JP4274891B2 - Partial widening method of shield tunnel - Google Patents

Description

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

Conventionally, a widening construction of a shield tunnel has been performed in which the tunnel diameter and the tunnel width of the shield tunnel are expanded from the middle of the extending direction. As such a widening method, a method is known in which the excavation range is expanded using a widening shield machine in which the excavation range of the shield machine and the shield cross section are variable, and a large cross-section segment is assembled behind it. In addition, a method is known in which a certain cross section is excavated by a shield machine, a partially widened segment in which a part of the outer periphery can be extended is installed, and after the shield tunnel is constructed, the width is widened without using the shield machine.
As an example of the latter, for example, in Patent Document 1, an overcutter of a shield machine is used to provide a dugout on the outside of a segment to inject mud, and after the segment is installed, an expansion adapter having a substantially U-shaped cross section is jacked. The expansion shield method that extends in is described.
Further, for example, Patent Document 2 discloses a shield in which ultrahigh pressure water is jetted from a grout hole in front of a widening segment having a substantially U-shaped cross section after the segment is installed and the overhanging direction is excavated, and then the widening segment is extended. The method of partially widening the tunnel by the method is described.
Japanese Patent Publication No. 5-17354 (page 3-4, Fig. 9-10) Japanese Patent Laid-Open No. 58-73693 (page 2-3, FIG. 1-3)

However, the partial widening method for the shield tunnel as described above has the following problems.
In the construction method using the widening shield machine, since a complicated excavation mechanism and a slide mechanism are required, the cost of the shield machine becomes high, and as a result, there is a problem that the construction cost of the widening part becomes expensive.
In the technique described in Patent Document 1, since there is a time difference between the formation of the surplus portion and the extension adapter being extended, the natural ground collapses in the surplus portion, or earth and sand are If they accumulate, there is a problem that they cannot be extended because there is no means for excavating them.
In the technique described in Patent Document 2, a hydraulic jack is provided and pushed out in the extending direction of the widening segment, but the fixed-side segment that is not widened is also subjected to earth and water pressure, and therefore receives high pressure from the side of the widening segment. There is a problem that a high output hydraulic jack is required to move the widening segment. In addition, since a grout hole that penetrates the surface of the widening segment is used as an injection port for ultra-high pressure water, there is a problem in that excavation efficiency cannot be achieved because excavation cannot be performed uniformly in the overhang direction.

  The present invention has been made in view of the above-described problems, and moves the overhang moving portion provided in a part of the segment after the segment is installed toward the natural mountain side and moves it reliably and easily. The purpose is to propose a method of partially widening the shield tunnel.

In order to solve the above-mentioned problem, in the invention described in claim 2, a widening segment is installed as an overhanging moving part that allows a part of the segment to be extended from the inside of the tunnel toward the natural ground side, thereby constructing the tunnel. a portion widening method of shield tunneling performing widening after the prior movement of the overhang moving portion, toward the interior tunnel projecting direction of the projecting movement section, the wider segment of the tool attachment hole with an opening and closing means The excavation means for excavating a natural ground is inserted into the tool mounting opening, and the excavation means is driven to excavate the front of the overhang moving section to form a natural ground excavation section. In addition, a seal member for slidably contacting the joint surface with the adjacent segment is provided on the sliding surface of the overhang moving portion, and each of the overhang moving portions arranged adjacent to the tunnel extending direction is provided once. In movement, the seal member moves by a distance that allows sliding contact with the joint surface with the adjacent segment, and by repeating such overhang movement in the tunnel extending direction, the overhang moving portion is overhanged, and Muddy water is discharged from the natural ground excavation part and widened, and after the widening is completed, the tool mounting port is closed.
According to the present invention, the tool attachment port provided with the opening / closing means is installed before the movement of the overhanging movement unit, and a tool such as an excavation means can be inserted into the tool attachment port. Can be simplified, and there is no hindrance to assembling the segments during shield excavation, and various tools can be replaced and used for widening construction. As a result, it is possible to reliably and easily form a stable ground excavation section for projecting and driving the excavation means toward the ground and performing overhanging movement.
Moreover, since the side surface in the extending direction of the overhanging moving part is used as the sliding surface, the widening can be performed without providing a member that forms the sliding surface such as a wife member.

According to a second aspect of the present invention, in the partial widening method of the shield tunnel according to the first aspect, the tool attachment port is a hole provided on the inner peripheral surface of the overhanging moving part, and is attached to and detached from the hole. The drilling means includes a tubular tool attachment port body that can be engaged, and the excavation means that is attached to the tool attachment port body drives the excavation means to the natural ground side from the hole.
According to the present invention, the overhanging movement part is provided with a hole part that is detachably engaged with the tool attachment port body, and a mechanism for holding the opening / closing means and the excavation means can be provided in the tool attachment port body. The overhanging moving part can have a simple configuration. In addition, since the tool attachment port consists of a hole, when installing the partially widened segment, the outer peripheral surface of the overhanging moving part is blocked by the hole bottom, providing good sealing performance when passing through the tail packing of the shield machine. Can keep.

According to a third aspect of the invention, in the shield tunnel partial widening method according to the first or second aspect , the excavating means includes a high-pressure fluid injection pipe for injecting a high-pressure fluid.
According to the present invention, since the high pressure fluid is ejected from the high pressure fluid ejection pipe, the ground excavation part can be reliably excavated and made muddy without providing a complicated excavation drive mechanism in the tunnel. The overhanging movement of the moving part can be easily performed.

According to a fourth aspect of the present invention, in the partial widening method of the shield tunnel according to the third aspect , when moving the overhang moving part, the water pressure of the ground excavation part, the flow rate of the high-pressure fluid, and the ground A method for measuring the flow rate and density of waste mud from a mountain excavation part and controlling the amount of movement of the overhanging part, the flow rate of the high-pressure fluid and the flow rate of waste mud according to the measurement results.
According to the present invention, the amount of movement of the overhanging moving part according to the water pressure of the natural ground excavation part, the flow rate and density of the high-pressure fluid, and the waste mud flow rate and waste mud density from the natural ground excavation part, Since the flow rate and the waste mud flow rate are controlled, the ground excavation part can be stabilized, and the overhang moving part can be moved while the natural ground is securely held.

In the invention according to claim 5 , the portion of the shield tunnel that widens after the construction of the tunnel by installing the widening segment as the overhanging moving portion that allows the partial extension of the segment from the inside of the tunnel toward the natural mountain side In the widening method, at least when moving the overhang moving portion, a beam member extending in the tunnel extending direction is installed in the vicinity of the end of the fixed segment portion that is in sliding contact with the overhang moving portion, and the moving direction of the overhang moving portion A column member that holds the beam member in a direction intersecting with the beam member is installed to widen the width.
According to the present invention, the support member holds the support segment in the vicinity of the end of the fixed segment portion that is in sliding contact with the overhang moving portion. Therefore, it is possible to prevent a load from being applied to the overhanging moving part from the slidable contact surface with the fixed segment part, and the overhanging moving part can be smoothly moved while maintaining good water stoppage. be able to.

According to a sixth aspect of the invention, in the partial widening method of the shield tunnel according to the fifth aspect , when moving the overhanging moving part, the wife member is moved after temporarily setting a wife member on a sliding part with an adjacent segment. Then, after moving the overhang moving portion of the segment adjacent to the end member side, the end member is removed, and the width is successively increased.
According to the present invention, by temporarily changing the temporary wife members, the overhanging movement portion can be sequentially moved to a predetermined widening position for widening.

According to a seventh aspect of the present invention, in the partial widening method of the shield tunnel according to the fifth aspect, a seal member for slidingly contacting a joint surface with an adjacent segment is provided on the overhang moving portion. Provided on the sliding surface, each of the overhang moving parts arranged adjacent to the tunnel extending direction is moved once, and the seal member moves by a distance capable of sliding contact with the joint surface with the adjacent segment, By repeating such overhanging movement in the tunnel extending direction, a widening method is adopted.
According to the present invention, since the side surface in the extending direction of the overhang moving portion is used as the sliding surface, the widening can be performed without separately providing a member that forms the sliding surface, such as a wife member.

According to the partially widening method of the shield tunnel of the present invention, the construction of the overhanging moving part can be simplified, and the widening construction can be performed by easily inserting a tool such as an excavating means into the tool mounting opening. The ground excavation part is formed and the overhanging movement part can be moved reliably and easily.
Further, according to another method of partially widening a shield tunnel of the present invention, a load applied to the surface where the overhanging moving portion slides in contact with the fixed segment portion can be loaded with the support member, and the overhanging moving portion can be moved smoothly. Since it can do, there exists an effect that the overhanging movement part can be moved reliably and easily.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In all the drawings, even if the embodiments are different, the same or corresponding members are denoted by the same reference numerals, and redundant description is omitted.
[First Embodiment]
Fig.1 (a) is a perspective explanatory view for demonstrating the partial widening method of the shield tunnel which concerns on the 1st Embodiment of this invention. FIG. 1B is a perspective explanatory view as seen from the E direction. 2 to 5 are a DD sectional view, a CC sectional view, a BB sectional view, and an AA sectional view, respectively, in FIG. FIG. 6 is an explanatory diagram viewed from F in FIG.

The partial widening method of the shield tunnel according to the first embodiment of the present invention will be described. This construction method is a construction method in which the partially widened segment 1 is installed in the widening section of the tunnel, and widening is performed from the inside of the tunnel after tunnel construction.
As shown in FIG. 1, the partially widened segment 1 includes a fixed segment 2 that covers a non-widened range, and a widened segment 3 (an overhanging moving portion) that is movable radially outward from a part of the outer periphery of the fixed segment 2. Consists of.
The present embodiment is an example in which a part of the side of the tunnel is extended to the side and widened. Therefore, the fixed segment 2 is assembled in a C-shaped cross section having an opening on the side.
The widened segment 3 extends along the protruding direction from both ends in the circumferential direction of the slide portion 3a having a curvature according to the curvature in the circumferential direction of the fixed segment 2, and can be slidably contacted with the end of the fixed segment 2. It is a member having a substantially U-shaped cross section having extended portions 3b, 3b.
An appropriate water stop material and a joint member are provided at the sliding contact portion between the fixed segment 2 and the widened segment 3 and the adjacent portions in the extending direction. Although not particularly illustrated, a cylindrical non-widened segment closed in the circumferential direction is provided in a section where the width is not widened.

Fig.1 (a) shows the mode of the widening construction part which is implementing this construction method. The diagonally upper left direction in the drawing is the widening end portion 1A, and the diagonally lower right direction in the drawing is the unwidened portion 1C. The widening moving part 1B shows the widening segment 3 that is moving.
This construction method is roughly divided into four steps.
In the first step, the beam extending in the extending direction is in contact with the inner side of the fixed segment 2 and the sliding surface of the overhang portion 3b in the vicinity of the opening in the circumferential direction of the fixed segment 2 in the range where the widening construction is performed. The members 4 and 4 are installed.
As shown in FIGS. 2 and 3, in the unwidened portion 1 </ b> C, the overhanging portion 3 b is sandwiched between the beam member 4 and the widened segment column column 5 a (the column is supported) between the spans of the overhanging portions 3 b and 3 b. Member). As a result, a strut structure that can hold the earth and water pressure applied to the overhanging portion 3b through the fixed segment 2 is constructed.

In the second step, a wife member 3d is formed for forming a sliding surface with another widened segment 3 or a non-widened segment (not shown) adjacent to the extending direction of the widened segment 3 that moves overhang. The end member 3d is detachably attached to the widened segment 3, and is made of, for example, a steel plate and is bolted to the widened segment 3 that moves overhanging.
Then, on the slide portion 3a of the widening segment 3 that moves overhang, the high-pressure fluid jet pipe 6 (excavation means) for excavating the natural ground 100, and the mud pipe 8 for discharging the muddy water in front of the slide section 3a, Is installed. 2 and 4 show how they are installed.
At that time, the widened segment support column 5a is removed as necessary. However, since the column member is installed in the adjacent segment, the earth and water pressure applied to the fixed segment 2 of the partially widened segment 1 which moves overhangs is the beam member. 4 and 4 are supported by the strut members of adjacent segments.

In the third step, high-pressure fluid is ejected from the high-pressure fluid ejection pipe 6, the front of the slide portion 3a is excavated, and the natural ground 100 is made muddy to form the natural ground excavation portion 100A. And the muddy water of the natural ground excavation part 100A is discharged | emitted by the sludge pipe 8, and the widening segment 3 is extended and moved, managing the muddy water pressure of the natural mountain excavation part 100A.
The sludge is taken in by natural pressure sludge using the water pressure outside the segment or forced recovery using negative pressure. In the latter case, for example, depending on the independence of the natural ground, the length of the sludge pipe, the equipment cost, etc. For example, a method of blowing a high-pressure air flow can be properly used.

FIG. 7 is a block diagram illustrating a control mechanism during overhanging movement.
As shown in FIG. 7, a control unit 7 for moving the widening segment 3 while managing the muddy water pressure and the movement amount of the widening segment 3 is provided inside the tunnel.
The slide unit 3 a is provided with a pressure sensor 9 that detects the muddy water pressure of the ground excavation unit 100 </ b> A, and an output signal thereof is input to the control unit 7. A density meter 11 and a flow meter 12 are provided in the flow path of the mud discharge pipe 8, and respective output signals are input to the control unit 7 to detect the density and flow rate of the muddy water.
The control unit 7 is connected to a high-pressure unit 10 for injecting high-pressure fluid from the high-pressure fluid injection pipe 6 and a hydraulic jack (not shown) for moving the widening segment 3 in the extending direction, and drive control signals thereof Can be sent out.
The high-pressure unit 10 is provided with a high-pressure fluid flow meter and density meter.

The configuration of the high-pressure fluid ejection pipe 6 that can be used in the third step will be briefly described.
FIG. 8A is a schematic configuration diagram for explaining the configuration of the high-pressure fluid ejection pipe 6.
The high-pressure fluid injection pipe 6 is supplied with high-pressure water 15 (high-pressure fluid) pressurized from a high-pressure unit 10 connected by a pressure-resistant hose (not shown) and injects it, and performs excavation by a so-called water jet method. Can do. That is, the injection holes 6b and 6b having nozzles of appropriate shapes for injecting the high-pressure water 15 are provided on the side of the tip of the pipe portion 6a that forms the flow path of the high-pressure water 15.
Furthermore, in this embodiment, the excavation bit 6c which can excavate the natural ground 100 is provided in the front-end | tip of the pipe part 6a. The pipe portion 6a can be rotated around an axis by a drive mechanism (not shown), and the excavation bit 6c is provided with an injection hole 6d for injecting the high-pressure water 15 forward in the axial direction.
As a result, when the pipe portion 6a is rotated and the inside of the natural ground 100 is advanced, the excavation bit 6c can penetrate the ground from the tip, and the side and the front are excavated by the excavation action of the high-pressure water 15, The range covered by the water 15 can be made muddy. For this reason, it is possible to perform columnar excavation with the single high-pressure fluid jet pipe 6 around the rotation axis of the pipe portion 6a.
Therefore, the front surfaces of the slide portions 3a can be excavated substantially uniformly by arranging the high-pressure fluid ejection pipes 6 at intervals where the excavation ranges overlap.
Further, the high-pressure fluid ejection pipe 6 has a movable portion and hardly requires power as compared with an excavating means such as a rotary cutter, and therefore can have a simple configuration.
Therefore, it is possible to work efficiently even in a narrow tunnel, and it is easy to replace the widened segment 3 that projects and moves as in this embodiment, or to increase or decrease the number of installations as necessary. There is an advantage.
Moreover, there is an advantage that excavation force can be adjusted according to the state of the natural ground 100 by changing the water pressure and the amount of water of the high-pressure water 15.
Note that the injection hole 6d may not be provided when sufficient excavation can be performed with only the excavation bit 6c.

Here, the installation process and removal process of the high-pressure fluid ejection pipe 6 will be described in detail. In the present embodiment, the high-pressure fluid ejection pipe 6 is installed by providing a tool attachment port including an attachment hole 3A (hole portion) and a tool attachment portion 17 (tool attachment port body).
FIG. 9 is an operation explanatory diagram for explaining the installation process and the removal process of the high-pressure fluid ejection pipe 6 in the third process of the present embodiment.
Fig.9 (a) shows a mode that the tool attachment part 17 is installed in the slide part 3a from the tunnel inner side.
An attachment hole 3A for installing the tool attachment portion 17 is provided inside the slide portion 3a. The mounting hole 3A includes a hole bottom portion 3C that smoothly aligns with the outer surface of the slide portion 3a, and a screw portion 17b that forms a female screw is installed in the opening inside the tunnel.
The tool mounting portion 17 is a cylindrical member made of a steel pipe or the like in which a male screw threadedly engaged with the screw portion 17b is formed at one end, and a seal material 17a made of a rubber packing that can slide on the other end side. However, a valve 18 (opening / closing means) for opening and closing the cylindrical opening is provided in each intermediate portion. Both the sealing material 17a and the opened valve 18 allow a substantially cylindrical tool having a predetermined diameter to be inserted while water is stopped. Examples of the cylindrical tool include the high-pressure fluid injection pipe 6 and the grout injection pipe 19.

Therefore, the tool mounting portion 17 is screwed into the screw portion 17b, and the valve 18 is opened when the tip of the high-pressure fluid ejection pipe 6 passes through the sealing material 17a. Then, the high-pressure fluid jet pipe 6 is inserted into the tool mounting portion 17 and advanced while rotating. Then, the hole bottom 3C is removed by the excavation bit 6c, and the high-pressure fluid ejection pipe 6 is inserted into the natural ground 100 (see FIG. 9B).
At this time, the sealing material 17a stops the water, so that muddy water does not enter the tunnel.
Then, the high-pressure water 15 is jetted and digs forward while rotating. Thereby, the ground excavation part 100A muddy is formed ahead of the slide part 3a.

And the widening segment 3 is extended and moved, maintaining the stability of the natural ground excavation part 100A.
Management of the natural ground excavation part 100A in this embodiment is demonstrated easily. In this construction method, in order to stabilize the natural ground excavation part 100A and to efficiently extend the widening segment 3, the muddy water flow rate is managed in substantially the same manner as the muddy water flow rate at the face of the muddy water shield machine.
Waste water flow rate measured by the density meter 11 and the flow meter 12 with the water supply amount of the high-pressure water 15 as Q ₀ (m ³ / min) and the water supply density as ρ ₀ (in the case of water: 1) (g / cm ³ ). The sludge density is Q ₁ (m ³ / min) and ρ ₁ (g / cm ³ ). Then, the excavated soil water mass M _R (t) excavated during the sampling interval Δt (min) is
M _R = {Q ₁ · (ρ ₁ −1) −Q ₀ · (ρ ₀ −1)} · Δt (1)
It becomes.
On the other hand, (typically, 2.7) _{G S} soil particles true specific gravity and the excavated soil Inuisuna weight _W S (t) is
W _S = {G _S / (G _S −1)} · M _R (2)
It becomes.
Therefore, the excavated land-mount equivalent volume V (m ³ ) is expressed as follows:
V = {(1 + e) / G _S } · W _S (3)
It becomes.
In this way, the excavated land-mount equivalent volume V can be known from the water supply amount Q _{0, the} discharged mud flow rate Q ₁ , _the supplied water density ρ _0, and the discharged mud density ρ ₁ by the equations (1) to (3). Therefore, since the natural ground 100 can be excavated by the volume necessary for the overhang movement, it is efficient without waste. Further, by knowing the excavated land-mount equivalent volume V at every sample interval, the overhang movement distance of the widening segment 3 can be set appropriately, and the overhang movement can be controlled while stabilizing the natural-land excavation section 100A.

In this way, while managing the water supply flow rate (flow rate of the high-pressure fluid), the waste mud flow rate, the water supply density (1 when the high-pressure fluid is simply water), and the muddy water density, the widening segment 3 is set for a predetermined distance required for widening. Move overhang. At that time, since the fixed segment 2 is supported in the vertical direction by the widened segment support column 5a and the beam member support column 5b, the fixed segment 2 does not receive a load from the fixed segment 2 and thus is extended with a relatively low load. There is an advantage that you can.
In order to stably extend and move the widened segment 3, at least four hydraulic jacks on the upper, lower, left and right sides are arranged on the inner peripheral side of the slide portion 3a and the rear end side of the extended portion 3b. It is preferable that the overhang is controlled by the control unit 7 so as to be the same.
Further, in order to improve the excavation efficiency by the high-pressure fluid injection pipe 6, a pressure sensor is installed on the outer peripheral side of the slide portion 3a or in the vicinity of the injection hole 6b, and the excavation efficiency is determined based on the sensor output. It is recommended to control the flow rate of high-pressure fluid and the flow rate of mud.
For example, depending on the condition of the natural ground, it is not necessary to control all of the overhang movement amount, the flow rate of the high-pressure fluid, and the waste mud flow rate, and the excavation may be performed as appropriate.
Moreover, in order to make the natural ground excavation part 100A more stable, a natural ground stabilization treatment material such as bentonite can be mixed in the high-pressure water 15.

When excavation within a predetermined range is completed and the widening segment 3 is moved to the widening position, the high-pressure fluid jet pipe 6 is pulled out to the inside of the tunnel, and when it reaches the position of the sealing material 17a, the valve 18 is closed and then completely pulled out ( (See FIG. 9C).
Then, a grout injection pipe 19 having the same diameter as the high-pressure fluid injection pipe 6 is inserted into the tool mounting portion 17 (see FIG. 9D).
Then, an appropriate grout material 20 is injected from the grout injection pipe 19 in order to make the periphery of the widened segment 3 equal to or higher than the strength of the natural ground 100. After the completion of the injection, the grout injection pipe 19 is retracted, and the grout injection pipe 19 is pulled out in a state where the grout material 20 is filled in front of the valve 18 of the tool mounting portion 17 and stopped, and the valve 18 is closed (FIG. 9 ( e)). On the other hand, the mud discharge pipe 8 is also closed when the mud is replaced with the grout material 20.
After the grout material 20 is solidified, the tool attachment portion 17 and the mud pipe 8 are removed from the inside of the tunnel, and the necessary surface treatment is performed on the inner surface side of the tunnel (see FIG. 9F).
The extracted high-pressure fluid jet pipe 6 and grout injection pipe 19 can be reused in the process of extending the adjacent widened segment 3.
The sludge discharge pipe 8 slides when the valve-equipped sludge discharge pipe 8 is provided so as to branch from the tool mounting portion 17 as shown by a two-dot chain line in FIGS. 9A to 9E. There is an advantage that it is not necessary to provide an opening only for providing the mud pipe 8 in the portion 3a, and the mud efficiency can be improved because mud can be drained in the vicinity of excavation.

In the fourth step, as shown in FIGS. 2 and 5, after the widened segment 3 projects and moves, the beam member struts 5 b are installed between the beam members 4 and 4. Further, the wife member 3d that is no longer needed is removed.
The first to fourth steps are repeated to extend the widening end portion 1A in the extending direction. Then, the end member 3d that has finished its role as a sliding surface is used by being replaced by the widening moving portion 1B.
Further, the post 5b between the beam members is appropriately removed when the joining of the widening segment 3 is finished and the support of the beam member 4 becomes unnecessary. Therefore, the widened segment support column 5a and the beam member support column 5b can be appropriately replaced and reused.

Thus, according to the partial widening method of the shield tunnel according to the first embodiment, after the partial widening segment 1 is installed, the stability of the natural ground 100 is controlled while managing the state of the natural ground excavation part 100A from the inside of the tunnel. By pushing out the widened segment 3 while maintaining the above, the shield tunnel can be widened reliably and easily.
Moreover, since the vicinity of the widened segment is supported by the support member, the widened segment can be extended and moved very smoothly, so that it can be constructed with a simple device.
In addition, since the widened segment 3 is extended and moved while excavating the ground 100, it is not necessary to perform extensive ground improvement or freezing even if the outer periphery of the segment is soft ground or high water pressure ground, etc., thus reducing the construction cost of the widened section In addition, more reliable widening is possible.

A first modification of the first embodiment will be described.
FIG. 10 is a schematic explanatory view in cross-sectional view for explaining a first modification of the first embodiment of the present invention.
In contrast to the first embodiment in which the tool mounting portion 17 is detachable from the inside of the tunnel, this modified example is a socket fixed to the slide portion 3a in place of the mounting hole 3A and the tool mounting portion 17. 21 (tool mounting opening) is provided, and the high-pressure fluid ejection pipe 60 is inserted into the socket 21 so as to be able to advance and retract and rotate freely.
FIG. 10A shows a state in which the high-pressure fluid ejection pipe 60 is housed in the socket 21 without protruding outward from the outer diameter of the slide portion 3a. A sealing material 21a is provided on the inner periphery of the socket 21 to stop water so that soil water does not enter the tunnel. In this state, since the high-pressure fluid injection pipe 60 does not interfere with the shield, the widened segment 3 can be assembled in the shield machine and installed behind the shield machine.
FIG. 10B shows a state of the high-pressure fluid ejection pipe 60 in the third step. Since the high-pressure fluid ejection pipe 60 is held so as to advance and retreat and rotate with respect to the socket 21, it is advanced and rotated toward the natural ground 100 side to excavate the natural ground 100, and after excavating a predetermined amount, FIG. It can be returned to the state. At this time, since it is not necessary to cut the hole bottom 3C, there is an advantage that it is not necessary to provide a drill bit at the tip of the high-pressure fluid jet pipe 60.
However, in order to excavate the natural ground 100 more efficiently, an excavation bit may be provided at the tip. Alternatively, instead of the excavation bit, a forward high-pressure water injection hole may be provided, and the front and sides may be excavated with high-pressure water.
Further, a water stop means similar to the valve 18 may be provided in the middle part of the socket 21 so that the high-pressure fluid ejection pipe 60 can be pulled out or replaced with another cylindrical tool.

A second modification of the first embodiment will be described.
FIGS. 11A and 11B are a schematic cross-sectional view and a schematic perspective explanatory view for explaining a second modification of the first embodiment of the present invention.
In this modified example, a partition plate 30b extending in the circumferential direction of the segment and a partition plate 30c extending in the extending direction of the segment around each of the high-pressure fluid ejection pipes 6 on the projecting surface 30a that is the outer peripheral surface of the slide portion 3a. And a section S is formed. The partition plates 30b and 30c are made of thin plate members such as steel plates.
As shown in FIG. 11A, when the widened segment 3 is assembled behind the shield machine 24, it is temporarily filled with a temporary filling material 30A such as mortar. Therefore, the segments can be assembled in a state where the water is stopped since the tail seal 23 of the shield machine 24 can be slidably contacted with no gap.
The temporary filling material 30A is crushed by the excavation bit 6c of the high-pressure fluid ejection pipe 6 and the high-pressure water when the widening segment 3 is extended, and a state in which the section S as shown in FIG. 11B is exposed is formed.
With such a configuration, when the widening segment 3 is extended and moved, the partition plates 30b and 30c penetrate into the ground and divide into sections S, so that the high-pressure fluid jet pipe 6 acts in the section S to excavate. There is an advantage that the efficiency can be increased. Further, when the high-pressure fluid jet pipe 6 is advanced, the widened segment 3 such as the hole bottom 3C is not crushed as in the above-described embodiment. Therefore, there is an advantage that the widened segment 3 can be manufactured using, for example, a steel plate.

The drainage pipe 8 can be provided in an appropriate section S (see FIG. 11 (b)), or a part of the high-pressure fluid jet pipe can have its function (see FIG. 8 (d)) as described later. .
In the former case, in order to drain mud more efficiently, notches may be provided at appropriate portions of the partition plates 30b and 30c. Thereby, there exists an advantage that it becomes easy to form the flow to the sludge pipe 8 on the overhang | projection surface 30a. As appropriate portions where the cutouts are provided, for example, the four corners of the section S, the intermediate section on the side of the section S, and the like are suitable.

Next, instead of the high-pressure fluid ejection pipe 6, high-pressure fluid ejection pipes 13 and 14 will be described as examples that can be used in the first embodiment and its modifications.
FIG. 8B is an axial sectional view for explaining the high-pressure fluid ejection pipe 13. FIG. 8C is an HH sectional view thereof. FIG. 8D is an axial sectional view for explaining the high-pressure fluid ejection pipe 14.
The high-pressure fluid jet pipe 13 shown in FIG. 8 (b) has a double pipe structure of an outer pipe 13a and an inner pipe 13b, the inside of the inner pipe 13b is a high-pressure water flow path 13B, and the outer pipe 13a and the inner pipe 13b. And a high-pressure air flow path 13A through which high-pressure air 16 (high-pressure fluid) flows. Then, a high-pressure water injection hole 13C is provided from the tip side of the inner pipe 13b toward the outside of the inner pipe 13b, a high-pressure air injection hole 13D is provided around the high-pressure water injection hole 13C, and high-pressure air is surrounded around the high-pressure water 15. In this configuration, 16 flows are formed. Further, similarly to the high-pressure fluid injection pipe 6, a drill bit 6c and an injection hole 6d are provided. The injection hole 6d is configured so that either or both of the high-pressure water 15 and the high-pressure air 16 can be discharged.
By accompanying the high-pressure air 16 around, there is an advantage that excavation with the high-pressure water 15 can increase the excavation force and more efficient excavation.

The high-pressure fluid injection pipe 14 shown in FIG. 8D includes a second inner pipe 14c and a first inner pipe 14b instead of the inner pipe 13b and the outer pipe 13a, and a high-pressure water flow path 14C and a high-pressure air flow path, respectively. 14B can be formed, the high pressure water injection hole 14D is extended from the second inner pipe 14c, and the high pressure air injection hole 14E is provided so as to surround the periphery thereof. And the outer pipe | tube 14a is provided in the outer side of the 1st inner pipe | tube 14b, and the mud flow which inhales the mud of the natural ground excavation part 100A and conveys mud from the mud suction hole 14F provided on the outer pipe 14a A path 14A is formed.
In this case, since the sludge passage 14A has the function of the sludge pipe 8, there is an advantage that it is not necessary to provide the sludge pipe 8 separately.
In the high-pressure fluid injection pipes 13 and 14, as in the high-pressure fluid injection pipe 6, the injection hole 6 d may not be provided when the excavation bit 6 c can perform sufficient excavation.

[Second Embodiment]
The shield tunnel partial widening method according to the second embodiment of the present invention will be described focusing on differences from the first embodiment.
FIG. 12A is a cross-sectional explanatory diagram for explaining a partially widening method for a shield tunnel according to the second embodiment of the present invention. FIG.12 (b) is the G section partial enlarged view in Fig.12 (a).
The partial widening method of the shield tunnel of this embodiment is different from that of the first embodiment in that it is widened without using a wife member. Therefore, instead of the widened segment 3 and the fixed segment 2 of the first embodiment, the widened segment 32 (overhang moving part) and the fixed segment 31 are used. These have the same configuration as the widened segment 3 and the fixed segment 2 except for the configuration of the seal on the side surface in the extending direction.

The fixed segment 31 has, for example, two segment seals 33 arranged in parallel at the center in the thickness direction of the joining surface 31A, which is one side surface in the extending direction. The other side surface of the fixed segment 31 is formed by a grooved flat surface having an appropriate joint shape that can be sealed in contact with the segment seal 33 of the other fixed segment 31 and can be joined in the extending direction.
As the segment seal 33, a seal similar to that used for normal segment assembly can be adopted. For example, a water swelling type synthetic resin sealing material can be adopted.
Further, a sealing material 37 that can be slidably contacted with the widened segment 32 and the slide portion outer peripheral surface 32 c is provided on the C-shaped end surface of the fixed segment 31 so as to connect to the segment seal 33. As the sealing material 37, a synthetic rubber sealing material, which is appropriately formed into a cross-sectional shape, a so-called lip seal or the like can be suitably used.
The segment seal 33 and the sealing material 37 constitute a double seal closed by two parallel strips as a whole.

The widened segment 32 includes a slide portion 32a and an overhang portion 32b having substantially the same configuration instead of the slide portion 3a and the overhang portion 3b of the wide segment 3. On the side surface in the extending direction arranged side by side with the joint surface 31A, a slide portion sliding surface 32A and an overhang portion sliding surface 32B are formed corresponding to the slide portion 32a and the overhang portion 32b.
On the slide part sliding surface 32A, for example, a sealing material 34 composed of two strips is provided at the center position in the thickness direction of the slide part 32a. That is, as shown in FIG. 12B, the sealing material 34 is disposed at a distance d from the outer peripheral surface and the inner peripheral surface in the extending direction of the widened segment 32. And on the overhang part sliding surface 32B, it extends linearly along the vicinity of the overhang part outer peripheral surface 32c.
The seal members 34 that are parallel to each other are bent in the vicinity of the end portion inside the tunnel of the slide portion 32a, and constitute a double seal with a continuous loop as a whole.
As the material of the sealing material 34, a synthetic resin, a synthetic rubber, a composite thereof, or the like can be adopted as long as it is suitable for sliding and can stop muddy water containing earth and sand. In particular, a hard earth and sand sealing material can be suitably employed.

The process of the partial widening method of the shield tunnel of this embodiment will be described.
FIG. 13: is a conceptual diagram for demonstrating the process of the partial widening method of the shield tunnel which concerns on the 2nd Embodiment of this invention.
This construction method omits the second step in the first embodiment and changes the overhang movement amount in the third step. In the present embodiment, widening can be performed without disposing a wife member by setting the overhanging movement of the widening segment 32 to a distance d or less at a time.
In this construction method, as shown in FIG. 12A, in the first step, the beam members 4 and 4 are installed slightly inward from the C-shaped opening of the fixed segment 31, and the widened segment 32 is positioned in the protruding direction. Regardless, the beam member struts 38 are installed to hold the span between the beam members 4 and 4 against soil pressure.
And the overhang | projection means 35 which propels the widening segment 32 is installed in the position which does not interfere with the support | pillar 38 between beam members.
The overhanging means 35 is provided with, for example, a jack cradle 36 for taking a reaction force on the fixed segment 31 side, a holding portion 35b is installed there, and a hydraulic jack 35a is movable on the holding portion 35b in the tunnel extending direction. Alternatively, the hydraulic jack 35a and the jack cradle 36 may be fixed to the holding part 35b by making the holding part 35b travel. A configuration is possible in which the end of the slide portion 32a is pressed with the tip of the hydraulic jack 35a, and the overhanging portion 32b is pressed through the pressing portion 35c to enable overhanging movement.

In the present embodiment, the second step of the first embodiment is omitted.
In the third step, the excavation of the natural ground 100 is exactly the same, so the description thereof is omitted, and the overhanging movement is briefly described with reference to FIG.
First, as shown in FIG. 13 (a), the segments _{S 2} adjacent to the segment _{S 1} of the non-widened portion 1C distance d to overhang move. Then, move the overhanging section 35 in the arrow direction shown in FIG. 13 (b), advancing the segment S ₃ adjacent to the segment S ₂ by distance d.
Next, move the overhang section 35, advancing the segment _{S 4} adjacent to the segment _{S 3} by a distance d (see FIG. 13 (c)). Then, move the overhanging section 35 as shown in the direction opposite to the extending direction in the direction of the arrow in FIG. 13 (d), to advance the segment S ₃ by distance d.
Thus, it is possible to advance the segment S ₃ distance 2d only.
In this way, the movement of the overhanging means 35 in the extending direction can be repeated, and a specific segment can be advanced by an integral multiple of the distance d while always keeping the overhang amount of the adjacent segment at the distance d. Thereby, widening can be performed over a desired length in the extending direction.
In the present embodiment, since the projecting means 35 can be moved while the beam member struts 38 are installed, the beam member struts 38 can be installed without changing until the end of widening.
In addition, although it is the overhang | projection amount d, if the installation position in the slide part sliding surface 32A of the sealing material 34 is brought close to the segment inner surface side, the overhang amount can be increased.

  According to the construction method of the present embodiment, as long as the projecting shape is a shape in which both ends gradually project, it is not necessary to use a wife member. Thus, the installation of the wife member and the replacement work can be omitted, and the widening can be performed by repeating the movement of the overhanging means 35 and the overhanging movement by the overhanging means 35. Therefore, since the amount of movement at one time is small, excavation and overhanging movement of natural ground can be performed on a small scale, so that there is an advantage that widening construction can be surely performed even with a relatively small construction facility.

  In the above description, the excavation means has been described in the case where the high-pressure fluid injection pipe and the excavation bit are provided at the tip of the excavation means. Absent. For example, it is possible to employ a rotary cutter whose diameter is increased after coming out from the tool mounting opening to the natural ground side.

  Moreover, in the above description, the example of the case where the overhanging movement part is translated in one direction has been described, but the overhanging movement part has a shape in which two arcs are joined in a substantially L shape in a cross-sectional view, and one end thereof It is also possible to adopt a configuration in which a rotation fulcrum is formed by pin-locking to a fixed segment. According to such a configuration, the substantially L-shaped corner portion can be projected and moved to the natural ground side by rotational movement around the rotation fulcrum, so that there is an advantage that means for projecting movement can be simplified.

  In the above description, the example in which a part of the shield tunnel is extended and moved has been described. However, it goes without saying that a plurality of protruding moving parts may be provided in one partial widened segment.

It is an isometric view explanatory drawing for demonstrating the partial widening construction method of the shield tunnel which concerns on the 1st Embodiment of this invention. It is DD sectional drawing in Fig.1 (a). It is CC sectional drawing in Fig.1 (a). It is BB sectional drawing in Fig.1 (a). It is AA sectional drawing in Fig.1 (a). FIG. 3 is an explanatory diagram viewed from F in FIG. 2. It is a block diagram for explaining a control mechanism at the time of overhanging movement of the partially widening method of the shield tunnel of the present invention. It is a schematic block diagram for demonstrating the example of the high pressure fluid injection pipe used for the 1st Embodiment of this invention. It is operation | movement explanatory drawing for demonstrating the installation process and removal process of a high pressure fluid injection pipe in the 3rd process of the 1st Embodiment of this invention. It is a schematic explanatory drawing of the cross-sectional view for demonstrating the 1st modification of the 1st Embodiment of this invention. It is the schematic sectional drawing and schematic perspective explanatory drawing for demonstrating the 2nd modification of the 1st Embodiment of this invention. It is sectional explanatory drawing for demonstrating the partial widening construction method of the shield tunnel which concerns on the 2nd Embodiment of this invention, and its G part partial enlarged view. It is a conceptual diagram for demonstrating the process of the partial widening construction method of the shield tunnel which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

1 Partial widened segment 1A Widening end part 1B Widened moving part 1C Unwidened part 2, 31 Fixed segment 3, 32 Widened segment (overhang moving part)
3A Mounting hole (hole)
3C Hole bottom 3d Wife member 4 Beam member 5a Widened segment support column (post member)
5b, 38 Posts between beam members (post members)
6, 13, 14, 60 High-pressure fluid injection pipe (excavation means)
6c Drilling bit 8 Mud pipe 9 Pressure sensor 11 Density meter 12 Flow meter 14F Mud suction hole 15 High pressure water (high pressure fluid)
16 High pressure air (high pressure fluid)
17 Tool mounting part (Tool mounting port body)
17a, 21a Sealing material 18 Valve (opening / closing means)
21 Socket (tool mounting port)
30A Temporary filling material 30b, 30c Partition plate 32A Slide portion sliding surface 32B Overhang portion slide surface 33 Segment seal 34 Seal material 35 Overhang means 37 Seal material 100 Ground 100A Ground mountain excavation portion

Claims (7)

It is a partial widening method for a shield tunnel that widens after building a tunnel by setting up a widening segment as an overhanging moving part that allows part of the segment to be extended from the inside of the tunnel toward the natural mountain side,
Before the movement of the overhang moving part, a tool attachment port provided with an opening / closing means is installed in the widening segment from the inside of the tunnel toward the overhang direction of the overhang moving part,
Insert excavation means for excavating natural ground in the tool mounting opening,
Driving the excavation means to excavate the front of the overhang moving unit to form a natural excavation unit,
Provided on the sliding surface of the overhang moving part is a seal member for slidingly contacting the joint surface with the adjacent segment in the overhang moving part,
Each of the overhang moving portions arranged adjacent to each other in the tunnel extending direction is moved by a distance that allows the seal member to be in sliding contact with the joint surface with the adjacent segment. By repeating in the tunnel extending direction, the overhang moving part is extended, and muddy water is discharged from the ground excavation part and widened.
A partial widening method for a shield tunnel, wherein the tool attachment port is closed after widening is completed. The tool attachment port is composed of a hole provided on the inner peripheral surface of the overhang moving part, and a tubular tool attachment port body that is detachably engaged with the hole,
2. The method for partially widening a shield tunnel according to claim 1, wherein the excavating means mounted on the tool attachment port body drives the excavating means to the natural ground side from the hole. The partial widening method for a shield tunnel according to claim 1 or 2 , wherein the excavation means includes a high-pressure fluid injection pipe for injecting a high-pressure fluid. When moving the overhang moving part,
Measure the water pressure of the natural ground excavation part, the flow rate of the high pressure fluid, the waste mud flow rate and the waste mud density from the natural ground excavation part,
The partial widening method for a shield tunnel according to claim 3 , wherein the moving amount of the overhanging moving part, the flow rate of the high-pressure fluid, and the waste mud flow rate are controlled in accordance with the measurement results. It is a partial widening method for a shield tunnel that widens after building a tunnel by setting up a widening segment as an overhanging moving part that allows part of the segment to be extended from the inside of the tunnel toward the natural mountain side,
At least when moving the overhang moving portion, a beam member extending in the tunnel extending direction is installed in the vicinity of the end of the fixed segment portion that is in sliding contact with the overhang moving portion, and in the direction intersecting the moving direction of the overhang moving portion. A partial widening method for a shield tunnel, characterized in that a pillar member for holding a beam member is installed and widened. When moving the overhang moving part, move the temporary member in the sliding part with the adjacent segment after moving,
The partial widening method for a shield tunnel according to claim 5 , wherein after extending the overhanging moving portion of the segment adjacent to the end member side, the end member is removed and the widening is sequentially performed. Provided on the sliding surface of the overhang moving portion is a seal member for slidingly contacting the joint surface with the adjacent segment in the overhang moving portion,
Each of the overhang moving parts arranged adjacent to the tunnel extending direction is moved once, and the seal member is moved by a distance capable of sliding contact with the joint surface with the adjacent segment,
6. The method of partially widening a shield tunnel according to claim 5 , wherein widening is performed by repeating such overhang movement in the tunnel extending direction.

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