JPS5924024A - Grout injection work - Google Patents

Abstract

PURPOSE:To improve the ground by expanding the slackening range of the pit wall by a method in which water is jetted under high pressures from the upper port opening in the right-angle direction in the lower part of a rod and also from the lower port opening in the slantly downward direction and the rod is driven forward while being turned. CONSTITUTION:A rod A is driven downwards while being turned by a driver and driven forward into soft ground. During the period, at the upper part of the bit at the top of the rod A, water 10 containing air bubbles is jetted from a nozzle 3 opening slantly downward and also air 20 is jetted under high pressures from the nozzle 6. By the water 10 and the air 20, the pit wall C' at the drilling point is degradated, and by forcibly removing slime 30, the diameter of the pit is expanded and the slackening range of the pit wall C' is increased. After the drilling operation reaches a given depth, a cement-based grout for improving the ground is injected from the nozzles 3 and 6, during which period the rod A is pulled out to complete the grout injection work.

Description

[Detailed Description of the Invention] The present invention relates to a chemical injection method for reinforcing and reinforcing soft ground, and more specifically, using a rod that penetrates and propels the ground,
This invention relates to an improvement in the method of injecting a soil improvement effect at the time when the rod is removed after reaching a predetermined depth.

In the conventional method that performs the above operations, water flows out from the bottom of the rod at low pressure when the rod is propelled into the hole, but this water only lubricates the drilling blade, and the function is to actively expand the diameter of the hole. The diameter of the hole in the conventional construction method is generally small, about a thousand times larger than the rod diameter, and the injection range when injecting the chemical solution is narrow.

In order to improve the above-mentioned problems of the conventional method, the present invention provides an upper opening opening perpendicularly to the lower part of the rod and a lower opening opening diagonally downward. By injecting air with turbulent pressure, the hole wall is collapsed G] and forcibly discharged onto the ground surface, expanding the hole diameter or expanding the loosening range of the hole wall, The purpose of this is to improve the soil improvement effect in combination with the subsequent injection operation.

The chemical injection method of the present invention uses a rod having an excavating blade at the lower end and having an upper opening opening perpendicularly above the rod and a lower opening opening diagonally downward, spaced apart vertically. When drilling with four throats, the rod is rotated while water and/or air is injected at high pressure from both the upper and lower ports, and when the rod is removed after reaching a predetermined depth, a ground improvement chemical solution is applied from the upper and/or lower ports. The feature is that the rod is rotated while injecting at high pressure.

If the same liquid (water or chemical solution) is to be injected from the upper and lower ports of the rod, it is optional to use a single tube; When employing a construction method, or a construction method in which each chemical solution is sprayed upward and downward, multiple pipes such as double pipes should be used.

The above-mentioned water includes both water containing a foaming agent and water without a foaming agent, and by using the former water, the soil discharge function (sand effect) can be improved.

To explain the embodiment of the present invention using a double pipe rod with reference to the drawings, the rod is inserted into the inner pipe (=) and the outer pipe (b) integrally while maintaining a constant distance. It has a double tube structure, and the lower end has an inner tube (111) protruding from the outer tube by an appropriate length.

Therefore, in the rod (g) K, an inner passageway (ay) is formed in the inner tube (a), and an outer passageway (b7) is formed between the inner tube (a) and the outer tube (b).

The inner tube (a) has a bit (1) projecting integrally from its lower end to seal the lower end of the inner passageway (PLγ).
A digging blade (2) (2) is provided at the lower end of 1).

The bit (1) is fitted with a nozzle (3) on its sloped portion at a constant circumferential interval, and the nozzle (3)...
- Form a lower opening opening diagonally downward.

The rod (A) also has a digging blade (4) at the lower end of the outer tube (b).
... and seal the external pipe (b'y) with the partition wall (5), and a nozzle (G) (6) is installed at the lower end of the outer pipe (b) slightly above the partition wall (5). Attach the nozzle (6) and connect it to the outside passage (by).
An upper opening opening in a direction perpendicular to the upper opening is formed.

Therefore, the chemical injection method using the above rod (4) was adopted as the second method.
This will be explained with reference to Figure 4.

The figure shows the case where a rod (A) is perpendicularly drilled into the ground, and the driving device (not shown) K (therefore, the rod) is rotated and lowered sequentially to propel the drilling (the second , Fig. 8), during this drilling propulsion, the nozzle (3)
The water containing the foaming agent *Q is sprayed at high pressure from each nozzle (6) (shared with the shear).

The drilling blade (
2) While (4) is lubricated, the water (II and the air ring injected from the nozzle (6)) disintegrates and agitates the earth and sand at the hole wall (disintegrates Ox and further into air) at the drilling point. to the slime) to the rod (A
) Forced to rise along the outer periphery and removed to the ground surface.

Therefore, the hole diameter (Cl) formed during the drilling process is forcibly removed by the slime, and the diameter of the hole is expanded, and the range of loosening of the hole wall (ay) is increased.

In addition, during the drilling process described above, a method of injecting a mixture of water and air at high pressure from the nozzle (3), or a method of spraying a mixture of water and air at high pressure from the nozzle (3),
It is also optional to adopt a construction method in which water or a mixture of water and air is injected at high pressure in place of the air (1) from 6).

Furthermore, if the ground above the borehole is likely to collapse or the borehole is deep, a casing may be inserted into the upper part of the borehole (0) as necessary.

Next, when the drilling was carried out to a predetermined depth, water 0 as described above
Q. Stop the supply of air (E), and open the inner passage (ay) and outer passage (by
Ground improvement chemicals such as cement beams and water glass (Q
The liquid injection operation is carried out by rotating and raising the rod while supplying the liquid and injecting it at high pressure through the nozzles (3) and (6), respectively (Fig. 4).

During this injection of accumulated liquid, the injected sputum (Q) is stirred and mixed with the earth and sand remaining in the hole (0), and further penetrates into the loosened part of the hole wall < ay to become even larger than the hole (C). A ground improvement area (■) is formed in a large diameter area.

In addition, when injecting the chemical solution above, the chemical solution (q) is injected into the nozzle (3).
) or (6), a method of spraying from only one of the nozzles (
3) Add water or air from the nozzle (6) to the chemical solution.
: Injection method or chemical solution (Q, l single chemical solution (C
tI), (Q,) are sprayed separately through the nozzles (3) and (6), and the chemical solutions (Qt) and (qt) on both sides are mixed in the perforation (0) to produce a hardening effect. You are free to adopt them.

Further, after completing the above-mentioned process of perforation propulsion and chemical injection, the rod (G) is lowered again and the above-mentioned process of perforation propulsion and chemical liquid injection is repeated/or multiple times at the lower end of the ground improvement area. is also optional.

As described above, the present invention injects high-pressure water and/or air through the upper and lower ports provided at the lower end of the rod when the rod is propelled through the hole, so that the hole wall at the drilling point collapses and is forced onto the ground surface as slime. As a result, the diameter of the hole is enlarged compared to the conventional method, and the range of loosening of the hole wall increases.Next, when the rod is disseminated, the chemical liquid is injected at high pressure, so the injected chemical liquid expands. It is possible to effectively infiltrate the drilled holes and loosened hole wall portions, thereby significantly increasing the ground improvement capacity, and it is possible to provide a chemical injection method with high injection quality.

Therefore, the intended purpose can be achieved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a rod used in the construction method of the present invention, and FIGS. 2 to 4 are sectional views showing the construction steps of the construction method of the present invention. In the figure, (5) is the rod, ω) is the ground, (0) is the drilling, (
aγ is the hole wall, (D) is the ground improvement castle, (aχ is the inner passage, (
bl is the outer passage, (1) is the bit, (2) (4) is the cutting blade, (3) (6) is the nozzle, 00d is water, (a) is air, (ri is the chemical liquid. Patent applicant New Japan Techno Co., Ltd. Daiichiko

Claims (1)

[Claims] A rod having a drilling blade at the lower end and having an upper opening opening perpendicularly above the rod and a lower opening opening obliquely downward is used, and when the rod is driven to drill, water is removed from both the upper and lower ends. and/or rotating the rod without injecting high-pressure air, and rotating the rod without injecting high-pressure soil improvement chemicals from the upper and/or lower ports at the time of removing the rod after reaching a predetermined depth; A chemical injection method characterized by: