JP2020094458A - Placement method of tunnel lining concrete - Google Patents

Abstract

To provide a placement method of tunnel lining concrete capable of increasing the quality of concrete for a tunnel levee crown part.SOLUTION: A placement method of tunnel lining concrete according to an embodiment comprises the steps of: placing concrete C to each of a pair of side wall parts T2; protruding a cylindrical inspection hole 10 upward from an apex 2a of formwork 2 forming a levee crown part T1; placing the concrete C up to height H at or higher than the apex 2a and at or lower than an upper end 10a of a cylindrical inspection hole 10 protruded upward from the apex 2a; closing the cylindrical inspection hole 10 after placing the concrete C up to the height H; and placing the concrete C more upward than the height H.SELECTED DRAWING: Figure 5

Description

The present invention relates to a method for placing concrete in a tunnel lining.

Conventionally, various methods have been known as a method for placing tunnel lining concrete. Japanese Unexamined Patent Publication No. 2008-88696 describes a method of constructing a tunnel lining. In this construction method, an arch-shaped form frame having a plurality of openable and closable work windows is used. The work window is used for inspection, confirmation of the concrete driving condition, compaction work with a vibrator, and cleaning work of the formwork.

Concrete pouring is carried out from both sides of the lower part of the tunnel toward the upper end of the tunnel. First, concrete is placed between the formwork and the side wall. At this time, the concrete placing pipe is inserted from the work window and the concrete is placed between the formwork and the side wall through the placing pipe. Further, a vibrator is inserted from a work window different from the work window into which the concrete pouring pipe is inserted, and the poured concrete is compacted. At this time, it is possible to visually confirm the concrete pouring condition from the inside of the tunnel through each of the plurality of work windows.

After confirming that the concrete has been cast to a certain height, remove the casting pipe from the work window and close the work window. Then, a placing pipe is inserted into another working window located above the working window (on the side of the top end), and concrete pouring, compaction, and confirmation of the pouring situation are performed in the same manner as above. After placing and compacting both side walls of the tunnel and checking the placement status, the top end of the tunnel will be placed.

A top end first blow-up mouth is formed on the uppermost lap side of the mold, and a top end second blow-up mouth is formed on the uppermost wife side of the mold. When pouring the top of the tunnel, first, the pipe for pouring is inserted into the first blow-up port of the top, and concrete is poured while applying a predetermined pressure, and then the second top of the top is blown up. Insert concrete pipes into the mouth and apply concrete pressure to pour concrete.

A vibrator attached to the tip of a rod-shaped member extending from the winding mechanism located on the end side is provided on the lap side of the top end portion. After the top end is filled with concrete, the vibrator is pulled from the lap side to the wife side by the hoisting mechanism, so that the concrete is compacted from the lap side toward the wife side. A crown window for opening and closing the top end portion is provided on the top surface of the mold. However, since this crown window is closed before the work is started, it is not possible to visually confirm the situation of placing concrete on the top end including the top of the formwork.

Japanese Patent No. 5916353 discloses a construction method for a tunnel lining having a top end portion, a pair of side wall portions, and a pair of arch portions located between each of the pair of side wall portions and the top end portion. ing. In this construction method, the concrete is cast on the pair of side wall portions and the concrete is cast on the pair of arch portions, and then the concrete is cast on the top end portion. When pouring concrete on the top, place concrete up to the window inside the top, then close the window and then place concrete above the window. To do. Since the concrete is cast on the upper part after the window is closed, it is not possible to visually confirm the concrete is cast on the top end including the top of the formwork.

Japanese Patent No. 6240478 describes a concrete pouring method performed by using a tunnel lining formwork. The top of the tunnel lining formwork has a plurality of blow-up casting holes. Concrete is poured from a selected blow-up hole among a plurality of blow-up holes, and the selection of the blow-up hole is made in a regular order. Each of the blow-up casting holes has a circular shape and is closed after the concrete is filled.

JP, 2008-88696, A Patent No. 5916353 Japanese Patent No. 6240478

In the concrete pouring method described above, an opening such as an inspection window is formed on the bottom surface of the mold forming the top end of the tunnel, and the concrete is filled through this opening. However, since the opening must be closed after the concrete is filled from the opening, it is not possible to visually confirm the concrete pouring condition of the top end portion. In addition, since the concrete flow distance at the top of the tunnel is longer than that of other parts, it may not be possible to suppress the material separation of the concrete, and there is a concern that it may cause defects in the concrete at the top of the tunnel. .. If the concrete at the top of the tunnel becomes defective, peeling or the like may occur. Therefore, it is required to improve the quality of concrete at the top of the tunnel.

It is an object of the present invention to provide a method for placing concrete in a tunnel lining that can improve the quality of concrete at the top of the tunnel.

The method for placing concrete in a tunnel lining according to the present invention is a method for placing concrete in a lining tunnel for constructing a tunnel having a top end and a pair of side walls located on both sides of the top end. Then, a step of placing concrete on each of the pair of side wall portions, a step of projecting a cylindrical inspection hole upward from the top of the mold forming the top end, and a step above the top and projecting upward from the top The step of placing concrete to a height lower than or equal to the upper end of the tubular inspection hole, the step of placing concrete to the height and then closing the tubular inspection hole, and the step of placing concrete above the height. And

In this method of placing concrete for tunnel lining, after the concrete is placed on each of the pair of side wall portions, a cylindrical inspection hole is projected upward from the top of the formwork forming the top end. Then, concrete is poured to a height above the top of the formwork and below the upper end of the cylindrical inspection hole. In this concrete pouring, it is possible to pour concrete to a height higher than the top of the formwork, and lean out from the tubular inspection hole upwards to pour concrete into the top end and check the pouring situation. It is possible to Therefore, it is possible to confirm the concrete pouring condition of the top end. Further, it is possible to compact concrete having a height higher than the top of the mold while visually confirming the situation of placing the concrete at a height higher than the top of the form. Therefore, it is possible to reliably remove air bubbles inside the concrete by visually checking the compaction of the concrete above the top of the formwork, that is, above the top of the inner peripheral surface of the tunnel. It is possible to improve the quality of some concrete. Therefore, it is possible to suppress defects in the concrete at the top end. Moreover, since the concrete is poured into the top end in two steps before and after closing the cylindrical inspection hole, the amount of concrete placed into the top end in each step can be reduced. .. Therefore, the material separation of the concrete can be suppressed more reliably, which contributes to further improvement of the quality of the concrete at the top end.

The side wall portion has a pair of side portions and a pair of shoulder portions located between each of the pair of side portions and the top end portion. Is formed, a shoulder blow-up mouth is formed on the bottom surface of the formwork forming the shoulder, and the step of pouring concrete into each of the pair of side wall parts is performed by a pair of side pouring mouths. It may include a step of placing concrete on each of the side portions, and a step of placing concrete on each of the pair of shoulder portions from the shoulder blow-up port. In this case, concrete is poured from the side pouring port to each of the pair of side parts, and then concrete is poured from the shoulder blowing port to each of the pair of shoulder parts. Therefore, since the concrete is poured into the side wall in two steps, the amount of concrete to be poured into the side wall in each step can be reduced. As a result, the material separation of concrete can be suppressed more reliably.

In addition, the above-mentioned method of placing concrete for tunnel lining comprises a step of compacting the concrete placed above after the step of placing the concrete above the height, and the step of placing the concrete in the compacting step. Compaction may be performed by oscillating the vibrator while moving the vibrator inserted in the crushed concrete in the axial direction of the tunnel. In this case, after placing the concrete on the top of the tunnel, the concrete is compacted while moving the vibrator in the axial direction of the tunnel. Therefore, by compacting while moving the vibrator, the concrete at the top of the tunnel can be efficiently compacted.

Further, the above-mentioned method for placing lining concrete may include a step of pulling the tubular inspection hole downward from the top of the mold after the step of closing the tubular inspection hole. In this case, after closing the cylindrical inspection hole, the cylindrical inspection hole can be drawn downward from the top of the mold. Therefore, since the vibrator does not hit the cylindrical inspection hole during compaction of concrete cast above the height, the concrete can be compacted more efficiently.

According to the present invention, it is possible to improve the quality of concrete at the top end of a tunnel.

It is a perspective view which shows roughly the tunnel constructed by the method of placing the tunnel lining concrete which concerns on embodiment. It is a side view of the tunnel of FIG. It is a perspective view which shows the example of the cylindrical inspection hole which protrudes upwards from the formwork used by the method for placing tunnel lining concrete according to the embodiment. It is a longitudinal cross-sectional view of the cylindrical inspection hole of FIG. It is sectional drawing which shows the outline of the driving method of the tunnel lining concrete which concerns on embodiment. FIG. 2 is a perspective view showing an example of a state in which concrete is poured and compacted on the shoulder portion of the tunnel of FIG. (A), (b), (c), (d) and (e) are procedures for projecting a cylindrical inspection hole to the top end of the tunnel of FIG. 1 and placing concrete on the top end. FIG. 5 is a plan view and a vertical cross-sectional view of a cylindrical inspection hole showing FIG. It is a side view of the tunnel showing a state in which a tubular inspection hole is pulled out downward from the top end. It is a side view which shows typically the state which compacts the concrete of the top end part.

Hereinafter, an embodiment of a method for placing concrete in a tunnel lining according to the present invention will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements will be denoted by the same reference symbols, without redundant description. In addition, in order to facilitate understanding, some of the drawings may be simplified or exaggerated, and dimensional ratios and the like are not limited to those illustrated in the drawings.

For the construction of the tunnel T according to the present embodiment, for example, the ground J (see FIG. 5) is excavated and mortar (blast concrete) is sprayed on the inner peripheral surface J1 which is the excavated surface, and then the lining 1 for lining is applied. Install and drive concrete C into it. As an example, the tunnel T is a road tunnel, and the slump value of the concrete C is about 15 cm. FIG. 1 schematically shows the placement of the installed lining center 1 and concrete C according to the present embodiment. As shown in FIG. 1, the lining 1 for lining is used when placing concrete C on the inner circumferential surface J1 of the ground J on which the concrete has been sprayed.

The lining center 1 is provided with an arch-shaped formwork 2 (form group), and a casting space K formed between the inner peripheral surface J1 obtained by excavating the natural ground J and the formwork 2 Concrete C is poured into. After the concrete C is poured, the concrete C is protected (cured) by maintaining the state for a predetermined time.

The lining 1 for lining further includes a gantry 3 that supports the mold 2 from the inside (center side) of the tunnel T, and the gantry 3 can be combined with and separated from the mold 2. The mold 2 is formed in an inverted U shape (horseshoe shape) and is opened downward. The gantry 3 is a portal-type movable gantry, and a rail 3a for guiding the gantry 3 is laid inside the tunnel T along the axial direction D1 (length direction) of the tunnel T.

Therefore, the gantry 3 can move in the axial direction D1 of the tunnel T. The gantry 3 includes a plurality of supporting members 4 that press and support the formwork 2 from the inside of the tunnel T. Each of the plurality of support members 4 is, for example, a mechanical rod jack, and the base end of the support member 4 is connected to the gantry 3 and the tip of the support member 4 is connected to the mold 2.

As shown in FIGS. 1 and 2, the concrete C of the tunnel T constitutes a top end portion T1 and a side wall portion T2 of the tunnel T, and the side wall portion T2 includes a side portion T21 and a shoulder portion T22 of the tunnel T. Is included. In the method for placing lining concrete according to the present embodiment, after placing the concrete C on the side portion T21 and the concrete on the shoulder portion T22, placing the concrete C on the top end portion T1. The installation is done in two steps. The top end portion T1 has a top end lower portion T11 including the upper end of the inner peripheral surface T4 of the tunnel T, and a top end upper portion T12 that is located above the top top lower portion T11 and includes the uppermost portion of the tunnel T.

The mold 2 has a plurality of cylindrical inspection holes 10 projecting upward from the top 2a, and the concrete C is cast into the top end T1 using the cylindrical inspection holes 10. The cylindrical inspection hole 10 is a cylindrical expansive inspection window through which the worker M leans upwards and can visually confirm the concrete C at the top end T1, and is vertically movable. The worker M compacts the concrete C by leaning out from the tubular inspection hole 10 and moving the vibrator V attached to the tip of the linear member V1 while vibrating inside the concrete C, for example. ..

The formwork 2 includes a plurality of inspection windows 2b arranged along the axial direction D1 and the circumferential direction D2 of the tunnel T, a plurality of shoulder blow-out ports 2c facing the shoulder T22 of the tunnel T, and a ceiling of the tunnel T. It is provided with a plurality of top end blowing ports 2d facing the end T1 and a side driving port 2e facing the side T21 of the tunnel T. The inspection window 2b, the shoulder blowing port 2c, the top blowing port 2d, and the side driving port 2e are, for example, all rectangular. Further, a pipe is discharged into the casting space K of the concrete C from the shoulder blow-up port 2c, the ceiling blow-off port 2d and the side pouring port 2e, and the concrete C flows into the casting space K from this pipe. The plurality of shoulder blow-up openings 2c, the plurality of top-end blow-out openings 2d, and the plurality of side-pouring openings 2e are arranged such that the flow distance of concrete C is 2 m or less, for example.

The inspection window 2b may be provided, for example, at a position facing the shoulder portion T22 of the tunnel T or a position facing the side portion T21. The worker M leans out from the inspection window 2b, and the worker M leans out from the inspection window 2b to check the placing condition of the concrete C on the side T21 or the shoulder T22 and tighten the concrete C by the vibrator V. Harden.

Each of the shoulder blowing port 2c and the side driving port 2e is arranged, for example, at a position adjacent to the inspection window 2b. From each of the shoulder blow-up port 2c and the side pouring port 2e, a pipe for supplying the concrete C is taken out, and the concrete C is poured from the pipe to the side wall portion T2. The plurality of shoulder blowing ports 2c and the plurality of side driving ports 2e are arranged side by side along the axial direction D1. For example, each of the shoulder blowing port 2c and the side driving port 2e is arranged at a position adjacent to the even-numbered inspection windows 2b among the plurality of inspection windows 2b arranged along the axial direction D1. However, the number, shape, and arrangement position of the shoulder blow-up port 2c and the side driving port 2e can be appropriately changed.

The top end blowing port 2d is arranged, for example, at a position adjacent to the tubular inspection hole 10. Similarly to the above, a pipe is ejected from the top end blow-up port 2d, and the concrete C is cast from the pipe to the top lower part T11 of the top end T1. A plurality of top end blow-up openings 2d are arranged side by side along the axial direction D1. For example, the top end blowing port 2d is not arranged at a position adjacent to all the tubular inspection holes 10. As an example, the cylindrical inspection holes 10 in which the top end blowing port 2d is arranged and the cylindrical inspection holes 10 in which the top end blowing port 2d is not arranged may be arranged alternately along the axial direction D1. In this way, the number, shape, and arrangement position of the top end blowing ports 2d can be changed as appropriate.

FIG. 3 is a perspective view showing a simplified tubular inspection hole 10. FIG. 4 is a vertical cross-sectional view showing a simplified tubular inspection hole 10. As shown in FIGS. 3 and 4, the cylindrical inspection hole 10 is positioned, for example, on a cylindrical side portion 11 that is vertically movable with respect to the mold 2 and an upper portion of the side portion 11. A lid 12 that allows the tubular inspection hole 10 to be opened and closed, a seal member 13 that surrounds the side portion 11 and is interposed between the side portion 11 and the mold 2, and the side portion 11 is vertically arranged with respect to the mold 2. And a slide mechanism (not shown) for sliding.

The cylindrical inspection hole 10 is, for example, an upper lid type in which a lid portion 12 is provided on an upper portion of the side portion 11. The side portion 11 has, for example, a cylindrical shape. The lid portion 12 has a plurality of valve portions 12a that are swingable in the axial direction D3 of the side portion 11 and a pipe insertion hole 12b formed between the plurality of valve portions 12a. The valve portion 12a is made of, for example, a stretchable material. The valve portion 12a is swingable in the axial direction D3 around the shaft portion 12c extending along the circumferential direction D4 of the side portion 11 in the upper portion of the side portion 11.

In the state where the cylindrical inspection hole 10 is closed, the plurality of valve portions 12a are in close contact with each other along the form 2 (a plane orthogonal to the axial direction D3). The pipe insertion hole 12b is provided at the center of the lid portion 12 in plan view. When the cylindrical inspection hole 10 is closed, the pipe P (see FIG. 7) can be inserted through the pipe insertion hole 12b along the axial direction D3. As a result, it becomes possible to pour concrete C upward from the lid portion 12 with the tubular inspection hole 10 closed. The configuration of the tubular inspection hole 10 is not limited to the configuration including the side portion 11, the lid portion 12, the seal member 13, and the slide mechanism described above, and can be changed as appropriate.

Next, a method for placing concrete for tunnel lining according to the present embodiment will be described. First, as shown in FIG. 5, the formwork 2 is installed so that the placing space K of the concrete C is formed between the excavated natural ground J and the inner circumferential surface J1, and then the side portion T21. The concrete C, the concrete C is cast on the shoulder portion T22, the concrete C is cast on the lower top portion T11, and the concrete C is cast on the upper top portion T12 in this order.

First, as shown in FIG. 6, concrete C is cast on each of the pair of side portions T21 (a step of placing concrete on each of the pair of side portions). At this time, for example, the concrete C is poured into the casting space K from each of the plurality of side casting holes 2e (see FIG. 2), and the concrete C is cast into the side portion T21. Then, the worker M inserts the vibrator V with the linear member V1 into the concrete C of the side portion T21 through the inspection window 2b, vibrates the concrete C of the side portion T21 with the vibrator V, and compacts the concrete C.

Next, the concrete C is placed on each of the pair of shoulders T22 (step of placing concrete on each of the pair of shoulders). For example, concrete C is poured from each of the plurality of shoulder blowing ports 2c into the setting space K to blow the concrete C onto the shoulder portion T22, and the concrete C of the shoulder portion T22 is vibrated by the vibrator V as described above. Then, the concrete C is compacted.

Subsequently, as shown in FIG. 5, a cylindrical inspection hole 10 is projected upward from the top 2a of the mold 2 forming the lower top part T11, and the cylindrical inspection is projected above the top 2a and upward from the top 2a. Concrete C is poured to a height H equal to or lower than the upper end 10a of the hole 10 (step of projecting the cylindrical inspection hole, step of pouring concrete to a height equal to or lower than the upper end of the cylindrical inspection hole). That is, the concrete C is placed on the lower portion T11 of the top end.

As a specific example, as shown in FIG. 5 and FIG. 7A, the tubular inspection hole 10 is opened by swinging each of the plurality of valve portions 12 a downward to open the tubular inspection hole 10. Concrete C is placed around the cylindrical inspection hole 10 from the top end blowing port 2d by projecting upward from the mold 2. At this time, concrete C is poured into the casting space K from the pipe P through the pipe P from the top end blow-up port 2d to the casting space K, and the concrete C is poured until the concrete C reaches the height H. At this time, the operator M leans out from the cylindrical inspection hole 10 and compacts the concrete C with the vibrator V, and confirms the placing condition of the concrete C, whereby the upper end of the inner circumferential surface T4 of the tunnel T is confirmed. The quality of the concrete C at the lower part of the top T11 including is secured.

As shown in FIG. 7B, a state in which each of the plurality of valve portions 12a is swung upward to close the cylindrical inspection hole 10 and the pipe P is inserted into the driving space K from the pipe insertion hole 12b. Then, the sliding movement of the cylindrical inspection hole 10 downward is started (step of closing the cylindrical inspection hole). Then, as shown in FIG. 7(c), the concrete C is cast on the top end T12 and the tubular inspection hole 10 is pulled out downward (concrete above the height H above the concrete H). The step of placing, the step of pulling out the cylindrical inspection hole from the top of the formwork).

Subsequently, as shown in FIGS. 7D, 7E, and 8, the tubular inspection hole 10 is continuously pulled out to the lower side of the form 2, and the upper end 10a of the tubular inspection hole 10 is After lowering to the height of the mold 2, the pipe P is pulled out from the pipe insertion hole 12b and the pipe insertion hole 12b is sealed by the lid member 15.

Then, as shown in FIG. 9, the concrete C cast above the height H (upper end T12 of the top end) is compacted (step of compacting the concrete cast above). At this time, for example, the linear member V1 with the vibrator V is inserted into the concrete C along the axial direction D1, and the vibrator V is inserted to one end of the concrete C in the axial direction D1. Then, while vibrating the concrete C with the vibrator V, the linear member V1 is moved to the other end side in the axial direction D1, and the concrete C is compacted while gradually moving the vibrator V to the other end side in the axial direction D1. .. As described above, after compacting the concrete C on the top tip T12, the concrete C is cured and cured to complete a series of steps.

Next, the function and effect of the method for placing tunnel lining concrete according to the present embodiment will be described in detail. For example, as shown in FIG. 5, in the tunnel lining concrete placing method according to the present embodiment, after the concrete C is placed on each of the pair of side wall portions T2, the mold 2 that forms the top end portion T1 is formed. The cylindrical inspection hole 10 is projected upward from the top portion 2a of the. Then, concrete C is poured to a height H that is equal to or higher than the top portion 2a of the formwork 2 and equal to or lower than the upper end 10a of the cylindrical inspection hole 10. When placing the concrete C, the concrete C can be poured to a height H higher than the top portion 2a of the formwork 2, and the worker M leans upwards from the cylindrical inspection hole 10 and the top end portion. It is possible to check the pouring and placing conditions of concrete C into T1.

Therefore, it is possible to compact the concrete C having a height H higher than the top 2a of the mold 2 while visually confirming the condition of placing the concrete C to the height H higher than the top 2a of the form 2. .. Therefore, the compaction of the concrete C having a height H equal to or higher than the top portion 2a of the form 2, that is, the upper end of the inner peripheral surface T4 of the tunnel T or more is performed while visually confirming the condition to ensure the bubbles inside the concrete C. Since it can be removed, the quality of the concrete C at the top end T1 of the tunnel T can be improved.

Therefore, the defect of the concrete C at the top end T1 can be suppressed. The concrete C is cast into the top end T1 in two steps before and after closing the tubular inspection hole 10. That is, the step of placing the concrete C on the lower top portion T11 and the step of placing the concrete C on the upper top portion T12 are performed separately. Therefore, it is possible to reduce the amount of placing the concrete C on the top end T1 in each step. Therefore, the material separation of the concrete C can be suppressed more reliably, which contributes to further improvement of the quality of the concrete C at the top end T1.

Further, as shown in FIG. 2, the side wall portion T2 has a pair of side portions T21 and a pair of shoulder portions T22 located between each of the pair of side portions T21 and the top end portion T1. A side casting hole 2e is formed on the bottom surface of the mold 2 forming the portion T21, and a shoulder blow-up opening 2c is formed on the bottom surface of the mold 2 forming the shoulder portion T22. The step of placing the concrete C on each of the side wall portions T2 includes the step of placing the concrete C on each of the pair of side portions T21 from the side portion pouring port 2e, and the pair of shoulder portions T22 from each of the shoulder blowing ports 2c. Of placing concrete C on each of the above.

Therefore, after the concrete C is cast from the side casting port 2e to each of the pair of side portions T21, the concrete C is cast from each of the shoulder blow-up ports 2c to each of the pair of shoulder portions T22. Therefore, since the concrete C is cast on the side wall portion T2 in two steps, the amount of concrete C placed on the side wall portion T2 in each step can be reduced. As a result, the material separation of the concrete C can be suppressed more reliably.

In addition, in the method for placing concrete in the tunnel lining according to the present embodiment, after the step of placing the concrete C above the height H, as shown in FIG. The method includes a step of compacting the concrete C that has been cast into the concrete. In the step of compacting, the vibrator V inserted in the cast concrete C is moved in the axial direction D1 of the tunnel T while vibrating the vibrator V to compact. Harden. Therefore, after the concrete C is cast on the uppermost part of the tunnel T, the concrete C is compacted while moving the vibrator V in the axial direction D1 of the tunnel T. Therefore, by compacting while moving the vibrator V, the concrete C at the top of the tunnel T can be compacted efficiently.

Further, the method for placing concrete for tunnel lining according to the present embodiment includes a step of pulling out the tubular inspection hole 10 downward from the top 2a of the mold 2 after the step of closing the tubular inspection hole 10. Therefore, after closing the cylindrical inspection hole 10, the cylindrical inspection hole 10 can be drawn downward from the top 2a of the mold 2. Therefore, since the vibrator V does not hit the cylindrical inspection hole 10 when compacting the concrete C that is cast above the height H, the concrete C can be compacted more efficiently.

Although the embodiment of the method for placing a tunnel lining concrete according to the present invention has been described above, the present invention is not limited to the above-described embodiment, and does not change the gist described in each claim. It may be modified or applied to other things. That is, the content and order of each step of the method for placing tunnel lining concrete can be appropriately changed without changing the above-mentioned gist.

For example, in the above-described embodiment, an example has been described in which the concrete C is cast on the top T12 of the top and the tubular inspection hole 10 is pulled out downward. However, the present invention is not limited to this example. For example, when the tubular inspection hole 10 is pulled down, the concrete C may not be placed, and after the tubular inspection hole 10 is pulled down, the concrete C is placed on the top T12 of the crown. You may go.

Moreover, in the above-described embodiment, the concrete C having a slump value of about 15 cm has been described. However, the hardness and type of concrete C can be changed as appropriate. In particular, in this embodiment, since the quality of the concrete C of the top end portion T1 can be improved, it is possible to use concrete C having various hardnesses and increase the types of applicable concrete C. Therefore, for example, it is possible to make the hardness of the concrete C that is cast into the top tip T12 softer than that of the concrete C that is cast into another portion, and to cast the concrete C onto the top top T12 efficiently and accurately. Is.

Further, in the above-described embodiment, the cylindrical inspection hole 10 having the cylindrical side portion 11 has been described. However, for example, the tubular inspection hole may have a rectangular tubular shape, and the shape, size, number, material, and arrangement of the tubular inspection holes protruding upward from the mold can be appropriately changed. Also, the configuration of the lid is not limited to the configuration including the plurality of valve portions 12a, and may be, for example, a lid of an inwardly-opening door member or a door that slides and opens/closes in the circumferential direction. The configuration of the shape inspection hole can be appropriately changed.

Further, in the above-described embodiment, the example in which the vibrator V is provided at the tip of the linear member V1 has been described. However, for example, a cord extending from the reel or a vibrator attached to the tip of a steel rod may be used, and the configuration of the vibrator can be appropriately changed. Furthermore, in the above-described embodiment, the tunnel T which is a road tunnel has been described. However, the application, shape, and size of the tunnel can be appropriately changed, and the present invention can be applied to the construction of various tunnels.

DESCRIPTION OF SYMBOLS 1... Centering for lining, 2... Formwork, 2a... Top part, 2b... Inspection window, 2c... Shoulder blow-up mouth, 2d... Top end blow-up mouth, 2e... Side pouring mouth, 3... Gantry, 3a... Rail 4... Support member, 10... Cylindrical inspection hole, 10a... Upper end, 11... Side part, 12... Lid part, 12a... Valve part, 12b... Pipe insertion hole, 12c... Shaft part, 13... Seal member, 15... Lid member, C... Concrete, D1... Axial direction, D2... Circumferential direction, D3... Axial direction, D4... Circumferential direction, J... Natural ground, J1... Inner peripheral surface, K... Placing space, M... Worker, P ... pipe, T... tunnel, T1... crown part, T2... side wall part, T4... inner peripheral surface, T21... side part, T22... shoulder part, V... vibrator, V1... linear member.

Claims (4)

A method of placing concrete in a tunnel lining for constructing a tunnel having a top end and a pair of side walls located on both sides of the top end,
A step of placing concrete on each of the pair of side wall portions,
Projecting a cylindrical inspection hole upward from the top of the mold forming the top end;
A step of placing concrete to a height not lower than the top portion and not higher than the upper end of the cylindrical inspection hole protruding upward from the top portion,
After placing concrete to the height, closing the tubular inspection hole,
A step of placing concrete above the height,
A method for placing concrete in a tunnel lining. The side wall portion has a pair of side portions, and a pair of shoulder portions located between each of the pair of side portions and the top end portion,
A side casting hole is formed in the formwork forming the side portion, and a shoulder blow-up mouth is formed on the bottom surface of the formwork forming the shoulder portion,
The step of placing concrete on each of the pair of side wall portions,
A step of pouring concrete from the side pouring port to each of the pair of side parts;
Placing concrete from the shoulder blow-off mouth to each of the pair of shoulders,
The method for placing concrete for tunnel lining according to claim 1. After the step of placing the concrete above the height, a step of compacting the concrete placed above,
In the step of compacting, the vibrator inserted in the poured concrete is moved in the axial direction of the tunnel to vibrate the vibrator for compaction.
The method for placing concrete for tunnel lining according to claim 1 or 2. After the step of closing the tubular inspection hole, a step of pulling the tubular inspection hole downward from the top of the mold is provided.
The method for placing concrete for tunnel lining according to any one of claims 1 to 3.

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