JPH0657939B2 - Ground improvement method and equipment by injection of fine powder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) This explanation is for all leaks and air leaks from the ground surface or to excavated sites under construction or to completed underground structures, and even harmful It is used for preventing gas leakage, forming a gas / liquid leakage prevention wall in the ground, and increasing the strength of those grounds.

(Prior Art) Conventionally, in order to prevent water leakage, air leakage, and harmful gas leakage from the ground, liquid containing cement, bentonite, chemical liquid, etc., directly or Use an injection pipe, etc. to inject water to the surface or underground to form a water stop, air wall, impermeable water / air layer, or in the case of an underground structure, penetrate the underground structure to contact the underground structure. I was injecting the improving drug by inserting a chemical injection pipe into the ground.

However, in all of these methods, the ground improvement material such as cement, bentonite, or chemical liquid is injected in a state of being suspended or dissolved in a liquid such as water, so that the particles of cement or bentonite are interstices in the soil It is difficult to enter, and because it is a liquid, it is impossible to evenly inject it into the ground, and water and air walls cannot be formed uniformly. I couldn't make a wall.

Further, since a liquid such as water is used, the weight becomes large and a large-scale injection device is required.

As an improved version of this, Japanese Patent Application Laid-Open No. 60-138112
A method for pneumatic grouting, which comprises blowing compressed air into the ground to form an air passage in the ground, and then injecting a hardening agent in the form of powder or suspension into the air passage. In particular, Japanese Patent Publication No. Sho 49-12364,
Aerosol grout for spraying a mixture of suspension grout or solution grout with an aerosol agent together with compressed air, as clearly shown on page 2, right column, lines 2 to 32 and in FIGS. 3 and 5. Techniques for construction methods are known. However, the former is a two-step method in which an air passage is first formed by compressed air and then a hardening agent is injected into the air passage, which is time-consuming and difficult to control such as pressure. In addition, the latter uses a grout material containing a liquid, and thus the weight of the grout agent is extremely large, which requires a large-scale device and is restricted by a work site.

(Problems to be Solved) In the present invention, a fine powdery material such as cement, fly ash, talc, diatomaceous earth, and magnesite is used to easily, uniformly and surely form a (gas or liquid leakage prevention wall). The development of construction methods and equipment is a problem to be solved.

(Means for Solving) The means developed by the present invention for solving the above problems will be described below, but the terms used in the specification of the present application will be completed prior to the description. Fine particles such as cement are cement, fly ash, talc, (talc) diatomaceous earth,
Magnesite, quartz stone, alumina, iron powder, fine metal powder,
The average particle size of carbon, polyethylene glycol, etc. is about 0.
It is used as a term that means a granular material of 1 to 20 μm.

First, in order to solve the above-mentioned problems in the present application, only those in which fine particles of cement or the like are suspended in a gas are simply blown into the ground by a pipe or an injection pipe together with compressed air, The basic solution principle is to prevent the leakage of gas and liquid by forming a dense stratum over a certain range (depth) by making the ground clogged with fine particles such as cement. is there.

Further, in the present invention, based on the above basic solution principle, several more concrete ground improvement methods and devices used therefor have been developed.

That is, as a method of infiltrating fine particles of cement or the like into the ground, only those in which fine particles of cement or the like are suspended in gas are put into the ground by a pipe or injection pipe together with compressed air. A ground improvement method characterized in that the ground is clogged just by blowing into it to prevent gas and liquid from leaking.

The ground is clogged only by blowing fine powder or granules such as cement coated with silicone into the air with a pipe or injection pipe together with compressed air. Ground improvement method to make the ground hard to leak gas and liquid.

Was developed. Further, as a device for carrying out these construction methods, there is a blow-out pipe in which a cap-shaped pack is attached near the tip of a pipe having an opening. A recovery outer pipe is provided around the blow-out pipe so as to cover it completely. Blown pipe.

It consists of an outer tube having an opening in the peripheral wall and an inner tube that is movably accommodated in the outer tube in the axial direction. An opening is formed near the tip of the inner tube. A blowing device in which a packer whose tip contacts the inner wall of the outer pipe is attached to the outer periphery of the inner pipe located at the upper and lower ends in the axial direction of the holed portion.

An opening is formed near the tip of the pipe, and a disk-shaped packer whose tip contacts the boring hole is attached to the outer circumference of the pipe located at the upper and lower ends in the axial direction of the portion where the opening is formed. Blowing device.

Was developed.

(Example) Each invention of the present application will be described with reference to the drawings.

The first invention of the present application (described in claim 1) and the second invention (described in claim 4) will be described with reference to FIG.

In FIG. 1, (1) is a blow pipe, and a pack (2) is connected to the tip of the blow pipe. The pack (2) may be integrally formed, or may be a separate body attached by some means.

The packing (2) is provided with a packing (3) made of rubber, felt, elastic body containing air, elastic body such as bellows body containing liquid / gas, etc., so that it can be closely attached to the ground surface. I am good at sex.

Any packing (3) can be selected according to the unevenness of the ground surface. Further, the pack (2) is attached to the blow pipe (1) so as to be precessed, that is, it can be changed at an arbitrary angle with respect to its axial direction, which is included in the present invention. Further, the adhesion to the ground surface is improved.

Further, in the figure, (8) is a container containing a fine powder such as cement suspended in a gas, (7)
Is a pump for pumping it to the blow pipe (1).

Further, (10) is a support for receiving the reaction force of the blowing pipe (1) due to the blowing action, but this is not always necessary.

A construction method for improving the ground by using such a blowing device will be described.

First of all, a fine powdery substance such as cement suspended in a gas is blown from the container (8) by the pump (7).
It is pressure-fed to (1) and is blown into the ground (14) while being urged in the diffusion direction by the shade-shaped pack (2).

Fine ground particles (15) such as cement that are blown into the ground (14) are sent into the gap between the soil particles (16), and the gap is closed to create a dense ground that prevents gas and liquid leakage. Will be improved.

FIG. 2 shows another embodiment of the first aspect of the invention and a third aspect of the invention (described in claim 7), which is a blow pipe (11).
Unlike the example shown in Fig. 1, the blow pack (12) has a cap-like diameter at its tip and the packing (13) is attached to the periphery of the tip. Absent.

In this embodiment, the blow pipe (11) and the blow pack (12) have outer circumferences, respectively, a suction pipe (4) and a packing (6) around the tip periphery.
Is provided with a suction pack (5), by which between the blow pack (12) and the ground surface, further,
The air blown into the ground and some fine particles such as cement are collected.

Furthermore, by the suction action of the suction pipe (4) and the suction pack (5), the reaction force of the blow pipe (11), the blow pack (12), etc. due to the blowing action can be mitigated. You can omit the device that receives it, or you can make it simple.

Further, in the figure, (8) is a container for accommodating fine particles of cement or the like suspended in a gas, and (7) is a pump.

A construction method for improving the ground by using such a blowing device will be described.

First, a fine powder or granules such as cement suspended in a gas is blown into a pipe (1) from a container (8) by a pump (7).
It is pressure-fed to 1) and is blown into the ground (14) by being urged in the diffusion direction by a hat-shaped blow pack (12).

The ground that can prevent leakage of gas and liquid by injecting fine particles (15) such as cement injected into the gap of the soil grain (16) in the ground (14) and closing the gap to make a dense ground. To improve.

And in this embodiment, from the gap between the packing (13) attached to the peripheral edge of the tip of the blow pack (12) and the ground surface, and once blown into the ground (14) from the gap of the soil particles (16). Fine powder particles such as cement that leaked to the surface of the earth and earth and sand containing it are collected by the blowing pack (5), and blown into the pipe.
It is collected in the collection container (9) through (4).

Next, a method and an apparatus for forming a wall for preventing leakage of liquid or gas in the ground will be described with reference to FIGS. 3 and 4.

Fig. 3 shows a state in which fine particles of cement or the like are suspended in a gas in the ground (14), or a silicone oil coating is formed on the outer periphery of the fine particles of cement or the like (15). Send things together with compressed air.

The injection pipe (20) and an outer pipe arranged substantially concentrically outside the injection pipe (20)
It consists of (24) and. The front end of the injection pipe (20) is a closed bottom portion (23), and the peripheral wall near the front end is provided with a plurality of injection pipe openings (21) (for injection) in a radial direction over a fixed length in the axial direction. 21) is perforated.

On the other hand, the outer wall of the outer tube (24) also has an outer tube opening (2
5) is perforated. And the outer periphery of the front and rear ends of the range where the opening of the injection pipe (20) is perforated, the inner wall of the outer pipe (24), the disk-shaped packer (22), the tip of which is in contact, (22)
Is fixed. In order to form a liquid / gas leakage prevention wall at an arbitrary position in the ground by using such a device, as shown in FIG. 7, first, a boring machine is used to form a boring hole at an arbitrary position. Open inside and outer tube there
Insert (24) and injection tube (20) to required depth. Outer tube (24)
And when the installation of the injection pipe (20) is completed, by the pump (7),
Fine powder such as cement (15) or fine powder such as cement with a coating formed of silicone oil (15)
Only those in a state of being suspended in the gas are sent into the injection pipe (20) together with the compressed air, and sent out of the injection pipe (20) through the injection pipe opening (21).

The air sol, etc. exiting the injection pipe (20) is blown out into the space between the inner wall of the outer pipe (24) and the outer wall of the injection pipe (20). This space has two disc-shaped packers (upper and lower). 22) and (22) create a closed space, resulting in high pressure and the outer tube opening (25) of the outer tube (24).
It is sent more into the surrounding ground.

Then, through the (16) gap of the soil grain, the fine powder grain (15) such as cement is sent to a considerable depth (determined by the sending pressure and the resistance value of the soil), and the soil grain gap in the ground is cleared. Will be filled.

In this way, the soil density increases over a certain depth.

This state is shown in detail in FIG.

That is, it becomes as shown on the left side of the dashed line in FIG.

When this work is completed, the injection pipe is pulled up by the opening length "L" of the injection pipe (20).

When the injection pipe (20) is pulled up, both the upper and lower packers (22), (22) fixedly attached to it are also pulled up accordingly.

In this way, with the injection pipe (20) pulled up one step, the previous injection work is performed, and by repeating such work, water blocking walls and gas leakage can be achieved over the required depth in the ground. Can form walls.

The work of pulling up the injection pipe (20) may be performed intermittently or continuously and slowly.

Next, FIG. 4 will be described.

Reference numeral (30) in FIG. 4 is an injection pipe, and the tip portion (33) thereof is tightly closed. Then, on the peripheral wall near the tip of the injection pipe (30), a plurality of injection openings (3
1) is drilled.

Then, the boring holes (2
Disk-shaped packer (32) whose tip contacts the inner wall (34) of 6),
(32) is fixed. In order to form a gas / liquid leakage prevention wall in the ground using such a blowing device, first of all, only the fine powder particles (15) such as cement suspended in a gas container are used. From the (8), pump (7) to the injection pipe (3
Pump to 0).

In the case where the fine powder particles such as cement that have been pumped are suspended in the gas, the bottom part (33) of the injection pipe (30) is tightly closed, so the injection pipe (30) is injected through the injection pipe (30). ) Gush out.

The outer space of the opening where the injection opening (31) of the injection pipe (30) is formed is the disk-shaped packers (32) and (32) attached to the outer circumference of the upper and lower ends of the opening and the boring hole. (26) It is a closed space due to the inner wall, the pressure rises almost in proportion to the blowing amount, and the fine ground particles such as cement suspended in the gas are the surrounding ground (14) It is blown in. Fine particles of cement etc. in a state where fine particles of injected cement etc. are suspended in gas (15)
Is sent into the soil grain gap and fills the gap. This state is shown in detail in FIG.

That is, what was in the state of only the soil particles (16) as shown on the right side of the chain double-dashed line in Fig. 6 is filled with the fine powder particles (15) such as cement and the gap is changed to a dense ground. When a sufficient blowing operation is completed, the injection pipe (30) is axially pulled up by a length of "L", and the above operation is repeated again to form a gas / liquid leakage prevention wall over a desired depth.

The withdrawal of the injection pipe (30) may be performed intermittently or continuously and slowly.

Next, another embodiment of the first to third inventions, that is, a construction method and apparatus for improving the ground on the side opposite to the wall of the underground structure will be described.

If gas or liquid leaks from the wall (42) of the underground structure, drill a hole near the wall so that the injection pipe (40) can be inserted, and the tip of the injection pipe (40) is opposite. Push down to the ground (44) that is in contact with the side wall. The injection pipe (40) is connected to the container (8) only for the pump (7) and the fine powder particles (15) such as cement suspended in the gas. Are pumped into the injection tube (40). When a fine powder such as cement that has been pumped to the injection pipe is suspended in the gas, it is blown into the ground (44) through the opening (41) formed at the tip of the injection pipe (40). . As a result, the fine powder particles (15) such as cement are pushed into the soil particle gaps in the ground (44), filling the gaps and changing the soil quality to a dense one. This state is shown in FIG. 6, but since it is the same as the previous example, further explanation is omitted.

(Effects) According to the first invention of the present application, only a fine powder or granular material such as cement suspended in a gas is pressed into the gap of the ground together with compressed air. It is possible to form a dense soil over a deep layer, and to form a leak preventive wall that is almost impermeable to gas or liquid in arbitrary ground.

Further, according to the second invention of the present application (claim 4), fine powder particles such as cement can be blown into a desired depth over a required area from the ground surface of any terrain, so that it can be easily carried out. A gas / liquid leakage prevention wall can be formed over the required range.

Further, according to the third invention of the present application (claim 7), since the suction pipe is provided, the blow reaction force can be weakened,
Blowing can be done smoothly.

Further, according to the fourth invention of the present application (Claim 11), since there is an outer tube having substantially the same shape as the boring hole, there is little leakage and efficient injection work can be performed, and high pressure can be obtained. Fine particles can be blown deep into the ground.

Further, according to the fifth invention of the present application (claim 12), it is possible to efficiently inject fine powder particles such as cement by effectively utilizing the packer with a simple device of one injection pipe.

According to these inventions, only fine powders such as cement and those with a silicone coating formed on them are suspended in a gas and blown into the ground through a pipe or injection pipe together with compressed air. The ground can be clogged with the fine powder particles such as cement just by inserting, and a dense stratum can be formed over a certain range (depth) to prevent gas and liquid from leaking.

Further, in these inventions, since neither liquid or slurry-like ground solidifying agent is used at all, water is not used at all, a large-scale device is not required, a work site is not contaminated, and construction can be performed in a narrow place. In addition, riding on the flow of compressed air, 0.1-20
Floating fine particles of cement or the like having a very small average particle size of μm and those having a silicone coating formed thereon rapidly and evenly penetrate deep into the ground.

Although not a direct effect of the present invention, the fine powder particles such as cement that have entered the ground are solidified by reacting with the water contained in the ground after a certain amount of time to solidify. Since it becomes a solid wall, it is possible to more reliably prevent gas and liquid from leaking.

[Brief description of drawings]

FIG. 1 shows an embodiment of the first invention and the second invention of the present application. FIG. 2 shows another embodiment of the first invention of the present application and an embodiment of the third invention of the present application. FIG. 3 shows another embodiment of the first invention of the present application and an embodiment of the fourth invention of the present application. FIG. 4 shows another embodiment of the first invention of the present application and an embodiment of the fifth invention of the present application. FIG. 5 shows another embodiment of the first invention of the present application. FIG. 6 illustrates the principle of the present invention and shows how fine powder particles such as cement are blown into the soil particles of the ground. FIG. 7 shows a state in which a gas / liquid leakage prevention wall is formed in the ground. 1 .... Blowing pipe 2 .... Pack 3 .... Packing 4 .... Suction pipe 5 .... Suction pack 6 .... Packing 11 .... Blowing pipe 12 .... Blowing pack 13 .... Blowing packing 15 .... Fine powder such as cement Granule 16.… Soil grain 20.… Injection tube 21.… Injection tube opening 22.… Packer 24.… Outer tube 25.… Outer tube opening 26.… Boring hole 30.… Injection tube 31.… Injection tube opening 32. .. Packer 40 .. Injection tube

Claims (12)

[Claims] 1. Only a fine powder of cement or the like having an average particle diameter of 0.1 to 20 μm suspended in a gas is blown into the ground together with compressed air through a pipe or an injection pipe. Then, the ground improvement method is characterized in that the ground is clogged so that gas and liquid do not leak easily. 2. The ground improvement method according to claim 1, wherein the fine particles of cement or the like having an average particle diameter of 0.1 to 20 μm form a coating film of silicone. 3. A fine powder such as cement having an average particle diameter of 0.1 to 20 μm is blown into the ground which penetrates the wall of an underground structure and is in contact with the wall surface.
The ground improvement method according to item 2 or item 2. 4. The ground is clogged by only blowing fine particles of cement or the like having an average particle diameter of 0.1 to 20 μm in a state of being suspended in a gas into the ground. A device for making a ground in which gas or liquid does not easily leak, and a tube body having an opening at the tip, and a position of the tube body that is further closer to the root than the position at which the opening is formed. In addition, the average particle size consisting of a cap-shaped blow pack attached in close contact over the entire circumference of the pipe has an average particle size of 0.1 to 0.1.
Device for injecting fine particles such as 20 μm cement. 5. The apparatus for injecting fine particles of cement or the like according to claim 4, wherein packing is attached to a peripheral portion of a free end of the cap-shaped injection pack. 6. A fine powder of cement or the like according to claim 4 or 5, wherein the cap-shaped blow pack is mounted so as to be able to swing at an arbitrary angle with respect to the axial direction of the tubular body. Granule blowing device. 7. A ground is clogged by only blowing fine particles of cement or the like having an average particle diameter of 0.1 to 20 μm in a state of being suspended in a gas into the ground. A device for making a ground in which gas or liquid does not easily leak, and a tube body having an opening at the tip, and a position of the tube body that is further closer to the root than the position at which the opening is formed. In addition, the average particle size consisting of a cap-shaped blow pack attached tightly around the entire circumference of the pipe body and a recovery outer pipe provided so as to surround the blow device has an average particle diameter of 0.1 to 0.1.
Device for injecting fine particles such as 20 μm cement. 8. The apparatus for injecting fine particles of cement or the like according to claim 7, wherein the recovery outer tube comprises a tube body and a cap-shaped recovery pack attached to the tip thereof. 9. A cap-shaped blow pack and / or a cap-shaped recovery pack are mounted so as to be inclined at an arbitrary angle with respect to the axial direction of the pipe body to which they are mounted. Apparatus for injecting fine particles of cement or the like according to item 7 or 8 of the above. 10. The device for injecting fine particles of cement or the like according to any one of claims 7 to 9, wherein the recovery outer tube is connected to a suction device. 11. The ground is clogged by only blowing fine particles of cement or the like having an average particle diameter of 0.1 to 20 .mu.m suspended in a gas into the ground. An apparatus for making a ground in which gas or liquid does not easily leak, which has a cross-sectional outer shape that is substantially the same as the cross-sectional shape of a pre-drilled boring hole, and an outer tube having an opening in the peripheral wall,
The inner pipe is housed in the outer pipe so as to be movable in the axial direction, and the inner pipe has an opening formed in the peripheral wall over an appropriate length in the axial direction. A disk-shaped packer whose tip contacts the inner peripheral wall of the outer tube is attached to the outer peripheral portion of the inner tube, and the average particle size is 0.1 to 20 μm.
A device for injecting fine particles such as cement. 12. A ground is clogged by only blowing fine particles of cement or the like having an average particle diameter of 0.1 to 20 μm in a state of being suspended in a gas into the ground. A device for making the ground hard to leak gas or liquid, which has an opening formed near the tip of the pipe over an appropriate length in the axial direction, and the upper and lower ends of the opening in the axial direction. A disk-shaped packer whose tip is in contact with the inner wall of the boring hole is attached to the outer peripheral portion of the pipe located at the above-mentioned section, and the average particle size is 0.
A device for injecting fine particles such as cement of 1 to 20 μm.