JP2009249919A - Method for filling gap in tunnel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for filling a gap in tunnel over long distance by using air mortar efficiently. <P>SOLUTION: This method for filling the gap in tunnel by using air mortar comprises a mortar force-feeding step for force-feeding mortar into the tunnel by producing the mortar 14 outside the tunnel, a step for generating air bubbles in the tunnel, an air mortar producing step for mixing the air bubbles generated in the tunnel with the mortar 14 force-fed into the tunnel to produce the air mortar in the tunnel, and a step for filling the gap in the tunnel by using the air mortar. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for filling a gap in a tunnel.

  Conventionally, regarding the method of filling and consolidating the target site using air mortar, “Manufacturing air mortar with rock powder MP grout with calcium carbonate as the main component and reducing the amount of cement and MP grout as small as possible. In order to maintain the standard strength and maintain a stable property without causing volume reduction even in long-distance pumping of 1000 m or more, it is possible to fill and consolidate a predetermined portion. As a technology for the purpose of ‘Mixing and manufacturing MP grout air mortar by mixing the foam with AP foam and water and compressed air into a slurry with cement and MP grout and water, A method of “filling and consolidating a predetermined portion” has been proposed (Patent Document 1).

  In addition, regarding the filling material, “high fluidity can be maintained for a long time, the transportable distance can be extended by about twice, high filling property can be secured, and sufficient working time can be secured. Provide filling material. As a technology for the purpose of, "fluidity can be secured by adding polycarboxylate and calcium lignin sulfonate to the filling material mainly composed of cement and bentonite, and sufficient By using a retarding dispersant (calcium lignin sulfonate as a retarding agent) to secure working time, sufficient working time can be secured, and furthermore, by adding metallic aluminum and calcium hydroxide Filling material that is configured to generate hydrogen gas by the reaction of the above to foam and swell. Is proposed (Patent Document 2).

  In addition, regarding the gap filling method between the outer pipe and the inner pipe, “the filling material mainly composed of cement is injected into the gap between the outer pipe and the inner pipe over two or more construction cycles, and the filling material is cured. In the construction method, the piping required for the injection work is minimized without washing the piping, the waste of the filling material abandoned in the piping is eliminated, and the installation and connection work in the gap of the piping is reduced. As a technique for the purpose, “the length of the outer tube 1 and the length of the inner tube 2 are longer than the construction distances A, B, C for one cycle. The operation of inserting the pipe 4 for injecting the filling material into the gap 3 and injecting the filling material from the same pipe 4 into the gap is performed over two cycles or more without cleaning and replacing the pipe. When the filling of the filling material is finished at the end of each construction cycle, the filling material containing the setting retarder is filled into the pipe. Is proposed (Patent Document 3).

Japanese Patent Laid-Open No. 7-3771 (Summary) JP 2007-169974 A (summary) JP 2000-274187 A (summary)

In tunnel construction using the shield construction method, a tunnel is constructed by propelling the shield excavator, and the shield segment is assembled at the rear of the shield excavator for primary lining.
After the primary lining is completed, the technique described in the above-mentioned Patent Document 3 inserts a filling pipe into the gap between the inner pipe and the shield segment, injects and cures the filling material, and forms a secondary lining. This is related to the filling method.
For example, when a reinforced plastic composite pipe slightly smaller than the segment inner diameter is used as an inner pipe for carrying, joining, and fixing into the shield segment, a pipe that accommodates a lifeline such as a gas pipe or a water pipe that is considerably smaller than the segment diameter is used. In the case of a pipe, the technique described in Patent Document 3 is applied.

Air mortar has been used for the purpose of filling and solidifying and protecting the inner and outer pipe cavities with a filling material mainly composed of cement.
The reason why the air mortar is used is that, as described in Patent Document 2, the volume can be secured economically, the unit volume weight is lowered, and the like.

As described in Patent Document 2, the air mortar is one that adds a foaming agent at the time of kneading and pumps it in a state of bubbles, and requires high viscosity because it is necessary to stabilize the bubbles being transported.
For this reason, only a transport distance of 1000 to 1500 m can be secured, and there is a problem that a relay facility must be installed in order to perform long distance transport.

In the said patent document 2, in order to cope with these problems, metal aluminum powder is used as a foaming agent of air mortar or bentonite filling air mortar. Add metal aluminum powder, polymer dispersion and retarder to mortar and pump in mortar state.
After filling and filling the mortar that has been pumped, hydrogen reacts with calcium hydroxide in the shield to generate hydrogen gas and foam.
When the mortar is pumped, bubbles are not included in the mortar, so that high fluidity is maintained for a long time and the transportable distance is extended.

However, air mortar using a normal foaming agent has an air content of 30 to 70% with respect to the total volume, but foam mortar made of aluminum powder has a low bubble content of several percent or less and is economical. In particular, it is used for suppressing the amount of breathing after filling, rather than securing the volume or reducing the unit volume weight.
Therefore, the technique described in Patent Document 2 has a problem that sufficient volume cannot be secured and unit volume weight cannot be suppressed.

On the other hand, shields dedicated to pipe laying and mountain tunnels have become longer distances (for example, 10 km or more) in recent years, and in order to transport air mortar into the tunnel, it is necessary to install a multistage relay facility.
Therefore, there is a problem from the viewpoint of the quality deterioration of air mortar due to passing through a large number of relay facilities and the cost related to transportation.

  The present invention has been made to solve the above-described problems, and provides a gap filling method in a tunnel capable of efficiently filling a gap in a long distance tunnel using an air mortar. With the goal.

  A gap filling method in a tunnel according to the present invention is a method of filling a gap in a tunnel using air mortar, and a mortar pumping step of manufacturing mortar outside the tunnel and pumping it into the tunnel; Generating air bubbles in the tunnel; mixing air bubbles generated in the tunnel into mortar pumped into the tunnel to produce air mortar in the tunnel; and the air Filling the gap with mortar.

  According to the gap filling method in the tunnel according to the present invention, the mortar is manufactured outside the tunnel and is pumped into the tunnel, and the air mortar is manufactured in the tunnel and the filling is performed. There is no need for transportation, which is advantageous in terms of air mortar quality and transportation costs.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a state in which a gap filling method in a tunnel according to Embodiment 1 of the present invention is performed. Here, in the tunnel construction using the shield method, a case where the gap filling method in the tunnel according to the first embodiment is performed is taken as an example. It is assumed that the shield has a small diameter and does not have enough space to install large equipment in the shield.
The upper diagram of FIG. 1 shows the arrangement and connection relationship of each equipment installed in the ground equipment, and the lower diagram shows each equipment installed in the shield. Hereinafter, each equipment shown in FIG. 1 will be described.

The mortar mixer 10 produces mortar 14 by automatically measuring and mixing blast furnace cement 11, fine aggregate 12, and kneaded water 13.
The pressure feed pump 20 pressure-feeds the mortar 14 manufactured by the mortar mixer 10 to the mixing device 100 in the tunnel via the pressure feed pipe 30. The length of the pressure feeding pipe 30 is determined according to the distance between the mortar mixer 10 and the mixing apparatus 100 (for example, several km).
Since the mortar is incompressible unlike the air mortar, a piston pump or a mono pump is suitable for the pump.
Note that a flow rate adjusting valve may be provided at the terminal of the pressure feeding pipe 30 to adjust the amount of mortar flowing into the mixing device 100.

Dilution liquid 43 for generating bubbles is manufactured by mixing foaming agent 41 and dilution water 42 in the ground facility. The dilution factor is set to 20 to 100 times depending on the type of foaming agent.
The pressure-feed pump 50 pressure-feeds the diluent 43 manufactured by the ground facility to the foam cylinder 90 in the tunnel via the pressure-feed pipe 70.
For the size of the pressure feeding pipe 70, a small diameter pipe such as a 1 inch pipe is used because the amount of the diluent 43 fed is small. In addition, the length of the pressure feeding pipe 70 is determined according to the distance between the manufacturing location of the diluent 43 and the foamed cylinder 90 (for example, several km).

The compressor 60 is a compressor that is connected to the foam cylinder 90 by a pressure-feed air hose 80 and supplies compressed air to the foam cylinder 90. The length of the pressure air hose 80 is determined according to the distance between the compressor 60 and the foamed cylinder 90 (for example, several km).
The foaming cylinder 90 foams the diluent 43 using compressed air supplied from the compressor 60 and supplies the generated bubbles to the mixing device 100.
The mixing apparatus 100 manufactures an air mortar by mixing the mortar 14 supplied from the pressure feeding tube 30 and the bubbles supplied from the foaming cylinder 90.
For example, the illustrated mixing apparatus 100 is directly connected to the pressure feeding pipe 30 in the vicinity of the end point of the pressure feeding pipe 30, and the size is equal to or larger than the diameter of the mortar pressure feeding pipe 30, and the mortar and bubbles are merged to use the flow of the mortar. The mixing hose 110 is attached to the end point of the mixing apparatus 100 to fill the air mortar at a predetermined position.

  The mortar mixer 10, the pressure pumps 20 and 50, and the compressor 60 are installed in the ground facility. The foam cylinder 90 and the mixing apparatus 100 are installed near the filling position in the shield.

The “manufacturing means” in the present invention corresponds to the foamed cylinder 90 and the mixing apparatus 100. The configuration of the manufacturing means is not limited to this, and any configuration can be used as long as it can manufacture air mortar.
However, when the space in the shield is narrow, only relatively small devices such as the foam cylinder 90 and the mixing device 100 are separated and installed in the shield, and the remaining necessary components are outside the shield. It is preferable to install.

In the above, the role and connection relationship of each equipment shown in FIG. 1 were demonstrated.
Next, a procedure for filling the gap in the tunnel with the configuration of each equipment shown in FIG. 1 will be described in steps (1) to (6).

(1) The worker on the ground manufactures the mortar 14 using the mortar mixer 10 and pumps it to the mixing device 100 via the pumping pump 20 to the pumping tube 30. The viscosity of the mortar 14 is appropriately determined according to the distance that requires pressure feeding and the required specifications.
(2) When the worker on the ground manufactures the mortar 14, an admixture is added as necessary to add fluidity and cure retardance to the manufactured mortar 14.

(3) An operator on the ground mixes the foaming agent 41 and the diluting water 42 to produce the diluting solution 43, and pumps it to the foaming cylinder 90 via the pumping pump 50 to the pumping tube 70. Further, if necessary, a flow rate adjusting valve is provided between the pressure pump 50 and the foaming cylinder 90 to adjust the supply amount of the diluent to the foaming cylinder 90. Since the diluent 43 does not harden unlike mortar, it is stored in the pressure feeding tube 70 and the daily pressure feeding tube 70 is not cleaned after the work is completed. This is because it is not necessary to secure a space for placing a tank for storing the diluent 43 in the shield.

(4) An operator on the ground operates the compressor 60 to supply compressed air to the foaming cylinder 90 and causes the diluent 43 to foam within the shield. Bubbles generated from the foam cylinder 90 are supplied to the mixing apparatus 100. If necessary, an air regulator is provided between the compressor 60 and the foam cylinder 90 to adjust the pressure of the compressed air.

(5) The mixing apparatus 100 mixes the mortar 14 supplied from the pressure feeding tube 30 and the bubbles supplied from the foaming cylinder 90 to produce air mortar in the shield.
(6) An operator in the shield places an air mortar manufactured by the mixing apparatus 100 to fill the gap in the shield.

The procedure for filling the gap in the shield with the configuration of each equipment shown in FIG. 1 has been described above.
In addition, you may provide the relay pump for relaying the pumping of the mortar 14 and the dilution liquid 43 in a pumping path as needed.

The method for filling gaps in a tunnel according to the present invention can target any gap in the tunnel.
That is, the present invention can be applied to any gap in an environment that requires long-distance mortar transportation due to the fact that there is not enough space in the tunnel to install large equipment and the tunnel is long distance. The method for filling the gap in the tunnel according to the above works.

As described above, according to the first embodiment, the mortar 14 and the dilution liquid 43 are manufactured outside the shield and are pumped into the shield, and bubbles are generated using the foaming cylinder 90 inside the shield. The mortar 14 and air bubbles are mixed using an air to produce an air mortar.
Therefore, it is not necessary to pump air mortar into the shield, and it is only necessary to pump low-viscosity and incompressible mortar into the shield compared to air mortar, so it is longer than when air mortar is pumped. Can be transported.

  Moreover, according to this Embodiment 1, since air mortar is manufactured in a shield, compared with the case where air mortar is transported for a long distance, air defoams with transportation and the quality of air mortar falls. There is no concern, and filling can be performed using air mortar with stable quality.

Further, according to the first embodiment, since the mortar 14 is pumped and bubbles are mixed in the shield, the pumping amount of the mortar 14 itself can be small.
That is, since air mortar is, for example, about half of the volume of air bubbles, even when the same amount of air mortar is transported to the placement point, the air mortar itself is transported, and the mortar 14 is transported and the vicinity of the placement point. In the case of producing air mortar, the transport amount of mortar can be reduced to about half.
Therefore, if the air mortar is manufactured in the shield, the air mortar can be more efficiently delivered to the placement point, and a larger amount of placement work can be performed within the same time.

  Further, according to the first embodiment, since the compressor 60 is installed outside the shield and connected to the foamed cylinder 90, even when the space in the shield is narrow and there is no room to install the compressor 60, The air mortar can be manufactured without any hindrance and the filling operation can be carried out.

Embodiment 2. FIG.
In the first embodiment, the example in which the compressor 60 is installed outside the shield and connected to the foamed cylinder 90 has been described. However, when the compressor 60 can be sufficiently downsized, or when there is a space in the shield, The compressor 60 may be installed in the shield.
Even in this case, the same effect as in the first embodiment can be exhibited in that it is not necessary to pump the air mortar from the outside of the shield into the shield.

In the first and second embodiments, it has been described that the mortar 14 is manufactured with ground equipment and is pumped into the shield. The mortar 14 has a lower viscosity than the air mortar and is suitable for long-distance transportation. However, the transportable distance of the mortar 14 itself can be increased by devising the formulation when producing the mortar 14. .
Therefore, in the examples of the present invention, the results of demonstrating the optimum blending of the mortar 14 will be described.

  First, the following (1) to (6) were set as conditions necessary for air mortar used for filling the gap in the shield. Hereinafter, each condition and its reason will be described.

(1) Strength capable of re-digging: Compressive strength q = 5 kg / cm 2 or less When re-digging is required in the future, the uniaxial compressive strength was determined so as to facilitate excavation when removing the solid air mortar. In addition, since the purpose of placing the air mortar is to protect the piping, the air mortar itself does not require great strength. Therefore, the strength was determined as described above.

(2) Gas permeability capable of gas detection: Air permeability coefficient k = 1.0 × 10-1 cm / sec or more When gas leaks from the gas pipe after filling the gap between the gas pipe and the tunnel In addition, the air mortar needs to ensure air permeability so that gas leakage can be detected promptly. The above-mentioned value was set as a necessary air permeability coefficient.

(3) Keeping the amount of heat generated by curing low: 60 ° C or less The peak of the heat generation temperature of air mortar is set to a temperature lower than 60 ° C, which is the softening point of the undercoat between the steel pipe surface of the PLP coated steel pipe and the plastic. Therefore, it is necessary to prevent the plastic coating from shifting. It was also considered to suppress the elongation of the steel pipe during piping.

(4) Conductivity and no generation of precipitates When deposits with high electrical resistance called electrocoating adhere to the surface of the detection probe, it becomes difficult for current to flow through the probe, and anticorrosion using the probe It interferes with management.
Therefore, it is necessary to select an air mortar formulation that does not generate electrocoating. Of the fine aggregates, limestone is likely to be electrocoated and unsuitable.

(5) It is preferable to use a stable material which is excellent in filling property and does not generate voids and does not generate breathing, defoaming and the like.
(6) No material separation occurs because it is preferable to use a stable material that does not result in poor blending.

  FIG. 2 is a table showing the results of demonstrating the blending of mortar 14 that satisfies the above-described conditions. 2 (A) to (C) show blends that satisfy the conditions, and (D) shows a conventional blend. Hereinafter, each formulation in FIG. 2 will be described.

  Conventionally, air mortar was manufactured with ground equipment using the formulation shown in FIG. 2D as a reference formulation, and was pumped into the shield with a pump. Since the viscosity of air mortar is high, a maximum pressure of about 1000 m was a standard for one time. When pumping more than this, it was necessary to install a considerable number of relay pumps.

  Therefore, in addition to manufacturing the air mortar in the shield as described in the first and second embodiments, the mortar itself has a low viscosity to increase the pumpable distance. A mortar formulation was developed. These formulations have been confirmed to satisfy all of the above conditions.

2A to 2C, the blast furnace cement type B is set to 140 to 150 kg / m ³ to suppress the heat generation temperature. As for the fine aggregate, 200 to 250 kg / m ³ of silica-based fine aggregate is mixed so that precipitates are not generated.
The amount of air is set to 55%, and a surfactant foaming agent is used.
In order to perform long-distance pumping, an admixture is added as necessary from the viewpoint of maintaining fluidity and ensuring retarding curing.

  As the foaming agent, a surfactant system having a dilution ratio of 100 times and an expansion ratio of 20 times was used, but even if the dilution ratio and the expansion ratio were changed, there was no significant change in the properties of the air mortar. There is no problem even if animal protein foaming agents are used.

As explained in the first and second embodiments, only blast furnace cement, fine aggregate, kneaded water, and admixture were mixed and stirred with ground equipment to produce mortar 14, which was installed in the vicinity of the placement position in the shield. Pumped to the mixing device 100.
Further, the diluent 43 is foamed and supplied to the mixing apparatus 100.
The mixing apparatus 100 manufactures an air mortar by mixing the mortar 14 and bubbles.

  The fluidity of the mortar 14 having the composition shown in FIGS. 2A to 2C is high, and the pressure of 2000 m × 2B tube × 200 liter / min is about P = 8 kg / cm 2, and the physical property value of the mortar is also stable. It was confirmed by experiment. From this, 3000 m can be pumped from the viewpoint of pumping pressure.

  As mentioned above, the Example of this invention demonstrated the verification result of the mixing | blending of the mortar 14 with high fluidity | liquidity.

It is a figure which shows a mode that the gap filling method in the tunnel which concerns on Embodiment 1 is implemented. It is a table | surface which shows the result of having verified the mixing | blending of the mortar 14 which satisfy | fills a predetermined condition.

Explanation of symbols

  10 Mortar mixer, 11 Blast furnace cement, 12 Fine aggregate, 13 Kneaded water, 14 Mortar, 20 Pressure feed pump, 30 Pressure feed pipe, 41 Foaming agent, 42 Dilution water, 43 Diluent, 50 Pressure feed pump, 60 Compressor, 70 Pressure feed Pipe, 80 pressure air hose, 90 foam cylinder, 100 mixing device, 110 filling hose.

Claims (3)

A method of filling a gap in a tunnel using air mortar,
A mortar pumping step for producing mortar outside the tunnel and pumping it into the tunnel;
Generating bubbles in the tunnel;
An air mortar production step for producing air mortar in the tunnel by mixing bubbles generated in the tunnel with mortar pumped into the tunnel;
Filling the gap with the air mortar;
A method for filling a gap in a tunnel, comprising: Production means for producing air mortar by mixing the bubbles with the mortar is disposed in the tunnel,
In the mortar pumping step, the mortar is pumped to the manufacturing means,
The air mortar manufacturing step includes:
Pumping a diluent for generating the bubbles to the manufacturing means;
Supplying compressed air to the diluent to produce bubbles and mixing with the mortar using the manufacturing means to produce an air mortar;
The method for filling a gap in a tunnel according to claim 1, comprising: A compressor for supplying compressed air is disposed outside the tunnel,
3. The gap filling in the tunnel according to claim 2, wherein the compressor and the manufacturing means are connected by an air hose, and compressed air is supplied to the manufacturing means to foam the diluent in the tunnel. Method.

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