JP3255254B2 - Jet grouting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jet grouting method for forming a columnar compact in the ground to improve soft ground.

[0002]

2. Description of the Related Art First, a conventional jet grouting method will be described with reference to FIGS.

(1) Casing pipe setting process (FIG. 13) A casing pipe 2 is set on a boring machine 1 and pushed while rotating the casing pipe 2 so that drilling water is injected from a water injection hole 3 to form a metal crown at the tip. 4 to drill a guide hole A (FIG. 18) to form a casing pipe 2
Build.

(2) Triple pipe building process (FIG. 14).

A triple pipe 6 is built with a rough terrain crane 5.

(3) Step of Pulling Out Casing Pipe (FIG. 15) The casing pipe 2 is pulled out by the rough terrain crane 5.
In some cases, the casing pipe 2 may be pulled out to a predetermined depth and left.

(4) Jet grouting process (FIG. 1)
6) The triple pipe 6 is set on the jet machine 7, and the ultra high pressure water hose B, the compressed air hose C, and the solidified material hose D are connected to the triple pipe swivel 8 of the triple pipe 6. Then, the triple pipe 6 is rotated by the jet machine 7, and the triple pipe 6 is pulled up while jetting the jet E from the monitor 16 (FIG. 2) to perform jet grouting.

(5) Triple Tube Pulling Step (FIG. 17) When the formation of the columnar consolidated body F is completed in the jet grouting step, the triple pipe 6 is pulled up.

(6) Hole Filling Step (FIG. 18) The remaining guide hole A is filled back.

[0010]

In the conventional jet grouting method, a triple pipe must be added to form a columnar consolidated body at a large depth.

However, the addition of the triple pipe is very troublesome from the structural point of view, and the working efficiency is extremely poor.

An object of the present invention is to provide a jet grouting method for forming a columnar consolidated body at a large depth without adding a triple pipe.

[0013]

According to the jet grouting method of the present invention, a telescopic pipe consisting of a plurality of pipes mutually locked in the rotating direction is prepared, and a triple pipe is provided on the last pipe of the telescopic pipe. A pipe is provided to be locked in the rotation direction, a triple pipe swivel is provided at the upper end of the triple pipe, a drilling and water injection monitor is provided at the lower end, and a telescopic pipe in a state in which the entire pipe including the triple pipe is contracted is excavated. Set at the center, drill the ground by drilling and water injection while rotating the telescopic pipe, meanwhile extend the telescopic pipe and triple pipe in the meantime, and if the ground is drilled to a predetermined depth, create a columnar consolidated body It is supposed to.

Further, according to the jet grouting method of the present invention, a telescopic pipe comprising a plurality of pipes which are mutually locked in the rotating direction and whose final stage pipe is the largest in diameter is prepared. The pipe at the last stage of the pipe has a perforation with a triple pipe swivel at the top and a water injection monitor locked in the rotation direction, and the telescopic pipe with the pipe contracted is set at the center of the place to be excavated, and telescopic The ground is excavated by drilling and water injection while rotating the pipe, and during this time, the telescopic pipe is sequentially extended, and when the ground is excavated to a predetermined depth, a columnar consolidated body is formed.

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

Description of the operation and effect Since the drilling and water injection monitor is locked in the direction of rotation with respect to the telescopic pipe, the drilling and water injection monitor rotates directly or via a triple pipe. When the telescopic pipe is sequentially extended along with the excavation and the triple pipe is used, since the triple pipe is extended last, there is no need for a troublesome operation of adding the triple pipe. Therefore, work efficiency is improved.

In this case, the slime squirts onto the ground from a gap between the borehole and the telescopic pipe. After the construction, the ground improvement agent is ejected to fill the hole while raising the telescopic pipe.

According to the present invention, a columnar consolidated body can be formed in the ground without using a triple tube. That is, if a mechanism in which an injection nozzle is attached to the tip of a coiled tube is adopted as a means for injecting a ground improvement agent provided other than a telescopic pipe, first,
The telescopic pipe may be sequentially extended downward while rotating, excavation may be performed by the excavation means at the lower end, and then the processing may be performed by the above-described mechanism using the coiled tube.

[0023]

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

FIG. 1 shows an example of a triple pipe installation facility.

In FIG. 1, a cable 12 wound around a cable reel 11 of a crane truck 10 hangs down via a cable guide roller 13, and an end of the cable 12 has a triple pipe swivel of a triple pipe device P. 17 are suspended. The telescopic pipe 20 of the triple pipe device is held on the front frame 14 of the crane vehicle 10.

In FIGS. 2 to 4, at the lower end of the triple pipe 15 of the triple pipe device P, a drilling and water injection monitor 16 is provided, and at the upper end, a triple pipe swivel 17 is provided. 17 has an ultra-high pressure water hose B,
A compressed air hose C and a solidified material hose D are connected to each other.

The telescopic pipe 20 comprises an outer cylinder 1
A plurality of (three in the example shown in the figure, three circumferentially) intaglio portions a each comprising a stepped pipe 21 and an inner cylindrical two-stepped pipe 22.
Is locked in the rotation direction. And the triple tube 15
Is also a three-stage pipe, and is locked to the two-stage pipe 22 in the rotational direction by the above-mentioned intaglio portion a.

Next, an embodiment of forming the columnar compact F is shown in FIG.
This will be described with reference to FIG. Note that the lengths of the pipes 21 and 22 and the triple tube 15 in these drawings are shown smaller than those in FIG.

The center of the telescopic pipe 20 whose entire length is to be cut is set at the center of the place where the excavation is to be performed (FIG. 5).

Next, the ground is excavated by the drilling and water injection monitor 16 (FIG. 6). Then, the two-stage pipe 22 is extended, and the ground is further excavated by the drilling and water injection monitor 16 (FIG. 7).

When drilling is performed to a predetermined depth by the drilling and water injection monitor 16 (FIG. 8), FIGS.
By performing the same method as the conventional method shown in FIG. 1, a columnar consolidated body F is formed.

In other words, when the triple tube 6 in FIG. 14 is replaced with the triple tube device P of the present invention, about 3
The columnar consolidated body F can be formed at twice the depth without adding a triple tube.

Although not clearly shown in the embodiment of FIGS. 5-9, a drilling bit or the like is provided at the tip of the drilling and water injection monitor 16, and the telescopic pipe 20 is extended downward while rotating. Excavate the ground to the depth.

It is to be noted that a coiled tube provided with a ground improvement agent injection mechanism may be used instead of the triple tube 15 (not shown).

FIG. 9 shows another embodiment of a triple tube device embodying the present invention. In this triple tube device P1, the telescopic pipe 30 is such that the last stage pipe has the largest diameter. At the time of extension, the uppermost one-stage pipe 31,
It is composed of the next two-stage pipe 32 and the lowermost three-stage pipe 33 with a large diameter. In this example, a perforation and water injection monitor 34 is provided on the three-stage pipe 33 so as to be locked in the rotation direction. In this embodiment, the telescopic pipe 30 which has been contracted as a whole is aligned (FIG. 9), and the ground is excavated in the contracted state (FIG. 10). Excavation (FIG. 11), and excavation to a predetermined depth by the drilling and water injection monitor 34 (FIG. 1)
2).

Also in the embodiment shown in FIGS. 9-12, it is possible to form the columnar compact F. In addition, by using a coiled tube provided with a ground improvement agent injection mechanism (not shown), the triple tube 15 can be omitted.

[0037]

As described above, according to the present invention, since the rotation in the rotational direction is locked to the conventionally used triple pipe or telescopic pipe, it is possible to reach a large depth only by extending the telescopic pipe. Therefore, the troublesome work of adding and disconnecting a triple pipe as in the related art is eliminated, and workability is improved. Further, since each hose leading to the monitor is surrounded by the telescopic pipe, it is in a protected state, and troubles such as sticking do not occur.

In addition, since the construction is performed in various work forms based on the columnar solid to be formed, the characteristics of the work ground, and the like, good ground improvement is performed.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of a triple pipe building facility.

FIG. 2 is a side view showing one embodiment of the present invention.

FIG. 3 is a side sectional view of FIG. 2;

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a side sectional view showing the center alignment in the triple pipe building process.

FIG. 6 is a side sectional view showing a telescopic pipe inserted state.

FIG. 7 is a side sectional view showing a two-stage pipe extension state.

FIG. 8 is a side sectional view showing a triple pipe extension state.

FIG. 9 is a drawing corresponding to FIG. 5, showing another embodiment of the triple tube device.

FIG. 10 is a drawing corresponding to FIG. 6 of the embodiment.

FIG. 11 is a drawing corresponding to FIG. 7 of the embodiment.

FIG. 12 is a drawing corresponding to FIG. 8 of the embodiment.

FIG. 13 is a side sectional view for explaining a casing pipe embedding step of the conventional method.

FIG. 14 is a side sectional view for explaining a triple pipe building process.

FIG. 15 is a side sectional view illustrating a casing pipe drawing step.

FIG. 16 is a side sectional view illustrating a jet grouting process.

FIG. 17 is a side sectional view illustrating a triple tube drawing step.

FIG. 18 is a side sectional view illustrating a hole filling step.

[Explanation of symbols]

 A: Guide hole B: Ultra-high pressure water hose C: Compressed air hose D: Solidified material hose E: Jet F: Columnar consolidated body P, P1: Triple pipe device DESCRIPTION OF SYMBOLS 1 ... Boring machine 3 ... Water injection hole 4 ... Metal crown 5 ... Rough terrain crane 6 ... Triple pipe 7 ... Jet machine 8 ... Triple pipe swivel 10 ... Crane truck 11 ... Cable reel 12 ... Cable 13 ... Cable guide roller 14 ... Front frame 15 ... Triple tube 16 ... Monitor 17 ... Triple tube swivel 20, 30 ... Telescopic pipe 21 , 31 ... 1 stage pipe 22, 32 ... 2 stage pipe 33 ... 3 stage pipe

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Hiroshi Kotaki 1-6-4 Moto-Akasaka, Minato-ku, Tokyo Inside Chemical Grout Co., Ltd. (56) References JP-A-63-89722 (JP, A) 2-136131 (JP, U) Hikaru 1-156230 (JP, U)

Claims (2)

(57) [Claims] 1. A telescopic pipe comprising a plurality of pipes mutually locked in a rotating direction is prepared, and a triple pipe is provided in a final stage of the telescopic pipe so as to be locked in a rotating direction, and the triple pipe is provided. A triple pipe swivel is provided at the upper end of the pipe, and a drilling and water injection monitor is provided at the lower end. A jet grouting method, wherein a ground is excavated by a monitor, a telescopic pipe and a triple pipe are sequentially extended during the excavation, and a columnar consolidated body is formed when the ground is excavated to a predetermined depth. 2. A telescopic pipe comprising a plurality of pipes, each of which is mutually locked in a rotational direction and whose final stage pipe has the largest diameter, is prepared. The drilling and water injection monitor provided with a triple pipe swivel is locked in the rotation direction, the telescopic pipe in a state where the pipe is contracted is set at the center of the place to be excavated, and the drilling and water injection monitor is rotated while rotating the telescopic pipe. A jet grouting method, wherein the ground is excavated, telescopic pipes are sequentially extended during the excavation, and a columnar solidified body is formed when the ground is excavated to a predetermined depth.