JPH0119485B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chemical injection device for civil engineering used in a method of injecting chemical liquid to strengthen soft ground.

In civil engineering work such as tunnel construction, when the ground is soft, a chemical solution is injected into the ground before excavation work begins in order to prevent accidents such as cave-ins and to make the excavation work easier. It is normal to perform excavation work after the ground has hardened, and the work of injecting the chemical solution is generally performed by boring several locations in the ground where the chemical solution is to be injected, inserting casing pipes, and then After inserting the chemical liquid injection pipe into the casing pipe and sealing the gap between the ends of the chemical liquid injection pipe, a chemical liquid injection machine is set, and the chemical liquid such as cement milk, water glass, etc. is force-fed into the chemical liquid injection pipe by the press-fitting machine. The chemical solution is then injected into the ground from the tip of the injection pipe and hardened, thereby hardening and strengthening the ground.

Conventionally, the chemical injection pipes used in the above chemical injection work include steel pipes, synthetic resin pipes,
Glass tubes, etc. are bonded together, but when inserting the tube after boring, if there is a protrusion in the borehole, it may get caught on the protrusion, or the joint of the drug solution injection tube may get caught on the protrusion. It was difficult to do the work efficiently because the work took a long time because the work could get stuck and become stuck.

The present invention has been made for the purpose of providing a chemical liquid injection device that can solve the problems of the prior art as described above. A chemical liquid injection guide tube with a chemical liquid injection tube with its tip sealed in a folded state is inserted into the casing pipe inserted into the hole, and the gap between the borehole or the casing pipe and the chemical liquid injection guide tube is sealed with a packer. When a chemical solution is injected into the chemical solution injection guide tube, the chemical solution injection tube stretches and moves forward due to the injection pressure of the chemical solution, and the tip of the tube reaches the tip of the borehole, increasing the pressure inside the tube. For example, the seal at the tip of the tube is broken, allowing the chemical solution to be injected into the ground.

Next, an example of implementation of the present invention will be explained with reference to the drawings.

G is the ground where the chemical solution is to be injected, B is the bore hole provided in the ground G, 1 is the casing pipe inserted into the bore hole B, 2 is the chemical solution injection guide pipe, 3
4 is a chemical injection tube whose tip is sealed 3a;
and 5 is a packer, in which a cushioning protrusion 1a is appropriately formed on the inner surface of the casing pipe 1, and a chemical liquid injection guide tube 2 is provided with a flange-like head 2a at its tip and fins 2b for rectification. The drug solution injection tube 3 is fitted in a folded state, and the rear end of the tube is fixed 3b to the rear part of the drug solution injection guide tube 2, and the drug solution injection guide tube 2 is inserted into the casing pipe, and the casing pipe 1 is inserted into the drug solution injection guide tube 2. The gap created at the rear end of the drug solution injection guide tube 2 is sealed by packers 4 and 5.

As shown in the figure, the apparatus according to one example of the present invention is configured as shown in FIG. When a drug solution is pressurized into the injection guide tube 2, the drug solution passes through the guide tube 2, is forced out from the tip, and moves forward while pressing the drug solution injection tube 3. At this time, the tube 3 The folded portion gradually expands and receives the chemical liquid therein, and when the seal 3a at the tip reaches the tip of the borehole B and the pressure inside the tube 3 increases, the tube 3 expands in the circumferential direction. Tube 3 is in close contact with the ground around the outer periphery of borehole B.
When the internal pressure exceeds a certain pressure value, the seal 3a etc. will break and the injection of the chemical into the ground G will start, and cracks or soft ground may occur in the middle part of the borehole B. If there is a problem, the tube 3 corresponding to the crack or soft ground will break and the chemical will leak out, and the chemical will be injected into the crack or the soft ground. The buffer protrusion 1a appropriately formed on the inner surface allows the tube 3 to contact the inner wall of the casing pipe 1 and the head 2a and fin 2 of the chemical solution injection guide tube 2 when the chemical solution injection tube 3 is extended.
The head 2 provided at the tip of the chemical injection guide tube 2 is useful for preventing damage caused by contact with the chemical liquid injection guide tube 2.
a and the fins 2b prevent backflow of the chemical solution, and
This is useful for smooth running of the drug solution injection tube 3 when the drug solution injection tube 3 is extended.

In addition, in the above embodiment, the chemical liquid injection guide tube 2
Casing pipe 1 inserted into borehole B
Although the case has been described in which the liquid injection guide tube 2 is inserted into the bore hole B, the present invention is not limited to this, and the chemical solution injection guide tube 2 may be directly inserted into the bore hole B.

In the chemical injection work using the device of the present invention, a chemical liquid injection guide tube and a soft chemical liquid injection tube are used instead of conventional chemical liquid injection tubes such as steel pipes or synthetic resin pipes, and the tube is attached to the guide tube in a folded state. Then, when a chemical liquid is pressurized into the guide tube, the chemical liquid flows into the tube,
The tube expands to move on its own due to the injection pressure of the chemical solution, and when the tip of the tube reaches the tip of the borehole and the pressure inside the tube increases, the tube expands in the circumferential direction and ends. Because the chemical liquid is injected into the ground by bursting, it not only makes the chemical injection work extremely efficient, but also works well for cracks, etc. where conventional chemical injection devices could not inject enough chemical liquid. Can be injected.

Therefore, the chemical liquid injection device of the present invention is suitable as a chemical liquid injection device used for injecting chemical liquid into soft ground to strengthen the ground prior to construction work such as a tunnel.

[Brief explanation of drawings]

The figure is a longitudinal sectional side view of an example of implementation of the present invention. G...Ground, B...Borehole, 1...Casing pipe, 2...Chemical solution injection guide pipe, 3...Chemical solution injection tube, 4, 5...Pack car.

Claims (1)

[Scope of Claims] 1. A chemical liquid injection guide tube, in which a chemical liquid injection tube with a sealed tip is fitted in a folded state, is inserted into a bore hole provided in the ground where a chemical liquid is to be injected, and the chemical liquid is connected to the bore hole. When the gap in the injection guide tube is sealed with a packer and a chemical solution is injected into the chemical solution injection guide tube, the drug solution injection tube stretches and moves forward due to the injection pressure of the drug solution, and the tip of the tube reaches the tip of the borehole. When the pressure inside the tube increases, the seal at the tip of the tube ruptures.
A chemical liquid injection device for civil engineering, characterized in that a chemical liquid is injected into the ground. 2. Insert a chemical injection guide tube with a chemical injection tube with its tip sealed in a folded state into a casing pipe inserted into a bore hole provided in the ground where the chemical liquid is to be injected, and then insert the chemical liquid injection guide tube into the casing pipe and the chemical liquid injection tube. When the gap in the guide tube is sealed with a packer and a chemical solution is injected into the chemical solution injection guide tube, the chemical solution injection tube stretches and moves forward due to the injection pressure of the chemical solution, and the tip of the tube reaches the tip of the borehole. 1. A chemical liquid injection device for civil engineering, characterized in that when the pressure inside the tube increases, the seal at the tip of the tube breaks and the chemical liquid is injected into the ground.