JP2007031947A - Sealed type tunnel boring machine method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform efficient construction by using a tunnel boring machine (TBM), even in the presence of natural ground associated with a large quantity of sump water and high-pressure groundwater, when a mountain tunnel targeting a bedrock is bored. <P>SOLUTION: The TBM comprises: a bulkhead 6 for partitioning a front section of a body serving as an outer shell; a chamber 7 which is formed between the bulkhead 6 and a face 30, which is to be filled with water, and into which excavation muck is to be taken; a water supply means which is connected to the bulkhead 6 so as to supply the water into the chamber 7; and a mud discharging means for discharging the excavation muck along with the water from the inside of the chamber 7. The water is supplied into the chamber 7 by the water supply means so that the chamber 7 can be filled with the water, and the TBM advances to bore the tunnel, while discharging the excavation muck along with the water from the inside of the chamber 7 by the mud discharging means. When the TBM encounters the natural ground associated with the sump water, the quantity of the water supplied into the chamber 7 by the water supply means is reduced so that water pressure in the chamber 7 can be kept lower than that of the face 30, and the sump water is flown into the chamber 7 from the face 30 and discharged by the mud discharging means, so that the water pressure of the face 30 can be decreased. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hermetic tunnel boring machine method capable of handling even a natural mountain with a large amount of spring water or high-pressure groundwater in the construction of a mountain tunnel for a rock mass.

  As described in Non-Patent Document 1, previously, a tunnel boring machine (hereinafter referred to as TBM) and a shield machine have been clearly distinguished. In other words, the TBM corresponds to a mountain tunnel for the bedrock, and the shield machine corresponds to the urban civil engineering tunnel for the earth and sand mountain.

  Thereafter, in order to cope with soft and bad ground in a mountain tunnel, a shield-type TBM in which elements of a shield machine are incorporated into the TBM has been developed (for example, see Non-Patent Document 1). This shield type TBM is a structure in which the main body structure is completely covered with a shell (fuselage) over the entire length of the captain in the open type TBM before that. Then, as shown in FIG. 4, the excavation of the TBM 101 is performed while opening the face 30 as in the case of the open type TBM, and it is assumed that the face 30 is independent. Further, excavation is carried out by transportation using a belt conveyor or a screw conveyor or fluid transportation using a jet pump with the face 30 opened.

On the other hand, in order to cope with the earth and sand pile mixed with rock in the tunnel of urban civil engineering, a shield excavation machine for rock mass incorporating TBM elements was developed. This shield excavator for rock mass is, for example, a disc cutter used in TBM applied to a previous muddy shield excavator. Then, as shown in FIG. 5, the excavation of the shield machine 102 is similar to the muddy water shield machine, while resisting the face pressure A ₁₀ (the earth pressure and water pressure of the natural ground), It is basically done without moving. The pressing (stabilization) of the face 30 by mud is performed by pressurizing the mud pressure A ₁₁ in the chamber 107 partitioned by the partition wall 106 as A ₁₁ = A ₁₀ + α with respect to the face pressure A ₁₀ (general) Α is about 19.6 kPa). In addition, the excavated soil is carried out through the pipe in a state where the earth and sand are taken in and dissolved in the muddy water.
"TBM Handbook", Japan Tunneling Technology Association, February 2000

  However, when encountering a natural ground accompanied by a large amount of spring water or high-pressure groundwater, the shield type TBM 101 cannot open itself because the face 30 is open. In order to make the face 30 self-supporting, it was necessary to carry out auxiliary construction methods such as drain boring and chemical injection. Further, due to skin peeling from the open face of the face 30 and a large amount of water draining in the open state, the natural ground is disturbed and the TBM 101 may be restrained. In order to avoid this, a similar auxiliary method was necessary. For this reason, if the construction section of a natural mountain with a large amount of spring water or high-pressure groundwater becomes longer or larger, it often depends on the primitive mountain construction method as described above, and requires a lot of time and cost. There were considerable problems in workability such as tunnel excavation process, TBM availability, and construction reliability.

On the other hand, the shield excavator for rock mass 102 fills the chamber 7 with muddy water pressurized to a pressure A ₁₁ larger than the face pressure A ₁₀ , so that the face pressure A ₁₀ is applied in the ground with a large amount of spring water and high-pressure groundwater. It was a system that could not cope at all when exceeding the pressure resistance of shield machine.

  In this way, TBM and shield machine are influencing each other and the range of natural ground that can be dealt with is widening, but there is still a large amount of spring water and high-pressure groundwater in mountain tunnels targeting rocks. No construction method has been established that can be constructed efficiently in response to natural ground.

  An object of the present invention is to efficiently perform construction using a tunnel boring machine even when there is a natural mountain with a large amount of spring water or high-pressure groundwater when excavating a mountain tunnel for rock.

  In order to solve the above problems, the closed tunnel boring machine method of the invention described in claim 1 is a tunnel boring machine method for excavating a mountain tunnel using a tunnel boring machine as shown in FIGS. The tunnel boring machine includes a fuselage (front trunk 4 and rear trunk 5) which is provided behind the cutter head 2 for excavating a natural ground and serves as an outer shell, and a partition wall 6 which partitions the front part of the trunk. A chamber 7 that is formed between the partition wall 6 and the face 30 and is filled with water and into which excavation shear is taken in, and a water supply means that is connected to the partition wall 6 and supplies water into the chamber 7 (water supply pipe 12, water supply) Pump 13 and the like, and mud discharging means (such as a mud pipe 17 and a mud pump 18) for discharging excavated shear together with water from the inside of the chamber 7, and the cutter head The tunnel boring machine (sealed type) is excavated by filling the chamber 7 with water by the water feeding means and filling the chamber 7 with water by the mud draining means. When excavating the tunnel boring machine 1) and encountering a natural ground with spring water, the amount of water supplied by the water supply means is reduced and the water pressure in the chamber 7 is kept lower than the water pressure of the face 30 so that the spring water It is characterized in that it flows into the chamber 7 from the face 30 and is drained by a mud discharge means.

  As described above, the tunnel boring machine forms the chamber 7 filled with water and seals the face 30 without opening the face 30. Therefore, when the tunnel boring machine encounters a natural mountain with spring water, The movement of water on the fall or face can be suppressed. Then, the amount of water fed into the chamber 7 by the water feeding means is reduced, and the water pressure in the chamber 7 is reduced to a pressure lower than the water pressure of the face 30 and maintained. By making the water pressure in the chamber 7 lower than that of the face 30, spring water flows into the chamber 7 from the face 30. Thereby, the water pressure of the face 30 can be reduced, and the tunnel tunnel boring machine can be easily digged. Furthermore, even if the water pressure of the natural ground exceeds the pressure resistance of the tunnel boring machine, the water pressure of the face 30 can be lowered until the pressure becomes equal to or lower than the pressure resistance, and the tunnel boring machine can dig.

  Therefore, when excavating a natural mountain with a large amount of spring water or high-pressure groundwater, it is possible to construct it efficiently using a tunnel boring machine without applying auxiliary methods such as draining boring or injecting chemicals as in the past. it can. In other words, even if it is a mountain tunnel that includes groundwater with a large amount of spring water and high-pressure groundwater in the construction section, the tunnel excavation process is stabilized, the operation rate of the tunnel boring machine is improved, and the construction reliability is ensured. Thus, the construction period can be shortened and the construction cost can be reduced.

  According to a second aspect of the present invention, in the closed tunnel boring machine construction method according to the first aspect, when a natural ground with spring water is encountered, the amount of excavation shear caused by the cutter head 2 is reduced. Features.

  In this way, by reducing the amount of excavation shear generated by the cutter head 2, the amount of excavation shear to be discharged by the mud discharging means is reduced, and the amount of drainage by the mud discharging means can be increased accordingly. And the water pressure in the chamber 7 can be further reduced by increasing the amount of drainage by the mud discharge means.

  According to the present invention, even when encountering a natural mountain with a large amount of spring water or high-pressure groundwater when excavating a mountain tunnel, the tunnel boring machine forms a chamber filled with water, so the face is opened. It is hermetically sealed and can suppress skin removal from the face and movement of water on the face. The amount of water fed into the chamber is reduced to maintain the water pressure in the chamber lower than the water pressure of the face, and the spring water flows into the chamber from the face and is drained by the mud discharge means, thus reducing the water pressure of the face. It is possible to make it. Even if the water pressure in the natural ground exceeds the pressure resistance of the tunnel boring machine, it can be reduced to below that pressure resistance. Therefore, efficient construction using a tunnel boring machine is possible without performing auxiliary construction methods such as drain boring and chemical injection as in the prior art.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
First, the configuration of a sealed tunnel boring machine 1 (hereinafter referred to as a sealed TBM 1) according to the present embodiment will be described. The sealed TBM 1 basically includes the components of a well-known shielded TBM. Furthermore, in order to seal the face without opening it, a component for retaining the face in a known mud shield shield machine is incorporated.

  That is, as shown in FIG. 1, the sealed TBM 1 according to the present embodiment includes a cutter head 2 driven by a cutter motor 3 to excavate a natural ground, and an expansion / contraction provided behind the cutter head 2 and serving as an outer shell. Ensuring the excavation reaction force with the body (front cylinder 4 and rear cylinder 5) of possible multiple cylinder structures, the erector 8 that assembles the segment 31 in a ring shape at the rear of the rear cylinder 5, and the segment 31 assembled at the rear And a shield jack 9 for generating a propulsive force. In addition, a folding jack 10 and a drilling machine 11 are equipped.

  In this embodiment, in order to simplify the device configuration of the sealed TBM 1, components included in the well-known TBM are omitted. That is, a front gripper that holds the front cylinder 4 against the inner wall surface of the existing tunnel, a main gripper that holds the post cylinder 5 against the inner wall surface of the existing tunnel, and a main gripper that ensures excavation reaction force and propulsion force It is not equipped with a thrust jack that generates However, the sealed TBM 1 can be equipped with these components. When these are equipped, the erector 8 has a function of assembling a support, a liner and the like at the rear part of the rear cylinder 5. The thrust jack has a function as a main jack, and the shield jack 9 has a function as an auxiliary jack when the ground is soft and the main gripper cannot secure a reaction force for excavation.

  Further, the sealed TBM 1 is connected to the partition wall 6 that partitions the front portion of the front barrel 4, the chamber 7 that is formed between the partition wall 6 and the face 30 and is filled with muddy water and into which excavation shear is taken in. The water supply means for supplying the muddy water into the chamber 7 and the mud discharge means for discharging the muddy water and the excavation shear from the chamber 7 are equipped. Therefore, it is not equipped with a soil removal device that performs soil removal with the face 30 open like a conventional TBM.

  As shown in FIG. 2, the muddy water and excavation in the chamber 7 are fluid-transported to the processing equipment 28 installed on the ground by the mud discharge means and separated into the mud and excavation sludge by the processing equipment 28. The separated muddy water is stored in the adjustment tank 29 installed on the ground and is circulated again by the water supply means.

  The water supply means includes a water supply pipe 12 disposed from the adjustment tank 29 to the chamber 7 of the sealed TBM 1, a water supply pump 13 interposed in the water supply pipe 12, and water supply valves 14 and 15. A control valve 16 is provided in parallel with the water supply valve 15 on the chamber 7 side.

  The mud draining means includes a mud pipe 17 disposed from the chamber 7 to the treatment facility 28, a crusher 21 interposed in the mud pipe 17, a mud pump 18, a mud valve 20, and the like. . A relay pump 19 is appropriately added to the mud pipe 17 in accordance with the extension of the tunnel. In addition, a spare drainage pipe 22 of a different system from the drainage pipe 17 is connected to the partition wall 6.

  A bypass pipe 23 is provided between the water supply pipe 12 and the mud discharge pipe 17 so as to communicate them in the vicinity of the water supply valve 15 and the mud discharge valve 20. A bypass valve 24 is interposed in the bypass pipe 23, and a part of the muddy water supplied into the chamber 7 through the water supply pipe 12 is bypassed to the side of the mud pipe 17 so that the pressure in the chamber 7 is increased. Used when maintaining a predetermined value.

  A circulation pipe 25 is provided between the water supply pipe 12 and the crusher 21. A circulation pump 26 is interposed in the circulation pipe 25, and a part of the muddy water supplied into the chamber 7 can be supplied to the crusher 21.

  Next, a sealed TBM method using the TBM having the above configuration will be described. In this sealed TBM method, the excavation is basically performed by excavating a natural ground with the cutter head 2, filling the chamber 7 with muddy water by the water supply means, and excavating the muddy water with the muddy water from the chamber 7 with the mud discharge means. While discharging. Then, change the management method of the muddy water pressure in the chamber 7 by dividing it into a construction section where the natural ground is a normal rock, a construction section where the soft ground is bad, and a construction section with a large amount of spring water and high-pressure groundwater. Do. The muddy water pressure in the chamber 7 is managed while controlling the water supply amount and water supply pressure of the water supply means, the amount of excavated soil of the cutter head 2 and the amount of drainage of the mud discharge means.

  First, since the working face 30 is self-supporting in the construction section where the natural ground is a normal rock mass, the water supply into the chamber 7 may be controlled as the amount of water necessary for draining the excavated shear. Therefore, it is not necessary to control the muddy water pressure in the chamber 7 in order to hold the face 30.

  Next, since the face 30 is not self-supporting in the construction section where the natural ground is a soft defective ground, it is dug by the conventional muddy water type shield method. That is, the muddy water pressure in the chamber 7 is increased to a higher pressure than the face pressure, and the face 30 is stabilized. The muddy water pressure in the chamber 7 is controlled by changing the rotation speed of the water pump 13 or changing the opening ratio of the control valve 16.

Then, in the construction section where the natural mountain is accompanied by a large amount of spring water or high-pressure groundwater, the amount of water supplied by the water supply means is reduced, and the water pressure in the chamber 7 is reduced to a pressure lower than the water pressure of the face 30 and maintained at a predetermined pressure. . That is, as shown in FIG. 3, the water pressure A ₀ in the chamber 7 is controlled as A ₀ = A ₁ −β with respect to the water pressure A _{1 of the} face 30. β is a management value for reducing the water pressure of the face 30. The control range of the water pressure in the chamber 7 is set to be within the pressure resistance range of the sealed TBM 1.

  Since the water pressure in the chamber 7 is lower than the water pressure in the face 30, natural spring water flows from the face 30 into the chamber 7. The inflow spring water is discharged by the mud discharge means together with the muddy water supplied by the water supply means and the excavation shear excavated by the cutter head 2.

  Here, the amount of water supplied by the water supply pump 13 is reduced as the amount of spring water in the natural mountain increases. And when the water supply amount of the water supply pump 13 becomes zero, the excavation is discharged only by the spring water. Further, when the amount of spring water in the ground increases, the spring water flows into the chamber 7 up to the maximum capacity of the mud pump 18 and is discharged together with excavation.

  When the amount of spring water in the ground exceeds the maximum capacity of the mud pump 18, the digging speed of the sealed TBM 1 is reduced to reduce the amount of excavation caused by the cutter head 2. The amount of excavation shear to be discharged by the mud discharge means decreases, and the amount of drainage by the mud discharge means increases accordingly.

  If the state of low excavation discharge continues for a long time, or if there is too much spring water and the soil cannot be drained only by drainage, a separate drainage pump is connected to the preliminary drainage pipe 22 to remove a part of the springwater. Discharge outside the tunnel mine and secure excavated soil.

  According to the above embodiment, in the sealed TBM method, the face 30 is sealed and excavated, so when the natural mountain encounters a natural mountain with a large amount of spring water or high-pressure groundwater, the skin from the face 30 is removed. And the movement of water on the face can be suppressed. And by discharging spring water with a mud discharge means, the water pressure of the face 30 can be reduced and the excavation of the sealed TBM 1 can be facilitated.

  Further, by reducing the amount of excavation debris generated by the cutter head 2, the amount of excavation debris to be discharged by the mud discharge means can be reduced, and the amount of drainage by the mud discharge means can be increased accordingly. The water pressure can be further reduced. Moreover, even if the water pressure of the natural ground exceeds the pressure resistance of the sealed type TBM1, the water pressure of the face 30 can be lowered until the pressure becomes equal to or lower than the pressure resistance, and the sealed type TBM1 can dig.

  Therefore, it can be efficiently constructed using TBM without performing auxiliary construction methods such as draining boring and chemical injection as in the prior art. In other words, even if it is a mountain tunnel including a natural mountain with a large amount of spring water and high-pressure groundwater in the construction section, the tunnel excavation process is stable, the TBM operation rate is improved, and construction reliability is ensured. Thus, the construction period can be shortened and the construction cost can be reduced.

  In addition, in the construction of mountain tunnels for bedrock, flammable gas (toxic gas) jets and high-temperature mountains are problematic. However, this problem can also be solved by the fact that the face 30 is sealed or the cooling effect by water.

  In the above embodiment, in order to reduce the muddy water pressure in the chamber 7, the amount of discharged mud is increased after the amount of water supplied is decreased, but the present invention is not limited to this. The water supply amount may be decreased after increasing the amount of discharged mud.

  Further, when the control cannot cope with the rapid pressure fluctuation of the high-pressure groundwater, and the muddy water pressure in the chamber 7 exceeds the proof strength of the sealed TBM 1, an emergency pressure relief valve 27 is connected to the water supply pipe 12, the chamber 7, etc. In addition, mechanical emergency pressure relief may be performed.

  Further, when the water pressure of the face 30 is extremely high and the pump performance becomes large and uneconomical, the water pressure of the face 30 may be lowered in advance by draining boring using the hole drilling machine 11. In addition, it is needless to say that specific detailed structures and the like can be appropriately changed.

It is a schematic sectional drawing which shows the structure of sealed TBM which concerns on one embodiment to which this invention is applied. It is a figure explaining the flow of the fluid in sealed TBM which concerns on one embodiment to which this invention is applied. It is a schematic diagram for demonstrating the relationship between the water pressure of the face in the sealed TBM which concerns on this invention, and the water pressure in a chamber. It is a schematic diagram for demonstrating the relationship between the water pressure of the face in conventional TBM, and the water pressure in a chamber. It is a schematic diagram for demonstrating the relationship between the water pressure of the face in a conventional shield machine, and the water pressure in a chamber.

Explanation of symbols

1 Sealed tunnel boring machine 2 Cutter head 3 Cutter motor 4 Front trunk (body)
5 Rear trunk (torso)
6 Bulkhead 7 Chamber 8 Electa 9 Shield Jack 10 Folding Jack 11 Hole Drilling Machine 12 Water Supply Pipe (Water Supply Means)
13 Water supply pump (water supply means)
14, 15 Water supply valve (water supply means)
16 Control valve (water supply means)
17 Mud discharge pipe (mud discharge means)
18 Mud pump (mud discharge means)
19 Relay pump (mud discharge means)
20 Mud discharge valve (mud discharge means)
21 Crusher (mud draining means)
22 Preliminary drainage pipe (sludge means)
23 Bypass pipe 24 Bypass valve 25 Circulation pipe 26 Circulation pump 27 Emergency pressure relief valve 28 Processing equipment 29 Adjustment tank 30 Face 31 Segment A ₀ Water pressure at face A ₁ (in a mountain tunnel) A ₁ Muddy water pressure in the chamber (in a closed TBM)

Claims (2)

A tunnel boring machine method that uses a tunnel boring machine to dig up a mountain tunnel,
The tunnel boring machine is formed behind a cutter head for excavating a natural ground and serves as an outer shell, a bulkhead partitioning the front of the fuselage, and a space between the bulkhead and the face. And a chamber into which the excavated ladle is taken in, a water supply means connected to the partition wall to feed water into the chamber, and a mud draining means for discharging the excavated ladle together with water from within the chamber,
Excavating the tunnel boring machine while excavating a natural ground with the cutter head, filling the chamber with water by the water supply means, and discharging the excavation debris together with water from the chamber with the mud discharge means And
When encountering a natural mountain with spring water, the amount of water supplied by the water supply means is reduced, the water pressure in the chamber is kept lower than the water pressure of the face, and the spring water flows from the face into the chamber to drain the mud. Sealed tunnel boring machine method characterized by draining by means of   2. The closed tunnel boring machine method according to claim 1, wherein the amount of excavation caused by the cutter head is reduced when encountering a natural ground with spring water.

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