Coupling device and coupling method

Abstract

To provide a connecting device and connecting method that can efficiently connect concrete structures even if the embedded members provided at the ends of the concrete structures are not directly facing each other. [Solution] The connecting device includes a rod-shaped shaft portion 22, a connecting member 21 including a first engaging portion 23 provided at one end of the shaft portion 22 and extending relative to the shaft portion 22, and a second engaging portion 24 provided at the other end of the shaft portion 22 and extending relative to the shaft portion 22, a fixing portion 25 embedded in a concrete structure, and an embedded member 20 including a housing portion 26 exposed at the end of the concrete structure and capable of accommodating the first engaging portion 23 or the second engaging portion 24 and a part of the shaft portion 22. The first engaging portion 23 or the second engaging portion 24 or both are connected to the shaft portion 22 so as to be movable in the longitudinal direction of the shaft portion 22, and the respective surfaces on which the housing portion 26 engages with the first engaging portion 23 or the second engaging portion 24 are formed in a spherical shape.

Description

Technical Field

[0001] The present invention relates to a connecting device for connecting concrete structures and a connecting method using the connecting device.

Background Art

[0002] As one of the concrete structures, there is a bridge deck slab. In the replacement work of the deck slab, adjacent concrete precast deck slabs for bridges in the bridge axis direction (the longitudinal direction of the bridge) are connected using a joint as a connecting device. Here, the deck slab is a floor that supports the weight of people, vehicles, etc. passing over the bridge, and the precast deck slab is a deck slab preformed in a factory or the like.

[0003] Generally, as a joint for precast deck slabs, a joint using a plurality of loop reinforcing bars arranged on the joint end faces of each precast deck slab is used (see, for example, Patent Document 1). However, in this joint, since the joint space between the precast deck slabs is large (the filling width is wide), it is necessary to place filling concrete.

[0004] Therefore, a joint has been proposed that reduces the filling width and eliminates the placement of filling concrete (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the joint described in Patent Document 2 above has a problem in that if the erected deck slabs are displaced laterally in a direction perpendicular to the bridge axis (perpendicular to the bridge axis), and the embedded metal fittings provided at the ends of each deck slab are not facing each other, it is not possible to insert the fitting metal fitting from above into the embedded metal fitting whose upper side is exposed and fit it in, making it impossible to connect the deck slabs together.

[0007] Additionally, by repositioning the embedded metal fittings at the ends of each deck slab so that they face each other directly, the interlocking alloy can be fitted, but this will increase the time required to connect the deck slabs.

[0008] Therefore, there was a need for a connecting device and a connecting method using the connecting device that could efficiently connect concrete structures even if the embedded members provided at the ends of the concrete structures were not directly facing each other. [Means for solving the problem]

[0009] The present invention has been made in view of the above problems, and is a connecting device for connecting concrete structures together, A connecting member comprising a rod-shaped shaft portion, a first engaging portion provided at one end of the shaft portion and extending relative to the shaft portion, and a second engaging portion provided at the other end of the shaft portion and extending relative to the shaft portion, An embedded member including a fixing portion embedded in a concrete structure and a housing portion exposed at the end of the concrete structure, which can accommodate a first engaging portion or a second engaging portion and a part of the shaft portion. Includes, The first engaging portion, the second engaging portion, or both are connected to the shaft so as to be movable in the longitudinal direction of the shaft. A coupling device is provided in which the surfaces on which the housing portion and the first engaging portion or the second engaging portion engage are formed in a spherical shape. [Effects of the Invention]

[0010] According to the present invention, it is possible to efficiently connect concrete structures even if the embedded members provided at the ends of the concrete structures are not directly facing each other. [Brief explanation of the drawing]

[0011] [Figure 1] A diagram illustrating the replacement work of a concrete floor slab. [Figure 2] A diagram illustrating the procedure for connecting floor slabs using conventional loop reinforcement joints. [Figure 3] A diagram illustrating the width of conventional deck slabs. [Figure 4] A diagram showing an example of precast floor slabs connected using a connecting device. [Figure 5] A diagram showing a first example of the configuration of the buried member and connecting member that constitute the connecting device. [Figure 6] A view of the buried component from the front and the side. [Figure 7] A diagram illustrating the width of the floor slab in which the embedded components are installed. [Figure 8] A diagram showing a second example of the configuration of the buried component. [Figure 9] A diagram showing a second example of the configuration of the connecting member. [Figure 10] This diagram shows how a connecting device is used to connect two floor slabs in the event of lateral displacement between the two slabs. [Figure 11] A flowchart illustrating the procedure for connecting two floor slabs using a coupling device. [Modes for carrying out the invention]

[0012] Concrete structures refer to building support components such as foundations, foundation piles, walls, columns, bases, deck slabs, diagonal braces, roof slabs, and horizontal members, all manufactured from concrete. Here, we will explain using a bridge deck slab as an example. However, concrete structures are not limited to bridge deck slabs.

[0013] A bridge is a structure that crosses rivers, valleys, seas, etc. A bridge is constructed by installing a steel bridge girder on bridge piers, arranging steel bars on the bridge girder, assembling formwork, placing concrete to make a floor slab, and installing accessories on the floor slab. The accessories include parapets, guardrails, paving, etc., which are parts higher than the bridge deck at the side ends of the bridge.

[0014] The floor slab is a part of the floor structure of the bridge, which plays a role in allowing people and vehicles to pass through and maintaining the strength of the entire bridge. The floor slab deteriorates over time due to the passage of people and vehicles, etc. If cracks or the like occur due to aging deterioration, the strength of the bridge cannot be maintained. Therefore, regular maintenance is required. One of the maintenance measures is the replacement work of the floor slab. The replacement work of the floor slab is a construction work of removing the existing floor slab from the bridge girder and installing a new floor slab on the bridge girder.

[0015] In the replacement work of the floor slab, in the method of arranging steel bars, assembling formwork, and placing concrete on site as described above, it is necessary to stop the passage of vehicles, etc. for a long time. Therefore, at present, the replacement work is carried out using precast concrete floor slabs preformed in factories or the like.

[0016] Fig. 1 is a diagram for explaining the replacement work of the floor slab. The replacement work of the floor slab is carried out by removing the existing floor slab from above the bridge girder 11 on the bridge pier 10, installing a precast concrete floor slab (hereinafter referred to as "precast floor slab") 12 as a new floor slab on the bridge girder 11, and joining and integrating the precast floor slabs. Fig. 1 shows the state of installing the precast floor slab 12.

[0017] The existing floor slab is removed from the bridge girder 11 using means for cutting concrete such as a concrete cutter, a concrete breaker, a water jet cutter, etc. On the bridge girder 11, the dowels joined for the purpose of increasing the adhesion to concrete and integrating are exposed as the displacement preventer 13. As the dowels, headed studs, perforated steel plate dowels, block dowels (horseshoe-shaped dowels), etc. are used.

[0018] The precast deck slab 12 is a rectangular, plate-shaped concrete block having a predetermined thickness, and is equipped with joints 14 at both ends in the bridge axis direction for connecting them to each other, and shear prevention holes 15 into which shear prevention devices joined to the bridge girder 11 can be inserted. As the joints 14, loop joints are generally used, for example, in which loop reinforcement bars formed in an annular (loop) shape protrude from both ends of the deck slab.

[0019] The precast deck slabs 12 are installed on the bridge girder 11 such that each shear stopper 13 on the girder 11 is inserted into each shear stopper hole 15. Adjacent precast deck slabs 12 in the bridge axis direction are installed according to the procedure shown in Figure 2. By repeating this process, multiple precast deck slabs 12 are installed in a row in the bridge axis direction. Note that the shear stops 13 are omitted in Figure 2.

[0020] As shown in Figure 2(a), a precast deck slab 12b, suspended by a crane or the like, is lowered onto the precast deck slab 12a, which has already been installed on the upper flange 11a of the bridge girder 11, by shifting it in the direction of the bridge axis (step 1). At this time, the precast deck slab 12b is not resting on the upper flange 11a, but is slightly floating. In addition, each of the multiple protruding loop reinforcements of the adjacent precast deck slab 12b is positioned between the multiple protruding loop reinforcements of the precast deck slab 12a.

[0021] Next, as shown in Figure 2(b), the precast slab 12b is brought closer to the already installed precast slab 12a while it is slightly elevated (step 2). Then, as shown in Figure 2(c), the precast slab 12b is installed on the upper flange 11a, aligning its position and height in the bridge axis direction (step 3). As a result, the multiple loop reinforcements of the precast slab 12a and the multiple loop reinforcements of the precast slab 12b form a space that, when viewed from the side, is straight vertically and arc-shaped horizontally. Multiple auxiliary reinforcements extending perpendicular to the bridge axis are inserted into this space, and concrete is poured into the joint space between the precast slabs 12a and 12b to join and integrate the precast slabs 12a and 12b. At this time, grout material is poured into each shear prevention hole 15, joining and integrating each shear prevention 13 with the precast slabs 12a and 12b.

[0022] Incidentally, the Road Traffic Act limits the width of vehicles traveling on roads to 2500 mm, so the standard width of the precast deck slab 12 is 2500 mm. In precast deck slabs equipped with loop joints, which are commonly used, the loop reinforcement 16 portion protrudes outward, as shown in Figure 3, so the actual precast portion is narrower, with a width of about 1800 to 1900 mm. Furthermore, when installed on the bridge girder 11, the gap between the joints 17 of the precast deck slabs 12 is wide, about 300 mm, so it is necessary to pour cast-in-place concrete to fill the gap. This makes construction time-consuming and labor-intensive.

[0023] Therefore, by using a precast floor slab equipped with a joint that narrows the gap width to about several tens of millimeters as described in Patent Document 2 above, and eliminates the need to pour infill concrete, the time required for construction can be shortened and labor can be reduced. Eliminating the pouring of infill concrete means that it is not necessary to place reinforcing bars such as reinforcing steel on site, set up formwork and pour concrete, and integration can be achieved by injecting grout material alone.

[0024] However, in the joint described in Patent Document 2, if the precast deck slabs to be connected are installed with a lateral displacement in the direction perpendicular to the bridge axis, and the embedded metal fittings provided at the ends of each precast deck slab are not directly facing each other, it is not possible to insert the fitting tool from above into the embedded metal fitting whose upper side is exposed. In this case, it is not possible to connect the precast deck slabs together.

[0025] If the lateral displacement is small, the fitting metal fixture can be pushed in and fitted, but it cannot be fitted correctly, resulting in a decrease in the connecting force between the precast slabs, and the required connecting force cannot be obtained.

[0026] Additionally, the embedded metal fittings at the ends of each precast floor slab can be repositioned so that they face each other directly, but in that case, the process of connecting the precast floor slabs takes time.

[0027] Therefore, to enable efficient connection of concrete structures even when the embedded members provided at the ends of the concrete structures are not directly facing each other, a new connecting device and a connection method using this new connecting device are provided.

[0028] As shown in Figure 4, the connecting device is a joint that includes an embedded member 20 embedded in the precast floor slab 12, with a portion of it exposed at the end of the precast floor slab 12, and a connecting member 21 positioned to connect the exposed portion of the embedded member 20 with the exposed portion of the embedded member 20 of the adjacent precast floor slab 12.

[0029] The connecting member 21 has extended portions at both ends of a long rod-shaped object on one end, and at least one of the extended portions is connected so as to be movable in the longitudinal direction of the rod-shaped object. Part of the embedded member 20 is exposed at the end of the precast floor slab 12, and the exposed portion has a part that can accommodate the extended portion of the connecting member 21 and a part of the rod-shaped object. Therefore, two adjacent precast floor slabs 12 can be connected by placing the precast floor slabs 12 to be connected close to an already installed precast floor slab 12, installing the embedded members 20 facing each other, accommodating the connecting member 21 so as to straddle both embedded members 20 in the respective accommodating portions of the embedded members 20, and moving and tightening the movable extended portion.

[0030] The embedded member 20 and the connecting member 21 will be described in detail with reference to Figure 5. First, the connecting member 21 will be described with reference to Figure 5(a). Figure 5(a) is a diagram showing a first configuration example of the connecting member 21. The connecting member 21 includes a rod-shaped shaft portion 22, a first engaging portion 23 provided at one end of the shaft portion 22 and extending relative to the shaft portion 22, and a second engaging portion 24 provided at the other end of the shaft portion 22 and extending relative to the shaft portion 22. The first engaging portion 23 or the second engaging portion 24 or both are connected to the shaft portion 22 so as to be movable in the longitudinal direction of the shaft portion 22. The shaft portion 22 and the first engaging portion 23 may be formed integrally, or the first engaging portion 23 may be configured to be detachable from the shaft portion 22.

[0031] In the example shown in Figure 5(a), the connecting member 21 has a shaft portion 22 and a first engaging portion 23 integrally formed, and a second engaging portion 24 is configured to be detachable from the shaft portion 22. The shaft portion 22 is a rod-shaped object having a predetermined diameter, and the first engaging portion 23 is cylindrical with a larger diameter than the shaft portion 22, and is integrally formed with the shaft portion 22 at one end of the shaft portion 22. The first engaging portion 23 is not limited to a cylindrical shape, but may also be prism-shaped, as long as it is wider than the shaft portion 22. The shape of the end face of the prism may be triangular, quadrilateral, pentagonal, hexagonal, or a polygon with more than one vertex.

[0032] The other end of the shaft portion 22 is threaded. Therefore, the integrally formed shaft portion 22 and the first engaging portion 23 has a shape similar to that of a bolt.

[0033] The second engaging portion 24 is cylindrical, similar to the first engaging portion 23, and has a hole in the center of its circular end face that penetrates from one end face to the other, with the inner surface of the hole being threaded. Therefore, the second engaging portion 24 has a shape similar to a nut. Thus, the second engaging portion 24 is screwed onto the other end of the shaft portion 22, and is connected so as to be movable in the longitudinal direction of the shaft portion 22 by this screwing.

[0034] The first engaging portion 23 and the second engaging portion 24 have opposing inner surfaces. The inner surface of the first engaging portion 23 is the first engaging surface 23a, and the inner surface of the second engaging portion 24 is the second engaging surface 24a. The first engaging surface 23a and the second engaging surface 24a are not flat surfaces, but are formed in a spherical shape, rising in a mountain-like manner from the circular outer edge toward the central shaft portion 22.

[0035] Figure 5(b) shows a first example of the configuration of the embedded member 20. The embedded member 20 includes a fixing portion 25 embedded in the precast slab 12 and a housing portion 26 exposed at the end of the precast slab 12, which can accommodate the first engaging portion 23 or the second engaging portion 24 and a part of the shaft portion 22.

[0036] The fixing part 25 is a rod-shaped object, and its surface may be smooth, but it is preferable to have recesses or protrusions, as this increases the contact area with the concrete constituting the precast part and improves pull-out resistance. In the example shown in Figure 5(b), the fixing part 25 is an anchoring reinforcement having protrusions (ribs) 25a on its surface. When forming the precast floor slab 12, concrete is poured into the formwork, but the ribs 25a of the anchoring reinforcement can be shaped, numbered, and positioned in a way that does not hinder the flowability of the concrete. In the example shown in Figure 5(b), there are two anchoring reinforcements constituting the fixing part 25. There may be only one anchoring reinforcement, but increasing the number of reinforcements can shorten the length of the anchoring reinforcement. The housing part 26 and the fixing part 25 may be integrally molded by casting, or, for example, an internal thread may be formed in the housing part 26 and a threaded reinforcing bar may be screwed into it.

[0037] The housing portion 26 has a horizontal tip facing the housing portion 26 and a vertical upper surface exposed at the end of the precast floor slab 12, provided by the embedded member 20 of the connecting precast floor slab 12. The housing portion 26 has, when viewed from the insertion direction of the connecting member 21, i.e., from above, an opening at the tip, which is continuous with the opening and has a width into which the shaft portion 22 can be inserted, and a second groove portion 26b which has a wider width than the first groove portion 26a into which the first engaging portion 23 or the second engaging portion 24 can be inserted. The first groove portion 26a shown in Figure 5(b) widens towards the tip, allowing a tool to grip the shaft portion 22 to be inserted, and the shaft portion 22 to be gripped with the tool and rotated in a predetermined direction, thereby screwing the threaded other end of the shaft portion 22 into the second engaging portion 24.

[0038] The receiving section 26, when viewed from above, widens from the first groove 26a towards the second groove 26b, forming a step. The engaging surface 26d of this step, facing into the space of the second groove 26b, is formed in a spherical shape so as to abut and engage with the first engaging surface 23a of the first engaging part 23 or the second engaging surface 24a of the second engaging part 24. Therefore, even if the connecting precast deck slabs 12 are installed with misalignment not only in the vertical direction but also in the vertical direction, the connecting member 21 can be inserted and tightened, and the engaging surface 26d of the step and the first engaging surface 23a of the first engaging part 23 or the second engaging surface 24a of the second engaging part 24 can make surface contact and exert bearing resistance. A construction error of ±5mm to ±15mm in misalignment is permissible.

[0039] The housing portion 26, when viewed from above, has a concave third groove portion 26c that is continuous with the second groove portion 26b. This is to allow the shaft portion 22 to be screwed into the second engagement portion 24. Therefore, when the second engagement portion 24 is housed in the second groove portion 26b and the shaft portion 22 is screwed in, causing the tip of the shaft portion 22 to protrude from the second engagement portion 24, the tip of the shaft portion 22 that protrudes from the second engagement portion 24 will be housed in the third groove portion 26c.

[0040] The housing section 26, together with the housing sections 26 of adjacent precast floor slabs 12, inserts one connecting member 21 to connect two precast floor slabs 12. Therefore, approximately half of the connecting member 21 is inserted and housed in one housing section 26. In other words, approximately half of the shaft portion 22 of the connecting member 21 and either the first engaging portion 23 or the second engaging portion 24 are housed in one housing section 26.

[0041] The accommodating section 26 provided by two adjacent precast floor slabs 12 may be configured to accommodate one connecting member 21, or, as shown in Figure 6, it may be configured to accommodate two connecting members 21 vertically, or it may be configured to accommodate three or more connecting members 21. Figure 6(a) is a view from the tip side of the embedded member 20 exposed on the connecting surface of the precast floor slab 12, and Figure 6(b) is a view from one side thereof.

[0042] The tip of the housing portion 26, which is the tip of the embedded member 20, has an opening 27 that extends vertically downward from the upper surface of the housing portion 26. The opening 27 has a width that allows the shaft portion 22 to be inserted when the connecting member 21 is inserted from the upper side of the housing portion 26. The engagement surface 26d of the housing portion 26 is spherical, so that even if two precast floor slabs 12 are installed with a lateral displacement, the connecting member 21 can be inserted into the housing space formed by the two housing portions 26 so as to straddle the housing portions 26 of the two precast floor slabs, and the engagement surface 23a of the first engagement portion 23 and the engagement surface 24a of the second engagement portion 24 will be in surface contact with the engagement surface 26d of each housing portion 26. With the second engagement portion 24 tightened onto the shaft portion 22 while they are in surface contact, the two can be firmly connected.

[0043] The two sides of the housing section 26, other than the tip and the side on the opposite side (back side) to which the fixing section 25 is connected, are in contact with the concrete constituting the precast section and are embedded in the concrete. These sides can be provided with side ribs 28 that protrude laterally from the sides. In addition to ensuring the strength of the housing section 26, the side ribs 28 have the effect of improving adhesion to the concrete and shear resistance. The shape of the side ribs 28 can be any shape as long as it increases the area of ​​adhesion to the concrete and improves shear resistance.

[0044] Figure 7 illustrates the width of the precast slab 12 in which the embedded member 20 is embedded. Only the tips and top surfaces of the housing portions 26 of the embedded member 20 are exposed at both ends of the precast slab 12, and the tips of the housing portions 26 of the embedded member 20 and the ends of the precast slab 12 are approximately flush. For this reason, while conventional precast slabs 12 with loop joints had a narrow precast portion width of about 1800 to 1900 mm, the precast slab 12 in which this embedded member 20 is embedded can be manufactured with a total width of 2500 mm as the precast portion.

[0045] Figure 8 shows a second example of the configuration of the buried member 20. The configuration of the housing section 26 is the same as that shown in Figures 5(b) and 6, so its explanation is omitted here. In the buried member 20 shown in Figure 8(a), the fixing section 25 is composed of two anchoring bars 30, and the two anchoring bars 30 are connected as plate-like objects by an anchor plate 31. In addition, the cross-section of the anchoring bar 30, when cut perpendicular to its longitudinal direction (the cross-section cut along cutting line AA), is not circular, but elliptical as shown in Figure 8(b). The cross-section of the anchoring bar 30 is elliptical, but it may also be circular or roughly rectangular. Furthermore, at least two of the anchoring bars 30 with elliptical, circular, and roughly rectangular cross-sections may be used in combination. Note that the housing section 26 and the fixing section 25 may be integrally formed by casting, or for example, an internal thread may be formed in the housing section 26 and a threaded reinforcing bar may be screwed into it.

[0046] Each of the two anchoring bars 30 has one end connected to the housing section 26 and the other end connected to the anchor plate 31. The anchor plate 31 is connected to one end face of each of the two anchoring bars 30, and the vertical length and horizontal width of one face of the plate are greater than the combined vertical length and horizontal width of the two anchoring bars 30. Therefore, even if the embedded member 20 tries to pull out towards the exposed front end of the housing section 26, the anchor plate 31 will catch on it, preventing it from coming out. Thus, by providing the anchor plate 31, the embedded member 20 can be firmly anchored by the precast floor slab 12. The cross-section of the anchoring bar 30 is elliptical, but it may also be circular or roughly rectangular. In addition, at least two of the anchoring bars 30 with elliptical, circular, and roughly rectangular cross-sections may be used in combination.

[0047] Furthermore, because the cross-sectional shape of the anchoring reinforcement 30 is elliptical rather than circular, the contact area with the concrete is increased, improving the anchorage with the concrete. The cross-sectional shape of the anchoring reinforcement 30, including the ribs 30a (the convex portion around it), is also elliptical. While the cross-section of the anchoring reinforcement 30 is described as elliptical, it may also be circular or roughly rectangular. Additionally, the anchoring reinforcement 30 may be a combination of at least two of the elliptical, circular, and roughly rectangular cross-sections.

[0048] Figure 9 shows a second example of the configuration of the connecting member 21. The configuration of the first engaging portion 23 and the fact that the shaft portion 22 and the first engaging portion 23 are integrated are the same, so their explanation will be omitted.

[0049] As shown in Figure 9(a), the shaft portion 22 has a rectangular prism portion 40 in the center of the rod-shaped portion. The cross-section of the rectangular prism portion 40, when cut along the cutting line BB, is hexagonal as shown in Figure 9(b), and has six planes. The rectangular prism portion 40 is positioned so as to be exposed in the joint (approximately 30 mm wide) between two precast floor slabs 12. By inserting a tool such as a wrench into the joint and moving the tool in a predetermined direction, the other end of the shaft portion 22 can be screwed into the second engaging portion 24. The cross-section of the rectangular prism portion 40 is not limited to a hexagon; it may be octagonal, decagonal, or any other polygon as long as it can be gripped with a tool.

[0050] However, with only this, there is a possibility that the second engaging portion 24 may also rotate together. Therefore, as shown in Figure 9(c), the second engaging portion 24 can be equipped with a rotation prevention portion 41 to prevent it from rotating together. The rotation prevention portion 41 is a projection that extends from the second engaging portion 24 toward the first engaging portion 23 when the other end of the shaft portion 22 is screwed into the screw hole 42 of the second engaging portion 24. Even if the second engaging portion 24 rotates together with the shaft portion 22, the width of the space in the first groove portion 26a is smaller than the outer diameter of the second engaging portion 24, so the projection provided on the outer circumference of the second engaging portion 24 abuts against the side wall of the first groove portion 26a and cannot rotate beyond the width of that space. In this way, the protrusion abuts against the side wall of the first groove 26a, preventing the rotation of the second engagement portion 24. As a result, only the shaft portion 22, which is integrally formed with the first engagement portion 23, can be rotated, allowing the other end of the shaft portion 22 to be screwed into the second engagement portion 24. It should be noted that the configuration is not limited to one in which the second engagement portion 24 has a protrusion, as long as the rotation of the second engagement portion 24 together with the shaft portion 22 can be prevented.

[0051] Multiple embedded members 20 are embedded in the connecting surface at the end of the precast floor slab 12 so as to be arranged at predetermined intervals. The interval between the embedded members 20 is, for example, about 400 mm. The gap (joint) between one precast floor slab 12 and the adjacent precast floor slab 12 is narrow, for example, about 30 mm.

[0052] The two precast floor slabs 12 are installed at an interval of approximately 30 mm as described above, the second engaging portion 24 is pre-screwed onto the shaft portion 22 and temporarily fastened, and the integrated connecting member 21 is inserted from above the exposed embedded member 20. The engaging surface 26d on the inside of the stepped portion of the housing section 26 and the first engaging surface 23a of the first engaging section 23 or the second engaging surface 24a of the second engaging section 24 are all formed in a spherical shape so as to be part of a sphere of the same diameter. Even if the two precast deck slabs 12 are laterally misaligned in the direction perpendicular to the bridge axis, as shown in Figure 10, by inserting the connecting member 21 at an angle with respect to the bridge axis direction when viewed from above, and rotating the prismatic portion 40 of the shaft portion 22, it is possible to screw it into the second engaging section 24 and tighten it firmly, thereby bringing the engaging surface 26d of the stepped portion of the housing section 26 of one precast deck slab 12 into close contact with the first engaging surface 23a of the first engaging section 23, and bringing the engaging surface 26d of the stepped portion of the housing section 26 of the other precast deck slab 12 into close contact with the second engaging surface 24a of the second engaging section 24, and fixing them firmly in place.

[0053] Figure 11 is a flowchart illustrating the process of connecting two precast deck slabs 12 using the connecting device described above. This process begins in step 100, and in step 101, the precast deck slab 12 to be connected is placed on the bridge girder 11, adjacent to the first precast deck slab 12. The precast deck slab 12 is lifted using a lifting machine such as a crane and placed in a predetermined position. The precast deck slab to be connected is installed so that the tips of the multiple embedded members 20 exposed on the connecting surface of the first precast deck slab 12 face the tips of the multiple embedded members 20 exposed on the connecting surface of the first precast deck slab 12 installed on the bridge girder 11.

[0054] The precast deck slab 12, like conventional precast deck slabs 12 with loop joints, is equipped with shear prevention holes 15, and the shear prevention devices 13 provided on the upper flange 11a of the bridge girder 11 are inserted into the shear prevention holes 15 and installed on the bridge girder 11.

[0055] In step 102, the connecting member 21 is inserted into the housing portion 26 of the two precast floor slabs 12 so as to straddle the two precast floor slabs 12. At this time, the connecting member 21 is in a state in which the second engaging portion 24 is loosened. The state in which the second engaging portion 24 is loosened means that when the second engaging portion 24 is screwed onto the other end of the shaft portion 22, the second engaging portion 24 is connected to the shaft portion 22 at a position where the distance between the engaging surface 23a of the first engaging portion 23 and the engaging surface 24a of the second engaging portion 24 is longer than the distance between the engaging surfaces 26d of the stepped portion 26 of the housing portion 26 of the two precast floor slabs 12.

[0056] In step 103, the shaft portion 22 is rotated in a predetermined direction and screwed into the second engaging portion 24, thereby screwing the second engaging portion 24 into the shaft portion 22. Even if the precast deck slab 12 to be connected to the one precast deck slab 12 installed on the bridge girder 11 is laterally displaced in the direction perpendicular to the bridge axis and the embedded member 20 is not directly facing it, by inserting the connecting member 21 into the two housing portions 26 and screwing the second engaging portion 24 of the connecting member 21 into the shaft portion 22 and tightening it, the engaging surface 26d of the stepped portion of the housing portion 26 of one embedded member 20 and the second engaging surface 24a of the second engaging portion 24 come into contact over a surface, and the engaging surface 26d of the stepped portion of the housing portion 26 of the other embedded member 20 and the first engaging surface 23a of the first engaging portion 23 come into contact over a surface, exerting bearing resistance force and enabling a strong connection.

[0057] In step 104, determine whether all joints on the connecting surface have been connected. Since multiple joints are provided as connecting devices on the connecting surface, check whether all of these multiple joints have been connected. If there are any joints that have not yet been connected, return to step 101 and repeat steps 101 to 104.

[0058] If all joints on the connecting surface are connected in step 104, proceed to step 105, where grout material is poured into the joint between the two precast deck slabs 12 and into the shear prevention holes 15 into which the shear prevention devices 13 are inserted, integrating the two precast deck slabs 12 and each precast deck slab 12 with the bridge girder 11, and completing the connection work of the two precast deck slabs 12 in step 106. Note that by repeating the work shown in steps 100 to 106, the precast deck slabs 12 can be connected and integrated in the bridge axis direction of the bridge.

[0059] In this way, concrete structures can be efficiently connected even if the embedded members installed at the ends of concrete structures such as deck slabs are not directly facing each other. Furthermore, because the spacing (joints) between concrete structures can be narrowed, there is no need to pour cast-in-place concrete. In other words, the installation of reinforcing bars and formwork becomes unnecessary, improving construction speed and reducing manpower. In addition, since there is no need to pour cast-in-place concrete, the entire width of the deck slab can be precast, improving on-site construction quality.

[0060] The coupling device and coupling method of the present invention have been described in detail with reference to the embodiments shown in the drawings. However, the present invention is not limited to the embodiments described above, and can be modified to include other embodiments, additions, changes, or deletions within the scope that a person skilled in the art can conceive. Any embodiment that achieves the function and effect of the present invention is included within the scope of the present invention.

[0061] Therefore, it is also possible to provide precast floor slabs connected using this connecting device, as well as construction methods for floor slabs constructed by connecting precast floor slabs. [Explanation of Symbols]

[0062] 10…Bridge piers 11…Bridge girder 11a…Upper flange 12, 12a, 12b... Precast floor slabs 13... Prevent slippage 14… Fittings 15… Holes for preventing slippage 16... Loop reinforcement bars 17…Joint space 20… Buried components 21…Connecting member 22... Shaft 23...First engaging part 23a...First engagement surface 24...Second engagement part 24a...Second engagement surface 25…Fixed part 25a... Rib 26...Detention Unit 26a...First groove 26b...Second groove 26c...Third groove 26d…Engagement surface 27…Aperture 28... Side ribs 30… Stabilizing muscles 30a... Rib 31… Anchor plate 40... prism section 41... Anti-rotation part 42... screw holes

Claims

1. A connecting device for connecting concrete structures, A connecting member comprising a rod-shaped shaft portion, a first engaging portion provided at one end of the shaft portion and extending relative to the shaft portion, and a second engaging portion provided at the other end of the shaft portion and extending relative to the shaft portion, An embedded member including a fixing portion embedded in the concrete structure and a housing portion exposed at the end of the concrete structure, which can accommodate the first engaging portion or the second engaging portion and a part of the shaft portion. Includes, The first engaging portion, the second engaging portion, or both are connected to the shaft so as to be movable in the longitudinal direction of the shaft. A coupling device in which the surfaces that engage with the housing portion and the first engaging portion or the second engaging portion are formed in a spherical shape.

2. The coupling device according to claim 1, wherein the shaft portion and the first engaging portion are integrally formed, and the second engaging portion is detachably connected to the shaft portion.

3. The second engaging portion is configured to be screwed onto the shaft portion, The coupling device according to claim 1, wherein the shaft portion is provided with a prismatic portion having a plurality of planes at the center of the shaft portion in the longitudinal direction.

4. The housing portion includes, when viewed from the insertion direction of the connecting member, a first groove having a width into which the shaft portion can be inserted, and a second groove having a wider width than the first groove into which the first engaging portion or the second engaging portion can be inserted. The coupling device according to claim 3, wherein the second engaging portion extends toward the first engaging portion and includes a rotation prevention portion that abuts against the side wall of the first groove as the shaft rotates about the axis of the shaft, thereby preventing it from rotating together with the shaft.

5. The connecting device according to any one of claims 1 to 4, wherein the concrete structure is a precast deck slab for a bridge.

6. A method of connecting concrete structures using a connecting device, The coupling device is A connecting member comprising a rod-shaped shaft portion, a first engaging portion provided at one end of the shaft portion and extending relative to the shaft portion, and a second engaging portion provided at the other end of the shaft portion and extending relative to the shaft portion, An embedded member including a fixing portion embedded in the concrete structure and a housing portion exposed at the end of the concrete structure, which can accommodate the first engaging portion or the second engaging portion and a part of the shaft portion. Includes, The process of installing two concrete structures by positioning them close together so that the embedded members of each concrete structure face each other, The steps include inserting the connecting member into the housing portion of the two concrete structures, A step of moving the first engaging portion or the second engaging portion or both, which are connected to the shaft portion so as to be movable in the longitudinal direction of the shaft portion, to engage the spherical engaging surface of the housing portion with the spherical engaging surface of the first engaging portion or the second engaging portion. A connection method that includes this.

7. The second engaging portion is configured to be screwed onto the shaft portion, The shaft portion is provided with a prismatic portion having multiple planes at its longitudinal center, The connecting method according to claim 6, wherein in the engagement step, a tool is used that contacts at least two of the planes of the rectangular prism and rotates the shaft portion about the axis of the shaft portion, and the second engaging portion is screwed onto the shaft portion and tightened by rotating the shaft portion.

8. The housing portion includes, when viewed from the insertion direction of the connecting member, a first groove having a width into which the shaft portion can be inserted, and a second groove having a wider width than the first groove into which the first engaging portion or the second engaging portion can be inserted. The second engaging portion extends toward the first engaging portion and includes a rotation prevention portion that abuts against the side wall of the first groove as the shaft rotates around its axis, thereby preventing it from rotating together with the shaft. The coupling method according to claim 7, wherein in the engagement step, the second engaging portion is screwed onto the shaft portion and tightened while preventing it from rotating together with the shaft portion by the rotation prevention portion.

9. The connection method according to any one of claims 6 to 8, wherein the concrete structure is a precast deck slab for a bridge.

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