JPH0988056A - Strainer pipe and installation method thereof and chemical injection method using strainer pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to prevent excavation water from flowing back in a strainer pipe and a discharge hole from being clogged by comprising a strainer pipe which is provided with a tip discharge hole at the tip and a peripheral surface discharge hole around above the tip discharge hole and an inner pipe provided with an inner pipe discharge hole at the tip. SOLUTION: A tip discharge hole 2 is provided at the tip of a strainer pipe 1 while a large number of peripheral surface discharge holes 3 are provided around there. The peripheral surface discharge holes 3 are closed with a seal material 5 coated over the outer peripheral surface of an inner pipe 4 fitted tightly inside slidably. An inner pipe discharge hole 4' is provided at the tip of the inner pipe 4. Then, during excavation time, excavation water is discharged from the inner pipe discharge hole 4' and discharged out to a grounding area as muddy water from an excavation clearance around the strainer pipe 1. Since the peripheral surface discharge hole 3 is clogged with the seal material 5, no excavation muddy water is allowed to flow back or the peripheral surface discharge hole 3 is not clogged with slime or gravel. The pipe 1 can be directly penetrated into the ground by excavating a hole even in a sandy soil bed or a gravel bed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strainer pipe used in a chemical liquid injection method, a pumping method, and the like, a method of installing the strainer pipe, and a chemical liquid injection method using the strainer pipe.

[0002]

2. Description of the Related Art After filling a sealing grout which cures softly into an injection hole previously drilled with a boring rod,
Insert and embed a strainer tube in this seal grout,
Cracking material is injected into this strainer pipe to generate cracks in the seal grout and the surrounding ground,
After that, insert the injection pipe with the double packer that can be expanded and contracted by air above and below the discharge hole at the tip inside the strainer pipe, and gradually raise the injection pipe from the lower layer injection step to the upper layer injection step, There is known a double packer method using a strainer tube which discharges grout while sealing with a packer at each step and injects the grout into a surrounding ground through a crack.

However, in this double packer method, since the strainer pipe could not be used for drilling, it was necessary to drill the injection hole by boring in advance, pull out the boring rod, and then erected the strainer pipe. There is a problem that installation requires a considerable amount of labor and cost, and the cost of the packer device is increased, the operation is troublesome, and when the packer expands and contracts, grout leaks and solidifies in the strainer tube. For this reason, it is inevitable to sequentially inject from the lower layer to the upper implantation step, so that there is a problem that the implantation grout easily escapes to an unspecified range.

Therefore, conventionally, an inner pipe is inserted into the strainer pipe while maintaining a gap around the inner pipe, and drilling water is pumped into the inner pipe and the gap between the strainer pipe and the inner pipe, and the tip of the strainer pipe and the surrounding area are drilled. Drilling while discharging drilling water from the discharge hole and the tip of the inner pipe, a method of installing a strainer pipe for chemical liquid injection to be installed at the required depth, and after this strainer is installed, the seal grout is pumped inside by pulling up the inner pipe Into the drilling gap from the tip through the tip of the strainer pipe and the surrounding discharge holes, and after the injection is completed, the inner pipe is stepped down from the top of the strainer pipe to the lower part while being fed under pressure. A chemical injection method using a strainer tube that discharges the injected grout from the discharge hole to break the seal grout and step inject into the surrounding ground is known That.

[0005]

In the above conventional strainer pipe, clogging due to gravel can be theoretically prevented by pumping drilling water between the pipe and the inner pipe. (A sudden change), there is a problem in that clogging of the surrounding discharge holes occurs, which hinders subsequent injection of a chemical solution and the like.

In addition, since drilling mud flows into the gap between the strainer pipe and the inner pipe to precipitate slime, the inner pipe becomes unable to slide, and in the case of injecting a chemical solution, grout is injected between the strainer pipe and the inner pipe. There was a problem such as running up from the gap.

[0007]

In order to solve the above-mentioned conventional problems, the present invention relates to a strainer tube 1 provided with a tip discharge hole 2 at the tip and a large number of peripheral discharge holes 3 around the top. A strainer tube comprising an inner tube 4 having an inner tube discharge hole 4 'at the distal end which is slidably and tightly fitted inside the strainer tube 1 so as to close the peripheral surface discharge hole 3 from the inside. Is proposed.

Further, according to the present invention, the tip discharge hole 2 is provided at the tip,
Further, a strainer tube 1 having a plurality of peripheral surface discharge holes 3 provided thereabove, and a sealing material 5 which is slidably and tightly fitted inside the strainer tube 1 to close the peripheral surface discharge holes 3 from the inside thereof. And an inner tube 4 provided with an inner tube discharge hole 4 ′ at a tip portion formed by coating the outer periphery of the strainer tube.

Further, according to the present invention, the tip discharge hole 2 is provided at the tip,
Further, the inner tube 4 is slidably fitted tightly inside the strainer tube 1 having a large number of peripheral surface discharge holes 3 provided thereabove so as to close the peripheral surface discharge holes 3 from the inside. Drilling water is pumped into the inner pipe 4 and the inner pipe discharge hole 4 ′ at the tip thereof
The present invention proposes a method for installing a strainer pipe, which is drilled while discharging drilling water through the tip discharge hole 2 of the strainer pipe 1 and is installed at a required depth.

Further, according to the present invention, a tip discharge hole 2 is provided at the tip.
The inner tube 4 is slidably and tightly fitted inside the strainer tube 1 provided with a large number of peripheral surface discharge holes 3 around the periphery thereof so as to close the peripheral surface discharge holes 3 from the inside. ,
Drilling water is pumped into the inner pipe 4 and a discharge hole 4 ′ at the tip thereof is formed.
After drilling water while discharging drilling water from the tip end discharge hole 2 of the strainer pipe 1 and installing it at a required depth, the inner pipe 4
The seal grout 8 having a low consolidation strength is pressure-fed into the inside of the hole while pulling it up from the inner tube discharge hole 4 ′ at the distal end thereof through the discharge hole 2, 3 on the distal end of the strainer tube 1 and the peripheral surface to form the inside of the drilling gap. After the injection is completed, the inner pipe 4 is gradually moved downward from the upper part of the strainer pipe 1 while the injection grout 9 which has been pumped into the inner pipe 4 is discharged from the inner pipe discharge hole 4 ′ to discharge the seal grout 8. The present invention proposes a chemical solution injection method using a strainer tube, which is characterized by performing a chemical solution injection method using a strainer tube 1 that breaks down and injects step into the surrounding ground.

[0011]

During drilling, drilling water is discharged from the inner pipe discharge hole 4 'at the distal end of the inner pipe 4 at the distal end of the strainer pipe 1, and becomes muddy water from the drilling gap around the strainer pipe 1 to the ground. Although it is discharged, the peripheral surface discharge hole 3 around the strainer tube 1 is closed by the sealing material 5 covering the outer peripheral surface of the inner tube 4 fitted therein or the outer periphery. The drilling mud does not flow backward, and the peripheral discharge holes 3 are not clogged with slime, gravel, etc., so that the sandy layer or gravel layer is reliably drilled and the strainer pipe 1 penetrates directly into the ground. Can be installed.

At the time of pouring, the seal grout 8 having a low consolidation strength is pressure-fed into the inner pipe 4 while being lifted, and the inner pipe 4 is discharged from the inner pipe discharge hole 4 'to the discharge holes 2, 3 at the tip and the peripheral surface of the strainer pipe 1. And after the injection is completed, the inner pipe 4 is pushed into the soft and hardened seal grout 8 in the strainer pipe 1 to be sequentially moved downward from the upper layer to the lower layer during the injection step while being pressure-fed therein. The injected grout 9 is discharged from the inner tube discharge hole 4 ′ to break the hardened seal grout 8 film and to discharge the peripheral surface discharge hole 3.
, The grout 9 is uniformly and reliably penetrated into each step range without escaping to the upper layer or lower layer of the ground, and a reliable injection effect can be expected.

In particular, when the step injection is performed by the inner pipe 4, the sealing material 5 around the inner pipe 4 is tightly fitted into the strainer pipe 1, so that the leakage above the injection grout 9 is reliably prevented.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a steel strainer tube according to an embodiment of the present invention; FIG. An inner pipe (single pipe or double pipe) 4 has an outer peripheral surface or an outer peripheral surface, or an elastic material such as rubber or synthetic resin, or a hard synthetic resin coated on the outer peripheral surface thereof. The peripheral discharge hole 3 is closed by a sealing material 5 made of metal or metal, and is slidably fitted tightly. An inner tube discharge hole 4 ′ is provided at the tip of the inner tube 4, and a swivel 6 is provided at the head. Is connected.

As shown in FIGS. 1 and 2, the inner pipe 4 is formed of at least a peripheral discharge hole 2 inside the strainer pipe 1 as shown in FIGS. It is possible to use a tube integrally formed of a material such as a synthetic resin or a metal having an outer diameter such that it fits tightly in a portion where is opened.

When the strainer pipe 1 is installed in the ground, drilling water is pumped into the inner pipe 2 as shown in FIG. 3 and the tip of the strainer pipe 1 is discharged from the inner pipe discharge hole 4 'at the tip. Drilling water is discharged through the discharge hole 2, and the strainer tube 1 is press-fitted in the axial direction while rotating to drill a hole.

At this time, the peripheral surface discharge hole 3 of the strainer tube 1
Is closed by the sealing material 5 covering the outer peripheral surface or outer periphery of the inner pipe 4, so that drilling mud flows back into the strainer pipe 1, and the gravel contained therein clogs the peripheral discharge port 3. However, the drilling mud smoothly circulates and flows upward along the gap between the strainer pipe 1 and the peripheral wall of the drill hole 7.

Therefore, even in the collapsing ground such as a sandy layer and a gravel layer, the peripheral discharge hole 3 of the strainer tube 1 is not clogged by the gravel in the muddy water, and the connecting pipe 1 ′ is connected to the strainer tube 1. When the pumping of drilling water is temporarily stopped, such as when jointing
Even if slime collects at the tip of the, the peripheral surface discharge hole 3 is not clogged.

In this way, the joint pipe 1'is jointed as necessary to drill a hole to the planned depth, and the strainer pipe 1 and the inner pipe 4 are directly drilled at the same time as the drilling, and the strainer pipe 1 is used. Then, the chemical injection method, pumping method, or water permeability test is performed.

For example, when the pumping method is carried out, the gap between the drilled holes is filled with sand and a still water grout (upper gap), the inner pipe 4 is pulled out from the strainer pipe 1, and a pumping pipe is inserted in place of the pipe. The underground water level is lowered by pumping the underground water flowing into the borehole 7 by the pump.

In the water permeability test, groundwater in the strainer pipe 1 is pumped up to a certain water level by a water pump and a water pump in the same manner as described above, and then the time until the groundwater rises and returns to the original water level is measured.

Next, when the chemical injection method is performed,
After installing the strainer tube 1 in the ground, as shown in FIG. 4 and FIG.
The seal grout 8 having a relatively small consolidation strength is pressure-fed and discharged from the inner tube discharge hole 4 ′.
From 3, it is filled into the hole 7 and the strainer tube 1 and hardened.

Next, as shown in FIG. 6, the inner tube 4 is pushed into the soft and hardened seal grout 8 in the strainer tube 1 and is gradually moved downward from the upper layer to the lower layer in a step of injection. The injection grout 9 pumped into the pipe 4 is discharged from the inner pipe discharge hole 4 ′ to break the cured seal grout 7 film and step-inject it into the surrounding ground. As shown in FIG. After completion, the strainer tube 1 and the inner tube 4 are pulled out as shown in FIG.

In this pouring step, since the pouring step is performed sequentially from the upper layer to the lower layer, the pouring grout 9 is prevented from running upward by the hardened soil layer of the upper step, and is moved downward by the groundwater pressure from below. It is possible to suppress the run-out and to uniformly penetrate the predetermined range without escaping into the unspecified range without limit, and to expect a reliable injection effect.

Further, since the inner pipe 4 is inserted into the seal grout 7 and injected, the grout 9 can be reliably prevented from flowing out from the drilling gap to the ground by the packing effect of the seal grout 8.

[0026]

As described above, according to the present invention, at the time of drilling, drilling water is discharged from the inner pipe discharge hole at the distal end of the inner pipe at the tip of the strainer pipe, and the drilling water flows through the drilling gap around the strainer pipe. However, since the peripheral surface discharge holes around the strainer tube are closed by the sealing material covering the outer peripheral surface or outer periphery of the inner tube fitted inside the strainer tube, The drilling mud does not flow backward, causing slime to settle inside, and the peripheral discharge holes are not clogged with slime, gravel, etc. It can be installed directly in the ground and can prevent the inner pipe from being pulled out.

At the time of casting, the inner pipe is penetrated into the soft and hardened seal grout in the strainer pipe, and is moved downward from the upper layer to the lower layer in the order of injection step. Since the grouted seal grout film is broken and injected into the surrounding ground, the grout penetrates uniformly into each step range without escaping to the upper and lower layers of the ground, and a reliable injection effect can be expected.

In particular, when the step injection is performed by the inner pipe, since the sealing material on the outer peripheral surface or the outer circumference of the inner pipe is tightly fitted in the strainer pipe, it is possible to surely prevent the leak from flowing upward from the injection grout. it can.

[Brief description of drawings]

FIG. 1 is a partial vertical sectional front view showing an embodiment of a strainer tube of the present invention.

FIG. 2 is a cross-sectional plan view of the strainer tube of FIG.

FIG. 3 is a vertical cross-sectional front view showing one embodiment of the step of the injection construction of the present invention.

FIG. 4 is a longitudinal sectional front view showing another embodiment of the pouring process of the present invention.

FIG. 5 is a vertical cross-sectional front view showing another embodiment of the pouring process of the present invention.

FIG. 6 is a vertical sectional front view showing another embodiment of the pouring process of the present invention.

FIG. 7 is a vertical cross-sectional front view showing another embodiment of the pouring process of the present invention.

FIG. 8 is a longitudinal sectional front view showing another embodiment of the pouring process of the present invention.

FIG. 9 is a partial vertical sectional front view showing another embodiment of the strainer tube of the present invention.

FIG. 10 is a cross-sectional plan view of the strainer tube of FIG. 9;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 strainer pipe 1 ′ connection pipe 2 tip discharge hole 3 peripheral discharge hole 4 inner pipe 4 ′ inner pipe discharge hole 5 sealing material 6 swivel 7 drilling 8 seal grout 9 injection grout

Claims (4)

[Claims] 1. A strainer tube having a distal end discharge hole at a distal end thereof and a plurality of peripheral surface discharge holes provided thereabove, and a slide inside the strainer tube so as to cover the peripheral surface discharge hole from the inside. A strainer tube comprising: an inner tube provided with an inner tube discharge hole at a tip portion freely and tightly fitted. 2. A strainer pipe provided with a tip discharge hole at a tip thereof and a plurality of peripheral surface discharge holes provided thereabove, and slidably and closely fitted inside the strainer pipe,
A strainer pipe comprising: an inner pipe provided with an inner pipe discharge hole at a distal end formed by covering the outer periphery with a sealing material for closing the peripheral surface discharge hole from the inside. 3. Inside a strainer tube having a distal end discharge hole at a distal end and a plurality of peripheral surface discharge holes provided above the distal end discharge hole, the inner tube is slidably and densely closed so as to cover the peripheral surface discharge hole. The drilling water is pumped into this inner pipe and drilled while discharging the drilling water from the inner pipe discharge hole at the distal end through the distal discharge hole of the strainer pipe, and installed at the required depth. Strainer pipe installation method. 4. An inner tube is slidable in a strainer tube having a distal end discharge hole at a distal end and a plurality of peripheral surface discharge holes provided thereabove so as to close the peripheral surface discharge hole from the inside thereof. Drilling water was pumped into this inner pipe and drilled while discharging drilling water from the inner pipe discharge hole at the tip through the tip discharge hole of the strainer pipe. Then, while raising the inner pipe, a seal grout having a low consolidation strength is pumped into the inner pipe, and injected into the drilling gap from the inner pipe discharge hole at the distal end through the discharge hole at the distal end and the peripheral surface of the strainer pipe. After the injection is completed, the inner grout is stepped downward from the upper portion of the strainer pipe in a stepwise manner, and the grout pumped into the inner grout is discharged from the inner pipe discharge hole to break the seal grout and break the seal grout. Step injection into A chemical solution injection method using a strainer tube.