JPS6250607B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chemical injection method that uses both instant-setting chemical liquid injection and slow-setting chemical liquid injection.

In recent years, a method using double pipes has become widely used as a chemical injection method. Also, the conventional gel time is 60
Instead of the method of osmotic injection of a slow-setting chemical solution that takes more than a second, the so-called LAG method uses an instant-setting drug solution that has an extremely short gel time as described in JP-A-52-48217.
Many construction methods are used. Now, if we consider osmotic injection using a slow-setting chemical solution and limited injection using an instant-setting chemical solution, the former is superior in that it allows the chemical solution to penetrate into sandy ground and achieve natural improvement, but it has disadvantages. For sandy soils that are homogeneous and saturated with groundwater, or for complex clayey soils, slow-setting chemicals may escape into weak layers or be diluted by groundwater, resulting in failure to achieve the desired results. There are disadvantages in that no improvement effect can be expected, and the curing time is long, making it uneconomical. On the other hand, the latter is extremely superior in that it can reliably improve the desired limited area without the escape of chemicals even in complex ground as described above, but it is slow to work on sandy ground. Due to the nature of the construction method, it is not possible to slowly osmotic inject a hard chemical solution.

In the field of chemical injection construction, these methods have developed independently to the present day, and equipment has also been improved to be suitable for these methods, and specialized equipment has been developed. .

The present invention was proposed based on the above background, and
In order to take full advantage of the features of both of the above construction methods, the following points have been devised.

(1) A plurality of channels are formed independently in the injection tube, and the liquid medicine discharged from the channels is configured to join inside the injection tube near the injection port or outside the injection tube. This eliminates any clogging due to solidification of the chemical within the tube even when the instant-setting chemical is fed.

(2) By injecting a combination of fast-setting and slow-setting chemicals, ground improvement can be achieved more effectively than when a single chemical is injected.

(3) If the flow path for the fast-setting drug solution and the flow path for the slow-setting drug solution are configured separately in the injection pipe, at least three channels are required even if the same base agent is used, and usually Four flow paths are required, which complicates the structure of the injection tube and increases its diameter.To avoid this, injection is made through the same flow path and the same injection port. the result,
Even if there are two flow paths, construction can be performed reliably.

(4) In order to make it possible to inject two types of chemical liquids with different properties through the same flow path, switching between the two types of chemical liquids is performed outside the injection tube. Conventionally, it has been known to switch the flow paths between the perforation lubricating fluid and the chemical fluid by operating a switching valve or the like provided inside the injection pipe.
It is not impossible to develop this idea and apply it to the two types of drug injections mentioned above.
If a switching valve or the like is installed inside the injection pipe, the structure will be complicated, and if cement-based chemicals are used, particles will settle near the switching valve, making it difficult to ensure its operation. There remains a technical problem that cannot be guaranteed. However,
If the switching is done outside the injection tube, the injection tube will have a simple structure up to the tip, which will solve the problem of clogging inside the tube. Even if there is a risk of deposition, it is within the control of the workers and can be easily dealt with.

(5) From the conventional technology, if the flow path of various liquids is to be switched as in the present invention, two pumps are prepared, four tanks are placed in front of them, and two Make the tank compatible with one pump,
A method of switching at the suction part of the pump will be adopted. However, since there is usually a long distance from the pump to the injection pipe, this causes problems such as delays in switching, and since two liquids flow inside the pump, there is a risk of reaction or sticking, which is a major problem.

In contrast, in the present invention, the switching is not performed at the suction part of the pump, but after the pump, so switching can be performed near the injection pipe, preventing time delays in switching, and Since a compatible pressure pump is provided, clogging in the pump can be reliably prevented.

(6) On the other hand, as mentioned in item (5) above, it is usually a long distance from the pump installed near the liquid tank to the injection pipe. If the undiluted solution is not sent to the injection pipe, the undiluted solution will remain in the pressure pipe between the pump and the switching valve, and especially in the case of cement-based stock solution, it will settle in the pressure pipe and cause various problems. may invite Moreover, not only is there a problem with deposition, but when the stock solution is then tried to be pumped again, if the previous stock solution remains in the pumping pipe, the concentration of the stock solution will change, making it impossible to obtain a drug solution with the desired properties. . and,
This state lasts for quite a long time. Moreover, this situation appears as a situation in which the property of the medicinal liquid cannot be appropriately and quickly switched when injecting the instant-setting medicinal liquid and the slow-setting medicinal liquid, which is the aim of the present invention. On the other hand, to switch the liquid, it is possible to temporarily stop the injection pump and then operate the switching valve, but this leaves the hassle of stopping and restarting the injection pump, and when the injection pump is restarted, the It takes a considerable amount of time for the stock solution to reach a stable, steady state of flow within the supply pipe.

Therefore, in the present invention, a relief valve is provided between the injection pump and the switching valve to return the stock solution to the liquid tank. The infusion pump is preferably operated continuously.
As a result, when the stock solution is not delivered to the injection pipe, the stock solution circulates from the pressure pipe to the liquid tank through the relief valve and return pipe, so that the stock solution, especially the cement particles of the cement-based stock solution, is deposited in the pressure pipe. There is no clogging in the pressure-feeding pipe, and when it is decided to inject again, the stock solution can be directly injected in a stable steady state without causing a change in concentration.

Next, the present invention will be explained using specific examples shown in the drawings. FIG. 1 shows an overall view of the apparatus. Reference numeral 1 denotes an injection tube main body, a distal end device 2 is provided at its distal end, and a two-liquid independent rotation swivel 3 is provided at its proximal end. The swivel 3 and the main body 1 are configured with an independent first flow path 4 and a second flow path 5. Further, the tip device 2 includes a mixer 6,
The liquids pumped through the channels 4 and 5 are scattered outward, pass through a gap 7 with the inner wall surface of the tip device 2, and are again collected in the direction of the central axis. The collected liquids are brought into contact and mixed in the mixing chamber 8,
It is discharged forward from the injection port 9.

On the other hand, in the present invention, selection and switching of the liquid to be fed to the flow path of the injection tube is performed outside the injection tube. That is, a lubricating liquid tank 10 for drilling, a main agent A liquid tank 20, a main agent B liquid tank 30, and a hardening agent solution tank 40 are provided, and pressure pumps 11, 21, 3 are provided, respectively.
1 and 41, each liquid is fed through pressure pipes 12, 22, and 3.
2,42. Pressure feed pipes 12, 2
Relief valve 1 with stabilizer for 2, 32, 42
3, 23, 33, 43 are installed, and when not feeding to the injection pipe, return pipes 14, 24, 34,
44 for return shipping. In addition, the flow path is switched using the switching valves 15, 16, 25, 35, 45.
The swivel 3 is provided with a feed pipe 50,
The selected liquid is delivered through 60. 26,3
6 is a flow rate and pressure recorder.

Next, the construction method will be explained with reference to FIGS. 2 to 5. First, bentonite aqueous solution, fresh water, air-mixed water, etc. are pumped from the drilling lubricant tank 10 to the pump 11.
The liquid is fed to the feed pipe 50 under pressure. At that time, each switching valve is operated so that liquid is fed only to the feed pipe 50. The lubricating liquid D enters the first flow path 4 from the swivel 3, is guided by the mixer 6, and is discharged from the inlet 9. At this time, the injection tube is bored to a desired depth while applying rotational force and pushing force. When drilling to a deep layer, if the hole wall is difficult to stand on its own, water is severely lost, it is difficult to remove slime, and there is a risk of hole bending or jamming, stop feeding the lubricant. However, instead of this, main agent solution A and curing agent solution C, which are instant-setting two-component curing chemical solutions, are sent from tanks 20 and 40 to feed pipes 50 and 60 by pressure pumps 21 and 41, respectively. It is forced to be fed to the channels 4 and 5. As a result, liquid A moves mixer 6 to the left side (first
(Fig.), liquid C goes around the mixer 6 from the right side,
In the mixing chamber 8, they are brought together, contacted and mixed almost countercurrently, and then discharged from the injection port 9. At this time, by advancing or withdrawing the injection tube, a firm hole wall X can be created.

Next, as shown in FIG. 3, the instant-setting two-component curing chemical solution is similarly pumped and discharged from the injection port 9 at a low discharge rate (8 to 12/min) to create the first injection zone Y. , to improve the ground in the vicinity. When this is completed, the slow-hardening chemical liquids, ie, main agent B liquid and curing agent solution C, are transferred from the tanks 30 and 40 to the pressure pump 3.
1 and 41 to the feed pipes 50 and 60, respectively, and pass through the inside of the injection pipe, and while mixing in the mixing chamber 8, the mixture is discharged from the injection port 9 at a low pressure and a low discharge amount. The discharged chemical liquid is transferred to the first injection zone Y
and is infiltrated into the surrounding ground through zone Y, creating a second injection zone Z. When this is completed, the step is advanced or withdrawn to the next step, and the injection of the fast-setting chemical solution and the injection of the slow-setting drug solution are repeated.

According to such a construction method, the limited improvement effect of the quick-setting chemical liquid and the improvement effect of the slow-hardening chemical liquid by infiltration injection combine to achieve suitable ground improvement. No matter how complex the ground is, the improvement effects of both can ensure reliable ground treatment.

In addition, as the instant setting chemical solution, for example, the A solution may be made of cement, slaked lime, or gypsum, and the C solution may be a water glass-based solution, and the gel time may be within 30 seconds, preferably within 15 seconds, and Preferably, it is within 5 seconds. In addition, if an instant-setting chemical solution and a slow-setting chemical solution are used together in the same step, an improvement zone as shown in Figure 5 can be created, and if the injection chemicals are selected according to the soil quality, an improvement zone as shown in Figure 6 can be created. You can create zones.

As a slow hardening chemical solution, one suitable for hardening for 60 seconds or more, more preferably for 2 minutes or more. However, gel time cannot be simply determined in practice. That is, the gel time should be selected depending on the target soil quality, and therefore, in the present invention, instant setting and slow hardening mean fast and slow gel times between the two components. .

Although the above-mentioned injection device mixes the two liquids almost countercurrently, they may be mixed in an orthogonal manner as shown in FIG. That is, while pushing down the ball check valve 100, the inner channel liquid is discharged from the discharge port 102 formed in the inner channel element 101, and the outer channel liquid is released by expanding the tongue piece 103a of the rubber annular check valve 103. The discharge port 102
The liquid is brought into contact with and mixed orthogonally with the inner channel liquid discharged from the inlet, and is injected from the injection port 104.

Furthermore, although the above-mentioned injection device mixes the mixture within the tube at the tip of the injection tube, it may be discharged from the discharge ports 200, 201 and merged outside the tube, as shown in FIG. Further, the injection port may not be directed toward the front of the tube, but may be directed toward the side of the tube as described in Japanese Patent Application Laid-Open No. 52-48217.

As described above, in the present invention, since the flow path is made independent up to the vicinity of the injection port, it is possible to prevent clogging in the pipe even when a quick-setting drug solution is used, and it is possible to prevent clogging in the pipe even when a quick-setting drug solution is used. Since both are used, it is possible to select the appropriate one depending on the target ground, and ensure reliable treatment.
Furthermore, since the chemical solution is changed outside the injection tube, there are advantages such as the structure of the injection tube is simplified and switching is easy.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the injection equipment, Figs. 2 to 5 are cross-sectional views showing an example of the injection method, Fig. 6 is a cross-sectional view showing another injection method, and Figs. 7 and 8 show the embodiments. FIG. 3 is a cross-sectional view of a different injection device. DESCRIPTION OF SYMBOLS 1... Injection tube main body, 2... Tip device, 3... Swivel, 4... First channel, 5... Second channel, 9...
...Inlet.

Claims (1)

[Claims] 1. Two independent channels are formed inside the injection tube, and the liquid medicine discharged from each of these channels is configured to join inside the injection tube near the injection port or outside the injection tube injection port, and instant connection is achieved. An independent pressure feed pipe is provided from the liquid tank for each stock solution of sex drug solution and slow hardening drug solution to a switching valve corresponding to each stock solution outside the swivel, and a pressure pump is installed independently in the middle of this pressure feed pipe, and corresponds to the pressure feed pump. If the stock solution is not being sent to the injection pipe, a relief valve and a return pipe for transporting the stock solution to the liquid tank should be installed between the switching valve and the switching valve as close as possible to the switching valve, and after the switching valve group, two feed pipes should be installed. is connected to a swivel with a swivel, and by operating the switching valve for each stock solution, the liquid to be currently fed into the injection pipe is selectively fed,
Using an instant-setting drug solution and a slow-setting drug solution as the drug solution to be force-fed to the injection pipe, and further operating a full pressure pump,
While switching between the pressure feeding of the instant-setting chemical solution and the slow-setting chemical solution by operating the switching valve group after the pressure pump, the instant-setting chemical solution and the slow-setting chemical solution are transferred to the target ground from the same injection port using the same flow path in the injection pipe. A chemical liquid injection method characterized by injecting a hard chemical liquid and returning uninjected stock liquid to the corresponding liquid tank via a relief valve and a return pipe.