JP5347521B2 - Ground improvement device and ground improvement method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a soil improving method and a soil improving apparatus capable of reliably recovering packers and a chemical feed pipe which are inserted into an excavated hole. <P>SOLUTION: This soil improving method comprises a step of inserting the soil improving apparatus 1 into the excavated hole 2, a step of expanding the second packer 7, a step of injecting a chemical 3 into the feed pipe 4 and injecting the chemical into an earth E through the injection holes of the feed pipe 4, a step of expanding the first packer 6 with the second packer 7 expanded, a step of contracting the second packer 7, a step of injecting washing water into the feed pipe 4 and injecting the washing water into the excavated hole 2 through the injection holes 4a to wash out the insides of the feed pipe 4 and the excavated hole 2, and a step of contracting the first packer 6 and taking out the soil improving apparatus 1 from the inside of the excavated hole 2 after the chemical 3 injected into the earth E has been hardened. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a ground improvement method and a ground improvement device, and in particular, a ground improvement device that performs ground improvement by injecting a chemical material for ground improvement using a packer into an excavation hole formed in a natural ground. And ground improvement method.

  Conventionally, a ground improvement device equipped with a packer for sealing at the hole mouth side is inserted into a drilling hole formed in a natural ground and installed at a predetermined depth. A method of improving the ground by injecting chemicals to improve the ground is being implemented. However, in this method of injecting the chemical material, the chemical material injected into the drill hole on the bottom side of the packer leaks into the drill hole on the hole side of the packer through the crack and hardens. In some cases, the hardened medicine may be in the way, making it impossible to lift the packer to the ground.

Therefore, for example, in Patent Document 1, while injecting a chemical into a drilling hole closer to the hole bottom than the packer, the cleaning water is always injected into the drilling hole closer to the hole than the packer. A method of removing chemicals leaking into the side excavation hole is disclosed.
JP-A-4-76109

  However, in the method described in Patent Document 1, the inside of the feed pipe for feeding the chemical and the inside of the excavation hole communicate with each other through the injection hole opened in the feed pipe. If the chemical remaining in the feed pipe without being integrated with the chemical injected into the excavation hole is hardened, there is a problem that the packer and the feed pipe cannot be collected.

  Therefore, the present invention has been made in view of the above-described conventional problems, and the ground improvement that can reliably collect the packer and the chemical material feeding pipe inserted into the excavation hole for ground improvement. It aims at providing a construction method and a ground improvement device.

In order to achieve the above object, the present invention is a ground improvement device that is inserted into a drilling hole formed in a natural ground and injects a chemical material for ground improvement into the natural ground from the drilling hole. An injection hole is provided in the side surface in the vicinity of the distal end portion, and is connected to the distal end side of the supply pipe for feeding the drug material, and to the distal end side of the injection hole of the supply pipe. A first packer that can be expanded and contracted, a second packer that is provided on a proximal end side with respect to the injection hole of the supply pipe, and that can be expanded and contracted by a working fluid pressure, and the drug material in the supply pipe Chemical material supply means for supplying, working fluid supply means for supplying working fluid for expanding and contracting each of the first packer and the second packer, and cleaning water supply for supplying cleaning water into the feed pipe and means, said feed pipe, first packer of the more injection holes also leading end side Characterized in that and a portion attached and with the portion from the base end portion can be divided.

  According to the ground improvement device of the present invention, since the first and second packers are provided, the first packer can be inflated while holding the pressurized state of the chemical material with the second packer. it can. Therefore, the pressure in the injection hole can be released in a state where the chemical is pressurized against the natural ground.

Moreover, since the cleaning water supply means for supplying the cleaning water into the feeding pipe is provided, the second packer is contracted after the first packer is expanded, and the cleaning water is injected into the feeding pipe. The medicine material in the feed pipe and the medicine material closer to the hole than the first packer in the excavation hole can be removed. Therefore, there is no chemical material around the feed pipe and the second packer, and the chemical material remaining in the feed pipe and the chemical material injected into the drilling hole are integrated and hardened as in the past. Since there is nothing to do, the ground improvement device can be recovered. Thereby, the ground improvement device can be reused.
Further, the ground improvement device is capable of dividing the portion where the first packer on the tip side of the injection hole is attached and the portion on the base end side from the portion so that the tip portion is hardened. Even when it is no longer peeled off from the medicine, the feeding pipe and the second packer can be recovered by separating the tip side from the first packer.

In this invention, it is good also as providing the projection part of the shape which is connected to the front-end | tip part of said 1st packer, and becomes a taper toward the front-end | tip direction.
This makes it possible to release the pressure acting on the bottom surface of the first packer to the side even when high-pressure groundwater is springing from the borehole. It can be inserted into the borehole.

The present invention is provided with an injection hole that opens in the side surface near the tip, and is connected to the tip side of the feed pipe for feeding the chemical material for ground improvement, more than the injection hole of the feed pipe, A first packer that can be expanded and contracted by working fluid pressure, a second packer that is provided at a proximal end side with respect to the injection hole of the feeding pipe, and that can be expanded and contracted by working fluid pressure, and the inside of the feeding pipe A chemical material supply means for supplying the chemical material, a working fluid supply means for supplying a working fluid for expanding and contracting each of the first packer and the second packer, and supplying cleaning water into the supply pipe In the ground improvement method for improving the ground using the ground improvement device comprising the cleaning water supply means, the step of inserting the ground improvement device into the excavation hole formed in the ground, and the second packer Inflating and closely contacting the inner peripheral surface of the excavation hole; A step of injecting a chemical material into the excavation hole through the injection hole from the recording pipe and injecting the chemical material into a natural ground; and the second packer closely contacting the inner peripheral surface of the excavation hole In a state where the first packer is expanded and brought into close contact with the inner peripheral surface of the excavation hole, the second packer is contracted, and the excavation from the feed pipe through the injection hole Injecting cleaning water into the hole, cleaning the inside of the feed pipe and the inside of the excavation hole, the step of shrinking the first packer after the chemical material injected into the natural ground, and the ground improvement And a step of removing the device from the borehole.

  According to the ground improvement method of the present invention, a ground improvement device including a feeding pipe for feeding a chemical material into a drilling hole and first and second packers is inserted into a drilling hole formed in a natural ground. A step of inflating the second packer, and a step of injecting the chemical material into the supply pipe and injecting it into the natural mountain, so that the chemical material is injected into the natural mountain around the excavation hole The strength of natural ground can be increased. Furthermore, since the chemical material can be pressed and held in the excavation hole at a high pressure, the chemical material can be injected into a water channel having a spring pressure. Therefore, it is effective for stopping spring water.

  According to the present invention, it is possible to reliably improve the ground even in a mountain having a large amount of spring water or a high spring pressure. Moreover, even if it is allowed to stand until the strength of the chemical material is expressed, the ground improvement device can be reliably recovered.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a view showing a state in which a ground improvement device 1 according to an embodiment of the present invention is installed in an excavation hole 2 provided near a face of a tunnel. Moreover, FIG. 2 is the figure which expanded the excavation hole 2 vicinity of FIG. Furthermore, FIG.3 and FIG.4 is the perspective view and sectional drawing which show the ground improvement apparatus 1 which concerns on embodiment of this invention.

  As shown in FIGS. 1 to 4, the ground improvement device 1 includes a feed pipe 4 that feeds a chemical 3 for improving the ground into the excavation hole 2, and an injection that opens on the side of the feed pipe 4. A first packer 6 connected to the hole bottom 2a side of the hole 4a, a second packer 7 connected to the hole port 2b side of the injection hole 4a opening on the side surface of the feed pipe 4, and The chemical material supply means 8 for supplying the chemical material 3 into the tube 4, the working fluid supply means 9 for supplying the working fluid to the first packer 6 and the second packer 7, and the protrusion 11 connected to the tip And a cleaning water supply means 10 for supplying cleaning water into the feed pipe 4.

  A plurality of injection holes 4 a are opened at the tip of the feed pipe 4. The chemical 3 that is press-fitted into the feed pipe 4 flows into the excavation hole 2 through the injection hole 4a, and is then injected into the crack 12 and the water channel 13 in the natural ground E. This chemical material 3 hardens in the crack 12 and the water channel 13 and reinforces the natural ground E.

  In the present embodiment, cement milk is used as the chemical material 3, but the present invention is not limited to this. For example, foamable urethane may be used.

  The 1st packer 6 and the 2nd packer 7 are comprised from the cylinder and the ring-shaped rubber body attached to the outer peripheral surface of this cylinder. The rubber body is made of an elastic rubber sheet and can be expanded and contracted by a working fluid pressure. In the present embodiment, nitrogen gas is used as the working fluid, but the present invention is not limited to this. For example, water may be used.

The first packer 6 and the feed pipe 4 are detachably connected. In this embodiment,
The first packer 6 and the protrusion 11 can be separated at the tip end portion of the feed pipe 4.

  The working fluid supply means 9 for supplying the working fluid to the first packer 6 and the second packer 7 includes a nitrogen gas cylinder, and a tube for feeding nitrogen gas to the first packer 6 and the second packer 7. The pressure gauges for measuring the pressure in the packers 6 and 7 are installed in the tunnel.

  The protrusion 11 attached to the tip of the ground improvement device 1 has a conical shape that tapers toward the hole bottom 2a side.

  The cleaning water supply means 10 includes a water storage tank for storing water, a mixing device for mixing the water and bentonite to produce cleaning water, a pump for pumping the cleaning water to the feed pipe 4, and a pump And a hose connecting the feed pipe 4 and installed in the tunnel. The cleaning water supply means 10 and the chemical material supply means 8 are connected to the supply pipe 4 so that the chemical material 3 to be supplied or the cleaning water can be switched.

  In the present embodiment, a mixture of water and bentonite is used as the cleaning water, but the present invention is not limited to this, and only water may be used.

Next, a method for improving the ground using the ground improvement device 1 configured as described above will be described in accordance with a construction procedure.
5-9 is the figure which showed the procedure which improves the ground using the ground improvement apparatus 1 which concerns on this embodiment.

  First, as shown in FIG. 2 described above, the ground improvement device 1 is inserted into the excavation hole 2 and installed at a predetermined position. At this time, even when high-pressure groundwater is springing from the inside of the excavation hole 2, the protrusion 11 is provided at the tip of the ground improvement device 1, thereby acting on the tip of the ground improvement device 1. Since the spring water pressure can be released to the side, the ground improvement device 1 can be easily inserted into the excavation hole 2.

  Next, as shown in FIG. 5, the nitrogen gas in the nitrogen gas cylinder is supplied to the second packer 7 through the tube, and the second packer 7 is expanded. Due to the supply pressure of nitrogen gas, the rubber body of the second packer 7 expands in the radial direction and comes into close contact with the inner peripheral surface 2 c of the excavation hole 2. The expansion pressure of the second packer 7 is measured with a pressure gauge, and the supply of nitrogen gas is stopped when a predetermined pressure is reached.

  Next, as shown in FIG. 6, the chemical | medical material 3 is supplied in the feed pipe 4 with a predetermined pressure with a pump. The supplied chemical material 3 passes through the feed pipe 4 and is press-fitted into the excavation hole 2 through the injection hole 4a. And the chemical | medical material 3 press-fitted in the excavation hole 2 with high pressure is inject | poured into the crack 12 and the water path 13 which were formed in the natural ground E. At this time, since the expansion pressure of the second packer 7 is adjusted to be larger than the injection pressure of the drug material 3, the drug material 3 in the excavation hole 2 leaks from the periphery of the second packer 7. do not do.

  When a predetermined amount or more of the drug material 3 determined in advance by design or the like is injected, the second packer 7 is kept in close contact with the inner peripheral surface 2c of the excavation hole 2 as shown in FIG. One packer 6 is inflated. The first packer 6 is expanded by supplying nitrogen gas in a nitrogen gas cylinder to the first packer 6 through a tube in the same manner as when the second packer 7 is expanded. The rubber body of the first packer 6 expands in the radial direction by the supply pressure and comes into close contact with the inner peripheral surface 2c of the excavation hole 2, and when the expansion pressure of the first packer 6 reaches a predetermined pressure, supply of nitrogen gas is performed. Stop.

  Thereafter, the expansion pressure of the second packer 7 is released, the rubber body is contracted, and separated from the inner peripheral surface 2 c of the excavation hole 2. The 1st packer 6 maintains the state expanded until the chemical | medical material 3 hardened | cured to such an extent that it was not poured by the spring water.

  Next, as shown in FIG. 8, simultaneously with releasing the expansion pressure of the second packer 7, cleaning water in which water and bentonite are mixed is supplied to the feed pipe 4 by a pump. The supplied cleaning water passes through the feed pipe 4 and flows into the excavation hole 2 through the injection hole 4 a, and further, a gap between the inner peripheral surface 2 c of the excavation hole 2 and the feed pipe 4. 16 is discharged out of the excavation hole 2. Since the cleaning water removes the chemical 3 existing in the feed pipe 4 and the gap 16, the chemical 3 is contained in the feed pipe 4, on the outer peripheral surface of the second packer 7 and in the gap 16. There is no curing. Therefore, the chemical | medical material 3 hardened in the natural ground E and the injection hole 4a part can be cut off.

  When the curing time of the chemical determined in advance by design or the like has elapsed, as shown in FIG. 9, the expansion pressure of the first packer 6 is released, the rubber body is contracted, and the inner peripheral surface 2c of the excavation hole 2 is released. Release. Then, the ground improvement device 1 is pulled out from the inside of the excavation hole 2. At that time, when the curing of the chemical solution proceeds more than expected and the chemical solution and the first packer 6 or the protrusion 11 are firmly attached, the connection with the first packer 6 is disconnected and the feeding is performed. The tube 4 and the second packer 7 can be recovered.

  According to the ground improvement method using the ground improvement device 1 configured as described above, the ground improvement device 1 is inserted into the excavation hole 2 and the chemical material 3 is injected into the ground E using the ground improvement device 1. Therefore, even when the spring water pressure is high or the amount of spring water is large, the strength of the natural ground E can be surely increased, and the spring water can be stopped.

  Moreover, since the 1st packer 6 is expanded, hold | maintaining the state with which the chemical | medical material 3 press-fitted in the excavation hole 2 was pressurized with the 2nd packer 7, the chemical | medical material 3 is pressurized to the natural ground E The injection hole 4a can be opened while maintaining the above state. Therefore, the pressurized state can be maintained until the chemical material 3 is cured and the spring water stops.

  Further, after the first packer 6 is expanded, the second packer 7 is contracted and the cleaning water is injected into the feed pipe 4 so that the inside of the feed pipe 4 and the excavation hole 2 can be washed. All of the chemical 3 in the supply pipe 4 and the chemical 3 in the gap 16 can be removed. Therefore, the chemical material 3 does not exist around the feeding pipe 4 and the second packer 7, and the chemical material 3 remaining in the feeding pipe 4 and the medicine injected into the excavation hole 2 as in the prior art. Since the material 3 is not integrated and hardened, the ground improvement device 1 can be recovered. Thereby, the ground improvement apparatus 1 can be reused.

  In addition, since the tip of the ground improvement device 1 is provided with a tapered protrusion 11, the ground improvement device 1 can be inserted into the excavation hole 2 even when there is a large amount of spring water. If the first packer 6 is contracted after the material 3 is cured and the ground improvement device 1 is pulled out of the excavation hole 2, the adhesion can be easily removed.

  Furthermore, when it is difficult to remove the adhesion between the first packer 6 and the protruding portion 11 and the hardened medicine 3, the connection with the first packer 6 can be disconnected, The second packer 7 can be collected.

It is a figure which shows the state which installed the ground improvement apparatus which concerns on embodiment of this invention in the excavation hole provided in the face vicinity of the tunnel. It is the figure which expanded the excavation hole vicinity of FIG. It is a perspective view which shows the ground improvement apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the ground improvement apparatus which concerns on embodiment of this invention. It is the figure which showed the procedure which improves the ground using the ground improvement apparatus which concerns on this embodiment. It is the figure which showed the procedure which improves the ground using the ground improvement apparatus which concerns on this embodiment. It is the figure which showed the procedure which improves the ground using the ground improvement apparatus which concerns on this embodiment. It is the figure which showed the procedure which improves the ground using the ground improvement apparatus which concerns on this embodiment. It is the figure which showed the procedure which improves the ground using the ground improvement apparatus which concerns on this embodiment.

DESCRIPTION OF SYMBOLS 1 Ground improvement apparatus 2 Drilling hole 2a Hole bottom 2b Hole opening 2c Inner peripheral surface 3 Chemical material 4 Feeding pipe 4a Injection hole 6 First packer 7 Second packer 8 Chemical material supply means 9 Working fluid supply means 10 Washing water Supply means 11 Protrusion 12 Crack 13 Water channel 16 Clearance E Jiyama

Claims (3)

A ground improvement device that is inserted into a drilling hole formed in a natural ground and injects a chemical material for ground improvement from the drilling hole into the natural ground to improve the ground,
An injection hole that is open on a side surface near the tip is provided, and a feeding pipe that feeds the drug material;
A first packer connected to the distal end side of the injection hole of the feed pipe and capable of expanding and contracting by working fluid pressure;
A second packer that is provided on the base end side of the feeding hole of the feeding pipe and can be expanded and contracted by a working fluid pressure;
A chemical material supply means for supplying the chemical material into the feed pipe;
A working fluid supply means for supplying a working fluid for expanding and contracting each of the first packer and the second packer;
Cleaning water supply means for supplying cleaning water into the feed pipe ;
The ground improvement device according to claim 1, wherein the feeding pipe can be divided into a portion where the first packer on the tip side of the injection hole is attached and a portion on the base end side from the portion .   The ground improvement device according to claim 1, further comprising a protruding portion that is connected to a tip portion of the first packer and is tapered toward the tip direction. An injection hole that opens on the side surface near the tip is provided, and a feeding pipe that feeds a chemical for ground improvement,
A first packer connected to the distal end side of the injection hole of the feed pipe and capable of expanding and contracting by working fluid pressure;
A second packer that is provided on the base end side of the feeding hole of the feeding pipe and can be expanded and contracted by a working fluid pressure;
A chemical material supply means for supplying the chemical material into the feed pipe;
A working fluid supply means for supplying a working fluid for expanding and contracting each of the first packer and the second packer;
In the ground improvement method for improving the ground using a ground improvement device provided with cleaning water supply means for supplying cleaning water into the feed pipe ,
Inserting the ground improvement device into an excavation hole formed in a natural ground;
Inflating the second packer and closely contacting the inner peripheral surface of the excavation hole;
A step of injecting a chemical material into the excavation hole from the supply pipe through the injection hole, and injecting the chemical material into a natural ground;
Expanding the first packer in close contact with the inner peripheral surface of the excavation hole in a state where the second packer is in close contact with the inner peripheral surface of the excavation hole; and
Shrinking the second packer;
Injecting cleaning water into the excavation hole from the supply pipe through the injection hole, and cleaning the inside of the supply pipe and the excavation hole;
A step of shrinking the first packer after curing of the medicine injected into the ground;
And a step of removing the ground improvement device from the excavation hole.

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