JP7076363B2 - How to place tunnel lining concrete - Google Patents

Description

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

Conventionally, various methods have been known as a method for placing tunnel lining concrete. Japanese Unexamined Patent Publication No. 2008-88696 describes a method for constructing a tunnel lining. In this construction method, an arch-shaped formwork in which a plurality of work windows that can be opened and closed are formed is used. The work window is used for inspection, confirmation of concrete driving status, compaction work with a vibrator, and cleaning work of formwork.

Concrete placement is carried out from the lower side walls of the tunnel toward the upper top of the tunnel. First, concrete is placed between the formwork and the side wall, and at this time, a concrete casting pipe is inserted from the work window and concrete is placed between the formwork and the side wall from the casting pipe. In addition, a vibrator is inserted from a work window different from the work window into which the concrete placing pipe is inserted, and the placed concrete is compacted. At this time, the concrete placing situation can be visually confirmed 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 casting pipe is inserted into another working window located above (top end side) of the working window, and concrete is poured, compacted, and the casting status is confirmed in the same manner as described above. After the placement, compaction, and confirmation of the placement status of the walls on both sides of the tunnel are completed, the top of the tunnel will be placed.

The top end first blow-up port is formed on the lap side of the uppermost portion of the formwork, and the top end second blow-up port is formed on the wife side of the uppermost portion of the formwork. In the placement of the top of the tunnel, first, the casting pipe is inserted into the top end first blow-up port and concrete is placed while applying a predetermined pressure, and then the top end second blow-up is performed. Insert the casting pipe into the mouth and cast concrete while applying a predetermined pressure.

On the lap side of the top end, a vibrator attached to the tip of a rod-shaped member extending from a hoisting mechanism located on the gable side is provided. After filling the top with concrete, the vibrator is pulled from the lap side to the gable side by a hoisting mechanism to compact the concrete from the lap side to the gable side. A crown window for opening and closing the top end is provided on the top surface of the formwork. However, since this crown window is closed before the start of work, it is not possible to visually recognize the condition of concrete being placed on the top of the formwork including the top of the formwork.

Japanese Patent No. 5916353 describes a method for constructing 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, concrete is placed on a pair of side wall portions, concrete is placed on a pair of arch portions, and then concrete is placed on the top end portion. When placing concrete on the top, concrete is placed up to the window provided inside the upper part of the top, and then after closing the window, concrete is placed above the window. conduct. Since the concrete is placed on the upper part after the window is closed, it is not possible to visually recognize the concrete on the top including the top of the formwork.

Japanese Patent No. 6240478 describes a concrete placing method using a tunnel lining formwork. A plurality of blow-up casting holes are provided at the top of the tunnel lining formwork. The concrete is poured from the blown-up holes selected from the plurality of blown-up holes, and the blown-up holes are selected in a regular order. Each blow-up casting hole opens in a circular shape and is closed after filling with concrete.

Japanese Unexamined Patent Publication No. 2008-88696 Japanese Patent No. 5916353 Japanese Patent No. 6240478

In the concrete placing method described above, an opening such as an inspection window is formed on the bottom surface of the formwork constituting the top end of the tunnel, and concrete is filled through the opening. However, since the opening must be closed after the concrete is filled from the opening, it is not possible to visually recognize the concrete placing state at the top end. In addition, since the flow distance of concrete at the top of the tunnel is longer than that of other parts, it may not be possible to suppress the material separation of concrete, and there is a concern that the concrete at the top of the tunnel may malfunction. .. If the concrete at the top of the tunnel becomes defective, it may peel off. 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 tunnel lining concrete that can improve the quality of concrete at the top of a tunnel.

The method for placing tunnel lining concrete according to the present invention is a method for placing tunnel lining concrete for constructing a tunnel having a top end portion and a pair of side wall portions located on both sides of the top end portion. A step of placing concrete on each of the pair of side wall portions, a step of projecting a tubular inspection hole upward from the top of the mold forming the top end, and a step of projecting above the top and upward from the top. The process of placing concrete to a height below the upper end of the tubular inspection hole, the process of closing the tubular inspection hole after placing concrete to that height, and the process of placing concrete above the height. And, the tubular inspection hole has a tubular side portion that is movable up and down with respect to the mold.

In this tunnel lining concrete placing method, after 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 portion. 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 casting, it is possible to pour concrete to a height above the top of the formwork, and lean upward from the tubular inspection hole to check the concrete pouring and casting status to the top. It is possible to do. Therefore, it is possible to confirm the concrete placement status at the top end. Further, the concrete can be compacted at a height higher than the top of the formwork while visually confirming the state of placing the concrete at a height higher than the top of the formwork. Therefore, it is possible to reliably remove air bubbles inside the concrete by visually checking the compaction of the concrete at a height above the top of the formwork, that is, above the upper end of the inner peripheral surface of the tunnel. The quality of the concrete of the part can be improved. Therefore, it is possible to suppress defects in the concrete at the top end. Further, since the concrete is placed on the top end in two steps before and after the tubular inspection hole is closed, the amount of concrete placed on 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.

Further, 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, and the side portion casting port is provided in the formwork forming the side portion. Is formed, and a shoulder blow-up opening is formed on the bottom surface of the formwork forming the shoulder portion, and the step of placing concrete on each of the pair of side wall portions is a pair from the side placement opening. 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 casting port to each of the pair of side portions, and then concrete is poured from the shoulder blowing port to each of the pair of shoulder portions. Therefore, since the concrete is placed on the side wall portion in two steps, the amount of concrete placed on the side wall portion in each step can be reduced. As a result, the material separation of concrete can be suppressed more reliably.

Further, the above-mentioned tunnel lining concrete placing method includes a step of placing concrete above the height and then a step of compacting the concrete placed above, and in the compacting step, the step of placing concrete is provided. You may perform compaction by vibrating the vibrator while moving the vibrator inserted in the 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, it is possible to efficiently compact the concrete at the top of the tunnel.

Further, the above-mentioned method of placing lining concrete may include a step of pulling out the cylindrical inspection hole downward from the top of the formwork after the step of closing the tubular inspection hole. In this case, after closing the tubular inspection hole, the tubular inspection hole can be pulled downward from the top of the mold. Therefore, since the vibrator does not hit the cylindrical inspection hole in the compaction of the concrete poured above the height, the compaction of the concrete can be performed more efficiently.

According to the present invention, the quality of the concrete at the top of the tunnel can be improved.

It is a perspective view schematically showing the tunnel constructed by the tunnel lining concrete placing method 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 upward from the formwork used in the tunnel lining concrete placing method which concerns on embodiment. It is a vertical sectional view of the cylindrical inspection hole of FIG. It is sectional drawing which shows the outline of the method of placing the tunnel lining concrete which concerns on embodiment. FIG. 3 is a perspective view showing an example of a state in which concrete is placed and compacted on the shoulder of the tunnel of FIG. 1. (A), (b), (c), (d) and (e) are procedures for projecting a cylindrical inspection hole to the top of the tunnel of FIG. 1 and placing concrete on the top. It is a plan view and a vertical sectional view of a cylindrical inspection hole which shows. It is a side view of the tunnel which shows the state which pulled out the cylindrical inspection hole downward from the top end part. It is a side view which shows typically the state which performs the compaction of the concrete of a crown part.

Hereinafter, an embodiment of a method for placing tunnel lining concrete according to the present invention will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and duplicate description will be omitted as appropriate. In addition, the drawings may be partially simplified or exaggerated for the sake of easy understanding, and the dimensional ratios and the like are not limited to those described in the drawings.

In the construction of the tunnel T according to the present embodiment, for example, after excavating the ground J (see FIG. 5) and spraying mortar (shotcrete) on the inner peripheral surface J1 which is the excavated surface, the lining center 1 is used. Install and drive concrete C. 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 the concrete C according to the present embodiment. As shown in FIG. 1, the lining center 1 is used when concrete C is placed on the inner peripheral surface J1 of the ground J where the concrete spraying is completed.

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 ground J and the formwork 2. Concrete C is placed in the building. After placing the concrete C, the concrete C is protected (cured) by maintaining the state for a predetermined time.

The lining center 1 further includes a gantry 3 that supports the formwork 2 from the inside (center side) of the tunnel T, and the gantry 3 is capable of being combined with and separated from the formwork 2. The formwork 2 is formed in an inverted U shape (horseshoe shape) and is open downward. The gantry 3 is a gate-shaped mobile 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 support 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 form 2.

As shown in FIGS. 1 and 2, the concrete C of the tunnel T constitutes the top end portion T1 and the side wall portion T2 of the tunnel T, and the side wall portion T2 includes the side portion T21 and the shoulder portion T22 of the tunnel T. Includes. In the method of placing the lining concrete according to the present embodiment, after the concrete C is placed on the side portion T21 and the concrete is placed on the shoulder portion T22, the concrete C is placed on the top end portion T1. The setting is divided into two steps. The crown T1 has a top bottom T11 including the upper end of the inner peripheral surface T4 of the tunnel T, and a top top T12 located above the top of the top bottom T11 and including the top of the tunnel T.

The formwork 2 has a plurality of tubular inspection holes 10 protruding upward from the top 2a, and the concrete C is placed in the top end T1 using the tubular inspection holes 10. The tubular inspection hole 10 is a tubular extension-type inspection window that allows the worker M to lean upward and visually check the concrete C at the top end T1, and is movable up and down. For example, the operator M leans out from the cylindrical inspection hole 10 and moves the vibrator V attached to the tip of the linear member V1 while vibrating inside the concrete C to compact the concrete C. ..

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-up openings 2c facing the shoulder portion T22 of the tunnel T, and the sky of the tunnel T. It is provided with a plurality of top blowing-up ports 2d facing the end portion T1 and a side casting port 2e facing the side portion T21 of the tunnel T. The inspection window 2b, the shoulder blowing port 2c, the top blowing opening 2d, and the side casting port 2e are all rectangular, for example. Further, a pipe is ejected from the shoulder blowing port 2c, the top blowing port 2d, and the side casting port 2e into the casting space K of the concrete C, and the concrete C flows from this pipe into the casting space K. The plurality of shoulder blowing openings 2c, the plurality of top blowing openings 2d, and the plurality of side casting openings 2e are arranged so that the flow distance of the concrete C is, for example, 2 m or less.

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. Perform consolidation.

Each of the shoulder blow-up port 2c and the side casting port 2e is arranged, for example, at a position adjacent to the inspection window 2b. A pipe for supplying concrete C is ejected from each of the shoulder blow-up port 2c and the side casting port 2e, and the concrete C is cast from the pipe to the side wall portion T2. A plurality of shoulder blow-up openings 2c and a plurality of side casting openings 2e are arranged so as to be lined up along the axial direction D1. For example, each of the shoulder blow-up port 2c and the side casting port 2e is arranged at an position adjacent to the even-numbered inspection window 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 casting port 2e can be changed as appropriate.

The top blowing port 2d is arranged, for example, at a position adjacent to the tubular inspection hole 10. Similar to the above, a pipe is taken out from the top end blowing port 2d, and concrete C is placed from the pipe to the top end lower portion T11 of the top end portion T1. A plurality of top blowing ports 2d are arranged so as to be lined up along the axial direction D1. For example, the top blowing port 2d is not arranged at a position adjacent to all the tubular inspection holes 10. As an example, the tubular inspection holes 10 in which the top blowing port 2d is arranged and the tubular inspection holes 10 in which the top blowing port 2d is not arranged may be alternately arranged along the axial direction D1. In this way, the number, shape, and arrangement position of the top blowing port 2d can be changed as appropriate.

FIG. 3 is a simplified perspective view showing an exemplary cylindrical inspection hole 10. FIG. 4 is a simplified vertical sectional view showing an exemplary cylindrical inspection hole 10. As shown in FIGS. 3 and 4, the tubular inspection hole 10 is located, for example, in a tubular side portion 11 that can be moved up and down with respect to the mold 2 and an upper portion of the side portion 11. A lid portion 12 that can open and close the tubular inspection hole 10, a seal member 13 that surrounds the side portion 11 and is interposed between the side portion 11 and the formwork 2, and the side portion 11 up and down with respect to the formwork 2. It is equipped with a slide mechanism (not shown) that slides.

The tubular inspection hole 10 is, for example, an upper lid type in which a lid portion 12 is provided on the 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 can swing 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, an elastic material. The valve portion 12a is swingable in the axial direction D3 about the shaft portion 12c extending along the circumferential direction D4 of the side portion 11 at the upper portion of the side portion 11.

In a state where the tubular inspection hole 10 is closed, the plurality of valve portions 12a are in close contact with each other along the mold 2 (a plane orthogonal to the axial direction D3). The pipe insertion hole 12b is provided in the center of the lid portion 12 in a plan view. With the tubular inspection hole 10 closed, the pipe P (see FIG. 7) can be inserted into the pipe insertion hole 12b along the axial direction D3. This makes it possible to cast 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, and can be appropriately changed.

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

First, as shown in FIG. 6, concrete C is placed on each of the pair of side portions T21 (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 openings 2e (see FIG. 2), and the concrete C is poured 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 from the inspection window 2b, and vibrates the concrete C of the side portion T21 with the vibrator V to compact the concrete C.

Next, concrete C is placed on each of the pair of shoulder portions T22 (a step of placing concrete on each of the pair of shoulder portions). For example, concrete C is poured from each of the plurality of shoulder blow-up ports 2c into the casting space K to blow-up the concrete C onto the shoulder portion T22, and the concrete C of the shoulder portion T22 is vibrated by the vibrator V in the same manner as described above. Let it compact the concrete C.

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 portion T11, and the tubular inspection is projected upward from the top 2a and above and from the top 2a. Concrete C is placed up to a height H of 10 a or less at the upper end of the hole 10 (a step of projecting the cylindrical inspection hole, a step of placing concrete to a height of less than the upper end of the tubular inspection hole). That is, concrete C is placed on the lower top end T11.

As a specific example, as shown in FIGS. 5 and 7A, the tubular inspection hole 10 is opened in a state where each of the plurality of valve portions 12a is swung downward to open the tubular inspection hole 10. Concrete C is placed around the cylindrical inspection hole 10 from the top blowing-up port 2d so as to project upward from the mold 2. At this time, the concrete C is injected from the pipe P into the casting space K through the pipe P from the top blowing-up port 2d into the casting space K, and the concrete C is poured until the concrete C reaches the height H. At this time, the worker M leans out from the tubular inspection hole 10 to compact the concrete C with the vibrator V and confirms the casting status of the concrete C, whereby the upper end of the inner peripheral surface T4 of the tunnel T is confirmed. The quality of the concrete C of the lower end T11 including the above is ensured.

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

Subsequently, as shown in FIGS. 7 (d), 7 (e) and 8, the drawing of the tubular inspection hole 10 downward of the mold 2 is continued, and the upper end 10a of the tubular inspection hole 10 is formed. After lowering to the height of the form 2, the pipe P is pulled downward 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 placed above the height H (upper top T12) is compacted (the step of compacting the concrete placed 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 axial direction D1 of the concrete C. After that, the linear member V1 is moved to the other end side of the axial direction D1 while vibrating the concrete C with the vibrator V, and the concrete C is compacted while the vibrator V is gradually moved to the other end side of the axial direction D1. .. As described above, after the concrete C of the upper end T12 is compacted, the concrete C is hardened and cured to complete a series of steps.

Next, the operation and effect of the tunnel lining concrete placing method 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, the formwork 2 that forms the top end portion T1 after placing the concrete C on each of the pair of side wall portions T2. A tubular inspection hole 10 is projected upward from the top portion 2a of the concrete. Then, the concrete C is placed up to a height H of the top 2a or more of the form 2 and the upper end 10a or less of the tubular inspection hole 10. In the casting of the concrete C, the concrete C can be poured up to a height H of the top 2a or more of the formwork 2, and the worker M leans upward from the tubular inspection hole 10 to the top end portion. It is possible to confirm the pouring and casting status of the concrete C into T1.

Therefore, it is possible to compact the concrete C having a height H of the top 2a or more of the formwork 2 while visually confirming the casting condition of the concrete C on the height H of the top 2a or more of the formwork 2. .. Therefore, the concrete C having a height H equal to or higher than the top 2a of the formwork 2, that is, the upper end of the inner peripheral surface T4 of the tunnel T or higher is compacted while visually checking the situation to ensure that air bubbles inside the concrete C are removed. Since it can be removed, the quality of the concrete C at the top end portion T1 of the tunnel T can be improved.

Therefore, it is possible to suppress the defect of the concrete C of the top end portion T1. Further, the placing of the concrete C on the top end portion T1 is performed 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 T11 and the step of placing the concrete C on the upper top T12 are performed separately. Therefore, it is possible to reduce the amount of concrete C placed on the top end portion 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 portion 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 port 2e is formed on the bottom surface of the formwork 2 forming the portion T21, and a shoulder blow-up port 2c is formed on the bottom surface of the formwork 2 forming the shoulder portion T22. The steps of placing concrete C in each of the side wall portions T2 include a step of placing concrete C in each of the pair of side portions T21 from the side placing port 2e and a pair of shoulder portions T22 from the shoulder blowing port 2c. It includes a process of placing concrete C in each of the above.

Therefore, after the concrete C is placed in each of the pair of side portions T21 from the side placing port 2e, the concrete C is placed in each of the pair of shoulder portions T22 from the shoulder blowing port 2c. Therefore, since the concrete C is placed on the side wall portion T2 in two steps, the amount of the 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.

Further, in the method of placing the tunnel lining concrete according to the present embodiment, after the step of placing the concrete C above the height H, as shown in FIG. 9, the upper part (upper top T12). In the step of compacting the concrete C placed in the concrete C, the vibrator V inserted in the placed concrete C is vibrated and compacted while being moved in the axial direction D1 of the tunnel T. Perform consolidation. Therefore, after the concrete C is placed on the uppermost portion of the tunnel T, the concrete C is compacted while the vibrator V is moved in the axial direction D1 of the tunnel T. Therefore, by performing compaction while moving the vibrator V, compaction of the concrete C at the uppermost portion of the tunnel T can be efficiently performed.

Further, the method of placing the tunnel lining concrete according to the present embodiment includes a step of pulling out the tubular inspection hole 10 downward from the top 2a of the formwork 2 after the step of closing the tubular inspection hole 10. Therefore, after closing the tubular inspection hole 10, the tubular inspection hole 10 can be pulled downward from the top 2a of the mold 2. Therefore, since the vibrator V does not hit the tubular inspection hole 10 in the compaction of the concrete C placed above the height H, the compaction of the concrete C can be performed more efficiently.

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

For example, in the above-described embodiment, an example in which the concrete C is placed in the upper portion T12 of the top end and the concrete C is pulled out downward of the cylindrical inspection hole 10 has been described. However, the present invention is not limited to this example, and for example, when the tubular inspection hole 10 is pulled down, the concrete C does not have to be placed, and after the tubular inspection hole 10 is pulled down, the concrete C is placed in the top end upper part T12. May be done.

Further, 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 the present embodiment, since the quality of the concrete C at the top end portion T1 can be improved, concrete C having various hardnesses can be used, and the types of concrete C that can be applied can be increased. Therefore, for example, it is possible to make the hardness of the concrete C to be driven into the top end upper part T12 softer than that of the concrete C to be driven into another part, and to efficiently and accurately place the concrete C into the top end upper part T12. Is.

Further, in the above-described embodiment, the tubular inspection hole 10 having the cylindrical side portion 11 has been described. However, for example, the tubular inspection hole may be a square cylinder, and the shape, size, number, material, and arrangement of the tubular inspection hole protruding upward from the mold can be appropriately changed. Further, the structure of the lid portion is not limited to the configuration including a plurality of valve portions 12a, and may be, for example, a lid portion of a door member that opens inward, a door portion that slides in the circumferential direction to open and close, and the like. The configuration of the condition inspection hole can be changed as appropriate.

Further, in the above-described embodiment, an 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 a 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. Further, in the above-described embodiment, the tunnel T, which is a road tunnel, has been described. However, the use, shape and size of the tunnel can be changed as appropriate, and the present invention can be applied to the construction of various tunnels.

1 ... lining center, 2 ... formwork, 2a ... top, 2b ... inspection window, 2c ... shoulder blow-up port, 2d ... top-end blow-up port, 2e ... side casting port, 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 ... Cover member, C ... concrete, D1 ... axial direction, D2 ... circumferential direction, D3 ... axial direction, D4 ... circumferential direction, J ... ground, J1 ... inner peripheral surface, K ... casting space, M ... worker, P ... Pipe, T ... Tunnel, T1 ... Top end, T2 ... Side wall, T4 ... Inner peripheral surface, T21 ... Side, T22 ... Shoulder, V ... Vibrator, V1 ... Linear member.

Claims (4)

It is a method of placing tunnel lining concrete for constructing a tunnel having a top portion and a pair of side wall portions located on both sides of the top end portion.
The process 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 of placing concrete to a height above the top and below the upper end of the tubular inspection hole protruding upward from the top.
The process of closing the cylindrical inspection hole after placing concrete to the height, and
The process of placing concrete above the height and
Equipped with
The tubular inspection hole has a cylindrical side portion that can be moved up and down with respect to the mold.
How to place tunnel lining concrete. 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 port is formed in the formwork forming the side portion, and a shoulder blow-up opening is formed in the bottom surface of the formwork forming the shoulder portion.
The step of placing concrete on each of the pair of side wall portions is
The process of placing concrete from the side casting port to each of the pair of side portions,
A step of placing concrete from the shoulder blow-up port to each of the pair of shoulders, and the like.
The method for placing tunnel lining concrete according to claim 1. A step of compacting the concrete poured above the height is provided after the step of placing the concrete above the height.
In the compaction step, the vibrator inserted in the cast concrete is moved in the axial direction of the tunnel, and the vibrator is vibrated for compaction.
The method for placing tunnel lining concrete according to claim 1 or 2. A step of pulling out the tubular inspection hole downward from the top of the mold is provided after the step of closing the tubular inspection hole.
The method for placing tunnel lining concrete according to any one of claims 1 to 3.

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