JPH07109093B2 - Ground hardening material High pressure injection injection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a so-called CCP among the ground hardening material injecting methods according to the applicant's patent for construction for the purpose of improving soft ground, foundation of building structures, etc. Construction method (Patent No. 825018, No. 81803)
No. 4), which is far beyond the conventional single pipe construction method and is capable of sufficiently exhibiting performance equal to or higher than the super high pressure injection construction method using multiple pipes.

[Conventional Technology] Conventionally, a ground improvement method using a hardening material jet has achieved various developments. The conventional historical flow of these construction methods is as shown in FIG.

That is, FIG. 1A shows the oldest type, in which only the curing material is injected (single pipe 56, patent Nos. 825018 and 818034), but next, injection by gas inclusion ( A double tube 57 and a patent No. 833214) have been developed (Fig. (B)).

However, various drawbacks have come to the fore, and while repeated trial and error, two injection ports are provided, and high-pressure water and gas are discharged from the upper injection port and only the hardened material is discharged from the lower injection port.
(Patent No. 1193367, No. 1098442, Fig. (C)) was discovered, and then a triple pipe 59 was made to inject gas from the lower injection port (Japanese Patent Application No. 1-3077, Fig. (D)). Came to appear.

By the way, the reason why these improvements were made is mainly to increase the injection force, improve the injection efficiency, ensure the construction, etc., and to increase the diameter of the ground-improved cylindrical solidified body, namely, the diameter. there were. In addition, in the conventional single pipe, there is a limit to the performance of the pump in which the hardened material should be press-fitted, and a mixture of powder such as cement milk and liquid has severe wear and the packings are broken in a short time. ,
Considering the fact that it was impossible to operate for a long time and had to entrust other means to realize efficient injection and strong injection, the multiple pipe construction method has to emerge from such a restrictive situation. It's no exaggeration to say that I didn't get it.

Here, the latest construction method using a triple pipe is shown in FIG. 4 and briefly described below. For more details, see Japanese Patent Application
See issues 1-3077.

That is, as shown in the figure, an upper injection nozzle 52 and a lower injection nozzle 53 having a superposition structure are bored in the side wall of the monitor 51 installed at the tip of the triple pipe 50, and the jet material is generated while rotating and raising the triple pipe 50. It is to jet. That is, from the upper injection nozzle 52, super-high pressure water that is wrapped around with pressurized gas and aimed at its induced drop is injected, and the gas used to remove and wash sludge and increase the power of the jet water is Next, when trying to escape to the surface of the earth, the lift effect makes it easy to discharge the cut sludge and water and create an artificial space in the soil. This is the so-called air lift effect.

After that, an attempt was made to create a high-quality improved body by rapidly and positively filling the above space with the ultra-high pressure curing material which was surrounded by the pressurized gas from the lower injection nozzle 53.

[Problems to be Solved by the Invention] It should be highly evaluated that the above-described conventional improvements have greatly contributed to the enhancement of injection force, the improvement of injection efficiency, and the like. Of course, for that purpose, the injection tube has a complicated multiple structure,
Alternatively, it must be said that the introduction of multi-model devices such as high-pressure water pumps and air compressors was an inevitable measure as the injection force was strengthened.

However, what the present inventor intends in these improvements is another point.

According to the improvements made so far, the injection force and the injection efficiency could certainly be sufficiently improved, but on the other hand, the introduction of a variety of complicated devices brings about a significant increase in cost. However, it also has a one-sided defect that the complexity and the difficulty of construction increase. In addition, the complicated injection pipe structure increases the manufacturing cost, and the high-pressure water and the pressurized gas used in the improvement process exert an outstanding effect such as an air lift effect and hit another new problem.

That is, the pressurized gas used to increase the power of high-pressure water discharges cut sludge and water to the ground due to its lift effect when trying to escape to the surface of the earth, but it is extremely difficult to process this rising sludge. The problem is that it requires a high cost. There is also the problem of diluting the concentration of the hardener with high-pressure water.

Furthermore, since the installation of multiple injection nozzles may cause a pressure difference between the injection objects, the reliability of the construction is improved.
There was also a problem that the improved body could not be kept uniform depending on the soil condition.

On the other hand, considering the pump performance of the conventional single pipe construction method at that time, the injection pressure was around 200 kgf / cm ² , and the curing material discharge rate was about 50 to 60 l / min. There was no compact ultra-high pressure pump that ejected several times more than the conventional one and operated for a long time. Therefore,
There is a situation in which there is no choice but to implement a method using multiple pipes in order to realize a large amount of injection with high pressure. Therefore, although the above-mentioned conventional improvements have one-sided defects, they are certainly progressive. However, as can be seen from the current situation, it can be said that the time has come to return to the original point of the single pipe, and to reconsider the improvement from a viewpoint different from the conventional one. In view of the above, as a result of repeated studies by the present inventor, it was found that an effect equal to or higher than that of the multiple pipe can be obtained by constructing the conventional single pipe construction method with a slight addition means.

The present invention, from this, a single tube that can sufficiently reach the capacity of the conventional multiple tubes, specifically, an injection pressure of 300 kgf / cm ² or more,
An ultra-high pressure injection method using a single tube with a curable material discharge rate of 100 l / min or more is provided.

This will simplify construction work and reduce costs significantly. Also, unlike conventional single pipes that create only cylindrical improvement bodies, unlike multiple pipes, improvement is necessary by adding a mechanism that can create ground improvement bodies of various shapes so that it can be adapted to all construction situations. The purpose is to improve the efficiency of the construction speed by not performing the construction in the areas not designated, and to further ensure the construction.

[Means for Solving the Problems] The structure of the ground hardening material high-pressure injection injection method according to the present invention for achieving the above-mentioned object is an injection pipe having a single fluid passage therein, wherein An injection pipe having a single hardener injection port communicating with the fluid passage and having a control valve for opening the fluid passage downward at the lower end and a drilling blade is used, and the control valve is opened. The injection hole is excavated by press-fitting the lubricating liquid into the injection pipe and lowering the injection pipe at a high speed while injecting the lubricating liquid downward, then closing the control valve at a predetermined depth, and then super high pressure. The ground hardening material is injected into the injection pipe at a high pressure by a pump, and the ground hardening material is injected from the hardening material injection port while injecting the hardening material at an injection pressure of 300 kgf / cm ² or more and a hardening material discharge rate of 100 l / min or more. A soil improvement body is created in the soil by rotating and raising the pipe. It is characterized in that.

In other words, it was decided to develop and adopt a pump with a higher delivery pressure than that conventionally used in the single pipe construction method. In other words, with the advent of ultra-high pressure slurry pumps,
Specifically, injection pressure 300 kgf / cm ² or more, curing material discharge rate 100 l / m
The above can be achieved, and for example, Japanese Patent Application No. 62-237.
If the object of the present invention can be achieved, for example, by applying a fluid pressure feeding device such as Japanese Patent Application No. 63-77075 to the pump device such as 996 to enhance the injection force, the pump may be configured according to the situation as appropriate. You can use it.

Besides, the valve devices of Japanese Patent Application Nos. 63-68882 and 63-88623, and Japanese Patent Application No.
There is a fluid pumping device of 63-79049.

Also, in some cases, the ground improvement body formed by limiting the rotation angle range of the injection pipe to within 360 degrees is not a columnar shape. The shape of the rod is not limited to the conventional circular shape, but is a quadrangle or a polygon, and the shape of the rod is changed according to the soil quality while paying close attention to the gap with the ground.

[Operation] Unlike the conventional single pipe, the hardened material is jetted with a force of 300 kgf / cm ² or more and a discharge rate of 100 l / min or more, so it becomes an ultra-high-speed fluid that collapses the target soil and forcibly stirs it. While mixing, the amount of soil that is more than twice the amount of soil improved by the conventional construction method is completed, and an extremely strong, uniform, economical and high-quality ground improvement body is created.

Embodiments Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic view of an ultrahigh pressure injection method using a single tube according to an embodiment of the present invention.

The injection pipe 10 is a so-called single pipe having a single fluid passage therein, has a single hardening material injection port 11 communicating with the inner fluid passage on the lower side wall, and has a downward fluid passage at the lower end. A control valve 12 and a drilling blade 14 that open the valve are provided.

Further, the upper end of the injection pipe 10 is connected to a rotary propelling / retracting mechanism 15 for operating the vertical movement of the injection pipe 10 while rotating and adjusting the rotation speed, and a hardening material injection port 13 connected to the ultrahigh pressure grout pump 20, and at the lower end. Is provided with a drilling blade 14. Therefore, if the injection pipe 10 is rotated at a high speed and lowered while the control valve 12 is opened and the lubricating liquid is press-fitted, the injection hole can be excavated by the injection pipe itself without special boring. Then, after excavating to a predetermined depth, the control valve 12 is closed, and the injection pipe 10 is rotated and raised while injecting a hardening material of 100 l / min or more together with a high pressure of 300 kgf / cm ² or more from the ultra-high pressure grout pump 20. By doing so, the curing material injection port 11
As a result, the ground hardening material becomes a high-speed fluid and is jetted, collapsing the target soil and mixing while forcibly stirring, and an extremely strong and high-quality ground improvement body is created.

Further, if the rotation angle is adjusted or limited by the automatic control device 19, it is possible to form the improved body 21 having various shapes according to the construction situation as shown in FIG. For example, in the figure (a), the rotation angle is 45 degrees, (b) is 90 degrees, (c)
Shows a schematic shape of the improved body when limited to 180 degrees. Therefore, if the angle α is set to an arbitrary value by automatic control or the like, the rod will reciprocate within the range of the angle α, and the desired shape can be created.

By the way, there are already pumps that provide an injection force equal to or higher than that of a multiple pipe, but an ultrahigh pressure pump device as an example of the principle is disclosed in Japanese Patent Application No. 62-237996 and Japanese Patent Application No. 63-237996.
Since it is disclosed in detail in No. 58523 and the like, it is omitted here.

As a specific method, as described above, a fluid pressure feed device such as Japanese Patent Application No. 63-77075 is applied to the pump device of Japanese Patent Application No. 62-237996 to further enhance the injection force, depending on the situation. It is better to use a pump in the configuration.

The shape of the rod itself is not a conventional circular shape, but may be a quadrangular shape, a polygonal shape, or the like, and the rod shape can be changed according to the soil quality while paying close attention to the gap between the ground and the ground.

[Effect of the Invention] The present invention has the following effects due to the above-mentioned configuration.

That is, by adopting the above-mentioned ultra-high pressure pump as the first, forcibly mixing and stirring the hardening material and the conventional ground with a powerful ultra-high pressure injection that could not be realized by the conventional single pipe construction method, and an extremely strong ground improvement body Made possible. As a concrete comparison, as shown in Fig. 2, the injection pressure in the conventional single pipe is
While 200 kgf / cm ² and the curing material discharge amount were around 50 to 60 l / min, according to the present invention, 300 kgf / cm ² and 100 l / min, respectively.
The above becomes possible, and it can be said that this has a capability equal to or higher than that of the high-pressure injection method using multiple tubes.

From this, it is often the case that the simple single pipe construction method according to the present invention is sufficient, even if it is not necessary to use only the multiple pipe construction method by developing the high performance pump as described above. Has expanded the range of construction methods that can be selected according to the construction conditions and costs, but its significance is extremely significant.

Secondly, the conventional rod speed is 5r.p.
Although it was around m., the present invention made it possible to freely or easily adjust or limit the number of revolutions and the angle of rotation by automatic control, etc., so it is possible to create a ground improvement body with a shape that can be adapted to any construction situation. I have Therefore, it is possible to secure a reliable construction without leaving a useless space, as compared with the conventional case where it is difficult to form a structure other than the columnar improved body.

Now, the above-mentioned two main effects of the present invention cannot be reached by the conventional method. This is because the first effect is extremely difficult in the conventional single pipe construction method in view of the pump performance at that time, in other words, it can be said that the present invention can be achieved by the present invention at present.

Moreover, it is not only difficult to expect the second effect from the multiple pipe construction method having a plurality of injection ports, but it is also unreasonable for the purpose of the construction method. Therefore, it can be said that this effect can be easily realized because of the single tube and can be expected.

Therefore, these two effects can be exerted at the same time because they are the basic single tube and the recently disclosed ultra-high pressure pump, both of which existed in the past and organically combined the devices, and more than the total effect is produced. .

In addition, the present invention can sufficiently meet current construction needs without expensive treatment of rising sludge, dilution of hardener concentration, or the aforementioned differential pressure problems.

[Brief description of drawings]

FIG. 1 is a schematic view of a ground hardening material high-pressure injection injection method according to an embodiment of the present invention, FIG. 2 is a performance comparison table between the conventional and the present invention, and FIG. 3 is an improved body which can be formed by the present invention. Shape example, 4th
The figure shows a schematic diagram of the conventional triple pipe construction method, and Fig. 5 shows the historical flow of the ground hardening material injection construction method. 10 …… Injection pipe (single pipe) 11 …… Hardened material jet 12 …… Control valve 13 …… Hardened material inlet 14 …… Drilling blade 15 …… Rotary propulsion / retraction mechanism 16 …… Oil tank 17 …… Oil pump 18 …… Motor 19 …… Automatic control device 20 …… Ultra high pressure grout pump 21 …… Ground improvement 50,58,59 …… Triple pipe 51 …… Monitor 52 …… Upper injection nozzle 53 …… Lower injection nozzle 54… … Triple tube swivel 55 …… Operating mechanism 56 …… Single tube 57 …… Double tube

Claims (2)

[Claims] 1. An injection pipe (1) having a single fluid passage therein.
0) which has a single hardening material injection port (11) communicating with the fluid passage on the lower side wall, and has a control valve (12) for opening the fluid passage downward at the lower end and an excavating blade ( 1
4) Using the injection pipe (10) provided with and, the control valve (12)
With the lubricating fluid being pressed into the injection pipe (10) with the valve open, the injection pipe (10) is rotated at a high speed to descend while injecting the lubricating liquid downward to excavate the injected steel, and then a predetermined depth is reached. Then, the control valve (12) is closed, then the ground hardening material is injected into the injection pipe (10) at a high pressure by an ultra-high pressure pump, and the ground hardening material is injected through the hardening material injection port (11). 300kgf / cm ²
As described above, the ground hardening material high-pressure injection injection method for forming a ground improvement body in soil by rotating and raising the injection pipe (10) while injecting at a hardening material discharge rate of 100 l / min or more. 2. The ground hardening material high-pressure injection injection method according to claim 1, wherein the ground improvement body formed by limiting the rotation angle range of the injection pipe (10) to within 360 degrees is not a cylindrical shape.