JP3827394B2 - Cement milk injection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for injecting cement milk.
[0002]
[Prior art]
In a conventional method of injecting cement milk, rocks that allow water to pass through but do not allow cement particles to pass through, such as soft rocks, may become clogged rapidly when the flow rate decreases. This is because the cement particles in the cement milk settle in the injection path and block the path due to the decrease in the flow rate.
[0003]
The present invention was made to solve the conventional problems as described above, and injecting cement milk that can be injected under normal conditions even in a rock mass that allows water to pass through but prevents cement particles from passing through. It aims to provide a method.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the cement milk injection method of the present invention allows water to pass through, but is an injection method in a rock where it is difficult for cement particles to pass between the grout pump and the injection nozzle. By inserting a passage made of a flexible material, housing the flexible passage in an oil chamber, and applying a reciprocating motion of the piston to the pressurized oil in the oil chamber, the flexible passage is periodically formed. It is characterized by a cement milk injection method that is compressed and expanded .
[0005]
[Embodiments of the present invention]
Hereinafter, embodiments of the cement milk injection method of the present invention will be described with reference to the drawings.
[0006]
<I> Target rock mass.
As described above, the rock mass that is the subject of the injection method of the present invention is a rock mass that allows water to pass through like soft rock but difficult to pass cement particles.
[0007]
<B> Injection piping.
Cement and water are mixed by the agitator 1, pressurized by the grout pump 2, and injected from the injection nozzle to the ground via the controller 3.
Further, in the method of the present invention, a pulse application device 4 for applying a pulse by periodically pressurizing cement milk is interposed between the grout pump 2 and the injection nozzle.
[0008]
<C> Pulse application device 4.
The pulse applying device 4 interposed between the grout pump 2 and the injection nozzle is constituted by a flexible passage 41 made of a flexible material such as rubber.
The flexible passage 41 is accommodated in the oil chamber 42.
Further, a piston 43 is accommodated in a part of the oil chamber 42. The piston 43 is reciprocated through, for example, an electromagnetic valve. This reciprocating motion employs a frequency of about 100 times per minute, for example.
As the piston 43 reciprocates, the flexible passage 41 repeats compression and expansion through the pressurized oil in the oil chamber 42. As a result, a pulse is applied to the cement milk being injected.
[0009]
<D> Action of pulse.
When a pulse is applied to the cement milk, it is possible to forcibly excite cement particles to be settled by this pulse. This pulse is transmitted from the nozzle at the tip to the path during injection. This prevents the blockage that occurs in the injection path.
[0010]
[Effect of the present invention]
Since the cement milk injection method of the present invention is as described above, the following effects can be obtained.
<A> When the pulse application device 4 is operated when the injection amount decreases during the injection, the injection amount is recovered. As a result, the same injection amount can be continuously maintained for a long time.
<B> Not only when the injection amount is reduced, but by always giving pulses, a better injection effect can be expected.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of an embodiment of a method for injecting cement milk according to the present invention. FIG. 2 is an explanatory diagram of an embodiment of a pulse applying device used in the method of the present invention.

Claims (1)

It is an injection method in bedrock where water is passed but cement particles are difficult to pass between the grout pump and the injection nozzle.
Interposing a passage made of flexible material,
This flexible passage is stored in the oil chamber,
By applying a reciprocating motion of the piston to the pressurized oil in the oil chamber, the flexible passage is periodically compressed and expanded .
Cement milk injection method.

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