JPS5830966B2 - Chemical injection method - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a chemical injection method that reduces the water permeability of the ground and increases the strength of the ground by pressurizing the injection material into the ground through an injection pipe inserted into the ground. be.

Recently, this type of chemical solution method involves injecting a so-called instant-setting gelling material (hereinafter referred to as the instant-setting gelling method), which takes only a few seconds to gel (hereinafter referred to as gelling time). In addition, a method of injecting a so-called long-lasting gelling material (hereinafter referred to as a long-lasting gelling method), which takes 10 to 50 minutes for gelling, is used.

However, all of these construction methods have drawbacks in terms of economy and workability.

In other words, with the instant-setting gelation method, the holes treated by this method will be piled up with the same number of lumps as the number of injections, and although it can be expected to increase the strength of the ground, it will not be able to stop water. In addition, there is a risk that the two chemicals being mixed may be mixed unevenly, resulting in areas that are slow to gel, and this may flow into the ground. Since the amount is limited to a small amount, for example around 101, there are drawbacks such as a long overall injection time.

In addition, the long-head type gelling method is commonly known as the double parakani method, but the steps up to injecting the chemical solution are complex and time-consuming, and the injection pipe becomes buried. Therefore, there was a drawback that it required additional costs.

The object of the present invention is to provide a method that can eliminate the drawbacks of the conventional chemical injection method as described above.

The invention will be described with reference to embodiments shown in the drawings.

1 to 5 are schematic diagrams for explaining the present invention in detail, and FIGS. 1 to 3 correspond to the 1st to 3rd steps, respectively, and FIG. Indicates the state in which

In the drawing, the injection device 3 is a double pipe consisting of an inner and outer pipe 45, and a digging blade 6 is provided at the tip of the injection device 3. As shown in FIG. While supplying polling water to the passage 9 in the inner pipe 4 as shown by the arrow, the hole 2 is excavated in the same manner as a normal excavation method.

Here, as shown in FIG.
The gelling material in the inner tube 4 is poured out at the bottom into the outer tube 5, where the art materials are mixed and the instant-setting gelling material is poured out from the outer tube 5 as shown by the arrow. It is poured toward the pore wall, forming a packer 1 in the pore space around it, and this portion separates the pore wall into upper and lower parts.

Thereafter, as shown in FIG. 3, the bottom opening of the inner tube 4 is opened and the long-lasting gelling material is supplied to the hole bottom through the inner tube 4 as shown by the arrow in FIG. The gelling material is supplied and injected into the hole wall, forming a gelling layer 8, which lowers and strengthens the water permeability of the ground in this area.

In this case, the bottom opening of the device 3 may be closed, and a spouting hole may be formed in the wall surface of the outer tube 5 at the top of the device 3, and the liquid may be poured from there.

FIG. 4 shows that after pouring out the gelling material in FIG. 3, the device 3 is pulled up and a paracover gelling layer 8' is formed by the same operation as above, and in FIG. This indicates that a gel layer 8 is formed, and in this way, the ground around the drilled hole 2 is completely strengthened.

By the way, in the above case, the gelling material may be any material as long as it has the necessary physical properties, but for example, the main material A is an alkaline chemical solution such as water glass;
It is best to use a two-part chemical solution containing a curing agent B such as an organic acid or magnesium sulfate. It is shown in FIG.

Therefore, application of such a gelling material to the above-mentioned injection method will be explained with reference to an example of the injection apparatus shown in FIGS. 7 and subsequent figures.

7 and 8 show the state of the injection device 3 during the first step, 11 is the bottom wall of the passage 10, above which a partition 12 having through holes 18 is provided at a required interval, A valve chamber 13 is formed between both walls 11 and 12.

A cylindrical valve 14 is disposed in this valve chamber 13 so as to slide along both the inner and outer walls, and a mixing chamber 24 is placed above the valve 14.
is formed, and this valve 14 is connected to a spring 1 installed below the valve 14.
5, it is always urged upward.

In the valve chamber 13 portion, the walls of the inner and outer tubes 4 and 5 are provided with a plurality of through holes 16 and 17 which are closed by the valve 14 in the upper part in this state, and a plurality of through holes 19 which are not closed by the valve 14 in the lower part. 20 are drilled in each case.

An annular valve 21 that closes the through hole 19 in the inner tube 4 is held in this position by a shear pin or a spring (not shown), and an annular valve that supports the valve 21 when the valve 21 descends to open the through hole 19 is below it. A seat 22 is provided.

Although the first step is carried out by such a device as described in connection with FIG. 1, there is no need to add further explanation regarding this point, so the explanation will be omitted.

The second step following the first step performed as described above will be explained with reference to FIG. 910.

A ball valve 23 is dropped into the two passages 9, and the opening of the annular valve 21 is closed by the ball valve 23.

Here, when the long-term gelling main material A1+B1 containing chemical solutions A and B at the blending ratio B1/A1, which requires a long time for gelling as shown in FIG. 6, is supplied to the passage 9, the pressure causes the ball valve 2 The shear pin holding the engaged valve 21 is cut, or in the case of a spring, the valve 21 is seated on the valve seat 22 against its compression, thereby closing the bottom opening of the passage 9.

On the other hand, in the passage 10, a mixture ratio of B2/B2 as shown in FIG. A curing material consisting of liquid B or chemical liquid C, which is different from liquid B and has a similar effect, is supplied so as to become AI.

This hardening material B or C enters the mixing chamber 24 through the through hole 18, presses down the valve 14 against the pushing force of the spring 15, and presses down the valve 14 through the through hole 19.
is closed, and the through holes 16 and 17 are opened.

In this way, the main material and the hardening material are mixed in the mixing chamber 24,
Here, it becomes an instant-setting gelling material and is poured into the pores through the through hole 1γ, forming a packer 1 in the pores as shown in the second figure.

The eighth step following the second step performed as described above will be explained with reference to FIGS. 11 and 12.

If the supply of hardening material from the passage 10 is stopped here, the valve 1
4 is pushed up by the spring 15 to close the through hole 1617 and open the through hole 19.

As a result, the long-lasting gelling material A1-)-B1 is
9, through the valve chamber 13 and the through hole 20, is poured into the pore space below the packa γ, and is injected into the pore wall to form a gelled layer 8 as shown in the third figure. pull up

Tsuguko repeated the same process three times, and the results are shown in Figure 5.

This invention is as described above, and the conventional drilling pipe for excavating a hole while discharging excavation slag using polling water is made into a double pipe to provide a supply passage for the polling water after the collapse IJ process is completed. The bottom opening of the tube is closed, and the gelling material is supplied here for a long time, and the hardening material is supplied into the outer tube, and the art materials are mixed in the mixing chamber at the inner bottom of the outer tube to form an instant-setting gelling material. Since this is poured into a hole well above the bottom of the hole to form a hole, a hole whose upper end is tightly plugged by the hole is created between this hole and the bottom of the hole.

Thereafter, the bottom opening of the inner tube is opened and the gelling material is poured out toward the pore, and the gelling material is injected into the hole wall below the pad.
This prevents seepage, so that the infiltration into the hole wall can be carried out accurately and thoroughly to ensure strengthening of the ground and reduction of permeability, and the work can be carried out by drilling,
Bubble formation and chemical injection are all performed by a single injection device, so the work procedure is simple and the work is carried out efficiently, so construction costs are extremely low. After the completion of the construction method, the parts are recovered on the ground and used repeatedly, which has various effects such as reducing the cost of the equipment.

[Brief explanation of the drawing]

Figures 1 to 5 are schematic diagrams showing the order of the method of the present invention, Figure 6 is a graph showing the relationship between the mixing ratio of chemicals used in the method of the present invention and gelation time, and Figure 18. 910 is a longitudinal sectional view of the whole and essential parts of an example of the apparatus used in the construction method of the present invention in the first step shown in FIG. 1, and FIG. 910 is a similar longitudinal sectional view in the second step f shown in FIG. A top view, FIG. 1112 ν is a similar vertical cross-sectional view in the third step. 1...Ground, 2...Drilling, 3...
...Injection device, 4...Inner tube, 5...Outer tube, 6...Drilling blade, 17'9 Tsuγ"...Patsuka, 88 '8''...Gel layer, 9...9 Ri...Inner tube passage, 10...Outer tube passage, 11...
... Bottom wall, 12 ... Partition wall, 13 ...
Front chamber, 14... Cylindrical valve, 15... Spring, 16-20... Through hole, 21... Annular valve, 23... ...Ball valve, 24...Mixing chamber.

Claims (1)

[Claims] 1 Using a double pipe with a drilling blade at the tip, drilling water was supplied to the inner pipe, and the first step was to drill the hole without discharging drilling slag using this supplied water, and the bottom opening of the inner pipe was closed. Moreover, by supplying a gelling material for a long time in the same tube and a hardening material in the outer tube,
In a mixing chamber within the outer tube located considerably above the bottom of the hole, the above-mentioned art materials are mixed to form an instant-setting gelling material, and
a second step of pouring the gel out of the outer tube from the mixing chamber to form a pack at -TIJ* around the mixing chamber; A chemical injection method characterized by comprising a third step of injecting a chemical agent into the hole wall below the patch.