JPH0421009B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to the injection of chemical liquids for ground improvement, in which chemical liquids of different types or properties are injected from different injection ports in the depth direction, such as instant-setting chemical liquids and slow-setting chemical liquids. The present invention relates to a device for injecting a medicinal solution while alternately repeating short-time ejections.

[Technical background of the invention and its problems]

The construction method that uses a quick-setting chemical solution and a slow-setting chemical solution is
Patent Publication No. 58-30966 invention and patent application No. 55-102201
There is a teaching by the No. 2 invention. This type of so-called composite injection method has the advantage of being able to perform fine-grained injection depending on the soil properties.

However, it has been known for a long time that in order to perform fine injection, it is sufficient to reduce the unit injection amount. However, with conventional infusion pumps, it is difficult to inject low unit injection volumes, or the improvement effect commensurate with the low unit injection volume cannot be obtained.
Based on the idea that the desired improvement effect can be achieved by increasing the injection rate to a certain extent, the conventional unit injection rate was usually set to exceed at least 12/min.

On the other hand, when looking at infusion pumps, for example, when using a 4-cylinder twin plunger pump, based on the idea that eliminating pulsation as much as possible during injection enables fine injection, A
When one plunger on the liquid side enters the discharge process, the other plungers enter the suction process (the same applies to the B liquid side).

[Object of the Invention] The present inventor fundamentally reviewed and studied the above-mentioned prior art, and obtained the following knowledge. In other words, firstly, when attempting to improve any type of ground by finely injecting it, the composite injection method using a fast-setting chemical solution is most suitable. If this is done while switching the flow path, not only is the switching work time-consuming, but
Since it is not possible to perform alternate injection as in the present invention, it has been found that it is preferable to use an injection tube with three or more channels.

Second, if a slow-setting chemical is injected into the tip after forming an improved zone with a fast-setting chemical, a considerable amount of ground deformation will occur due to the injection of the fast-setting chemical, and the slow-setting chemical has already been formed. Due to the presence of an improved zone of instant-setting chemical solution, it becomes a packer and can temporarily prevent outflow toward the proximal side near the injection tube. In addition, in the method of injecting fast-setting chemicals and slow-setting chemicals at the same time, an improvement zone due to the fast-setting chemicals has already been formed by the time the slow-setting chemicals are injected. In many cases, it is difficult to break up the loosely set chemical solution and uniformly inject it into the surrounding area. In other words, if a slow-setting chemical solution is injected when an improved zone with a flash-setting chemical solution has already been formed, this will split the weak spots in the improved zone of the instant-setting chemical solution, and the injection will mainly occur through the initial crack. This makes it difficult to perform homogeneous injection. Furthermore, even if the base side injection port and the distal side injection port are separated by a considerable distance, homogeneous injection may not be performed based on the construction results.

On the other hand, with alternate injection, the slow-setting drug solution is gradually injected while the improvement with the instant-setting drug solution is being gradually carried out, so the slow-setting drug solution can be instantaneously distributed in all directions without difficulty. The condensing drug solution zone is divided and injected homogeneously. Moreover, from the results of the actual work, although the reason is not clear (it may be because homogeneous injection is possible), the strength is greater than in the case of conventional two-way composite injection.

Therefore, it is a major finding that alternate injection of fast-setting chemical solutions and slow-setting chemical solutions causes almost no ground deformation, and that even if the amount of injected chemical solutions is small, the improvement effect is large.

Third, although it has traditionally been considered desirable to eliminate infusion pump pulsation as much as possible in order to achieve a good infusion, this idea is completely incorrect when actually using a pulsating infusion pump in conjunction with alternating infusions. Furthermore, it has become clear that the infusion pump according to the present invention allows for easy and small-sized injections to inject low unit doses, allowing for detailed injections.

As described above, the purpose of the present invention is to provide a method suitable for implementing a chemical injection method that reduces the outflow of chemical liquid and deformation of the ground, provides a large improvement effect even if the amount of chemical liquid used is small, and allows for miniaturization of the injection pump. The goal is to provide equipment.

[Structure of the invention]

The device of the present invention for achieving this object has three or more flow paths, and uses two of the flow paths to inject the first chemical solution from the first injection port formed on the base side of the injection tube, and the second The first method using a flow path other than the flow path
an injection tube into which a second chemical liquid different from the medical liquid is injected from a second injection port distal to the first injection port, each having a suction port and a discharge port;
and a plunger pump comprising first to fourth plunger boxes, each of which has a second plunger for discharging the first chemical solution, and a third and fourth plunger for discharging the second chemical solution, each of which has a plunger therein, In the plunger pump, liquids discharged by the first and second plungers are combined and injected from the first injection port, and liquids discharged by the third and fourth plungers are combined and injected from the second injection port, respectively. , driving the first and second plungers so as to be driven simultaneously with each other;
The driving of the third and fourth plungers simultaneously is characterized in that when the ejection operation of one pair is completed, the ejection operation of the other pair is started.

[Specific examples of the invention]

Next, the present invention will be further explained in detail with reference to a specific example in which an instant-setting chemical liquid is used as the first chemical liquid and a slow-setting chemical liquid is used as the second chemical liquid shown in the drawings.

FIG. 1 shows the basic concept of an example of a chemical liquid injection method when the device of the present invention is applied. A three-channel injection tube 1 is used, with a first injection port 18 on the base side and a second injection port on the distal side. An injection port 20 is formed in advance, and an instant-setting drug solution is injected.
The A and B liquids constituting G _S are independently led to the vicinity of the first injection port 18 using two channels, are combined and mixed, and then injected from the first injection port 18 . slow-setting drug solution
Liquids C and D constituting G _L are combined in front of the swivel using a Y-tube or the like or within the swivel, and then injected from the second injection port 20 using another flow path.

In the present invention, the unit injection amount of the medicinal solutions G _S and G _L is set to a low injection amount of 12/min or less, preferably 6/min or less, and up to 1/min, and the drug solutions are slowly injected under pressure. In addition, the unit injection time T of the chemical solutions G _S and G _L is set to 0.1 to 10 seconds, and for example, after the instant-setting drug solution G _S is injected, the slow-setting drug solution is
Perform short alternating injections of _GL .

Ground improvement is carried out in a predetermined depth range by advancing or pulling up this alternate injection, or a combination thereof.

Next, the construction method using the pulling method, which is preferable in terms of ease of construction, will be explained with reference to FIG. Drill the hole to a specified depth while Next, as shown in figure b,
Injecting G _S , and after a short time, injecting the slow-setting drug G _L as shown in Figure C, is repeated alternately.
While applying rotational force and pulling force or only pulling force to the injection tube 1, perform up to f, and finally
to be removed.

With this kind of alternate injection, in addition to the original effects of compound injection, the fast-setting chemical liquid G _S and the slow-setting chemical liquid G _L are injected at a low unit discharge volume, allowing for fine-grained injection without forcing the ground. This makes it possible to perform injections with a large improvement effect with a small amount of chemical solution. Since the quick-setting drug G _S is continuously injected with a short pause, it compensates for the outflow or escape of the slow-setting drug, which is also continuously injected. However, certain improvements can be made.

On the other hand, whether it is a 3-channel injection tube or a 4-channel injection tube, when injecting without switching the flow paths in the injection tube, use two 4-channel, 2-cylinder plunger injection pumps as shown in Figure 3. ₁ and _P2 , when carrying out the method of the present invention, one four-barrel, four-barrel plunger injection pump is sufficient, as shown in FIG. 4 or FIG. 5.

In FIG. 3, 2 is a crankshaft, and the first to fourth pins 2a have a phase shift of 180 degrees,
First to fourth plungers 4a to 4d are arranged on these via connecting rods 3. 5 is a valve at the suction port, and 6 is a valve at the discharge port. in this case,
The suction hose 7 and discharge hose 8 for liquid A are common to the first and second plungers, and when the first plunger 4a is in the discharge process, the second plunger 4b is in the suction process and discharges liquid A. In this case, the pulsation is eliminated. B
The same applies to liquids. Then, pump _P1 discharges liquids A and B to form instant setting chemical liquid G _S ,
Pump _P2 discharges liquids C and D to create a slow-setting chemical liquid.
Configure G _L.

This requires two pumps P ₁ and P ₂ ,
It is very uneconomical, and especially when using a highly viscous drug, it is impossible to suck in and discharge a small amount of drug, making it unsuitable for injection of small unit injection amounts.

On the other hand, as shown in FIG. are commonly connected, and the third and fourth plungers 4c and 4d are commonly connected to the pin 2'b, and a suction hose 7 and a discharge hose 8 are connected to each of the plungers 4a to 4d, respectively. Then, the quick-setting chemical solution G _S and the slow-setting chemical solution G _L are alternately injected every half rotation of the crankshaft 2'.

Further, as shown in FIG. 5, the conventional crankshaft 2 can be used for modification.

Further, although the above example is an example of a mechanical drive, in the case of a hydraulic plunger pump, a hydraulic system may be provided for each plunger, and alternate injection may be performed by controlling the opening/closing timing of a hydraulic control valve.

Next, an example of an injection tube suitable for the present invention will be shown.

Figures 6 to 11 show the structure of the three-channel injection pipe along with the construction process. Figure 6 shows the process of feeding drilling water W during the drilling process, and Figure 7 shows the instant setting chemical Both A and B liquids of G _S are supplied, and the first injection port 18
The process of injecting the combined liquid G _S from the
The process of injecting the slow-setting chemical solution G _L from the second injection port 20, FIG. 9 is a step-up (pulling up)
10 shows the step of injecting the slow-setting drug solution after step-up, and FIG. 11 shows the step of injecting the quick-setting drug solution G _S after the step-up.
Each of the steps of cleaning the inside of the injection device with cleaning water W' is shown.

Please note that the drawing shows only the tip device part.
A main body tube consisting of, for example, three flow path tubes is provided at this base, and is further connected to a swivel.

In the drawings, reference numeral 10 is a first outer tube, 12 is a second outer tube, and 14 is a tip tube having a bit 16 at its tip, which are successively screwed and connected to the tip side. A plurality of first injection ports 18 are formed around the circumference of the first outer tube 10 so as to penetrate in the radial direction, and the vicinity of the first injection ports 18 constitutes a first injection port portion of the outer tube. ing.
Further, a plurality of second injection ports 20 are formed in the second outer tube 12 at intervals in the depth direction with respect to the first injection port 18 and penetrate in the radial direction and in the circumferential direction. The vicinity of the inlet 20 constitutes a second inlet portion of the outer tube.

On the other hand, inside the first outer tube 10, there is a bottomed valve seat portion 22.
A and a spool valve 22 having a joint pipe portion 22b integrated with the joint pipe portion 22b by screwing are movably housed inside the spool valve 22. Also, inside the first outer tube 10, a middle joint 2 is provided.
4 is integrated with this by screwing, and the first outer tube 10
are concentrically provided with a gap between the base and the joint tube portion 22b. In this way, the base of the joint pipe part 22b is inserted into the (most) inner pipe of the main body pipe (not shown), and the middle joint 24 is inserted into the middle (intermediate) pipe, so that the material is fed through the inner pipe. Liquid A is in the joint pipe part 2
B liquid enters the A liquid path 26 in 2b, passes through the gap between the inner tube and the middle tube, enters the B flow path 28 in the gap between the joint tube part 22b and the middle joint 24, and further flows into the outer tube of the main body tube. Perforation water W or slow-setting chemical solution passing through the gap with the middle pipe
G _L is guided to the C channel 30 between the middle joint 24 and the base of the first outer tube 10 .

When liquid A is fed, the check valve 32 is pushed down against the biasing force of the spring 34, and then the valve seat 2
Liquid B is discharged from a plurality of discharge ports 36 formed in 2a to a mixing chamber 38 formed by a gap between the first outer pipe 10 and the spool valve 22 behind the first injection port 18, and the B liquid is Sometimes, the joint pipe part 2
The liquid is discharged into the mixing chamber 38 while pushing down the entire spool valve 22 via the shoulder portion of the spool valve 2b. And A,
After both liquids B are countercurrently mixed in the mixing chamber 38, they are transferred to the first injection port 18 as an instant-setting chemical liquid G _S.
It is poured out into the surrounding ground.

On the other hand, a stop ring 40 is provided to be regulated by the distal end surface of the first outer tube 10 and the stepped portion of the inner surface of the second outer tube 12. A blockage valve 42 with a conical tip is provided inside the stop ring 40, and since an O-ring 44 is initially provided on the stop valve 42, it will not slip out forward from the stop ring 40. Spool valve 2
It is arranged adjacent to the distal end surface of No. 2. Further, in the inner thickness portion of the first outer tube 10 and the stop ring 40, a plurality of communication holes 46, 4 forming a C flow path are provided in parallel with the axis.
8 is formed, and as a result, the drilling water W or the slow-setting chemical liquid G _L is guided from the C channel 30 through the communication holes 46 and 48 to the front of the stop ring 40 .

50 is an annular valve, and a spring 5 is attached to the second outer tube 12.
It is housed inside so that it can be moved freely in a state where it is energized. The annular valve 50 has a distal end with a second outer surface.
The inner diameter of the outer tube 12 matches the inner diameter of the outer tube 12, and the outer surface of the proximal end side thereof is smaller than the inner diameter of the second outer tube 12, thus forming an annular passage 54 between the outer tube 12 and the second outer tube 12. During drilling and instant-setting chemical injection, the annular valve 50 is biased toward the base by the spring 52, as shown in FIGS. 6, 7, and 9. The annular valve 50 closes the second injection port 20, and the annular valve 50 moves toward the distal side via the closing valve 42, as shown in FIGS. When the stop is pressed down, the second injection port 20 is opened. Furthermore, in the state shown in FIG. 6, the distal end of the closure valve 42 is inserted with some play into the proximal opening of the annular valve 50, and after the closure valve 42 is pushed out from the stop ring 40, ( 7 to 11), the closing valve 42 is tightly fitted and closed. In addition, the return from the state shown in FIG. 11 to the state shown in FIG. 7 is achieved by stopping the supply of the chemical solution, and by utilizing the repulsive return force of the spring 52 that has been pressed down, the annular valve 50 is returned to the state shown in FIG.
and by moving the blockage valve 42 toward the proximal end.

The device configured as described above operates as follows.

First, while applying rotational force and pressure force to the injection tube,
As shown in FIG. 6, drilling water W is supplied, passes through the C channel 30, the communication holes 46 and 48, passes between the blockage valve 42 and the proximal opening of the annular valve 50, and passes through the annular valve 50.
The hole is drilled to a predetermined depth while being guided into the inner passage 56 and ejected forward from the ejection port 58.

When the specified depth is reached, as shown in Figure 7,
Both A and B liquids are supplied to the A liquid path 26 and the B liquid path 28, respectively, and the spool valve 2 is controlled by the feeding pressure of the B liquid.
2, the instant-setting chemical liquid _GS is injected from the first injection port 18 by merging and mixing in the mixing chamber 38. At this time, as the spool valve 22 is pushed down, the closing valve 42 comes out of the stop ring 40 and tightly fits into the proximal opening of the annular valve 50 to close it.

Next, without moving the injection tube, at the same position, the loosely set chemical solution G _L , which has been merged in advance with a Y-shaped tube in front of the swivel, is introduced into the C channel 30 at the same position, and this is passed through the communication holes 46 and 48. Pass it through. Chemical solution G _L exited from ring stopper 40
With the closure of the annular valve 50 by the closure valve 42, there is nowhere to go, so pressure is applied to the protrusion at the distal end of the annular valve 50 and the base end surface of the closure valve 42, and while pushing down the annular valve 50, It is injected from the second inlet 20 through the annular passage 54 .

Next, the injection tube is stepped up to a predetermined length, and in the next step, the instant-setting drug G S is injected by the same operation as shown in Fig. 9, and the slow-setting drug G _S is injected by the same operation as shown in Fig. 10. An injection of _L is made.

After that, the steps are raised one after another, and the chemical solutions G _S and G _L are injected at each step. Before the final removal, cleaning water W' is supplied to the A, B, and C channels 26, 28, and 30. , first and second inlets 18,
Each channel is cleaned while pouring from 20.

On the other hand, as shown in FIG. 12, an inlet 50'a may be formed in the peripheral wall of the switching valve 50', and this may be closed or opened by a cap-shaped closure valve 42'.

Note that if the slow-setting chemical solution G _L is to be discharged from the tip of the injection tube, the spool valve 22 should not be made movable but should be fixed in position as shown in FIG. Valve 50 is not required.

On the other hand, a four-channel injection pipe may also be used, and for example, a publicly known one such as that disclosed in Japanese Patent Application Laid-open No. 57-96119 can be used.

〔Effect of the invention〕

As described above, according to the present invention, since the injection is performed alternately with a low unit injection amount and a short unit injection time,
It is suitable for performing highly effective ground improvement with a small amount of chemical solution without causing ground deformation or spillage or loss of chemical solution, and it only requires one injection pump.
Moreover, it is economical because it is sufficient to partially improve the conventional injection pump without making any special improvements.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram conceptually showing an example of a drug injection method to which the device of the present invention is applied, Figs. 2 a to f are sectional views showing an example of turning using the pulling method, and Fig. 3 is an example of use of a conventional injection pump. Schematic diagrams showing, Figures 4 and 5
The figure is a schematic diagram showing an example of an injection pump according to the present invention, Figures 6 to 11 are longitudinal sectional views showing the structure and operation of a three-channel injection pipe in the order of construction steps, and Figure 12 is a modification of the injection pipe. FIG. 3 is a vertical cross-sectional view partially showing an example. 1... Injection pipe, 2, 2'... Crankshaft, 2a,
2'a...Pin, 4a-4d...Plunger,
7...Suction hose, 8...Discharge hose, 18...
1st inlet, 20...2nd inlet, G _S ...snap-setting drug solution, G _L ...slow-setting drug solution, A, B...liquid constituting the flash-setting drug solution, C, D... Liquids constituting the slow-setting chemical solution, W...Drilling water, W'...Washing water.

Claims (1)

[Claims] 1 It has 3 or more channels, and uses those 2 channels to
A drug solution is injected from a first injection port formed on the base side of the injection tube, and a second drug solution different from the first drug solution is injected into the distal side of the first injection port using a channel other than the two channels. The injection tube has a suction port and a discharge port, respectively, and the first and second plungers are for discharging the first drug solution, and the third and fourth plungers are for discharging the second drug solution. a plunger pump equipped with first to fourth plunger boxes for discharge and each having a plunger therein; the liquid discharged by the first and second plungers joins and flows from the first injection port to the third plunger box; and the liquid discharged by the fourth plunger is combined and injected from the second injection port, and in the plunger pump, the first and second plungers are driven simultaneously. A chemical liquid injector characterized in that the third and fourth plungers are driven so that when the ejection operation of one pair is completed, the ejection operation of the other pair is started.