient.
[0021]
Here, in the injection method of the present invention using the above-described multiple tube, it is preferable to select a gas that is supplied to expand the packer so that the restoration speed at which the expanded packer contracts becomes large. If such a gas is selected, not only the time spent in the packer shrinking process is shortened, but also the speed of following the change over time of the ground increases, so that the chemical injection method for the easily deformed ground This is because there is no possibility of adversely affecting the surroundings when constructing. For example, nitrogen gas (N ₂ gas) is preferable as the “gas that increases the restoring speed at which the expanded packer contracts”.
[0022]
Furthermore, in the present invention, it is preferable that the packer is composed of rubber containing a core material in the connection portion with the multiple tube, and the portion other than the connection portion is composed of rubber containing no core material. .
The packer abuts against the inner peripheral surface of the excavation hole by expanding and blocks the area above the packer and the area below the packer in a liquid-tight manner, so that the packer follows the shape of the inner peripheral surface of the excavation hole. It is necessary to have the above-mentioned flexibility and to have a predetermined strength or more. On the other hand, in order to prevent leakage from the connection portion between the packer and the multi-pipe, the connection portion must be made of a material having sufficient strength and hardly deformed, that is, a material lacking flexibility. . Here, the rubber containing the core material is improved in strength but less flexible. Therefore, if the connecting portion between the packer and the multi-pipe is made of rubber containing a core material, and the packer other than the connecting portion is made of rubber containing no core material, the above-described requirements can be satisfied. It is.
[0023]
The rubber suitable for the packer of the present invention, that is, the rubber having the flexibility to follow the shape of the inner peripheral surface of the excavation hole and having a strength higher than a predetermined level is, for example, , Natural rubber, isoprene rubber, styrene butadiene rubber, butadiene rubber, chloroprene rubber, nitrile butadiene rubber, ethylene propylene rubber, butyl rubber, hypalon, acrylic rubber, urethane rubber, silicone rubber, fluorine rubber, and polysulfide rubber. In particular, natural rubber and urethane rubber are preferable.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
1 to 4 show a first embodiment of the present invention.
The multi-pipe 1 is provided with a rubber layer 2 that is expanded by compressed air that is a pressurized gas and adheres closely to the wall of the excavation hole to prevent the outflow of the chemical liquid. The outer peripheral surface of the rubber layer 2 that becomes the packer portion is made of spring steel. A plurality of rods 3 are provided in the circumferential direction of the tube at an appropriate interval in the axial direction of the tube, and in the illustrated example, 8 are provided. The bar 3 covers the outer peripheral surface of the rubber layer 2 and is fixed by a reinforcing layer 4 (a portion of the multiple tube other than the packer portion) that does not substantially expand by pressurized gas (for example, nitrogen gas: the same applies hereinafter).
[0025]
The rubber layer 2 is made of, for example, urethane rubber. Although not clearly shown, a core material is embedded in the boundary portion with the multiple tube 1 inside the rubber layer 2 serving as a packer portion, but in a portion not corresponding to the boundary portion. The core material is not buried.
[0026]
The reinforcing layer 4 is preferably composed of a synthetic fiber layer and a steel wire layer. In the illustrated example, three portions serving as packers are provided. Further, the bars 3 made of spring steel of adjacent packer portions are arranged so as to be shifted from each other in the circumferential direction of the pipe.
[0027]
In addition, although illustration is abbreviate | omitted, the synthetic resin hose for supplying a chemical | medical solution is further provided in the rubber layer 2 inward.
[0028]
In order to improve the ground by injecting chemicals, the ground is first drilled with a small boring machine. Next, the multiple pipe 1 is inserted into the excavation hole. At that time, since the surface of the rubber layer 2 is protected by the bar 3, the excavation hole wall is not contacted. There is no inconvenience such as the rubber layer 2 being scratched by rubbing against the hole wall. 1 and 2 show a state when the multi-tube 1 is inserted.
[0029]
When the multiple pipe 1 has been installed at a predetermined position of the excavation hole, nitrogen gas (N ₂ gas), which is a pressurized gas, is supplied to expand the rubber layer 2 of the packer portion. At that time, as shown in FIG. 3 and FIG. 4, the bar 3 also spreads outward, but the bar 3 is made of spring steel. Thus, the original state shown in FIGS. 1 and 2 is restored.
[0030]
The rubber layer 2 of the packer part is expanded and brought into close contact with the excavation hole wall to be sealed or cut off. In this case, the chemical solution may leak somewhat from the portion R where the bar 3 shown in FIG. 4 is provided. Therefore, as described above, the bars 3 of the adjacent packer portions are arranged so as to be shifted from each other in the circumferential direction of the pipe. Thereby, the leakage of the chemical solution from the R portion is completely prevented (blocked).
[0031]
After acting the packer in the above-described manner, the chemical solution is injected through the multiple pipe 1 to improve the ground. When the injection of the chemical solution through the excavation hole is completed, the pressurized gas is discharged from the packer portion, the rubber layer 2 is contracted, and the multiple pipe 1 is pulled out from the excavation hole to be supplied for the chemical solution through the next excavation hole.
[0032]
In addition, although the packer part provided with the bar material may be only one place, if a plurality of places (three places) are provided as shown in the figure, sealing or blocking is more reliable.
[0033]
5 to 8 show a second embodiment of the present invention, in which a multiple tube 10 is provided with a rubber layer 11 that is expanded by compressed air that is a pressurized gas and adheres closely to a drilling hole wall to prevent outflow of a chemical solution. A plurality of strip-shaped protective plates 12 that are always inwardly biased by a spring force and cover a part of the rubber layer on the outer peripheral surface of the rubber layer 11 serving as a packer portion with a gap in the circumferential direction of the tube, In the illustrated example, four sheets are provided. The protective plate 12 is made of a metal plate and is attached to the pipe by a bar 13. A synthetic resin hose 14 through which a chemical solution is passed is provided in the inner layer of the rubber layer.
[0034]
5 and 6 show the state of the protection plate 12 when the multi-pipe 10 is inserted into the excavation hole. The rubber layer 11 is protected by the protection plate 12 and the surface of the rubber layer 11 is not in contact with the excavation hole wall. The rubber layer 11 is not damaged by rubbing against the hole wall.
[0035]
By supplying the pressurized gas, the rubber layer 11 of the packer portion expands as shown in FIGS. 7 and 8, and the rubber layer 11 is in close contact with the excavation hole wall and sealed or blocked. In the case of this embodiment as well, the chemical solution may leak somewhat from the mounting portion R of the protective plate 12, so that the protective plates 12 of the adjacent packers are shifted from each other in the circumferential direction of the tube. Thereby, the leakage of the chemical solution from the R portion is completely prevented.
[0036]
In addition, although the packer part which provided the protective plate may be only one place, if it provides in multiple places (three places) like illustration, a seal | sticker or interruption | blocking will become more reliable.
[0037]
【The invention's effect】
According to the multiple pipe and injection method of the present invention, the surface of the rubber layer of the packer part is protected by a bar or plate material. Therefore, when the chemical solution is injected to improve the ground, the multiple pipe is inserted into the excavation hole. In doing so, the rubber layer is not rubbed and damaged by the wall of the excavation hole, and the multi-pipe can be used in good condition repeatedly for a long time.
[0038]
Also, even if a bar or plate material is provided on the surface of the rubber layer of the packer part, the bar or plate material acts as a spring. It expands and closes well with the borehole wall to seal or shut off. At that time, the bar or plate spreads outward, but if the pressurized gas is removed, it returns to its original state by itself and can be used as it is.
[0039]
Further, by providing a plurality of packer portions provided with bar materials or plate materials and arranging the bar materials or plate materials of adjacent packer portions shifted from each other in the circumferential direction of the pipe, more reliable sealing or blocking can be performed. it can.
[0040]
Furthermore, in the injection method of the present invention, if a gas that increases the restoration speed at which the expanded packer contracts is used, not only the time spent on the packer contracting process is shortened, but also the ground changes over time. Since the following speed increases, there is no possibility of adversely affecting the surroundings when the chemical injection method is applied to the easily deformable ground, which is preferable.
[Brief description of the drawings]
FIG. 1 is a front view showing a state in which a packer of a multi-pipe is contracted in the first embodiment.
FIG. 2 is an enlarged cross-sectional view of the packer portion of FIG.
3 is a front view showing an expanded state of a packer in the multiple pipe of FIG. 1; FIG.
4 is an enlarged cross-sectional view of the packer portion of FIG. 3;
FIG. 5 is a front view showing a state where the packer is contracted in the second embodiment.
6 is an enlarged cross-sectional view of the packer portion of FIG.
7 is a front view showing an expanded state of the packer in the multiple pipe of FIG. 5;
8 is an enlarged cross-sectional view of the packer portion of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Packer built-in multiple tube 2 ... Rubber layer 3 ... Bar material 4 made of spring steel ... Reinforcement layer 10 ... Packer built-in multiple tube 11 ... Rubber layer 12 ... Protection plate 13 ... Bar 14 ... Synthetic resin hose

Claims (9)

In a multiplex tube that is inserted into an excavation hole drilled in the ground and injects a chemical solution for improving the ground, the multiplex tube expands due to pressurized gas and adheres to the hole wall so that the chemical solution flows out. A rubber layer for constituting a packer to be prevented is provided, and on the outer peripheral surface of the rubber layer, rods made of spring steel and extending in the axial direction of the flange are spaced at an appropriate interval in the circumferential direction of the tube. And the multiple pipe | tube arrange | positioned in the aspect which coat | covers the outer peripheral surface of the said rubber layer. The multiplex pipe according to claim 1, wherein a plurality of the packers formed of the spring steel and the rubber layer are provided at intervals in the axial direction of the multiplex pipe. The multiplex tube of claim 2, wherein two packer portions that are continuous in the axial direction of the multiplex tube are arranged so that circumferential positions of the bar members made of spring steel are shifted from each other. In a multiplex tube that is inserted into an excavation hole drilled in the ground and injects a chemical solution for improving the ground, the multiplex tube expands due to pressurized gas and adheres to the hole wall so that the chemical solution flows out. It is provided with a rubber layer for constituting a packer to prevent, and on the outer peripheral surface of the rubber layer, a belt-shaped protective plate that is always urged inward by a spring force to cover a part of the outer peripheral surface of the rubber layer, A multiple tube, wherein a plurality of tubes are arranged at an appropriate interval in the circumferential direction of the multiple tube. The multiple tube according to claim 4, wherein a plurality of packer portions including the protective plate and the rubber layer are provided at intervals in the axial direction of the multiple tube. The multiplex tube according to claim 5, wherein the two packer portions that are continuous in the axial direction of the multiplex tube are arranged so that the circumferential positions of the protective plates are shifted from each other. Excavation process for drilling holes in the ground, multiple pipe insertion process for inserting multiple pipes into the drilled holes, and gas supply from the ground to the packer provided in the multiple pipes to expand the packer A packer expansion process for liquid-tightly blocking the area above the packer and the area below the packer of the excavation hole, a chemical injection process for injecting a chemical to improve the ground, and a predetermined time after the chemical injection A packer contraction step for discharging the gas supplied to the packer from the packer and contracting the packer, and the multiple pipe expands due to the pressurized gas and adheres to the hole wall so that the chemical solution flows out. A rubber layer for constituting a packer for preventing the rubber is provided, and on the outer circumferential surface of the rubber layer, a bar made of spring steel and extending in the axial direction of the pipe has an appropriate interval in the circumferential direction of the pipe. Cover the outer peripheral surface of the rubber layer apart By way, the injection method using the multi-tube of any one of claims 1-3, characterized in that it is arranged. Excavation process for drilling holes in the ground, multiple pipe insertion process for inserting multiple pipes into the drilled holes, and expanding the packer by supplying gas from the ground to the packers provided in the multiple pipes A packer expansion process for liquid-tightly blocking the area above the packer and the area below the packer of the excavation hole, a chemical injection process for injecting a chemical to improve the ground, and a predetermined time after the chemical injection A packer contraction step for exhausting the gas supplied to the packer from the packer and contracting the packer, and the multiple pipe expands by the pressurized gas and adheres to the hole wall, thereby allowing the chemical solution to flow out. A rubber layer for constituting a packer for preventing the rubber layer is provided, and on the outer peripheral surface of the rubber layer, there is a belt-like protective plate that is always urged inward by a spring force to cover a part of the outer peripheral surface of the rubber layer. Multiple pipes are spaced at appropriate intervals in the circumferential direction of the multiple tubes. Injection method using the multi-tube of any one of claims 4-6, characterized in that it is single-arranged. The said packer is comprised with the rubber | gum in which the core material is contained in the connection part with a multiple tube, and places other than this connection part are comprised with the rubber | gum which does not contain the core material. The injection method of item 1.

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