JPS6183800A - Treatment of air bubble mixed muck - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Technical Field) The present invention aims to reduce the excavation resistance of the face ground against a rotary cutter in shield type tunnel excavation, or to provide fluidity and water-tightness against pickpockets in front of the bulkhead of the shield body. The present invention relates to a method for treating sludge containing air bubbles by injecting or extinguishing 1') air bubbles treated with a foaming agent or a foaming agent and a thickener in JtIm or sludge.

(Prior art) In foaming treatment, there are two cases: using an aqueous solution of a foaming agent;
An aqueous solution of a mixture of a foaming agent and a thickener may be used. In either case, in order to completely eliminate air bubbles from the shear containing air bubbles, it is necessary to wait for time to elapse or to take measures to promote defoaming. Compared to the case where only a foaming agent is used, when a foaming agent and a thickener are used together, highly stable air bubbles, so-called strong air bubbles, are generated, which further reduces the excavation resistance against the rotary cap of the face ground. It is possible to further improve shear fluidity and water-stopping properties in the pressurized area in front of the bulkhead of the shield body.
Defoaming in this case requires more time than in the former case. In any case, it is therefore advantageous to add an antifoaming agent to the aerated shear prior to or after its discharge from the pressurized area of the shield body into the atmospheric pressure area behind it, in order to promote antifoaming. It is.

By the way, bubbles have stability depending on the viscosity of the foaming agent aqueous solution, but by using only an antifoaming agent, it is not possible to sufficiently reduce the viscosity of the foaming agent aqueous solution, which determines the stability. , it was not possible to obtain complete defoaming or rapid defoaming.

(Objective) Therefore, one object of the present invention is to completely eliminate air bubbles mixed into shear by foaming treatment or air bubble mixing treatment.

(Construction and Effects) The present invention basically focuses on the distance between the shield body! ! ! By injecting or adding air bubbles obtained by foaming the ground or shear with a foaming agent at the front, the shear mixed with air bubbles is defoamed using a viscosity reducing agent and an antifoaming agent at the rear of the partition wall. By applying this, the viscosity-reducing agent lowers the viscosity of the foaming agent that forms the bubbles, leaving the bubbles in an unstable state. Under this condition, the foaming agent acts to quickly and completely form the bubbles. It is characterized by erasing.

In addition, 1 Raikou IjJ injects or applies air bubbles obtained by foaming a foaming agent and a thickener to the ground or shear in front of the bulkhead of the shield body, so that the bulkhead By performing defoaming treatment using a viscosity reducing agent and an antifoaming agent at the rear, the viscosity reducing agent reduces the viscosity of the foaming agent and thickening agent that form the bubbles, leaving the bubbles in an unstable state. , due to the action of the antifoaming agent under this condition,
It is characterized by eliminating air bubbles quickly and completely.

(Embodiments) The features of the present invention will become clearer from the following description of the illustrated embodiments.

In the present invention, there are two types of air bubbles that are mixed into the pickpocket to be treated. That is, bubbles are formed by an aqueous solution of a foaming agent, and bubbles are formed by an aqueous solution of a foaming agent and a thickener. The thickener has the property of further improving the stability of bubbles, and therefore,
The latter bubbles are less likely to break or crack than the former bubbles.

In the following explanation, we will discuss the latter case, that is, the case where the air bubbles mixed into the shear are formed using a foaming agent and a thickener. When obtaining air bubbles, equipment for foaming agents and thickeners, such as the pipes 28, 30, openings 26, 32, etc. described below, are also provided for the supply of air bubbles.

;fs 1 Figure 2 f Shielded tunnel uAal
ltffil.

is equipped with a jack 16 at the rear of the shield body 12 for propelling the shield body 12 by applying a reaction force to the segments 14, and a jack 16 for supporting a rotary cutter head 18 at the front and for applying forward force inside the shield body. A partition wall 24 is provided that divides the pressure region 20 into a rear atmospheric pressure region 22.

The cutter head 18 is equipped with a pipe 28 for supplying bubbles obtained by a foaming process in which a mixed aqueous solution of a foaming agent and a thickener is mixed with high-pressure air. The tube 28 extends to the cutter face via the rotation axis of the cutter 12,
a plurality of openings 2 directed from the cutter face to the blades;
It has 6. A plurality of pipes 30 for supplying air bubbles are also connected to the bulkhead 24, and the ends of the pipes 28 and 30 are connected to the face ground and in front of the bulkhead, respectively, to provide stability. This is due to the openings 026 and 32 for providing rich air bubbles or for supplying stable air bubbles to the shear. Furthermore, the partition wall 24 is agitated with a rotary cutter using a pickle and bubbles.

A plurality of 7 digitators 34 are provided to further enhance mixing.

Examples of foaming agents include Hozolith No. 505 (trade name) manufactured by Hozolith Bussan C Co., Ltd.

Furthermore, examples of the thickener include water-soluble polymeric materials. These water-soluble polymeric materials include plant-based natural products such as gum arabic, gum tragacanth, alginate, cornstarch, etc., animal-based natural products such as gelatin and casein, and processed and modified starch-based soluble starches, cationic starches, etc. and C belonging to cellulose
Semi-natural products such as MC (carboxymethyl cellulose), MC (methyl cellulose), IIIEG (hydroquinenol cellulose) τ, and vinyl-based PVA (polyvinyl alcohol) and PVP (polyvinylpyrrolidone)
etc., and synthetic products such as PE0 (polyethylene oxide) and polyphosphates.

1j mentioned above! According to Shinso, the excavation resistance of the cutter is reduced by the presence of air bubbles supplied from the cutter face between the cutter face and the face ground, and the air bubbles contained in the excavated earth and sand. The air bubbles or the air bubbles supplied to the excavated soil on the partition wall fluidize the pickpocket. In addition, this pickpocket has a sludge-like shape and is highly liquid-tight and air-tight, so it has the property of being advantageous in sliding out to the atmospheric pressure region 22 without causing a pressure drop in the pressurized region 20. have

According to the illustrated embodiment of the unreleased I11, a screw conveyor 36 installed in the atmospheric pressure region 22 is attached to the bulkhead 24 so that the inside communicates with the pressurized region 20. This screw conveyor 36 constitutes an intermediate discharge area for discharging the pickpockets from the pressurized area 20 at a distance M + iij force into the atmospheric pressure area 22 behind, and the screw conveyor 36 has its casing 38 and shaft 40 A device 42 for supplying an antifoam agent and a viscosity-reducing agent is connected to the inside via the .

The supply device 42 includes a source 42a of a mixture of antifoam and viscosity reducing agent and tubes 42b, 42c connected thereto. Openings 38a and 40a are provided in the casing 38 and shaft 40, respectively, for adding antifoam and viscosity reducing agent to the pickpocket at the minute position.

The screw conveyor 36 is provided with an opening/closing section s44 at the end opposite to the partition wall 24, and a belt conveyor 46 for sliding out is installed below the opening/closing section.

Face excavation inside screw conveyor 36, shield body 1
2 and the accompanying rise in pressure in the pressurized area 20, the bubble-mixed slurry is sent through the casing 38 and travels approximately 5 minutes, and then passes through the tubes 42b, 4. Upon addition of the antifoaming agent and viscosity reducing agent supplied through step 2c, the shear, antifoaming agent and viscosity reducing agent mix under the action of feeding and stirring generated by the rotation of the screw shaft, resulting in , defoaming, and
The foaming agent and water-soluble polymeric material used in foaming are reduced in viscosity to approximately the same level as water, returning to the same natural soil state as in the face ground.

In the case of foams obtained using foaming agents, the viscosity of the foaming agent is reduced by the action of the viscosity reducing agent, and as in the case of said foaming agents and water-soluble polymeric materials, the pickpocket is naturally It returns to the state of sand and earth.

Due to its fluidity, there is a risk that the air-bubbled shear will be rapidly discharged from the screw conveyor 36, but +iη
By defoaming as described above, compaction occurs and rapid discharge is prevented.

The antifoaming agent and the viscosity reducing agent may be added as a premixed mixture from the supply source 42a, or each may be added separately at the same time or sequentially. Examples of antifoaming agents include ethyl alcohol, Pronal 2400 (trade name) manufactured by Toho Chemical Industry Co., Ltd. Surfactants such as can be used. When the water-soluble polymeric material used as a thickener is a natural or semi-natural product, the viscosity-lowering agent may include starch hydrolase, protein hydrolase (amylase, protease, etc.), cellulose hydrolase (cellulase, etc.) ), # (hydrochloric acid, sulfuric acid, etc.), salts (chloride, sulfate,
carbonate, etc.), polyvalent metal ions (iron, chromium, nickel, etc.), etc. are preferred.Enzymes exhibit high activity in acidic environments and increase in reaction rate at high temperatures.
When using the enzyme, it is desirable to add an acid to the shear or heat the shear. In addition, when the water-soluble polymer material is a synthetic material, as a viscosity reducing agent, acids (hydrochloric acid, sulfuric acid, etc.), salts, etc. (chloride, sulfate, carbonate, etc.), polyvalent metal ions (iron, chromium, nickel), oxidizing agents (chlorine, hydrogen peroxide, permanganate, persulfate, etc.)
Delicious.

The shear that has been defoamed by being mixed with an antifoaming agent and a viscosity reducing agent in the screw conveyor 36, which is the discharge area, is
44 is gradually consolidated while moving, and when the entire inside of the screw conduit 736 is filled with bubble-mixed shear, the same water-tightness can be maintained. Therefore, even if the opening/closing part 44 is opened and the pickpocket which has returned to the bubble-free state 1s is discharged onto the belt conveyor 46 in the atmospheric pressure area 22, no pressure drop is caused in the pressurized area 20, and the face is stabilized. A predetermined pressure required for this can be maintained.

In the example shown in FIG. 2, the discharge area communicating with the pressurizing area 20 is shaped like a rotating drum! This scraping device, shown as an example constructed by J.A.A37, has a structure similar to that disclosed in Japanese Patent Publication No. 53-36257, and has a drum connected to the partition wall 24 and located inside the casing 38 and driven and rotated. 3
9, the drum is provided with a partition plate 41 that crosses the inside eccentrically, and a q opening 43 for receiving and discharging the pickpockets in the drum 39, and
8 is provided with an opening/closing part 44.

The pressure area 2 is compressed by clockwise angular rotation of the drum 39.
The shear that is received inside the drum 39 through the opening 43 is transferred to the opening 43 by rotation of the drum 39.
An antifoaming agent and a viscosity reducing agent supplied from the pipe 45 of the supply wave f142 are added to. By further angular rotation of the drum 39, the position shown in FIG. flffi2 is reached, that is, the position where the opening 43 is aligned with the opening/closing part 44, and the pickpocket, antifoaming agent, and viscosity reducing agent are stirred and mixed, and the air bubbles in the pickpocket are eliminated. be done. Thereafter, when the opening/closing part 44 is opened while the drum 39 is stopped at the illustrated position, the bubble-free waste is discharged from the drum 39 through the opening/closing part 44 of the casing 38 onto the belt conveyor 46, and continues to be large. Atmospheric pressure area 22
is carried out to the rear.

:fS3~6 rf4ha, Ki8i f! j'e)J
After the rl pressure M 20 is discharged into the atmospheric pressure region 22 with air bubbles mixed in it while preventing the pressure from decreasing, defoaming treatment is carried out using In foam cutting 8 and viscous low-tooth cutting inside the shield body 12 or in the tunnel. Alternatively, by utilizing the fluidity of the bubble-containing shear that exhibits a sludge-like shape, it is pumped directly from the pressurized area 20 to equipment installed on the ground, where it is discharged into the atmospheric pressure area 22 for defoaming treatment. Give an example.

First, the device δ shown in FIG. 3 has a discharge pipe 50 that is attached to the partition wall 24 and communicates with the pressurized area 20, and at the end thereof, discharges shear while maintaining a predetermined pressure in the pressurized area 20. A discharge mechanism 52 and a discharge port 54 are provided. A slider 56 is arranged below the discharge port 54, and the shield main body 12
The bubble-containing shear received in the discharge pipe 50 as a result of the propulsion is discharged out of the pipe in a bubbled state by the operation of the discharge mechanism 52, and is carried out of the shield body 12 by the waste retro 56. Thereafter, it is stirred and mixed with an antifoaming agent and a viscosity reducing agent in a sump installed in the tunnel or above ground. Of course, as shown in FIG. 4, an antifoaming agent and a viscosity reducing agent are added to the discharge port 54 under the discharge port 54, and the supply is carried out in order to stir and mix them. A sump 55 to which the C holder 42 is connected may be provided.

Next, FIGS. 5 and 6 show an example in which the discharge pipe 501 for the air bubbles mixed with shear shown in FIG.

A pump 60 for shear pressure feeding is installed in the pipe 50, and the pipe 50
A rotary valve 62 is provided near the end of the
The bubble-entrained shear is discharged into the shear reservoir 55 without a drop in the pressure inside the tube and thus in the pressurized area 20. Zuridame 55
Then, the antifoaming agent and the viscosity reducing agent sent from the feeder 42 are added to the slurry, and by stirring and mixing them, the slurry is brought to a bubble-free state, and is then transferred to the hopper 64, where it is transported by a normal vehicle such as a dump truck. The earth and sand are transported to the earth dumping site by Mll1 means.

Moreover, the equipment shown in FIG. 6 can be applied to the examples shown in FIG. S1 and FIG. 2, and thereby, defoaming treatment can be performed in the atmospheric pressure region. That is, instead of the belt conveyor 46 which is the shear conveyance means, the discharge pipe 50 is broken into the opening/closing part 44 of the screw conveyor 36 (FIG. 1) or the opening 12'1 part 44 (!fi21Δ) of the sliding device fi37. be able to. In this case, the antifoam and viscosity reducing agent supply device 42 shown in FIGS. 1 and 2 is not required.

According to Kibatsu 1, if the bubbles mixed in the pickpocket are formed by an aqueous foaming agent solution that does not contain a thickener, the action of the viscosity reducing agent will cause the foaming agent aqueous solution that forms the bubbles to The viscosity is reduced and eliminated quickly and completely by the action of the antifoaming agent.

In addition, when the bubbles are formed by an aqueous solution of a foaming agent containing a thickener, the action of the viscosity reducing agent added together with the antifoaming agent covers the bubbles in the slurry and increases the stability of the bubbles. The viscosity of the thickening agent, such as a water-soluble polymeric material, is significantly reduced, which places the bubbles under unstable conditions.
Due to the action of the antifoaming agent, the air bubbles are quickly and completely eliminated in this case as well.

Therefore, the viscosity of the foaming agent used for foaming or the viscosity of the foaming agent and the thickener contained in the foam-defoaming slurry is also extremely low. It has the properties of ordinary excavated soil, and there are no special regulations regarding its handling or soil disposal sites.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical sectional view showing an example of a shield type tunnel basement device used for carrying out the present invention. Figures 2, 3, 4, and 5 are longitudinal sectional views showing modifications of the device shown in Figure 1, and Figure 6 is a schematic diagram showing an example in which defoaming equipment is installed above ground. be. 10: Shield type tunnel excavation device. I2: Shield body, 18: Cutter head, 2θ
Pressurized area, 22 atmospheric pressure area, 24 bulkhead. Agent Patent Attorney Matsui Kan Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 P Amendment Date: November 1, 1982

Claims (5)

[Claims] (1) By injecting or applying air bubbles obtained by foaming the ground or shear with a foaming agent in front of the bulkhead of the shield body, a viscosity reducing agent and an antifoaming agent are added to the shear mixed with air bubbles at the rear of the bulkhead. 1. A method for treating shear mixed with air bubbles in shield type tunnel excavation, characterized by performing defoaming treatment using. (2) By injecting or applying air bubbles obtained by foaming a foaming agent to the ground or shear in front of the bulkhead of the shield body, the pressurized area behind the bulkhead and in front of the bulkhead is mixed with air bubbles. A viscosity reducing agent and an antifoaming agent are used to perform defoaming treatment in the discharge area communicating with the diaphragm, and then the defoamed shear is transferred to the pressurized area in front of the diaphragm while maintaining a predetermined pressure at the atmospheric pressure behind the diaphragm. 1. A method for disposing of air bubbles mixed in shear in shield type tunnel excavation, the method comprising discharging shear outside the discharge area in a shield type tunnel excavation. (3) By injecting or applying air bubbles obtained by foaming a foaming agent and a thickener to the ground or shear in front of the partition wall of the shield body, a viscosity reducing agent is added to the shear mixed with air bubbles at the rear of the partition wall. 1. A method for treating shear mixed with air bubbles in shield type tunnel excavation, characterized by carrying out defoaming treatment using an antifoaming agent and an antifoaming agent. (4) The defoaming treatment is performed in a discharge area located behind the partition wall and communicating with the pressurized area in front of the partition wall,
The method according to claim (3). (5) The method according to claim (3), characterized in that the defoaming treatment is performed in an atmospheric pressure region behind the partition wall.