JP5411747B2 - Formwork for centrifugal molding of concrete segments - Google Patents

Description

  The present invention relates to a mold for centrifugal molding of a concrete segment.

  Conventionally, there is a centrifugal molding method as one of the manufacturing methods of a reinforced concrete (RC) segment applied in the shield method.

  For example, as one of the centrifugal molding methods, a plurality of ring partition members are disposed in the rotation axis direction inside the centrifugal mold, and a plurality of segment partition members are disposed in the circumferential direction. There is a type in which a segment of a plurality of rings is centrifugally molded by placing concrete while rotating the ring (for example, Patent Document 1).

  Alternatively, a pair of annular end frames that are detachably attached to both end portions of the inner diameter surface of the centrifugal mold of the centrifugal molding apparatus are provided, and a segment mold frame is disposed between the end frames, so that the arc-shaped outer peripheral surface and There are some which form a steel plate reinforcing type segment whose side surface is covered and integrated by a steel plate covering frame (for example, Patent Document 1, FIG. 2, FIG. 3, FIG. 4).

  In addition, the segment molding unit has a plurality of partition plates spanned between the end frames described above, and drives the centrifugal molding device to rotate the centrifugal molding die at a required speed, while supplying concrete from the outside with a concrete supply nozzle. Fill (for example, Patent Document 2, FIGS. 9, 10, and 11).

JP 2008-162273 A JP 2008-284751 A

  However, in the method in which concrete is directly placed in the centrifugal mold or the centrifugal mold in Patent Document 1 and Patent Document 2 as described above, the concrete is removed from the centrifugal mold until the concrete is sufficiently cured. The mold could not be removed from the centrifugal mold.

  This invention is made | formed in view of the said problem, and makes it a subject to provide the technique which can manufacture a concrete segment efficiently.

  The present invention employs the following means in order to solve the above-described problems.

A mold for centrifugal molding of a concrete segment that is detachably mounted in a centrifugal drum of a centrifugal molding device,
A pair of circular members;
The end portions are fixed to the inner surfaces of the pair of circular members in a state of being spanned between the pair of circular members so that the pair of circular members are arranged in parallel and coaxially with a certain distance therebetween. A plurality of partition members fixed detachably;
In a state where the plurality of partition members are fixed to the pair of circular members, at least one back plate sandwiched in a cylindrical shape by the pair of circular members;
including.

  According to one aspect of the present invention, the plurality of partition members are fixed by the fixing means in a state in which at least one back plate is sandwiched between the pair of opposed circular members arranged in a cylindrical shape. Forming molds can be assembled. After that, the assembled mold for centrifugal molding is placed in the centrifugal drum, and concrete is placed while the centrifugal drum is rotated. Concrete segments are manufactured. When the concrete is hardened to some extent, the mold for centrifugal molding can be taken out of the centrifugal drum and the concrete can be cured. Therefore, it is not necessary to pause the centrifugal drum until the concrete is cured. Therefore, the operation rate of the centrifugal drum can be increased and the manufacturing efficiency of the segment can be increased.

  In the assembled centrifugal mold, an RC segment can be obtained by placing concrete in a space surrounded by a circular member, a partition member, and a back plate.

  In one aspect of the present invention, an annular groove is formed on each inner surface of the pair of circular members, and each end portion in the width direction of the back plate is inserted into the groove on each inner surface. It can be configured to be sandwiched between the pair of circular members. As a result, the plurality of back plates can be properly held.

  In one aspect of the present invention, a plurality of annular grooves are formed on each inner surface of the pair of circular members, and each end portion in the width direction of the plurality of back plates is the plurality of the plurality of inner surfaces. It can be configured to be sandwiched between the pair of circular members in a state of being fitted into any one of the circular grooves. Thus, the size of the concrete segment to be manufactured can be easily changed by sandwiching the back plate according to the position of the circular groove.

  Moreover, in one aspect of the present invention, it may be configured to further include at least one plate-like member that is detachably attached in close contact with at least one of the plurality of partition members. If it does in this way, it can prevent that a concrete contacts the site | part which a partition member and a plate-shaped member closely_contact | adhere, and can perform the demolding work from the mold for centrifugal molding.

  Furthermore, in one aspect of the present invention, the plate-like member includes a first surface that is in close contact with the partition member, and a second surface from which at least one anchor member embedded in the concrete to be placed protrudes. It can comprise so that it may contain. If it does in this way, the concrete segment by which the 1st surface was made into the peripheral direction end surface of a concrete segment can be obtained. For this reason, since it is not necessary to detach | leave a plate-shaped member from a concrete segment after demolding, the removal operation | work of a plate-shaped member from a concrete segment can be abbreviate | omitted.

  Furthermore, in one embodiment of the present invention, a cylindrical body having a plane in which one axial end face is orthogonal to the axis and the other axial end face obliquely intersects the axis is divided according to the partition member. The plurality of spacers may be further included, and each of the spacers may be configured such that the one axial end surface is in contact with one inner surface of the pair of circular members. In this way, a segment ring corresponding to a curve having a taper can be produced.

According to another aspect of the present invention, a plurality of partition members are spanned between the pair of circular members by fixing each end of the plurality of partition members to each inner surface of the pair of circular members by a fixing means. And assembling a centrifugal mold with at least one back plate sandwiched between the pair of circular members in a cylindrical shape,
The centrifugal mold is placed in a centrifugal drum,
Concrete is placed in the mold for centrifugal molding while rotating the centrifugal drum,
After the placing, the centrifugal mold is removed from the centrifugal drum and the concrete is cured,
A concrete segment manufacturing method including disassembling the centrifugal mold.

  According to the present invention, segments can be manufactured efficiently.

The example of the segment ring comprised by the segment manufactured using the mold for centrifugal molding which concerns on embodiment is shown. The example of the segment which comprises the segment ring shown in FIG. 1 is shown. It is decomposition | disassembly explanatory drawing of the mold for centrifugal molding of the concrete segment which concerns on embodiment. It is a figure which shows the example of the partition member and the plate for mold removal shown in FIG. It is a figure which shows a part of inner surface of a circular member. It is sectional drawing of a pair of circular member in the state which clamped the backplate. It is explanatory drawing of the attachment state of the partition member with respect to a circular member, and the board for mold release. It is AA sectional drawing of FIG. It is the figure which looked at the centrifugal molding apparatus of the state in which the several mold for centrifugal molding was installed from the side surface. It is the figure which looked at the centrifugal molding apparatus shown in FIG. 8 from the front. It is a figure which shows the modification of the plate for mold removal. It is a figure which shows the modification of a circular member, and shows the circular member by which the some circular groove | channel was provided in the inner surface. FIG. 12A shows a state in which a plurality of spacers are arranged in the mold shown in FIG. 2, and a pair of circular members are cut into a semicircle and two back plates located on the near side are removed. Indicates the state. FIG. 12B schematically shows a state in which a plurality of spacers and joint members are viewed from the axial direction.

  Hereinafter, a concrete segment centrifugal mold and a concrete segment manufacturing method using the centrifugal mold according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1A and FIG. 1B show examples of concrete segments (hereinafter simply referred to as “segments”) manufactured using a mold for centrifugal molding. FIG. 1A shows a cylindrical segment ring 1, and FIG. 1B shows one of the segments (segment pieces) 2 that form the segment ring 1 shown in FIG. 1A.

In FIG. 1A, the segment ring 1 is formed of four segments 2A, 2B, 2C, and 2D manufactured by a centrifugal molding method (hereinafter, when the segments 2A, 2B, 2C, and 2D are not distinguished, “ The notation “Segment 2” is used.)
Each segment 2 is formed in an arc shape having two circumferential end faces 2a and 2b, and one end of the circumferential direction is covered with a metal member (joint member 12: described later). The end surface 2a is formed of a metal member.

Further, insert nuts 12d and 12d (see FIG. 3) for connecting the segments 2 to each other in the circumferential direction of the segment 2 are embedded on one end surface 2b side of each segment 2, and the end surface 2b has an insert Nut holes 2c and 2c of the nuts 12d and 12d are opened. On the other hand, the metal member having the other end surface 2a of the segment 2 is formed with through holes 12e and 12e for inserting through-piece connecting bolts (not shown) inserted into the nut holes 2c and 2c. The through holes 12e and 12e communicate with recesses 2d and 2d provided on the end surface 2a side of the segment 2. In this way, each bolt is inserted into the through holes 12e and 12e from the recesses 2d and 2d, and is inserted into the nut holes 2c and 2c provided on the end surface 2b of the other segment 2, and screwed into the insert nuts 12d and 12d. By doing so, the segments 2 are connected in the circumferential direction (connection between pieces).

  Each end face in the width direction of the segment 2 is provided with a plurality of holes 2e for connecting the segment ring 1 in the axial direction with an inter-ring joint (not shown). Further, a sealing member for water stop (for example, a ring-shaped rubber or a rubber cover) is hung over the entire side surface of the segment 2 on the end surface 2b in the circumferential direction and each end surface in the width direction of the segment 2. A groove 2f is formed. Further, the metal member has a groove 12g formed so as to be continuous with the groove 2f.

  Such a segment 2 (segment ring 1) is applied to tunnel construction using a shield method. For example, it is applied in the construction of water and sewage or common ditch. In tunnel construction, the segment rings 1 are assembled by connecting the segments 2A to 2D in the circumferential direction with bolts (inter-segment joints). Each segment ring 1 is arranged such that the outer peripheral surface of the segment ring 1 is in contact with the inner peripheral surface of the excavated tunnel, and a bolt (inter-ring joint) (not shown) is used in the axial direction of the tunnel (segment ring 1) using the hole 2e. ). The plurality of segment rings 1 connected in this way are used as pipes for water supply in water and sewage systems and common grooves.

  In FIG. 1, as an example of the segment, rectangular segment groups 2 </ b> A to 2 </ b> D in which the end surface of each segment 2 is parallel to the axis of the segment ring 1 are shown. However, it is also possible to manufacture a tapered segment (for example, ABK type, trapezoidal and parallelogram type, or a taper type corresponding to a curve) using the centrifugal molding form 10 of the present embodiment.

  FIG. 2 is an exploded view of a centrifugal mold 10 (hereinafter simply referred to as “form 10”) used to manufacture a plurality of segments 2 (2A to 2D) as shown in FIG. FIG.

  In FIG. 2, the mold 10 roughly includes a pair of circular members (ring members) 11, 11, a plurality of joint members 12 as a plurality of partition members, and a plurality of back plates 13.

  The pair of circular members 11 and 11 have the same configuration. The circular member 11 is a metal (for example, steel) flat plate formed in a circular ring shape. The circular member 11 has an outer surface 11a and an inner surface 11b, and the inner surface 11b is provided with a circular groove 14A into which the end in the width direction of the back plate 13 is inserted (see FIG. 4). Further, on the inner surface 11b, a ring-shaped convex portion 14B for forming the groove 2f (FIG. 1B) of the segment 2 is formed concentrically with the groove 14A inside the groove 14A.

  Each circular member 11 is provided with a plurality of through holes 15A at a predetermined interval. Each through-hole 15A is used as a bolt hole for fixing the joint member 12 to the circular member 11 with a bolt 16 which is a fixing means. Further, each circular member 11 is formed with a plurality of through holes 15B for forming the holes 2e of the segment 2. A buried hardware for an inter-ring joint is installed using the through hole 15B. In the example shown in FIG. 2, three through holes 15 </ b> B are formed between the through holes 15 </ b> A, and three holes 2 e are formed on the side surface of the segment 2. However, the number of holes 2e can be set as appropriate, and through-holes 15B corresponding to the number of holes 2e can be provided.

  After the assembly, the mold 10 is installed in the centrifugal drum 33 of the centrifugal molding device 30 (see FIG. 8). For this reason, the outer diameter of the pair of circular members 11, 11 has a size corresponding to the inner diameter of the centrifugal drum 33.

  Moreover, the ring width length L (FIG. 5) of the circular member 11 is formed to be equal to or greater than the thickness of the segment 2. Note that the circular member 11 in the present embodiment is formed by the circular member 11 in order to allow a device such as a concrete supply nozzle to pass through the mold 10 when the mold 10 is disposed in the centrifugal drum. The central part is greatly opened to form a ring. Therefore, the shape and number of the openings of the circular member 11 can be appropriately set in view of the situation when the centrifugal mold is placed in the centrifugal drum.

  FIG. 3 is a diagram illustrating a configuration example of the joint member 12. The joint member 12 was attached so as to extend in the same direction from both ends in the longitudinal direction of the inner surface 23a of the partition plate 12a and the inner surface 23a of the partition plate 12a, which is a flat plate member made of steel formed in a belt-like rectangle. It is formed in a U-shape including support plates 12b and 12b. The length of the partition plate 12 a in the longitudinal direction is formed by the width of the segment 2 formed by the mold 10. Through holes 12e and 12e for inserting bolts for connecting between the segments 2 and recesses 2d and 2d (FIG. 1B) for passing the bolts through the through holes 12e and 12e are formed in the middle portion of the partition plate 12a. Box opening members 12f and 12f are provided. In addition, a continuous groove 12g is formed on both end surfaces 21 and 21 in the longitudinal direction of the partition plate 12a and an outer surface 23b opposite to the inner surface 23a to which the longitudinal support plates 12b and 12b are attached. The groove 12g provided on the end surface in the longitudinal direction is provided so that the convex portion 14B provided on the inner surface 11b of the ring-shaped member 11 is inserted, and is continuous with the groove 2f (FIG. 1B) in the completed segment 2. Is provided. Each of the support plates 12b and 12b is a steel plate for fixing and supporting the joint member 12 to the pair of circular members 11 and 11, and has bolt holes 12c.

  The joint member 12 is configured so that each end of the joint member 12 faces the circular members 11 and 11 so that the pair of circular members 11 and 11 face each other with a predetermined interval (the length in the width direction of the segment 2). The inner surfaces 11b and 11b are detachably fixed by bolts 16 as fixing means (see FIGS. 2 and 6).

  That is, as shown in FIG. 6, the joint member 12 is disposed between the pair of circular members 11 and 11, and the bolt holes 12 c and 12 c of the support plates 12 b and 12 b and the through holes 15 A of the circular members 11 are positioned. The bolts 16 are fixed to the inner surface 11b of each circular member 11 by inserting the bolts 16 into the through holes 15A and the bolt holes 12c from the outer surface 11a side of the circular member 11 in the aligned state.

  As each support plate 12b of the joint member 12 is fixed to each circular member 11 with a bolt 16, the pair of circular members 11 and 11 face each other in parallel and coaxially at a predetermined interval as shown in FIG. It will be in an arranged state.

  The joint member 12 functions as a partition wall that defines the boundaries of the plurality of segments 2 manufactured by the mold 10 when the concrete is placed on the mold 10. That is, different segments 2 are formed on both sides of the partition plate 12a by placing concrete. By placing concrete, the joint member 12 is contacted or buried in the concrete and becomes a part of the segment 2 (see FIG. 1B).

In the example shown in FIG. 6, the partition plate 12 a of the joint member 12 is arranged in parallel to the axis of the circular member 11 in order to manufacture the segment 2 having no taper. On the other hand, when a segment having a taper (segment ring formed from an ABK-type segment or a trapezoidal and parallelogram segment piece) is manufactured, the partition plate 12a is inclined with respect to the axis of the circular member 11. Placed in.

  Moreover, the taper segment ring for curves can be easily produced by dividing | segmenting and installing a taper-shaped cylindrical member (spacer) inside a pair of circular members 11 and 11 (it mentions later for details). In short, by using the mold 10, it is possible to manufacture straight type and curved type segment rings formed from segment pieces of various shapes.

  In addition, in this embodiment, in order to simplify description, it is comprised so that each edge part of the coupling member 12 may be fixed with the one volt | bolt 16. FIG. However, in practice, in order to prevent the rotation of the joint member 12, each support plate 12b has a plurality of bolt holes 12c and is circular so that the end of the joint member 12 is fixed by a plurality of bolts. The members 11 and 11 are configured to have a plurality of through holes 15A corresponding to the plurality of bolt holes provided in each support plate 12b.

  Returning to FIG. 2, the back plate 13 is an arc-shaped member formed in accordance with the outer surface shape of the segment 2 in the longitudinal direction (ring circumferential direction). Each end 13a in the width direction of each back plate 13 is inserted into a groove 14A (FIG. 4) provided on the inner surface 11b of each circular member 11 when the joint member 12 is fixed to the pair of circular members 11 and 11. (See FIG. 5). And each edge part of the joint member 12 will be in the state clamped by the circular members 11 and 11 by fixing with the volt | bolt 16 between the circular members 11 and 11 (bolt-tightening). The annular groove 14A is formed so as to be concentric with the circular member 11, and the cylindrical body formed by the plurality of back plates 13 and the circular members 11, 11 are concentric (coaxial).

  6 shows a state in which the back plate 13, 13 is sandwiched between the pair of circular members 11, 11, and the joint member 12 is fixed by the bolts 16, 16. FIG. A section is shown.

  As shown in FIG. 6, in the fixed state of the joint member 12, the end faces 21, 21 in the longitudinal direction of the partition plate 12 a are provided in close contact with the inner faces 11 b, 11 b of the circular members 11, 11. Further, as shown in FIG. 7, in the fixed state of the joint member 12, the outer end surface 22 in the short direction of the partition plate 12 a is provided so as to be in close contact with the back plates 13 and 13.

  In this way, a space S surrounded by the circular members 11, 11, the partition plate 12 a and the back plate 13 is formed. The concrete is placed (filled) in the space S, and after being hardened, the segment 2 is removed (FIG. 1B).

  Moreover, as shown in FIG.6 and FIG.7, the front surface 17a of the demolding board 17 which is a demolding member with respect to the end surface 23b of the side in which the boxing members 12f and 12f of the partition plate 12a are not provided. 3) are installed so that they are in close contact. The demolding plate 17 is, for example, a thin steel plate, and has an outer edge shape that is substantially the same as the partition plate 12a.

  As shown in FIG. 3, through holes 17 b and 17 b corresponding to the through holes 12 e and 12 e of the partition plate 12 a are provided in an intermediate portion of the demolding plate 17. Further, grooves 17d and 17d corresponding to the grooves 12g of the partition plate 12a are provided on both end faces 17c and 17c in the longitudinal direction of the demolding plate 17, respectively. Further, on the back surface 17e of the demolding plate 17, a linear convex portion 17f for forming the groove 2f in the end surface 2b (FIG. 1B) of the segment 2 is provided along the longitudinal direction of the demolding plate 17. It has been.

Further, on the back surface 17e side of the mold release plate 17, insert nuts 12d and 12d are arranged with the nut holes 2c and 2c aligned with the through holes 17b and 17b. As a result, the nut hole 2c
2c are opposed to the through holes 12e and 12e of the partition plate 12. After that, for example, the bolts inserted into the through holes 12e and 12e from the respective recesses 12f and 12f are inserted into the nut holes 2c and 2c through the through holes 17b and 17b, and tightened with bolts. 17 and the insert nuts 12 d and 12 d can be fixed to the joint member 12. However, the demolding plate 17 and the insert nuts 12d and 12d may be fixedly arranged in the mold 10 using another fixing device. For example, as shown in FIG. 6, the demolding plate 17 is supported between the circular members 11 and 11 so as not to easily fall off due to the rotation of the mold 10. Alternatively, the demolding plate 17 may be bonded to the end surface 23b of the partition plate 12a. The demolding plate 17 is provided to prevent the concrete from being hardened while being in contact with the end surface 23b and from being firmly bonded to the end surface 23b and making the demolding operation difficult. However, the demolding plate 17 is not an essential component.

  In the example shown in FIG. 7, the back plates 13 and 13 that are in close contact with the end surface 22 of the partition plate 12 a are arranged with a gap therebetween, but even if the back plates 13 and 13 are in contact with each other. good.

  In the example shown in FIG. 2, an example using four back plates 13 is shown. On the other hand, the number of the joint members 12 can be adopted as the number of the back plates 13 if the space between the back plates 13 can be closed by the end face 22 of the joint member 12. For example, in the example shown in FIG. 2, two back plates can be applied, or one cylindrical back plate can be adopted. In the present embodiment, the groove 14A is formed as a continuous circular groove, but may be formed of a plurality of arc-shaped grooves arranged on the same circumference.

  Next, the manufacturing method of the segment 2 using the above-mentioned formwork 10 is demonstrated. In this manufacturing method, a plurality of segments 2 (segment pieces) forming a segment ring are molded at a time using a single mold 10 using an existing centrifugal molding apparatus that conforms to the standard of a fume tube having an outer diameter of about 3 m. An example will be described. In addition, the outer diameter of the segment ring 1 manufactured using the formwork 10 of this embodiment is 2-3 m, for example, and the width of the segment 2 is 0.5-1 m.

  First, the mold 10 is assembled. That is, in a state where the four back plates 13 and the four joint members 12 are sandwiched between the inner surfaces 11b, 11b of the pair of circular members 11, 11, each joint member 12 is a circular member with a bolt 16 as a fixing means. 11 is fixed by bolting. Thereby, the mold 10 is assembled. The mold member 10 can separate the circular members 11 and 11 and the joint member 12 by removing the plurality of bolts 16. In the assembly process of the mold 10, at least the number of molds 10 that can be arranged in the centrifugal drum 33 (FIG. 8) is assembled at a time.

  In the process of assembling the mold 10, reinforcing bars are arranged in the space S (FIGS. 6 and 7) surrounded by the circular members 11, 11, the partition plate 12 a and the back plate 13, or the piece-to-piece joint provided in the segment 2 And a mold for providing a space for a joint between rings, or a release agent can be applied to a portion where the space S is formed. The above-described demolding plate 17 and the insert nuts 12d and 12d are arranged at this time. Furthermore, the concrete placement space (space S) with high water-tightness can be formed by carrying out the water stop work between the members of the assembled formwork 10.

  8 is a side view of the centrifugal molding apparatus 30 to which the mold 10 is applied, and FIG. 9 is a front view of the centrifugal molding apparatus 30 shown in FIG. As shown in FIGS. 8 and 9, the centrifugal molding device 30 includes rollers 31 and 32 arranged in parallel, and a cylindrical centrifugal drum 33 placed on the rollers 31 and 32.

A cylindrical internal space 34 for installing the mold 10 is provided in the centrifugal drum 33, and the mold 10 can be attached to and detached from the centrifugal drum 33 while being coaxial with the centrifugal drum 33. It is attached. Also, as shown in FIG. 8, a plurality of molds 10 (three in FIG. 8) are arranged at a time in the centrifugal drum 33.

  The roller 31 is connected to a drive device (for example, a motor) (not shown), and rotates by obtaining power from the drive device via a chain or a belt. As the roller 31 rotates, the centrifugal drum 33 can rotate at a predetermined speed. During the rotation of the centrifugal drum 33, the concrete is poured into the mold 10 from the concrete supply device 35 disposed in the internal space 34 of the centrifugal drum 33.

  The concrete supply device 35 includes a pipe for supplying concrete passed in the centrifugal drum 33 in the axial direction, and a supply port for supplying concrete from above toward the space S of each mold 10 from the pipe. The concrete fed into the pipe falls into the space S below from each supply port, whereby the space S is filled with concrete. Thus, the concrete is filled (placed) in the space S of each mold 10 in the rotating centrifugal drum 33, and centrifugal compaction is performed. Instead of the concrete supply device 35, a belt conveyor can be applied.

  When a predetermined time has elapsed since the concrete is placed, the rotation of the roller 31, that is, the centrifugal drum 33 is stopped, and the concrete finish around the joint member 12 of each mold 10 is performed. At this time, the concrete finish can be performed using the short direction length of the joint member 12 (partition plate 12a) as a ruler, and the concrete finish can be easily performed.

  Thereafter, each mold 10 is removed from the centrifugal drum 33 and left for a predetermined time for curing. When each mold 10 is taken out from the centrifugal drum 33, a plurality of pre-assembled molds 10 can be immediately placed on the centrifugal drum 33 and the next placing step can be performed.

  When curing is completed, the mold 10 is disassembled to perform demolding work. At this time, the circular members 11 and 11 are detached by removing the bolts 16 from the mold 10. At this time, the cylindrical molded product is separated with the partition plate 12a as a boundary. Since the demolding plate 17 is in close contact with the end surface 23b of the partition plate 12a to prevent contact with the concrete end surface 23b, the cylindrical molded product can be easily divided into four pieces.

  Then, by removing the demolding plate 17 and the back plate 13 from each piece, a plurality of segments 2 for forming the segment ring 1 as shown in FIG. 1A can be obtained. The joint member 12 is used as it is as a part of the segment 2 (FIG. 1B). For this reason, demolding work can be simplified. Moreover, a finishing process is performed after the decomposition | disassembly into several pieces. In this finishing process, the joint member 12 is left at the end of the segment 2 and can serve as a ruler at the end finishing with reference to the length in the short direction of the partition plate 12a.

  According to the embodiment described above, the mold 10 has the back plate 13 sandwiched between the circular members 11, 11, and the outer surface of the segment 2 is molded by the back plate 13. That is, since the surface of the internal space 34 of the centrifugal drum 33 is not used as a part of the mold, the mold 10 is taken out from the centrifugal drum 33 before the curing is completed, and the centrifugal molding apparatus is used for the next segment production. be able to. That is, the downtime of the centrifugal molding device 30 can be shortened and the operation time can be lengthened. Thus, if a large number of molds 10 are prepared in advance, the number of segments that can be manufactured per predetermined time can be increased.

Further, the pair of circular members 11 and 11 and the plurality of back plates 13 constituting the mold 10 can be used repeatedly. For this reason, since the main steel materials required for manufacture of the segment 2 are the joint members 12, the steel material cost required for manufacture of the segment 2 can be suppressed. Therefore, since the formwork cost and the steel material cost can be suppressed, the segment 2 can be created at a low cost.

  Moreover, in this embodiment, it is comprised so that all the segment pieces 2A-2D which form the segment ring 1 may be manufactured with one mold frame 10, Furthermore, the axial direction length of the centrifugal drum 33 is considered. The length in the width direction of the segment 2 is determined so that the plurality of molds 10 can be installed. Thereby, the manufacturing efficiency of the segment ring 1 can be improved.

  Furthermore, according to this embodiment, the following problems that the above-described Patent Documents 1 and 2 have can be solved.

  (1) The steel material of the formwork remains on the five surfaces (back surface, four side surfaces) of the product (segment), and the product price becomes high.

  (2) The removal of the partition plate causes a defect at the end of the segment, and the roundness of the segment ring is lost.

  (3) Water tightness of the placement space is difficult to obtain, and water (Mizumi) tends to remain on the product surface.

  That is, for the problem (1), since only one side surface of the segment 2 is covered with the joint member 12, the amount of steel used for the segment 2 can be reduced, and the unit price of the segment 2 can be reduced. Can be lowered.

  Further, for the above problem (2), the joint member 12 and the mold release plate 17 are arranged at the segment end portion of the mold 10, and the joint member 12 is made a part of the segment 2 as it is. 17 may be peeled off from the segment 2 after the mold 10 is disassembled. Therefore, the segment 2 is not easily lost, and the roundness of the segment ring 1 can be improved.

  Furthermore, with respect to the above-mentioned problem (3), a water-stoppering space (space S: FIG. 7) is formed by applying a waterstop to the joint (joint part) between the members of the mold 10. can do. The mold 10 of the present embodiment can be modified as follows. FIG. 10 is a view showing a modification of the demolding plate. The demolding plate 17 described in this embodiment is used to facilitate demolding and is removed from the segment 2 as the final product.

  On the other hand, as shown in FIG. 10, the anchor member 17B is attached to the back surface (second surface) 17e opposite to the front surface (first surface) 17a to be brought into contact with the end surface 23b of the partition plate 12a of the demolding plate 17. The anchor member 17B may be embedded in the concrete by placing the concrete. In this case, the step of removing the demolding plate 17 from the segment can be omitted. Further, in this case, a groove 17g similar to the groove 12g of the partition plate 12 is formed on the front surface 17a of the mold release member 17, and is used for hooking the seal member to the segment 2.

  FIGS. 11A and 11B are cross-sectional views showing a modified example (circular member 11A) of the circular member 11. FIG. FIG. 11A shows a state in which a cross section when the circular member 11A according to the modification is cut in the diametrical direction is viewed from a direction orthogonal to the axial direction of the circular member 11A, and FIG. It is a perspective view of circular member 11A shown to a). As shown in FIGS. 11 (a) and 11 (b), a plurality of annular grooves (circular grooves) 14a, 14b and 14c into which the short portions in the width direction of the back plate 13 are inserted are formed on the inner surface 11b of the circular member 11A. be able to. In this case, the circular grooves 14 a, 14 b, and 14 c are formed to be concentric with the circular member 11.

  In such a circular member 11, a back plate 13 and a joint member 12 corresponding to the circular grooves 14a, 14b, and 14c are prepared. Then, by selecting the back plate 13 and the joint member 12 according to any of the circular grooves 14a to 14c to be used, segment rings having different outer diameter sizes can be manufactured using the same circular member 11A. For this reason, the cost required for the mold 10 can be suppressed.

  Furthermore, this embodiment can perform the following improvements. 12A and 12B are diagrams showing another embodiment of the centrifugal mold according to the embodiment, and schematically showing a state in which a plurality of spacers SP are attached in the mold 10. . FIG. 12A shows a pair of circular members 11 and 11 cut into a semicircular shape in a state where a plurality of spacers SP are arranged in the mold 10 shown in FIG. The state excluding the back plates 13 and 13 is shown. FIG. 12B schematically shows a state in which the plurality of spacers SP and the joint member 12 are viewed from the axial direction.

The plurality of spacers SP are obtained by dividing a cylindrical body having one end face orthogonal to the axis and the other end face obliquely with respect to the axis, and is formed using a steel material.
Each spacer SP is fixed by, for example, welding in a state where one end surface is in contact with one inner surface 11b of the circular member 11 with each joint member 12 interposed therebetween. However, you may make it fix using a volt | bolt etc.

  Although not shown, each spacer SP has a plurality of through holes communicating with the through holes 15B (FIG. 2) of the circular member 11, and the embedded hardware for the inter-ring joint is installed using each through hole. However, instead of the through hole, a hole is provided on the other end surface of the spacer SP at a position that is collinear with the through hole 15B in the axial direction, and the embedded hardware is installed using the hole. good.

  Although not shown, an annular convex portion corresponding to the annular convex portion 14B for forming the groove 2f (FIG. 1B) of the segment 2 is formed on the other end face of each spacer SP. The outer peripheral surface shape of each spacer SP is formed in accordance with the inner peripheral surface shape of the back plate 13.

  By applying such a plurality of spacers SP, a taper type segment ring in which one end surface is inclined with respect to the axis can be produced by the mold 10. Such a segment ring is used to install a pipe in accordance with a curved portion (curve) of a tunnel. Since the spacer SP is attached to the circular member 11 by simple welding, it can be easily detached from the circular member 11 and can be reused.

S ... Concrete placement space SP ... Spacer 1 ... Segment ring 2 ... Segments 2a, 2b ... End surfaces 2c, 2c ... Nut holes 2d, 2d ... Recess 2e ... Hole 2f ... Groove 10 ... Chain forming mold 11, 11A ... Circular member 12 ... Joint member (partition member)
12a ... partition plate 12b ... support plate 12c ... hole 12d ... insert nut 12e ... through holes 12f, 12f ... boxing member 13 ... back plate 13a ... width Direction end 14A ... groove 14B ... projection 15A ... through hole 15B ... bolt hole 16 ... bolt 17 ... demolding plate 17a ... demolding plate front 17b , 17b... Through holes 17c, 17c... End faces 17d, 17d, 17g in the longitudinal direction of the demolding plate 17e ... Back surface 17f of the demolding plate 17f. ... end face 22 in the longitudinal direction of the partition plate ... end face 23a in the short direction of the partition plate ... inner surface 23b of the partition plate ... outer surface 30 of the partition plate ... centrifugal molding devices 31, 32 ... Roller 33 ... Centrifuge drum 34 ... Internal space 35 ... Concrete supply Location

Claims (7)

A mold for centrifugal molding of a concrete segment that is detachably mounted in a centrifugal drum of a centrifugal molding device,
A pair of circular members;
The end portions are fixed to the inner surfaces of the pair of circular members in a state of being spanned between the pair of circular members so that the pair of circular members are arranged in parallel and coaxially with a certain distance therebetween. A plurality of partition members fixed detachably;
In a state where the plurality of partition members are fixed to the pair of circular members, at least one back plate that is coaxially sandwiched by the pair of circular members;
Formwork for centrifugal molding of concrete segments containing. The annular groove into which the edge part of the width direction of the said backplate is inserted is formed in each inner surface of the said pair of circular member in the state which the said pair of circular member clamps the said backplate. Formwork for centrifugal molding of the described concrete segment. A plurality of annular grooves having different diameters are formed on the inner surfaces of the pair of circular members,
In a state where the pair of circular members sandwich the back plate, an end in the width direction of the back plate is inserted into any one of the plurality of annular grooves provided on the inner surfaces of the pair of circular members. The form for centrifugal molding of a concrete segment according to claim 1. The formwork for centrifugal molding of a concrete segment according to any one of claims 1 to 3, further comprising at least one plate-like member that is detachably attached in close contact with at least one of the plurality of partition members. 5. The concrete according to claim 4, wherein the plate-like member includes a first surface that is brought into close contact with the partition member, and a second surface from which at least one anchor member embedded in the concrete to be placed protrudes. A mold for centrifugal molding of segments. A cylindrical body having a plane in which one axial end face is orthogonal to the axis and the other axial end face obliquely intersects the axis further includes a plurality of spacers divided according to the partition member; The formwork for centrifugal molding of a concrete segment according to any one of claims 1 to 5, wherein each spacer is attached with the one axial end face in contact with one inner face of the pair of circular members. By fixing the end portions of the plurality of partition members to the inner surfaces of the pair of circular members by the fixing means, the plurality of partition members are spanned between the pair of circular members facing each other in parallel and coaxially with a space therebetween. And assembling a centrifugal molding form in which at least one back plate is clamped coaxially between the pair of circular members,
The centrifugal mold is placed in a centrifugal drum of a centrifugal molding device,
Concrete is placed in the mold for centrifugal molding while rotating the centrifugal drum,
After the placing, the centrifugal mold is removed from the centrifugal drum and the concrete is cured,
A method for producing a concrete segment, comprising disassembling the centrifugal mold.

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