Joint device and joint structure

Abstract

To provide a joint device and a joint structure which can be integrally molded as a casting, and can achieve both weight reduction and securing of anchor force.SOLUTION: A joint device embedded in a precast member that is a segment or a floor slab and used to connect a pair of the precast members to each other, the joint device comprising: a connecting member configured to connect the pair of joint devices to each other in a state in which the pair of joint devices are butted against each other; and an anchor member anchored in the precast member and configured to prevent the joint device from being pulled out of the precast member, the anchor member has a shape that gradually increases in diameter in a width direction of the segment or the floor slab and gradually decreases in diameter in a thickness direction of the segment or the floor slab from one end portion, which is a coupling portion with the coupling member, toward the other end portion.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a joint device and a joint structure used to connect members used in constructing a structure, for example, to connect precast concrete members. [Background technology]

[0002] In modern cities, when constructing structures such as buildings and various underground structures, a known technique is to construct columns and beams by transporting prefabricated concrete members to the construction site and assembling them together or to existing members. In addition, when constructing tunnels, a known construction method is to connect multiple segments adjacent to each other in the circumferential direction.

[0003] Various connecting means are used to connect various components together. For example, Patent Document 1 discloses a joint device and joint structure used to connect precast concrete components together. Furthermore, Patent Document 2 discloses a connecting metal fitting for connecting concrete segments that form the inner wall of a tunnel. These connecting means can improve productivity, such as by increasing connection strength and reducing costs. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-156027 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-307099 Summary of the Invention [Problem to be solved by the invention]

[0005] Concrete segments (hereinafter simply referred to as segments) primarily used in tunnel construction are components that are sufficiently long in the width direction of the segment (i.e., the tunnel circumferential direction), but not so long in the girder height direction (i.e., the member thickness direction), and are relatively thin. Therefore, when the joint device and joint structure described in Patent Document 1 are applied to segments, the anchor members expand in diameter in the same manner in both the width direction and the girder height direction, making placement difficult. There are directions in which the cone breaking area is not sufficiently secured, and there is a risk that sufficient anchor pull-out strength will not be ensured. Furthermore, because the anchor members expand in diameter from one end to the other, their weight increases, raising concerns about increased costs.

[0006] Furthermore, Patent Document 2 discloses forming the cross-sectional shape of the anchor part into a flat shape, which is suitable for application to segments. In Patent Document 2, the cross-sectional shape of the anchor part is constant in the longitudinal direction, and the anchoring force is ensured by integrally forming ribs on the outer periphery and end parts. However, if a large pull-out force is applied to the anchor part, stress will be concentrated locally on the ribs, which may cause cracks or the like in the segment.

[0007] In view of the above circumstances, an object of the present invention is to provide a joint device and a joint structure that can be integrally molded as a casting and that can achieve both weight reduction and a guaranteed anchoring force. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, according to the present invention, there is provided a coupling device that is embedded in precast members that are segments or deck slabs and is used to connect a pair of the precast members, the coupling device including: a connecting member for connecting the pair of coupling devices when the pair of coupling devices are butt-jointed together; and an anchor member that is fixed inside the precast members and prevents the coupling device from being pulled out of the precast members, wherein the anchor member has a shape that gradually increases in diameter in the width direction of the segment or deck slab and gradually decreases in diameter in the thickness direction as it moves from one end, which is the connecting portion with the connecting member, to the other end.

[0009] In the anchor member, the area of ​​a cross section parallel to the width direction and thickness direction of the segment or the deck slab may be configured to be approximately uniform in the length direction of the anchor member.

[0010] The connecting member and the anchor member may be integrally formed cast or forged members.

[0011] Furthermore, according to the present invention, there is provided a joint structure formed by connecting a pair of the above-described joint devices, characterized in that one joint device has a male member as the connecting member and the other joint device has a female member as the connecting member, and the pair of precast members are connected together by fitting the male member into the female member.

[0012] Furthermore, according to the present invention, there is provided a joint structure formed by connecting a pair of the above-described joint devices, characterized in that each of the pair of joint devices has a female member as the connecting member, and the pair of precast members are connected to each other by butting the pair of female members together and inserting a cotter member as a fitting body. [Effects of the Invention]

[0013] According to the present invention, a joint device and a joint structure are provided which can be integrally molded as a casting and which can achieve both weight reduction and a guaranteed anchoring force. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic illustration of segments used in constructing a tunnel. [Figure 2] FIG. 2 is a schematic explanatory view of a single member of the coupling device. [Figure 3] FIG. 3 is a schematic diagram showing a cross section in FIG. 2. [Figure 4] FIG. 2 is a schematic explanatory diagram (schematic cross-sectional view) of a first connection mode. [Figure 5] FIG. 1 is a schematic explanatory diagram (schematic plan view) of a first connection mode. [Figure 6] FIG. 10 is a schematic explanatory diagram (schematic plan view) of a second connection mode. [Figure 7] FIG. 10 is a schematic explanatory diagram (schematic cross-sectional view) of a second connection mode. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification and the drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description may be omitted.

[0016] When constructing general concrete structures such as buildings and tunnels, construction is carried out by connecting multiple precast concrete members (hereinafter also simply referred to as precast members). Furthermore, in flat structures used to pave large areas such as airport parking areas and taxiways, construction is carried out by joining multiple flat precast members laid on a roadbed. The joint device and joint structure of the present invention can be applied to various such precast members. In this embodiment, the application to segments used mainly in constructing tunnels will be described as an example, and the application to segments as a pair of precast members P (P1, P2) will be described, for example.

[0017] <Segment composition> Figure 1 is a schematic diagram of a segment 1 used in constructing a tunnel as a concrete structure, with (a) being a bird's-eye view and (b) being a top view. As shown in Figure 1, segment 1 is a concrete member that has a roughly rectangular shape when viewed from above, with its long sides 5, 5 extending in the tunnel circumferential direction (X direction). In other words, it is an arc-shaped member with a curvature in the X direction in the figure, and its width direction (Y direction) is the longitudinal direction of the tunnel.

[0018] As shown in Figure 1, at least one connecting portion 10 (here, three portions 10a to 10c) is provided at the longitudinal end (X direction) of each segment 1 for connecting a pair of adjacent segments 1. A joint device (joint device 20, described below) for connecting the segments 1 is embedded inside the segment 1 at the connecting portion 10. A pair of joint devices are arranged facing each other and connected to form a joint structure.

[0019] While segment 1 is a member that has sufficient length in the longitudinal direction (X direction) and width direction (Y direction), it does not have a significant length in the girder height direction (Z direction: thickness direction). Therefore, as mentioned above, with the joint device disclosed in Patent Document 1, there are directions in which the cone breaking area is not sufficiently secured, and there is a risk that sufficient anchor pull-out strength will not be ensured. Furthermore, with the configuration of the anchor with ribs disclosed in Patent Document 2, there is concern that stress will be concentrated locally on the rib, causing cracks and other problems, preventing the joint function from being fully exerted.

[0020] Therefore, the inventors have thoroughly studied the design of a coupling device that ensures anchoring force as a connecting member and suppresses increases in weight and cost even when the member (segment 1 in this case) in which the coupling device is embedded has a direction in which the length is short (the girder height direction in this case), and have devised a coupling device 20 according to the present embodiment described below. The configuration and the like of the coupling device will be described below with reference to the drawings.

[0021] <Configuration of the coupling device according to the embodiment of the present invention> Figure 2 is a schematic explanatory diagram of a single component of a joint device 20 according to an embodiment of the present invention, where (a) is a schematic plan view and (b) is a schematic side view. Figure 3 is a schematic diagram showing the cross sections in Figure 2, where (a) is the AA cross section and (b) is the BB cross section. Note that the precast component P is not shown in Figure 2, and an example of the boundary position between the precast component P and the outside is indicated by a dashed line in the figure.

[0022] 2, the joint device 20 is composed of a connecting member 25 for connecting precast members P (concrete members) to each other, and an anchor member 30 that protrudes from the connecting member 25 toward the interior of the precast members P (concrete members) and is embedded inside the precast members so as to be fixed (anchored) to the precast members. The anchor member 30 includes a rod-shaped main body 31.

[0023] These connecting members 25 and anchor members 30 may be integrally manufactured as cast members or forged members. In the joint device 20, the range embedded in the precast member P includes at least the entire anchor member 30, and a partial range of the connecting member 25 may be embedded so that a part of the connecting member 25 protrudes outside the precast member P.

[0024] The shape of the connecting member 25 is arbitrarily designed. For example, when a pair of joint devices 20 form an insertion-type joint structure, it may be composed of a male member as a fitting and a female member as a fitted body. Alternatively, when a pair of joint devices 20 form a so-called cotter-type joint structure, it may be configured with only a female member as a fitted body and a cotter member, which is a separate member, as a fitting. The configuration of each joint structure will be described later with reference to FIGS. 4 and 5.

[0025] In FIG. 2, as an example of the connecting member 25, a configuration using a male member as a fitting is illustrated. The anchor member 30 is configured to gradually increase in diameter in one radial direction within the cross section from one end 28, which is the connection location with the connecting member 25, toward the other end 29, and to gradually decrease in diameter in the other radial direction.

[0026] For example, as shown in FIG. 3, with respect to one radial direction (Z direction in the figure), it has a configuration in which the diameter length D2a at the other end 29 is shorter than the diameter length D1a at one end 28 (D1a > D2a), and gradually decreases in diameter. Also, with respect to the other radial direction (Y direction in the figure), it has a configuration in which the diameter length D2b at the other end 29 is longer than the diameter length D1b at one end 28 (D1b < D2b), and gradually increases in diameter. The taper angle of the anchor member 30 in the case of decreasing or increasing the diameter is arbitrarily designed, but a design that allows the reaction force against pulling to be sufficiently exerted on the anchor member 30 embedded and fixed inside the precast member P is preferred.

[0027] When anchor members 30 are embedded in precast member P, the radial direction in which the diameter gradually decreases (Z direction in the figure) or the radial direction in which the diameter gradually increases (Y direction in the figure) can be set arbitrarily, but from the standpoint of ensuring a sufficient cone breaking area and ensuring anchor pull-out strength, it is preferable to set the radial direction in which the diameter gradually decreases (Z direction in the figure) as a direction with a relatively small length and the radial direction in which the diameter gradually increases (Y direction in the figure) as a direction with a relatively large length. For example, when applied to segment 1 (see Figure 1) as precast member P, the radial direction in which the diameter gradually decreases (Z direction in the figure) of anchor member 30 as described above is the girder height direction (thickness direction), and the radial direction in which the diameter gradually increases (Y direction in the figure) is the width direction.

[0028] Furthermore, the anchor member 30 is preferably configured so that its cross-sectional area is approximately constant (uniform) at any position in the longitudinal direction. That is, the cross-sectional area of ​​the anchor member 30, as shown in the YZ cross section in FIG. 3, is preferably designed so that it is approximately constant at any position in the longitudinal direction of the anchor member 30. When the same tensile or compressive force is transmitted as a load along the entire length of the anchor member 30, maintaining the cross-sectional area approximately constant is expected to result in the stress obtained by dividing the load by the cross-sectional area being uniform along the longitudinal direction of the anchor member 30. Furthermore, it is preferable to design this cross-sectional area as small as possible to ensure the anchor pull-out strength. With this design, when the anchor member 30 is embedded in the precast member P, the anchor pull-out strength is ensured and the number of components can be minimized, resulting in a lightweight joint device 20.

[0029] <Joint structure according to an embodiment of the present invention> As described above, when an insertion-type joint structure is constructed using a pair of joint devices 20, a male member as the fitting body and a female member as the fitted body may be used, or when a so-called cotter-type joint structure is constructed, it may be constructed using only a female member as the fitted body and a separate cotter member as the fitting body. Below, we will explain the configuration of the joint structure 40 as a connection form when a joint structure 40 is constructed using a pair of joint devices 20 according to an embodiment of the present invention and adjacent precast members are connected to each other.

[0030] (First form of connection) First, as a first connection form, a case where adjacent precast members P1 and P2 are connected using a first coupling device 20a having a male member as a mating body and a second coupling device 20b having a female member as a mated body will be described. Note that common components of the pair of coupling devices 20a and 20b may be illustrated with the same reference numerals.

[0031] 4 and 5 are schematic explanatory diagrams of the first coupling form, with FIG. 4 being a schematic cross-sectional view and FIG. 5 being a schematic plan view. The anchor member 30a of the first coupling device 20a is embedded inside the precast member P1. Here, the connecting member (male member) 25a of the first coupling device 20a is embedded in a state where at least a portion thereof protrudes (is exposed) from the precast member P1. Furthermore, the anchor member 30b of the second coupling device 20b is embedded inside the precast member P2. Here, the connecting member (female member) 25b of the second coupling device 20b is embedded inside the precast member P2.

[0032] As shown in Figures 4 and 5, with precast members P1 and P2 adjacent to each other, connecting members 25a and 25b are butted together, and connecting member (male member) 25a of first coupling device 20a is fitted into connecting member (female member) 25b of second coupling device 20b. Connecting member 25b may have any shape as long as it has a space inside that can fit connecting member 25a. If necessary, a time-hardening material such as mortar or a cover member (not shown) is applied to the joint, completing the connection between precast members P1 and P2.

[0033] (Second form of connection) Next, as a second connection form, a case will be described in which a so-called cotter-type joint structure is formed using a pair of joint devices 20, and adjacent precast members P1 and P2 are connected using a pair of joint devices 20 having the same configuration. Note that while the first connection form described above is mainly used for tunnel segments, the configuration related to the second connection form is mainly used for connecting flat deck slabs.

[0034] 6 and 7 are schematic explanatory diagrams of a second connection form, with FIG. 6 being a schematic plan view and FIG. 7 being a schematic side view. In this connection form, a pair of coupling devices 20c of the same configuration is used. An anchor member 30c of the coupling device 20c is embedded inside the precast member P1. A similar anchor member 30c of the coupling device 20c is also embedded inside the precast member P2. At this time, the coupling members 25c, 25c of each coupling device 20c, 20c are embedded inside the precast members P1, P2, respectively. The coupling members 25c, 25c here are female members that serve as mated bodies.

[0035] As shown in Figures 6 and 7, a pair of connecting members 25c, 25c are butted together while precast members P1 and P2 are adjacent to each other. A cotter member 50, which serves as a fitting body with an H-shaped cross section, is inserted into the fitting space S thus formed, and a bolt 54 is inserted into a bolt hole 53 formed in the cotter member 50 and engaged with the bottom of the connecting member 25c to complete the connection. If necessary, a time-hardening material such as mortar or a cover member (not shown) is applied to the joint portion, completing the connection between precast members P1 and P2. It should be noted that the shape and configuration of the cotter member 50 illustrated here are merely examples, and in the coupling device 20c according to this embodiment, the shape and configuration of the cotter member 50 are arbitrary as long as they suitably connect the pair of connecting members 25c, 25c.

[0036] When precast members P1 and P2 are connected using the configurations related to the first and second connection forms described above, a tensile force acts between adjacent precast members P1 and P2, separating them, and even if a pull-out force is applied to anchor members 30 (30a to 30c), sufficient anchoring force is ensured between the anchor members 30 (30a to 30c) and the surrounding concrete due to the action of the bearing reaction force in addition to the adhesion force.

[0037] In both the first and second connection configurations, the anchor members 30 (30a-30c) are configured so that they gradually increase in diameter in one radial direction within the cross section and gradually decrease in diameter in the other radial direction from one end 28 to the other end 29. For example, the radial direction in which the diameter gradually decreases as described above may be the thickness direction of the precast members P1, P2, and the radial direction in which the diameter gradually increases may be the width direction of the precast members P1, P2. This ensures anchor pull-out strength and minimizes the number of members, thereby reducing the weight of the coupling device 20.

[0038] (Action and effect) According to the joint device 20 of this embodiment and the joint structure 40 constituted by a pair of joint devices 20a, 20b or 20c, 20c, whether the first or second connection form described above is adopted, the anchor members 30 (30a to 30c) are configured so that they gradually increase in diameter in one radial direction within the cross section and gradually decrease in diameter in the other radial direction from one end 28 to the other end 29. This increases the cone breaking area in the desired direction of the precast member P (for example, the width direction of the segment 1), ensuring sufficient anchor pull-out strength, and also reduces the amount of components in other directions (for example, the girder height direction of the segment 1), thereby reducing the weight of the joint device 20.

[0039] The anchor members 30 (30a to 30c) may be configured so that the cross-sectional area at any position in the longitudinal direction is approximately constant. This ensures a more appropriate anchor pull-out strength when the anchor members 30 are embedded in the precast member P, and minimizes the number of members.

[0040] Furthermore, when manufacturing the joint device 20, it is preferable to integrally mold the connecting member 25 and the anchor member 30 as cast or forged members, thereby reducing the number of members and costs.

[0041] While one embodiment of the present invention has been described above, the present invention is not limited to the illustrated embodiment. It is clear that a person skilled in the art can conceive of various modifications and alterations within the scope of the ideas set forth in the claims, and it is understood that these modifications and alterations also fall within the technical scope of the present invention.

[0042] For example, in the above embodiments, a joint structure is constructed by using a male member and a female member as a joint device and fitting them together (see the first connection form), or a joint structure is constructed by using a pair of female members and a cotter member, which is a separate member, as the fitting body (see the second connection form), but the scope of application of the technology of the present invention is not limited to this. In other words, the joint device according to the present invention requires only that the anchor member have a predetermined shape, and the other components can be designed as desired.

[0043] Furthermore, anchor member 30 of the present invention may have any shape as long as it is configured so that the diameter gradually increases in one radial direction within the cross section and gradually decreases in the other radial direction from one end 28 to the other end 29. For example, the cross-sectional shape may be rectangular or elliptical.

[0044] In addition, examples of precast members to which the joint device of the present invention can be applied include segments and deck slabs, but it can be applied to any precast member as long as it has the characteristics of being narrow in the thickness direction and wide in the width direction. [Industrial Applicability]

[0045] The present invention is applicable to a joint device and a joint structure used to connect members used in constructing a structure, for example, to connect precast concrete members. [Explanation of symbols]

[0046] 1...segment 20...Coupling device 25...Connecting member 28...One end (of the anchor member) 29...(Another end of the anchor member) 30...Anchor member 40...Joint structure 50...Cotter member P (P1, P2)...Precast members

Claims

1. A joint device that is embedded in a precast member that is a segment or a deck slab and is used to connect a pair of the precast members, a connecting member for connecting the pair of coupling devices together in a state where the coupling devices are butted against each other; an anchor member fixed to the interior of the precast member to prevent the coupling device from being pulled out of the precast member; A coupling device characterized in that the anchor member has a shape that gradually increases in diameter in the width direction of the segment or the deck slab and gradually decreases in diameter in the thickness direction as it moves from one end, which is the connecting portion with the connecting member, to the other end.

2. 2. The joint device according to claim 1, wherein the cross-sectional area of ​​the anchor member parallel to the width direction and thickness direction of the segment or the deck slab is configured to be approximately uniform in the length direction of the anchor member.

3. 3. A joint device according to claim 1, wherein the connecting member and the anchor member are integrally formed by casting or forging.

4. A joint structure constructed by connecting a pair of the joint devices according to claim 1 or 2, One of the coupling devices has a male member as the connecting member, The other coupling device has a female member as the connecting member, A joint structure characterized in that a pair of the precast members are connected together by fitting the male member into the female member.

5. A joint structure constructed by connecting a pair of the joint devices according to claim 1 or 2, Each of the pair of coupling devices includes a female member as the connecting member, A joint structure characterized in that a pair of the precast members are connected to each other by butting the pair of female members together and inserting a cotter member as a fitting.

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