JPS5952016A - Method and apparatus for injection work into ground - Google Patents

Abstract

PURPOSE:To ensure the mixing and reaction of water glass with carbon dioxide by a method in which the flow rate of water glass aqueous solution and the pressure value and flow rate of carbon dioxide are transmitted to a ratio setter, and the valve of the carbon dioxide flow line is controlled so as to keep the ratio of them constant. CONSTITUTION:A water glass aqueous solution is sent from the path of the outer tube 15 of a multiple injection tube 3 penetrated into soft ground, and carbon dioxide as a reactant is sent out from the path of the inner tube 16 of the tube 3. They are joined in the tip portion of the injection tube and then injected from an outlet 21 into the ground. In this case, the flow rate value of the water glass aqueous solution, which is sent through the pipeline 13 from a storage tank 1 to the injection tube 3 by a pump 6, is detected by a flow rate detector 7 and transmitted to a ratio setter. The pressure and flow rate of the carbon dioxide sent to the injection tube 3 from a bomb 2 are detected by a pressure detector 10 and a flowmeter 9 and transmitted to a setter 4. In the setter 4, the flow rate of the carbon dioxide is calculated according to the gas pressure, and the flow rate of the gas is controlled so that a given ratio to the water glass aqueous solution is kept.

Description

Detailed Description of the Invention The present invention involves injecting a water glass-based solidification chemical into a soft yet leaky bed (hereinafter referred to as the "ground") to solidify and break the ground.
The present invention relates to a ground injection method and device for water stoppage (hereinafter simply referred to as consolidation), and more particularly to a ground injection method and device using carbon dioxide gas as a reactant for water glass.

Conventionally, when consolidating the ground, aqueous water glass solution and its hardening agent have been mixed and injected in a liquid-liquid or solid-liquid state, but a method using carbon dioxide gas as the hardening agent has been proposed. As a result, it became necessary to mix and inject the chemical liquid in a gas-liquid state, but this has not yet been put to practical use. The reason for this is that when carbon dioxide gas is combined with a water glass aqueous solution and injected, the ratio (absolute flow, not the volumetric flow rate) of the two (the relationship between the amount of alkali in the water glass and the equivalent amount of carbon dioxide) must not be within a certain range. This is because it is impossible to cause a predetermined solidification phenomenon.

A particularly difficult point is that in the known liquid-liquid mixing method, the combined flow rates of the water glass aqueous solution and the reactant aqueous solution are almost their absolute amounts, whereas the combined flow rates of carbon dioxide gas are constant. However, if the injection pressure changes, the absolute amount will fluctuate by a large amount [1], and therefore the ratio with water glass will not be constant, causing variations in the gelation phenomenon produced by this reaction or failure to solidify. It had a defect.

An object of the present invention is to provide a ground injection method and device that controls and injects the absolute amount of carbon dioxide gas to be mixed with the amount of water glass at a predetermined ratio to form a uniform solid body. .

In order to achieve the above-mentioned object, according to the construction method of the present invention, a water glass aqueous solution from a water glass distribution system and carbon dioxide from a carbon dioxide distribution system are mixed at a desired constant ratio in a mixing section and then poured into the ground. In the ground injection method, the flow rate value of the water glass aqueous solution is transmitted from the water glass flow system to the ratio setting section, and the pressure value of the carbon dioxide is transmitted to the water glass flow system, the carbon dioxide flow system, or a mixture. The flow rate ratio of the water glass aqueous solution and carbon dioxide is determined by the ratio setting part in response to an instruction from the ratio setting part, and the carbon dioxide is sent so as to maintain a constant ratio. Adjustment of the flow rate of carbon dioxide in the flow system 1~, thereby allowing the water glass aqueous solution and carbon dioxide to be mixed at a desired constant ratio in the mixing section; According to the above, a mixing section for mixing a water glass aqueous solution and carbon dioxide, a water glass flow system communicating with this 61 and the joining section, a carbon dioxide flow system communicating with the mixing section, and the water glass A water glass flow rate detector installed in the flow system, a carbon dioxide pressure value i1'l Rg installed in the mixing section, the water glass flow system or the carbon monoxide flow system, and the carbon dioxide flow system -a carbon 7 oxide flow rate regulating valve installed in a carbon dioxide flow rate regulating valve; and a ratio setting device connected to the water glass flow rate detector, -carbon oxide pressure detector and carbon dioxide flow regulating valve, respectively; receives information on the water glass flow rate value and carbon dioxide pressure value from the water glass flow rate detector and carbon dioxide pressure detector, respectively, and based on this information, outputs an instruction to the carbon dioxide flow regulating valve, and the carbon dioxide The carbon flow rate adjustment valve adjusts the flow rate of carbon dioxide so that the flow rate ratio of the water glass aqueous solution and carbon dioxide is maintained at a constant ratio determined by the ratio setting device, so that the water glass aqueous solution and carbon dioxide flow into the mixing section. It is characterized by being mixed at a desired constant ratio.

Hereinafter, the present invention will be specifically explained in detail using accompanying drawings.

FIG. 1 shows a basic embodiment of the device according to the invention.

In the figure, 3 is a mixing part, for example a line mixer, which mixes the water glass aqueous solution and carbon dioxide. This mixing section 3 is connected to a water glass flow system and a carbon dioxide flow system.

The water glass flow system is composed of a pipe 13 connecting the water glass, a valve 11 and a pump 6 installed in this pipe 13, and the water glass flow system includes a carbon dioxide storage tank 2, e.g. It consists of a pressurized liquid carbon dioxide gas cylinder, a pipe line 14 connecting the storage tank 2 and the mixing section 3, and a check valve 12 installed in the pipe line 14. 22 is a valve.

Further, any part of the water glass flow system, for example, the pump 6
A water glass flow rate detector 7 is installed in the downstream pipe line 13, and a water glass flow rate detector 7 is installed at any arbitrary point in the mixing section 3, the water glass flow system, or the carbon dioxide flow system, for example, in the pipe line 14. A carbon dioxide pressure detector 10 is installed, and a carbon dioxide flow system, for example, a valve 22 and a carbon dioxide pressure detector 1 are installed.
A carbon dioxide flow rate regulating valve 5 is installed in the conduit 14 between the carbon dioxide and the carbon dioxide flow rate. Furthermore, the device of the present invention is equipped with a ratio setting device 4, which is connected to the flow rate detector 7 via the circuit A1 and to the carbon dioxide pressure sensor 10 via the circuit A3, and It is connected to the carbon dioxide gas flow regulating valve 10 via circuit BT. Note that 23 is a liquid receiving tank for the mixed liquid. Specifically, a digital controller, such as a direct digital loop controller, is used as the ratio setter 4.

The device of the present invention configured in this way can be stored without being discarded! The water glass aqueous solution in the tank is fed to the mixing section 3 through the valve 11 and the pipe line 13 by the operation of the pump 6. In this case, the water glass aqueous solution can also be allowed to fall naturally without using the pump 6. The flow rate value of the water glass aqueous solution per unit time at this time is detected by the flow rate detector 7 and transmitted to the ratio setting device 4 through the circuit A1.

On the other hand, the carbon dioxide gas in the carbon dioxide gas cylinder 2 passes through the valve 22 and the check valve 12, passes through the conduit 14, and is sent to the mixing section 3. At this time, the pressure of the carbon dioxide gas is detected by the carbon dioxide gas pressure detector 10. This value is transmitted to the ratio setter 4 through the circuit A3. Based on this information, the ratio setting device 4 gives an instruction to the carbon dioxide flow rate adjustment valve 5 through the circuit B1, and the carbon dioxide flow rate adjustment valve 5 receives this instruction.
adjusts the flow rate of carbon dioxide gas flowing through the pipe 14 so that the flow rate ratio of the water glass aqueous solution and carbon dioxide gas is maintained at a constant ratio determined by the ratio setting device 4. That is, the ratio setting device 4 calculates the flow rate of carbon dioxide gas in accordance with the pressure of carbon dioxide gas so that the absolute flow rate of carbon dioxide gas becomes a predetermined ratio with respect to the flow rate of the water glass aqueous solution, and calculates the flow rate of carbon dioxide gas through circuit B1. The flow rate adjustment valve 5 is controlled by giving instructions to the adjustment valve 5. As a result, the water glass aqueous solution and the carbon dioxide gas are mixed at a desired constant ratio in the mixing section 3, and a water glass-carbon dioxide gas mixture having a desired composition is formed. This mixed liquid is in the liquid receiving tank 2.
3, the liquid is received and injected into the ground.

□Incidentally, the lines 13 and 14 may be directly connected to a line of a multiple injection tube as described later, and both components may be mixed at a predetermined position of the injection tube. Indeed, the two components may be mixed after being discharged from the injection tube. In the case of both of the above,
In both cases, the injection pipe serves as the mixing section.

4Fj. The pressure detector 10 is a device that detects the pressure related to the feeding pressure of carbon dioxide gas, and is installed in the water glass feeding system such as the mixing section 3 or the pipe line 13 to detect the pressure related to the feeding pressure of carbon dioxide gas. Pressure may also be sensed indirectly. Furthermore, the water glass aqueous solution in the storage tank 1 may be a mixture of water glass and a reactant, in which case carbon dioxide acts as a promoter.

As shown in FIG. 2, the device of the present invention is equipped with a pressure detector 8 for detecting the pressure of the water glass aqueous solution in the conduit 13, and a circuit for transmitting this pressure value to the ratio setting device 4. A2 may be provided, and a flow rate detector 9 for detecting the flow rate of carbon dioxide gas may be further installed in the pipe line 14, and a circuit A4 for transmitting this flow rate value to the ratio setting device 4 may be provided. In this case, the ratio setting device 4 senses the current carbon dioxide gas pressure value and water glass flow rate value as well as the carbon dioxide gas flow rate value and water glass pressure value, and thereby detects the carbon dioxide gas absolute value with respect to the flow rate of the water glass aqueous solution. The current ratio of amounts (process value) is grasped, and the regulating valve 5 is controlled so that the water glass aqueous solution and carbon dioxide gas reach a predetermined set ratio (cent value).

FIG. 3 shows a specific example of the apparatus of the present invention using multiple injection pipes as the mixing section 3 in FIG. In this type of device, water glass aqueous solution is sent through the pipe 15, and carbon dioxide gas is sent through the inner pipe 16, and both components are combined at the tip of the injection pipe and sent from the discharge port 21 to the ground. In addition, 17 is a check valve, and 18 is a metal crown.
By using the device of the present invention shown in the figure, a combined liquid of water glass and carbon dioxide gas is injected into the ground from the specified discharge port 21, rapidly solidifying the area around the injection pipe and rough strata, and then forming water glass and carbon dioxide into the ground. It is also possible to switch to a grout that has a longer gelation time and is made of a mixed solution of a reactant. Furthermore, the mixed solution of water glass and a reactant can be fed through the conduit of the outer tube 15, and
By intermittently feeding carbon dioxide gas from the pipe line 6, the mixed liquid V
The combined liquid may be injected into the ground without moving the stage. Alternatively, the water glass aqueous solution and carbon dioxide gas may be combined and injected by using a Sakae pipe as the injection pipe and passing through a 7-shaped pipe above ground.

FIG. 4 shows a specific example of the apparatus of the present invention, which is the apparatus of FIG. 3 and further equipped with a reactant flow system. Reactant flow system 1, storage tank J' for reactant aqueous solution, pulp 11', pump 6',
It is configured by communicating with the flow path 13 via a flow rate detector 7' and a pressure detector 8'.

In this device, water glass and a reactant are combined in a pipe 13,
This combined liquid is injected into the ground from the discharge port 21 through the conduit of the outer pipe 15, while carbon dioxide gas is intermittently injected from the conduit of the inner pipe 16, and the ground is improved while moving the injection stage. be.

Furthermore, this device can improve the ground by injecting a predetermined amount of a combined liquid of water glass and carbon dioxide gas, then switching to a mixed liquid of water glass and reactant, and moving the injection stage. The rest is the same as the example shown in FIG.

Figure 5 uses a triple tube instead of the injection tube in Figure 3,
A specific example of the apparatus of the present invention will be shown which is equipped with a flow system for the water glass and reactant mixture. The triple tube serving as the mixing section 3 is the outer tube 1.
5 and the inner tube 16, and a lower outlet 21 that communicates only with the middle tube 20. The system is a storage tank of water glass and reactant mixture 1" and a pulp 1.1"
", pump 6", diversion detector 7", and pressure detector 8
Furthermore, the pipe line 14 is connected to the pipe line of the outer pipe 15, and the pipe line 13 is connected to the pipe line of the inner pipe 16.

In this type of device, a liquid mixture of water glass and carbon dioxide gas is injected from an upper discharge port 19, and a liquid mixture of water glass and a reactant is injected from a lower discharge port 21, and these are used together to improve the ground.

FIG. 6 shows an example in which the apparatus shown in FIG. 3 is further provided with a second carbon dioxide flow system.

The second carbon dioxide flow system has a similar structure to the existing one. In the figure, 2 is a carbon dioxide storage tank, 22' is pulp, 5' is a carbon dioxide gas flow rate adjustment valve, 10' is a carbon dioxide gas pressure detector, 9' is a carbon dioxide gas flow rate detector, 14' is a pipe, and 12' is a carbon dioxide gas flow rate detector.
' is a check valve, and A'3, A'4, and B'1 are respective circuits. The pipe lines 13 and 14 are respectively connected to the pipe line of the outer pipe 5 of the injection pipe, and connected to the pipe line of the inner pipe 1G of the pipe line: +-4'U.

In this type of device, the mixture of water glass solution and carbon dioxide gas is adjusted to a mixture that has a long gelation time.
While injecting into the ground from the discharge port 21 through the pipe,
Further, carbon dioxide gas is intermittently added to this mixed liquid through the pipe line of the inner pipe 16 to adjust the mixed liquid to a short gelation time, and the mixture is injected, and these injections are used together to improve the ground. That is,
The liquid mixture of water glass from the storage tank 1 and carbon dioxide gas from the carbon dioxide gas cylinder 2 is adjusted by the regulating valve 5 so that it becomes a mixed liquid with a long gelation time in the conduit of the outer tube 15, and the gelation time is The adjustment valve 5' is used to adjust the blended liquid with a long gelation time so that it mixes with the carbon dioxide gas from the carbon dioxide gas cylinder 2' and has a short gelation time.First, when a predetermined amount of the blended liquid with a short gelation time is injected, the ratio is set. According to instructions from the container 4, the merging of carbon dioxide gas is stopped and a blended solution with a long gelation time is injected, and the above steps are repeated while moving the stage.
Automatically improve the ground.

In addition, in the present invention, the flow rate of the water glass aqueous solution or carbon dioxide is measured by measuring a change in the weight of the storage tank 1 or a change in the water level in the storage tank, respectively, and converting the results to calculate the flow rate of the water glass aqueous solution. Similarly, it is also possible to calculate the flow rate of carbon dioxide gas by measuring and converting changes in the weight of the carbon dioxide gas cylinder1.In this case, these detectors for changes in carbon dioxide gas are considered to be flow rate detectors. .

That is, in the present invention, the detectors for these changes in the surrounding area are also expressed as flow rate detectors. In addition, in the above, a line mixer, such as a static mixer, can be used as an example of the mixing part, or a mixer with a high-speed stirring blade built into the mixing part can also be used. A pipe can be used as a mixing part, or a pump can be used as a mixing part by sucking carbon dioxide gas and water glass directly into the pump and mixing them inside the pump.

[Brief explanation of the drawing]

1 to 6 each show an example of a device according to the present invention. 1.1', 1"...Storage tank, '2,'2'...
...Carbon dioxide cylinder, 3.Mixing section, 4.Ratio setter, 5.Block/adjustment valve 6.6', 6
〃... Pump 7.7', 7〃, 9.9'... Flow rate detector 8.8
', 8, 10.10'... Pressure detector 13.
14...Pipe lines A1, A2, A3, A4, A3', A 41, B1, B
, l...Circuit patent applicant: Reinforced Earth Engineering Co., Ltd. Representative Patent Attorney Hitoshi Someya Procedural Amendments Director of the Patent Office Kazuo Wakasugi 1, Indication of Case 1982 Special Revision No. 163362 2, Invention Name of ground injection method and device 3, relationship with the case of the person making the amendment. Engraving of the patent applicant Mi-Ebirmon-Koyoi, 3-15-1 Hongo, Bunkyo-ku, Tokyo. (No change in content)

Claims (1)

[Claims] 1. A ground injection method in which a water glass aqueous solution from a water glass distribution system and carbon dioxide from a carbon dioxide distribution system are mixed at a desired constant ratio in a mixing section and injected into the ground, The flow rate value of the water glass aqueous solution is transmitted from the water glass flow system to the ratio setting section, and the pressure value of the carbon dioxide is transmitted from the water glass flow system, the carbon dioxide flow system, and the mixing section to the ratio setting section. and in response to instructions from the ratio setting section described in iii), the flow rate ratio of the water glass aqueous solution and carbon dioxide is maintained at a constant ratio determined by the ratio setting section. A ground injection method characterized in that the water glass aqueous solution and carbon dioxide are mixed at a desired constant ratio in the mixing section by adjusting the flow rate of the water glass solution and carbon dioxide. 2. A mixing section that mixes the water glass aqueous solution and carbon dioxide;
a water glass flow system communicated with the mixing section; a carbon dioxide flow system further communicated with the mixing section; a water glass flow rate detector installed in the water glass flow system; A carbon dioxide pressure detector installed in a water glass flow system or a carbon dioxide flow system, a carbon dioxide flow rate adjustment valve installed in the carbon dioxide flow system, the water glass flow rate detector, carbon dioxide pressure detection and a ratio setting device respectively connected to the water glass flow rate detector and the carbon dioxide flow regulating valve, and the ratio setting device receives the water glass flow meter value and the carbon dioxide pressure value from the water glass flow rate detector and the carbon dioxide pressure detector, respectively. Upon receiving the information, an instruction is given to the carbon dioxide flow regulating valve based on this information, and upon receiving this instruction, the carbon dioxide flow regulating valve maintains the flow ratio of the water glass aqueous solution and carbon dioxide at a constant level determined by the ratio setting device. Adjust the flow rate of carbon dioxide to maintain the ratio,
As a result, the water glass aqueous solution and carbon dioxide are 1) 1f
2. The device for use in the ground injection method according to claim 1, wherein the mixing portion mixes the materials at a desired constant ratio.