JP2794319B2 - Chemical injection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a chemical liquid injector for mainly injecting a chemical liquid into a sandy ground or the like while applying vibration to a chemical liquid injection area.

[Conventional technology]

The chemical solution injection method is a type of soil improvement, and is a method for injecting a solidifying agent into a target ground and consolidating the same, thereby increasing the strength of the ground or reducing the water permeability of the ground. In recent years, there has been a remarkable development in the chemical solution injection method and its device.

In recent years, general-purpose construction methods include a strainer injection method, a solenoid method, and other various methods. The strainer injection method is a method in which a strainer injection pipe is installed in a hole drilled by a boring machine, and an injection material is discharged and injected in a ground horizontal direction from a number of injection holes formed in the strainer injection pipe. It is. In addition, with the above-mentioned Soletanesh method, an outer tube in which injection holes are formed at regular intervals and a rubber sleeve is wrapped around the injection hole is installed in a bored hole, and the outer tube is provided in the outer tube. Insert the inner tube with rubber packer up and down in the depth direction,
This is a method of injecting a chemical solution such that the gel time is several minutes or tens of minutes while sequentially changing the ground to be injected.

On the other hand, there is a vibration compaction method as a ground improvement method for increasing the density of the sandy ground mainly for preventing liquefaction of the sandy ground. The vibration compaction method is based on the principle that compaction of loose sand ground can increase the ground density most effectively by applying vibration. Examples of the method include a vibro flotation method and a vibro rod method. And so on.

The vibro flotation method is to penetrate a pipe called a vibro flott that causes horizontal vibration by rotation of an eccentric load to a predetermined depth of the ground by using both water jet and horizontal vibration, and after penetration, gravel, crushed stone, etc. from around the flot. And vibrating the ground via the aggregate to compact the ground. On the other hand, the vibrating rod method is a method of compacting a sandy ground by repeatedly intruding and lifting a press-fit rod having a specially processed tip into the ground using a vibrating pile driving machine or the like.

About the compaction effect by the vibration compaction method etc.
A description will be given based on the drawings.

FIG. 3 is a view showing the effect of soil improvement on a loose sandy ground by the above-mentioned vibration compaction method. As is clear from FIG. 3, before the improvement, the ground with the N value ≦ 10 shown in the shaded area was compacted by vibration, and it was found that the N value was improved to about 20 to 40 after the improvement. Is done. In the case of sandy ground in this way, by vibrating the ground, the compaction can be performed remarkably because the skeletal structure of the soil is destroyed by the vibration and the liquefaction phenomenon when there is groundwater This is thought to cause groundwater to erupt to the surface.

On the other hand, it is generally known that a fluid such as a grout material has the same effect as when a vibration is applied to the grout material. For example, in the case of placing concrete, vibration is usually given by a vibrator.

By the way, there are various types of prior disclosure techniques using vibration for ground improvement. For example, JP-A-56-1317
No. 09 discloses an apparatus in which an air vertical vibrator or a horizontal vibrator is mounted near an auger head in order to uniformly and sufficiently mix and mix soil on a soft ground and a chemical solution. Further, in Japanese Patent Application Laid-Open No. 57-187417, a nozzle provided on an element is inserted into an sludge layer while vertically vibrating the element, and the vibration is transmitted to the sludge layer via the element. A chemical liquid injection method is disclosed in which a solidifying agent is discharged more to vibrate and mix the sludge and the solidifying agent.

[Problems to be solved by the invention]

Usually, when grouting cement milk, cement pentonite milk, etc. on sandy ground or gravel ground, etc., penetration injection cannot be expected for the reasons described below, so splitting injection or pulse injection at a large injection pressure is required. Do. This is because when a fluid having particles larger than the gap flows into the gap in the sandy ground, the particles close the gap between the grains in the ground, and are composed of particles smaller than the gap in the sandy ground. Even if the flowing fluid flows,
If the infiltration proceeds to a certain distance, the flow velocity will decrease, the injected material will settle between the soil particles and block the ground gap, or the particles of the injected material will gather in the gap between the ground particles to form an arch, This is for closing the gap. Conventionally, there is no disclosed technology that has solved the above-mentioned problem.

In addition, various types of known techniques using vibration in the conventional ground improvement method have been disclosed, but all of these techniques use vibration for mixing a chemical solution and soft soil. This is the range of applied technology of mixing using a vibrator in concrete casting, and does not utilize vibration to solve the above-described problems in the case of infiltration or pulsation in chemical injection.

Accordingly, an object of the present invention is to provide a penetrating injection or a vein injection without mainly closing a gap between soil particles by a injected chemical solution when the chemical solution is injected into a sandy / gravel ground, thereby improving the improved ground. It is an object of the present invention to provide a liquid injector capable of obtaining a liquid medicine.

[Means for solving the problem]

The drug solution injection device of the present invention that has solved the above-mentioned problems is, as a single-tube type device, an injection tube installed in the ground, and a position that is installed in the injection tube and deviated from the axis of the injection tube. A vibrator having a center of gravity, a rotational driving means installed on the ground for rotating the vibrator around the axis of the injection pipe, and a rotational force transmitting means connecting the vibrator and the rotational driving means, further comprising: The rotating shaft integrated with the vibrator is held in contact with the inner surface of the injection tube.

Further, as a double-pipe type apparatus, an injection pipe consisting of a concentric outer pipe and an inner pipe installed in the ground, and a position installed in the injection inner pipe and deviated from the axis of the injection pipe. A vibrator having a center of gravity, a rotational drive unit installed on the ground that rotates the vibrator around the axis of the injection inner tube, and a rotational force transmitting unit that connects the vibrator and the rotational drive unit.
Further, the rotating shaft integrated with the vibrator is held in contact with the inner surface of the injection inner tube, and the injection inner tube is in contact with the inner surface of the injection outer tube. .

[Action]

In the present invention, in particular, at the time of injecting a chemical solution into a sandy ground, vibration is applied to the target ground by a vibrator incorporated in the chemical solution injection means or by a vibrator separately and independently penetrated into the target ground. Since the chemical solution is injected while the chemical solution is being injected, the chemical solution can be injected while destroying the skeleton structure of the soil particles. Therefore, it is possible to prevent the particles of the injection material from closing the gap between the particles of the ground, and to prevent the particles of the injection material from gathering in the gap between the particles of the ground to form an arch and closing the gap. it can. As described above, when vibration is applied to the ground, the ground is compacted, but this phenomenon means, in other words, an increase in the N value, that is, a decrease in the porosity. If not, it is considered that a space is generated in the vibrating part. The present invention
Vibration is applied locally, and the chemical solution is injected into that part.Therefore, the upper layer sand does not fall, and voids are created at the same time as the chemical liquid is injected into that part, which is effective and effective The drug solution is injected over a wide area.

In addition, as a single tube type device for the injection,
A vibrator having a center of gravity at a position deviated from the axis of the injection pipe in an injection pipe installed in the ground, a rotation drive means installed on the ground for rotating the vibrator around the axis of the injection pipe, and the vibration And a rotational force transmitting means for connecting the rotor and the rotational drive means. Therefore, the rotational force of the rotational driving means installed on the ground is transmitted to the vibrator by the rotational force transmitting means. Since the vibrator has its center of gravity at a position deviated from the axis of rotation, the vibrator emits vibration by rotation, and the vibration is generated by the rotation shaft integrated with the vibrator on the inner surface of the injection pipe. Is held in contact with and is transmitted to the ground to be injected via the rotation holding portion.

On the other hand, in the case of the double tube system, the vibrating structure is the same as the single tube system, but the rotating shaft integrated with the vibrator is held in contact with the inner surface of the injection inner tube, and Since the inner tube for injection is in contact with the inner surface of the outer tube for injection, the vibration by the vibrator is transmitted to the inner tube for injection via the rotation holding portion, and further the outer tube for injection, Is transmitted to the ground to be injected.

[Specific configuration of the invention]

 Hereinafter, the present invention will be described in detail with reference to the drawings using specific examples.

FIG. 1 is a longitudinal sectional view of a main part of a chemical liquid injection device according to the present invention, and FIG. 2 shows a construction order of a chemical liquid injection method according to the present invention.

First, the apparatus of the present invention shown in FIG. 1 will be described in detail.

This specific example has a double pipe structure, and includes an outer injection tube 2 and an inner injection tube 1. As will be described later, the injection outer tube 2 is a long tube built in the ground hole, and a plurality of injection holes 2a, 2a,... A rubber sleeve 3 is provided on the tube 2 so as to cover. The rubber sleeve 3 functions as a valve when injecting the drug solution and prevents slime from flowing backward when the injection of the drug solution is stopped. The rubber sleeve 3 swells outward due to the injection pressure of the injected drug solution, and the swelling causes the outer tube 2 to inject. And a chemical solution is injected into the ground through the gap.

Note that the chemical solution injection portions are provided at regular intervals in the longitudinal direction of the outer injection tube 2, for example, at intervals of about 30 cm. Also,
The connection between the outer injection tubes 2 and 2 is made by screwing the end of one outer injection tube 2 into the end of the other outer injection tube 2 at the joint 4.

On the other hand, a double packer type inner injection tube 1 is inserted into the inner space of the outer injection tube 2. In the injection tube 1,
The discharge holes 10b, 10b ... communicating with the space 6 with the outer injection tube 2 are formed, and a second packer body 16 for sealing the space 6 is provided below the discharge holes 10b, 10b ... , And above the discharge holes 10b, 10b,.
A first packer body 10 for sealing the first packer is formed.
The packer bodies 10 and 16 are both formed to have an outer diameter that is substantially in contact with the inner surface of the injection outer tube 2, and three concave grooves 10a and 10b are formed around the periphery thereof in the depth direction of the ground. An O-ring 7 having a circular cross section is fitted into the concave grooves 10a and 10b, and the space 6 is sealed by bringing the O-ring 7 into contact with the inner surface of the outer tube 2 for injection.

On the other hand, a vibrator 13 constituting a vibrator according to the gist of the present invention is provided in the injection inner tube 1 with the second packer body.
It is provided above 16. The vibrator 13 is accommodated in a vibrator chamber 14 formed in the inner injection pipe 1 and has rotating shafts 13a and 13b extending vertically in the ground depth. The upper rotation shaft 13a is connected to the rotation wire 11 via a rotation joint 12, and further connected to a rotation motor (not shown) outside the injection inner tube 1. The lower rotating shaft 13b is supported by a bearing device 17. The rotating shaft 13a is provided to penetrate the weir wall 8 between the slider chamber 14 and the liquid path 5, and has a concave groove 10c formed at a contact portion of the weir wall 8 with the rotating shaft 5a. O fitted to
The ring 15 is sealed so that the medicine does not flow into the vibrator chamber 14. The center of rotation of the rotating shafts 13a and 13b and the position of the center of gravity of the vibrator 13 are eccentric.

Therefore, the rotation transmitted by the rotation motor (not shown) includes the rotation wire 11, the rotation joint 12, and the rotation shaft 13a.
Is transmitted to the vibrator 13. The vibrator 13
Since there is a deviation between the rotation axis and the position of its own center of gravity, vibration is caused by the rotation. This vibration is transmitted from the first packer 10 and the second packer 16 which are the contact portions with the outer filling tube 2 to the outer filling tube 2 and further transmitted into the ground.

Next, a specific example of a drug solution injection method using the device of the present invention will be described.

As shown in FIG. 2 (a), a hole is formed in a target soft ground using a casing tube 20 for protecting a hole wall using a boring drill (not shown). At this time, if there is no possibility that the hole wall collapses, the illustrated casing 20 can be omitted. Next, when drilling is completed, as shown in FIG. 2 (b), an outer pouring tube 2 is erected in the hole, and thereafter, for example, a bentonite-based material is inserted between the outer pouring tube 2 and the ground. Sleeve grout
Fill 21. The sleeve grout 21 serves to prevent the chemical solution from escaping to a location other than the scheduled injection location. After filling the sleeve grout 21, the casing 20 is pulled out while the sleeve grout 21 is not completely consolidated. Thereafter, when the sleeve grout 21 is completely consolidated, the inner tube for injection 1 according to the present invention is inserted into the outer tube for injection 2 to inject a chemical solution. As described above, the injection outer tube 2 is provided with injection holes 2a, 2a,... At regular intervals in the depth direction of the ground, and a chemical solution discharge hole 10 at an intermediate portion between the packers 10, 16 of the injection inner tube 1.
The chemical solution is injected while the b, 10b... portions are aligned with the injection holes 2a, 2a. The chemical solution injection is sequentially performed while moving on the ground to be injected, whereby the chemical solution is injected over the entire area in the depth direction of the ground. However, when there is groundwater, liquefaction occurs due to vibration, and the groundwater tends to squirt above the ground. Therefore, it is desirable to perform the processing in order from the deepest part of the ground in view of the discharge of the groundwater.

In addition, at the time of injecting a chemical, it is possible to inject the chemical into an injection region that cannot be reached by ordinary injection only after the injection of the chemical while destroying the skeleton structure of the ground by applying vibration. Therefore, it is desirable to apply vibration simultaneously with the start of the injection of the chemical solution into the ground.

By the way, when the joint 4 of the injection outer tube 2 is made flexible, the vibration can be locally transmitted to the ground without being transmitted to the adjacent injection outer tube 2, and the vibration can be transmitted to the ground at the injection end point. The effect can be eliminated.

On the other hand, all of the liquid medicine injection methods described above are cases in which a vibrator is integrally provided in a tube for injecting the liquid medicine,
Vibration may be applied to the ground area where the chemical solution is injected separately from the injection of the chemical solution (hereinafter, referred to as an indirect method). For example, as shown in FIG. 4, in the strainer injection method, boring is performed by a drill having a vibrator 31 at the tip of a rod 33 in the vicinity of a location where the strainer injection pipe 30 is inserted. By bringing the vibrator 31 at the tip of the rod 33 close to the ground area where the chemical solution is injected by the strainer injection, and simultaneously with the injection of the chemical solution, the vibrator 31 is vibrated by the rotary motor 32 to apply vibration to the surrounding ground. , Can reinforce the spread of the chemical solution. Since the effective vibration transmission area of the vibrator 31 is considered to be within about 50 to 100 cm, the injection portion of the strainer injection pipe 30 and the vibrator 31
Is preferably about 50 cm.

In addition, in the case of conventional chemical injection, in the case of sandy soil, a suspension having poor permeability (for example, cement-based grout) cannot be used as a grout material. While destroying the given skeletal structure,
Since the injection of the chemical solution is performed, the suspension-type grout can be used, and a high-strength solidified body can be obtained, which is economical. In addition, solution-type chemicals,
For example, a water glass-based chemical can naturally be used.

In addition, the chemical injection capacity of the conventional sandy soil depends on the injection pressure.
At 6 kg / cm ² , it was about 8 to 10 / min. However, according to the present invention, the injection pressure can be set high because the movement of the groundwater to be replaced with the chemical solution is facilitated.
At ~ 10 kg / cm ^2, it is possible to inject a drug solution at 10-15 / min.

Furthermore, it has been found that soft ground obtained by improving the ground by vibration compaction of sandy soil from past examples is less likely to liquefy during an earthquake as a result of the increased density of the ground. According to the chemical liquid injection method, the density of the surrounding ground can be increased by vibration, and the groundwater is discharged upward by simultaneously injecting the chemical into the gap created at that time, thereby discharging the groundwater. Since the ground is formed, the effect of preventing the liquefaction phenomenon can be exerted.

By the way, the vibration frequency of the vibrator is preferably higher as the particle size is smaller, so that the most effective frequency band can be appropriately selected depending on the particle size of the ground particles. It is desirable to have a frequency band of ~ 15000 vpm so that the frequency can be set arbitrarily. Moreover, what is marketed as a concrete vibrator can also be used as a vibrator. In this case as well, the frequency in the range of 7000 to 15000 vpm can be selected by the vibrator to be selected in the same manner, and the most effective frequency band may be selected according to the ground. In addition, by adjusting the intensity of vibration, the vibration position, and the injection pressure, it is also possible to limit the chemical solution injection range.

In applying the apparatus of the present invention, the effective vibration transmission area of the vibrator is considered to be within about 50 to 100 cm. Therefore, it is desirable to determine the boring position with a design effective diameter of 50 cm.

〔The invention's effect〕

As described in detail above, according to the present invention, when injecting a chemical solution into a soft sandy ground or the like, the gap between the soil particles is not blocked by the injected chemical solution, and it is possible to effectively perform infiltration and vein injection. As a result, a high quality improved ground can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a chemical liquid injection device according to the present invention, FIG. 2 is a view showing a specific example of a chemical liquid injection method according to the present invention, and FIG. 3 shows the effect of compaction by the vibration compaction method. FIG. 4 is a view showing an indirect method according to the chemical solution injection method of the present invention. 1 ... Injection inner tube, 2 ... Injection outer tube, 3 ... Rubber sleeve, 4 ... Joint, 5 ... Liquid channel, 6 ... Space, 7 ...
... O-ring, 8 ... Weir wall, 10 ... First packer body, 11 ...
... Rotating wire, 12 ... Rotating joint, 13 ... Vibrator, 14 ...
... vibrator chamber, 15 ... O-ring, 16 ... second packer body,
17 …… Bearing

Claims (2)

(57) [Claims] 1. An injection pipe installed in the ground, a vibrator installed in the injection pipe and having a center of gravity at a position deviated from the axis of the injection pipe, and the vibrator mounted on the axis of the injection pipe. A rotary drive unit installed on the ground for rotating the rotary unit, and a rotary force transmitting unit connecting the vibrator and the rotary drive unit; and a rotary shaft integrated with the vibrator contacts the inner surface of the injection pipe. A liquid injector is characterized by being held as a liquid. 2. An injection pipe comprising a concentric outer pipe and an inner pipe installed in the ground, and a vibrator installed in the inner pipe and having a center of gravity at a position deviated from the axis of the injection pipe. When,
A rotary drive unit installed on the ground for rotating the vibrator around the axis of the injection tube; and a rotational force transmitting unit connecting the vibrator and the rotary drive unit, and further integrated with the vibrator. The liquid injection device is characterized in that the rotation shaft thus set is held in contact with the inner surface of the injection inner tube, and the injection inner tube is in contact with the inner surface of the injection outer tube.