JP3217765B2 - Ground improvement 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 ground improvement method for forming an underground formation by inserting an injection pipe into a target ground, injecting a hardening material at a high pressure, and mixing the hardening material into the ground. The creation of an underground formation is also effective as a countermeasure against ground liquefaction due to an earthquake.

[0002]

2. Description of the Related Art Conventionally, as a ground improvement method for forming an underground formation by inserting an injection pipe into a target ground, injecting a hardening material at a high pressure and mixing a hardening material, a CCP method, a JSG method or a CJG method, etc. There is. In any of the methods, the hardening material was injected at a high pressure from the injection nozzle at the lower end of the injection pipe while rotating the injection pipe to ascend, thereby forming a columnar hardening material-containing layer.

[0003]

According to the above-mentioned conventional method of forming an underground formation, a hardening material is injected at a high pressure from an injection nozzle at the lower end of the injection pipe while rotating the injection pipe, and the hardened material having a cylindrical shape is mixed. Because it is a mechanism to create a layer, when improving the ground in a certain range, the overlapping part and the unnecessary part need to be created to connect the columnar hardened material mixed layer, so the cost of construction is also expensive. However, it was not suitable for extensive ground improvement.

[0004] Also, when creating an underground formation, the conventional method of forming an underground formation is not economical because the overlapping portion and the unnecessary portion for connection are extremely wasteful at the time of connection. For this reason, there is a long-awaited need for a method of forming an underground wall that can be used at a low cost for underground wall for widespread improvement and liquefaction prevention.

[0005]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention aims to improve the quality of underground formations, increase the size of the underground formations, reduce the number of construction steps, and reduce costs. In a ground improvement preparation method in which an injection pipe is inserted into the ground, a hardening material is injected at a high pressure, and the hardening material is mixed into the ground to form an underground formation, a holding body is rotatably provided at the lower end of the injection pipe. An injection nozzle that slides and moves the holder is provided in the tangential direction of the injection pipe, and after inserting the injection pipe, the holder is set to be horizontal and the injection nozzle is slid to move the injection nozzle while the hardening material is moved. Injection was performed at a high pressure from an injection nozzle, an injection pipe was pulled out, and a ground improvement preparation method in which an underground formation in which a hardening material was mixed into the ground was formed.

Further, the present invention is to insert an injection pipe into the target ground to reduce the hardening material in order to improve the formation quality of the underground formation, increase the size of the underground formation, reduce the number of construction steps, and reduce the cost. In a ground improvement method for forming an underground formation by mixing a hardening material into the ground by injecting at a high pressure, a holder is rotatably provided at a lower end of an injection pipe, and an injection nozzle is provided at a tip of the holder. After the injection pipe is inserted, the injection pipe is inserted, then the injection nozzle is moved to the left and right, and the hardening material is injected from the injection nozzle at high pressure while moving the injection nozzle to the right and left, and the injection pipe is pulled out to the ground. A ground improvement preparation method for forming an underground formation containing a hardening material was adopted.

Further, in the present invention, the holder is provided with a cutting blade in order to facilitate movement of the holder.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail below with reference to the accompanying drawings, in which: FIG. In FIG. 1, a holding body 22 is rotatably provided below the injection tube 21. This holder 22
The holder 22 is rotated by a hydraulic cylinder, a wire, or a chain housed inside the injection pipe 21 to make it horizontal as shown in FIG. The hardening material such as cement milk is supplied to the injection nozzle by a hose 25 extending from the lower end of the injection pipe 21.

A moving body 24 is slidably provided on a holding body 22 as shown in FIG. 3, and an injection nozzle 23 is directed to the moving body 24 in a tangential direction of the injection pipe 21. The moving body 24 slides on the holding body 22 and injects a hardening material toward the ground at a high pressure from an injection nozzle 23 thereof. The moving body 24 moves from one end of the holding body 22 to the other end, and the injection pipe 2
1 is slightly pulled out and stopped, and similarly moved from the other end to one end, an underground formation in which a hardening material is mixed into the ground is formed.

As shown in FIG. 4, the apparatus used in the ground improvement preparation method of the present invention is provided with a holder 2 rotatably at the lower end of an injection pipe 1 and an injection nozzle 3 at the tip of the holder 2. Are provided in the tangential direction of the injection tube 1. The rotation of the holder 2 with respect to the injection pipe 1 is performed using a hydraulic pipe or the like housed in the injection pipe 1. As shown in FIG. 5, the holding body 2 is a sliding cylinder 1 having an injection nozzle 3 at the tip in a housing 11.
2 and a hydraulic cylinder 13 for driving the sliding cylinder 12.

A cutting blade 14 is fixed to the distal end surface of the sliding cylinder 12, and the guide cylinder 12 is fixed to the distal end of a piston rod 15 of the hydraulic cylinder 13 and slides as the piston rod 15 of the hydraulic cylinder 13 expands and contracts. The cylinder 12 and the injection nozzle 3 are movable forward and backward. A hardening material C such as cement milk is guided into the housing 11 by an introduction pipe 16. Sign 1
7 is a piston and 18 is a packing.

Here, the hardening material C is guided into the housing 11 from the introduction pipe 16, and the hardening material C is injected from the injection nozzle 3 into the ground at a high pressure. The injection direction of the hardening material C is the injection pipe 1
Are ejected in the tangential direction of FIG. At the same time, when the piston rod 15 of the hydraulic cylinder 13 is retracted, a surface in which the hardening material C is mixed into the ground is formed. When the piston rod 15 reaches the end, the injection pipe 1 is rotated by 180 °, and when the same operation is performed, a surface in which the hardening material C is mixed into the ground is formed on both sides of the injection pipe 1. Then, when the injection pipe 1 is pulled out step by step and the hardening material C is injected, the underground formation W is formed. When a long underground formation W is formed, the underground formation W may be formed adjacent to the formed underground formation W. When the injection pipe 1 rises, the ground is cut by the cutting blades 14 so that the holding body 2 can be easily raised.

In the above description, the example in which the injection nozzle 3 is provided at one end of the holder 2 has been described. However, the injection nozzle 3 may be provided at both ends of the holder. Further, the same components as described above can be provided on the opposite side at the same time. The method for forming an underground formation according to the present invention will be described in more detail. First, FIG.
The underground pipe 1 is erected on the target ground as shown in FIG. In this case, depending on the ground, there are a case where the injection pipe 1 is erected after drilling holes in advance and a case where the injection pipe 1 is erected immediately on the ground.

Next, as shown in FIG.
Is horizontal to the injection tube 1. Then, FIG. 6 (c)
As shown in the figure, the hardening material C is sprayed from the spray nozzle 3 toward the ground, and the injection pipe 1 is pulled out step by step.
The underground formation W mixed with is formed. Further, when connecting the underground formation W to the underground formation W, as shown in a plan view in FIG. 6D, the injection pipe 1 is pulled out, and the underground pipe 1 is inserted into an adjacent part. Formed and connected.

[0015]

As described above, the present invention relates to a soil improvement method in which an injection pipe is inserted into a target ground, a hardening material is injected at a high pressure, and the hardening material is mixed into the ground to form an underground formation. The holder is rotatably provided at the lower end of the injection pipe, and an injection nozzle that slides and moves the holder is provided in the tangential direction of the injection pipe. As the ground improvement method was adopted, the hardening material was injected at high pressure from the injection nozzle while sliding the nozzle to move the injection nozzle position, and the injection pipe was pulled out to create an underground formation in which the hardening material was mixed into the ground. The construction quality of the medium-sized compact can be improved, the size can be increased, the number of construction steps can be reduced, and the cost can be reduced.

The present invention also relates to a method for improving the ground in which an injection pipe is inserted into a target ground, a hardening material is injected at a high pressure, and the hardening material is mixed into the ground to form an underground formation. The holder is rotatably provided in the section, the injection nozzle is provided at the tip of the holder in the tangential direction of the injection pipe, and after inserting the injection pipe, the holder is horizontal and the injection nozzle is moved right and left to move the injection nozzle position. This is a ground improvement method where the hardening material is injected from the injection nozzle at high pressure while moving, and the injection pipe is pulled out to create an underground formation where the hardening material is mixed into the ground, so the width of the underground formation is accurately formed it can.

Furthermore, according to the present invention, the holding body is moved forward and backward linearly to the left and right instead of swinging motion, and the injection nozzle moves at a constant speed, so that the quality of the underground formation is improved. Furthermore, in the present invention, the movement of the holder is also a linear movement, the configuration is simple, the size can be increased, the number of construction steps can be reduced, and the cost can be reduced. Further, in the present invention, since the cutting blade is provided on the holder, cutting for moving the holder can be reliably performed in advance.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an outline of an injection tube of the present invention.

FIG. 2 is a schematic view showing an outline of an injection tube and a holder according to the present invention.

FIG. 3 is a schematic diagram illustrating a relationship between a holder and an injection nozzle according to the present invention.

FIG. 4 is a schematic view showing an outline of an injection tube of the present invention.

FIG. 5 is a schematic view showing an outline of an injection tube and a holder according to the present invention.

FIG. 6 is a view for explaining the ground improvement preparation method of the present invention, and FIG. 3 (a) is a schematic view showing a state where an injection pipe is erected. FIG. 6B is a schematic diagram showing a state in which the holder is horizontal with respect to the injection tube. FIG. 6 (c) is a schematic perspective view of forming an underground formation by injecting a hardening material. FIG. 6D is a schematic plan view showing a state in which the underground structures are continuously provided.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Injection pipe 2 ... Holder 3 ... Injection nozzle 11 ... Housing 12 ... Sliding cylinder 13 ... Hydraulic cylinder 14 ... Cutting blade 15 ... Piston rod 16 ... Introductory pipe 17 ... Piston 18 ... Packing 21 ... Injection pipe 22 ... Holder 23 ... injection nozzle 24 ... moving body 25 ... hose

Continuation of the front page (56) References JP-A-10-182283 (JP, A) JP-A-9-217338 (JP, A) JP-A-51-241515 (JP, A) JP-A-5-272125 (JP, A) JP-A-62-29611 (JP, A) JP-A-1-278614 (JP, A) JP-A-50-106411 (JP, A) JP-A-9-296439 (JP, A) 8-134889 (JP, A) JP-A-1-198916 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E02D 3/12 102

Claims (3)

(57) [Claims] 1. A ground improvement method in which an injection pipe is inserted into a target ground, a hardening material is injected at a high pressure and a hardening material is mixed into the ground to form an underground formation, and a holding body is provided at a lower end of the injection pipe. Is provided rotatably, an injection nozzle that slides and moves the holder is provided in the tangential direction of the injection pipe, and after inserting the injection pipe, the injection nozzle is slid by holding the holder horizontally and sliding the injection nozzle. A ground improvement method in which a hardening material is injected from an injection nozzle at a high pressure while being moved, an injection pipe is pulled out, and an underground formation in which the hardening material is mixed in the ground is formed. 2. A ground improvement method in which an injection pipe is inserted into a target ground and a hardening material is injected at a high pressure to mix the hardening material into the ground to form an underground formation, and a holding body is provided at a lower end of the injection pipe. The injection nozzle is provided at the tip of the holder in the tangential direction of the injection pipe, and after inserting the injection pipe, the holder is horizontal and the injection nozzle advances and retreats from side to side to cure while moving the injection nozzle position. A ground improvement method in which a material is injected from an injection nozzle at high pressure, an injection pipe is pulled out, and an underground formation in which a hardening material is mixed in the ground is created. 3. The method of claim 1, wherein the injection pipe is provided with a cutting blade.