JP2007002560A - Tunnel widening method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tunnel widening method capable of improving construction efficiency by simultaneously performing both the excavation of the periphery of an area to be widened and the reinforcement of the periphery of the area to be widened, reducing construction costs, and reliably preventing ground collapse. <P>SOLUTION: The tunnel widening method uses an excavation means 1 provided with a casing 10 (an excavation shaft) curved at a prescribed curvature; a drive mechanism 20 mounted to the tip of the casing 10: a cutter 30 rotated by the drive mechanism 20; and a solidifying agent injection means. As inserting the cutter 30 into the ground from a tunnel T and agitating both a solidifying agent injected by the solidifying agent injection means and excavated sediment by means of the cutter, the excavation means 1 is advanced to excavate a curved hole A in the periphery of an area K to be widened. After the excavated sediment in the curved hole A is solidified, the area K to be widened is excavated and removed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a tunnel widening method for widening a tunnel.

  In order to provide an emergency parking zone in a tunnel excavated in the same cross section by the shield method, as a method of partially widening the side of the tunnel, the excavation means is configured by attaching a cutter to the tip of an arc-shaped frozen pipe Then, after excavating this excavation means from the wall surface of the tunnel into the ground, placing a freezing pipe around the widened area of the tunnel, supplying a refrigerant into the freezing pipe, and freezing the ground around the freezing pipe, There is a tunnel widening method in which the tunnel is partially widened by excavating and removing the ground in the widened region from within the tunnel (see, for example, Patent Document 1).

In this tunnel widening method, since the ground strength around the widened region can be increased by freezing the ground around the freezing pipe, it is possible to prevent the ground from collapsing when the widened region is excavated.
Japanese Patent Laying-Open No. 2005-030147 (paragraph 0003, FIG. 8 (b))

However, in the conventional tunnel widening method described above, the excavation means is advanced and the freezing pipe is arranged around the widening area, and then the ground is frozen by circulating the refrigerant in the freezing pipe, so that the construction period becomes long. There is a problem that it ends up.
Moreover, since the cooling device for circulating a refrigerant | coolant in a freezing pipe is needed, there exists a problem that construction cost will become high.
Furthermore, since it is difficult to keep the refrigerant in the freezing tube at a uniform temperature, there is a problem that the ground strength around the widened region cannot be increased uniformly.

  Therefore, in the present invention, the above-described problems are solved, and excavation around the widened region and reinforcement around the widened region are simultaneously performed, so that construction efficiency can be improved and construction cost is further reduced. It is an object of the present invention to provide a tunnel widening method that can reliably prevent the collapse of the ground.

  In order to solve the above-described problems, the present invention provides a drilling shaft that is curved with a constant curvature, a drive device that is attached to the tip of the drilling shaft, a cutter that is rotated by the drive device, and a solidified material for excavated soil. A tunnel widening method for widening a tunnel using a drilling means including a solidifying material injection means for injecting a cutter, wherein the cutter is inserted into the ground from the wall surface of the tunnel, the cutter is rotated, and the drilling shaft is grounded By sequentially inserting into the ground, the step of excavating the excavating means into the ground while stirring the solidified material and excavated earth and sand injected by the solidifying material injecting means with the cutter, and the excavating means excavated into the ground , Excavating a curved hole around the widened area of the tunnel, solidifying the excavated soil in the curved hole, and then excavating and removing the ground in the widened area from inside the tunnel It is characterized in that.

  In this way, the excavation means is excavated from the wall surface of the tunnel into the ground, and the excavated sediment and solidified material are agitated, and the curved hole is excavated around the widened area of the tunnel to solidify the excavated sediment in the curved hole. Accordingly, the ground strength around the widened region can be increased while excavating the curved hole around the widened region, so that the construction efficiency can be improved.

  Moreover, without using a shield machine with a special structure that can simultaneously excavate the widened area during tunnel excavation, it uses the cutter, drive device and solidifying material injection means used in general ground excavation equipment. The tunnel can be widened, and furthermore, unlike the conventional method of freezing the ground, it is not necessary to use a cooling device, so the construction cost can be reduced.

  In addition, the excavation means is excavating while injecting solidifying material into the excavated soil in the curved hole, and the entire area in the curved hole can be uniformly solidified, so that the ground strength around the widened area can be increased uniformly. The collapse of the ground when excavating the area can be reliably prevented.

  In addition, since the drive device for rotating the cutter is attached to the tip of the excavation shaft and the output of the drive device is effectively transmitted to the cutter, the excavation efficiency of the cutter can be improved.

  In the tunnel widening method described above, the output portion of the drive device is fitted around the excavation shaft, and the output portion can be configured to rotate around the excavation shaft.

Thus, by rotating the output part of the drive device around the excavation axis, the output part rotates stably, so that the excavation efficiency of the cutter can be improved.
In addition, as an outer peripheral drive type drive device in which the output unit rotates around the excavation shaft, for example, a hydraulic motor such as a radial piston motor or an axial piston motor can be used.

  In the tunnel widening method described above, the excavation shaft is a hollow tube, and the excavation shaft includes a drive cable for driving the driving device and a solidification material supply pipe for supplying the solidification material to the solidification material injection means. It can be configured to be inserted.

In this way, by inserting the drive cable and the solidified material supply pipe into the excavation shaft, the drive cable and the solidified material supply pipe can be easily laid, and the drive cable and the solidified material supply pipe are damaged during excavation. Can be prevented.
In addition to the drive cable and the solidifying material supply pipe, a soil discharge pipe for discharging a part of the excavated earth and sand may be inserted into the drill shaft.

  In the tunnel widening method described above, the cutter can be configured so as to be able to expand and contract.

  Here, when the excavation means is inserted into the ground from the wall surface of the tunnel, if the segment is attached to the wall surface, the excavation means is inserted into the ground from a through hole formed in the segment. At this time, considering the strength of the tunnel, it is desirable to make the opening area of the through hole narrow, but the cutter of the excavation means needs to be downsized along with the opening area of the through hole, and the diameter of the curved hole is small. Therefore, the excavated soil to be solidified is reduced, and the ground strength around the excavation area cannot be sufficiently increased.

  Therefore, by configuring the cutter so that the diameter can be increased and reduced, the diameter of the cutter can be reduced when passing through the through hole of the segment, and the curved diameter can be increased by excavating the cutter after passing through the through hole. The strength of the ground around the excavation area can be sufficiently increased by excavating a large-diameter curved hole and solidifying the excavated sediment in the curved hole. Can do.

  In the tunnel widening method described above, the excavation means excavated in the ground is penetrated into the tunnel, the cutter, the driving device and the solidifying material injection means are removed from the excavation means in the tunnel, and the excavation shaft is left in the curved hole. Can be configured.

In this way, by allowing the excavating means excavated in the ground to penetrate into the tunnel, the cutter, the drive device, and the solidification injection means can be easily removed from the excavation shaft and recovered in the tunnel.
The excavation shaft from which the cutter, the driving device, and the solidification injection means are removed can be reinforced around the widened region by leaving the excavation shaft as a core material in the curved hole.

  In the tunnel widening method described above, after excavating the curved hole, the excavating means can be collected from the curved hole into the tunnel, and the core material can be inserted into the curved hole.

  In this way, after excavating the curved hole, the excavating means can be collected from the curved hole into the tunnel, and the core material thicker than the excavating shaft can be inserted into the curved hole by inserting the core material into the curved hole. Therefore, the periphery of the widened region can be reliably reinforced.

  In addition, it is not necessary to remove the cutter or drive device from the excavation shaft and leave the excavation shaft in the curved hole after excavation of the curved hole, so that it is not necessary to penetrate the excavation means that have been excavated into the ground. As a result, it is not necessary to form a through hole in the tunnel segment for allowing the excavating means to penetrate into the tunnel, so that a decrease in the strength of the tunnel can be reduced. Moreover, since it is not necessary to excavate the excavating means toward the through hole of the segment with high accuracy, construction management can be easily performed.

According to the tunnel widening method of the present invention, while injecting a solidifying material into excavated soil, a curved hole is excavated around the widened region of the tunnel, and the excavated soil in the curved hole is solidified, thereby surrounding the widened region. Since the ground strength around the widened area can be increased while excavating the curved hole, the construction efficiency can be improved.
Moreover, since various apparatuses used for a general ground excavation apparatus can be used, the construction cost can be reduced.
In addition, it is excavated while injecting solidification material into the excavated soil, and the entire area inside the curved hole can be solidified uniformly to increase the strength of the ground around the widened area, so the collapse of the ground when excavating the widened area Can be surely prevented.
Moreover, since the output of the drive device is effectively transmitted to the cutter, the excavation efficiency of the cutter can be improved.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
First, after describing the excavation means used in the tunnel widening method of the present embodiment, a tunnel widening method using the excavation means will be described.
In the following description, the “front-rear direction” corresponds to the digging direction of the digging means.

[Configuration of excavation means]
1A and 1B are diagrams showing excavation means used in the tunnel widening method of the present embodiment, in which FIG. 1A is a side view, FIG. 1B is a side cross-sectional view of a state in which the cutter has been expanded, and FIG. It is a sectional side view of the state reduced in diameter.
As shown in FIG. 1 (a), the excavation means 1 includes a casing 10 (“excavation shaft” in the claims) that is curved with a constant curvature, and a drive that is attached to the tip portion 11 of the casing 10. Device 20, cutter 30 rotated by driving device 20, solidification material injection means (not shown) for injecting solidification material into excavated earth, and earth discharging means (not shown) for excavating a part of excavated earth And.

  The casing 10 is a hollow tube that is curved around a horizontal axis parallel to the axis of the tunnel to be reinforced with a certain curvature, and can be extended sequentially by adding its base end. It is configured. In addition, the attachment part of the drive device 20 is formed in the front-end | tip part 11 of the casing 10 at linear form.

  As shown in FIG. 1B, the drive device 20 is configured such that the output portion 21 is inserted into the casing 10 by inserting the tip portion 11 of the casing 10 into a through hole 22 formed in the center portion of the output portion 21. It is an outer periphery drive type motor that is fitted on the outside and is configured such that the output portion 21 rotates around the axis of the tip end portion 11 of the casing 10. As the drive device 20, a hydraulic motor such as a radial piston motor or an axial piston motor can be used.

  A drive cable (not shown) for supplying and discharging drive oil for driving the drive device 20 is inserted in the casing 10, and the drive cable connected to the drive device 20 passes through the casing 10. It passes through and is connected to an external hydraulic pump (not shown).

  As shown in FIG. 1B, the cutter body 30 is rotated about the same axis as the output unit 21 by the rotation of the output unit 21 of the drive unit 20 by the cutter main body 31 disposed in front of the drive unit 20. Thus, the ground is excavated by the respective bits 32... Of the excavation surface provided on the front surface of the cutter body 31.

  The cutter body 31 is composed of two plate-like members 33, 33, and the plate-like members 33, 33 are arranged in the longitudinal direction of the cutter 30. Further, the inner end portions of the plate-like members 33 and 33 are connected on the central axis of the output unit 21, and the outer end portions of the plate-like members 33 and 33 are arranged behind the inner end portion. It is inclined to.

Further, each plate-like member 33, 33 is rotatably connected at the connecting portion 34, and the cutter body 31 is folded in the center of the connecting portion 34 from the state of FIG. ). Naturally, the cutter main body 31 can be expanded in the state of FIG. 1B by expanding the plate-like members 33, 33 around the connecting portion 34 from the state of FIG. 1C.
When the diameter of the cutter main body 31 is increased, the outer diameter of the drive device 20 is larger. When the diameter of the cutter main body 31 is reduced, the outer diameter of the drive device 20 is substantially the same.

Here, a configuration for expanding and reducing the diameter of the cutter body 31 will be described.
As shown in FIG. 1B, the cutter 30 includes a cylinder 35 that is inserted into the front end portion 11 of the casing 10 behind the cutter body 31.
The cylinder 35 is configured such that the telescopic rod 35a moves in the front-rear direction with respect to the main body 35b on the central axis of the output unit 21, and the distal end of the telescopic rod 35a of the cylinder 35 has a plate shape. It is connected to the connecting portion 34 of the members 33, 33.
The cylinder 35 is configured to rotate around the same axis as the output portion 21 by a bearing 36 interposed between the outer peripheral surface of the main body portion 35 b and the inner peripheral surface of the tip end portion 11 of the casing 10. ing.
Further, one end of two link members 37, 37 that are rod-like members are rotatably attached to the outer peripheral surface of the main body portion 35b of the cylinder 35. The other end of each link member 37, 37 is On the rear surfaces of the plate-like members 33, 33, the plate-like members 33 are rotatably attached to a substantially central portion in the longitudinal direction.

As shown in FIG. 1B, when the telescopic rod 35a of the cylinder 35 is extended with the cutter body 31 expanded in diameter, the connecting portion 34 is pushed forward. Since the movement in the front-rear direction is restricted by the link members 37, 37 in the substantially central portion in the longitudinal direction of the shaped members 33, 33, and is drawn toward the central axis, as shown in FIG. Each plate-like member 33 and 33 will be in the state folded, and the cutter main body 31 will be diameter-reduced.
When the diameter of the cutter body 31 that has been reduced in diameter is increased, the connecting portion 34 is retracted backward by retracting the expansion / contraction rod 35a of the cylinder 35, contrary to the case of reducing the diameter described above. Since each plate-like member 33, 33 whose movement in the front-rear direction is restricted by each link member 37, 37 is pushed outward, as shown in FIG. 1B, each plate-like member 33, 33 is expanded. Thus, the cutter body 31 is expanded in diameter.

Further, as shown in FIG. 1B, each link member 37 is formed at the front end portion of the through hole 22 formed in the central portion of the output portion 21 of the driving device 20 when the cutter body 31 is expanded in diameter. , 37 are formed at the positions where they enter, and the link members 37, 37 are locked to the output portion 21 by the notches 23, 23.
When the output unit 21 is rotated in a state where the link members 37 and 37 are locked to the output unit 21, the link members 37 and 37 are rotated along with the rotation of the output unit 21. 31 rotates around the same axis as the output unit 21.

The solidifying material injecting means (not shown) is a device for injecting the solidifying material into excavated earth and sand excavated by the cutter 30 and left around the casing 10. A solidifying material storage tank (not shown) installed outside. From the front end opening of the through hole 22 formed in the output portion 21 of the drive device 20 through the solidification material supply pipe (not shown) inserted in the casing 10. It is configured as follows.
In the present embodiment, cement milk is used as a solidifying material for solidifying the excavated earth and sand.
Further, the position at which the solidified material is discharged is not limited. For example, the solidified material may be discharged from the excavation surface of the cutter body 31 or may be discharged from the casing 10 behind the driving device 20.

  The soil discharging means (not shown) is a device for discharging a part of the excavated earth and sand excavated by the cutter 30 to the outside from the excavated hole, and the through hole 22 formed in the output portion 21 of the driving device 20. The excavated earth and sand taken in from the front end opening is discharged through the excavated hole through an earth pipe (not shown) inserted in the casing 10.

  In the excavation means 1 having the above-described configuration, the cutter body 31 of the cutter 30 is inserted into the ground, the cutter 30 is rotated by the driving device 20, and the casing 10 is sequentially inserted into the ground, thereby excavating the ground. Can be used to drill a curved hole. Further, while excavating the ground, the solidifying material is injected into the excavated sediment by the solidifying material injection means, the excavated sediment and the solidified material are agitated by the cutter 30, and part of the excavated soil is discharged by the soil discharging means. be able to.

[Tunnel widening method]
Next, a tunnel widening method for widening a tunnel using the excavating means 1 will be described.
2A and 2B are diagrams showing a state in which an entrance hole and an exit hole are formed in the segment in the tunnel widening method of the present embodiment, where FIG. 2A is a front sectional view and FIG. 2B is a diagram showing an inner wall surface of the segment. It is. 3A and 3B are diagrams showing the tunnel widening method of the present embodiment, in which FIG. 3A is a front sectional view of a mode in which the excavating means is excavated in the ground, and FIG. 3B is a diagram after excavating a curved hole in the ground. FIG. 4A and 4B are diagrams showing the tunnel widening method of the present embodiment, in which FIG. 4A is a diagram showing the inner wall surface of a segment after excavating a curved hole, and FIG. FIG.

In the present embodiment, as shown in FIG. 2A, a case will be described in which the side portion of the tunnel T is partially widened in order to provide an emergency parking zone in the tunnel T excavated in the same cross section by the shield method. .
In the following description, a space in which the tunnel T is widened is indicated as a widened region K. A segment S is attached to the wall surface of the tunnel T as a primary lining beforehand.

First, as shown in FIGS. 2A and 2B, the entrance hole S <b> 1 and the exit hole S <b> 2 are made to penetrate the side portion on the widened region K side in the segment S at a predetermined interval in the vertical direction.
The upper inlet hole S1 is a through hole for inserting the excavating means 1, and the lower outlet hole S2 is a through hole for allowing the excavating means 1 advanced into the ground to enter the tunnel T. Therefore, the vertical interval between the inlet hole S1 and the outlet hole S2 is set in accordance with the interval between both ends when the casing 10 is disposed in the ground (see FIG. 3B).
Further, the inlet hole S1 and the outlet hole S2 are arranged in parallel at a predetermined interval in the extending direction of the tunnel T so as to correspond to the width of the widened region K in the extending direction of the tunnel T.
In addition, in order to prevent inflow of earth and sand and groundwater from the entrance hole S1 and the exit hole S2, a lid F is fitted and closed in each of the entrance holes S1,.

Subsequently, as shown in FIG. 3A, the excavating means 1 is installed in the tunnel T, the cutter 30 is passed through the entrance hole S1 from which the lid F is removed, and the cutter 30 is inserted into the ground.
At this time, the support frame 2 for supporting the excavation means 1 is installed in the tunnel T, and the casing 10 is guided by the guide member 3 attached to the support frame 2 and can move in the axial direction. It has become.

Further, when the cutter 30 is allowed to pass through the inlet hole S1, as shown in FIG. 1 (c), the cutter body 31 is allowed to pass while being reduced in diameter.
In this way, the entrance hole S1 only needs to be formed in a size that allows the cutter body 31 having a reduced diameter to pass therethrough, and the opening area of the entrance hole S1 can be reduced. Can be reduced.

As shown in FIG. 3A, the cutter 30 is passed through the inlet hole S1, and after the cutter body 31 is expanded in diameter, the driving device 20 is started and the cutter 30 is rotated to bring the casing 10 into the ground. By sequentially inserting, the excavating means 1 is excavated in the ground.
Further, while excavating the excavating means 1, the solidifying material is injected into the excavated soil from the solidifying material injecting means (not shown), and the excavated earth and solidified material are agitated by the cutter 30, and the earth discharging means (not shown). ) To remove part of the excavated soil.

The casing 10 is inserted into the ground by being pushed out by the hydraulic jack 4 provided on the support frame 2.
In addition, by inserting the packer P into the inlet hole S1, inflow of earth and sand or groundwater from the gap between the inlet hole S1 and the casing 10 can be prevented.

In the excavating means 1 of the present embodiment, as shown in FIG. 1A, the driving device 20 that rotates the cutter 30 is attached to the tip portion 11 of the casing 10, and the output of the driving device 20 is relative to the cutter 30. Communicated effectively. Furthermore, the output part 21 of the drive device 20 is fitted on the tip part 11 of the casing 10, and the output part 21 rotates stably around the axis of the casing 10. Thus, in the excavation means 1 of this embodiment, the excavation efficiency of the cutter 30 can be improved.
In addition, since the drive cables, the solidification material supply pipe, and the discharge pipe (not shown) are inserted into the casing 10, the pipes can be prevented from being damaged during excavation.
Furthermore, since the outer diameter of the casing 10 is smaller than the outer diameter of the cutter body 31 and most of the excavated soil can be left around the casing 10, the amount of soil discharged by the soil discharging means is very small. It has become.

  Then, as shown in FIG. 3A, a curved hole A having an inner diameter larger than the outer diameter of the casing 10 is excavated around the widened region K of the tunnel T by the excavating means 1 that has been excavated in the ground. Since the solidified material is injected into the excavated sediment in the curved hole A and stirred by the cutter 30, the excavated sediment in the curved hole A is solidified after a predetermined time has passed, and the periphery of the casing 10 is By improving the ground, the ground strength will increase.

Thus, since the ground strength around the widened region K can be increased while the curved hole A is excavated around the widened region K, the construction efficiency is improved.
Moreover, since the excavating means 1 injects the solidification material into the excavated sediment and proceeds while stirring the excavated sediment and the solidified material, the excavated sediment in the entire curved hole A can be uniformly solidified.
Furthermore, the cutter 30 can excavate a large-diameter curved hole A by increasing the diameter of the cutter main body 31 after passing through the inlet hole S1, and the amount of excavated soil to be solidified increases. The ground strength of can be sufficiently increased.

  Subsequently, as shown in FIG. 3 (b), the excavating means 1 excavated in the ground is penetrated into the tunnel T from the outlet hole S 2 formed in the segment S. Then, the cutter 30 and the driving device 20 are removed from the casing 10 and collected in the tunnel T, and piping (not shown) of the driving cable, the solidification material supply pipe and the earthing pipe is pulled out from the base end side of the casing 10. And collect. At this time, since the cutter 30 and the driving device 20 can be removed in the tunnel T, the removal work can be easily performed.

  Thus, by recovering the cutter 30, the driving device 20, and the piping from the casing 10 and leaving the casing 10 in the ground, the casing 10 can be used as a core material of the curved hole A, and The surroundings can be reinforced.

When the cutter 30 is passed through the outlet hole S2, the cutter body 31 is passed in a reduced diameter (see FIG. 1B). That is, similarly to the entrance hole S1, the exit hole S2 may be formed to have a size that allows the cutter 30 with the diameter of the cutter body 31 to pass through, and the opening area of the exit hole S2 can be reduced. Therefore, a decrease in the strength of the tunnel T can be reduced.
Further, similarly to the entrance hole S1, the packer P is fitted into the exit hole S2, thereby preventing inflow of earth and sand or groundwater from the gap between the exit hole S2 and the casing 10.

Then, similarly to the above-described excavation of the curved hole A, as shown in FIG. 4A, the curved holes A are sequentially excavated using the respective inlet holes S1 and the respective outlet holes S2, and the widened region K is obtained. The ground strength around (see FIG. 3B) is increased.
The curved holes A that are sequentially excavated are excavated so that the adjacent curved holes A overlap, so that a wall-like ground improvement body surrounding the widened region K is formed.

Thereafter, as shown in FIG. 4B, the segment S corresponding to the widened region K is removed, and the ground of the widened region K is excavated from the tunnel T and removed.
At this time, since the excavated earth and sand in the entire area of the curved hole A is uniformly solidified and the ground strength around the widened region K is increased, the collapse of the ground can be reliably prevented.

  Finally, concrete C is placed as a secondary lining on the inner wall surface of the segment S and the inner wall surface of the widened region K to complete the widening of the tunnel T.

  In the tunnel widening method having the above-described configuration, the cutter 30 used in a general ground excavation apparatus is driven without using a shield machine having a special structure capable of simultaneously excavating the widened region K when the tunnel T is excavated. The tunnel T can be widened by using the device 20, the solidifying material injection means and the earth discharging means, and further, it is not necessary to use a cooling device as in the conventional method of freezing the ground, so that the construction cost is reduced. be able to.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. 5A and 5B are diagrams showing a tunnel widening method according to another embodiment, in which FIG. 5A is a front cross-sectional view of a state where an H-shaped steel core is inserted into a curved hole, and FIG. 5B is an H-shaped steel core. It is the figure which showed the inner wall face of the segment of the state which inserted in the curve hole.

  For example, in this embodiment, as shown in FIG. 3B, the casing 10 of the excavating means 1 (see FIG. 3A) is used as the core material of the curved hole A, but as shown in FIG. In addition, the excavation means 1 excavated in the ground is not penetrated into the tunnel T, and after the curved hole A is excavated in the ground, the entire excavation means 1 is pulled out from the entrance hole S1 and recovered. May be configured to insert a core H of H-shaped steel.

In this configuration, since a core material thicker than the casing 10 (see FIG. 3B) can be inserted into the curved hole A, the periphery of the widened region K can be reliably reinforced.
Moreover, since it is not necessary to form an exit hole in the segment S, it is possible to reduce the strength reduction of the tunnel T and to dig the excavating means 1 (see FIG. 1A) toward the exit hole with high accuracy. Therefore, construction management can be easily performed.

  Moreover, in this embodiment, as shown to Fig.4 (a), although the curved hole A is excavated sequentially using the inlet hole S1 and outlet hole S2 which were arranged in parallel, the some excavation means 1 is carried out. (See FIG. 1A) may be arranged in parallel in the extending direction of the tunnel T, and a plurality of curved holes A may be excavated simultaneously. In this configuration, it is not necessary to move the excavating means 1 in the tunnel T, so that the construction efficiency can be improved.

  In the present embodiment, as shown in FIG. 2B, the segment S is made to penetrate the inlet hole S1 and the outlet hole S2. However, in the segment S, the portions corresponding to the inlet hole S1 and the outlet hole S2 are The excavator 1 may be formed of a material and thickness that can be excavated by the cutter 30 (see FIG. 3A), and the excavator 1 may be configured to drill portions corresponding to the inlet hole S1 and the outlet hole S2. Good. In this configuration, since it is not necessary to form a through hole in the segment S in advance, a decrease in the strength of the tunnel T can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS It is the figure which showed the excavation means used for the tunnel widening method of this embodiment, (a) is a side view, (b) is a sectional side view of the state which expanded the cutter, (c) is the state which reduced the diameter of the cutter FIG. In the tunnel widening method of this embodiment, it is the figure which showed the state which formed the entrance hole and the exit hole in the segment, (a) is front sectional drawing, (b) is the figure which showed the inner wall surface of the segment. It is the figure which showed the tunnel widening method of this embodiment, (a) is front sectional drawing of the aspect which excavates the excavation means in the ground, (b) is front sectional drawing after excavating a curved hole in the ground It is. It is the figure which showed the tunnel widening method of this embodiment, (a) is the figure which showed the inner wall surface of the segment after excavating a curved hole, (b) is front sectional drawing after excavating and removing the widening area | region It is. It is the figure which showed the tunnel widening method in other embodiment, (a) is front sectional drawing of the state which inserted the core material of H-section steel in the curved hole, (b) is the core material of H-section steel in the curved hole. It is the figure which showed the inner wall surface of the segment of the inserted state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Excavation means 10 Casing 20 Drive apparatus 21 Output part 30 Cutter 31 Cutter body A Curved hole K Widening area T Tunnel

Claims (6)

A drilling shaft that is curved with a constant curvature;
A drive unit attached to the tip of the excavation shaft;
A cutter rotated by the drive device;
A tunnel widening method for widening a tunnel using a solidification material injection means for injecting solidification material into excavated earth and sand,
By inserting the cutter into the ground from the wall surface of the tunnel, rotating the cutter, and sequentially inserting the excavation shaft into the ground, the solidified material and excavated earth and sand injected by the solidified material injection means Advancing the excavation means into the ground while stirring with the cutter,
The excavation means excavated in the ground excavates a curved hole around the widened area of the tunnel, solidifies the excavated sediment in the curved hole, and then excavates the ground of the widened area from the tunnel. And a step of widening the tunnel.   2. The tunnel widening method according to claim 1, wherein an output portion of the drive device is externally fitted to the excavation shaft, and the output portion is configured to rotate around the excavation shaft. The drilling shaft is a hollow tube;
2. A drive cable for driving the drive device and a solidification material supply pipe for supplying a solidification material to the solidification material injection means are inserted into the excavation shaft. The tunnel widening method according to claim 2.   The tunnel widening method according to any one of claims 1 to 3, wherein the cutter is freely expandable and contractable.   The excavation means excavated in the ground is penetrated into the tunnel, the cutter, the drive device and the solidifying material injection means are removed from the excavation means in the tunnel, and the excavation shaft is left in the curved hole. The tunnel widening method according to any one of claims 1 to 4, wherein:   The excavation means is recovered from the curved hole into the tunnel after the curved hole is excavated, and a core material is inserted into the curved hole. Tunnel widening method described in 1.

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