Pressure Pipe

Abstract

To provide a concrete pressure-feed pipe capable of performing a pressure-feed test of concrete in narrow installation space and easily performing maintenance management work or the like.SOLUTION: A pressure-feed pipe is provided with two or more pressure-feeding units (a lower pressure-feed unit 10 and an upper pressure-feed unit 20), the pressure-feed units are arranged in parallel in a vertical direction, and the pressure-feed units adjacent to each other in the vertical direction are connected to each other, each pressure feed unit is composed of a plurality of straight pipes 11, 21 arranged in parallel in the horizontal direction and a plurality of connecting pipes 12, 22 connecting one end parts of the adjacent straight pipes 11, 21 to each other, and the pressure feed piping H is formed in a zigzag shape.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a pressure pipe for pressure-feeding concrete, the pressure pipe having a characteristic layout structure. [Background technology]

[0002] In the past, when constructing large-scale structures in the civil engineering field, such as tunnel construction, test pumping has been carried out before the start of construction, in which fresh concrete (hereinafter referred to as "ready mixed concrete") is pumped horizontally over long distances. In addition to the civil engineering field, test pumping has also been carried out in building construction when long-distance horizontal pumping is expected due to construction conditions. Test pumping is often carried out at an actual construction site with pipes lined up. However, there are cases where it is difficult to carry out tests at the pumping distance required for actual construction, such as when excavation work has not yet been completed in tunnel construction. In such cases, a separate test site has been secured and test pumping has been carried out simulating actual construction.

[0003] When evaluating the pumpability of ready-mix concrete (hereinafter referred to as "pumpability evaluation") by test pumping, it is necessary to understand the pressure loss in the pipe per meter of horizontal pipe during pumping (pressure loss in the pipe) as one of the evaluation indicators. The above-mentioned pressure loss in the pipe varies depending on various factors such as the mix (mixture), the fluidity of the fresh concrete, and the pipe diameter, but it is generally known that the pressure applied to the fresh concrete, especially in the case of lightweight concrete, causes the lightweight aggregate to absorb water and significantly reduces the fluidity. Furthermore, not only for lightweight concrete, but also when fresh concrete is subjected to unexpected high pressure, the pressure loss in the pipe may be significantly different from that shown in various old construction guidelines and guidelines. Therefore, when performing unprecedented long-distance horizontal pumping, it is necessary to reproduce the maximum pumping pressure during construction by test pumping to grasp the pressure loss in the pipe, and this is also stipulated in various construction guidelines.

[0004] In addition, as another evaluation index for pumpability evaluation, it is also important to examine the change in the fluidity of fresh concrete before and after pumping (for example, slump and slump flow) in order to identify problems during on-site construction. In particular, since the fluidity of lightweight concrete decreases significantly when subjected to high pressure, it is necessary to reproduce the maximum pressure expected during construction by test pumping and verify it through various tests. Incidentally, the above explanation has mainly been about lightweight concrete. However, for normal strength concrete and high strength concrete, etc., many aspects remain unclear regarding pumpability evaluation when subjected to higher pressures than before, and it is necessary to reproduce the maximum pressure by test pumping. Conventionally, such test pumping has been carried out using a pumping pipe arranged horizontally on a plane (hereinafter referred to as a "horizontal pipe") (Non-Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Non-Patent Document 1] Rieko Terauchi, Mitsunori Hayakawa, Hiroshi Jinnai, Shusuke Kuroiwa, Fundamental Study on Pumpability of Ultra-High Strength Concrete, Journal of Structural Engineering, Architectural Institute of Japan, Vol. 622, pp. 25-31, December 2007 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, construction works to consolidate urban traffic underground are increasing with the aim of forming compact cities. When constructing underground tunnels, the plan is to make the cross section as small as possible in order to reduce construction time and costs. In such cases, the cross section becomes difficult to travel with an agitator truck, and concrete construction is carried out by long-distance pumping. Furthermore, in recent years, the scale of construction has expanded, and ultra-long distance pumping of more than 1500m is required. In such cases, in order to perform test pumping in advance, it is difficult to verify on-site, so it is necessary to prepare a separate place to perform the test. However, it is difficult to meet the condition of a place that allows pumping tests of more than 1500m, and even if it can be met, there is a problem that it costs a considerable amount of money. Furthermore, depending on the installation conditions of the horizontal pipe or the properties of the ready-mixed concrete, problems such as blockage of the horizontal pipe may occur during test pumping. In such cases, if the horizontal pipe is installed in a vast installation space, it is difficult to identify the location of the blockage, and the corresponding work such as processing and transporting the blocked concrete after identifying the location of the blockage is also very complicated. The above problem becomes more pronounced as the pumping distance becomes longer.

[0007] The present invention has been made to solve the above-mentioned problems, and has an object to provide a concrete pressure-transport pipe that enables ready-mix concrete pressure-transport tests to be conducted in a small installation space and enables maintenance and management work to be easily performed. [Means for solving the problem]

[0008] The pressure-transfer piping of the present invention (hereinafter sometimes referred to as "this pressure-transfer piping") used to achieve the above-mentioned objective is a concrete pressure-transfer piping having two or more pressure-transfer sections arranged side by side in the vertical direction, with adjacent pressure-transfer sections connected so as to communicate with each other in the vertical direction, characterized in that each of the pressure-transfer sections has a spiral section or multiple bends arranged in the horizontal direction. Here, the spiral portion and the multiple bends are provided to ensure the pipe length, and the spiral portion may be based on a circle or a polygon such as a rectangle. The bends may have any suitable shape such as a zigzag or wave shape. Furthermore, the spiral portion or the bends may be provided partially.

[0009] The present pressure-feeding piping is a concrete pressure-feeding piping including two pressure-feeding sections each composed of a lower pressure-feeding section and an upper pressure-feeding section, and a connection section connecting the lower pressure-feeding section and the upper pressure-feeding section, and each pressure-feeding section is composed of a plurality of straight tubes arranged in parallel in the horizontal direction, and a plurality of connecting tubes connecting one ends of the adjacent straight tubes, and is formed in a zigzag shape, and the lower pressure-feeding section and the upper pressure-feeding section are supported on a mounting base so as to be approximately horizontal, and the upper pressure-feeding section and the lower ... lower pressure-feeding section and the lower pressure-feeding section are supported on a mounting base so as to be approximately horizontal, and the upper pressure-feeding section and the lower pressure-feeding section are supported on a mounting base so as to be approximately horizontal, and the lower pressure-feeding section and the lower pressure-feeding section are supported on a mounting base so as to be approximately horizontal, and the upper pressure-feeding section and the lower pressure The part , approximately the same shape In a zigzag shape The upper pumping section is formed in a cylindrical shape, and the upper pumping section is disposed so as to be inverted with respect to the arrangement direction of the lower pumping section.

[0010] According to this pressure-feeding piping, by configuring it to have multiple pressure-feeding sections, it is possible to ensure the pipeline length and reduce the occupied area in a plan view, thereby making it possible to reduce the installation space.

[0011] In addition, in this pressure pipe, Lower pressure section and the above Upper Pressure feed Department The pipes may be provided with a connecting portion for connecting the pipes, the connecting portion being configured with a plurality of bent pipes and a plurality of connecting straight pipes, and may be formed so as to have a constant gradient, that is, a predetermined angle.

[0012] According to this pressure-feeding piping, it is possible to construct a connection section with a constant gradient using multiple bend pipes and multiple connecting straight pipes, so that multiple pressure-feeding sections can be arranged vertically without the need for specially shaped piping or complicated installation work to connect each pressure-feeding section.

[0013] In addition, in this pressure-feeding piping, the straight pipes constituting the pressure-feeding section may be arranged in positions such that the straight pipes constituting adjacent pressure-feeding sections in the vertical direction do not overlap with each other in a planar view. Here, the positions not overlapping each other refer to a positional relationship in which the orthogonal projections do not overlap (intersect) in a plan view.

[0014] According to this pressure transport piping, the straight pipes in each pressure transport section are positioned so that they do not overlap with each other when viewed in a plane. Therefore, even if a problem such as a concrete blockage occurs at a specific location within the pipe, the vertical straight pipes do not become an obstacle and corrective work can be easily carried out.

[0015] Furthermore, in this pressure transport piping, the end of one of the multiple straight pipes that serves as a concrete discharge outlet and the end of one of the multiple straight pipes that serves as a concrete discharge outlet may be arranged in parallel, and the end of the straight pipe that serves as the concrete discharge outlet and the end of the straight pipe that serves as the concrete discharge outlet may be arranged on the same side. It should be noted that the above term "parallel" does not mean strictly parallel, but means approximately parallel.

[0016] The pumpability evaluation test of ready-mixed concrete is carried out by comparing the values ​​of slump, slump flow, air content, etc. of the ready-mixed concrete before and after pumping. In this pressure transport piping, the concrete discharge outlet at the starting end of the straight pipe and the concrete discharge outlet of the other straight pipe at the end of the straight pipe are located on the same side, which makes it possible to carry out pressure transport evaluation tests at the same location and enables the consolidation of equipment, thereby contributing to convenience. Effect of the Invention

[0017] According to the present invention, it is possible to provide a test concrete pressure transport pipe that enables concrete pressure transport tests to be performed in a small installation space and allows maintenance and management work to be easily performed. [Brief description of the drawings]

[0018] [Figure 1] FIG. 2 is a plan view showing a schematic diagram of the pressure feed pipe of the present invention. [Diagram 2] 2 is a cross-sectional view taken along the line XX in FIG. [Diagram 3] FIG. 2 is an enlarged view of part A in FIG. [Figure 4] FIG. 2 is an enlarged view of part B in FIG. [Diagram 5] FIG. [Figure 6] FIG. 2 is an enlarged view of part C in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, with reference to the drawings, a detailed description will be given of an embodiment of the pressure feed pipe H. In the description based on the drawings, the same elements are given the same reference numerals, and duplicated description will be omitted. For convenience of notation in the drawings, in Fig. 1 (a plan view showing the pumping piping in schematic form), the lower pumping section 10 is shown by a dotted line, the upper pumping section 20 by a solid line, and the connection section 30 by a two-dot chain line. In Fig. 1, the direction of the arrow indicates the direction in which the ready-mix concrete is pumped.

[0020] [Main pressure pipe] The pressure-feeding pipe H includes two pressure-feeding sections, a lower pressure-feeding section 10 and an upper pressure-feeding section 20, and a connection section 30 that connects the lower pressure-feeding section 10 and the upper pressure-feeding section 20 (FIGS. 1 and 2). The lower pumping section 10 is composed of seven straight tubes 11 of the same length and a total of six connecting tubes 12 (three at each end) provided to connect the ends of adjacent straight tubes 11. The straight tubes 11 are arranged substantially parallel to each other with a predetermined constant interval between adjacent straight tubes 11. The same U-shaped connecting tubes 12 are provided between the ends of adjacent straight tubes 11. In this way, the lower pumping section 10 is formed in a zigzag shape (a shape in which the ends are continuously bent to have a constant width (U-shaped)) by continuously combining multiple straight tubes 11 and multiple connecting tubes 12. In addition, the upper pressure delivery section 20 is composed of seven straight tubes 21 of the same length and a total of six connecting tubes 22 of the same shape that are provided to connect the ends of each adjacent straight tube 21, and is formed in a zigzag shape that is approximately the same as the lower pressure delivery section 10. Each of the straight pipes 11, 22 of the lower pumping section 10 and the upper pumping section 20 is formed by connecting a plurality of pipes of a predetermined length.

[0021] The lower pumping section 10 and the upper pumping section 20 are supported substantially horizontally on the installation stand 40 via brackets 50 (FIGS. 3 and 4). The installation rack 40 is an H-shaped steel with mounting holes 41a formed at predetermined locations on an upper flange 41, and is arranged side by side at predetermined intervals so as to be perpendicular to the straight pipes 11, 21. In addition, an auxiliary rack 42 is provided at a position on the upper flange 41 of the installation rack 40 that intersects with the upper pumping section 20 (FIG. 5). The auxiliary rack 42 is a steel material having a box-shaped cross section, and has mounting holes 42a (the upper mounting hole is not shown) formed on the upper and lower surfaces. The auxiliary rack 42 is attached by aligning the lower mounting hole 42a with the desired position of the mounting hole 41a of the installation rack 40, and using bolts 56 and nuts (not shown) (FIG. 5). The straight pipe 11 and the connecting pipe 12 of the lower pumping section 10 are supported by a bracket 50 at a position where they intersect with the installation stand 40. In addition, the straight pipe 21 and the connecting pipe 22 of the upper pumping section 20 are supported by a bracket 50 attached to the auxiliary stand 42.

[0022] The bracket 50 comprises a base portion 51 which is an H-shaped steel, a U-shaped metal fitting 54 for fixing the lower pressure-feeding portion 10 and the upper pressure-feeding portion 20, and vertical plates 53 interposed on both sides of the web 51c at the longitudinal middle portion of the base portion 51. Upper elongated holes 52a are formed in two locations on both sides of the vertical plate 51 in the longitudinal direction of one side of the upper flange 51a, which sandwiches the position of the web 51c. Lower elongated holes 52b are formed in a total of four locations on both sides of the lower flange 51b, which sandwich the position of the web 51c, in the longitudinal direction, and on both sides of the auxiliary plate 53. The U-shaped metal fitting 54 is installed between the two upper elongated holes 52a on both sides of the vertical plate 53 so that an opening is formed in the width direction of the upper flange 51a. The bracket 50 is attached by aligning the lower long hole 52b of the lower flange 51b with the desired position of the mounting hole 41a of the installation stand 40 or the desired position of the mounting hole 42a of the auxiliary stand 42, and by using bolts 56 and nuts (not shown). Reference numeral 55 denotes an intermediate plate provided between the straight pipes 11, 21, etc.

[0023] The straight pipes 11, 21 and connecting pipes 12, 22 that make up the lower and upper pressure-feeding sections 10 and 20, as well as the components of the connection section 30, are inserted into an opening in the center of a U-shaped metal fitting 54 of the bracket 50, and both ends of the U-shaped metal fitting 54 are clamped by bolts 56 and nuts (not shown) inserted into each upper long hole 52a of the upper flange 51a. In addition, the presence of the lower long hole 52b formed in the bracket 50 makes it possible to adjust the mounting position of the bracket 50 to the installation stand 40 and the auxiliary stand 42 to an appropriate position, and the presence of the upper long hole 52a makes it possible to adjust the mounting positions of the straight pipes 11, 21 and the connecting pipes 12, 22, etc. to the bracket 50 to appropriate positions.

[0024] The connection section 30 is formed from a lower pressure delivery section connecting straight pipe 31, two 90 degree bends 32, 38 (hereinafter referred to as "90 degree bends"; when distinguished, they will be numbered first and second), two 180 degree bends 34, 36 (hereinafter referred to as "180 degree bends"; when distinguished, they will be numbered first and second), and three intermediate straight pipes 33, 35, 37 (when distinguished, they will be numbered first to third) (Figures 1 and 6). The 90-degree bends 32 and 38 are formed by bend pipes with a bend radius of 90 degrees. The 180-degree bends 34 and 36 are formed by connecting two bend pipes with a bend radius of 90 degrees with a connector 6. 2, the second intermediate straight tube 35 and the second 180-degree bend portion 36, and the second 180-degree bend portion 36 and the third intermediate straight tube 37 are joined together to form a semicircular shape.

[0025] The lower pumping section connecting pipe 31 has one end connected to the end 11b of the straight pipe 11 in the lower pumping section 30, and extends in the longitudinal direction, and the other end connected to a first 90-degree bent section 32, thereby changing its direction by 90 degrees. The first 90-degree bent section 32 is connected to a first 180-degree bent section 34 via a first intermediate straight pipe 33, and the first 180-degree bent section 34 is connected to a second 180-degree bent section 36 via a second intermediate straight pipe 35. Furthermore, the second 180-degree bent section 36 is connected to a second 90-degree bent section 38 via a third intermediate straight pipe 37, and the second 90-degree bent section 38 changes its direction by 90 degrees toward the upper pumping section 20 and is connected to a start end 21a of the straight pipe 21 in the upper pumping section 20. The connection part 30 is supported in an appropriate position by brackets 50 attached to the installation stand 40 and the auxiliary stand 42, which are disposed in a direction perpendicular to the intermediate straight pipes 33, 35, and 37. The connection part 30 is formed so as to have a gentle, constant gradient from the start point of the lower pressure feed part connecting pipe 31 through each part to the end point of the second 90-degree bend part 38.

[0026] As mentioned above, side Pumping section 20 and below sideThe pumping section 10 is formed in substantially the same shape, but side The pumping unit 20 is side The upper pumping section 20 is disposed upside down with respect to the arrangement direction of the pumping section 10. The upper pumping section 20 is disposed directly above the lower pumping section 10, with the straight tubes 11 constituting the lower pumping section 10 and the upper pumping section 20 oriented parallel to each other and spaced a predetermined distance apart, and the upper pumping section 20 and the lower pumping section 10 are disposed substantially horizontally with their positions shifted so as not to overlap each other in a plan view. That is, in plan view, the straight pipe 21 (designated by reference symbol 21A) constituting one edge of the upper pumping section 20 is spaced apart at a predetermined distance from the straight pipe 11 (designated by reference symbol 11A) of the lower pumping section 10, the tip of which is the starting end 11a of the lower pumping section 10, and the straight pipe 21 (designated by reference symbol 21B) constituting the other edge of the upper pumping section 20 is spaced apart at a predetermined distance from the straight pipe 11 (designated by reference symbol 11A) of the lower pumping section 10, the tip of which is the starting end 11a of the lower pumping section 10. Department The other edge of the tube 10 is formed by a straight tube 11 (distinguished by the reference symbol 11B). Furthermore, the starting end 11a of the straight pipe 11A at the edge, which serves as the concrete discharge outlet in the lower pressure delivery section 10, and the ending end 21b of the straight pipe 21B at the edge, which serves as the concrete discharge outlet in the upper pressure delivery section 20, are arranged on the same side.

[0027] The starting end 11a of the straight pipe 11 constituting this pressure-transporting piping H is connected to a concrete pump P for pressure-transporting the ready-mixed concrete via a connecting pipe 61. Ready-mixed concrete supplied from a chute of an agitator truck (designated by reference character T1) can be supplied to this pressure-transporting piping H by the concrete pump P (FIG. 1). In this way, the lower pumping section 10 and the upper pumping section 20 are arranged in parallel in two stages in the vertical direction and are connected by the connection section 30. side The ready-mixed concrete supplied to the start end 11a of the straight pipe 11A of the pressure-feeding section 10 passes through the connection section 30 and flows upward. sideThe fluid is discharged from the terminal end 21b of the straight pipe 21B of the pressure-feeding section 20. In addition, in the upper part of Fig. side The agitator track (designated T2) downstream of the terminal end 21b of the straight pipe 21B of the pumping section 20 side It is used to dispose of the ready-mix concrete discharged from the pumping section 20.

[0028] [How to use this pressure pipe] First, a pumpability evaluation test (slump test, air content test, etc.) before pumping (hereinafter referred to as "pre-pumping test") is conducted using ready-mix concrete transported by agitator truck T1 before being supplied to the pumping pipe H. Next, the concrete pump P is operated to supply ready-mixed concrete to the concrete outlet, which is the starting end 11a of the straight pipe 11A in the lower pumping section 10. The supplied ready-mixed concrete passes through the inside of the pipe of the lower pumping section 10, the connection section 30, and the inside of the pipe of the upper pumping section 20, and is discharged from the concrete outlet, which is the end end 21b of the straight pipe 21B in the upper pumping section 20. Then, at the same location as the pre-pumping test, a pumpability evaluation test after pumping is conducted using the discharged ready-mixed concrete, and the properties of the ready-mixed concrete before and after pumping are evaluated.

[0029] [Effects of this pressure pipe construction] According to the present pressure delivery pipe H, the installation space can be reduced because the configuration includes the lower pressure delivery section 10 and the upper pressure delivery section 20, making it possible to reduce the area occupied in a plan view. Therefore, even if a part of the present pressure delivery pipe H becomes clogged, it is easy to identify the clogged part, and after identifying the clogged part, it is easy to carry out the corresponding work such as processing and transporting the clogged concrete. Furthermore, according to the present pressure delivery piping H, the straight pipes 11, 21 constituting the lower pressure delivery section 10 and the upper pressure delivery section 20 are arranged in positions that do not overlap with each other in a plan view. Therefore, even if a problem such as concrete blockage occurs in a specific location, the straight pipes 11, 21 arranged above and below do not get in the way, and dismantling unnecessary locations is not necessary, making it easy to perform the corresponding work.

[0030] In addition, according to this pressure-feeding piping H, it is possible to construct a connection section 30 with a constant gradient using bent sections 32, 34, 36, 38 using multiple bend pipes, a lower pressure-feeding section connecting straight pipe 31, and multiple intermediate straight pipes 33, 35, 37, so that the lower pressure-feeding section 10 and the upper pressure-feeding section 20 can be arranged in the vertical direction without the need for piping with a special shape or complicated installation work. In addition, since the concrete discharge outlet, which is the starting end 11a of the straight pipe 11A that constitutes the lower pressure delivery section 10, and the concrete discharge outlet, which is the ending end 21b of the straight pipe 21B that constitutes the upper pressure delivery section 20, are located on the same side, it becomes possible to carry out pumpability evaluation tests at the same location, which enables the consolidation of equipment, and thus contributes to convenience.

[0031] Although an example of a preferred embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and appropriate design changes can be made to each element within the scope of the present invention. In addition, this pressure transfer piping is an example of the minimum necessary components, and other necessary components may be added as long as they do not impair the effects of the present invention. Furthermore, this pressure-transport piping is not limited to the type of concrete, pressure-transport pressure, and horizontal conversion distance length for which the pumpability evaluation test is performed, and can be used with any type and mix of concrete and any test method.

[0032] In particular, there is no limit to the number and shape of the pumping units, so long as two or more pumping units are arranged in parallel in the vertical direction. The dimensions and shapes of the pumping units do not need to be the same, and the arrangement of the pumping units can be determined as necessary as long as it does not impede the effects of the present invention. In addition, the length dimensions, pipe diameters and numbers of the straight pipes, connecting pipes and bend pipes that constitute the pumping section and connection section, as well as the shapes and bending radii of the connecting pipes and bend pipes, can be optimized depending on the nature of the pumping performance evaluation test. Further, the straight pipe, the connecting pipe and the bent pipe may be a single pipe body, or may be formed by appropriately joining a plurality of pipe bodies. In addition, the gradient of the joints, etc. can be appropriately determined so as not to impede the fluidity of the concrete being pumped.

[0033] Furthermore, in the above embodiment, a connection section with a constant gradient is formed using a plurality of bent pipes and a plurality of connecting straight pipes, and adjacent pumping sections arranged side by side in the vertical direction are connected. However, the connection of each pumping section may be made by providing a gentle, constant, predetermined gradient to the straight pipes and connecting pipes that form each pumping section, ensuring a height difference between the start point and the end point, and connecting the end point of the lower pumping section to the start point of the upper pumping section, without providing a special connection section. [Explanation of symbols]

[0034] H Pressure pipe (main pressure pipe) 10 Lower pumping section 20 Upper pumping section 11,21 Straight pipe 11a,21a Starting end 11b,21b Termination part 12,22 Connecting pipe 30 Connection 31 Lower pressure section connecting straight pipe 32 First 90 degree bend 33 First intermediate straight pipe 34 First 180 degree bend 35 Second intermediate straight pipe 36 Second 180 degree bend 37 Third intermediate straight pipe 38 Second 90 degree bend 40 Installation stand 42 Auxiliary stand 50 Bracket 51 Base 52a Upper slot 52b Lower long hole 54 U-shaped bracket

Claims

1. A concrete pressure pipe including two pressure sections each including a lower pressure section and an upper pressure section arranged in parallel in a vertical direction, and a connection section connecting the lower pressure section and the upper pressure section, Each of the pumping sections is formed in a zigzag shape and includes a plurality of straight tubes arranged in parallel in a horizontal direction and a plurality of connecting tubes connecting one ends of adjacent straight tubes to each other. The connection portion is composed of a plurality of bent pipes and a plurality of connecting straight pipes, and is formed to have a constant gradient, Each of the straight pipes constituting the pressure-feeding section is The straight pipes constituting the lower pumping section and the upper pumping section are arranged in a positional relationship such that their orthogonal projections do not overlap with each other in a plan view, The lower pumping unit and the upper pumping unit are supported on a mounting stand so as to be substantially horizontal, A pressure pipe characterized in that the upper pressure section and the lower pressure section are formed in a zigzag shape of approximately the same shape, and the upper pressure section is arranged in an upside-down direction relative to the arrangement direction of the lower pressure section.

2. An end portion of a straight pipe among the plurality of straight pipes that serves as a concrete delivery outlet; Among the plurality of straight pipes, the ends of the straight pipes serving as concrete discharge ports are arranged in parallel, 2. The pressure pipe according to claim 1, wherein the end of the straight pipe serving as the concrete delivery outlet and the end of the straight pipe serving as the concrete discharge outlet are arranged on the same side.

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