JP2009228391A - Tunnel construction method, inner mold, tunnel lining body, and tunnel structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tunnel construction method which can inhibit water leakage generated from the construction joint of concrete in a lining body with a simple structure, an inner mold using the construction method, and a tunnel lining body and a tunnel structure constructed by the construction method. <P>SOLUTION: The tunnel construction method comprises a stripping process S20 where an inner mold assembling process S40 where a water stop 45 is retained on the back of the inner mold 28 installed at the rear side of a shield excavator, and an inner mold 28 is installed so as to make a space 27 between the back of the inner mold 28 and the inner peripheral surface 46 of an excavated hole, and an concrete placing process S50 where concrete 52 is placed into the space 27 so that the construction joint of the concrete 52 is located at a position covered with the water stop 45 are alternately repeated while continuously connecting the inner molds 28 in the excavation direction, thereby integrating the concrete 52 placed into the space 27 and the water stop 45 and hardening the concrete, and the inner molds 28 is removed from the water stop 45. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to tunnel construction for constructing a lining body on the inner peripheral surface of an excavation hole excavated using a shield excavator, and particularly to a technique for suppressing water leakage from a concrete joint of the lining body.

  The ECL (Extracted Concrete Lining) method uses a shield excavator to excavate, and in the tail portion of the excavator, the concrete is placed between the inner peripheral surface of the excavation hole and the inner mold frame provided at the rear of the excavator. This is a method of constructing a lining body by placing

FIG. 11 is an enlarged cross-sectional view of the tail portion of the excavator showing the construction process of the lining body by the ECL method.
As shown in FIG. 11, in the ECL method, after the excavator excavates, the shield jack 22 is contracted to provide a space for installing the inner mold frame 28, and the inner mold frame 28 is placed in the space in the drilling hole. While repeating the step S200 of connecting the peripheral surface and the existing inner frame 28 with the gap 27 in the direction of digging and the step S300 of pressing the concrete 52 into the gap 27, the covering 50 Will continue to build.

  However, since the concrete constituting the lining body constructed as described above has a different placement time depending on the installation timing of the inner mold 28, a seam 54 is generated in the lining body 50, and the joint seam is formed. 54 may cause water leakage.

  Therefore, conventionally, as disclosed in Patent Documents 1 and 2, for example, a technique for suppressing water leakage generated from the joint of the lining body has been proposed.

  Patent Document 1 prepares a precast concrete plate embedded so that the reinforcing bar protrudes from the back surface. The precast concrete plate is placed with a gap from the inner peripheral surface of the excavation hole, and concrete is placed in the gap. Thus, a method of constructing a lining body that unifies the primary lining body and the precast concrete plate by embedding the reinforcing bars protruding from the back of the precast concrete as the reinforcing bars of the primary lining body is disclosed. When constructing the work body, the precast concrete plate covers the joint of the concrete from the inner periphery by constructing so that the joint in the tunnel axis direction between the precast concrete plates and the joint of the concrete are displaced. Since it is installed, it is described that the waterproof effect is enhanced.

Further, in Patent Document 2, the lining body is constructed by confirming the stability of the natural ground by the above ECL method, and a sheet is installed on the inner periphery of the lining body, and the secondary lining is performed inside the sheet. A tunnel construction method for constructing concrete is disclosed, and by this construction, a tunnel lining body is constructed in which groundwater that has passed through the joint of the primary lining body is shielded by a sheet and collected into a drainage ditch. The effect is described.
JP-A-5-38117 JP 2006-241800 A

  However, in the construction of the lining body disclosed in Patent Documents 1 and 2, since it is necessary to provide precast concrete and secondary lining concrete inside the primary lining body, the construction cost increases and the construction period is long. Become.

  The present invention has been made in view of the above points, and in constructing a lining body by placing concrete on the inner peripheral surface of a drilling hole excavated using a shield excavator, a simple configuration is used. To provide a tunnel construction method capable of suppressing water leakage from the concrete joints of the lining body, an inner formwork used for the construction method, a tunnel lining body constructed by the construction, and a tunnel structure Objective.

In order to achieve the above object, the present invention is a tunnel construction method for constructing a lining body of cast-in-place concrete on the inner peripheral surface of a tunnel excavated by digging a shield excavator,
In the rear part of the shield excavator, the step of installing the inner mold frame holding the water stop plate on the back surface so that there is a gap between the back surface of the inner mold frame and the inner peripheral surface of the tunnel; Placing the concrete in the gap so that the joint in the tunnel axial direction is located at the position covered by the water stop plate, while continuously connecting the inner mold in the direction of the shield excavator Repeat alternately,
The concrete placed in the gap is integrated with the water stop plate and hardened, and the inner mold frame is removed from the water stop plate by removing the inner mold frame (No. 1 invention).

According to the tunnel construction method of the present invention, the water stop plate is provided integrally with the concrete on the inner peripheral surface of the primary lining body so as to cover the joint seam of the concrete constituting the primary lining body. Leakage from the water is suppressed.
In addition, since the secondary lining can be omitted, it is not necessary to provide precast concrete or secondary lining concrete, and the construction cost can be reduced and the construction period can be shortened.

  The second invention is an inner mold for constructing a lining body by placing concrete on the inner peripheral surface of a tunnel excavated by a shield excavator, and a water stop plate can be attached to and detached from the rear surface. It has a holding part to hold in.

In a third aspect based on the second aspect, the holding portion holds the water stop plate by vacuum suction.
According to the shield excavator of the present invention, it is possible to hold the water stop plate on the back of the inner mold frame when installing the inner mold frame with a simple configuration, and to remove the water stop plate at the time of demolding. It is possible to demold while

  According to a fourth aspect of the present invention, there is provided a tunnel lining body in which an inner peripheral surface of the excavated tunnel is covered with cast-in-place concrete by excavating a shield excavator, and at least a joint line in the tunnel axial direction of the concrete is provided. Is provided with a water stop plate that covers the inner periphery from the inner peripheral side.

  5th invention is a tunnel structure, Comprising: It built by the tunnel construction method of 1st invention, It is characterized by the above-mentioned.

  According to the present invention, in constructing a lining body by placing concrete on the inner peripheral surface of an excavation hole excavated using a shield excavator, with a simple configuration, from the concrete joint of the lining body It is possible to provide a tunnel construction method capable of suppressing the generated water leakage, an inner mold used for the construction method, a tunnel lining body and a tunnel structure constructed by the construction.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a side view of a shield machine 10 used in the tunnel construction method according to the present embodiment.

  As shown in FIG. 1, the shield machine 10 includes a cutter head 12 for excavating earth and sand at the front end, a shield chamber for taking excavated earth and sand on the back side of the cutter head 12, and earth and sand taken into the shield chamber 14. Is provided with a screw conveyor 16 and a sediment transporting conveyor 18 for discharging the soil to the rear of the shield machine 10.

  The shield machine 10 also includes a cylindrical skin plate 20 that extends rearward from the outer periphery of the cutter head 12, and a shield jack 22 and a end frame jack 24 that are installed inside the rear end of the skin plate 20.

  The skin plate 20 has a role of preventing the collapse of the natural ground and withstanding the underground soil water pressure until the tunnel is constructed.

  A plurality of the shield jacks 22 are provided along the inner periphery of the skin plate 20 and extend by pushing the rear end of the jack against the face side end of the existing inner mold when digging (details will be described later). The reaction force obtained as a result is a propulsive force for the shield machine 10 to push the rotating cutter head 12 against the face and advance.

  A plurality of wife frame jacks 24 are provided at positions outside the shield jack 22, and a wife frame ring 26 is attached to the rear end of the wife frame jack 24.

  The wife frame ring 26 can move back and forth by expansion and contraction of the wife frame jack 24 in a state where a gap 27 (hereinafter referred to as a tail void 27) between the inner peripheral surface of the skin plate 20 and the back surface of the inner mold frame is closed. This is for sealing and pressurizing the concrete placed in the tail void 27 (details will be described later). The end frame ring 26 is formed with a filling hole for filling the tail void 27 with concrete, and a concrete pumping pipe for pumping the concrete from the concrete pump is connected to the filling hole (not shown).

  In addition, the shield machine 10 includes an erector device 30 that demolds, moves, and assembles the inner mold frame 28 behind the cutter head 12. The erector device 30 includes an erector main body 32 and a guide rail 34.

FIG. 2 is a cross-sectional view of the erector device 30 in a direction perpendicular to the tunnel axis.
As shown in FIG. 2, the erector main body 32 has, for example, a ring shape, and is disposed so as to extend in the tunnel axis direction at the center of the tunnel by a drive unit 36 including wheels or the like provided on the inner periphery thereof. It is supported so as to be movable back and forth along the guide rail 34.

  A plurality of expansion jacks 38 are provided on the outer periphery of the erector main body 32 so as to expand and contract in the normal direction with respect to the outer peripheral surface of the erector main body 32, and the tip of the inner mold frame 28 can be attached and detached. ing.

  The inner mold 28 has a back surface separated from a natural ground by a gap (tail void 27, see FIG. 1), and concrete is placed and cured in the clearance (tail void 27) to cover the inner peripheral surface of the natural ground. It is a metal formwork for forming a body. The inner mold frame 28 is a curved piece obtained by dividing the cylindrical ring 40 in the circumferential direction (eight divisions in the present embodiment). Depending on the shape and size, for example, types of B type and K type are available. is there.

  The B-type inner mold frame 28b and the K-type inner mold frame 28k are alternately combined in the circumferential direction to form the ring 40. The B-type inner mold frame 28b is inclined such that the end face Tb in the circumferential direction faces the inner circumferential side, and the K-type inner mold frame 28k is arranged so that the end face Tk in the circumferential direction faces the outer circumferential side. It is inclined by the same inclination angle as the end face Tb of the frame 28b.

FIG. 3 is a view showing an expansion / contraction procedure of the expansion / contraction jack when the inner mold 28 is assembled / demolded.
As shown in FIG. 3, when assembling the inner mold 28 in a ring shape, first, the telescopic jack 38 to which the B-shaped inner mold 28b is attached is extended to place the B-shaped inner mold 28b in a fixed position. Next, the telescopic jack 38 to which the K-type inner mold 28k is attached is extended, and the K-type inner mold 28k is installed between the B-type inner mold 28b previously installed. That is, since the end surface of the inner mold frame 28 is inclined as described above, each inner mold frame 28 is closely assembled, and the cast concrete does not flow out of the connecting portion. 40 is formed. The pieces in the circumferential direction of the inner mold 28 and the pieces in the tunnel axis direction can be connected by bolts or the like.

  On the other hand, when the inner mold 28 is removed, the expansion jack 38 to which the K-shaped inner mold 28k is attached is contracted in the reverse procedure of assembly to remove the K-shaped inner mold 28k, Next, the telescopic jack 38 to which the B-type inner mold 28b is attached is contracted to remove the B-type inner mold 28b.

FIG. 4 is a cross-sectional view of the erector apparatus 30 when all the expansion jacks 38 are contracted.
As shown in FIG. 4, when all the expansion jacks 38 are contracted, the B-type inner mold frame 28b is partially overlapped with the outer side of the K-type inner mold frame 28k so as to be folded in the center direction of the erector main body 32. Be turned. And the erector apparatus 30 conveys the inner mold frame 28 in this state.

FIG. 5 is an enlarged cross-sectional view of the inner mold frame 28.
As shown in FIG. 5, the inner mold 28 has a suction pad 42 to which the plate material 41 can be attached and detached on the back side. A hose 44 connected to an external vacuum pump is connected to the suction pad 42, and an object to be sucked by the suction pad 42 by operating the vacuum pump (a water stop plate 45 in this embodiment as will be described later). Can be removed by vacuum suction and stopping the vacuum pump.

  In the tunnel construction method according to the present embodiment, such an inner mold frame 28 is assembled in a ring shape, and a plurality of such inner mold frames 28 are connected in the tunnel axis direction.

Next, a tunnel construction method according to this embodiment using the shield machine 10 will be described.
FIG. 6 is a diagram illustrating a procedure for constructing a lining body by the tunnel construction method according to the present embodiment. In addition, although this figure has shown typically the tunnel upper part behind the shield machine 10, the same process is performed about the whole inner periphery of a digging hole.

  As shown in FIG. 6, in the tunnel construction method according to the present embodiment, the excavation step S10, the demolding step S20, the inner mold form moving step S30, the inner mold form assembling step S40, and the concrete placing step S50, The tunnel lining body is constructed by repeating the above.

  In the excavation step S10, as described above, the cutter head 12 of the shield machine 10 is pressed against the face and rotated, and the rear end 22a of the shield jack 22 is pressed against the face side end of the existing inner frame 28 to extend. By doing so, the ground is dug forward. Here, the digging distance is set to be approximately the same as the width of the inner mold 28 used for construction, for example.

  Further, during excavation, the wife frame jack 24 is also extended so that the position of the wife frame ring 26 does not move with the extension of the shield jack 22.

  After the excavation is completed, the shield jack 22 is contracted, and a new inner mold 28 is installed between the rear end 22a of the shield jack 22 and the face side end 28a of the existing inner mold 28. Secure space.

  In the demolding step S <b> 20, the rearmost inner mold frame 28 of the existing inner mold frame 28 is demolded by the erector device 30. Specifically, the erector main body 32 is moved to the vicinity of the rearmost inner mold frame 28, the telescopic jack 38 is extended, and the rearmost inner mold frame 28 is fixed to the tip thereof. Remove bolts that connect the pieces in the circumferential direction and tunnel axial direction. Then, as described above, after the expansion jack 38 to which the K-type inner mold frame 28k is fixed is contracted, the expansion jack 38 to which the B-type inner mold frame 28b is fixed is contracted, so that the entire circumference at the tail end is The inner mold 28 is removed. After contraction of the expansion jack 38, the concrete adhering to the back surface of each inner mold 28 is peeled off using a stick or the like (Kellen work).

In the inner mold frame moving step S30, the inner mold frame 28 removed by the erector body 32 in the demolding step S20 is moved on the guide rail 34 and conveyed to a new installation position in front.
In the inner mold assembling step S40, the water stop plate 45 is first adsorbed to the suction pads 42 on the back of each inner mold 28 before the inner mold 28 is installed at a fixed position.

  As the water stop plate 45, any material may be used as long as it has water shielding properties and is integrated with concrete when the concrete is cured when installed so as to be in contact with fresh concrete.

  For the water stop plate 45, for example, the water stop plate 45 having the same size as the back surface of the inner mold frame 28 and having the same curvature as the back surface is used. That is, the water stop plate 45 formed in the same shape as the back surface of the inner mold frame 28 is adsorbed by the adsorbing pad 42 along the back surface of the inner mold frame 28.

  In addition, as the water stop board 45, for example, a cement board (smooth board made by Obayashi Corporation) blended with high-strength vinylon fiber or a cement board (Powerlon board made by Kuraray Co., Ltd.) blended with PVA (polyvinyl alcohol) fiber. In the case of using a material having flexibility such as the above, it may not be formed in a curved shape.

  The extending jacks 38 are extended so that each inner frame 28 having the water stop plate 45 adsorbed on the back surface is digging so that a gap is formed between the water stop plate 45 and the inner peripheral surface 46 of the excavation hole. Install in the space secured in S10.

  At this time, as described above, the extension jack 38 to which the B-type inner mold frame 28b is fixed is extended, and then the extension jack 38 to which the K-type inner mold frame 28k is fixed is extended so that the circumference of the inner mold frame 28 is increased. The pieces in the direction and the tunnel axis direction are connected with bolts or the like. As a result, a new inner mold 28 is installed in front of the existing inner mold 28. Then, after the installation of the new inner mold frame 28 is completed, the fixing of the distal end of the extendable jack 38 and the inner mold frame 28 is released, and the expandable jack 38 is contracted. The erector with the telescopic jack 38 contracted is moved to the vicinity of the last inner mold frame 28 to prepare for the next demolding step S20.

  In addition, it is preferable to continue adsorption | suction of the water stop board 45 by the adsorption | suction pad 42 until completion of concrete placement so that it may not be poured by concrete placement in concrete placement process S50 mentioned later.

  In the concrete placing step S50, concrete is placed from the concrete pump to the tail void 27 via the concrete pressure feeding pipe, and the frame jack 24 is gradually contracted along with this placement. At that time, it is preferable that the concrete is shrunk while being pressed through the wife frame ring 26 by the wife frame jack 24 so that the concrete is in close contact with the natural ground. Thereby, the concrete cast in the tail void 27 can be made dense.

  In addition, the concrete is placed on the tail void 27 so that the joint in the tunnel axial direction is positioned to be covered with the water stop plate 45 adsorbed on the back surface of the inner mold 28. That is, the position of the edge 45a in the tunnel axis direction of the water blocking plate 45 and the rear surface 26a of the end frame ring 26 that is the finish surface of the concrete placement are shifted. In addition, after concrete placement, the suction of the water stop plate 45 by the suction pad 42 on the back surface of the inner mold 28 is released. Thereby, the demolding of the inner mold frame 28 in the demolding step S20 can be performed smoothly.

  In this way, by repeatedly performing the excavation step S10, the demolding step S20, the inner mold frame moving step S30, the inner mold frame assembling step S40, and the concrete placing step S50, the concrete sequentially placed on the tail void 27 is obtained. The lining body 50 is constructed on the inner periphery of the excavation hole by being integrated with the water stop plate 45 and cured.

  Note that the tunnel construction method according to the present embodiment is mainly applied to the case where the lining body is constructed on a natural ground where the excavation hole is self-supporting after excavation. Therefore, it is not necessary to arrange reinforcing bars in the lining body.

  Further, in the tunnel construction method according to the present embodiment, a plurality of rings 40 assembled by the inner mold 28 are connected in the tunnel axial direction, and the rearmost inner mold 28 is removed and placed at the forefront. Repeat the process. Here, the concrete at the demolding position needs to be hardened when the inner mold 28 arranged at the end is demolded. For this reason, the number of rings 40 formed by the inner mold 28 is set in consideration so that a sufficient curing time for the concrete can be secured.

  Further, the reaction force of the driving force for digging the shield machine 10 by the shield jack 22 is received by the friction between the back surface of the installed inner mold 28 and the placed concrete, so that the inner mold 28 The number of connections of the ring 40 is set so that the frictional force is greater than the propulsive force required to dig up the machine.

  As described above, according to the tunnel construction method according to the present embodiment, the water blocking plate 45 is held on the back surface of the inner mold 28 provided at the rear part of the shield excavator, and the inner mold 28 is moved to the inner mold. An inner mold assembly step S40 that is installed so that a gap 27 is formed between the back surface of the frame 28 and the inner peripheral surface 46 of the excavation hole, and the concrete 52 is placed in the gap 27, and the joint of the concrete 52 is a water stop plate 45. The concrete placement step S50 in which the concrete is placed so as to be covered with the inner frame 28 is alternately repeated while continuously connecting the inner mold 28 in the digging direction, and the concrete 52 placed in the gap 27 is stopped. The water stop plate 45 is composed of the water plate 45, cured, and removed from the water stop plate 45 to release the inner mold frame 28, thereby removing the inner mold frame 28. Concrete constituting the lining body Out to cover the seam, since it is provided integrally with the concrete on the inner peripheral surface 46 of the lining member, water leakage from the out seam is suppressed.

  In addition, since secondary lining can be omitted, it is not necessary to provide precast concrete or secondary lining concrete as described in Patent Documents 1 and 2 above, which can reduce the construction cost and shorten the construction period. Contribute to.

  Further, since the entire inner periphery of the tunnel is covered with the water stop plate 45, it is excellent in aesthetics, and the interior of the tunnel can be completed at the same time.

  According to the present embodiment, the water stop plate 45 is formed to have the same size as the back surface of the inner mold frame 28, but is not limited thereto, and is formed to be shorter than the width of the back surface of the inner mold frame 28. You may use the thing of the size. That is, it is only necessary that at least the joint of the concrete in the tunnel axis direction can be covered by the water stop plate 45.

  Moreover, when using the water stop plate 45 formed with a short width, the route for placing concrete on the tail void 27 in the concrete placing step S50 may be changed. That is, not only the concrete is placed through the filling hole formed in the end frame ring 26 as described above, but the water stop plate 45 is attached to the suction pad 42 on the back surface of the inner mold frame 28 in the inner mold assembly step S40. In the area of the back surface of the inner mold 28 that is not covered by the water stop plate 45, a filling hole that penetrates the inner back surface of the inner mold frame 28 is formed in advance, and the concrete pressure feeding pipe is By connecting to the filling hole of the inner mold 28, concrete may be placed through the filling hole of the inner mold 28.

  Further, according to the present embodiment, the water blocking plate 45 is continuously provided on the inner peripheral surface of the lining body. However, the present invention is not limited to this, and the existing positions of the aquifer, water vein, etc. are not limited to this. If it is known, the water stop plate 45 may be held only at the portion corresponding to the position. Thereby, the material cost of the water stop board 45 and the effort of construction can be reduced.

  Moreover, you may make it the structure of the elector apparatus 30 of the shield machine 10 used for the tunnel construction method which concerns on this embodiment, and the inner mold frame 28 as follows.

FIG. 7 is a side view showing an erector apparatus 300 in which a part of the inner mold frame 28 is movable in the tunnel axis direction on the erector body 32.
As shown in FIG. 7, the erector main body 32 includes a main frame 32a that moves on the guide rail 34 in the tunnel axis direction, and a subframe 32b that moves in the main frame 32a in the tunnel axis direction.
The main frame 32a is installed so as to surround the guide rail 34, and can move on the guide rail 34 in the tunnel axis direction. The sub-frame 32b is installed on both sides of the main frame 32a, and can move in the main frame 32a in the tunnel axis direction.

FIG. 8 is a cross-sectional view taken along line AA of the main frame 32a shown in FIG.
As shown in FIG. 8, the main frame 32a is provided with a plurality of extension jacks 380a that extend in the vertical direction for assembling and removing the inner mold frame 28 in the vertical direction. The inner mold frame 28 in the vertical direction can be assembled and removed by fixing the inner mold frame 28 to be arranged and expanding / contracting the expansion / contraction jack 380a.

  The main frame 32a is provided with a plurality of extension jacks 380b for assembling and removing the inner mold frame 28 in an oblique direction, and the inner mold frame 28 can be fixed to the tip of the extension jack 380b. It has become. The connecting portion J1 between the extension jack 380b and the main frame 32a is supported so that the extension jack 380b can turn about the connection portion.

  Further, for assembling / demolding the inner mold frame 28 in an oblique direction, a link 382 extending from the erector main body and fixed to the inner mold frame 28 is installed together with the expansion jack 380b. Note that the connecting portion J2 between the link 382 and the erector main body is supported so that the link 382 can turn around the connecting portion as a fulcrum.

  In this way, since the inner mold frame 28 in the oblique direction is fixed by the plurality of extension jacks 380b and the links 382, the inner mold frame 28 in the oblique direction is moved to a predetermined position by expanding and contracting the extension jack 380b. It can be installed stably.

FIG. 9 is a cross-sectional view of the subframe 32b shown in FIG. 7 taken along the line BB.
As shown in FIG. 9, the subframe 32b is provided with a plurality of expansion and contraction jacks 380c that expand and contract in the horizontal direction, and by fixing the tip of the subframe 32b to the inner mold frame 28 that is disposed in the horizontal direction and extending and contracting the jack, The inner mold 28 arranged in the horizontal direction can be assembled and removed.

  FIG. 10 shows a procedure for assembling / demolding the inner mold frame 28 using the erector apparatus 300. FIG. 10 (a) is a diagram of assembling / demolding the inner mold frame 28 by the main frame 32a, and FIG. 10 (b). FIG. 4 is a view of assembly and demolding of the inner mold frame 28 by the subframe 32b.

  As shown in FIG. 10A, when assembling, first, the main frame 32a is moved to a predetermined position, and then the upper and lower inner mold frames 28 and the inner mold frame 28 in the oblique direction are arranged in this order. And the extension jack 380b is extended to assemble each inner mold 28 in a fixed position. Next, as shown in FIG. 10 (b), the subframe 32b is moved to the same position as the main frame 32a, the telescopic jack 380c is extended, and the horizontal inner mold frame 28 is assembled in the diagonal direction already assembled. Insert between inner molds 28. Thereafter, the inner mold frames 28 are connected by bolts or the like, and the inner mold frame 28 is removed from the ends of the extension jacks 380a to 380c, whereby the assembly of the inner mold frame 28 is completed.

  On the other hand, the reverse procedure of assembly is performed at the time of mold removal. That is, the main frame 32a and the subframe 32b are moved to the position of the inner mold frame 28 to be removed, the inner mold frame 28 is attached to the tip of each of the expansion jacks 380a to 380c, and the connection between the inner mold frames 28 is released. First, the telescopic jack 380c is expanded and contracted to demold the horizontal inner mold frame 28, and after demolding, the sub frame 32b is moved in the tunnel axis direction. Next, the expansion / contraction jack 380b is expanded / contracted, the slanted inner mold frame 28 and the expansion / contraction jack 380a are expanded / contracted, and the upper and lower inner mold frames 28 are demolded in this order to complete the demolding.

  Similarly, the inner mold frame 28 assembled / demolded by the erector apparatus is provided with the above-described suction pad on the back surface thereof, and when assembled, the water stop plate is sucked to the suction pad and assembled. When removing the mold, the mold is removed while removing the water stop plate.

It is a side view of shield machine 10 used for the tunnel construction method concerning this embodiment. 4 is a cross-sectional view of the erector device 30 in a direction perpendicular to the tunnel axis. FIG. It is a figure which shows the expansion-contraction procedure of the expansion-contraction jack at the time of assembly and demolding of the inner mold frame. It is sectional drawing of the erector apparatus 30 when all the expansion-contraction jacks 38 are contracted. 3 is an enlarged sectional view of an inner mold frame 28. FIG. It is a figure which shows the procedure of the construction of the lining body by the tunnel construction method which concerns on this embodiment. FIG. 3 is a side view showing an erector apparatus 300 in which a part of an inner mold frame 28 is movable in the tunnel axis direction on the erector body 32. It is AA sectional drawing of the main frame 32a shown in FIG. It is BB sectional drawing of the sub-frame 32b shown in FIG. The procedure for assembling / demolding the inner mold frame 28 using the erector apparatus 300 is shown, in which FIG. (A) is a diagram of assembling / demolding the inner mold frame 28 by the main frame 32a, and (b) is the subframe 32b. It is a figure of the assembly demolding of the inner formwork 28 by. It is an expanded sectional view of the tail part of an excavator which shows the construction process of the lining body by an ECL method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Shield machine 12 Cutter head 14 Shield chamber 16 Screw conveyor 18 Sediment carry-out conveyor 20 Skin plate 22 Shield jack 24 Wife frame jack 26 Wife frame ring 27 Gap (tail void)
28 Inner form frame 28b B-type inner form frame 28k K-type inner form frame 30 Elector device 32 Elector body 32a Main frame 32b Subframe 34 Guide rail 36 Drive part 38 Extendable jack 40 Ring 41 Plate material 42 Adsorption pad 44 Hose 45 Water stop plate 50 lining body 52 concrete 54 joint 300 erector device 380a, 380b, 380c telescopic jack 382 link S10 digging process S20 demolding process S30 inner formwork moving process S40 inner formwork assembling process S50 concrete placing process Tb, Tk end face

Claims (5)

A tunnel construction method for constructing a lining body with cast-in-place concrete on the inner peripheral surface of the excavated tunnel by excavating a shield excavator,
In the rear part of the shield excavator, the step of installing the inner mold frame holding the water stop plate on the back surface so that there is a gap between the back surface of the inner mold frame and the inner peripheral surface of the tunnel; Placing the concrete in the gap so that the joint in the tunnel axial direction is located at the position covered by the water stop plate, while continuously connecting the inner mold in the direction of the shield excavator Repeat alternately,
Tunnel construction characterized in that the concrete cast in the gap is integrated with the water stop plate and cured, and the inner mold frame is removed from the water stop plate by removing the inner mold frame. Method. An inner mold for constructing a lining body by placing concrete on the inner peripheral surface of a tunnel excavated by a shield excavator,
An inner mold frame comprising a holding portion for detachably holding a water stop plate on a back surface.   The inner mold frame according to claim 2, wherein the holding portion holds the water stop plate by vacuum suction. A tunnel lining body in which the inner peripheral surface of the excavated tunnel is lined with cast-in-place concrete by excavating a shield excavator,
A tunnel lining body comprising a water stop plate that covers at least a joint in the tunnel axial direction of the concrete from an inner peripheral side thereof.   A tunnel structure constructed by the tunnel construction method according to claim 1.

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