JP3663503B2 - High pressure injection ground improvement method - Google Patents

Description

[0001]
The present invention is suitable for high pressure spray ground improvement method, more specifically, for constructing an improved body in the ground to be improved, for construction where there is an obstacle layer such as a rubble layer or hard layer in the ground to be improved or underwater construction. about the high-pressure injection ground improvement construction method was.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a high pressure spray ground improvement method has been widely used in which an improved body is created while a hardening material liquid is sprayed from a spray nozzle into a ground to be improved at a high pressure while rotating an injection rod up and down to improve the ground.
This high-pressure spray ground improvement method, when there is an obstacle layer such as a rubble layer or hard layer in the upper part of the ground to be improved or in the ground, pre-drilling using a rotary percussion drill etc. in advance, Usually, an injection rod is installed in the borehole.
[0003]
[Problems to be solved by the invention]
However, the conventional method has the following problems.
Chi words, in accordance come method, ▲ 1 ▼ prior drilling, ▲ 2 ▼ pulling the inner tube, ▲ 3 ▼ injection rod like an anchor, ▲ 4 ▼ casing withdrawal, ▲ 5 ▼ various steps of the injection Construction of hardener solution This requires a lot of effort and time.
[0004]
Moreover, in the construction when the planned ground for improvement is underwater, the location of the preceding excavation hole is below the surface of the water, so that the protection and position confirmation of the preceding excavation hole are complicated and difficult.
[0005]
[Means for Solving the Problems]
The present invention has the following configuration in order to solve the above-described problems.
High-pressure spray ground improvement method to improve the ground by rotating the shaft body up and down and spraying the hardened material liquid into the ground to be improved from the spray nozzle of the hard material spray monitor provided at the lower end of the shaft body. A down-the-hole hammer is attached to the hardened material liquid injection monitor provided at the lower end of the shaft body of the injection rod used for cutting, and only the compressed air is discharged from the injection nozzle to the soft soil layer in the ground to be improved. When the drilling hole touches an obstacle layer such as a rubble layer or hard layer in the ground to be improved, the obstacle layer is blown and drilled to the predetermined depth with the down-the-hole hammer, and then the injection rod is rotated. High pressure to create an improved body by a series of steps consisting only of two steps of drilling and hardening material liquid injection formation, which is a standard high pressure injection process, by high pressure injection of the hardening material liquid from the monitor for injection of the hardening material liquid while pulling up. Injection ground It is that it was a good method.
[0006]
The construction method of the present invention is such that a down-the-hole hammer equipped at the tip of the injection rod curing agent liquid injection monitor is blown to a predetermined depth, and then the injection rod is rotated and the injection rod is injected with a high pressure from the injection nozzle. On the other hand, since the improved body is created in the ground to be improved, it was necessary to improve the ground by using the high-pressure injection method for the ground including the conventional obstacle layer. (1) Advance drilling, (2) Pull out the inner pipe, 3) Injection rod installation, (4) Casing drawing, (5) Hardening material injection process are standard high-pressure injection processes (1) Drilling and (2) Hardening material injection It is possible to create an improved body in the ground to be improved by only two steps of creation.
[0007]
As described above, since the construction method of the present invention is a construction method consisting of only two steps of drilling and injection of a hardening material liquid, the construction period can be shortened and construction labor can be saved, which is very economical. Is.
In addition, even in the case of underwater construction when the ground to be improved is underwater, the drilling and injection creation process can be performed continuously, so that it is not necessary to protect and confirm the position of the preceding excavation hole as in the conventional construction method.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a high pressure spray ground improvement method and apparatus according to the present invention will be described with reference to the drawings.
FIG. 1 is an enlarged schematic cross-sectional view of the main part of the injection rod of the present invention, and FIG. 2 is an explanatory view showing the construction procedure of the present invention.
As shown in FIG. 1, an injection rod 1 used in the method of the present invention includes an outer tube 2 that forms an air flow path 2 a inside a shaft body 1 a supported by a drive device (not shown), and a hardening material liquid. It forms in the double tube structure of the inner tube 3 which comprises the flow path 3a.
Further, a hardening material liquid injection monitor 4 is attached to the lower end portion of the shaft body 1 a of the injection rod 1 by a screw joint 7.
[0009]
The curable material liquid injection monitor 4 has a curable material liquid flow path 4b communicating with the curable material liquid flow path 3a in the shaft body 1a of the double tube structure of the injection rod 1, and is supplied from the flow path 4b. It has the hardening material liquid injection nozzle 6 which injects the hardening material liquid B to be performed, and has an air flow path 4a communicating with the air flow path 2a of the shaft body 1a.
[0010]
The down-the-hole hammer 5 is attached to the lower part of the curing material liquid jet monitor 4 configured as described above, and the down-the-hole hammer 5 is operated by the compressed air A from the air flow path 4a of the curing material liquid jet monitor 4.
[0011]
The injection rod configured as described above is set at the planned drilling position of the ground to be improved and drilled. However, as shown in FIG. When it touches the obstacle layer D such as a hard layer below the top soil C of the ground to be improved, the obstacle layer D such as the hard layer is hit by the down-the-hole hammer 5 provided at the tip of the spray monitor 4. To drill and drill holes.
[0012]
Next, the soil rod E to be improved is penetrated through the injection rod 1 to a predetermined depth while only the compressed air A from the air flow path 4a of the hardener liquid jetting monitor 4 is discharged from the tip of the down-the-hole hammer 5 (see (b) in FIG. )).
After penetration to a predetermined depth is completed, urchin by are shown in FIG. 2 (c), further performs Yohori (F).
[0013]
After drilling to a predetermined depth, as shown in FIG. 2C, the curing material liquid B is injected from the injection nozzle 6 of the injection monitor 4, and the injection rod 1 is inserted as shown in FIG. The improved body G is created while rotating up.
When the curing material liquid B is sprayed to a predetermined depth and the formation of the improved body G is completed, the injection of the curing material liquid B is stopped as shown in FIG. The improved body G is created.
[0014]
【The invention's effect】
As a result of carrying out the construction method of the present invention, even if there is an obstacle layer such as a hard layer or a rubble layer in the ground to be improved, the obstacle layer can be easily drilled, compared with the prior art. The construction period was greatly shortened and a great economic effect was obtained.
[0015]
In addition, even underwater construction results, it is possible to easily drill holes in the bottom of the sea such as rubble layers, without needing to protect and confirm the position of the drilling holes, and to perform smooth construction, which is the same as construction on the ground. The effect was able to be acquired.
[Brief description of the drawings]
FIG. 1 is an enlarged schematic cross-sectional view of a main part of an injection rod according to the present invention.
FIG. 2 is an explanatory view showing a construction procedure of the present invention.
[Explanation of symbols]
1 injection rod 2 outer tube 2a air channel 3 inner tube 3a hardener liquid channel 4 cured material liquid jetting monitor 4a air passage 4b hardener liquid channel 5 down-the-hole hammer 6 injection nozzle 7 screw joints A compressed air B Hardening fluid C Topsoil D of improved ground D Obstacle layer E Improved ground layer F Yobori G Improved body

Claims (1)

High-pressure spray ground improvement method to improve the ground by rotating the shaft body up and down and spraying the hardened material liquid into the ground to be improved from the spray nozzle of the hard material spray monitor provided at the lower end of the shaft body. A down-the-hole hammer is attached to the hardened material liquid injection monitor provided at the lower end of the shaft body of the injection rod used for cutting, and only the compressed air is discharged from the injection nozzle to the soft soil layer in the ground to be improved. When the drilling hole touches an obstacle layer such as a rubble layer or hard layer in the ground to be improved, the obstacle layer is blown and drilled to the predetermined depth with the down-the-hole hammer, and then the injection rod is rotated. The improvement material is created by a series of steps consisting only of two steps of drilling and hardening material liquid injection, which are standard high pressure injection processes, by high pressure injection of the hardening material liquid from the monitor for injection of the hardening material liquid while pulling up. With features High-pressure injection ground improvement method that.

Images