JP7050188B1 - Tunnel backfill material injection method and equipment, backfill material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a backfill material injection device capable of reliably and efficiently injecting a high-strength backfill material into a backfill portion. A backfill material injection device 10 mixes cement, water, or cement, water, and micelle agent with a mixer 16 that mixes aggregate, water, and micelle agent to create a gel-like aggregate. A mixer 24 for creating cement gel, an aggregate gel pump 12 for pumping a gel-like aggregate to the vicinity of the face of tunnel 4, a cement gel pump 21 for pumping cement gel to the vicinity of the face of tunnel 4, and the like. A mixer tank 40 that mixes a gel-like aggregate and cement gel to create a backfill material 7a, and a backfill injection pipe 8 that injects the mixed backfill material 7a into the backfill portion 7 of the tunnel 4. Be prepared. [Selection diagram] Fig. 1

Description

The present invention relates to a tunnel backfill material injection method and device for injecting a backfill material into a tunnel backfill portion (hereinafter, also referred to as a tail void) when constructing a tunnel, and a backfill material.

Generally, when constructing a tunnel, the backfill material is injected into the backfill portion formed between the lining body (segment) and the ground. There are one-component and two-component methods for injecting the backfill material. The one-component type includes, for example, a mixture of cement, bentonite, aggregate, and water, and an admixture may be added to these as appropriate. This one-component type is now mainly used in the backfill of mountain tunnels.

In addition, a backfill material is created at the tunnel starting base, and the backfill material is pumped through a pipe in the tunnel by a pressure feeding means such as a pump, and is filled in the backfill portion near the cutting edge in the tunnel.

Two-component type is mainly used for shield tunnel construction. For example, liquid A and liquid B are prepared at the tunnel starting base. The liquid A is, for example, a mixture of cement, aggregate and clay, bentonite and water, and the liquid B is a coagulant such as a water glass solution.

The liquid A and the liquid B are pumped from the tunnel starting base through different pipes, mixed near the rear end of the shield excavator, and injected and filled in the backfill portion. By mixing the coagulant of the liquid A with the coagulant of the liquid A, the gelation and coagulation of the backfill material of the liquid A is accelerated so that the backfill portion is placed so as not to be diluted with groundwater.

In recent years, in long-distance shield tunnel construction, the coagulant of liquid A and liquid B is pumped by separate pipes at the starting base or in the tunnel pit. Liquid A is a mixture (mortar) containing an aggregate such as sand or clay and a solidifying material such as cement.

At the same time as the shield excavator excavates, the liquid A and the liquid B are mixed immediately after the shield excavator and filled into the backfill portion from the rear of the shield cylinder by a press-fitting pump. In the vicinity of this backfilling portion, a coagulant as liquid B is added to liquid A and mixed, and this is filled in the backfilling portion so as to be coagulated (gelled) at an early stage.

Japanese Unexamined Patent Publication No. 2016-166447

However, if the excavation of the shield excavator is hindered and the excavation operation is stopped, the backfill material cannot be injected into the backfill portion. Therefore, the solidifying material such as the cement of the liquid A filled in the pipe in the tunnel pit is solidified. As a result, the mortar of the liquid A is removed from the pipe and cleaned in the tunnel. Alternatively, it is necessary to dismantle the pipe and transport it to the starting base on the ground to remove the solidified backfill material. Alternatively, the above-mentioned piping may be replaced, which increases the replacement work time and cost.

Until now, in shield tunnel construction, the fluidity of the backfill material has been emphasized in order to achieve good workability. In Japan, shield tunnel construction has been widely adopted in soft ground. Therefore, there is little need for a backfilling material with high strength.

Since the ground around the shield tunnel was often soft ground, cement, clay, and bentonite were the main aggregates for Liquid A.

In recent years, in shield tunnel construction, cases of passing through the hard ground of the Tertiary layer and rock mass are increasing.

Therefore, at present, there is a demand for an efficient, highly safe and easy-to-construct injection method for injecting mortar or the like as a high-strength backfilling material. By filling the tunnel area with a backfill material that corresponds to the strength of the surrounding ground, the ground and the lining body (segment) can be integrated, and a rational lining body using the spring of the ground can be designed. Therefore, the thickness of the lining body can be reduced. Alternatively, there is an advantage that the reinforcing bars inside the lining body can be reduced.

By the way, in the technique described in Patent Document 1, the mortar (liquid A) and the curing accelerator (water glass) are separately produced. The solution A contains sand and cement. In this technology, when the long-term excavation operation is stopped due to the mortar being pumped into the pipe, solidification occurs due to the hardening of the mortar in the pipe, which makes it impossible to continuously inject backfill and aggregate. It is also impossible to reuse the sand. Further, there is a problem that it takes a lot of time and cost to clean the inside of the solidified pipe as described above.

The present invention has been made in consideration of the above circumstances, and provides a tunnel backfilling material injection method and device capable of reliably and efficiently injecting a high-strength backfilling material into a backfilling portion, and a backfilling material. The purpose is to do.

In order to solve the above problems, the invention according to claim 1 of the present invention prepares a gel-like aggregate by mixing aggregate, water, and a thickener at the starting base of the tunnel or in the mine of the tunnel. A second mixing step of mixing cement, water, or cement, water, and a thickener to prepare a cement gel at the starting base of the tunnel or in the mine of the tunnel, and the first mixing step. The first pumping step of pumping the gel-like aggregate mixed by the mixing step 1 to the vicinity of the face of the tunnel through the first pipe, and the cement gel mixed by the second mixing step. , The second pumping step of pumping to the vicinity of the face of the tunnel through the second pipe, and the gel-like aggregate and the cement gel pumped to the vicinity of the face of the tunnel are mixed to prepare a backfilling material. It has a third mixing step and an injection step of injecting the backfill material mixed by the third mixing step into the backfill portion of the tunnel.

Further, in the invention according to claim 2, in addition to the configuration according to claim 1, a defoaming agent is added to the aggregate, the water, and the thickener in the first mixing step. Add to create the gel-like aggregate.

Further, in the invention according to claim 3 of the present invention, in addition to the configuration according to claim 1 or 2, a coagulant is mixed with the backfill material immediately before the injection of the backfill material into the backfill portion. inject.

Further, the invention according to claim 4 of the present invention is a first mixing method for producing a gel-like aggregate by mixing aggregate, water, and a thickener at a starting base of a tunnel or in a tunnel. By the means and a second mixing means for producing a cement gel by mixing cement, water, or cement, water and a thickener at the starting base of the tunnel or in the tunnel pit, and the first mixing means. The first pumping means for pumping the mixed gel-like aggregate through the first pipe to the vicinity of the face of the tunnel and the cement gel mixed by the second mixing means in the second pipe. A second pumping means for pumping to the vicinity of the face of the tunnel through the tunnel, and a gel-like aggregate body and a second pumping means installed near the face of the tunnel and pumped by the first pumping means. A third mixing means for mixing the cement gel to create a backfill material, and an injection means for injecting the backfill material mixed by the third mixing means into the backfill portion of the tunnel. To be equipped.

Further, the invention according to claim 5 of the present invention includes at least the cement, the aggregate, the water, and the thickener as the components of the backfilling material according to claim 1 or 4.

Further, in the invention according to claim 6, the component of the backfilling material according to claim 3 includes at least the cement, the aggregate, the water, the thickener, and the coagulant. ..

Further, in the invention according to claim 7 of the present invention, the backfill material according to claim 1 or 4 has a ratio of the water to the cement of 50% or less.

Further, in the invention according to claim 8 of the present invention, in the backfilling material according to claim 1 or 4, the ratio of the water to the cement is 50%, and the weight per 1 m ³ is the above. The amount of water was 440 kg, the cement was 880 kg, and the aggregate was 528 kg. The ratio of the water to the aggregate in the gel-like aggregate was 42 to 21%, and the ratio of the water to the cement in the cement gel was 42 to 21%. It is 38 to 25%, and the ratio of the water to the thickener is 1.50 to 3.0%.

〔式中、ＸはＲ１ａ又はＲ１ｂ-〔ＣＯＮＨ－ＣＨ_２ＣＨ_２ＣＨ_２〕ｎ－で表される基である。Ｒ１ａは、炭素数１４以上２２以下のアルキル基又は炭素数１４以上２２以下のアルケニル基である。ｎは１以上３以下の整数である。Ｒ^２およびＲ^３は、それぞれ独立に、炭素数１以上４以下のアルキル基又は－（Ｃ_２Ｈ_４Ｏ）ｐＨで表される基である。ｐは、平均付加モル数であり、Ｒ^２およびＲ^３の合計で０以上５以下の数である。〕。 Further, in the invention according to claim 9 of the present invention, the thickener according to any one of claims 1 to 8 is a micelle agent, and the micelle agent is the following general formula (1). A micellar agent containing two or more compounds represented by the above, wherein the two or more compounds differ in X in the general formula (1), and at least one of the two or more compounds. Is a backfilling material in which R1a or R1b of X in the general formula (1) is a compound having an alkenyl group and is further composed of a combination with an anionic compound.

[In the formula, X is a group represented by R1a or R1b- [CONH-CH ₂ CH ₂ CH ₂ ] n-. R1a is an alkyl group having 14 or more and 22 or less carbon atoms or an alkenyl group having 14 or more and 22 or less carbon atoms. n is an integer of 1 or more and 3 or less. R ² and R ³ are each independently an alkyl group having 1 or more carbon atoms and 4 or less carbon atoms or a group represented by − (C ₂ H ₄ O) pH. p is the average number of added moles, and is a ^total number of ^R2 and R3 of 0 or more and 5 or less. ].

Further, in the invention according to claim 10 of the present invention, the cement gel according to any one of claims 1 to 8 has a ratio of the cement to the cement dispersant of 0.2 to 0.7%. Is.

According to the inventions of claims 1 to 10 of the present invention, an aggregate, water, and a thickener are mixed to prepare a gel-like aggregate, and cement, water, or cement, water, and augmentation are prepared. The adhesive is mixed to make a cement gel, and these gel-like aggregates and cement gel are separately pumped to the vicinity of the face of the tunnel, and these gel-like aggregates and cement gel are mixed to make a backfill material. By injecting the backfilling portion into the backfilling portion, a high-strength backfilling material can be reliably and efficiently injected into the backfilling portion.

Further, according to the inventions of claims 1 to 10, since the gel-like aggregate does not contain cement, it does not solidify at all for a long period of time and is easy to handle. This facilitates cleaning of the inside of the pipe for pumping the gel-like aggregate, and can reuse the sand in the gel-like aggregate.

It is a system diagram which shows the structure of the backfill material injection apparatus of the tunnel which concerns on one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[One Embodiment]
FIG. 1 is a system diagram showing a configuration of a tunnel backfill material injection device according to an embodiment of the present invention.

As shown in FIG. 1, the shield excavator 1 mainly includes a skin plate 2, a cutter head 3, a propulsion jack (not shown), and a segment assembly device. The shield excavator 1 excavates the ground 5 in front of the shield excavator 1. On the other hand, behind the shield excavator 1, the segment 6 is assembled in a ring shape using the segment assembling device, and a backfill portion (tail void) formed between the assembled segment 6 and the excavation hole 5a of the ground 5 is formed. A tunnel construction is carried out in which the backfilling material 7a is injected into the backfilling material 7a from the discharge port 8a of the backfilling material injection pipe 8 to construct the tunnel 4.

<Structure explanation of backfill material injection device>
The backfill material injection device 10 pumps the aggregate gel manufacturing equipment 11 that mainly creates a gel-like aggregate and the gel-like aggregate manufactured by the aggregate gel manufacturing equipment 11 to the vicinity of the face of the tunnel pit 4a. The aggregate gel pumping pump 12 as the first pumping means, the cement gel manufacturing facility 20 for producing the cement gel, and the cement gel manufactured by the cement gel manufacturing facility 20 are pumped to the vicinity of the face of the tunnel pit 4a. A cement gel pump 21 as a second pumping means, a coagulant manufacturing facility 30 for producing a coagulant, and a coagulant for pumping the coagulant produced by the coagulant manufacturing facility 30 to the backfill material injection pipe 8. A third mixing means for mixing the pump 31 and the gel-like aggregate pumped by the aggregate gel pump 12 and the cement gel pumped by the cement gel pump 21 installed near the face of the tunnel pit 4a. The mixer tank 40 and the like are provided.

The aggregate gel manufacturing facility 11, the aggregate gel pumping pump 12, the cement gel manufacturing facility 20, the cement gel pumping pump 21, the coagulant manufacturing facility 30, and the coagulant pumping pump 31 are installed at the starting base 9 on the ground. There is.

The aggregate gel manufacturing equipment 11 includes an aggregate tank 13 for accommodating aggregate such as sand, a water tank 14 for accommodating water, a micelle agent tank 15 for accommodating a micelle agent, and measuring instruments 13a, 14a, 15a. It has a mixer 16 as a first mixing means. The aggregate mainly refers to sand, blast furnace slag, fly ash, microsand, limestone fine powder, stone powder, shirasu fine powder and the like, or a mixture thereof. Examples of the sand include river sand, sea sand, land sand, silica sand, crushed sand and the like. The measuring instruments 13a, 14a, and 15a measure the aggregate, water, and micelle, respectively. The mixer 16 creates a gel-like aggregate by stirring and mixing the aggregate, water, and micelle agent weighed by the measuring instruments 13a, 14a, and 15a.

In the present embodiment, the micelle agent and water are mixed with sand or the like at a constant ratio. In this embodiment, this is referred to as a gel-like aggregate. This gel-like aggregate body maintains an inseparable state suitable for pumping of the aggregate gel pump 12 for a long time, and has appropriate fluidity and viscosity. The aggregate gel pressure feeding pump 12 is connected to the mixer tank 40 via a gel-like aggregate body pipe 17. The gel-like aggregate pipe 17 extends from the start base 9 on the ground to the mixer tank 40 in the tunnel pit 4a via the start shaft 18 excavated in the ground 5. The mixer tank 40 includes a stirring device 40a.

The cement gel manufacturing facility 20 has a cement tank 22 for accommodating cement, a water tank 23 for accommodating water, measuring instruments 22a and 23a, and a mixer 24 as a second mixing means. The measuring instruments 22a and 23a measure cement and water, respectively. In the mixer 24, cement and water weighed by the measuring instruments 22a and 23a and, for example, a certain amount of a retarding agent are added and mixed to prepare a cement gel (cement milk). The cement gel pump 21 is connected to the mixer tank 40 via a cement gel pipe 25. Similar to the gel-like aggregate pipe 17, the cement gel pipe 25 also extends from the starting base 9 on the ground to the mixer tank 40 in the tunnel pit 4a via the starting shaft 18.

The coagulant manufacturing facility 30 has a coagulant tank 32 for accommodating the coagulant and a measuring instrument 32a including a flow meter for measuring the amount of the coagulant. As the coagulant, for example, a water glass solution having a predetermined concentration is used. The coagulant pressure feed pump 31 is connected to a mixing unit 41 having a stirring and mixing function via a coagulant pipe 33. The mixing portion 41 is installed near the face of the tunnel pit 4a. The mixing portion 41 is arranged in the backfill material injection pipe 8. The coagulant pipe 33 extends from the starting base 9 on the ground to the mixing portion 41 in the tunnel pit 4a via the starting shaft 18. The mixing unit 41 adds and mixes a coagulant to the backfilling material 7a supplied toward the backfilling material injection pipe 8.

The mixer tank 40 in the tunnel 4a is connected to the backfill material injection pipe 8 via the injection pipe 42. The backfill material injection pipe 8 is attached to the skin plate 2 and has a discharge port 8a at the tip thereof, which is opened rearward toward the backfill portion 7. An injection pump 43 is arranged in the injection pipe 42. The backfill material injection pipe 8, the discharge port 8a, the injection pipe 42, and the injection pump 43 constitute the injection means of the present embodiment.

<Explanation of the operation of the backfill material injection device>
Next, the operation of the backfill injection device 10 of the present embodiment will be described.

At the starting base 9 on the ground, the sand which is the aggregate of the aggregate tank 13, the water of the water tank 14, and the micelle agent of the micelle agent tank 15 are weighed by the measuring instruments 13a, 14a, and 15a, respectively, and transferred to the mixer 16. Will be done. In this mixer 16, sand, water, and a micelle agent are stirred and mixed to form a gel-like aggregate (first mixing step). As described above, this gel-like aggregate body maintains an inseparable state suitable for pumping the aggregate gel pump 12 for a long time, and has appropriate fluidity and viscosity.

Therefore, the gel-like aggregate can be easily pumped by the aggregate gel pump 12 similar to a concrete pump or the like. When the length of the tunnel 4 is very long as in the present embodiment, a relay pump can be used. When the aggregate gel pump 12 is driven, the gel-like aggregate is pumped and stored in the vicinity of the shield excavator 1, that is, the mixer tank 40 near the face, via the gel-like aggregate pipe 17. First pumping step). In this mixer tank 40, long-term fluidity and inseparability can be ensured by stirring with the stirring device 40a.

Further, at the starting base 9 on the ground, for example, a certain amount of retarder is added and mixed with the cement weighed from the cement tank 22 by the measuring instrument 22a and the water also weighed from the water tank 23 by the measuring instrument 23a. A cement gel is prepared (second mixing step). This cement gel is pumped by the cement gel pump 21 to the mixer tank 40 near the shield excavator 1 via the cement gel pipe 25 (second pumping step). In the third mixing step, by stirring with the stirring device 40a provided in the mixer tank 40, the gel-like aggregate is kneaded to produce a backfilling material. The backfill material 7a is pumped to the mixing unit 41 having a stirring and mixing function via the injection pipe 42 by driving the injection pump 43, and then from the discharge port 8a via the backfill material injection pipe 8. It is injected into the backfill portion 7 (injection step).

Here, a plurality of mixer tanks 40 may be installed, for example, in a large-diameter tunnel when a large amount of backfill material 7a is injected or when the excavation extension of the tunnel 4 is a long distance. In this case, a plurality of injection pumps 43 are similarly installed.

Further, at the starting base 9 on the ground, in the coagulant tank 32, for example, a water glass liquid having a predetermined concentration, which is a coagulant, is weighed by the measuring instrument 32a and used by the coagulant pump 31 to the mixing portion 41 near the shield excavator 1. By pumping, it is added and mixed with the backfilling material 7a prepared as described above. Here, it is desirable that the injection amount of the solution containing water glass as a coagulant is 2.5 to 4.5% of the backfill material 7a. In this embodiment, a water glass-based coagulant is used as the coagulant, but the present invention is not limited to this, and an aluminum salt-based or aluminum hydroxide-based coagulant may be used. Then, in the present embodiment, although not shown, the mixing portion 41 may be attached to the backfill injection hole of the assembled segment and directly filled in the backfill portion 7.

In the mixing section 41, a coagulant such as water glass liquid is added and mixed with the backfilling material, and the coagulant is discharged from the discharge port 8a of the backfilling injection pipe 8 to the tail void which is the backfilling section 7 and is filled in the backfilling section 7. .. The mixing portion 41 may be arranged in the backfill injection pipe 8.

Further, in the present embodiment, instead of the cement gel (gel-like cement), the gel-like aggregate and the cement gel are pumped to the vicinity of the face of the tunnel pit 4a by a separate system, and the gel-like aggregate is sent near the face. The body and cement gel may be mixed in a mixer tank 40, a line mixer, or the like to prepare a backfilling material 7a. The backfilling material 7a is filled in the backfilling portion 7 via the injection pipe 42 and the backfilling material injection pipe 8 by driving the injection pump 43 in the same manner as described above. The above-mentioned cement gel refers to a gel-like product obtained by mixing a thickener such as a micelle agent.

As the thickener, for example, methyl cellulose (MC) is used in addition to the micelle agent. As the thickener for cement concrete other than methylcellulose, for example, a biopolymer-based thickener made from an enzyme or a polyacrylamide-based thickener which is an acrylic synthetic product is used.

Furthermore, the cement gel is made by mixing cement, water, and a cement dispersant (Mighty (trade name: manufactured by Kao Corporation), etc.) at the starting base 9 on the ground, and using separate piping to shield the cement gel. It is pumped to the rear of the excavator 1. It is more preferable to add other additives such as dispersants and retarders to the cement gel depending on the pumping distance, pot life and the like. The amount of the dispersant used is preferably about 0.2 to 0.7% of that of cement.

Here, the production of sand gel and the production of cement gel are carried out not only in the tunnel pit 4a and the starting base 9 but also in the neighboring concrete depending on the conditions such as no sand storage place being provided at the land of the starting base 9 on the ground. It may be manufactured by diverting plant equipment. Since this concrete plant equipment is permanently installed and permanently installed by highly accurate management equipment and skilled management engineers, it is possible to manufacture cement gels and gel-like aggregates with ensured accuracy, and the starting base is from here. It is preferable to transport up to 9 using a concrete transport truck (concrete truck).

<Explanation of each material used in this embodiment>
Next, each material used in this embodiment will be described.

The gel-like aggregate has fluidity, viscosity, and has the property of containing sand and the like and not easily separated, so that the gel-like aggregate can be easily pumped by the aggregate gel pump 12 for a long time. Maintained. The gel-like aggregate exhibits a yogurt, boiled, and grated grated yam-like state. Since the gel-like aggregate does not contain a hardening material such as cement, the gel-like aggregate body pipe 17 does not cause a consolidation phenomenon.

In the gel-like aggregate, the sand used as the aggregate contains a small amount of soil particles below the silt (sinking), but the above-mentioned micelle agent is affected by the soil particles below the silt. Since there is almost no deterioration in performance due to the above, it is possible to prepare a gel-like aggregate in a stable state by using a micelle agent.

〔式中、ＸはＲ１ａ又はＲ１ｂ-〔ＣＯＮＨ－ＣＨ_２ＣＨ_２ＣＨ_２〕ｎ－で表される基である。Ｒ１ａは、炭素数１４以上２２以下のアルキル基又は炭素数１４以上２２以下のアルケニル基である。ｎは１以上３以下の整数である。Ｒ^２およびＲ^３は、それぞれ独立に、炭素数１以上４以下のアルキル基又は－（Ｃ_２Ｈ_４Ｏ）ｐＨで表される基である。ｐは、平均付加モル数であり、Ｒ^２およびＲ^３の合計で０以上５以下の数である。〕
上記ミセル剤においては、砂等に少量含まれる粘土分が酸性あるいはアルカリ性であっても、これに影響されることがなく、長時間の砂ジェルの流動性の低下を抑えることができる。それに加えて、砂ジェルをセメント水と混合した後のアルカリ領域でも、流動性を保持することができ、シールド掘進中の裏込め材７ａの流動性を一定時間保持することもできる。 The micelle agent as a thickener used in the present embodiment is a micelle agent containing two or more kinds of compounds represented by the following general formula (1), and the two or more kinds of compounds are of the general formula (1). X in 1) is different, and at least one of the two or more compounds is a compound in which R1a or R1b of X in the general formula (1) is an alkenyl group, and further with an anionic compound. It consists of a combination.

[In the formula, X is a group represented by R1a or R1b- [CONH-CH ₂ CH ₂ CH ₂ ] n-. R1a is an alkyl group having 14 or more and 22 or less carbon atoms or an alkenyl group having 14 or more and 22 or less carbon atoms. n is an integer of 1 or more and 3 or less. R ² and R ³ are each independently an alkyl group having 1 or more carbon atoms and 4 or less carbon atoms or a group represented by − (C ₂ H ₄ O) pH. p is the average number of added moles, and is a ^total number of ^R2 and R3 of 0 or more and 5 or less. ]
In the above-mentioned micelle agent, even if the clay content contained in a small amount in sand or the like is acidic or alkaline, it is not affected by this, and it is possible to suppress a decrease in the fluidity of the sand gel for a long time. In addition, the fluidity can be maintained even in the alkaline region after the sand gel is mixed with the cement water, and the fluidity of the backfilling material 7a during shield excavation can be maintained for a certain period of time.

The micelle agent is effective in both weakly acidic and alkaline regions, and has a long-term retention ability at a low concentration. Further, since the micelle agent can impart fluidity without impairing the characteristics of the coagulant even when mixed with the coagulant liquid, it is possible to expand the application range of the micelle body. Blast furnace cement is a kind of mixed cement, and is manufactured by mixing a predetermined amount of blast furnace slag fine powder with Portland cement. This blast furnace slag fine powder is used as an aggregate in the present embodiment.

表１は、本実施形態における好適な裏込め材の配合例として３つのケースを示している。表２において、比較例とはミセル剤を使用しない事例である。表１において、Ｗ／Ｃは水とセメントとの比であり、Ｗ／Ｓは水と骨材との比である。 <Explanation of each embodiment>
Hereinafter, each specific embodiment will be described with reference to Tables 1 and 2.

Table 1 shows three cases as a suitable compounding example of the backfill material in the present embodiment. In Table 2, the comparative example is a case in which the micelle agent is not used. In Table 1, W / C is the ratio of water to cement, and W / S is the ratio of water to aggregate.

In the comparative example, the fine sand and water, which are clearly aggregates, are separated immediately and do not exhibit a gel-like property lacking fluidity and viscosity, and cannot be pumped by a pump or the like. rice field.

As shown in Table 1, the ratio of water to cement is 50%, and the weight per 1 m ³ is 440 kg of water, 880 kg of cement, and 528 kg of aggregate, and water and bone in the gel-like aggregate. The ratio to wood is 42 to 21%, the ratio of water to cement in cement gel is 38 to 25%, and the ratio of water to micelle agent is 1.50 to 3.0 as shown in Table 2. % Is desirable.

In Table 2, each of the formulations of Examples 1 to 4 uses the formulation case of Table 1. Further, in Table 2, W ×% is mass% with respect to water, and C ×% is mass% with respect to cement. In each of Examples 1 to 4, a micelle agent is blended. In each of Example 2, the gel-like aggregate and the cement water are not separated and have sufficient fluidity and viscosity. Therefore, the gel-like aggregate and the cement gel pump 21 are used for the gel-like aggregate and the cement gel, respectively. It was possible to pump cement water.

In these examples, the micellar agent is added to the formulation of the sand gel, but it is also effective to add an antifoaming agent of 2 to 3% of the micellar agent in addition to the micellar agent. As such a defoaming agent, a silicone-based defoaming agent is preferable, and by adding the defoaming agent, there is an effect of defoaming bubbles contained in the sand gel and improving the compressive strength of the cured product.

The mighty is a dispersant and has the effect of maintaining the fluidity of the cement gel and delaying the curing. It is desirable that the ratio of the cement to the cement dispersant is 0.2 to 0.3% in this cement gel.

It is also effective to add a micelle agent or a retarding agent in addition to the cement dispersant in order to enhance the fluidity and non-separability of the cement gel and delay the curing.

In Examples 1 to 4 of Table 2, the 28-day compressive strength (σ28) is secured to be 24 N / mm ² or more, indicating that it can be applied as a backfill material in high-strength ground. Was done. The non-separable performance of the gel-like aggregate was confirmed for about 3 days, and it was confirmed that the gel-like aggregate can be sufficiently used even when the excavation is stopped for about 3 days due to a shield excavation trouble or the like. In addition, it was suggested that the gel-like aggregate can be used even after 4 days because the recovery results of fluidity and inseparability were obtained by stirring even after 4 days. For cement gel, a pot life of about 6 to 12 hours can be obtained.

Further, in the present embodiment, a gel-like aggregate is created at the starting base 9 on the ground, and the gel-like aggregate is used to reach the vicinity of the face behind the shield excavator 1 by using an aggregate gel pump 12 or the like. Since it is transported over a long distance by a pipe 17 or the like, it is necessary to have a state where the sand settling is small and has a large fluidity, and the pipe resistance is small. not.

Further, the present invention is not limited to the formulation examples shown here. The composition can be changed as appropriate depending on the tunnel construction conditions and the type of cement and aggregate used.

In this embodiment, an example in which the gel-like aggregate and the cement gel are prepared at the starting base 9 on the ground has been described, but the present invention is not limited to this, and the gel-like aggregate and the cement gel may be created at the starting shaft 18 or the tunnel inside 4a. ..

<Effect of this embodiment>
As described above, in the present embodiment, while the gel-like aggregate body in which the aggregate, water, and the micelle agent are mixed is prepared at the starting base 9 on the ground, the cement gel is prepared and the aggregate gel is pumped separately. Pump 12 and cement gel pump 21 are pumped to the mixer tank 40, mixed in this mixer tank 40 to create a backfilling material 7a, transported to the mixer tank 40 near the injector by the injection pump 43, and injected piping. By injecting into the backfill portion 7 from the discharge port 8a of the backfill injection pipe 8 via the backfill portion 42, it is possible to reliably and efficiently inject the high-strength backfill material 7a into the backfill portion 7.

Therefore, since the gel-like aggregate of the present embodiment does not contain cement, it does not solidify at all even in a long period of time, and is easy to handle. As a result, the inside of the gel-like aggregate pipe 17 for pumping the gel-like aggregate can be easily cleaned, and the sand or the like in the gel-like aggregate can be reused.

Further, in the present embodiment, since the stirring device 40a is provided in the mixer tank 40, it is possible to delay the solidification time. In this case, since Patent Document 1 does not have a stirring device in the tank, it is difficult to handle because it solidifies faster than that of the present embodiment. The solidified material cannot be reused as a backfill material.

Incidentally, since all aggregates such as sand settle and separate immediately when mixed with water, it is difficult to pump them with a pump.

<Other embodiments>
It should be noted that the embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention.

The backfilling material of the present embodiment is not only injected into the backfilling portion 7 from the backfilling injection pipe 8 provided in the shield excavator 1, but also injected from the backfilling injection hole provided in the segment 6. Of course, it is also good.

As the cement of the backfill material of this embodiment, cement such as Portland cement or blast furnace cement, or other cement can be used.

1 Shield excavator 2 Skin plate 3 Cutter head 4 Tunnel 4a Tunnel underground 5 Ground 6 Segment 7 Backfill (tail void)
7a Backfill material 8 Backfill material injection pipe (injection means)
8a Discharge port (injection means)
9 Start base 10 Backfill material injection device 11 Aggregate gel manufacturing equipment 12 Aggregate gel pump (first pumping means)
13 Aggregate tank 13a Measuring instrument 14 Water tank 14a Measuring instrument 15 Micelle agent tank 15a Measuring instrument 16 Mixer (first mixing means)
17 Gel-like aggregate piping (first piping)
18 Starting shaft 20 Cement gel manufacturing equipment 21 Cement gel pumping pump (second pumping means)
22 Cement tank 23 Water tank 24 Mixer (second mixing means)
25 Cement gel piping (second piping)
30 Coagulant manufacturing equipment 31 Coagulant pump 32 Coagulant tank 32a Measuring instrument 33 Coagulant piping 40 Mixer tank (third mixing means)
40a Stirrer 41 Mixing part 42 Injection piping (injection means)
43 Injection pump (injection means)

Claims (10)

A first mixing step of mixing aggregate, water, and a thickener to form a gel-like aggregate at the starting base of a tunnel or in the tunnel.
A second mixing step of mixing cement, water, or cement, water, and a thickener to form a cement gel at the starting base of the tunnel or in the tunnel.
The first pumping step of pumping the gel-like aggregate mixed by the first mixing step to the vicinity of the face of the tunnel through the first pipe, and the first pumping step.
A second pumping step of pumping the cement gel mixed by the second mixing step to the vicinity of the face of the tunnel through the second pipe, and a second pumping step.
A third mixing step of mixing the gel-like aggregate body pumped to the vicinity of the face of the tunnel and the cement gel to prepare a backfill material.
An injection step of injecting the backfill material mixed by the third mixing step into the backfill portion of the tunnel, and an injection step.
How to inject the backfill material of a tunnel with. The tunnel backfill material injection according to claim 1, wherein in the first mixing step, a defoaming agent is added to the aggregate, the water, and the thickener to prepare the gel-like aggregate. Method. The method for injecting a backfill material into a tunnel according to claim 1 or 2, wherein a coagulant is mixed in the backfill material and injected into the backfill portion immediately before the injection of the backfill material. A first mixing means for mixing aggregate, water, and a thickener to form a gel-like aggregate at the starting base of a tunnel or in the tunnel.
A second mixing means for producing a cement gel by mixing cement, water, or cement, water, and a thickener at the starting base of the tunnel or in the tunnel.
A first pumping means for pumping the gel-like aggregate mixed by the first mixing means to the vicinity of the face of the tunnel through the first pipe.
A second pumping means for pumping the cement gel mixed by the second mixing means to the vicinity of the face of the tunnel through the second pipe, and a second pumping means.
The gel-like aggregate installed near the face of the tunnel and pumped by the first pumping means and the cement gel pumped by the second pumping means are mixed to prepare a backfill material. 3 mixing means and
An injection means for injecting the backfill material mixed by the third mixing means into the backfill portion of the tunnel, and an injection means.
A tunnel backfill material injection device equipped with. The component of the backfilling material according to claim 1 or 4 is a backfilling material containing at least the cement, the aggregate, the water, and the thickener. The component of the backfilling material according to claim 3 is a backfilling material containing at least the cement, the aggregate, the water, the thickener, and the coagulant. The backfilling material according to claim 1 or 4, wherein the ratio of the water to the cement is 50% or less. The backfilling material according to claim 1 or 4 has a ratio of the water to the cement of 50%, and weighs 440 kg of the water, 880 kg of the cement, and 528 kg of the aggregate per 1 m ³ . The ratio of the water to the aggregate in the gel-like aggregate is 42 to 21%, the ratio of the water to the cement in the cement gel is 38 to 25%, and the water to the thickener . Backfilling material with a ratio of 1.50 to 3.0%. The thickener according to any one of claims 1 to 8 is a micelle agent, and the micelle agent is a micelle agent containing two or more compounds represented by the following general formula (1). The two or more compounds differ in X in the general formula (1), and at least one of the two or more compounds has R1a or R1b of X in the general formula (1). A backfilling material that is an alkenyl-based compound and is further composed of a combination with an anionic compound.

[In the formula, X is a group represented by R1a or R1b- [CONH-CH ₂ CH ₂ CH ₂ ] n-. R1a is an alkyl group having 14 or more and 22 or less carbon atoms or an alkenyl group having 14 or more and 22 or less carbon atoms. n is an integer of 1 or more and 3 or less. R ² and R ³ are each independently an alkyl group having 1 or more carbon atoms and 4 or less carbon atoms or a group represented by − (C ₂ H ₄ O) pH. p is the average number of added moles, and is a ^total number of ^R2 and R3 of 0 or more and 5 or less. ] The cement gel according to any one of claims 1 to 8 is a backfilling material in which the ratio of the cement to the cement dispersant is 0.2 to 0.7%.

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