Form structure, fixing jig, and construction method of dam body

Abstract

To provide a form structure, fixing jigs, and a construction method of a dam body allowing concrete to be densely installed as reducing inclusions.SOLUTION: A form structure 1 for concrete installation mainly comprises: first form members 2a, 2b and a second form member 3 continuously erected; water cut-off plates 4a, 4b having flexibility and sandwiched between erected end parts of the first form members 2a, 2b and the second form member 3 so as to be perpendicular to a continuous direction; and a fixing jig 21 relatively fixing positions of the first form members 2a, 2b and the second form member 3. The fixing jig 21 comprises: first fixing parts 22a, 22b detachably fixed on the first form members 2a, 2b; a second fixing part 23 detachably fixed on the second form member 3; and a connection part 24 connecting the first fixing parts 22a, 22b, and the second fixing part 23 while bypassing the water cut-off plate 4a, 4b.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a formwork structure, a fixing jig, and a method for constructing a dam embankment, and in particular to a formwork structure (a structure installed at a joint location upstream of a dam and acting as a joint plate) using a formwork for pouring concrete, a fixing jig, and a method for constructing a dam embankment. [Background technology]

[0002] Dams are constructed to cross rivers or valleys or to surround depressions for purposes such as hydroelectric power generation, flood control, irrigation, forestry conservation, and erosion control. When pouring concrete for dam construction, formwork (formwork structures) is installed as joint plates at the concrete joints.

[0003] FIG. 6 is a diagram showing a conventional form structure, and FIG. 7 is an enlarged view showing the structure around the waterstop of the form structure shown in FIG.

[0004] Referring to these figures, a conventional formwork structure 71 used when pouring concrete on the upstream side of a dam is configured by plate-like formwork members (first formwork members 72a, 72b and second formwork member 73) made of steel plates arranged upright in a continuous manner in the upstream and downstream directions, with two flexible waterstops 74a, 74b installed at a distance between the first formwork member 72a and the second formwork member 73, and between the second formwork member 73 and the first formwork member 72a. Furthermore, to resist the pouring pressure when pouring concrete, the first formwork members 72a, 72b are supported by separator reinforcing bars 75a, 75d connected to the concrete floor surface 80, and similarly, separator reinforcing bars 75b, 75c are installed on the second formwork member 73 located between the waterstops 74a, 74b. Furthermore, since the waterstops 74a, 74b are flexible, in order to maintain their posture, posture maintaining jigs 76a, 76b may be attached to the first formwork members 72a, 72b or the second formwork member 73. Concrete is poured using the formwork structure 71 configured in this way as a formwork.

[0005] In a related matter, Patent Document 1 discloses a separator reinforcement having a watertight property by combining a reaction force receiving projection, a packing ring, and a tightening nut at the end of the separator reinforcement. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Utility Model Application Publication No. 53-518 Summary of the Invention [Problem to be solved by the invention]

[0007] In the conventional formwork structure 71 described above, the most important thing is to stop water from leaking around the waterstop plates 74a, 74b, but the distance between these waterstop plates 74a, 74b is narrow at about 50 cm, and two separator bars 75b, 75c are placed in between them. In addition, posture-maintaining jigs 76a, 76b are attached to the waterstop plates 74a, 74b themselves. Therefore, it is possible that inclusions such as the separator bars 75a to 75d and the posture-maintaining jigs 76a, 76b could cause water to flow through or hinder vibration by the vibrator, resulting in insufficient compaction.

[0008] Even in Patent Document 1, the separator reinforcement itself is provided with water blocking measures, which are insufficient as a measure against water paths that may occur due to inclusions or against insufficient vibration.

[0009] Therefore, there was a need for a technology that could prevent the occurrence of water paths due to inclusions around the waterstop and enable the pouring of dense concrete.

[0010] The present invention has been made to solve the above-mentioned problems, and aims to provide a formwork structure, a fixing jig, and a method for constructing a dam body that can reduce inclusions and allow dense concrete to be poured. [Means for solving the problem]

[0011] In order to achieve the above-mentioned object, the invention described in claim 1 is a formwork structure for pouring concrete, which is composed of plate-shaped formwork members arranged in succession, and which comprises first and second formwork members arranged in succession, a flexible waterstop plate that is sandwiched between the standing ends of the first and second formwork members so as to cross the direction of their continuity, and a fixing jig that fixes the positions of the first and second formwork members relative to each other, and the fixing jig comprises a first fixing portion that is removably fixed to the first formwork member, a second fixing portion that is removably fixed to the second formwork member, and a connecting portion that connects the first fixing portion and the second fixing portion while bypassing the waterstop plate.

[0012] The invention described in claim 2 is the same as the invention described in claim 1, in which the connecting portion comprises a first extension portion connected to the first fixing portion and extending in a direction away from the first formwork member, a second extension portion connected to the second fixing portion and extending in a direction away from the second formwork member, and a bridging portion bridging the first extension portion and the second extension portion.

[0013] The invention described in claim 3 is configured as the invention described in claim 2, wherein the extension lengths of the first extension portion and the second extension portion correspond to the crossing extension length of the waterstop, and the bridging portion contacts the end of the waterstop to maintain the posture of the waterstop.

[0014] The invention described in claim 4 is a fixing jig for fixing plate-shaped formwork members that constitute a formwork for pouring concrete, and comprises a first fixing portion that is removably fixed to a first formwork member that is erected, a second fixing portion that is removably fixed to a second formwork member that is erected continuous with the first formwork member, a first extension portion that is connected to the first fixing portion and extends in a direction away from the first formwork member, a second extension portion that is connected to the second fixing portion and extends in a direction away from the second formwork member, and a bridging portion that bridges the first extension portion and the second extension portion.

[0015] The invention of claim 5 is a method for constructing a dam body using formwork for pouring concrete, comprising the steps of: successively erecting plate-like lower first and second formwork members with a flexible waterstop sandwiched between them; pouring concrete so that the upper portions of the lower first and second formwork members are exposed; connecting an upper first formwork member above the lower first formwork member exposed from the concrete; and connecting an upper second formwork member above the lower second formwork member exposed from the concrete. the first fixing part of the fixing jig to the top of the upper first formwork member and the second fixing part to the top of the upper second formwork member, and a connecting part that connects the first fixing part and the second fixing part while bypassing the water stop; and the second fixing part of the fixing jig to the top of the upper first formwork member and the top of the upper second formwork member to form a formwork; and the concrete pouring process in the formwork up to below the fixing jig.

[0016] The invention described in claim 6 is the same as the invention described in claim 5, and includes the steps of removing the fixing jig from the upper first formwork member and the upper second formwork member after pouring the concrete, connecting an additional first formwork member above the upper first formwork member and connecting an additional second formwork member above the upper second formwork member, and fixing the first fixing part of the fixing jig to the top of the additional first formwork member and fixing the second fixing part to the top of the additional second formwork member to form an additional formwork. [Effects of the Invention]

[0017] According to the present invention, the number of separator reinforcement bars supporting the formwork members can be reduced, thereby reducing the risk of water paths occurring due to the presence of separator reinforcement bars and insufficient compaction of the concrete, and allowing dense concrete to be poured around the waterstop plate. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a diagram showing a formwork structure according to a first embodiment of the present invention; [Figure 2]FIG. 2 is an enlarged view of a fixing jig used in the formwork structure shown in FIG. [Figure 3] FIG. 2 is an enlarged view showing the structure around the waterstop of the formwork structure shown in FIG. [Figure 4] FIG. 2 is a schematic diagram showing the planar structure of the formwork structure shown in FIG. [Figure 5] FIG. 10 is a schematic view showing another embodiment of the fixing jig of the present invention. [Figure 6] FIG. 1 is a diagram showing a conventional formwork structure. [Figure 7] FIG. 7 is an enlarged view showing the structure around the waterstop of the formwork structure shown in FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0019] FIG. 1 is a diagram showing a formwork structure according to a first embodiment of the present invention, FIG. 2 is an enlarged view of a fixing jig used in the formwork structure shown in FIG. 1, FIG. 3 is an enlarged view showing the structure around the waterstop plate of the formwork structure shown in FIG. 1, and FIG. 4 is a schematic diagram showing the plan view structure of the formwork structure shown in FIG. 1.

[0020] 1 is the upstream side and the left side is the downstream side in this embodiment, but the direction in which the formwork members continue (sometimes referred to as the "continuous direction" in this invention) can be changed depending on the situation in which the present invention is applied. For example, the formwork members may be continuous in the direction connecting the left bank and the right bank.

[0021] Referring to these figures, formwork structure 1, which is used when pouring concrete on the upstream side of a dam and is installed at concrete joints (joint locations) to act as a joint plate, is composed of a series of plate-like formwork members (first formwork members 2a, 2b and second formwork member 3) made of steel plates arranged upright. Specifically, formwork structure 1 is mainly composed of first formwork members 2a, 2b and second formwork member 3 arranged upright, flexible waterstop plates 4a, 4b sandwiched between the upright ends of first formwork members 2a, 2b and second formwork member 3 so as to be perpendicular to the direction of continuity, and fixing jig 21 which fixes the positions of first formwork members 2a, 2b and second formwork member 3 relative to one another.

[0022] The first formwork member 2a is composed of a lower first formwork member 8a, most of which is already embedded in the concrete floor surface 20, with only its upper part exposed, and an upper first formwork member 7a, which is connected above the lower first formwork member 8a via a flange 11a. Similarly, the first formwork member 2b is composed of a lower first formwork member 8b and an upper first formwork member 7b, which is connected above the lower first formwork member 8b via a flange 11b. Similarly, the second formwork member 3 is composed of a lower second formwork member 10 and an upper second formwork member 9, which is connected above the lower first formwork member 8b via a flange 11c.

[0023] The width in the continuous direction of the first formwork member 2a is 1000 mm, and the width in the continuous direction of the first formwork member 2b is 500 mm. The width in the continuous direction of the second formwork member 3 is also 500 mm. The first formwork members 2a and 2b are supported by a plurality of separator bars 5a and 5b that connect to the concrete floor surface 80.

[0024] The flanges 11a to 11c are provided in advance so as to protrude from the upper and lower ends of each form member (2a, 2b, 3), and are fixed with fasteners such as bolts to connect, for example, the lower first form member 8a and the upper first form member 7a. The flanges 11a to 11c may also be used to fix the first fixing portions 22a, 22b and the second fixing portion 23 of the fixing jig 21.

[0025] The waterstop plates 4a, 4b are made of polyvinyl chloride and are flexible, have grooves formed in the vertical direction, and are sandwiched between the first formwork member 2a and the second formwork member 3, and between the second formwork member 3 and the first formwork member 2b, thereby enhancing the watertightness of the formwork structure 1.

[0026] 1 and 2, fixing jig 21 is made up of first fixing parts 22a, 22b that are detachably fixed to first formwork members 2a, 2b (upper first formwork members 7a, 7b), a second fixing part 23 that is detachably fixed to second formwork member 3 (upper second formwork member 9), and a connecting part 24 that connects first fixing parts 22a, 22b and second fixing part 23 while bypassing waterstops 4a, 4b. Note that Figure 4 shows a schematic structure of fixing jig 21.

[0027] Each of the first fixing portions 22a, 22b is fixed to each of the first formwork members 2a, 2b with fixing devices such as bolts. Similarly, the second fixing portion 23 is fixed to the second formwork member 3 with fixing devices.

[0028] 4, the connecting portions 24 are provided so as to contact the protruding ends of the waterstops 4a, 4b. The effect of this will be described later. Note that the connecting portions 24 bypassing the waterstops 4a, 4b includes not only a mode in which they contact the protruding ends of the waterstops 4a, 4b as in this embodiment, but also a mode in which they are connected at a sufficient distance so as not to contact each other, or conversely, a mode in which they are connected so as to be compressed in the direction of the formwork members to an extent that the waterstop effect of the waterstops 4a, 4b is not lost.

[0029] By using such a fixing jig 21, the first formwork members 2a, 2b and the second formwork member 3 can be connected and their positions fixed relative to one another. As shown in Fig. 3, in this embodiment, it is not necessary to provide separator reinforcing bars 5 for the second formwork member 3. In this way, the number of separator reinforcing bars 5 supporting the formwork members can be reduced, which reduces the risk of water paths being formed due to the presence of separator reinforcing bars 5 or of inclusions between the waterstops 4a, 4b hindering the penetration of the vibrator and resulting in insufficient compaction of the concrete, and allows for dense concrete to be poured around the waterstops 4a, 4b.

[0030] In addition, the connecting portion 24 is composed of first extension portions 25a, 25b connected to the first fixing portions 22a, 22b and extending in a direction away from the first formwork members 2a, 2b (a direction perpendicular to the continuous direction), a second extension portion 26 connected to the second fixing portion 23 and extending in a direction away from the second formwork member 3, and a bridging portion 27 bridging the first extension portions 25a, 25b and the second extension portion 26.

[0031] By configuring it in this manner, the formwork members can be connected to each other by the first extension portions 25a, 25b and second extension portion 26 of the connecting portion 24 and the bridging portion 27, while bypassing the waterstop plates 4a, 4b, thereby improving the stability of the fixation by the connecting portion 24.

[0032] In addition, in this embodiment, the extension lengths (lengths in a direction perpendicular to the continuous direction) of the first extension portions 25a, 25b and the second extension portion 26 are approximately the same corresponding to the intersecting extension lengths (lengths in a direction perpendicular to the continuous direction, and lengths protruding from the formwork members) of the waterstops 4a, 4b, and the bridging portion 27 contacts the ends (protruding ends) of the waterstops 4a, 4b to maintain the posture of the waterstops 4a, 4b.

[0033] By configuring in this manner, the number of posture-maintaining jigs that maintain the posture of the waterstops 4a and 4b can be further reduced, which further reduces the risk of water paths being created by inclusions and insufficient compaction of the concrete, allowing for more dense concrete to be poured around the waterstops 4a and 4b.

[0034] Next, a method for constructing a dam body according to the present invention will be described.

[0035] The method for constructing a dam embankment of the present invention is a method for constructing a dam embankment using formwork for pouring concrete, and first involves a process of successively erecting plate-shaped lower first formwork members 8a, 8b and lower second formwork member 10 while sandwiching flexible waterstop plates 4a, 4b between them.

[0036] Next, a fixing jig 21 is prepared in advance, which includes first fixing portions 22a, 22b that are removably fixed to the lower first formwork members 8a, 8b, a second fixing portion 23 that is removably fixed to the lower second formwork member 10, and a connecting portion 24 that connects the first fixing portions 22a, 22b and the second fixing portion 23 while bypassing the waterstops 4a, 4b, and a process is carried out in which the first fixing portions 22a, 22b of the fixing jig 21 are fixed to the upper part (upper end) of the lower first formwork members 8a, 8b and the second fixing portion 23 is fixed to the upper part (upper end) of the lower second formwork member 10 to construct the formwork.

[0037] Then, concrete is poured into the formwork up to below the fixed jig 21 (to a height just before the concrete touches the fixed jig 21 and at a height where the tops of the lower first formwork members 8a, 8b and the top of the lower second formwork member 10 are exposed), and vibration is applied using a vibrator, compaction is performed, etc.

[0038] Next, the process of removing the fixing jig 21 from the lower first formwork members 8a, 8b and the lower second formwork member 10 is carried out.

[0039] In this way, concrete is poured so as to expose the upper parts of the lower first formwork members 8a, 8b and the lower second formwork member 10. Note that if concrete can be poured so that the upper parts of the lower first formwork members 8a, 8b and the lower second formwork member 10 are exposed to the extent that they can be connected to at least the upper first formwork members 7a, 7b and the upper second formwork member 9, then it is not necessarily necessary to use the fixing jig 21 at this stage.

[0040] Next, a process is carried out in which the upper first formwork members 7a, 7b are connected above the lower first formwork members 8a, 8b exposed from the concrete, and the upper second formwork member 9 is connected above the lower second formwork member 10 exposed from the concrete.

[0041] Next, the first fixing portions 22a, 22b of fixing jig 21 are fixed to the tops (upper ends) of upper first formwork members 7a, 7b, and the second fixing portion 23 is fixed to the top (upper end) of upper second formwork member 9, thereby constructing the formwork (formwork structure 1). Note that since lower first formwork member 8a and upper first formwork member 7a are basically the same shape, first fixing portion 22a of fixing jig 21 can also be detachably fixed to upper first formwork member 7a. The same relationship applies to lower first formwork member 8b and upper first formwork member 7b, lower second formwork member 10 and upper second formwork member 9, and the first fixing portion 22b and second fixing portion 23 relative to these.

[0042] Then, a process of pouring concrete into the formwork structure 1 up to below the fixing jig 21 (to a height just before the concrete touches the fixing jig 21) is carried out, followed by vibration with a vibrator, compaction, and the like.

[0043] By doing this, the number of separator reinforcement bars 5 that support the formwork members can be reduced, which reduces the risk of water paths occurring or insufficient concrete compaction due to the separator reinforcement bars 5 being interposed between the waterstops 4a and 4b, and allows dense concrete to be poured around the waterstops 4a and 4b.

[0044] Furthermore, if a required height for the dam embankment is required, after pouring the concrete, the steps are taken to remove the fixing jig 21 from the upper first formwork members 7a, 7b and the upper second formwork member 9, and to connect an additional first formwork member (not shown) above the upper first formwork members 7a, 7b, and to connect an additional second formwork member (not shown) above the upper second formwork member 9.

[0045] Then, the first fixing portions 22a, 22b of the fixing jig 21 are fixed to the top of the first additional formwork member, and the second fixing portion 23 is fixed to the top of the second additional formwork member, thereby forming an additional formwork.

[0046] In this way, by removing the fixing jig 21 after pouring concrete, the formwork members can be successively extended upward and installed.

[0047] FIG. 5 is a schematic diagram showing another embodiment of the fixing jig of the present invention.

[0048] The fixing jigs according to these other embodiments have basically the same structure as the fixing jig according to the first embodiment described above, so the following description will focus on the differences.

[0049] Referring to (1), the fixing jig 31 is composed of a first fixing portion 32 and a second fixing portion 33, each of which is made of a rod-shaped steel material, and a connecting portion 34 that connects the first fixing portion 32 and the second fixing portion 33 while bypassing them. The connecting portion 34 is also composed of a first extending portion 35 that is connected to and extends from the first fixing portion 32, a second extending portion 36 that is connected to and extends from the second fixing portion 33, and a bridging portion 37 that bridges between the first extending portion 35 and the second extending portion 36.

[0050] That is, the fixing jig 31 may be any one that can fix the relative positions of two formwork members (a first formwork member and a second formwork member). When three formwork members (two first formwork members and one second formwork member) are provided as in the first embodiment of the present invention, two of these fixing jigs 31 may be used to fix adjacent formwork members to each other.

[0051] Referring to (2), the fixing jig 40 has four fixing portions 41a to 41d. The structure of each of the fixing portions 41a to 41d is similar to that of the first fixing portions 22a and 22b and the second fixing portion 23 of the fixing jig 21 described above. Any of the four fixing portions 41a to 41d can function as a first fixing portion that is detachably fixed to a first formwork member (not shown), and any can function as a second fixing portion that is detachably fixed to a second formwork member (not shown). The same applies to the four extending portions 42a to 42d.

[0052] Referring to (3), in the fixing jig 45, the first extending portion 49a is composed of a rod-shaped steel material extending perpendicular to the first fixing portion 46a (the position of the first formwork member when installed) and a rod-shaped steel material extending diagonally therefrom so as to be spaced apart from the first fixing portion 46a. In other words, the first extending portion 49a is composed of two rod-shaped steel materials connected to one end of the bridging portion 51, and is configured so that the first extending portion 49a and the first fixing portion 46a, when combined, form a triangular shape in a plan view. The same is true for the first extending portion 49b and the first fixing portion 46b. The second extending portion 50 and the second fixing portion 47, when combined, form a quadrangular shape in a plan view. In this way, the planar shape formed by combining the fixing portion and the extending portion may be a mixture of a triangular shape and a quadrangular shape, which may improve stability and usability. The planar shape formed by the fixing portion and the extending portion may also form another shape.

[0053] Referring to (4), in the fixing jig 54, the first extending portions 55a, 55b and the second extending portion 56 are each made of a single bar-shaped steel material. As such, the shape and material of each of the first extending portion and the second extending portion are not limited as long as they extend away from the first fixed portion and the second fixed portion, respectively.

[0054] Referring to (5), in the fixing jig 58, the first extending portion 59 is configured to include a support rod 62a connected obliquely to the bridging portion 61. Similarly, the second extending portion 60 is configured to include a support rod 62b connected obliquely to the bridging portion 61. The support rods 62a and 62b are connected to the same location on the bridging portion 61, improving the stability of the fixing of the formwork members to each other by the fixing jig 58. Furthermore, a waterstop (not shown) may be sandwiched between the support rods 62a and 62b to improve the function of maintaining the position of the waterstop.

[0055] Referring to (6), in the fixing jig 64, the bridging portion 65 has an engaging portion 66 for engaging with a waterstop (not shown) to maintain the position of the waterstop. Such an addition to the bridging portion 65 is also included in the mode of contacting the end of the waterstop.

[0056] In the present invention, the first and second formwork members refer to two adjacent formwork members sandwiching a waterstop, one of which is the first formwork member and the other the second formwork member, and they may have the same dimensions and shape or different dimensions and shapes. The present invention can also be applied by using the second formwork member 3 in this embodiment as the first formwork member and the first formwork member 2b as the second formwork member.

[0057] Furthermore, in each of the above embodiments, the formwork members are made of a specific material and have a specific shape, but they may be made of other materials and may have other shapes.

[0058] Furthermore, in the above embodiments, the waterstops are made of a specific material and have a specific shape, but they may be made of other materials or have other shapes. Also, while the waterstops are sandwiched between adjacent formwork members so that they intersect at right angles, they may intersect.

[0059] Furthermore, in the above embodiments, a formwork structure that is used when pouring concrete in a dam and is embedded as a joint plate for pouring joints (joints) has been described, but the present invention can be similarly applied to any formwork for pouring concrete that is configured by sandwiching a waterstop between formwork members. Furthermore, even when used in a dam, the present invention can be applied to well-known dams such as gravity concrete dams, arch dams, buttress dams, hollow gravity dams, and combine dams.

[0060] Furthermore, in each of the above embodiments, flanges are used to connect the first and second formwork members vertically, but flanges do not have to be used. They can be connected by welding, or by attaching steel panels later to span the upper and lower parts and fastening them with bolts.

[0061] Furthermore, in each of the above embodiments, the first fixing portion and the second fixing portion of the fixing jig had a specific configuration, but the shape and fixing method are not limited as long as they can be fixed to the first formwork member and the second formwork member, respectively.

[0062] Furthermore, in each of the above embodiments, the connecting portion of the fixing jig has a first extension portion and a bridging portion, but the shape of the connecting portion and the method of connection are not limited as long as the connection can be made while bypassing the waterstop, for example by connecting in an arch shape.

[0063] Furthermore, in each of the above embodiments, the fixing jig is configured to be flat overall by combining steel rods, but the material and shape are not limited thereto. Furthermore, it is not limited to being flat, and may be varied in height, but it is preferable that the first fixing portion and the second fixing portion are at the same height level so that they can be easily fixed to the formwork members.

[0064] Furthermore, although the fixing jig in each of the above embodiments is used for a formwork structure using specific formwork members and waterstops, the present invention can be similarly applied to formwork of any type. In this case, the fixing jig of the present invention can be said to be a fixing jig for fixing plate-like formwork members that constitute a formwork for pouring concrete, and includes a first fixing part detachably fixed to a first formwork member that is installed upright, a second fixing part detachably fixed to a second formwork member that is installed upright and continuous with the first formwork member, a first extending part connected to the first fixing part and extending in a direction away from the first formwork member, a second extending part connected to the second fixing part and extending in a direction away from the second formwork member, and a bridging part connecting the first extending part and the second extending part. By configuring it in this way, when a waterstop is sandwiched between formwork members and installed, the fixing jig can be used to connect the formwork members while bypassing the waterstop, thereby making it possible to fix the formwork members together while reducing the risk of adversely affecting the installation of the waterstop.

[0065] Furthermore, although the dam body is constructed in a specific order in each of the above-described embodiments, the order is not limited thereto. For example, the steps of preparing each component, such as formwork members, waterstops, and fixing jigs, may be performed in any order.

[0066] Furthermore, in each of the above embodiments, the formwork members are further connected upward, but they may be completed without being connected upward.

[0067] Furthermore, in each of the above embodiments, a form structure composed of three form members (two first form members and one second form member), two waterstops, and one fixing jig has been described, but the present invention can be similarly applied to any form structure composed of at least two form members (a first form member and a second form member), one waterstop, and one fixing jig. In this case, too, the number of separator rebars around the waterstops can be reduced, reducing the risk of water paths occurring or insufficient concrete compaction due to the presence of separator rebars, and allowing for dense concrete to be poured around the waterstops. [Explanation of symbols]

[0068] 1...Formwork structure 2...First formwork member 3...Second formwork member 4...Waterstop 7...Upper first formwork member 8...Lower first formwork member 9...Upper second formwork member 10...Lower second formwork member 21, 31, 40, 45, 54, 58, 64...Fixed fixture 22, 32, 46...1st fixed part 23, 33, 47...Second fixed part 24, 34...Connection part 25, 35, 49, 55, 59...1st extension part 26, 36, 50, 56, 60...Second extension part 27, 37, 51, 61, 65...Bridge part 41...Fixed part 42...Extending part In addition, the same reference numerals in each drawing indicate the same or corresponding parts.

Claims

1. A formwork structure for pouring concrete, which is formed by continuously erecting plate-shaped formwork members, a first formwork member and a second formwork member that are erected successively; a flexible waterstop that is sandwiched between the upright ends of the first formwork member and the second formwork member so as to intersect with the continuous direction; a fixing jig that fixes the positions of the first formwork member and the second formwork member relative to each other, The fixing jig is a first fixing portion that is detachably fixed to the first formwork member; a second fixing portion that is detachably fixed to the second formwork member; a connecting portion that connects the first fixing portion and the second fixing portion while bypassing the waterstop.

2. The connecting portion is a first extending portion connected to the first fixing portion and extending in a direction away from the first formwork member; a second extending portion connected to the second fixing portion and extending in a direction away from the second formwork member; The form structure according to claim 1 , further comprising a bridging portion that bridges the first extension portion and the second extension portion.

3. The first extension portion and the second extension portion have extension lengths corresponding to the intersecting extension lengths of the waterstop, The form structure according to claim 2 , wherein the bridging portion contacts an end of the waterstop to maintain the position of the waterstop.

4. A fixing jig for fixing plate-shaped formwork members that constitute a formwork for pouring concrete, a first fixing portion that is detachably fixed to a first formwork member that is erected; a second fixing portion that is detachably fixed to a second formwork member that is erected continuously from the first formwork member; a first extending portion connected to the first fixing portion and extending in a direction away from the first formwork member; a second extending portion connected to the second fixing portion and extending in a direction away from the second formwork member; a bridging portion that bridges the first extending portion and the second extending portion.

5. A method for constructing a dam body using a formwork for pouring concrete, comprising: a step of erecting plate-like lower first formwork members and lower second formwork members in succession with a flexible waterstop plate sandwiched therebetween, and pouring concrete so that upper portions of the lower first formwork members and the lower second formwork members are exposed; a step of connecting an upper first formwork member to an upper portion of the lower first formwork member exposed from the concrete, and connecting an upper second formwork member to an upper portion of the lower second formwork member exposed from the concrete; a step of preparing in advance a fixing jig having a first fixing part detachably fixed to the upper first formwork member, a second fixing part detachably fixed to the upper second formwork member, and a connecting part that connects the first fixing part and the second fixing part while bypassing the waterstop, and fixing the first fixing part of the fixing jig to the upper part of the upper first formwork member and fixing the second fixing part to the upper part of the upper second formwork member to form a formwork; and pouring concrete into the formwork up to below the fixing jig.

6. removing the fixing jig from the upper first formwork member and the upper second formwork member after pouring the concrete; a step of connecting an additional first formwork member above the upper first formwork member and connecting an additional second formwork member above the upper second formwork member; 6. A method for constructing a dam embankment as described in claim 5, further comprising a step of fixing the first fixing portion of the fixing jig to the top of the additional first formwork member and fixing the second fixing portion to the top of the additional second formwork member to form an additional formwork.

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