Formwork for manufacturing hexagonal segments

Abstract

To provide a hexagonal segment manufacturing formwork capable of continuing to form a high-quality hexagonal segment by accurately retracting an end plate portion when removing the mold even when used repeatedly many times.SOLUTION: A pair of end plate portions 14 are respectively disposed so as to advance and retract in a direction approaching and separating from each other via an end plate advancing and retracting mechanism 20 supported and provided by a base portion 30. The end plate advancing and retracting mechanism 20 includes: a retracting guide portion 23 including a slide guide shaft 21 provided by linearly extending in the advancing and retracting direction of the end plate portion 14 in a state where one end portion is fixed to a bottom plate portion 11 and another end portion is fixed to the base portion 30, and a bearing 22 provided so as to slide-move along the slide guide 21 in a state fixed to the end plate portion 14; and an advancing and retracting operation portion 25 that advances and retracts the pair of the end plate portions 14.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a formwork for manufacturing hexagonal segments, and more particularly to a formwork for manufacturing hexagonal segments having a face-side axial joint surface and a wellhead-side axial joint surface, and a pair of V-shaped circumferential joint surfaces. [Background technology]

[0002] The shield tunneling method using a shield machine is widely used as a method for constructing various types of tunnels in urban areas and plains. The shield tunneling method is a construction method in which the face at the tip of the shield machine is pressed down with mud, muddy water, compressed air, etc. while the ground is excavated with a cutter, and segments are successively installed in the axial and circumferential directions of the tunnel behind the shield machine to form a lining that covers the inner surface of the tunnel, and a tunnel is constructed underground from the starting shaft to the arrival shaft while obtaining a reaction force by pressing a shield jack against the front end of the assembled lining.

[0003] In recent years, from the viewpoint of improving the efficiency of construction work, etc., a shield construction method using hexagonal segments having a hexagonal planar shape instead of the generally used segments having a rectangular planar shape as segments constituting the lining covering the inner circumferential surface of a tunnel has been adopted (see, for example, Patent Document 1 and Patent Document 2). The hexagonal segment has a face-side axial joint surface and a wellhead-side axial joint surface that are arranged in parallel, and a pair of V-shaped circumferential joint surfaces consisting of a face-side oblique joint surface and a wellhead-side oblique joint surface that are arranged in a V shape so as to connect the ends on both sides of these axial joint surfaces (see Fig. 1). The hexagonal segments are assembled sequentially by overlapping the face-side axial joint surface and face-side diagonal joint surface of the hexagonal segment that is assembled first to the rear side of the tunnel excavation direction with the portal-side axial joint surface and portal-side diagonal joint surface of the hexagonal segment that is assembled next to the front side of the tunnel excavation direction, with the isosceles trapezoidal portion of each hexagonal segment, which is the forward half of the tunnel excavation direction, protruding alternately in a honeycomb pattern in the axial and circumferential directions of the tunnel (see, for example, Patent Document 3, Figure 4).

[0004] Furthermore, in shield construction using hexagonal segments, a shield jack is pressed against the axial joint surface on the face side of the alternately protruding isosceles trapezoidal parts of the hexagonal segments, and the shield machine is allowed to excavate while taking up the reaction force, while at the same time, work to assemble the subsequent hexagonal segment is carried out in the area between the adjacent isosceles trapezoidal parts against which the shield jack is pressed (see, for example, Patent Document 3, Figure 4).As a result, it is possible to carry out shield construction efficiently by continuously assembling the hexagonal segments while the shield machine is excavating, without having to interrupt the excavation process with the shield machine every ring to perform segment assembly work, as is done in shield construction methods using segments with a rectangular planar shape.

[0005] Furthermore, in the shield tunneling method using hexagonal segments, the connection between adjacent hexagonal segments is performed using connecting bolts that penetrate between the joint surfaces of the axial joint surface on the face side, the axial joint surface on the wellhead side, the diagonal joint surface on the face side, and the diagonal joint surface on the wellhead side (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3), so that it is possible to prevent the formation of unevenness due to bolt boxes for fastening the connecting bolts, which appears on the inner peripheral surface of the lining body made of segments having a rectangular planar shape, on the inner peripheral surface of the lining body made of hexagonal segments. In addition, since the inner peripheral surface of the lining body can be kept smooth, there is no need to further construct a secondary lining on the inside of the lining body made of hexagonal segments, preferably having a corrosion-proof layer applied on the inner surface, and the shield tunnel constructed by using the inner peripheral surface of the lining body made of hexagonal segments as it is as the inner peripheral surface of the tunnel can be effectively used, for example, as a sewer pipe for circulating water or a tunnel for a reservoir for temporarily storing rainwater.

[0006] Such hexagonal segments are preferably made of concrete, and the axial joint surface on the face side, the axial joint surface on the wellhead side, and the pair of V-shaped circumferential joint surfaces that are joined to each other in particular need to be formed with high precision, so a formwork for manufacturing hexagonal segments has been developed for this purpose (see, for example, Patent Document 4).

[0007] The formwork for manufacturing hexagonal segments described in Patent Document 4 comprises a bottom plate portion, a pair of side plate portions which form both sides of the hexagonal segment and are erected on the bottom plate portion to form a concrete pouring space, and a pair of end plate portions which form both ends of the hexagonal segment, and the pair of end plate portions are arranged so as to be movable in a direction away from the hexagonal segment formed by opening and closing means which includes an end plate slide shaft, a slide roller pin, a lower plate, a guide rail, a base, a guide roller, an opening and closing bolt, etc.

[0008] That is, while the end plate is guided in its moving direction by the forward / backward guide section formed by the end plate slide shaft and the slide roller pin, the guide rail provided on the underside of the lower plate is slid along the guide roller attached to the base by rotating the opening / closing bolt, thereby moving the lower plate relative to the base and retracting it in the direction away from the hexagonal segment (see Fig. 5). This prevents cracks or chips from occurring in the hexagonal segment when it is removed from the mold, especially at the joint corners between the bottom plate and the end plate. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 2596666 [Patent Document 2] Japanese Patent Application Publication No. 9-273395 [Patent Document 3] Patent No. 3253870 [Patent Document 4] Patent No. 3481769 Summary of the Invention [Problem to be solved by the invention]

[0010] However, in the conventional formwork for manufacturing hexagonal segments described above, the forward / backward guide portion that guides the movement direction of the end plate portion is arranged in the area below the bottom plate 52a, as shown in Figure 8, so that the protruding portion 51a toward the bottom plate 52a of the slide shaft 51, which is fixed as an integral part to the lower part of the end plate portion 50, is sandwiched between the upper and lower slide roller pins 53a, 53b supported by the support bracket 52b of the bottom plate portion 52, and the sandwiched protruding portion 51a of the slide shaft 51 slides between the upper and lower slide roller pins 53a, 53b, thereby guiding the forward / backward direction of the end plate portion 50. For this reason, when the formwork for manufacturing hexagonal segments is used repeatedly, the protruding portion 51a of the slide shaft 51, which protrudes in a cantilever-like manner over a considerable length, becomes prone to eccentricity or uneven load due to fatigue, and the portion of the slide roller pins 53a, 53b that move in a sliding manner becomes prone to lateral vibration (wandering) or rattling, which may make it difficult to accurately retreat the end plate portion 50 in a specified direction and separate it from the formed hexagonal segment in a stably manner.

[0011] In particular, in recent years, there has been a demand for constructing large shield tunnels with large inner diameters using hexagonal segments, and the area and thickness of each hexagonal segment tends to increase, while the number of hexagonal segments used is also increasing, leading to a large number of repeated use of formwork for manufacturing hexagonal segments. For this reason, there is a demand for the development of a technology that enables the end plate portions to be accurately retracted in a predetermined direction when demolded in a more stable state, thereby enabling the formation of high-quality hexagonal segments, even when the formwork for manufacturing hexagonal segments is used repeatedly many times.

[0012] To provide a formwork for manufacturing hexagonal segments that can continue to form high-quality hexagonal segments by enabling the end plate portion to be retracted in a specified direction with high precision and in a more stable state when demolded, even when used repeatedly multiple times. [Means for solving the problem]

[0013] The present invention relates to a formwork for manufacturing a hexagonal segment for forming, by pouring and hardening concrete, a hexagonal segment having a face-side axial joint surface and a wellhead-side axial joint surface, and a pair of V-shaped circumferential joint surfaces consisting of a face-side oblique joint surface and a wellhead-side oblique joint surface, which are arranged in a V shape so as to connect both ends of the pair of axial joint surfaces, the formwork comprising: a bottom plate portion having a curved portion along an inner peripheral surface of the hexagonal segment; a face-side side plate portion having a curved portion along the face-side axial joint surface, which are arranged upright on both side edges of the bottom plate portion, and a wellhead-side side plate portion having a curved portion along the wellhead-side axial joint surface, and a V-shaped portion along the V-shaped circumferential joint surface, which are arranged upright on both end edges of the bottom plate portion, the end plate section includes a pair of end plate sections and a base section that supports the bottom plate section, the side plate section and the end plate section as a whole from below, the face side plate section and the mineshaft side side plate section are arranged so that they can be advanced and retreated toward and away from each other via a side plate advancement / retraction mechanism supported by the base section, and the pair of end plate sections are arranged so that they can be advanced and retreated toward and away from the bottom plate section via an end plate advancement / retraction mechanism supported by the base section, the end plate advancement / retraction mechanism including an advancement / retraction guide section consisting of a slide guide shaft that is provided so as to extend linearly in the advancement / retraction direction of the end plate sections and a bearing that is fixed to the end plate sections and is slidable along the slide guide shaft, and an advancement / retraction operation section that advances and retreats the pair of end plate sections, The slide guide shaft of the advance / retract guide portion is attached with one end fixed to the bottom plate portion and the other end fixed to the base portion, and the bearing slides along the slide guide shaft, so that the end plate portion advances and retreats in the directions approaching and separating from the bottom plate portion, respectively. death, The slide guide shaft of the advance / retract guide portion is a columnar or cylindrical shaft member. The bearing is a cylindrical rolling bearing. The above objectives are achieved by providing a form for manufacturing hexagonal segments.

[0014] Furthermore, it is preferable that in the formwork for manufacturing hexagonal segments of the present invention, the advance / retract operating part of the end plate advancing / retracting mechanism is provided in the lower part of the apex of the V-shaped portion of the end plate portion, and the advance / retract guide parts of the end plate advancing / retracting mechanism are arranged symmetrically in a pair on both sides of the advance / retract operating part, and are each provided in the lower part of the hypotenuse on both sides of the V-shaped portion of the end plate portion.

[0015] In addition, in the formwork for manufacturing hexagonal segments of the present invention, it is preferable that the slide guide shaft of the advance / retreat guide section is a cylindrical or cylindrical shaft member, and the bearing is a cylindrical rolling bearing. Effect of the Invention

[0016] According to the formwork for manufacturing hexagonal segments of the present invention, even when used repeatedly multiple times, the end plate portion can be retracted in a specified direction with high precision and in a more stable state when removed from the formwork, making it possible to continue to form high-quality hexagonal segments. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a plan view of a mold for manufacturing a hexagonal segment according to a preferred embodiment of the present invention. [Diagram 2] FIG. 2 is a side view of a mold for manufacturing a hexagonal segment according to a preferred embodiment of the present invention, as viewed from the X direction in FIG. [Diagram 3] FIG. 2 is an end view of a mold for manufacturing a hexagonal segment according to a preferred embodiment of the present invention, as viewed from the Y direction in FIG. [Figure 4] 4 is a cross-sectional view taken along line AA in FIG. 3, illustrating the configuration of an end plate advancing / retracting mechanism. [Diagram 5] 5 is a cross-sectional view taken along line BB in FIG. 4 for explaining the configuration of an advancing / retracting operation unit of the end plate advancing / retracting mechanism. [Figure 6] 5 is a cross-sectional view taken along CC in FIG. 4, illustrating the configuration of an advance / retract guide portion of the end plate advance / retract mechanism. [Figure 7]FIG. 1 illustrates the configuration of a hexagonal segment formed using a formwork for manufacturing a hexagonal segment according to a preferred embodiment of the present invention, where (a) is a front view, (b) is a side view of (a) seen from direction D, (c) is a side view of (a) seen from direction E, and (d) is a circumferential end view of (a) seen from direction F. [Figure 8] 11 is a cross-sectional view illustrating the configuration of a reciprocating guide portion of a conventional end plate reciprocating mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The hexagonal segment manufacturing formwork 10 according to a preferred embodiment of the present invention shown in Figs. 1 to 3 is used as a formwork for forming hexagonal segments made of concrete that constitute a lining covering the inner surface of a shield tunnel for a reservoir that temporarily stores rainwater, by connecting a plurality of the hexagonal segments 40 in the axial direction (excavation direction) and circumferential direction of the tunnel and assembling them in a honeycomb shape. The shield tunnel for a reservoir is a large circular tunnel with an inner diameter of, for example, about 5000 mm, and each hexagonal segment 40 that forms the lining covering the inner surface of the tunnel is also large, with a width in the tunnel axial direction of about 1000 mm, a length in the tunnel circumferential direction of about 3000 mm, and a thickness of about 300 mm, and a large number of hexagonal segments 40 are used. The formwork 10 for manufacturing hexagonal segments of this embodiment has the function of enabling it to continue to form high-quality hexagonal segments in a precise and stable manner, even when it is used repeatedly multiple times to form such a large number of hexagonal segments 40.

[0019] The hexagonal segment manufacturing formwork 10 of this embodiment is a formwork for manufacturing segments to form, by pouring and hardening concrete, a hexagonal segment 40 (see Figures 7(a) to (d)) having a pair of V-shaped circumferential joint surfaces 45 consisting of a face-side axial joint surface 41, a wellhead-side axial joint surface 42, and a face-side oblique joint surface 43 and a wellhead-side oblique joint surface 44 arranged in a V shape so as to connect both ends of the pair of axial joint surfaces 41, 42, respectively. As shown in Figures 1 to 3, the hexagonal segment 40 has a curved shape along the inner peripheral surface thereof. The cut face side plate portion 12 has a curved portion 12a along the cut face side axial joint surface 41 of the hexagonal segment 40, and the cut face side plate portion 13 has a curved portion 13a along the cut face side axial joint surface 42, which are arranged upright on both side edges of the bottom plate portion 11, a pair of end plate portions 14 having V-shaped portions 14a along the V-shaped circumferential joint surface 45, which are arranged upright on both end edges of the bottom plate portion 11, and a base portion 30 that supports the bottom plate portion 11, the side plate portions 12, 13, and the end plate portions 14 as a whole from below. The face-side side plate 12 and the wellhead-side side plate 13 are arranged so that they can be moved toward and away from each other via a side plate advancing and retreating mechanism 32 supported by a base 30 (see Figs. 2 and 3), and the pair of end plates 14 are arranged so that they can be moved toward and away from the bottom plate 11 via an end plate advancing and retreating mechanism 20 supported by the base 30, as shown in Figs. 4 to 6. The end plate advancing and retreating mechanism 20 is arranged so that it can be moved toward and away from the bottom plate 11 via an end plate advancing and retreating mechanism 20 supported by the base 30. The end plate advancing and retreating mechanism 20 includes an advancing and retreating guide section 23 (see Fig. 6) consisting of a slide guide shaft 21 that is fixed at one end to the bottom plate 11 and the other end to the base 30 and extends linearly in the advancing and retreating direction of the end plate 14, and a bearing 22 that is fixed to the end plate 14 and is slidably provided along the slide guide shaft 21, and an advancing and retreating operation section 25 (see Fig. 5) that moves the pair of end plates 14 forward and backward.

[0020] In this embodiment, the slide guide shaft 21 of the advance / retreat guide portion 23 is preferably a columnar or cylindrical shaft member, and the bearing 22 is preferably a cylindrical rolling bearing (see FIG. 6).

[0021] In this embodiment, the hexagonal segment 40 formed using the hexagonal segment manufacturing formwork 10 is a segment preferably made of reinforced concrete having a hexagonal planar shape, which includes a face-side axial joint surface 41 and a wellhead-side axial joint surface 42 arranged in parallel, and a pair of V-shaped circumferential joint surfaces 45 consisting of a face-side oblique joint surface 43 and a wellhead-side oblique joint surface 44 arranged in a V-shape so as to connect both ends of these axial joint surfaces 41 and 42, as shown in Figures 7(a) to (d). The hexagonal segment 40 has a cross section along the face-side axial joint surface 41 and the wellhead-side axial joint surface 42 that is curved in an arc shape (see Figures 7(b) and (c)). In the hexagonal segment 40, the angle θ between the face-side oblique joint surface 43 and the wellhead-side oblique joint surface 44 at each V-shaped circumferential joint surface 45 is 120° (see Figure 7(a)). This makes it possible to arrange multiple hexagonal segments 40 in a honeycomb pattern in the axial and circumferential directions, with the face-side diagonal joint surface 43 and face-side axial joint surface 41 of a previously installed hexagonal segment 40 overlapping with the wellhead-side diagonal joint surface 44 and wellhead-side axial joint surface 42 of a subsequently installed hexagonal segment 40 without any gaps.

[0022] In addition, in this embodiment, as shown in Figures 7(a) to (d), an outer seal groove 46a for mounting a sealant is formed continuously around the entire circumference at a distance from the outer peripheral surface on the face-side axial joint surface 41, the wellhead-side axial joint surface 42, the face-side oblique joint surface 43 and the wellhead-side oblique joint surface 44 of the hexagonal segment 40, and an inner seal groove 46b for mounting a sealant is formed continuously around the entire circumference at a distance from the inner peripheral surface.

[0023] Furthermore, in this embodiment, the hexagonal segment 40 has cutout portions 46c for attaching caulking material formed continuously around the entire circumference of the face-side axial joint surface 41, the tunnel mouth-side axial joint surface 42, the face-side oblique joint surface 43 and the tunnel mouth-side oblique joint surface 44 along the edge portion on the tunnel inner surface side.

[0024] In this embodiment, the hexagonal segment 40 is provided with oblique bolt insertion holes 47a extending from both side regions of the face-side axial joint surface 41 toward the center of the mouth-side oblique joint surface 44 in parallel with the face-side oblique joint surface 43, as in the tortoise-shell-shaped segment (hexagonal segment) described in Japanese Patent No. 3253870. At the end of each oblique bolt insertion hole 47a on the face-side axial joint surface 41 side, a fastening recess 47b for fastening the head of a connecting bolt member (not shown) is formed with its opening surface opening to the face-side axial joint surface 41. At the portion of the face-side axial joint surface 41 closer to the face-side oblique joint surface 43 than each fastening recess 47b, a positioning recess 47c is provided. At the mouth-side axial joint surface 42 of the hexagonal segment 40, a positioning protrusion 47d is provided at a position corresponding to the positioning recess 47c in the side region on both sides.

[0025] In this embodiment, female screw holes 48a are provided in the center of a pair of face-side oblique joint surfaces 43 of the hexagonal segments 40. When the wellhead-side oblique joint surface 44 of the hexagonal segment 40 to be subsequently installed is superimposed on the face-side oblique joint surface 43 of the previously installed hexagonal segment 40, the female screw holes 48a are linearly connected to end openings 47e of the bolt insertion holes 47a provided in the subsequent hexagonal segment 40 on the side opposite to the fastening recesses 47b.

[0026] Furthermore, in this embodiment, similar to the tortoiseshell segment (hexagonal segment) described in Patent No. 3253870, for example, the face-side diagonal joint surface 43 and the shaft-mouth-side diagonal joint surface 44 of the hexagonal segment 40 are each provided with positioning guide convex portions 49a and guide concave portions 49b for guiding the subsequent hexagonal segment 40 to be positioned accurately in the gap between each pair of circumferentially adjacent isosceles trapezoidal portions of the previously installed hexagonal segment 40.

[0027] Furthermore, in this embodiment, the hexagonal segment 40 has a gripping hole 49c provided in the central part of its inner surface so that the hexagonal segment 40 can be gripped by an erector device (not shown) for assembly, and a pair of lifting insert fittings 49d, which enable the hexagonal segment 40 to be lifted, are provided and positioned in the side regions on both sides of the wellhead side axial joint surface 42.

[0028] In this embodiment, the hexagonal segment 40 having the above-mentioned configuration can be formed by pouring concrete into the hexagonal segment manufacturing formwork 10 shown in Figs. 1 to 3 and allowing it to harden. The formwork 10 for manufacturing hexagonal segments includes a bottom plate portion 11 having a bottom plate 11a which is a curved portion along the inner circumferential surface of the hexagonal segment 40, a face side side plate portion 12 having a side plate 12a which is a curved portion along the face side axial joint surface 41 of the hexagonal segment 40, and a wellhead side side plate portion 13 having a side plate 13a which is a curved portion along the wellhead side axial joint surface 42, each of which is arranged upright on both side edges of the bottom plate 11a of the bottom plate portion 11, a pair of end plate portions 14 having V-shaped end plates 14a which are V-shaped portions along the V-shaped circumferential joint surface 45, each of which is arranged upright on both end edges of the bottom plate 11a of the bottom plate portion 11, and a base portion 30 which supports the bottom plate portion 11, the side plate portions 12, 13, and the end plate portions 14 as a whole from below.

[0029] The bottom plate portion 11 is constructed by supporting and fixing a bottom plate 11a made of a steel plate curved in an arc along the inner peripheral surface of the hexagonal segment 40 from below by a plurality of steel supports 31 (see FIG. 2) erected from the base portion 30. Similar to the formwork for manufacturing hexagonal segments described in Japanese Patent No. 3481769, a plurality of shaft insertion members 33 (see FIG. 1) constituting a side plate advancing and retracting mechanism 32 are fixed to the steel supports 31 in a state extending in the width direction of the bottom plate 11a. By inserting and supporting a side plate slide shaft 34 (see Figure 1) that constitutes a side plate advancement / retraction mechanism 32, which is fixed to the face side side plate portion 12 and the mouth side side plate portion 13 at positions corresponding to these shaft insertion members 33 and extending in the width direction of the bottom plate 11a, into and supporting the multiple shaft insertion members 33 in a manner that allows the side plate 12a of the face side side plate portion 12 and the side plate 13a of the mouth side side plate portion 13 to be moved away from the side edge portion of the bottom plate 11a or abutted against the side edge portion of the bottom plate 11a.

[0030] In addition, a fixed rib plate 11b is attached to the end edge portion of the bottom plate 11a constituting the bottom plate portion 11, where the end plate portion 14 abuts, in a state extending parallel to the end plate 14a from the lower surface side and protruding downward, to which one end of the slide guide shaft 21 of the advance / retract guide portion 23 described later is fixed, as shown in Fig. 6. The fixed rib plate 11b is firmly attached as one unit to the lower side of the bottom plate 11a by welding or the like, in a state reinforced by a reinforcing rib plate 11c fixed to the bottom plate 11a by welding or the like. In addition, a gripping hole insert member 11d for forming a gripping hole 49c in the center of the inner surface of the hexagonal segment 40 is attached in an upright state to the center of the upper surface side of the bottom plate 11a, as shown in Figs. 1 and 3.

[0031] The face-side side plate 12 and the wellhead-side side plate 13 include a face-side side plate 12a and a wellhead-side side plate 13a having an inner surface curved in an arc shape as a curved shape part along the face-side axial joint surface 41 and the wellhead-side axial joint surface 42 of the hexagonal segment 40, and a face-side support wall portion 12b and a wellhead-side support wall portion 13b extending integrally below the face-side side plate 12a and the wellhead-side side plate 13a to the lower region of the bottom plate 11a. The face-side side plate 12a and the wellhead-side side plate 13a are integrally joined to the upper edge portions and both end edges of the face-side side plate 12a and the wellhead-side side plate 13a so as to protrude vertically outward, and are fixed thereto by welding or the like, and radial reinforcing plates 12d and 13d (see FIG. 2) are integrally joined to the outer surfaces of the face-side side plate 12a and the wellhead-side side plate 13a and fixed thereto by welding or the like. This provides strong reinforcement to the side plate 12a on the face side and the side plate 13a on the mouth side.

[0032] In this embodiment, a pair of convex sockets 12e are attached to the inner surface of the side plate 12a of the face-side side plate portion 12 for forming positioning concave portions 47c on the face-side axial joint surface 41 of the hexagonal segment 40 (see FIG. 1). A pair of concave plugs 13f are attached to the inner surface of the side plate 13a of the mouth-side side plate portion 13 for forming positioning convex portions 47d on the mouth-side axial joint surface 42 of the hexagonal segment 40.

[0033] A side plate slide shaft 34 (see FIG. 1) constituting a side plate advancement / retraction mechanism 32 similar to the side plate advancement / retraction mechanism of the hexagonal segment manufacturing formwork described in the above-mentioned Japanese Patent No. 3481769 is integrally joined to the face side support wall 12b and the mouth side support wall 13b. The side plate slide shaft 34 is inserted and supported by a shaft insertion member 33 (see FIG. 1) fixed to a steel support 31 erected from the base 30, which supports the bottom plate 11a of the bottom plate 11. By operating a known advance / retraction operation unit 35 (see FIGS. 1 and 3), the face side side plate 12a integrated with the face side support wall 12b and the mouth side side plate 13a integrated with the mouth side support wall 13b can be moved forward and backward in the direction of approaching and separating from each other.

[0034] As shown in Fig. 1 and Fig. 3, the pair of end plate portions 14 arranged on both longitudinal edge portions of the bottom plate portion 11 each include an end plate 14a having an inner surface bent in a V shape as a V-shaped portion along the V-shaped circumferential joint surface 45 of the hexagonal segment 40, and an end plate support wall portion 14b extending integrally below the end plate 14a to the lower region of the bottom plate 11a. A band-shaped outer peripheral reinforcing plate 14c is integrally joined to the end plate 14a from the upper edge portion and both edge portions so as to protrude vertically outward in the forward and backward direction and fixed thereto by welding or the like, and a vertical reinforcing plate 14d (see Fig. 3) is integrally joined to the outer surface of the end plate 14a and fixed thereto by welding or the like.

[0035] In addition, in this embodiment, an oblique side convex socket 14h and an oblique side concave plug 14i are attached to the inner surface of the end plate 14a of the end plate portion 14, respectively, to form a positioning guide convex portion 49a and a guide concave portion 49b on the face side oblique joint surface 43 and the mouth side oblique joint surface 44 of the hexagonal segment 40 (see Figure 1).

[0036] 3 and 4, the end plate support wall 14b of the end plate 14 is provided with the advance / retract bolt 25a and the like which constitute the advance / retract operation part 25 of the end plate advance / retract mechanism 20, which is disposed at the top of the V-shape, and the bearings 22 and the like which constitute the advance / retract guide part 23 of the end plate advance / retract mechanism 20 are disposed at the center of each of a pair of oblique sides of the V-shape. That is, in this embodiment, the advance / retract operation part 25 of the end plate advance / retract mechanism 20 is preferably provided at the lower part of the top of the end plate 14a which forms the V-shaped part in the end plate 14, and the advance / retract guide parts 23 of the end plate advance / retract mechanism 20 are preferably provided symmetrically in pairs on both sides of the advance / retract operation part 25, and are preferably provided at the lower parts of the oblique sides on both sides of the end plate 14a which forms the V-shaped part in the end plate 14.

[0037] 4 and 5, the advancing / retreating operation unit 25 of the end plate advancing / retreating mechanism 20 has a similar configuration to the advancing / retreating operation unit of the end plate of the formwork for manufacturing a hexagonal segment described in the above-mentioned Japanese Patent No. 3481769. The advancing / retreating operation unit 25 is configured to move the pair of end plate portions 14 in the direction of approaching and separating from the bottom plate portion 11 by tightening or loosening the advancing / retreating bolt 25a attached to the end plate support wall portion 14b of the end plate portion 14, and thereby move the guide rail 25b provided on the lower surface of the lower plate 14j of the end plate support wall portion 14b via the guide roller 25d supported by the pedestal 25c provided on the base 30 by rotating the guide roller 25d (see the dashed line portion in FIG. 5).

[0038] In this embodiment, as shown in Figures 4 and 6, the advance / retract guide portion 23 of the end plate advance / retract mechanism 20 is configured to include a slide guide shaft 21 having one end fixed by welding or the like to the fixed rib plate 11b of the bottom plate portion 11 and the other end fixed by welding or the like to a support bracket 36 attached to the base portion 30, and a bearing 22 fixed to the end plate support wall portion 14b of the end plate portion 14.

[0039] The slide guide shaft 21 is preferably a columnar or cylindrical metal shaft member, and one end of the slide guide shaft 21 is fixed to the fixed rib plate 11b and the other end of the slide guide shaft 21 is fixed to the support bracket 36, so that the slide guide shaft 21 is firmly attached in a state of extending linearly in the advancing / retreating direction along the length direction of the hexagonal segment 40, which is preferably perpendicular to the V-shaped circumferential joint surface 45 of the hexagonal segment 40 that moves the end plate portion 14 forward and backward. That is, the fixed rib plate 11b is firmly fixed to the bottom plate 11a of the bottom plate portion 11 supported and fixed to the base portion 30 via the steel support 31, as described above, via welding or the like, and the support bracket 36 is also firmly fixed to the base portion 30 via welding or the like, so that the slide guide shaft 21, both ends of which are firmly fixed to these members, can be firmly and stably maintained in a state of extending linearly in the advancing / retreating direction.

[0040] The bearing 22 is a component that receives a load from a rotating or reciprocating mating component and is supported on a shaft or the like, and is preferably a rolling bearing such as a ball bearing. More specifically, it is preferable to use a linear bushing that can be used in combination with a cylindrical shaft to form a linear motion system capable of infinite linear motion.

[0041] In this embodiment, the bearing 22 is firmly fixed as one unit to the end plate support wall portion 14b by, for example, fixing the outer cylindrical portion 22a to a support plate 14f of a support stand 14e provided on the end plate support wall portion 14b of the end plate portion 14 by welding or the like, with the slide guide shaft 21, which is a cylindrical shaft with both ends fixed, inserted inside the outer cylindrical portion 22a. This allows the end plate portion 14 to be guided by the slide guide shaft 21 via the bearing 22 and to move precisely and smoothly along the length direction of the hexagonal segment 40, preferably in a direction perpendicular to the V-shaped circumferential joint surface 45 of the hexagonal segment 40 to be formed.

[0042] In this embodiment, a slide roller 38 supported by a roller support bracket 37 is attached to the base portion 30 directly below the end plate portion 14 adjacent to the support bracket 36 (see FIG. 6). A slide rail 14g provided on the lower end surface of the end plate support wall portion 14b of the end plate portion 14 abuts against the slide roller 38, allowing the end plate portion 14 to slide along the slide roller 38. This allows the end plate portion 14 to be moved forward and backward smoothly in a more stable state along the length direction of the hexagonal segment 40, preferably in a forward and backward direction perpendicular to the V-shaped circumferential joint surface 45 of the hexagonal segment 40 to be formed.

[0043] To form a hexagonal segment 40 using the hexagonal segment manufacturing formwork 10 of this embodiment having the above-mentioned configuration, the end plate 14a of the end plate portion 14 and the side plates 12a, 13a of the side plate portions 12, 13 are advanced and retreated by the end plate advancement and retreat mechanism 20 and the side plate advancement and retreat mechanism 32 described above, and these are brought into contact with both end edges and both side edges of the bottom plate 11a of the bottom plate portion 11 in an upright state, thereby forming a casting space for pouring concrete above the bottom plate 11a. In addition, reinforcing steel bars are appropriately arranged in the formed casting space, and as shown in FIG. 1, a sheath tube 26 for forming a diagonal bolt insertion hole 47a in the hexagonal segment 40, a female screw anchor 27 for forming a female screw hole 48a, and a lifting insert metal fitting 49d for lifting the hexagonal segment 40 are installed, for example, by supporting the reinforcing steel bars or block members. Thereafter, concrete is poured into the casting space above the bottom plate 11a, and the outer circumferential surface of the poured concrete is finished with a trowel so as to conform to the arc-shaped curved surface.

[0044] After the poured concrete has hardened and a predetermined curing period has elapsed, the end plate 14a of the end plate portion 14 and the side plates 12a, 13a of the side plate portions 12, 13 are advanced and retreated by the end plate advancing and retreating mechanism 20 and the side plate advancing and retreating mechanism 32, respectively, to move them back and away from the hardened concrete, thereby removing them from the formwork. This makes it possible to easily remove the formed hexagonal segment 40 from the hexagonal segment manufacturing formwork 10.

[0045] Furthermore, according to the formwork 10 for manufacturing hexagonal segments of this embodiment having the above-mentioned configuration, even if it is used repeatedly multiple times, the end plate portion can be retracted in a specified direction with high precision and in a more stable state when removed from the mold, making it possible to continue to form high-quality hexagonal segments.

[0046] That is, according to this embodiment, the advance / retract guide portion 23 of the end plate advance / retract mechanism 20, which advances and retracts a pair of end plate portions 14 in directions approaching and moving away from the bottom plate portion 11, is composed of a slide guide shaft 21 extending linearly in the advance / retract direction of the end plate portions 14, with one end fixed to the bottom plate portion 11 and the other end fixed to the base portion 30, and a bearing 22 fixed to the end plate portion 14 and arranged to be slidable along the slide guide shaft 21.

[0047] As a result, according to this embodiment, by guiding each end plate portion 14 along the advance / retract guide portion 23 during demolding, the advance / retract operating portion 25 can accurately move each end plate portion 14 back in a straight line along the length of the hexagonal segment 40 being formed, preferably in an advance / retract direction perpendicular to the V-shaped circumferential joint surface 45 of the hexagonal segment 40.This makes it possible to effectively prevent cracks and chips from occurring at the corners of the joints between the bottom plate 11a of the bottom plate portion 11 and the end plate 14a of the end plate portion 14 during demolding.In particular, even if positioning guide convex portions 49a and guide concave portions 49b are formed on the face side diagonal joint surface 43 and the minehead side diagonal joint surface 44 of the V-shaped circumferential joint surface 45 of the hexagonal segment 40, it is possible to effectively prevent cracks and chips from occurring at these uneven portions during demolding.

[0048] According to this embodiment, the forward and backward guide section 23 consisting of the slide guide shaft 21 and the bearing 22 is fixed at both ends of the slide guide shaft 21, which is preferably a columnar or cylindrical shaft member, to the fixed rib plate 11b of the bottom plate section 11 and the support bracket 36 of the base section 30, respectively, and is firmly attached by extending linearly with high accuracy in the forward and backward direction of the end plate section 14, and the bearing 22, which is preferably a near bush, is firmly attached to the support stand 14e provided on the end plate support wall section 14b of the end plate section 14, and is stably mounted along the slide guide shaft 21. Since the end plate 14 can slide in a stable state, unlike the conventional advance / retract guide section (see Figure 8) that allows the cantilevered protruding portion of a slide shaft to slide between the upper and lower slide roller pins, this effectively avoids the tendency for the formwork to become eccentric or develop an offset load due to fatigue caused by repeated use, resulting in lateral shaking (wandering) or rattling.By moving the end plate 14 in a precise and stable state over a long period of time, it is possible to repeatedly form high-quality hexagonal segments many times.

[0049] Furthermore, according to this embodiment, the advance / retract operating unit 25 of the end plate advance / retract mechanism 20 is provided below the apex of the V-shaped portion formed by the end plate 14a, and the advance / retract guide units 23 are arranged symmetrically in a pair on both sides of the advance / retract operating unit 25, and are each provided below the hypotenuse on both sides of the V-shaped portion formed by the end plate 14a. This makes it possible to retreat the V-shaped portion, that is, the end plate 14a, in a more balanced manner, and by advancing and retreating the end plate unit 14 in a more precise and stable manner, it becomes possible to continue to form high-quality hexagonal segments.

[0050] The present invention is not limited to the above embodiment, and various modifications are possible. For example, the advancing / retracting operation unit of the end plate advancing / retracting mechanism does not necessarily have to be provided below the apex of the V-shaped portion of the end plate, and the advancing / retracting guide units of the end plate advancing / retracting mechanism do not necessarily have to be provided in a pair symmetrically arranged. [Explanation of symbols]

[0051] 10 Formwork for manufacturing hexagonal segments 11 Bottom plate part 11a Bottom plate (curved part) 11b Fixed rib plate 12 Face side plate 12a Side panel (curved part) 12b Face side support wall 13 Side plate on the well mouth side 13a Side panel (curved part) 13b Support wall on the wellhead side 14 End plate part 14a End plate (V-shaped part) 14b End plate support wall 14e Support stand 20 End plate advance / retreat mechanism 21 Slide guide shaft 22 Bearings 22a External cylinder 23 Advance / retreat guide section 25 Advance / retract operation section 25a Advance / retract bolt 30 Base 32 Side plate advancement / retraction mechanism 33 Shaft insertion member 34 Side plate slide shaft 35 Advance / retreat operation section 36 Support bracket 40 hexagonal segments 41 Axial direction joint surface on face side 42 Axial joint surface on wellhead side 43 Face side oblique joint surface 44 Diagonal joint surface on the entrance side 45 V-shaped circumferential joint surface

Claims

1. A form for manufacturing a hexagonal segment for forming, by pouring and hardening concrete, a hexagonal segment having a face-side axial joint surface and a wellhead-side axial joint surface, and a pair of V-shaped circumferential joint surfaces consisting of a face-side oblique joint surface and a wellhead-side oblique joint surface arranged in a V shape so as to connect both ends of the pair of axial joint surfaces, the form comprising: the hexagonal segment; a face-side side plate portion having a curved portion along the face-side axial joint surface, and a wellhead-side side plate portion having a curved portion along the wellhead-side axial joint surface, the face-side side plate portion being arranged upright on both side edges of the bottom plate portion; a pair of end plate portions having V-shaped portions along the V-shaped circumferential joint surface, the end plate portions being arranged upright on both end edges of the bottom plate portion; and a base portion supporting the bottom plate portion, side plate portions, and end plate portions as a whole from below, the face side side plate portion and the wellhead side side plate portion are arranged so as to be movable toward and away from each other via a side plate advancing / retracting mechanism supported by the base portion, and the pair of end plate portions are arranged so as to be movable toward and away from the bottom plate portion via an end plate advancing / retracting mechanism supported by the base portion, the end plate advancing / retracting mechanism includes an advancing / retracting guide section including a slide guide shaft extending linearly in the advancing / retracting direction of the end plate section, and a bearing fixed to the end plate section and slidably disposed along the slide guide shaft, and an advancing / retracting operation section for advancing and retracting the pair of end plate sections, the slide guide shaft of the advance / retreat guide portion is attached in a state in which one end is fixed to the bottom plate portion and the other end is fixed to the base portion, When the bearing slides along the slide guide shaft, the end plate portion advances and retreats in a direction approaching and separating from the bottom plate portion, The slide guide shaft of the advance / retract guide portion is a columnar or cylindrical shaft member. The formwork for manufacturing hexagonal segments is such that the bearings are cylindrical rolling bearings.

2. A formwork for manufacturing hexagonal segments as described in claim 1, wherein the advance / retract operating portion of the end plate advance / retract mechanism is provided in the lower part of the apex of the V-shaped portion of the end plate portion, and the advance / retract guide portions of the end plate advance / retract mechanism are symmetrically arranged in a pair on both sides of the advance / retract operating portion, and are each provided in the lower part of the hypotenuse portions on both sides of the V-shaped portion of the end plate portion.

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