JPH11107267A - Jet grouting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a jet grouting method for constructing a solid body without making any air lock around an inclined excavated hole. SOLUTION: An excavated hole 1 is so bored that it is equipped with an inclination a to a vertical shaft, and a pipe 2 having a nozzle 3 for jetting a jet J downward at a slightly larger angle β than the inclination α to a radial outside and a rotary shaft right angled surface on the front end is inserted into the excavated hole 1. While jetting grout from the nozzle 3 to a specific distance from the lower part of the excavated hole 1, and the pipe 2 is pulled out while rotating it around the axial center to construct a solid body G in the ground.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for drilling a drilling hole in the ground, inserting a pipe provided with a nozzle for jetting a jet of high-pressure fluid radially outward into the drilling hole, and excavating from the nozzle. The present invention relates to a jet grouting method for injecting a working fluid (for example, drilling water) and a consolidating material, and pulling up a pipe while rotating (around a rotation axis of the pipe) to construct a consolidated body in the ground.

[0002]

2. Description of the Related Art The jet grouting method as described above is
Conventionally known. Here, depending on the place where such a jet grouting method is to be constructed, there is a buried object or the like in the surroundings, and it is necessary to perform the construction from the horizontal direction as shown in FIG. 7 or FIG. It is also necessary to carry out the construction as shown in the figure below. On the other hand, the applicant discloses a jet grouting method in which holes are drilled in the horizontal direction, for example, in Japanese Patent Application Laid-Open No. 8-302662. However, when the construction is performed in a horizontal or inclined manner, as shown in FIGS. Can be done. The existence of such a hollow portion causes problems such as the inability to counter the earth pressure and the possibility of collapse.

[0003]

SUMMARY OF THE INVENTION The present invention provides a jet grouting method capable of constructing a consolidated body without generating air pockets around a drilled hole drilled in a state inclined with respect to the vertical direction. It is an object.

[0004]

According to the jet grouting method of the present invention, a pipe provided with a nozzle for piercing a drilling hole in the ground and jetting a jet of a high-pressure fluid radially outward of the drilling hole is provided. In the jet grouting method of inserting and injecting drilling water and consolidation material from a nozzle while rotating the pipe to build a consolidated body in the ground, the drilling hole has an inclination angle with respect to a vertical axis. And jets the jet of the high-pressure fluid downward at an inclination angle slightly larger than the inclination angle with respect to a plane radially outward and perpendicular to the rotation axis of the pipe. Then, in a predetermined region of the drilling hole, a drilling fluid and a solidifying material are injected from the nozzle, and the pipe is rotated and pulled up to build a solidified body in the ground.

In the jet grouting method of the present invention, a drilling hole is drilled in the ground, and a pipe provided with a nozzle for ejecting a jet of a high-pressure fluid radially outward is inserted into the drilling hole. In a jet grouting method in which the pipe is rotated and pulled up to construct a consolidated body in the ground while injecting drilling water and consolidation material, the excavation hole is drilled in an aspect having an inclination angle with respect to a vertical axis. Then, a pipe having a first nozzle and a second nozzle is inserted into a borehole, and the first nozzle is slightly less than the inclined angle with respect to a plane radially outward and perpendicular to the rotation axis of the pipe. The second nozzle is provided below the first nozzle and at a predetermined position paired with the first nozzle, and the second nozzle is jetted from the first nozzle. Ejects a jet that intersects The first and second nozzles inject a drilling fluid and a consolidated material in a predetermined area of the borehole, and pull up while rotating the pipe to build a consolidated body in the ground. I have.

In practicing the present invention, it is preferable that the angle formed between the plane perpendicular to the rotation axis and the nozzle jet is as close as possible to the inclination angle.

According to the present invention having the above-described structure, the high-pressure fluid is ejected in a conical shape from the nozzle of the rotating pipe, and the conical surface of the high-pressure fluid is slightly raised upward with respect to the borehole even at the uppermost position. There is a slope, along the slope,
The air or slime is discharged to the outside through the borehole without collecting at the uppermost position. Therefore, the underground consolidated body can be built by performing the jet grouting method around the central axis of the excavation hole inclined with respect to the vertical direction. Therefore, it is possible to construct an underground solid body in a narrow area or an area where restrictions such as avoiding buried objects exist.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, an excavation hole 1 is drilled from the ground surface GL into the ground at an inclination angle α with respect to a vertical axis. A plurality of nozzles 3 are provided at the tip of a pipe 2 inserted into the excavation hole 1, and the injection direction of the nozzles 3 is directed outward in the radial direction and with respect to the plane perpendicular to the rotation axis XX. It is provided downward at an angle β slightly larger than the inclination angle α by an angle γ.

In the construction of the consolidated body by the jet grouting method, first, a drilling hole 1 is drilled to a predetermined depth at an inclination angle α, and a pipe 2 is inserted. Then, drilling water, solidified material, and compressed air are respectively ejected from the nozzle 3 at the tip of the pipe as a high-pressure jet J, and at the same time, the pipe 2 is pulled up by a predetermined length while rotating about its axis. Accordingly, the consolidated body G having a predetermined length is formed by the consolidating material ejected conically by the rotation of the nozzle 3.

At this time, as shown in FIG. 3, the upper conical surface is inclined downward by an angle γ (see FIGS. 2 and 3) from a horizontal plane (indicated by reference numeral LUG in FIG. 3) even at the uppermost portion. . Therefore, the air or the slime is easily discharged from the borehole 1 along the slope as shown by a plurality of arrows SA in FIG. As a result, no air pool like the area indicated by the symbol A in FIG. 7 or FIG. 8 is generated.

Next, in the embodiment shown in FIG.
A is provided with two nozzles indicated by reference numerals 3 and 4. The upper first nozzle 3 jets downward at an angle β slightly larger than the inclination angle α as in the previous embodiment.
A jet nozzle is provided so as to jet a jet nozzle 1, and a lower second nozzle 4 is provided in a pair with the first nozzle 3 so that the jet J2 intersects the jet J1 at a predetermined position. Is provided with a nozzle.

In this embodiment, the jets J1 and J2 of the first and second nozzles 3 and 4 are cross jets that cross or collide at predetermined positions. In this cross jet, it has been experimentally confirmed that the excavation force does not act outward in the radial direction from the position where the jets intersect (or collide). Thus, the radial dimension excavated by the jet is very accurately controlled.

According to the embodiment shown in FIG. 4, the radial dimension is extremely precisely controlled, and is excavated into a cylindrical shape, and the consolidation material is injected so that the radial dimension is extremely precisely controlled. The union G is built. Therefore, it is suitable for construction with restrictions such as when there is a buried object.

FIGS. 5 and 6 show an embodiment in which cylindrical compacts G1,... Are continuously constructed by the above-described method. As a result of continuously constructing the plurality of compacts G1,..., It is possible to construct a compact parallel (or substantially parallel) to the ground surface GL.

[0015]

According to the present invention constructed as described above, air or slime is discharged without stagnation and a cavity is prevented from being formed even when the drilling hole is constructed at an angle. Is done. Therefore, it is not possible to withstand the earth pressure, and it is possible to construct a horizontal or inclined underground solid body without fear of forming a hollow portion causing a depression.

As a result, it is possible to construct a consolidated body in a narrow area or in a place where there is a restriction such as avoiding a buried object.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a view for explaining an injection direction in FIG. 1;

FIG. 3 is a sectional view showing a state where air or slime is discharged in the embodiment of FIG. 1;

FIG. 4 is a cross-sectional view showing another embodiment of the present invention.

FIG. 5 is a cross-sectional view showing an example in which a consolidated body is continuously built by the jet grouting method of the present invention.

FIG. 6 is a plan view of FIG. 4;

FIG. 7 is a cross-sectional view showing a case where a conventional jet grouting method is constructed in a horizontal direction.

FIG. 8 is a cross-sectional view showing a case where a conventional jet grouting method is performed with an axis inclined.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Drilling hole 2 ... Pipe 3 ... Nozzle G ... Solidified body J ... Jet

Claims (2)

[Claims] 1. A drilling hole is drilled in the ground, and a pipe provided with a nozzle for jetting a jet of high-pressure fluid is inserted radially outward of the drilling hole. Drilling water and solidified material are discharged from the nozzle. In the jet grouting method, in which the pipe is rotated and pulled up while rotating to build a consolidated body in the ground, the drilling hole is pierced at an angle with respect to a vertical axis, and the jet of the high-pressure fluid is jetted. Is ejected downward with an inclination angle slightly larger than the inclination angle with respect to a plane that is radially outward and perpendicular to the rotation axis of the pipe, and from the nozzle in a predetermined region of the drilling hole. A jet grouting method characterized by injecting a drilling fluid and a consolidating material and building up a consolidated body underground by rotating and pulling up a pipe. 2. A drilling hole is drilled in the ground, and a pipe provided with a nozzle for jetting a jet of high-pressure fluid radially outward is inserted into the drilling hole, and drilling water and consolidated material are discharged from the nozzle. In the jet grouting method in which the pipe is rotated and pulled up while rotating to build a consolidated body in the ground, the drilling hole is pierced at an angle with respect to a vertical axis, and the first nozzle and A pipe having a second nozzle is inserted into the borehole, and the first nozzle is jetted radially outward and downward at an angle slightly greater than the inclination angle with respect to a plane perpendicular to the rotation axis of the pipe. And the second nozzle is provided at a predetermined position below the first nozzle and in a pair with the first nozzle, and ejects a jet that intersects with the jet ejected from the first nozzle. Is configured in the same way A jet grouting method characterized by injecting a drilling fluid and a consolidating material from first and second nozzles in a region, and pulling up while rotating a pipe to build a consolidated body in the ground.