JP2006159520A - Combined segment and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To fill the gap remaining between the inner surface of an outer shell body constituted of an arcuate sheet frame body and a form and concrete, both of which form a combined segment. <P>SOLUTION: The outer shell body R is formed by providing a form plate 16a which closes the open surface 15 opposed to the skin plate 3 on the outer peripheral side of the arcuate sheet frame body 2. A filling port 17, which is provided to the skin plate 3 for primary filling, and the filling pipe 4, which is arranged from the outer shell body R toward the gap 5 for the purpose of secondary filling, are provided to the outer shell body R. Subsequently, the outer shell body R is filled with concrete C primarily and the gap 5 where bubbles remain between the inner surface of the outer shell body R and the primarily filled concrete C is filled with a filler 6 secondarily. An air hole P which can vent the bubbles of the gap 5 to the outside of the outer shell body R is provided to the skin plate 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a synthetic segment manufacturing method and a synthetic segment formed by placing concrete inside a steel arcuate plate frame.

Conventionally, three types of segments are known as segments used in the shield method, for example, a concrete segment, a steel (steel) segment, and a composite segment using a combination of steel (steel) and concrete. Among these segments, the synthetic segment is generally manufactured by filling concrete in a steel circular plate frame.
A pair of main girder plates are fixed by welding or the like to both side edges forming the long side of the outer peripheral side steel plate of the arc plate frame, and a pair of joint plates are fixed to both side edges forming the short side by welding or the like. Has been. And the inner peripheral side which opposes an outer peripheral side steel plate is opening, and at the time of concrete pouring, a formwork board is installed in this opening and the outer shell body is formed.
As a concrete placing method in such a synthetic segment manufacturing method, there are the following methods. There are three methods for placing, depending on how the arcuate plate frame is placed and how concrete is filled.
The first is a so-called hill driving, which is arranged with the outer peripheral side steel plate on the upper side and the opening side on the lower side, and by supplying the concrete before solidification from the highest supply port of the outer peripheral side steel plate, Fill the inside of the frame. The second type is so-called boat driving, which is arranged with the outer peripheral steel plate on the lower side and the opening side on the upper side. Concrete is filled and poured into the arc plate-like frame body from a supply port provided at one end or the lowest bottom of the mold plate (see Patent Document 1). The third type is so-called vertical driving, in which the main girder plate of the arc plate-like frame body is arranged with the vertical direction, and concrete is filled into the arc plate-like frame body from the supply port provided in the upper main girder plate (patent) Reference 2).
In these placing methods, there are fine air bubbles particles in the fluid concrete filled in the arc plate frame, and these fine air bubbles improve the fluidity of the concrete before solidification. Therefore, the concrete filling efficiency is good.
JP 2001-58308 A JP 2001-105417 A

However, in the first, second, and third concrete placing methods described above, the concrete immediately below the concrete supply port swells in a mountain shape, and the supply port is blocked before the concrete is completely filled in the outer shell. End up. For this reason, the fine bubbles dispersed and mixed in the concrete rise to the upper part and the corner part in the arc-shaped plate-like frame body. However, since there is no passage, there remains a problem that a void is formed.
In the case of the first hill driving, since the arc of the outer peripheral surface of the outer shell body has a gentle inclination, a void is formed on the entire inner surface of the outer peripheral surface. And, in the case of the second piercing, for example, since both ends forming the short side of the arcuate plate frame are higher than the concrete supply port, air bubbles are accumulated at the corners of both ends to form a gap. . In the case of the third vertical striking, the upper main girder plate is substantially flat, so that air bubbles remain in the vicinity of the corner opposite to the supply port of the main girder plate to form a gap. The
These voids formed by the respective placement methods of the synthetic segment become unfilled portions of the concrete, and there is a drawback that the strength of the synthetic segment is lowered and the life is shortened.
Further, although the voids appearing on the surface of the synthetic segment after demolding can be repaired, there is a problem that the repair work is troublesome and the cost of the repair material is also increased.

  The present invention has been made in view of the above-described problems, and fills a gap remaining between the inner surface of the outer shell body formed of the arcuate plate frame and the mold plate forming the composite segment and the concrete. It is an object of the present invention to provide a synthetic segment manufacturing method and a synthetic segment.

In order to achieve the above object, a synthetic segment manufacturing method according to the present invention is a synthetic segment manufacturing method in which concrete is cast in a steel arc plate-like frame body. A form plate that closes the opening is attached to form an outer shell body, and then the concrete is primarily filled into the outer shell body, and then, in the gap where air bubbles remain between the inner surface of the outer shell body and the primary filled concrete, It is characterized in that the gap is filled by secondary filling of concrete through the arranged filling pipe.
According to the present invention, since concrete is secondarily filled through a pre-arranged filling pipe in a gap formed by rising fine bubbles dispersed and mixed in the primary filled concrete, the concrete is not filled. The place disappears. By this manufacturing process, a high-strength synthetic segment can be manufactured. In addition, since the filling tube is provided in the outer shell before the primary filling, it is not necessary to set up the secondary filling after the primary filling, and the operation can be simplified.

Further, according to the synthetic segment manufacturing method of the present invention, when the concrete is secondarily filled into the space using the filling tube, the passage through which the remaining bubbles escape to the outside of the outer shell body is provided. It is preferable to be provided in the area.
According to the present invention, the passage provided in the outer shell body functions as an air vent, and the air bubbles formed during the primary filling can be surely removed outward from the outer shell body. Can be improved.

Further, according to the synthetic segment manufacturing method of the present invention, in the synthetic segment manufacturing method formed by placing concrete in the steel arc plate frame, the opening of the arc plate frame is closed. A form plate is attached to form an outer shell, and then the concrete is primarily filled into the outer shell, and then the voids between the inner surface of the outer shell and the primary filled concrete are left in the outer shell. A feature is that a through hole is formed to communicate with the outside, and concrete is secondarily filled from the through hole to fill the gap.
According to the present invention, no special material is required, and it becomes a simple operation by providing a through hole at a position where the formation of the void of the outer shell body is expected after the primary filling of the concrete, and the work time after the primary filling is reduced. Can be shortened. The concrete can be filled into the voids by secondary filling, and a high quality synthetic segment can be obtained.

The synthetic segment according to the present invention is a synthetic segment formed by placing concrete inside a steel arcuate plate frame, in which bubbles between the inner surface of the arcuate plate frame and the primary filled concrete remain. It is characterized in that a filling pipe for secondary filling of concrete from the outside is provided in the gap.
In the present invention, since the concrete is filled through the filling pipe into the gap where the air bubbles remain between the inner surface of the outer shell and the primary filled concrete, a high strength composite segment can be secured.

According to the synthetic segment manufacturing method of the present invention, by providing a filling tube in the outer shell in advance, there is no need for a setup operation for secondary filling after the primary filling, so that the working efficiency is good. In addition, since the concrete can be secondarily filled in the gap remaining between the inner surface of the outer shell and the primary filled concrete, a high-strength synthetic segment without unfilled portions of the concrete can be manufactured.
According to the method for manufacturing a synthetic segment in which a through-hole is provided in the outer shell of the present invention, secondary filling can be performed by a simple operation without using a special material after one filling, and an unfilled portion of concrete can be obtained. High quality synthetic segments can be produced.
Moreover, according to the synthetic segment by this invention, since the concrete is inject | poured into the formed space | gap, high quality can be ensured. Moreover, the secondary filling operation can be simplified by preparing the filling tube in the outer shell before placing the concrete.

The synthetic segment manufacturing method and synthetic segment according to the first embodiment of the present invention will be described below with reference to FIGS.
1 is a perspective view of a composite segment according to the first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA of the composite segment shown in FIG. 1, and FIG. 3 is an arc plate-like frame in the composite segment shown in FIG. FIG. 4 is a longitudinal sectional view showing a state in which concrete is placed in the synthetic segment manufacturing process according to the first embodiment, and FIG. 5 is a sectional view taken along the line BB of the synthetic segment shown in FIG. is there.
As shown in FIG. 1, the composite segment 1 obtained by the manufacturing method according to the first embodiment is an arc formed from steel materials covering the four corners of the outer peripheral surface on the natural ground side and the inner peripheral surface on the inner air side. A plate-like frame 2; a skin plate 3 that is curved and welded to the outer circumferential surface of the arc-shaped plate-like frame 2 in a cylindrical circumferential shape; and a concrete C that is placed inside the arc-shaped plate-like frame 2; It is roughly composed.

  As shown in FIG. 2, the arcuate plate-like frame body 2 is provided with a filling tube 4 from the substantially middle in the thickness direction in the long side direction toward the inner surface of the skin plate 3. An appropriate number of filling tubes 4 are provided in the longitudinal direction of the arcuate plate frame 2. The end portion 4 a that forms the filling outlet of the filling tube 4 is disposed slightly away from the inner surface of the skin plate 3 in the inward direction.

  In addition, as shown in FIG. 2, inside the arcuate plate frame 2, fine bubbles dispersed and mixed in the primary filling concrete C rise and gather on the inner surface of the skin plate 3, thereby forming a gap. 5 is formed. The end 4a of the filling tube 4 is provided in a region where the formation of the gap 5 is expected, and the other end opens to the outside. The void 5 formed after the primary filling is secondarily filled with concrete as the filler 6. A filling material 6 is filled in the filling tube 4 after the secondary filling.

The arcuate plate frame 2 of the composite segment 1 has the configuration shown in FIGS. That is, the arcuate plate-shaped frame 2 is formed in a quadrangular frame shape curved on an arc on the outer peripheral surface side and has a substantially L-shaped cross section, and is curved on the arc on the inner peripheral surface side. And a second structural member 8 having a substantially rectangular frame shape and a substantially L-shaped cross section.
The first structural member 7 includes plate portions 7a and 7a that extend along the outer peripheral surface in the longitudinal direction, plate portions 7b and 7b that extend along the thickness direction in the longitudinal direction, and a thickness direction in the short side direction. The plate parts 7d and 7d extending along the line are formed. And about the 2nd structural member 8, similarly to the 1st structural member 7, plate part 8a, 8a, 8b, 8b and 8d, 8d are formed.
The first structural member 7 and the second structural member 8 are connected by a connecting member 9. The connecting member 9 has a lattice structure in which a plurality of steel materials are arranged in a substantially V shape. Furthermore, an opening 10 is formed between the plate portions 7b and 8b in the longitudinal direction of the arcuate plate frame 2, and an opening 11 is formed between the plate portions 7d and 8d in the short side direction. Has been.
Further, a seal groove 12 is formed around each of the first structural member 7 and the second structural member 8, and a sealing material 12 a is provided in the seal groove 12. Further, an inter-segment joint 13 for connecting circumferential segments and an inter-ring joint 14 for connecting segments between rings are provided (see FIG. 1).

The configuration of the composite segment 1 according to the present embodiment is as described above, and the manufacturing method thereof will be described with reference to FIGS.
The synthetic segment 1 shown in FIG. 4 shows a manufacturing process by a so-called mountain driving method. In this manufacturing process, the inter-segment joint 13 and the inter-ring joint 14 are attached to the arc-shaped plate frame 2 in advance, the skin plate 3 on the outer peripheral side of the arc-shaped plate-shaped frame 2 is set on the upper side, and the inner peripheral side thereof The outer shell R is formed by being placed on the mold plate 16 with the opening surface 15 forming the lower side facing down. The mold plate 16 includes a mold plate 16a provided by closing the opening 15 so as to form an inner peripheral surface of the composite segment 1 in an arc shape, and an opening formed on the side surface of the outer shell R. 10 and 11 and a form plate 16b for closing.

The skin plate 3 is provided with a filling port 17 for filling and injecting (primary filling) concrete C substantially at the center at the highest position.
From the filling port 17, the concrete C before fluidization is poured into the outer shell R to be primarily filled. Due to this primary filling, the bubbles contained in the concrete C filled in the outer shell R rise toward the inner surface of the skin plate 3. Then, the injected concrete C gradually rises in a mountain shape immediately below the filling port 17 and fills up to the point where the filling port 17 is blocked, the bubbles disappear inside the skin plate 3 and remain inside the skin plate 3. Form.

The filling tube 4 is provided in the outer shell R in advance before the concrete C is primarily filled, and the end 4a of the filling outlet is disposed at a position where the formation of the gap 5 is expected (see FIG. 5). An injection hole 18 is formed through the mold plate 16b so as to coincide with the filling inlet of the filling tube 4. Further, the skin plate 3 is provided with an appropriate number of air holes P (passages) penetrating the inside and outside of the outer shell R in the vicinity of the end portion 4a of the filling tube 4.
Then, the filling material 6 is secondarily filled from the injection hole 18 through the filling tube 4 to be filled. At this time, the bubbles in the gap 5 pass through the air holes P and completely escape to the outside of the outer shell R. After the completion of the secondary filling, the filler 6 is poured into the filling tube 4 to close it, and the air holes P are filled with welding means or the like.

  According to the method for manufacturing the synthetic segment according to the first embodiment, the void 5 in which air bubbles remain between the inner surface of the outer shell R and the concrete C is filled by the primary filling and the secondary filling, and Thus, it is possible to manufacture a synthetic segment that ensures high quality with no unfilled portions. Since the filling tube 4 is provided in advance, the setup work for the secondary filling is not necessary after the primary filling, and the work can be simplified. Furthermore, it is not necessary to repair the void 5 after demolding, and the cost for the repair material can be reduced.

Next, a first modification of the first embodiment will be described with reference to FIG.
FIG. 6 is a diagram showing a state in which concrete is primarily filled in the synthetic segment manufacturing process.
The manufacturing method of the synthetic segment 1 shown in FIG. 6 is a concrete placement method by so-called mountain placing, with the skin plate 3 facing up and one end of the short side of the arcuate plate frame 2 being lifted to the highest position. The outer shell R is formed on the mold plate 19. The mold plate 19 includes a mold plate 19 a that closes the inner peripheral surface of the arcuate plate-like frame body 2, and a mold plate 19 b that closes the side surface thereof. A filling port 20 for pouring and filling concrete C (primary filling) is provided at the highest position of the outer shell R. Furthermore, a filling tube 4 is provided from the opening 11 on the filling port 20 side toward the inner surface of the skin plate 3 near the filling port 20. The end 4a that forms the filling outlet of the filling tube 4 is provided in a region where the gap 5 is expected to remain, and is disposed slightly away from the inner surface near the filling port 20 in the inner direction. The mold plate 19b on the filling port 20 side is provided with an injection hole 18 that coincides with the filling inlet of the filling tube 4.

  Next, as shown in FIG. 6, when the concrete C is primarily filled into the outer shell R from the filling port 20, the bubbles contained in the concrete C become the highest position in the outer shell R. It rises toward the inner surface of 20. At this time, the filling port 20 fills the concrete C and at the same time plays a role of venting air bubbles. However, at the end of the primary filling, all of the bubbles do not escape from the filling port 20 and the gap 5 is formed. Therefore, in the synthetic segment manufacturing method according to the first modification, the gap 5 is left without being completely filled first, and the filler 6 is secondarily filled into the gap 5 by the filling tube 4.

  The synthetic segment manufacturing method according to the first modification shown in FIG. 6 can achieve the same effects as those of the manufacturing method shown in FIGS. And in this modification, a filling state can be made better by leaving the space | gap 5 at the time of primary filling, and performing secondary filling. Therefore, the high quality synthetic segment 1 in which the gap 5 is reliably filled can be manufactured.

Next, a second modification will be described based on FIG.
FIG. 7 is a view showing a modified example of secondary filling in the synthetic segment manufacturing method.
The second modification is a method of performing secondary filling without providing the filling pipe 4 shown in FIGS. 4 and 5, and the configuration of the outer shell R and the remaining state of the gap 5 are the same as those in FIGS. 4 and 5. Therefore, the description is omitted.
As shown in FIG. 7, in the secondary filling method according to the second modification, through holes 21 are formed in the skin plate 3 above the outer shell R where the formation of the gap 5 is expected after the primary filling. The filler 5 is secondarily filled into the gap 5. The through hole 21 is filled with welding means or the like after the completion of the secondary filling.
In the second modification, by performing a simple operation after the primary filling, it is possible to obtain the same effect as the synthetic segment manufacturing method shown in FIGS.

Next, the manufacturing method of the synthetic segment by 2nd embodiment is demonstrated based on FIG.8 and FIG.9.
FIG. 8 is a longitudinal sectional view showing a state of primary filling in the synthetic segment manufacturing process according to the second embodiment, and FIG. 9 is a sectional view taken along the line DD of the synthetic segment shown in FIG.
The manufacturing method of the synthetic segment 1 shown in FIGS. 8 and 9 is a so-called concrete placing method by boating, and the configuration of the synthetic segment 1 is the same as that of the first embodiment. Therefore, the second embodiment will be described below with a focus on differences from the first embodiment.
As shown in FIG. 8, in the manufacturing method according to the second embodiment, the arcuate plate frame 2 is horizontally placed with the inner peripheral opening surface 15 on the upper side and the outer skin plate 3 on the lower side. It has been placed. The opening surface 15 is provided with a mold plate 22a having a shape along the inner peripheral surface of the arcuate plate frame 2 and a mold plate 22b for closing the side surface of the arc plate frame 2. The body R is formed. A filling port 23 for pouring and filling concrete C (primary filling) is provided therethrough at a position at the lowest position in the approximate center of the mold plate 22a.
Further, a filling tube 4 is provided from the opening 10 on the side surface of the outer shell R toward the inner surface of the mold plate 22a. The end 4a that forms the filling outlet of the filling tube 4 is provided in a region where the gap 5 is expected to remain, and is disposed slightly away from the inner surface of the mold plate 22a inward (FIG. 9). reference).
An injection hole 18 is provided through the mold plate 22b so as to coincide with the filling inlet of the filling tube 4. Further, as shown in FIG. 9, the mold plate 22a has air holes P (passages) penetrating in the vicinity of the end 4a of the filling tube 4 so as to connect the inside and outside of the outer shell R appropriately. Numbers are provided.

Next, as shown in FIG. 8, the bubbles contained in the concrete C filled in the outer shell R by the primary filling rise toward the inner surface of the mold plate 22a. Then, the concrete C gradually rises in a mountain shape immediately below the filling port 23, and when filled up to the point where the filling port 23 is blocked, the bubbles do not escape and remain inside the outer shell R to form the void 5. To do.
In the second embodiment, since the filling port 23 is at the lowest position of the mold plate 22a, the gap 5 is also formed at both corners of the short side of the upper part of the outer shell R. Then, the filler 6 is secondarily filled into the gap 5 from the injection hole 18 through the filling tube 4. At this time, the bubbles in the gap 5 pass through the air holes P and completely escape to the outside of the outer shell R. After the completion of filling, the filling material 6 is poured into the filling tube 4 and closed.

  As described above, in the synthetic segment manufacturing method according to the second embodiment, the same effects as in the first embodiment can be obtained, and the high-quality synthetic segment 1 in which the gaps 5 are filled can be manufactured. .

Next, a synthetic segment manufacturing method according to the third embodiment will be described with reference to FIGS.
FIG. 10 is a perspective view showing a state in which concrete is primarily filled in the synthetic segment manufacturing process according to the third embodiment, and FIG. 11 is a central longitudinal section showing a state in which concrete is primarily filled in the synthetic segment manufacturing process shown in FIG. FIG.
The manufacturing method of the synthetic segment 1 shown in FIGS. 10 and 11 is a so-called vertical concrete placing method, and the composition of the synthetic segment 1 is the same as in the first and second embodiments. Therefore, the third embodiment will be described below with a focus on differences from the first and second embodiments.
As shown in FIG. 10, in the manufacturing method according to the third embodiment, the arcuate plate frame 2 has an arcuate plate with the opening surface 15 on the inner peripheral side and the skin plate 3 on the outer peripheral side facing in the lateral direction. The opening 10 forming the side surface in the longitudinal direction of the frame 2 is placed in the vertical direction. The arcuate plate frame 2 is provided with a mold plate 24a having a shape along the inner peripheral surface and a mold plate 24b for closing the openings 10 and 11 on the side surface of the arcuate plate frame 2. A shell R is formed. A filling port 25 for pouring and filling concrete C (primary filling) is provided in the upper mold plate 24b.
Furthermore, a filling tube 4 is provided from the skin plate 3 toward the inner surface of the upper formwork plate 24b. The end 4a that forms the filling outlet of the filling tube 4 is provided in a region where the gap 5 is expected to remain, and is disposed slightly away from the inner surface of the mold plate 24b inward (FIG. 11). reference).
As shown in FIG. 11, in the third embodiment, air bubbles remain in the vicinity of the corner opposite to the filling port 25 by the primary filling of the concrete to form the gap 5. Then, the filling material 6 is secondarily filled into the gap 5 through the filling tube 4, and the filling material 6 is poured into the filling tube 4 and closed after the filling.

  In the synthetic segment manufacturing method according to the third embodiment, the same effects as those of the first and second embodiments can be obtained, and the high-quality synthetic segment 1 in which the gaps 5 are filled can be manufactured. it can.

As mentioned above, although embodiment of the manufacturing method of the synthetic segment by this invention was described, this invention is not limited to said embodiment, In the range which does not deviate from the meaning, it can change suitably.
In the embodiment according to the present invention, the secondary filling method is a method of first providing the filling tube 4 at a position where the formation of the gap 5 is expected and a method of providing the through hole 21 secondly. Alternatively, either one of the second methods may be adopted, but secondary filling may be performed by both.
Further, in the synthetic segment manufacturing method according to the present invention, it is a concrete placing method by mountain driving in the first embodiment, ship driving in the second embodiment, and vertical driving in the third embodiment. It is not limited to these. Further, the placing method of the outer shell R at the time of placing is not limited to horizontal, but one may be higher as shown in the first modification.
Furthermore, the filling tube 4 may be provided at any position of the outer shell R. And also about the quantity of the filling pipe 4, it can attach according to how to put and the attitude | position of the outer shell R at the time of concrete placement. In short, it is only necessary to provide the filling tube 4 and perform the secondary filling to the gap 5 formed by the primary filling.

It is a perspective view of the synthetic segment by 1st embodiment of this invention. It is the sectional view on the AA line of the synthetic segment shown in FIG. FIG. 2 is a perspective view of an arcuate plate frame in the composite segment shown in FIG. 1. It is a longitudinal cross-sectional view which shows the state mainly filled with the concrete in the manufacturing process of the synthetic segment by 1st embodiment of this invention. It is the BB sectional view taken on the line of the synthetic segment shown in FIG. It is a figure which shows the state which laid concrete in the manufacturing process of the synthetic segment by the 1st modification of 1st embodiment. It is a figure which shows the secondary filling in the manufacturing method of the synthetic segment by the 2nd modification. It is a longitudinal cross-sectional view which shows the state with which it filled primarily in the manufacturing process of the synthetic segment by 2nd embodiment of this invention. It is the DD sectional view taken on the line of the synthetic | combination segment shown in FIG. It is a perspective view which shows the state mainly filled with the concrete in the manufacturing process of the synthetic segment by 3rd embodiment of this invention. It is a center longitudinal cross-sectional view which shows the state with which the concrete in the manufacturing process of the synthetic | combination segment shown in FIG. 10 was primarily filled.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Composite segment 2 Arc plate-shaped frame 3 Skin plate 4 Filling pipe 5 Cavity 6 Filler 15 Opening surface 17 Filling port 16a Form plate 21 Through-hole C Concrete P Air hole (passage)
R outer shell

Claims (4)

In the manufacturing method of the synthetic segment formed by placing concrete inside the steel arcuate plate frame,
An outer shell is formed by attaching a mold plate that closes the opening of the arcuate plate frame,
Next, the outer shell body is primarily filled with concrete,
Thereafter, the space between the inner surface of the outer shell body and the primary filled concrete is filled with concrete through a pre-arranged filling pipe to fill the void. Manufacturing method. When secondary filling concrete into the void using the filling tube,
2. The method of manufacturing a synthetic segment according to claim 1, wherein a passage through which the remaining air bubbles escape to the outside of the outer shell body is provided in the outer shell body. In the manufacturing method of the synthetic segment formed by placing concrete inside the steel arcuate plate frame,
An outer shell is formed by attaching a mold plate that closes the opening of the arcuate plate frame,
Next, the outer shell body is primarily filled with concrete,
Then, in the gap where air bubbles remain between the inner surface of the outer shell body and the primary filled concrete, a through hole is formed in the outer shell body to communicate with the outside, and the concrete is secondarily filled from the through hole. A method for producing a synthetic segment, wherein the gap is filled. In the synthetic segment formed by placing concrete inside the steel arc plate frame,
A synthetic segment comprising a filling pipe for secondary filling of concrete from the outside into a gap in which bubbles remain between the inner surface of the arcuate plate frame and the primary filling concrete.

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