JP2000257057A - Ground injection device for ground and injection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent disorder penetration of a curing agent on each stage because of blockade of a curing agent discharge port due to a cavity on a drilled hole on the outside of an outer tube, to carry out injection of the curing agent favorably in construction performance and at one time in all stages, to shorten a construction period and to reduce cost in duplex tube double packer injection construction. SOLUTION: Bag bodies 26 provided on a plural number of stages in the axial direction of an outer tube 21 are expanded and closely fastened on a hole wall of a drilled hole 7 without interposing seal grout in the drilled hole formed on a natural ground, and the ground is consolidated. Consequently, it is possible to constantly and penetratively injecting specified quantity of a curing agent in the ground natural ground in large quantity as a whole as designed and to certainly construct a large diametrical and lengthy molded body under the ground regardless of resistance pressure and falling of the hole wall through a pressure space between each of packers from exhaust ports of exhaust nozzles on a plural number of the stages provided on an inner tube and to certainly construct a large diametrical lengthy molded body underground even when a hole wall falling phenomenon, etc., are caused.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The disclosed technology relates to a technology for improving a ground, preventing liquefaction of the ground, and reinforcing the ground during deep excavation. Thus, the present invention relates to the field of injection of a hardening material into the ground for ground improvement of a large-capacity ground.

[0002]

2. Description of the Related Art Conventionally, a stabilization technique for liquefaction of a ground having fluidity due to the presence of groundwater, including a ground around a ground excavation and a deep underground construction, has been performed by using an injection pipe into a drilled hole formed in the ground. Has been widely used in which the ground is partially or broadly reinforced by injecting a hardening material such as a cement mortar or a chemical solution by inserting a mortar.

[0003] Various development and improvement studies have also been made on the technology used for the reinforcement and stabilization of the ground. Recently, a double pipe double having a bag body 5 as shown in FIG. The injection method using the piper 1 of the packer system has come into practical use, and the seed method forms a predetermined hole in the ground of the ground, fills the inside of the hole with a seal grout 13, The tube 1 is inserted into the formed hole, the sleeve 4 'is opened from the inner tube inserted into the outer tube through the discharge port 3' provided in the bag 5, and the filler 6 such as cement milk is opened. Is filled, and the bag body 5 is inflated and tightly fastened to the hole wall of the drilled hole. A hardening material is injected, the sleeve 4 fitted on the outer side of the discharge port 3 of the pipe 1 is opened, the seal grout is split, and Through the drilling of the hole wall, and is to stabilize by performing the injection of curing material in the ground.

However, when the hardening material is to be widely injected from a single injection pipe into a wide area of the ground as in the liquefaction prevention method, the hardened material penetrates into the ground by sealing with a seal grout around the injection pipe. Therefore, it is difficult to uniformly permeate a large amount of discharge per minute uniformly for a long time over a wide range.

[0005] As shown in FIG. 8, a hole 8 of a predetermined size is formed in a ground 7 of the ground, and a discharge port 9 of a predetermined size formed at a predetermined pitch in the axial direction is formed inside the hole 8. An outer tube 12 having a number of openings, a rubber sleeve 10 banded around each discharge port 9 and provided with a strainer 11 is inserted through a seal grout 13, and an inner tube is inserted into the outer tube 12. 17 are inserted with the rubber packers 14, 14 at predetermined intervals, a space 15 is formed between the rubber packers 14,
A predetermined number of holes are formed in the axial direction of the inner pipe 17 so that the discharge port 9 of the outer pipe 12 and the injection port 16 of the inner pipe 17 communicate with each other in the space 15 between the rubber packers 14, and a predetermined stroke The predetermined hardening material fed from the hardening material passage 18 in the inner tube 17 by the step-up method in the above passes through the injection port 16 of the inner tube 12, passes through the space 15 between the rubber packers 14, 14, and passes through The rubber sleeve 10 is opened through the discharge port 9 of the above, and is injected into the ground of the ground through the splitting of the sleeve grout 13 in the hole wall of the hole 8.

Reference numeral 19 designates a discharge port 1 of the outer tube 17 from the hardening material passage 18 through the injection port 17 of the inner tube 17 through the space 15.
2 shows the path of the hardening material that splits the sleeve grout 13 and penetrates and injects it into the ground of the ground.

[0007] 10 'is a rubber sleeve,
It is provided around the discharge port of the outer tube located outside the space 15 between the packers 14 and 14.

In the packing tube 1 'of the packer type shown in FIG. 8, the hardening material in a step-up system of a predetermined stroke from the hardening material passage 18 in the inner tubes 17, 17 is supplied to the outer tube 12 by a predetermined stroke. It is possible to split the outer sleeve grout 13 and to penetrate the ground of the ground.
As shown in FIG. 10, even if the resistance pressure of the ground outside the discharge port changes in response to the pump pressure, that is, the pressure in the inner pipe 17, the injection port 16 of the pore in the inner pipe 17 changes. (For example, in FIG. 9, the aperture is 1.0 mm, and in FIG.
9), even if the outer resistance pressure changes to some extent, the discharge flow rate from the injection port 16 is, for example, in FIG. 9, when the pipe pressure is 50 kg / cm ² , and the resistance pressure of the ground is 0 to 30 kg / cm ² . 4.5 liters
It has been experimentally confirmed that an injection amount of / min was obtained, and also in FIG. 10, there was almost no change at 9 l / min, which was almost constant.

However, in the above-mentioned construction method, in actual construction, the depth of the sleeve grout located between the outer pipe and the borehole wall is settled in the borehole or mixed with the sand due to the collapse of the sand from the periphery. Inconsistently solidifies in the direction, making it difficult to inject and inject the injection liquid.

[0010]

In the double packer system shown in FIG. 7 as well, in the injection mode in which the seal grout of the hardening material is split by a predetermined stroke step-up system, a uniform injection flow rate is in principle possible. It should be possible to obtain the seal grout 1
Due to the partial shading of 3 and the change in the solidification state due to the change in density due to the breakage of the drilled wall, etc., it does not work according to the principle, and it is not possible to expect a uniform injection of a predetermined amount corresponding to the inner pipe pressure and the injection port diameter. There were drawbacks.

This makes it impossible to simultaneously inject a predetermined amount from a plurality of discharge ports, and it becomes necessary to perform one-by-one injection in a short injection stage.

Therefore, the conventional method of injecting the ground into the ground has a drawback that the liquefaction-preventing construction of the ground having a large area cannot be performed efficiently.

As described above, in the conventional injection means, the longer the injection stage length is, the more the soil properties of the surrounding ground change. There is a neck that makes it difficult to penetrate into the surrounding ground.Therefore, if a seal is formed by a sleeve grout around the injection pipe, the opening to the surrounding ground becomes small due to the presence of the sleek grout, so the discharge per minute If the amount is increased, the injection pressure becomes excessive, and if it continues to penetrate for a long time, there is a bottleneck that the gelled substance closes the opening of the seal grout around the injection tube and hinders long-time injection.

[0014]

SUMMARY OF THE INVENTION In view of the above-mentioned technical points of ground injection, the inventor (applicant) needs to economically improve a vast amount of soil with a hardening material, such as construction for liquefaction prevention work. One injection stage is long, and the discharge rate per minute per stage is large. Injecting a large amount of the chemical solution continuously for a long time per stage and injecting a large amount of the chemical solution, ie, permeation and consolidation over a wide range, that is, either of FIGS. Of the liquefaction prevention work and the ground improvement by injecting hardening material into the deep ground as described above, changes in the soil properties of the ground and the collapse of the hole walls of the boreholes formed in the ground Even if the resistance pressure against etc. changes, the injection is performed in a state where the stable discharge amount is constant, and the improvement of the large volume soil volume is carried out for a long time by the large amount of injection as designed,
In addition, an excellent ground injection device that is uniformly injected into the large injection stage at a stretch and solidifies, so that the construction of the ground in the ground can be performed as designed, which is beneficial to the field of civil engineering technology in the construction industry and It does not provide a construction method.

The applicant has devised a new construction method based on the above-mentioned matter. This construction method has the function of the conventional double-pipe double packer construction method and also adapts to the soil properties from sandy soil to cohesive soil. It is a revolutionary injection technology that can make rational injection improvements and contributes to shortening the construction period.

The principle of the new injection method is briefly described with reference to FIG. 12. As shown in FIG.
As shown in (b), the injection outer tube 21 with the bag 26 attached thereto is erected, and as shown in (c), the inner tube 28 is inserted into the outer tube 21.
Is inserted into the bag body 26 to fill and inject the hardening material into the bag body 26 to form a pack with respect to the drilled hole and strengthen the consolidation 26 'of the surrounding ground, and as shown in FIG.
To insert the osmotic hardener

[0017]

SUMMARY OF THE INVENTION In order to solve the above-described problems, an inflatable bag body made of a hardening material is fitted. A multi-stage hardening material discharge port is formed in the shank of the outer tube that is attached, and a hardening material injection port having the same multi-stage fine holes is formed in the inside, and the injection port is sandwiched between the injection ports. Wherein the inner tube having a plurality of stages of packers interposed therebetween is inserted into the outer tube, and a space formed between the inner and outer tubes is formed in a plurality of stages in the axial direction. At least one bag is attached to the shank of at least one, and at least one hardening material injection port is provided between at least one hardening material discharge port and a plurality of packers of the inner pipe on one side of the outer pipe bag body. The hardening material discharge port and the hardening material injection port are That they are communicated with each other in the same space that is 隔成 in direction to the first backbone.

[0018] The hardening material injection port of the inner tube is formed of fine pores so that the total area thereof is smaller than the cross-sectional area of the inner tube.
Due to the small diameter, the hardening material is sprayed into the space, and the present invention has an inner pipe that is inserted into an outer pipe provided with a plurality of discharge ports and injects the hardening material into the ground. A second basic structure of the injection device, wherein the inner pipe is configured to simultaneously inject the hardening material from at least three packers expanded by a fluid and a plurality of injection ports located between the packers. And

In the above aspect, a pressure sensor may be placed in each of the separated spaces, and an inflatable bag made of a hardening material may be attached to the plurality of hardening material discharge ports. A method of injecting a hardening material into the ground through a plurality of hardening material discharge ports formed in a shank of the outer tube by inserting an outer tube having Is expanded with a hardening agent so as to be fastened and fixed to the hole wall of the drilled hole, and a hardening material is injected from an inner pipe having a plurality of injection ports, and penetrates into the ground from a discharge port of the outer pipe. The technical measures were taken with the third core as the main purpose.

In the above, the formation of the packer by injecting the hardening material into the bag generally precedes the injection into the ground, but even if the injection into the bag and the injection into the ground are performed simultaneously, Since the injection amount is small, a packer is formed at an early stage, and thereafter the injection into the ground is continued.

In the above, the construction is performed rapidly by injecting a quick-setting mortar or a flash solution into the bag.

[0022]

According to the above construction, the construction order is described. The technique of the invention of this application is such that the hardening material which has developed the superiority of the double pipe double packer method can be injected into the ground. It has a filling inner tube with a special structure, and a bag inserted into the outer filling tube, for example, every 2 meters, is filled with cement milk or a hardening material having a gel time of instantaneous setting to long setting. Then, the ground disturbed by drilling and the gap between the injection outer pipe are brought into close contact with each other, and the ground constrained every 2 meters or the like by a strong packer action as one stage, and the inner pipe with the special structure described above is inserted into the outer pipe The upper and lower two-stage discharge ports can be injected into the drilled space evenly in the same amount. This method has the function of the conventional double pipe double packer method, and is suitable for soil properties from sandy soil to viscous soil. Reasonable injection improvement is possible, and This is a revolutionary injection technique that contributes to shortening of the period. At least one bag, usually a plurality of bags, is inserted into the shank of the outer tube, and a hard plastic is inserted into the ring-shaped gap between the inner and outer tubes. And an air packer (including a packer which expands with a fluid such as an inert gas such as air, water or nitrogen) or the like, and a hardening material supply passage is provided inside the outer tube. A rubber or air-type packer that the inner pipe is fastened to the outer pipe forms a space in the space adjacent to each other at a predetermined interval, and the hardening material injection port of the inner pipe is larger than the cross-sectional area of the inner pipe line. Formed at the injection port of the pores so that the total area is small, each bag is swelled by a hardening material such as cement mortar and fastened tightly to the wall surface of the drilled hole,
Due to the expansion of the bag body, the ground around the bag body is also compacted to become a packer body of a larger size than the substantially expanded bag body,
In order to prevent the chemical solution from penetrating beyond each bag, and to increase the length of one injection stage, even if discharge resistance occurs due to the collapse of the hole wall of the drilling space around the outer tube, the inner tube can be made thinner. Due to the fact that the hardening material is injected into the space from the injection port of the hole, the hardening material is stably discharged from the plurality of outer pipe outlets in a predetermined state, regardless of the change in the resistance pressure outside the pipe, and reliably. In a predetermined injection stage, the solid is homogeneously injected and permeated into the ground to form a long shaped object of a predetermined size in a predetermined large area.In each pressure space, if a pressure sensor is provided, the pressure It can be measured on the ground that the injection osmotic pressure of the hardening material in the space is acting reliably, and the sealing action of the bag body against the drilled hole wall and the hardening of the blowout from the bag type outlet Long-lasting injection into the ground of space with a stable amount of wood Permeability is performed by large size, in which the cylindrical structure of the long drilling of prevention or deep ground of liquefaction is formed in the ground has to be stably performed.

In FIG. 12, the number of bags provided in the outer tube is one in the upper and lower sets, but a plurality of sets may be provided, or at least one. That is, when the injection bag is short, one bag body is provided on the ground side, and a multistage discharge port is provided in the outer tube below the bag body, and a predetermined injection amount from each discharge port is provided from the multistage discharge port. 2
It can be injected more than once.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following is a description of embodiments of the invention of this application as embodiments of the present invention, with reference to FIGS. 1 to 7 and FIGS.

The same parts as those in the eighth and subsequent drawings are described using the same reference numerals.

The illustrated embodiment is a construction embodiment in which a hardening material is injected to prevent liquefaction of the ground. In the embodiment shown in FIGS.
Reference numeral 20 denotes a ground injection device that employs a predetermined stroke step-up method that forms the center of one aspect of the invention of the present application. The schematic configuration thereof is, as shown in FIGS. An inner tube 28 equipped with an outer tube 21 made of synthetic resin, a hard plastic or rubber packer 29 provided at a predetermined number of steps at a predetermined position in the axial direction with respect to the outer tube 21, and It consists of a plurality of bags 26 made of synthetic resin or the like provided at set intervals on the shank. The bottom of the tip of the outer tube 21 is blindly closed by the lid 27, and the tip of the tip is The upper and lower ends of the bag body 26 are fastened to the side surface of the outer tube 21 by ring bodies 24, 24 so as to be able to expand and contract.

A predetermined hardening material discharge port 25 is formed inside the bag 26, and a rubber sleeve 23 is formed on the outer surface of each discharge port 25 so as to cover them. Has been established.

The shank of the outer tube 21 is provided with bags 26, 26... At predetermined intervals (not necessarily at the same bite interval). A hardening material discharge port 25 is formed in a similar manner, and is provided on the outside thereof via a rubber sleeve 23 so as to be openable and closable as described above.

Also, as shown in FIG. 1, the outer tube 21 is connected to a set length through a turnbuckle type joint 22 so that the outer tube 21 has a predetermined length.

As described above, the injection device 20 does not fill the hole 8 with the sleeve grout 13 therein as in the conventional embodiment shown in FIG.
Each of the bag bodies 26 provided at a predetermined pitch is smoothly inserted into the borehole 8 of the ground in a state where the bag body 26 is folded or entangled with the side surface of the outer tube 21 and each of the pre-bored strata is formed. The bags 26 are set on the stage so as to correspond to each other.

The rubber or plastic packers 29, 29, which are installed at a predetermined pitch on the inner tube 28 inserted into the outer tube 21 between the bags 26, 26, are sprayed. Openings are formed in the ports 34, 34,..., And the hardening material 19 fed from a not-shown ground-pressure pump is described with reference to FIG.
As shown in FIG. 0, the hardening material 19 can be ejected at a constant predetermined amount for each step-up stage of a predetermined stroke regardless of a change in the state of the resistance pressure outside the inner tube 28. I have.

It is also possible to provide a known pressure sensor for the space 32 between the rubber or plastic packers 29 provided at a predetermined pitch inside the inner tube 28. A lead cable extends from the inner tube 28.

The tip of the inner tube 28 has a blind bolt 27 '
Are sealed and sealed.

An embodiment of the ground injection method in the injection apparatus 20 having the above-described structure will be described. As shown in FIG. 4, the hardening material is injected and penetrated into all stages at once. In a state where the sleeve grout 13 is not filled and interposed in a conventional manner with respect to the formed drilled hole 7 and each bag body 26 which is inserted and mounted on the outer tube 21 at a predetermined pitch is externally provided, smoothly to a predetermined depth. insert.

Then, the hardened material supply passage 18 inside the inner pipe 28 is passed through a pressure pump (not shown) from the ground.
When a predetermined hardening material 19 is supplied under pressure, the hardening material 19 is jetted from each of the injection ports 34 of the inner tube 28 to expand each of the bag bodies 26. The inner wall is brought into close contact with the hole wall from the inside to be brought into a tightened state, and the expansion force causes the surrounding ground to be compacted and fixed over time, thereby maintaining the insertion set posture in the inserted hole 8. .

The infusate for infiltration in this way is supplied through a pressure pump to a portion of the inner tube 28 where the sleeve grout 13 is not filled and filled with the sleeve grout 13 between the bags 26, 26.
A pressure accumulation state is maintained through the space 32 between
1 penetrates and penetrates into the hole wall of the drill hole 7 by the packer effect due to the bag body 26 being pressed and fixed to the drill hole 8 through the discharge port 25, and at this time, the hole wall of the drill hole 7 As shown in FIG. 4, the collapse 7 '
9 and 10, even if clogging or the like occurs in some parts of the inner pipe 28, the injection port 34 of the inner pipe 28 enters the inner pipe 28 regardless of the resistance pressure as shown in FIGS. A predetermined amount of hardening material is sprayed at a constant rate in accordance with the pressure (pump pressure) of the injection port, and a predetermined amount penetrates into the periphery, and the entire injection depth from the discharge port of the outer tube 21 is increased. As a result, the hardening material is uniformly injected and penetrated, and a large amount of columnar shaped body having a predetermined large size can be formed in the ground as designed by continuing to inject a large amount in a long time.

11, 12, and 13, the embodiment of the basic construction is additionally shown. As shown in FIG. 11, as shown in FIG. An inner tube is inserted into the bag 26 inserted every time, etc., and cement milk or a hardening material 26 ′ whose gel time is instantaneously set or long-set.
And the gap between the ground disturbed by the drilling 7 and the outer pipe 21 is tightly consolidated 26 ′, and the ground constrained every two meters or the like by the packer 26 as one stage is formed by the inner pipe 28 as described above. The inner tube 28 having a simple structure is inserted into the outer tube 21 so that the hardening material can be injected into the drilled space from the two upper and lower discharge ports in a uniform amount, and the embodiment is further sequentially described with reference to FIG. To explain, as shown in (a), a drilled hole 7 is formed in the ground with a casing for building an injection outer tube, and as shown in (b), an injection outer tube 21 with a bag 26 inserted therein is built.
As shown in (c), the inner tube 28 is inserted, and the hardening material is filled and injected into the bag body 26 to form a strong packer of the bag body 26 to strengthen the consolidation 26 'of the surrounding ground. As shown, the inner tube 28 is inserted into the outer tube 21 to inject the permeable hardening material.

As a practical example of the design mode of the method, as shown in FIGS. 11 to 13, the injection pipes are arranged in a square with a buried interval P = 2 mx 2 m, the injection speed f = 30 l / min, and the injection pipe 1 Improved flat area per hole Ap = 2mx2m = 4m
^{2 The} amount of improved soil per stage (m ³ ) is V = 2 m (improved height) × ⁴ m ² = 16 m ³ , the injection amount per stage (kl) Q = Vx (0.35 to 0.40) = 50.6 ~ 6. 4 kl injection rate; 0.35 to 0.40 injection time per stage t ₁ = 6 kl ÷ 0.03 kl / min = 200 min = 3.3 hours (injection continuation time) Injection filling amount of packer bag (l ) A large amount of injection can be performed over a long time with q = 60 l.

When the hardening material of the bag 26 is pressed and expanded, the surrounding ground is strengthened with time and becomes a packer substantially larger in size than the bag 26, and injected over each packer. The liquid does not deviate, and FIGS.
As shown in (d), it is injected and permeated into the stage of the design stratum and solidifies.

The space between the pouches 26, 26 is not filled with seal grout, and even if the drilling collapses, the hardened material reaches a predetermined depth through the special inner pipe through the outer pipe. At this time, a predetermined amount is injected.

This is an important point of the invention of this application.

Accordingly, the sleeve grout 13 is not interposed and filled in the hole 7 formed in the ground of the ground as in the conventional mode due to the interposition of the inflatable packer provided in the outer tube. The hardened material ejected from the pipe 28 is shown in FIGS.
As shown in the data shown in the above, it is possible to inject and infiltrate into the stratum ground of all stages in a uniform state without fail, and it is possible to form a large-sized molded body in the ground as designed.

As shown in FIG. 2, the outlet of the outer tube 21 is provided at the upper and lower bags 2 as shown in FIG.
A plurality may be provided between the upper and lower bags 26, 26 in the embodiment shown in FIG.

In the process, the outer pipe 21 and the inner pipe 2
The pressure accumulation state of the space 32 formed between the packers 29 adjacent to each other in the gap portion of the ring of No. 8 is detected by a pressure sensor (if installed) and accumulated in a measuring device (not shown) on the ground, that is, It is detected that the injection is being performed.

The state of injection of the hardening material in the space 32 is confirmed, and depending on the pressure measurement data, the tightness of each rubber packer 29 to the inner wall of the outer tube 21 is ensured to ensure the ejection of the hardening material as designed. You can do it.

The backflow of the hardening material from the hardening material discharge port 25 of the outer tube 21 can be reliably prevented by the sleeve 23.

In this way, as shown in FIG. 5, the liquefaction-preventing construction can be performed by inserting and setting the injection device 20 in the ground crossing the vertical direction or the diagonal direction.

Further, as a design change aspect, it is a matter of course that the packer can be not only a rubber packer but also an air packer.

For example, reference numeral 28 'in FIG. 6 denotes an inner tube injection portion. The inner tube 28' is arranged at a predetermined pitch in the axial direction with air packers 29 ', 29'... And air or gas (for example, nitrogen gas).
The working flow path 30 ′ for liquid such as water or water and the flow path 40 for injection liquid are double pipes or parallel (if there are two injection pipe flow paths,
The air discharge port 30 ″ becomes a triple pipe or three parallel pipes)
A fluid is injected into the space 29 ″ through the space, and the air packers 29 ′ and 29 ′ made of a rubber packer are inflated and pressed against the inner wall of the outer tube 21. The water is injected into the ground from the injection ports 25, 25 of the outer pipe 21 through the pipe 32. The operation and effect are substantially the same as those of the above embodiment.

A flexible inner tube is used as a part of the injection portion of the inner tube 28 shown in FIG. 6 or a flexible tube at a predetermined interval to form a flexible inner tube even if the outer tube 21 is bent by earth pressure. Can be easily inserted.

The flow path of the infusate or the fluid for operating the packer up to the inner tube injecting section may be a flexible hose such as a double tube or a parallel tube.

In practicing the invention of this application, the inner tube may be injected while the injection stage is shifted upward as shown in FIG. 2, or as shown in FIG. Can be injected all at once, or the injection stage of all injection depths can be injected at once with the inner tube fixed.

[0053]

As described above, according to the invention of this application, in the construction work for preventing liquefaction of soft ground and the reinforcement work for excavation of the foundation of a building, the hardening by the double pipe double packer system is basically performed in the ground. To perform the material injection work, at least one or multiple stages of bags in the axial direction are inserted into the shank of the outer tube, the inner tube is inserted into the outer tube, and the hardened material such as cement milk is inserted into the bag. To form a consolidated body by inflating the bag body and tightly fixing it to the drill hole, so that a number of outer tubes are provided on the target ground, and each bag body is fixed to the ground by solidification of the consolidated liquid After that, when the hardening material is injected and penetrated into the ground through the drilled space from the hardening material discharge port pierced between the bags of the outer tube, and the construction is performed, at least one outer tube is provided between the bags. Of the inner tube between the packers provided in multiple stages. With the injection device in which the material injection port is bored, the hardening material discharge port and the hardening material injection port are separated from each other by an injection pipe packer provided integrally and communicated with each other in the same space. Even if resistance pressure is generated at the hardened material discharge port of the outer pipe due to the collapse of the drill hole, etc., or even if resistance pressure is generated due to the difference in the soil layer, the hardened material is injected into the inner pipe. A predetermined amount of hardened material is always ejected from the outlet, and even if the length of one injection stage is increased and the discharge amount per minute per stage is increased, the predetermined amount is uniformly injected at a predetermined depth and injected for a long time per stage It is possible to continuously inject a large amount of chemical solution, and therefore, an excellent effect that a large-sized, super-long, large-diameter cylindrical shaped object as designed can be reliably formed in the ground. Is played.

Also, an injection liquid such as cement milk is pressed into a plurality of bags provided on the shank of the outer tube to expand the bags,
By compacting the surrounding ground, an extremely strong packer effect is surely formed.

For this reason, it is no longer necessary to form a seal around the outer tube with the sleeve grout, and the hardening material permeates the surrounding ground in the entire drilling space surrounded by the pair of upper and lower bags.

Assuming that the term “one stage” is used as a unit section in the axial direction of the injection tube for injection at a time,
Since the permeation area of the hardening material source per stage is very large, even if the discharge amount per minute is increased, injection can be performed at a low pressure, and the excellent effect that permeation injection between soil particles becomes possible. Is played.

Further, even if the injection is continued for a long time because the hardening material can be permeated in a wide area at once, the permeation area of the injection source is large, so that the permeation source is not closed with the gelled material. There is also an effect that there is no.

Also, since the packer is widely compacted around the packer due to the inflating effect of the bag, a packer effect larger than that of the actual bag is formed. There is also an effect that it is difficult to escape into space.

Therefore, even if the hardening material is continuously pressed in for a long time, an excellent effect is obtained in which the hardening material can uniformly penetrate and solidify the ground over a wide area without escaping out of the system.

Accordingly, an excellent effect is obtained in that the hardening material can be uniformly injected into all stages at once, and a molded object as designed can be formed.

Further, since the total area of the injection ports of the inner pipe in one stage is formed to have a smaller diameter than the cross-sectional area of the inner pipe, as shown in FIGS.
(kg / cm ² or more), it is ensured that a predetermined amount of hardening material corresponding to the discharge port diameter is discharged from the discharge port of the inner pipe even if the drilling hole collapses and the resistance pressure differs, resulting in In addition, an excellent effect is achieved in that a shaped body in the ground as designed can be formed over all stages.

When pressure sensors are provided in the pressure spaces between the packers inserted at a predetermined pitch in the axial direction in the ring-shaped gap between the outer tube and the inner tube, the pressure of the hardened material in each of the pressure spaces is increased. In this case, since it is possible to detect through a lead cable, the state of accumulating and filling the hardening material in the pressure space is detected, and it is possible to confirm that the hardening material is reliably injected into the ground. Is played.

In addition, since the packing operation is excellent, it is possible to adopt a mode in which the above-mentioned injection device can be intensively shifted for each block in a wide area of the ground to perform the injection.

When the ground is a large area to be constructed, the pouring device is concentrated for each block and the pouring is performed simultaneously or at different times to perform the pouring according to the characteristics of each area of the ground. The construction can be performed, the construction ability is good, and the excellent effect that the construction period can be changed as designed can be achieved.

Further, since the sleeve grout is not interposed, the resistance pressure against the discharge port of the outer tube changes variously, or the discharge resistance changes due to the collapse of the hole wall of the drilled hole. Also, even if the front of some of the discharge ports is buried by the collapse phenomenon, a certain amount of hardening material that corresponds to the pump pressure and the diameter of the discharge port is guaranteed from the discharge port of the discharge nozzle of the inner tube. Through the drilling space, a predetermined amount of the hardening material in the ground is infiltrated and injected over the entire length of the injection stage, and therefore, the construction of the large-sized long shaped ground in the ground as designed is performed as designed. An excellent effect is achieved.

The ground improvement obtained in this way can not only prevent the liquefaction phenomenon but also sufficiently exert the reinforcing effect in the excavation work of various grounds, and the reinforcing material effect can be obtained in the construction work such as starting the shield. It has an excellent effect that it can exert a great effect on water stoppage and reinforcement during tunnel excavation. .

Further, since the hardening material discharge from the discharge port of the outer tube and the discharge port of the inner tube are mutually connected to the pressure space formed between the packers, the discharge port of one outer tube is Even if it becomes a closed state or clogging resistance increases, a certain amount of hardening material is guaranteed to be ejected from the injection port of the inner pipe, and the excellent effect of infiltration into the ground through the drilled space is achieved. Is played.

Also, a plurality of inner pipes for injecting liquid to be inserted into the outer pipe are provided with a small diameter, and a plurality of the inner pipes are connected to each other to consolidate the ground with an injecting liquid having a gelation time arbitrarily adjusted through a two-liquid injecting liquid. The excellent effect that it can also be performed is produced.

From this point as well, an excellent effect is achieved in that the formation of an artificial body in the ground of a large size and a long length with respect to the ground of the ground is performed as planned.

Further, since the ground injection device of the present invention can be intensively performed for each block of the ground after consolidation through the expansion of each bag body, a predetermined ground improvement for the ground in a large area area can be performed. An excellent effect is achieved in that construction can be performed efficiently.

Since the hardening material in the vertical and oblique directions can be injected into all the stages of the ground at once, the construction efficiency is high and the management is difficult, and the construction time can be shortened with extremely high efficiency. Excellent effects are achieved.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional side view of a ground injection device of the present invention.

FIG. 2 is a partial enlarged sectional view of a main part.

FIG. 3 is an enlarged half sectional side view of an outer tube.

FIG. 4 is a cross-sectional view for explaining a procedure for installing an injection device inserted into a hole;

FIG. 5 is a schematic cross-sectional view related to a liquefaction prevention construction technique in a construction mode.

FIG. 6 is an exploded sectional view of another embodiment of the inner tube, and (a) and (b) are partial longitudinal sectional views of the exploded connection.

FIG. 7 is a schematic cross-sectional view of a double-pipe double-packer injection via a sleeve grout provided with a bag body according to the prior art.

FIG. 8 is a sectional view showing the construction of an injection device for drilling a sleeve grout according to the related art.

FIG. 9 is a graph of the transmission of the resistance pressure and the flow rate from the injection port of the fine hole at a constant nozzle according to FIG. 8;

FIG. 10 is a flow chart showing the resistance pressure and the flow rate from the injection port when the size of the injection port of the pore is changed.

FIG. 11 is a schematic side sectional view of a basic embodiment of the present invention.

FIG. 12 is a schematic side sectional view of the same construction order, (a) is a schematic side sectional view of a casing drilling hole, (b) is a schematic side sectional view including an outer tube, and (c) is ground consolidation by a bag body. FIG. 3 is a schematic side sectional view of reinforcement, and (d) is a schematic side view of injection of a permeable hardening material.

FIG. 13 is a schematic plan sectional view of FIG. 11;

[Explanation of symbols]

 26 bag body 21 outer tube 25 hardening material discharge port 34 hardening material injection port 28 inner tube 32 space 29 packer 20 ground injection device 7 drilling

Claims (4)

[Claims] 1. An axially double-staged hardening material discharge port is formed in a shank of an outer tube in which an inflatable bag body made of a hardening material is fitted, and a hardening comprising similarly axially double-staged pores therein. An inner pipe in which a material ejection port is bored and a plurality of stages of packers are interposed across the ejection port is inserted into the outer pipe, and the packers are arranged in a space 12 between the inner and outer pipes in a plurality of axial directions. In the ground standing apparatus formed with steps, at least one bag is attached to the shank of the outer tube, and at least one hardening material discharge port and a plurality of packers of the inner tube are provided below the bag of the outer tube. And at least one hardening material ejection port is formed between the two, and the hardening material ejection port and the hardening material ejection port are connected to each other in the same axially separated space. Ground injection equipment. 2. An injection device having an inner pipe inserted into an outer pipe provided with a plurality of discharge ports to inject hardening material into the ground, wherein the inner pipe has at least three fluid-expanded fluids. A ground injection device wherein a hardening material is simultaneously ejected from a plurality of packers and at least one injection port located between the packers. 3. The soil injection device according to claim 1, wherein a pressure sensor faces a space formed between the packers. 4. A plurality of steps formed in a shank of the outer tube by inserting an outer tube having a plurality of hardening material discharge ports into which an inflatable bag body made of a hardening material is mounted and inserted into a hole formed in the ground. In the ground injection method of injecting the hardening material into the ground from the hardening material discharge port, the bag body is inflated with a hardening agent so as to be fixed to the hole wall of the drilled hole, and a plurality of injection ports are provided. A method for injecting a hardening material from an inner pipe having the same so as to permeate the ground through a discharge port of the outer pipe.