JP2004360398A - Pipe body made of concrete, concrete segment and manufacturing method for concrete segment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To constitute a unified firm pipe body and facilitate positioning works at a site by exactly aligning the position of protrusions/recesses for application of shear force on the joint face of a concrete segment constituting the pipe body. <P>SOLUTION: The pipe body 10 made of concrete constituted by joining a plurality of the arcuate tabular concrete segments 12 in the peripheral direction is configured so that recessed sections 34 accommodating shear keys are formed on the peripheral end faces 18 of the concrete segments 12 and the shared shear keys are installed and joined in the mutual recessed sections 34 of the adjacent concrete segments 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a concrete pipe, a concrete segment, and a method for producing the same, which are used, for example, in a propulsion method for constructing a sewer underground.
[0002]
[Prior art]
As a method of constructing a sewer underground, a propulsion method is known in which a propulsion pipe is excavated while being pushed laterally into the ground from a vertical shaft erected underground. This is to build a required length of culvert by pushing a concrete pipe manufactured to a predetermined length at the factory while joining it to the rear end of the previously pushed pipe. Things. The pipes and the joints constituting such a propulsion pipe are required to have strength to withstand a reaction force when pushed into the ground and water tightness for preventing intrusion of groundwater or the like.
[0003]
[Problems to be solved by the invention]
In recent years, with the spread of common ditches in urban areas, larger-diameter sewers have been constructed. In order to construct a large-diameter sewer with a diameter of more than 3 m, for example, by the propulsion method, such a large-diameter pipe must be transported from the factory to the site, and then loaded into a shaft, and transported and handled. Work is difficult. Therefore, it is conceivable to adopt a segment structure in which the pipe is divided into a plurality of pieces in the circumferential direction, similarly to the concrete segment for tunnel construction used in the shield method.
[0004]
In this case, if it is divided into many segments, the joining work on site becomes difficult. For example, it is conceivable to make it into two half-split bodies, which can sufficiently reduce the load of transportation and handling work Can be. At this time, it is conceivable that irregularities are formed in these segments at the joint surfaces of the segments so as to apply a shear force applied to the tube body in the axial direction during the propulsion method. Such irregularities are also used for positioning when joining concrete segments to form a tubular body.
[0005]
[Problems to be solved by the invention]
However, in the case of the above segment structure, the following problems are expected.
(1) When manufacturing concrete segments, if the state of solidification of the concrete in the individual concrete segments is different, the positions of the irregularities are shifted from each other, which makes it difficult to perform the alignment work at the site, and at the same time, as a pipe body. Insufficient integration results in high performance as a propulsion tube.
(2) Although it is conceivable that a large number of the above irregularities are provided in order to withstand a large shear load, it is not easy to simultaneously align the concrete segments in an unstable state in which the concrete segments are suspended.
[0006]
The present invention has been made in view of the above-mentioned problems, and the position of the asperities for loading a shear force on the joint surface of the concrete segments constituting the pipe is strictly coincident with each other to form an integrated strong pipe. It is an object of the present invention to provide a concrete pipe, a concrete segment, and a method for manufacturing the same, which can be configured and facilitate the on-site alignment work.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a concrete pipe according to claim 1 is a concrete pipe formed by joining a plurality of arc-plate-shaped concrete segments in a circumferential direction, wherein the concrete segment A recess for accommodating a shear key is provided on a circumferential end surface of the concrete segment, and a common shear key is attached to and joined to the recess between adjacent concrete segments.
[0008]
In the invention according to claim 1, since the shearing key for applying the shearing force is used as a positioning member also at the time of positioning at the time of assembling on site, these are made as separate members from each segment, For example, a plurality of types having different dimensions are prepared, and can be used appropriately when assembling on site.
[0009]
According to a second aspect of the present invention, in the concrete pipe body according to the first aspect, a key receiving member having the recess is embedded in a circumferential end surface of the concrete segment. .
[0010]
According to the second aspect of the present invention, the recess is formed on the circumferential end face of the concrete segment by embedding the key receiving member having the recess having the size and shape compatible with the shear key in the concrete segment. .
[0011]
According to a third aspect of the present invention, in the concrete pipe body according to the first or second aspect, the plurality of arc plate-shaped concrete segments are a pair of concrete segments each having a semicircular cross section. Features.
[0012]
According to the third aspect of the present invention, a pair of concrete segments each having a semicircular cross-section are aligned, for example, vertically and aligned, and a shear key is arranged in the recess and joined to form a concrete pipe. A body is made.
[0013]
A concrete pipe according to a fourth aspect of the present invention is the concrete pipe according to any one of the first to third aspects, wherein a plurality of the recesses are formed on the circumferential end surface of the concrete segment, respectively. Is characterized in that at least two types of shear keys having different lengths are arranged.
[0014]
According to the invention as set forth in claim 4, two types of shear keys having different lengths are prepared, and when positioning at the time of assembling on site, the long shear key is arranged in a specific recess, so that the position is improved. The alignment work becomes easy.
[0015]
The concrete segment according to claim 5, wherein the concrete segment is an arc plate-shaped concrete segment, and a concave portion for accommodating a shear key is provided on a circumferential end surface, and a plurality of the concrete segments are arranged adjacent to each other, and the adjacent concrete segments are arranged. It is characterized by being used to construct a concrete pipe by mounting a common shear key in the recesses between the segments.
[0016]
According to the fifth aspect of the present invention, a concrete pipe is formed by transporting a concrete segment to a site and arranging and assembling a common shear key in a recess. Since the shear key is a separate member from each segment, for example, a plurality of types having different dimensions can be prepared and used appropriately when assembling on site.
[0017]
The invention according to claim 6 is a method for manufacturing a concrete segment according to claim 5, wherein a mold to be formed with the plurality of concrete segments is disposed adjacent to each other in a circumferential direction, and Injecting concrete into the formwork in a state where a common connecting member to be bridged between adjacent concrete segments is arranged on the circumferential end face portion, and removing the connecting member after the concrete is solidified, thereby forming the recess. It is characterized by forming.
[0018]
According to the invention described in claim 6, concrete segments to be joined to form the tube are manufactured from the same material under the same conditions. can do. Moreover, since concrete is poured into the formwork and solidified in a state where the common connecting member is arranged, the positions of the recesses exactly match. This makes it possible to set a small dimensional difference between the recess and the shear key, and to obtain a connection by the high-strength shear key. In addition, positioning at the time of joining can be easily performed.
[0019]
A method of manufacturing a concrete segment according to a seventh aspect is characterized in that, in the invention according to the sixth aspect, a key receiving member having the recess is attached to an end of the connecting member. .
[0020]
In the invention according to claim 7, a key receiving member having a recess having a size and shape compatible with the shearing key is embedded in the concrete comment, whereby a recess is formed on the circumferential end surface of the concrete segment. You.
[0021]
An eighth aspect of the present invention is directed to the concrete segment manufacturing method according to the seventh aspect, wherein the connecting member is detachably attached to a recess of the key receiving member.
[0022]
In the invention according to claim 8, after the concrete is solidified, by removing the connecting member, the recess for the shear key is formed, so that the space for the shear key can be used for the connecting member, The key receiving member can be formed compact.
[0023]
A method for manufacturing a concrete segment according to a ninth aspect is characterized in that, in the invention according to any one of the sixth to eighth aspects, the connecting member is broken when the concrete segment is die-cut.
[0024]
According to the ninth aspect of the present invention, when the concrete segment is die-cut, the connecting member is broken, so that labor such as cutting can be omitted, and the die can be cut in any direction.
[0025]
According to a tenth aspect of the present invention, in the method of the ninth aspect, the connecting member is provided with a fragile portion that facilitates breaking when the concrete segment is die-cut. Features.
[0026]
According to the tenth aspect of the present invention, since the connecting member is broken at the fragile portion, it is possible to leave a shape that makes it easy to remove the connecting member after the breaking.
[0027]
In the method for manufacturing a concrete segment according to the eleventh aspect, in the invention according to any one of the sixth to tenth aspects, the connecting member is engaged with a jig for removing the broken connecting member from the concrete segment. It is characterized in that an engaging portion is provided.
[0028]
According to the eleventh aspect of the present invention, the jig can be easily detached by engaging with the engaging portion of the broken connection member.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 are views showing a concrete pipe body for a propulsion pipe according to an embodiment of the present invention. FIG. 1 is a side view, FIG. 2 is a cross-sectional view taken along line AA of FIG. FIG. 3 is a sectional view taken along line BB of FIG.
[0030]
This concrete pipe (hereinafter also simply referred to as a pipe) 10 is formed by joining a pair of half-split concrete segments 12, 12, and the method used in the propulsion method is concrete. It is the same as the integrally molded tube. That is, the pipe body 10 is successively added to the rear end of the propulsion pipe pushed laterally from the bottom of the vertical shaft installed underground. Then, the rear end of the pipe 10 thus added is further pushed by a jack or the like to push in the propulsion pipe, which is sequentially extended to construct a sewer.
[0031]
A collar (steel strip) 14 surrounding the end protrudes from the concrete main body 10a by a predetermined length on the tip side (the side connected to the propulsion pipe, left side in FIG. 1) of the pipe body 10. Has been. On the other hand, on the rear end side (the side pressed by a jack or the like, the right side in FIG. 1), a small-diameter portion 16 having an outer diameter smaller than the other is formed with a length substantially equal to the protruding length of the collar 14. When the pipe 10 is added to the rear end of the propulsion pipe, the small-diameter portion 16 of the front pipe 10 and the collar 14 of the rear pipe 10 are fitted together, and a gap therebetween is filled with a filler.
[0032]
This pipe body 10 is formed by joining a pair of half-shaped concrete segments 12. By joining the concrete segments 12, 12 at a place close to the site, the work load when transporting and handling the integrated pipe 10 is reduced. For example, since the half-shaped concrete segments 12 and 12 can be conveyed in an overlapping manner, the required space on the carrier can be reduced. As described below, the concrete segments 12 and 12 are provided with a structure for joining the pair to form the tube 10.
[0033]
As shown in the cross-sectional view of FIG. 2, an annular hole 20 that extends in the circumferential direction and opens in a circumferential end surface (joining surface) 18 is formed by a sheath 22 in the concrete segments 12, 12. Thus, when the pair of concrete segments 12 and 12 are joined, the corresponding annular holes 20 communicate with each other, and in this example, four orbiting holes 24 penetrating through the pipe body 10 are formed. A part of the orbiting hole 24 opens into a concave portion 26 on the outer peripheral surface of the concrete segments 12, 12, and an anchor 28 is provided in the concave portion 26. Then, after joining the concrete segments 12, 12, a PC tendon 30 such as a PC steel material is inserted through the concave portion 26, tightened by a jack or the like, and fixed to the anchor 28, whereby the two concrete segments 12, 12 are joined together. The tension is applied between the joining surfaces 18 and in the circumferential direction.
[0034]
The collar 14 is fixed so as to cover a half circumference of each concrete segment 12 by embedding a reinforcing bar welded to the collar 14 in concrete. Concave portions are provided at the circumferential ends of the concrete segments 12, 12, and the collars 14 are connected to each other by placing a backing material in the concave portions and welding the ends of the collars 14.
[0035]
Opposite circumferential end faces 18 of the concrete segments 12, 12 are provided with recesses 34 for accommodating shear keys 32, respectively, as shown in FIG. And are attached. The main purpose of these shearing keys 32 is to apply a shearing force acting between the joint surfaces 18 of the concrete segments 12, 12 when propelling the pipe body 10 into the ground, and to use a high-strength material, For example, as shown in FIG. 4, both ends are formed into a truncated conical pin shape by a metal such as steel, resin, ceramics, or the like. Since the shear key 32 is also used for positioning when joining the concrete segments 12, 12, the tapered taper 36 makes it easier for the shear key 32 to enter the recess 34. As shown in FIGS. 4A and 4B, the shear keys 32 having different lengths are prepared and can be selected according to the situation. For example, by arranging a long one in the concave portion 34 of the position to be positioned first and a short one in the other concave portions 34 at the time of positioning and positioning them sequentially, the work can proceed smoothly.
[0036]
The recess 34 for accommodating the shearing key 32 is formed in a key receiving member 38 embedded in the concrete at the circumferential end faces 18 of the concrete segments 12, 12 as shown in the figure. That is, the key receiving member 38 has a conical surface 40 having the same taper as the end of the shearing key 32 and a concave portion 34 in which a cylindrical surface 42 for accommodating a cylindrical portion in the middle of the shearing key 32 is formed. Have been. The dimensional difference between the shear key 32 and the recess 34 of the key receiving member 38 is set to 0.1 mm or less in this embodiment, and when a shear force is applied between the joint surfaces 18, the shear key 32 Only force acts. A screw hole 44 is formed at the bottom of the recess 34 of the key receiving member 38, which will be described later. The key receiving member 38 has an enlarged diameter portion 46 formed at the end buried in the concrete so that the key receiving member 38 can resist a force acting in a shearing direction or a pulling out direction. It is planned. The key receiving member 38 can also be made of an appropriate material such as a metal, a resin, and a ceramic.
[0037]
Hereinafter, a process of manufacturing the above concrete segments 12, 12 will be described.
According to the manufacturing method of the present invention, a pair of concrete segments 12, 12 that are joined to each other to form the pipe body 10 are simultaneously manufactured. FIG. 5 is a plan view of the formwork 48 assembled for concrete segment production, and FIG. 6 is a side view. That is, the formwork 48 for manufacturing the pair of concrete segments 12 and 12 includes a bottom plate 50, a tubular outer frame 51 and an inner frame 52 erected thereon, and these outer frame 51 and the inner frame. It is roughly composed of a partition plate 54 that divides a cylindrical space defined by 52 into two along a vertical plane along the axis, and a top plate 56. In addition, a beam member 58 that connects the outer frame 51 and the inner frame 52, a reinforcing member 60 that supports the outer frame 51, and the like are provided.
[0038]
In the formwork 48, reinforcing bars for reinforcing the concrete segments 12, 12 are assembled by welding or the like. In addition, components to be integrated with concrete are attached to the formwork 48. That is, a steel strip-shaped collar 14 is arranged on the outer periphery of the bottom plate 50 side, and a sheath 22 forming an annular hole 20 is arranged in the middle part in the circumferential direction. Is attached with an anchor 28.
[0039]
Further, the partition plate 54 covering the circumferential end faces 18 of the concrete segments 12, 12 has a key receiving member 38 in which the recess 34 for the shearing key 32 is formed, as shown in FIG. 38 are attached in a state where they are connected by a rod-shaped connecting member 62. That is, as shown in FIG. 8, male screws 64 are formed at both ends of the connecting member 62, and the male screws 64 are screwed into screw holes 44 formed at the bottom of the recess 34 of each key receiving member 38. The key receiving member 38 is connected. The connecting member 62 has a certain degree of rigidity and is formed of a material that can be broken. Although this embodiment is made of resin, metal, ceramics, and the like can be appropriately used.
[0040]
Two slits (fragile portions) 66 are formed in the center of the connecting member 62 to facilitate breaking when the concrete segments 12 are separated. Further, flat surfaces (engaging portions) 68 parallel to each other are formed in a portion near the slit 66, and the member can be detached from the key receiving member 38 by rotating by engaging this member with a jig. It has become. As shown in FIG. 7B, a hollow steady rest member 70 that fills a gap around the connecting member 62 is mounted in the recess 34. The key receiving member 38 is first attached to the formwork 48 by inserting the connecting member 62 into a through hole formed in the partition plate 54 and screwing the key receiving member 38 to both sides thereof.
[0041]
Concrete is poured into the formwork 48 thus configured, solidified for a predetermined period of time, and then die-cut to obtain a pair of concrete segments 12,12. In order to separate the concrete segments 12, 12 joined by the connecting member 62, for example, one of the concrete segments 12, 12 is lifted by a crane or the like, or is opened right and left by a trolley or the like. Break at the part. Depending on the shape of the mold frame 48, the moving direction at the time of die-cutting may be limited, but in the method of the present invention, it can be moved in any direction and can be appropriately selected according to the situation. After that, the divided connecting member 62 remaining in the recess 34 is rotated using a jig and removed from the recess 34 together with the steady member 70. In this state, the shear key 32 can be mounted in the recess.
[0042]
In the method for manufacturing a concrete segment as described above, a pair of concrete segments 12 to be joined is manufactured by solidifying the same material under the same conditions. Therefore, since the pair of concrete segments 12 and 12 are obtained with the same size and shape, tight joining is possible, and the integrated high-strength tubular body 10 is configured. In addition, since the key receiving members 38 are solidified in a connected state, the positions of the corresponding key receiving members 38 between the joining surfaces 18 in the finally solidified state are exactly the same. Therefore, even if the dimensional difference between the shear key 32 and the key receiving member 38 is set to a small value, joining with the shear key 32 interposed is easily performed. As a result, the recess 34 and the shear key 32 fit tightly, so that a high shear force load capability is obtained.
[0043]
The concrete segments 12, 12 manufactured in this way can be transported in a divided state to the site, where they can be joined and integrated. Thereby, the trouble of transporting and handling the large tube 10 can be saved. At the time of joining, one side is placed with the joining surface 18 facing up, the adhesive and the shearing key 32 are arranged in the recess 34, and the adhesive and the filler for waterproofing are arranged on the joining surface 18. . Then, the other concrete segments 12, 12 are lifted thereon by a crane or the like, aligned, lowered, and joined. In this case, for example, by preparing two types of long and short shear keys 32 and adopting long ones at the four corners, the other short ones do not come into contact with the joining surface 18 and the alignment becomes easy. By using the shear key 32 as a separate member in this manner, which shear key 32 is to be adopted in which recess 34 can be appropriately selected according to the situation.
[0044]
In the above-described embodiment, the recess 34 is formed using the key receiving member 38. However, the connecting member 62 may be directly buried in the concrete and removed to form the recess 34. Good. Further, in this embodiment, the segment structure in which the pipe body 10 is divided into two parts has been described, but the present invention can be applied to concrete segments 12 divided into an arbitrary number of three or more. Further, in this embodiment, the case where the concrete pipe 10 is used as a propulsion pipe for a propulsion method has been described as a preferred example, but it can be used for any purpose as long as the spirit of the invention is met.
[0045]
【The invention's effect】
As described above, according to the present invention, since the shearing key for applying the shearing force is a separate member from each segment, for example, a plurality of types having different dimensions are prepared, and when assembled at the site, In this case, positioning at the time of joining can be easily performed. Further, since the concrete segments to be joined to form the tube are manufactured from the same material and under the same conditions, the dimensions match when joined, and a tightly joined tube can be obtained. In addition, since concrete is poured into the formwork and solidified with the common connecting member arranged, the positions of the recesses exactly match each other. With a high shear key.
[Brief description of the drawings]
FIG. 1 is a side view of a concrete pipe according to an embodiment of the present invention.
FIG. 2 is a sectional view taken along line AA of FIG.
FIG. 3 is a sectional view taken along line BB of FIG. 1;
4A and 4B are cross-sectional views showing a shear key and a key receiving member, wherein FIG. 4A shows a long shear key and FIG. 4B shows a short shear key.
FIG. 5 is a plan view of a mold for manufacturing a concrete segment.
FIG. 6 is a front view of a formwork for manufacturing a concrete segment.
7A and 7B are views showing a key receiving member connected by a connecting member, wherein FIG. 7A is a front view and FIG. 7B is a cross-sectional view.
8 (a) is a front view, FIG. 8 (b) is a side view, FIG. 8 (c) is a plan view, and FIG. 8 (d) is a sectional view.
[Explanation of symbols]
10 Concrete pipe 12 Concrete segment 18 Circumferential end surface (joining surface)
32 shear key 34 recess 38 key receiving member 44 screw hole 48 formwork 54 partition plate 62 connecting member 66 slit (fragile part)
68 Flat surface (engagement part)

Claims (11)

A concrete pipe body formed by joining a plurality of arc-plate-shaped concrete segments in a circumferential direction,
A recess for accommodating a shear key is provided on a circumferential end surface of the concrete segment,
A concrete pipe comprising a common shear key attached to and joined to the recesses of adjacent concrete segments. The concrete pipe according to claim 1, wherein a key receiving member having the recess is embedded in a circumferential end surface of the concrete segment. 3. The concrete pipe according to claim 1, wherein the plurality of arc-shaped plate-shaped concrete segments are a pair of concrete segments each having a semicircular cross section. 4. A plurality of said recesses are respectively formed in said circumferential end face of said concrete segment, and at least two types of shear keys having different lengths are arranged in these recesses. 3. The concrete pipe according to any one of 3. An arc-plate shaped concrete segment,
A recess for accommodating the shear key is provided on the circumferential end face,
A concrete segment used to construct a concrete pipe by arranging a plurality of said concrete segments adjacent to each other and mounting a common shear key in said recess between adjacent concrete segments. A method for producing a concrete segment according to claim 5, wherein
A formwork for molding the plurality of concrete segments is arranged adjacently in a circumferential direction,
Injecting concrete into the formwork in a state where a common connecting member bridged between adjacent concrete segments is arranged on a circumferential end surface portion of the formwork,
The method for manufacturing a concrete segment, wherein the recess is formed by removing the connecting member after the concrete has solidified. The method for manufacturing a concrete segment according to claim 6, wherein a key receiving member having the recess is attached to an end of the connecting member. The method according to claim 7, wherein the connecting member is detachably attached to a recess of the key receiving member. The method for manufacturing a concrete segment according to any one of claims 6 to 8, wherein the connecting member is broken when the concrete segment is die-cut. The method for manufacturing a concrete segment according to claim 9, wherein the connecting member is provided with a fragile portion that facilitates breaking when the concrete segment is die-cut. The concrete according to any one of claims 6 to 10, wherein the connecting member is provided with an engaging portion that engages with a jig for removing the broken connecting member from the concrete segment. Segment manufacturing method.

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