Precast concrete slab joint

Abstract

To provide a precast concrete slab joint that prevents construction defects by allowing the joint to be fastened with bolts of the same standard so that the threading length (threading amount) is uniform, even if there is a step difference in the adjacent precast concrete slab when it is installed on the main girder. [Solution] The precast concrete slab joint 10 has a housing portion 12 into which a connecting member 20 of a receiving member 15 is inserted, a pair of insertion portions 22 into which the connecting member 20 is inserted into the housing portion 12 of the receiving member 15, and a bridging portion 21 connecting the insertion portions 22, a bolt 30 for fastening the insertion portions 22 of the receiving member 15, a female screw hole 16 formed in the bottom portion of the housing portion 12 into which the male screw portion 34 of the bolt 30 is screwed, and a stepped washer 40 that abuts against the upper and / or lower end surfaces of the respective insertion portions 22 and is selectively disposed between the insertion portion 22 and the head 32 of the bolt 30 and / or between the insertion portion 22 and the bottom portion according to the height difference of the pair of receiving members 15.

Description

Technical Field

[0001] The present invention relates to a precast concrete floor slab joint for connecting a plurality of road bridge floor slabs.

Background Art

[0002] In the construction of road bridges and the like, technologies have been proposed to improve the durability, water stoppage property, etc. of the connecting portion of precast concrete floor slabs so that the connecting work, disconnection work, etc. between precast concrete floor slabs for bridges can be facilitated.

[0003] For example, Patent Document 1 and Patent Document 2 disclose a technology of a cotta floor slab method using a so-called cotta joint that joins precast concrete floor slabs with a mechanical joint instead of the conventional method of joining adjacent precast concrete floor slabs with in-situ concrete.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, when precast concrete deck slabs are installed on the main girders, the height is adjusted in a direction perpendicular to the longitudinal direction of the main girder, which is the bridge axis direction, using adjustment bolts on the upper flange of the main girder. However, even if the height of the precast concrete deck slab is adjusted with adjustment bolts, product tolerances, construction errors, twisting due to curved sections, deflection of the main girder and / or the steel bridge pier itself, deflection due to bridge deck loads, deflection of the main girder due to temporary structures, etc., can cause a step difference in height in the direction perpendicular to the longitudinal direction of the main girder at the joints of adjacent precast concrete deck slabs.

[0006] Thus, in the cotter-type joints described in Patent Documents 1 and 2, when connecting precast concrete floor slabs with steps at the joint portions, inserting an H-shaped cotter into opposing C-shaped joint fittings and tightening it with bolts results in different bolt threading lengths (thickness) for each C-shaped joint fitting.

[0007] Therefore, conventional cotter joints have the problem of variations in the axial force of the two bolts that fasten the joint portion of the precast concrete floor slabs being connected. In addition, with conventional cotter joints, when fastening the joint portion using bolts of different lengths to ensure that the threaded length into each C-type joint fitting is equal, it is necessary to prepare bolts of different specifications with different bolt lengths according to the difference in height, and there is a risk of construction defects due to the selection of the wrong bolt.

[0008] Furthermore, with conventional cotter joints, if a long bolt is mistakenly used, the tip of the bolt's threaded portion will protrude from the back of the C-type joint fitting. As a result, the concrete covering the back of the C-type joint fitting, which is of the correct thickness, may be pushed and damaged, potentially leading to spalling. This also presented a problem with conventional cotter joints, as it could lead to construction defects.

[0009] Therefore, the present invention has been made in view of the above circumstances, and aims to provide a precast concrete slab joint that prevents construction defects by allowing the joint portion to be fastened with bolts of the same standard so that the screw-in length (threading amount) is uniform, even if there is a step difference in adjacent precast concrete slabs when they are installed on the main girder. [Means for solving the problem]

[0010] A precast concrete slab joint according to one aspect of the present invention is a precast concrete slab joint that connects adjacent precast concrete slabs by comprising a receiving member disposed on a precast concrete slab and a connecting member that spans and connects a pair of opposing receiving members, wherein each receiving member has a housing portion into which the connecting member is inserted, and the connecting member has a pair of insertion portions that are fitted into each housing portion of the receiving member and a bridging portion that connects the insertion portions, above Insertion part Each of them to the above receiving member A bolt for fastening, a female threaded hole formed in the bottom of each of the above-mentioned housing portions into which the male threaded portion of the bolt is screwed, and a pair of receiving members that abut against the upper and / or lower end surfaces of each of the above-mentioned insertion portions, selectively according to the height difference of the pair of receiving members. Each Between the above-mentioned insertion portion and the head of the above-mentioned bolt and / or Each Displaced between the insertion portion and the bottom portion The amount of threading of each male threaded portion of the bolt into the female threaded hole is made constant and uniform. It has a stepped washer.

[0011] Furthermore, the above precast concrete slab joint is equipped with the above stepped washer. pair Each of the above insertion parts multiple A number of them will be provided.

[0012] Furthermore, the precast concrete slab joint described above has a hole through which the bolt is inserted in the insertion portion, and the length of the shaft portion of the bolt, where the male thread portion is formed, is set to be longer than the sum of the length of the hole and the thickness of the stepped washer.

[0013] Furthermore, in the above-mentioned precast concrete slab joint, the length of the shaft portion of the bolt on which the male threaded portion is formed is set to be less than or equal to the sum of the length of the hole, the thickness of the stepped washer, and the depth of the female threaded hole.

[0014] Furthermore, the above-mentioned precast concrete slab joint has a recess at the top of each insertion portion that can be arranged to surround the head of the bolt and the stepped washer, and the depth of the recess is set to be greater than or equal to the sum of the height of the bolt head and the thickness of the stepped washer.

[0015] Furthermore, in the above-mentioned precast concrete slab joint, the inner bottom surface of the recess constitutes the upper end surface of the insertion portion. [Effects of the Invention]

[0016] According to the present invention, even if there is a step difference between adjacent precast concrete slabs when they are installed on the main girder, the joint portion can be fastened with bolts of the same standard so that the screw-in length (threading amount) is uniform, thereby providing a precast concrete slab joint that prevents construction defects. [Brief explanation of the drawing]

[0017] [Figure 1] A perspective view showing a precast RC slab, to which a precast concrete slab joint according to one aspect of the present invention is applied, being placed on the main girder. [Figure 2] The same, a plan view partially showing a precast RC slab with precast concrete slab joints applied. [Figure 3] The same perspective view shows the configuration of a precast concrete slab joint in a state where adjacent precast reinforced concrete slabs are connected. [Figure 4] The same is an exploded perspective view showing the configuration of a precast concrete slab joint that connects adjacent precast reinforced concrete slabs. [Figure 5] This perspective view shows the configuration of a position adjustment erection member that is inserted into a pair of receiving members of a precast concrete slab joint to adjust the position of adjacent precast RC slabs. [Figure 6] Partial cross-sectional view showing the state before the position adjustment and erection member is inserted into a pair of receiving members of a precast concrete floor slab joint [Figure 7] Partial cross-sectional view showing the state where the position adjustment and erection member is lowered and inserted between the opposing receiving members with the male screw body [Figure 8] Partial cross-sectional view showing the state where the position adjustment and erection member is inserted into a pair of receiving members of a precast concrete floor slab joint [Figure 9] Plan view showing a pair of receiving members in a state displaced in the Y direction [Figure 10] Plan view showing a pair of receiving members whose displacement has been adjusted to an appropriate connection position [Figure 11] Cross-sectional view showing the dimensional relationship of the components of a precast concrete floor slab joint [Figure 12] Exploded perspective view showing the state where a connecting member is inserted into the opposing receiving members of a precast concrete floor slab joint [Figure 13] Exploded perspective view showing the state where bolts are fastened to the connecting member inserted into a pair of receiving members of a precast concrete floor slab joint [Figure 14] Cross-sectional view showing a precast concrete floor slab joint where the surface positions of precast RC floor slabs are at the same height [Figure 15] Cross-sectional view of a precast concrete floor slab joint for explaining the state where a connecting member is fastened to a receiving member with a step [Figure 16] Cross-sectional view showing a precast concrete floor slab joint in a state where a connecting member is fastened to a receiving member with a step [Figure 17] Cross-sectional view showing a precast concrete floor slab joint in which a connecting member is fastened to a receiving member with a step having a different height difference from that in Fig. 16 <00​​​The second modified example is shown in an exploded perspective view illustrating an example of a precast concrete slab joint consisting of a well-known C-type joint fitting and an H-type cotter for connecting adjacent precast RC slabs. [Figure 20] The second modified example is shown in an exploded perspective view illustrating another example of a precast concrete slab joint consisting of a well-known C-type joint fitting and an H-type cotter for connecting adjacent precast RC slabs. [Figure 21] The third modified example is a plan view showing a precast concrete slab joint, where Figure 21(a) illustrates a cotter having an H-shaped intermediate connecting section, Figure 21(b) illustrates a cotter having an intermediate connecting section in which the flanges are connected by two webs, and Figure 21(c) illustrates a cotter having a rectangular O-shaped intermediate connecting section. [Figure 22] The fourth modification relates to a plan view showing a precast concrete slab joint, where Figure 22(a) illustrates an H-shaped cotter having a pair of rectangular insertion parts in plan view, Figure 22(b) illustrates an H-shaped cotter having a pair of trapezoidal insertion parts in plan view, and Figure 22(c) illustrates an H-shaped cotter having a pair of triangular insertion parts in plan view. [Modes for carrying out the invention]

[0018] The precast concrete slab joint of the present invention will be described below with reference to the drawings. Please note that the drawings based on each embodiment in the following description are schematic, and the relationship between the thickness and width of each part, as well as the ratio of the thicknesses of each part, may differ from the actual dimensions, and there may be differences in dimensional relationships and ratios between drawings.

[0019] The precast concrete deck joint of the present invention connects road bridge decks made of precast concrete, such as precast RC decks, composite decks (steel-concrete composite decks), and precast PC decks, which are used to construct elevated roads, expressways, bridges (road bridges), etc. Here, the case of connecting precast RC decks as road bridge decks on a bridge pier will be explained as an example.

[0020] Figure 1 is a perspective view showing a precast RC deck slab to which the precast concrete deck slab joint according to this embodiment is applied, placed on the main girder; Figure 2 is a plan view partially showing a precast RC deck slab to which the precast concrete deck slab joint is applied; Figure 3 is a perspective view showing the configuration of the precast concrete deck slab joint in a state where adjacent precast RC deck slabs are connected; and Figure 4 is an exploded perspective view showing the configuration of the precast concrete deck slab joint connecting adjacent precast RC deck slabs.

[0021] Furthermore, in the following explanation, the direction along the longitudinal direction of the main girder, which is the bridge axis direction, may be referred to as the X direction, the direction along the short direction of the main girder perpendicular to the X direction, which is the Y direction, and the direction perpendicular to the XY plane, which is the Z direction. Also, for example, if the XY plane is a plane parallel to the horizontal plane, the Z direction will be the vertical direction.

[0022] As shown in Figure 1, multiple precast RC deck slabs 1 are installed in a row in the Y direction, which is perpendicular to the bridge axis, which is the X direction. Here, the precast RC deck slabs 1 are stretched and fixed over the four main girders 100. Therefore, each precast RC deck slab 1 is connected along the longitudinal direction (X direction) of the main girder 100, which is the bridge axis direction. Then, as shown in Figures 2 and 3, adjacent precast RC deck slabs 1 are connected by multiple precast concrete deck slab joints (hereinafter simply referred to as joints) 10.

[0023] The joint 10 in this embodiment constitutes a so-called cotter-type joint structure. As shown in Figures 3 and 4, the joint 10 has a pair of receiving members 15 (15a, 15b), a connecting member 20, two bolts 30, and a total of six stepped washers 40 (41, 42, 43), in this case three washers on each side for the two receiving members 15 (15a, 15b). Multiple of these joints 10 are arranged along the longitudinal (Y-direction) edges of adjacent precast RC floor slabs 1, and the connecting member 20 is inserted from above along the Z-direction into the two opposing receiving members 15 (15a, 15b).

[0024] The receiving member 15 of the joint 10 constitutes a C-shaped metal fitting made of a casting, for example, cast iron, aluminum alloy, or copper alloy. While the receiving member 15 is described as a C-shaped metal fitting made of a casting, it is sufficient as long as it has adequate strength for connecting the precast RC floor slabs 1 (1a, 1b) together. It is not limited to being a casting, a machined version of a casting, or made of metal.

[0025] The receiving member 15 is embedded at a predetermined depth, for example, 40 mm from the surface of the precast RC floor slab 1. For this reason, each precast RC floor slab 1 (1a, 1b) has a recess 2 (2a, 2b) that is cut out from the surface in a roughly circular shape (roughly keyhole-shaped, keyhole-shaped mound-shaped) and notched out to the side, so that the receiving member 15 to be embedded is exposed.

[0026] The receiving member 15 is connected to multiple anchors 11, in this case four, which serve as anchoring reinforcement bars embedded in the precast RC floor slab 1 in the short direction (X direction). Each anchor 11 is positioned on the receiving member 15 by screw connection, welding, or the like. Alternatively, each anchor 11 may be integrally formed with the receiving member 15 through casting.

[0027] The receiving member 15 has a housing portion 12, an inclined guide surface 13, and a connecting member insertion portion 14. The housing portion 12 defines a bottomed internal space with a substantially circular opening formed on the upper surface of the receiving member 15. The inclined guide surface 13 has a tapered inner circumferential surface that widens in diameter on the opening side of the housing portion 12.

[0028] The connecting member insertion portion 14 is a gap that communicates with the housing portion 12 and the inclined guide surface 13, having a predetermined width that allows the connecting member 20 to be inserted. The receiving member 15 has a tapered wall surface on the opposing surface that defines the connecting member insertion portion 14, which narrows towards the depth.

[0029] Furthermore, the inclined guide surface 13 guides one side of the connecting member 20 entering the housing section 12 toward the center of the housing section 12. That is, the inclined guide surface 13 gradually slopes radially outward from inside the housing section 12 toward the upper opening end. For this reason, the inclined guide surface 13 is a tapered surface that gradually narrows the opening of the housing section 12 in the direction in which the upper opening of the receiving member 15 is widened and the connecting member 20 is inserted.

[0030] Furthermore, the receiving member 15 has a female screw hole 16 and a restricting recess 17 at its lower bottom end (see Figure 6). The female screw hole 16 is drilled in the bottom at approximately the center that defines the inner bottom surface of the housing portion 12. The restricting recess 17 is recessed from the lower end surface (back surface) side of the receiving member 15. The restricting recess 17 has a restricting portion 18. The restricting portion 18 extends towards the top surface of the restricting recess 17.

[0031] Although the pair of receiving members 15 (15a, 15b) are substantially the same shape, they are not limited to being the same shape and may be different shapes as long as they are at least capable of accommodating the connecting member 20.

[0032] The connecting member 20 of the joint 10, like the receiving member 15, is a casting or product formed by casting from a metal material such as cast iron, aluminum alloy, or copper alloy, or a product made by machining such a material, and constitutes an I-shaped connecting fitting. However, the connecting member 20 is not limited to being made of a metal material as long as it has sufficient strength to connect the precast RC floor slabs 1 (1a, 1b) together.

[0033] The connecting member 20 has a bridging portion 21 that is roughly rectangular in shape, and a pair of insertion portions 52 disposed at both ends of the bridging portion 21. Each insertion portion 22 is roughly cylindrical in shape and connected to the bridging portion 21. The insertion portions 22 are positioned in the space formed by the housing portion 12 and the connecting member insertion portion 14 of the opposing pair of receiving members 15 (15a, 15b).

[0034] It is preferable that the insertion portion 22 has a slight clearance from the receiving portion 12 of the receiving member 15 in order to absorb construction (installation) errors of the precast RC floor slab 1, dimensional errors of the precast RC floor slab 1 itself, twisting, warping, and other product (manufacturing) errors.

[0035] Therefore, the insertion portion 22 is set to have an outer diameter less than the inner diameter of the housing portion 12 of the receiving member 15. As a result, a small gap is formed between the housing portion 12 of the receiving member 15 and the insertion portion 22 of the connecting member 20, allowing the curable fluid to be actively injected.

[0036] Furthermore, the insertion portion 22 has a cylindrical recess 23 at its upper part and a through hole 24 formed from approximately the center of the recess 23 downward (in the Z direction).

[0037] The recess 23 of the insertion portion 22 has an inner diameter that is sufficiently larger than the outer diameter of the outward-facing flange 33 so that the head 32 of the bolt 30 can be radially displaced relative to the recess inside and have sufficient error absorption. The hole 24 of the insertion portion 52 has a hole diameter that allows the shaft 31 of the bolt 30 to pass through freely.

[0038] In this context, the bolt 30 is a flanged hexagonal bolt having a head 32 with an outward-facing flange 33 integrally formed at one end of the shaft portion 31. Furthermore, the bolt 30 has a male threaded portion 34 engraved in a predetermined range at the other end of the shaft portion 31.

[0039] The hole 24 in this case is set to have a diameter that allows the shaft portion 31 of the inserted bolt 30 to be displaced radially relative to the hole, and to absorb errors sufficiently. That is, the hole 24 is set to have a diameter that is sufficiently larger than the diameter of the shaft portion 31 of the bolt 30. Also, the hole 24 is set to have a diameter that is smaller than the outer diameter of the outward flange 33 provided on the head 32 of the bolt 30.

[0040] Furthermore, the inner diameter of the hole 24 may be set to be larger than the outer diameter of the outward-facing flange 33. In this case, by using stepped washers 40 (41, 42, 43) with sufficient area, thickness, and strength, the head 32 of the bolt 30 can be prevented from entering or sinking into the hole 24. There is no particular limit to the number of stepped washers 40 (41, 42, 43) used, but it is preferable to use neither too many nor too few to avoid complexity.

[0041] These stepped washers 40 (41, 42, 43) are washer-shaped members that form a roughly annular shape. The stepped washers 40 (41, 42, 43) only need to be shaped in such a way that a bolt 30 can be inserted through them and that they can support the connecting member 20. For example, they may be shaped like a flat washer, a spring washer, a disc spring washer, a toothed washer, a spherical washer, etc.

[0042] The recess 23 of the insertion portion 52 surrounds the head 32 of the bolt 30 inserted through the hole 24. That is, the surface around the hole 24, which forms the bottom surface of the recess 23, constitutes an inward flange that provides a reaction force due to the fastening of the bolt 30.

[0043] When connecting precast RC floor slabs 1 (1a, 1b) by fixing the insertion portion 22 of the connecting member 20 which is fitted into a pair of receiving members 15 (15a, 15b), the threaded portion 34 of the shaft portion 31 of the bolt 30 is screwed into the female threaded hole 16 formed in the bottom of the receiving member 15. At this time, for one side of the insertion portion 22 of the connecting member 20, for example, three stepped washers 40 (41, 42, 43) are appropriately combined and installed between the receiving members 15 (15a, 15b) and the connecting member 20 and / or in the recess 23 of the insertion portion 22.

[0044] Each stepped washer 40 (41, 42, 43) is a flat washer having a hole through which the shaft portion 31 of the bolt 30 can be freely inserted. Each stepped washer 40 (41, 42, 43) is set to have an outer dimension that allows it to be placed in the recess 23 of the insertion portion 22. Each stepped washer 40 (41, 42, 43) can also be set so that it does not enter or sink into the hole 24 of the insertion portion 22.

[0045] That is, the outer diameter of each stepped washer 40 (41, 42, 43) is less than the inner diameter of the recess 23, and has an outer diameter that is sufficiently larger than the hole diameter of the hole 24. In this case, for one side of the insertion portion 22, three stepped washers 40 (41, 42, 43) are used as a set, and for example, the three may have the same thickness or different thicknesses, or two may have the same thickness and one may have a different thickness so that multiple thicknesses can be adjusted.

[0046] In other words, if all three stepped washers 40 (41, 42, 43) are set to a thickness of T mm, for example, the height of the insertion section 22 can be selectively adjusted from T mm to 3 T mm in T mm increments, depending on the number of washers installed above and below the insertion section 22, by their combination. Furthermore, if, for example, one stepped washer 40 (41) is set to a thickness of 3 T mm and the two stepped washers 40 (42, 43) are set to a thickness of T mm, the height of the insertion section 22 can be selectively adjusted from T mm to 5 T mm in T mm increments, depending on the number of washers installed above and below the insertion section 22, by their combination.

[0047] Furthermore, for one insertion portion 22, if, for example, one stepped washer 40(41) has a thickness of Tmm and two stepped washers 40(42,43) have a thickness of 2Tmm, forming a set of three stepped washers 40(41,42,43), it will similarly be possible to selectively adjust the thickness from Tmm to 5Tmm in Tmm increments.

[0048] In addition, for example, in the case of a set of three stepped washers 40(41,42,43) with stepped washers 40(41) set to a thickness of Tmm, stepped washers 40(42) set to a thickness of 2Tmm, and stepped washers 40(43) set to a thickness of 3Tmm for one side of the insertion portion 22, it becomes possible to selectively adjust from Tmm to 6Tmm in Tmm increments.

[0049] Furthermore, the thickness of each stepped washer 40 can be set as appropriate, and the number of washers is not limited to three per insertion portion 22 on one side; it may be one or two or more.

[0050] Here, the position adjustment erection member 50 used when connecting precast RC slabs 1 (1a, 1b) will be described below. Figure 5 is a perspective view showing the configuration of a position adjustment erection member that is inserted into a pair of receiving members of a precast concrete slab joint to adjust the position of adjacent precast RC slabs.

[0051] As shown in Figure 5, the position adjustment erection member 50 is a casting formed from a metal material such as cast iron, aluminum alloy, or copper alloy, and has a roughly dumbbell shape in plan view. However, the position adjustment erection member 50 is not limited to being made of a metal material such as a casting, as long as it has sufficient strength to connect the precast RC floor slabs 1 (1a, 1b) together.

[0052] The position-adjusting erection member 50 mainly comprises a bridging section 51 and a pair of insertion sections 52 arranged on both sides of the bridging section 51. The pair of insertion sections 52 can be inserted into the two opposing receiving members 15 (15a, 15b) of the joint 10, respectively.

[0053] The insertion portion 52 as a whole has a shape that is roughly like an inverted mushroom, with the cap portion positioned downwards. As shown in Figures 6 and 7, the insertion portion 52 has an insertion relief portion 52a that is roughly cylindrical in shape and extends upward along the Z direction. Figure 6 is a partial cross-sectional view showing the state before the position adjustment erection member is inserted into the pair of receiving members of the precast concrete slab joint, and Figure 7 is a partial cross-sectional view showing the state after the position adjustment erection member has been lowered and the male screw body has been inserted between the opposing receiving members.

[0054] Furthermore, the insertion portion 52 has a guide portion 53 in which an insertion portion 53a is formed below the insertion relief portion 52a along the Z direction. The guide portion 53 is cylindrical in shape and has a relatively larger diameter than the insertion relief portion 52a.

[0055] The guide portion 53 has a tapered shape, gradually decreasing in diameter towards its lower end. That is, the guide portion 53 has a roughly inverted frustoconical shape. Although the shape of the guide portion 53 is described as a roughly inverted frustoconical shape, it is of course not limited to this, and other shapes such as a roughly triangular pyramidal shape, a roughly square pyramidal shape, a roughly polygonal pyramidal shape, a roughly conical shape, or a roughly polygonal frustoconical shape can also be adopted, with a tapered tip that facilitates entry into the housing portion 12.

[0056] Of course, the gradual reduction in diameter of this guide section 53 may be configured as a hemispherical shape, other curved shapes, or combinations thereof. Similarly, the shape of the internal space within the area enclosed by the inclined guide surface 13 of the housing section 12 can be a roughly inverted frustoconical shape, a roughly polygonal frustoconical shape, or the like.

[0057] In this context, the insertion relief portion 52a is set to have a roughly cylindrical shape, but its outer shape does not necessarily have to be cylindrical. It is sufficient that it is smaller in the radial direction than the outer dimensions of the insertion portion 53a, and can take any desired outer shape, such as a polygonal or elliptical shape.

[0058] The insertion portion 52 has its largest outer diameter at the insertion portion 53a of the guide portion 53. The insertion portion 53a has an outer diameter that is equal to or slightly smaller than the inner diameter of the housing portion 12 of the receiving member 15 (15a, 15b). It is preferable that the outer diameter of the insertion portion 53a be slightly smaller than the inner diameter of the housing portion 12 in order to improve ease of insertion into and removal from the housing portion 12.

[0059] Therefore, the insertion portion 53a can be fitted into the receiving member 15 (15a, 15b) with its maximum outer diameter portion in close contact with the inner circumferential surface of the housing portion 12, at least partially or entirely.

[0060] Furthermore, the insertion portion 52 can be appropriately configured in terms of the axial length of the insertion portion 53a and the guide portion 53 along the Z direction, as well as the insertion relief portion 52a. In this case, the axial length of the insertion portion 53a and the guide portion 53 along the Z direction is set to be shorter than that of the insertion relief portion 52a.

[0061] Furthermore, the lower end surface of the guide portion 53 is configured to coincide with the inner bottom surface of the housing portion 12 of the receiving member 15 (15a, 15b). In addition, the lower end surface of the guide portion 53 is configured to form a continuous plane within substantially the same plane as the lower end surface of the bridge portion 51. As a result, when a downward load along the Z direction is applied to the central part of the bridge portion 51 spanning between the insertion portions 52, the stress distributed at the boundary between the lower end of the guide portion 53 and the lower end surface of the bridge portion 51 is relieved. Therefore, the position adjustment erection member 50 is configured to prevent tearing that may occur at the boundary between the lower end of the guide portion 53 and the lower end surface of the bridge portion 51.

[0062] The position adjustment erection member 50, like the connecting member 20, has a cylindrical recess 54 at the top of the insertion portion 52 and a through hole 59 formed from approximately the center of the recess 54 downward along the Z direction. The recess 54 of the insertion portion 52, like the recess 23 of the connecting member 20, is set to have an inner diameter that is sufficiently larger than the outer diameter of the outward flange 33 of the bolt 30 so that the head 32 of the bolt 30 can be relatively displaced radially inside and sufficiently absorb errors. The hole 59 of the insertion portion 52 has a hole diameter that allows the shaft portion 31 of the bolt 30 to be inserted freely.

[0063] The bridging portion 51 has a through hole (not shown) that penetrates it along the Z direction in its approximate center, through which a male threaded body 58 is inserted. That is, the through hole opens on the upper and lower surfaces of the bridging portion 51 approximately in the center. The male threaded body 58 is inserted and positioned in the through hole of the bridging portion 51. The male threaded body 58 has a shaft portion 31 and a pressing portion 56 that acts as a locking body, provided at the lower end of the shaft portion 31. The male threaded body 58 is used with the pressing portion 56 positioned on the lower side where the guide portion 53 is located.

[0064] The male threaded body 58 has a female threaded body, a flange nut 57, attached to the other end opposite the pressing portion 56. The flange nut 57 is attached to the upper end of the male threaded body 58 that extends from the upper surface of the bridging portion 51. Therefore, the flange nut 57 is installed above the bridging portion 51.

[0065] The shaft portion 31 has a male screw thread groove 55a on its outer circumferential surface into which a flange nut 57 is screwed. The area in which the male screw thread groove 55a is formed may be the entire shaft portion 31, or it may be a predetermined area from the tip to the middle of the shaft portion 31. In this case, the male screw thread groove 55a is formed in a predetermined area from the tip to the middle of the shaft portion 31.

[0066] Furthermore, a breakable portion 55b may be formed in the middle of the shaft portion 31, with a V-groove engraved in the circumferential direction. The breakable portion 55b is set to have the smallest cross-sectional area in the shaft portion 31. Therefore, the breakable portion 55b can be the part of the shaft portion 31 that is the first to break when a torque or axial force above a predetermined level is applied.

[0067] The pressing portion 56 is a roughly rectangular block-shaped rod extending in the XY plane direction such that the lower end of the shaft portion 31 forms an inverted T shape. That is, the pressing portion 56 has a pair of short sides and a pair of long sides. The short sides are set to a length less than the gap between the receiving members 15 (15a, 15b) when connected. The long sides are set to a length greater than the gap between the receiving members 15 (15a, 15b) when connected.

[0068] Furthermore, the pressing portion 56 is not limited to a rectangular block-shaped rod, as long as it has portions corresponding to the short side and the long side, it may also be a rod with a roughly elliptical shape, a roughly oblong shape, a polygonal shape, or the like.

[0069] The position adjustment mounting member 50 has its shaft portion 31 inserted from the pressing portion 56 side of the male screw body 58 between opposing receiving members 15 (15a, 15b) (see Figure 6). This allows the pressing portion 56 to remain non-contact with each receiving member 15 (15a, 15b).

[0070] Then, the position adjustment erection member 50 is rotated by the male screw body 58, causing the pressing portion 56 to rotate approximately 90° from the Y direction to the X direction (see Figure 7). At this time, the longer side of the pressing portion 56 becomes parallel to the X direction, and is in a state where it can contact (interfere with) both of the regulating recesses 17 of the receiving member 15 (15a, 15b).

[0071] The position adjustment erection member 50 configured as described above is used during the positioning process of opposing receiving members 15 (15a, 15b) when connecting adjacent precast RC floor slabs 1 (1a, 1b). Of the pair of receiving members 15 (15a, 15b), the one positioned on the precast RC floor slab 1a side is called receiving member 15a, and the one positioned on the precast RC floor slab 1b side is called receiving member 15b.

[0072] The precast RC slabs 1(1a,1b) are arranged adjacent to each other along the X direction with their respective support members 15(15a,15b) facing each other. One of the precast RC slabs 1(1a,1b), precast RC slab 1a, is already fixed onto multiple main girders 100 through a positioning process. The other precast RC slab 1b is erected in a state where it can be displaced across multiple main girders 100 located in close proximity to precast RC slab 1a.

[0073] At this time, the precast RC slab 1b is positioned (crane set) on the precast RC slab 1a by lifting it with a crane or the like, so that it is approximately parallel to the Y direction which is perpendicular to the longitudinal direction (X direction) of the multiple main girders 100, and is lined up in the X direction. Then, the insertion parts 52 provided on both sides of the position adjustment erection member 50 are inserted into each housing part 12 so that adjacent precast RC slabs 1 (1a, 1b) are erected by straddling each of the opposing pair of receiving members 15 (15a, 15b).

[0074] At this time, as shown in Figure 6, a flange nut 57, which is a female thread, is screwed onto the upper end portion of the male thread body 58. The male thread body 58 is then oriented in advance so that the orientation of the long side portion of the pressing portion 56 is parallel to the Y direction, so as not to interfere with each receiving member 15 (15a, 15b).

[0075] From this state, the position adjustment erection member 50 is positioned above each receiving member 15 (15a, 15b) so as to straddle them, and is lowered toward each receiving member 15 (15a, 15b). At this time, the male screw body 58 is introduced into the gap between the receiving members 15 (15a, 15b) of the precast RC floor slab 1 (1a, 1b).

[0076] The pressing portion 56 may be positioned vertically so as to enter the restrictive recess 17 of each receiving member 15 (15a, 15b), or it may be positioned lower than the restrictive recess 17. The precast RC floor slab 1 (1a, 1b) has recesses 3 (3a, 3b) formed in it that communicate with the restrictive recess 17 of the receiving member 15 (15a, 15b) to avoid interference (contact) with the pressing portion 56.

[0077] If the precast RC floor slabs 1 (1a, 1b) are spaced further apart than the appropriate connection position, the insertion portion 52 of the position adjustment erection member 50 can be locked in place by contacting the inclined guide surface 13 near the upper end opening of the housing portion 12. That is, the position adjustment erection member 50 is lowered toward each receiving member 15 (15a, 15b), and the guide portion 53 provided at the lower end of the insertion portion 52 contacts the inclined guide surface 13 provided near the upper end opening of the respective housing portion 12 of each receiving member 15 (15a, 15b).

[0078] Then, torque in the fastening direction is applied to the flange nut 57 by a fastening tool such as a manual wrench or an electric nut runner. When the flange nut 57 is rotated in the fastening direction, it rotates and settles so that the pressing portion 56 enters the regulating recess 17.

[0079] When the pressing portion 56 is in a position to enter the restricting recess 17, the male screw body 58 rotates in conjunction with the rotation of the flange nut 57. Consequently, the pressing portion 56 rotates approximately 90° to enter the restricting recess 17 and comes into contact with the restricting portion 18, thereby restricting its rotation.

[0080] Furthermore, if the pressing portion 56 is located below the restrictive recess 17, it will interfere with the precast RC slab 1 (1a, 1b). In this state, the flange nut 57 is tightened into the male screw thread groove 55a formed on the shaft portion 31 of the male screw body 58, causing the male screw body 58 to be displaced upward relative to the bridging portion 51 of the position adjustment erection member 50. As a result, the pressing portion 56 is displaced upward to a position where it can enter the restrictive recess 17 of the precast RC slab 1 (1a, 1b).

[0081] When the pressing portion 56 is in a position to enter the restricting recess 17, the male screw body 58 rotates in conjunction with the rotation of the flange nut 57. Consequently, the pressing portion 56 rotates approximately 90° to enter the restricting recess 17, comes into contact with the restricting portion 18, and its rotation is restricted.

[0082] Furthermore, when torque is applied to the flange nut 57 in the fastening direction, the pressing portion 56 presses against the lower end surface of the regulating recess 17 of each receiving member 15 (15a, 15b). The flange nut 57 also presses the position adjustment erection member 50 toward each receiving member 15 (15a, 15b). Therefore, by tightening the upper flange nut 57, the lower pressing portion 56 presses the receiving members 15 (15a, 15b) and the bridging portion 51 of the position adjustment erection member 50 toward each other.

[0083] Of the support members 15 (15a, 15b), the support member 15b on the side of the precast RC slab 1b, which is displaceable, is displaced along the X direction toward the precast RC slab 1a fixed to the main girder 100 by pressure from the guide portion 53 of the position adjustment erection member 50 which is in contact with the inclined guide surface 13.

[0084] In other words, when the flange nut 57 of the position adjustment erection member 50 is tightened, a force is generated that presses the bridge section 51 in the negative direction (vertically downward) along the Z direction. Then, the guide portion 53 of the insertion portion 52 of the position adjustment erection member 50, which is inserted into the housing portion 12 of each receiving member 15 (15a, 15b), comes into contact with the inclined guide surface 13 and slides.

[0085] As a result, the position adjustment erection member 50 can apply a force Fx in the X direction to press the displaceable receiving member 15b on the precast RC slab 1b side toward the receiving member 15a of the opposing precast RC slab 1a. That is, the position adjustment erection member 50 displaces the precast RC slab 1b via the receiving member 15b toward the receiving member 15a of the opposing precast RC slab 1a, thereby reducing the relative distance.

[0086] Therefore, as the flange nut 57 of the position adjustment erection member 50 is rotated in the fastening direction, the receiving member 15b is gradually displaced toward the receiving member 15a. As a result, each of the insertion portions 52 of the position adjustment erection member 50 is inserted toward approximately the center of the housing portion 12 of each receiving member 15 (15a, 15b).

[0087] Thus, as shown in Figure 8, when the insertion portion 52 of the position adjustment erection member 50 is inserted into the deepest part (inner bottom surface of the housing portion 12) of each receiving member 15 (15a, 15b), the receiving member 15b is positioned relative to the receiving member 15a. Figure 8 is a cross-sectional view partially showing the state in which the position adjustment erection member is inserted into a pair of receiving members of the precast concrete slab joint. As a result, the appropriate connection position of the precast RC slab 1b relative to the fixed precast RC slab 1a is achieved.

[0088] Furthermore, the receiving member 15b on the precast RC slab 1b side, which is to be adjusted in position, is displaced toward the receiving member 15a of the precast RC slab 1a by sliding as the guiding part 53 provided on the insertion part 52 of the position adjustment erection member 50 presses against the inclined guide surface 13.

[0089] Therefore, the receiving member 15b can be displaced in all directions, i.e., all directions in the XY plane, by the pressure of the guide portion 53, which has an inverted truncated cone shape, on the inclined guide surface 13 having a roughly C-shaped tapered surface of the insertion portion 52 of the position adjustment erection member 50. Furthermore, when the insertion portion 52 is fitted into the housing portion 12, each of the guide portions 53 provided at the lower end of the insertion portion 52 slides in contact with the inclined guide surface 13 provided near the upper end opening of the housing portion 12 of each receiving member 15 (15a, 15b) and is guided into the housing portion 12. At this time, the receiving member 15b moves in the XY plane, and while eliminating interference between the guide portion 53 and the inclined guide surface 13, it is displaced and positioned in the correct position relative to the receiving member 15a.

[0090] For example, as shown in Figure 9, if the position of the receiving member 15b relative to the receiving member 15a is shifted along the Y direction by a predetermined distance W from the proper connection position, the receiving member 15b and the precast RC slab 1b can be displaced to the proper position in the Y direction by inserting the position adjustment erection member 50 into each receiving member 15 (15a, 15b). Figure 9 is a plan view showing a pair of receiving members in a state shifted in the Y direction.

[0091] Specifically, when the guide portion 53 contacts the inclined guide surface 13 at a position biased to one side in the Y direction of the housing portion 12 of the receiving member 15b, the receiving member 15b is displaced in the Y direction together with the precast RC floor slab 1. Furthermore, when the insertion portion 52 is inserted to the innermost part of the receiving member 15b, the receiving member 15b is positioned at the correct connection position in the Y direction relative to the receiving member 15a, as shown in Figure 10. Figure 10 is a plan view showing a pair of receiving members that have been displaced and adjusted to the correct connection position.

[0092] Furthermore, even when connecting precast RC floor slabs 1 (1a, 1b) at the same height, and even when the receiving members 15 (15a, 15b) are located at different heights before connection, the receiving member 15b can be positioned at the same height as the receiving member 15a by inserting each insertion part 52 into the deepest part of the receiving part 12 of each receiving member 15 (15a, 15b).

[0093] Specifically, when each of the insertion portions 52 of the position adjustment erection member 50 is inserted into the housing portion 12 of each receiving member 15 (15a, 15b), and the flange nut 57 is rotated in the fastening direction, the receiving member 15b is pressed in the axial direction (Z direction) of the bolt 30 by either the pressing portion 56 or the position adjustment erection member 50.

[0094] For example, if the receiving member 15b is positioned above the receiving member 15a, the position adjustment erection member 50 presses the bottom of the housing section 12 downward. Also, if the receiving member 15b is positioned below the receiving member 15a, the pressing part 56 presses the lower end surface of the receiving member 15b upward. As a result, the receiving member 15b is displaced and positioned at the same height as the receiving member 15a.

[0095] As explained above, the positioning of each receiving member 15 (15a, 15b) by the position adjustment erection member 50 is effective in any of the X, Y, and Z directions. By simply inserting the position adjustment erection member 50 into each receiving member 15 (15a, 15b), the receiving member 15b can be relatively displaced to the appropriate connection position relative to the receiving member 15a.

[0096] Of course, it is desirable to insert the insertion portion 52 of the position adjustment erection member 50 all the way to the deepest part of each receiving member 15 (15a, 15b), but if the insertion portion 52 can be inserted to the extent that the position of each receiving member 15 (15a, 15b) can be positioned, it is possible to omit inserting the insertion portion 52 all the way to the deepest part of each receiving member 15 (15a, 15b).

[0097] Thus, the positioning of the opposing receiving members 15(15a,15b) by the position adjustment erection member 50 is performed only on the receiving members 15(15a,15b) that are facing each other at two locations along the Y direction of adjacent precast RC slabs 1(1a,1b). In other words, if the opposing receiving members 15(15a,15b) at both ends of the precast RC slab 1(1a,1b) are in the correct connection position, then the multiple receiving members 15(15a,15b) provided between the two receiving members 15(15a,15b) at both ends will also be in the correct connection position.

[0098] Furthermore, the position adjustment erection member 50 is removed from the opposing receiving members 15 (15a, 15b) after the receiving members 15 (15a, 15b) have been positioned. However, in some cases, the position adjustment erection member 50 may not be able to be removed from the pair of positioned receiving members 15 (15a, 15b).

[0099] In this case, the position adjustment mounting member 50 is fixed to each of the insertion parts 52 and each receiving member 15 (15a, 15b) by bolts 30. That is, bolts 30 are inserted through each of the holes 59 of each insertion part 52, and the male threaded parts 34 of each bolt 30 are screwed into the threaded holes 16 at the bottom of each of the housing parts 12 to fasten them.

[0100] Then, after the position adjustment erection member 50 connects each receiving member 15 (15a, 15b), the male threaded body 58 remains protruding above the upper surface of the precast RC floor slab 1 (1a, 1b) and therefore needs to be removed. In removing this male threaded body 58, first, a torque of a predetermined or greater value in the fastening direction is applied to the flange nut 57 to apply a torsional axial force of a predetermined or greater value to the male threaded body 58, causing the easily breakable portion 55b, which is pre-formed near the pressing portion 56, to break. In other words, the position adjustment erection member 50 constitutes a connecting member that connects each receiving member 15 (15a, 15b).

[0101] The male threaded body 58 can be separated from the pressing portion 56 and the shaft portion 31 by breaking the easily breakable portion 55b, and the shaft portion 31 can be removed together with the flange nut 57 by pulling it out from the position adjustment mounting member 50. Although the procedure is to fix the insertion portion 52 and each receiving member 15 (15a, 15b) with two bolts 30 before removing the male threaded body 58 and flange nut 57, it is also possible to break the easily breakable portion 55b of the male threaded body 58 to remove the male threaded body 58 and flange nut 57, and then fix the insertion portion 52 and each receiving member 15 (15a, 15b) with two bolts 30.

[0102] Furthermore, when removing the male threaded body 58 and flange nut 57 from the position adjustment erection member 50, the easily breakable portion 55b of the male threaded body 58 was broken, but this breakage is not a particularly essential process. For example, it is also possible to separate the flange nut 57 by rotating it in a direction that loosens it relative to the male threaded body 58, and then remove the male threaded body 58 by letting it fall from the position adjustment erection member 50.

[0103] Of course, if it is desired to maintain the state in which the male threaded body 58 is located between each receiving member 15 (15a, 15b), it goes without saying that the male threaded body 58 may be left inserted through the position adjustment erection member 50. In this case, the flange nut 57 may be left screwed onto the male threaded body 58, or it may be separated from the male threaded body 58 and removed.

[0104] Furthermore, when removing the position adjustment erection member 50 from each receiving member 15 (15a, 15b), it is not necessary to break the male threaded body 58, and the male threaded body 58 can be removed together with the position adjustment erection member 50. In this case, the flange nut 57 may remain screwed onto the male threaded body 58.

[0105] As explained above, even if each receiving member 15 (15a, 15b) of the joint 10 is misaligned in any direction (X, Y, or Z) from its predetermined position, the misalignment can be corrected and positioning completed simply by inserting the insertion portion 52 of the position adjustment erection member 50 into each receiving member 15 (15a, 15b) and fastening it with screws, for example, by rotating the flange nut 57 in the fastening direction. Therefore, positioning work becomes easier, the time required for proper placement of the deck slab is shortened, work efficiency is improved, and workability is greatly enhanced.

[0106] Furthermore, since the insertion portion 52 of the position adjustment erection member 50 fits into the housing portion 12, the positioning of each receiving member 15 (15a, 15b) can be adjusted. This allows for flexible error handling in response to dimensional deviations, positional deviations, deformations, etc. from the design drawings for each site, as well as distortions and twists of the precast RC floor slab, enabling construction with a high degree of freedom and significantly reducing the labor required for so-called on-site adjustment work.

[0107] In other words, if the insertion portion 53a, which forms the maximum outer diameter portion of the insertion portion 52, enters the housing portion 12, and the lower end of the guide portion 53 reaches the deepest part of the housing portion 12, the precast RC floor slabs 1 (1a, 1b) will be automatically positioned relative to each other in the X, Y, and Z directions. At this time, the insertion relief portion 52a does not come into contact with the inner circumferential surface of the housing portion 12, so by adjusting the height of the insertion relief portion 52a, it is possible to improve the fit between the insertion portion 52 and the housing portion 12.

[0108] Therefore, by setting the axial length of the insertion portion 53a along the Z direction to be short, even if the axes of the receiving portions 12 of each receiving member 15 (15a, 15b) are not parallel to each other due to distortion or twisting of the precast RC floor slab 1 (1a, 1b), the insertion portion 52 can be easily inserted into the receiving portion 12 while absorbing and forcing this parallel error.

[0109] Furthermore, the axial length of the insertion portion 53a may be extended in the Z direction to make it longer. Doing so has the effect of improving the coaxiality between the insertion portion 52 and the housing portion 12.

[0110] In this way, by using the position adjustment erection member 50, the joint 10 improves the workability of erecting precast RC deck slabs 1 (1a, 1b) such as road bridge decks. Even if there are large errors due to dimensional deviations, positional deviations, deformations, distortions, or twists of the road bridge deck from the design drawings at each site where the joining work is performed, these errors can be absorbed by so-called on-site adjustments at the site where the joining work is performed, allowing for flexible responses and a high degree of freedom in construction.

[0111] In addition, by using the position-adjusting erection member 50, the joint 10 significantly improves constructability and greatly reduces the time required for joining road bridge decks, while simultaneously enabling labor savings, shorter construction periods, increased strength, and greater durability.

[0112] Here, the dimensional relationships of each component of the joint 10 will be explained using Figure 11. Figure 11 is a cross-sectional view showing the dimensional relationships of the components of the precast concrete slab joint.

[0113] Each receiving member 15 (15a, 15b) has a female screw hole 16 formed at its bottom that is set to a screw depth S. The connecting member 20 has recesses 23 in each insertion portion 22 that are set to a depth D1 and hole lengths D2 in the holes 24. The bolt 30 has a shaft portion 31 with a shank length L1, a head portion 32 with an outward flange 33 that is set to a head height L2, and a male screw portion 34 that is set to a screw length L3. In other words, the length of the bolt 30 is L4 when the shank portion 31 is subtracted from the screw length L3.

[0114] The three stepped washers 40 are set such that one stepped washer 41 has a thickness T1, another stepped washer 42 has a thickness T2, and the remaining stepped washer 42 has a thickness T3.

[0115] The dimensions of the joint 10 are set such that the length L1 of the underside of the shaft portion 31 of the bolt 30 is longer than the length D2 of the hole portion 24 of the insertion portion 22 and the sum of the thicknesses T1, T2, T3 of the three stepped washers 40 (41, 42, 43) (T1 + T2 + T3) (D2 + T1 + T2 + T3) [L1 > (D2 + T1 + T2 + T3)].

[0116] As a result, even when the three stepped washers 40 (41, 42, 43) of the bolt 30 are fitted between the head 32 and the inner bottom surface of the recess 23 which serves as the upper end surface of the insertion portion 22 and / or between the lower end surface of the insertion portion 22 and each receiving member 15 (15a, 15b), the male threaded portion 34 emerges from the hole 24 of the insertion portion 22 and is screwed into the female threaded holes 16 of each receiving member 15 (15a, 15b).

[0117] Furthermore, the dimensions of the joint 10 are set such that the length L1 of the underside of the shaft portion 31 of the bolt 30 is less than or equal to the length D2 of the hole 24 of the insertion portion 22, the thread depth S of the female threaded holes 16 of each receiving member 15 (15a, 15b), and the sum of the thicknesses T1, T2, T3 of the three stepped washers 40 (41, 42, 43) (D2 + S + T1 + T2 + T3) [L1 ≤ (D2 + S + T1 + T2 + T3)].

[0118] As a result, the bolt 30 does not protrude beyond the female threaded hole 16 of each receiving member 15 (15a, 15b) into which the male threaded portion 34 leading out from the hole 24 of the insertion portion 22 is screwed. In other words, the bolt 30 is prevented from having its shaft portion 31 protrude from the lower end surface of each receiving member 15 (15a, 15b) and damage the precast RC floor slab 1 (1a, 1b).

[0119] Furthermore, the length L4 of the shaft portion 31 of the bolt 30 is the length L1 minus the thread length L3, and the dimensions of each are set such that this length L4 is less than or equal to the sum of the hole length D2 of the hole portion 24 of the insertion portion 22 and the total thickness (T1+T2+T3) of the three stepped washers 40 (41, 42, 43) (D2+T1+T2+T3) [L4≦(D2+T1+T2+T3)].

[0120] Furthermore, the joint 10 is configured such that the thread length L3 of the male threaded portion 34 of the bolt 30 is greater than or equal to the thread depth S of the female threaded hole 16 of each receiving member 15 (15a, 15b) (L3 ≥ S). This ensures that the bolt 30 has sufficient threading length (threading amount) of the male threaded portion 34 relative to the female threaded hole 16.

[0121] Furthermore, it is preferable to set the dimensions of the joint 10 such that the depth D1 of the recess 23 of each insertion part 22 is greater than or equal to the sum of the height L2 of the head 32 of the bolt 30 and the total thickness (T1+T2+T3) of the three stepped washers 40 (41, 42, 43) (D1≧(L2+T1+T2+T3)). This ensures that the head 32 of the bolt 30 does not protrude from the upper surface of each insertion part 22, but is housed within the surrounding recess 23.

[0122] As shown in Figure 12, the joint 10 configured as described above has a connecting member 20 inserted into a plurality of opposing receiving members 15 (15a, 15b) that have been adjusted to the appropriate connection position by the position adjustment erection member 50. Figure 12 is an exploded perspective view showing the state in which the connecting member is inserted into the opposing receiving members of the precast concrete slab joint.

[0123] Then, as shown in Figure 13, the joint 10 is fastened to each receiving member 15 (15a, 15b) by inserting bolts 30 into the holes 24 of each insertion portion 22 of the connecting member 20. Figure 13 is an exploded perspective view showing the state in which bolts are fastened to the connecting member that is inserted into a pair of receiving members of the precast concrete slab joint.

[0124] As shown in Figure 14, when the faces of the precast RC slabs 1 (1a, 1b) are at the same height, the joint 10 is installed so that three stepped washers 40 (41, 42, 43) overlap the recesses 23 of each insertion part 22, and then the bolts 30 are fastened. Figure 14 is a cross-sectional view showing a precast concrete slab joint with the faces of the precast RC slabs at the same height.

[0125] In other words, the three stepped washers 40 (41, 42, 43) are arranged overlapping in the respective recesses 23 of each insertion portion 22, and the bolt 30 is inserted. Therefore, the three stepped washers 40 (41, 42, 43) are sandwiched between the inner bottom surface of the recess 23, which serves as the upper end surface of the insertion portion 22, and the head 32 of the bolt 30, which is provided with the outward-facing flange 33.

[0126] Furthermore, even if the height of the joint 10 is adjusted using adjustment bolts (not shown) on the precast RC slab 1 (1a, 1b), differences in height may occur where the surface positions of the precast RC slab 1 (1a, 1b) are at different heights due to product tolerances, construction errors, twisting due to curved sections, deflection of the main girder 100 and / or the steel bridge pier itself (not shown), deflection due to bridge deck load, deflection of the main girder 100 due to temporary structures, etc.

[0127] If a step occurs in the precast RC floor slabs 1 (1a, 1b) connected in this manner, the joint 10 can fasten the lower end surfaces of the connecting members 20 that are inserted into the opposing receiving members 15 (15a, 15b) without any gaps by appropriately changing the number of stepped washers 40 (41, 42, 43) placed in the recesses 23 of each insertion portion 22 of the connecting member 20 and the inner bottom of the housing portion 12 of each receiving member 15 (15a, 15b) according to the step.

[0128] Specifically, as shown in Figure 15, if, for example, the planar position of a displaceable precast concrete slab 1b is lower in the Z direction than the planar position of a precast concrete slab 1a that has already been fixed on a plurality of main girders 100 by a positioning process, a step-adjusting washer 41 having a thickness T1 (≒H1) approximately the same as this height difference H1 is selectively placed on the receiving member 15b, and then the connecting member 20 is inserted into the receiving member 15 (15a, 15b). Figure 15 is a cross-sectional view showing a precast concrete slab joint to illustrate the state in which the connecting member is fastened to the receiving member where a step has occurred.

[0129] In other words, in the joint 10, stepped washers 41 of approximately the same thickness are selectively placed at the inner bottom of the housing portion 12 of the receiving member 15b, which is located at the lower position among the receiving members 15 (15a, 15b), in order to fill the height difference H1. The thicknesses (T1, T2, T3) of the multiple stepped washers 40 (41, 42, 43) may be adjusted by adjusting the thickness of one washer to match the height difference H1, or the combined thickness of the multiple stepped washers 40 (41, 42, 43) stacked together may be adjusted to match the height difference H1.

[0130] In the receiving member 15a, the lower end surface of the insertion portion 22 of the connecting member 20 abuts against the inner bottom of the housing portion 12. In the receiving portion 12, the lower end surface of the insertion portion 22 of the connecting member 20 abuts against the stepped washer 41 disposed on the inner bottom surface of the housing portion 12. That is, the stepped washer 41 is sandwiched between the lower end surface of the insertion portion 22 and the inner bottom surface of the housing portion 12.

[0131] Furthermore, of the insertion portions 22 of the connecting member 20, two stepped washers 42 and 43 are superimposed in the recess 23 on the receiving member 15b side provided in the precast RC floor slab 1b. On the other hand, of the insertion portions 22 of the connecting member 20, three stepped washers 40 (41, 42, 43) are superimposed in the recess 23 on the receiving member 15a side provided in the precast RC floor slab 1a.

[0132] In this state, the joint 10 is fastened and secured by bolts 30 to the connecting member 20 and each receiving member 15 (15a, 15b), as shown in Figure 16. In order to fasten the connecting member 20 and each receiving member 15 (15a, 15b) with bolts 30, the bolts 30 are inserted through each stepped washer 40 (41, 42, 43) and the hole 24 of the insertion part 22, and the male threaded part 34 of the bolt 30 is screwed into the female threaded hole 16 to fasten them. Figure 16 is a cross-sectional view showing a precast concrete slab joint in which the connecting member is fastened to the receiving member where a step has occurred.

[0133] As a result, the joint 10 is configured such that the receiving member 15b is positioned below the receiving member 15a with a height difference H1 in the Z direction equal to the thickness T1 of the stepped washer 41, and the receiving members 15 (15a, 15b) are connected by the connecting member 20.

[0134] Thus, when the receiving member 15b is positioned lower than the receiving member 15a, creating a step difference of H1, the lower end surface of the insertion portion 22 on the receiving member 15b side of the connecting member 20 abuts against the stepped washer 41. Therefore, the connecting member 20 is fastened to the receiving member 15b without any gaps through the stepped washer 41, with the lower end surface of the insertion portion 22 on the receiving member 15b side facing the receiving member 15b. Furthermore, the connecting member 20 is fastened with the lower end surface of the insertion portion 22 on the receiving member 15a side directly abutting against the inner bottom of the receiving member 15a without any gaps.

[0135] Furthermore, as shown in Figure 17, if, for example, the planar position of the precast RC slab 1b is lower in the Z direction than the planar position of the precast RC slab 1a, a step difference of H2 occurs, all three stepped washers 40 (41, 42, 43) are selectively placed at the inner bottom of the receiving portion 12 of the receiving member 15b to fill this height difference H2. Figure 17 is a cross-sectional view showing a precast concrete slab joint in which a connecting member is fastened to a receiving member where a step difference with a different height difference than that in Figure 16 occurs.

[0136] Here, the height difference H2 is approximately the same as the sum of the thicknesses T1, T2, and T3 of the three stepped washers 40 (41, 42, 43) (T1 + T2 + T3) (H2 ≈ T1 + T2 + T3). In this way, the joint 10 can be configured to fill the height difference by appropriately and selectively combining the number of the three stepped washers 40 (41, 42, 43) according to the height difference of the step between the planar position of the precast RC floor slab 1b and the planar position of the precast RC floor slab 1a.

[0137] Furthermore, even when there is a difference in height between the precast RC floor slabs 1 (1a, 1b) to be connected, the joint 10 can appropriately and selectively interpose multiple stepped washers 40 (41, 42, 43) according to the height difference, thereby making the screw-in length (thickness) of the male threaded portions 34 of the two bolts 30 that fasten the connecting member 20 constant when screwed into the female threaded holes 16 of each receiving member 15 (15a, 15b).

[0138] In other words, even if the number of stepped washers 40 (41, 42, 43) interposed in the recesses 23 of each insertion portion 22 of the connecting member 20 differs from the number of stepped washers interposed between the inner bottom of each receiving member 15 (15a, 15b) and the lower end surface of each insertion portion 22, the hole length D2 of the hole portion 24 of the insertion portion 22 and the sum of the thicknesses T1 and T2 of the three stepped washers 40 (41, 42, 43) (D2 + T1 + T2 + T3) remain unchanged.

[0139] Since this total dimension (D2+T1+T2+T3) is smaller (shorter) than the length L1 of the shaft portion 31 of the bolt 30 [L1>(D2+T1+T2+T3)], the amount of protrusion of the male threaded portion 34 of the bolt 30 becomes constant. As a result, when the two bolts 30 fasten each insertion portion 22 of the connecting member 20 to each receiving member 15 (15a, 15b), the screw-in length (threading amount) of each male threaded portion 34 that screws into each female threaded hole 16 becomes constant.

[0140] Furthermore, after the precast RC floor slabs 1 (1a, 1b) are connected by joints 10, a curable fluid such as mortar or grout is injected into the recesses 2 (2a, 2b) and the gaps in the joints. The curable fluid may be gypsum, ready-mix concrete, water glass, or a thermosetting or thermoplastic synthetic resin in a fluid state.

[0141] In this way, by injecting a hardening fluid into the recesses 2 (2a, 2b) and gaps in the joints of the precast RC floor slab 1 (1a, 1b) and allowing it to harden, the connecting member 20 and each receiving member 15 (15a, 15b) can be fixed more firmly, and the rigid connection between each receiving member 15 (15a, 15b) and the connecting member 20 can be increased, as well as fatigue resistance can be improved.

[0142] Furthermore, the hardening fluid can be injected into all gaps between the precast RC floor slabs 1 (1a, 1b), thereby further strengthening the connection between the precast RC floor slabs 1 (1a, 1b).

[0143] Furthermore, the number of receiving members 15(15a,15b) that are positioned on and facing the precast RC floor slab 1(1a,1b) is not particularly limited and can be appropriately set depending on the size of the precast RC floor slab 1(1a,1b), etc.

[0144] Furthermore, when positioning the precast RC slab 1 (1a, 1b) with multiple joints 10, the positioning order can be set as appropriate. For example, the positioning may be performed sequentially from one end of the precast RC slab 1 (1a, 1b) toward the other end, or sequentially from an intermediate position toward the end, or the system may be configured to position only other appropriate parts. Alternatively, the positioning may be performed from both ends toward the intermediate position almost simultaneously or alternately.

[0145] As described above, in this embodiment, when installing precast RC slabs 1 (1a, 1b) onto the main girder 100, even if there is a step in the height direction perpendicular to the longitudinal direction of the main girder 100 at the joint portion of adjacent precast PC slabs 1 (1a, 1b), by appropriately interposing multiple step washers 40 (41, 42, 43) between the receiving member 15 (15a, 15b) and / or connecting member 20, the screw-in length (thickness) of the male threaded portion 34 that engages with each female threaded hole 16 can be made uniform without variation when using bolts 30 of the same standard, by appropriately interposing multiple step washers 40 (41, 42, 43) between the receiving member 15 (15a, 15b) and / or connecting member 20.

[0146] In other words, when the joint 10 fixes the connecting member 20, which is inserted into the two receiving members 15 (15a, 15b), with two bolts 30, the screw-in depth of each bolt is equal. Therefore, there is no difference in the axial force of the bolts 30 that fasten the precast PC floor slabs 1 (1a, 1b) together, and the fastening force at the joint between the floor slabs, which is subjected to vibrations when vehicles or the like are running, can be made equal.

[0147] Furthermore, the joint 10 does not require the use of bolts of different lengths to fasten the joint portion so that the threaded length (threading amount) of the bolts 30 is equal, as in conventional methods, nor does it require the preparation of bolts of different specifications with different thread lengths according to the height difference of the step. Therefore, the joint 10 can suppress construction defects caused by selecting the wrong bolt 30. Moreover, since the joint 10 uses two bolts 30 of the same specification underhead length L1, the tips of the male threaded portions 34 of the bolts 30 do not protrude from the back (bottom) surfaces of the two receiving members 15 (15a, 15b). As a result, the precast PC floor slabs 1 (1a, 1b) covering the back (bottom) surfaces of the two receiving members 15 (15a, 15b) are not pushed and destroyed, nor do they peel off. In this way, the joint 10 can also prevent construction defects.

[0148] As described above, the precast concrete slab joint 10 is configured such that even if there is a step difference between adjacent precast PC slabs 1 (1a, 1b) when installing it on the main girder 100, the joint portion can be fastened with bolts 30 of the same standard so that the screw-in length (threading amount) is uniform, thereby preventing construction defects.

[0149] (First variation) As shown in Figure 18, the joint 10 of this modified example does not have recesses 23 in each insertion portion 22 of the connecting member 20, and has an upper end surface 22a formed with a step of a predetermined height on the lower end side along the Z direction. Figure 18 is an exploded perspective view showing the configuration of a precast concrete slab joint connecting adjacent precast RC slabs of the first modified example.

[0150] The upper end surface 22a of each insertion portion 22 is substantially circular in shape and has an opening of a through hole 24 in the center. Thus, because the upper end surface 22a and lower end surface 22b of each insertion portion 22 of the connecting member 20 are circular in shape, each stepped washer 40 (41, 42, 43) can be made to be approximately the same size as the diameter of the upper end surface 22a and lower end surface 22b. Furthermore, considering the ease of installation on the inner bottom surface of the receiving member 15 (15a, 15b), it is preferable that each stepped washer 40 (41, 42, 43) has a diameter slightly smaller than the diameter of the upper end surface 22a and lower end surface 22b.

[0151] In this configuration, when the stepped washers 40 (41, 42, 43) are installed on the inner bottom surface of the receiving member 15 (15a, 15b), the contact area of ​​the stepped washers 40 (41, 42, 43) sandwiched between the inner bottom surface of the receiving member 15 (15a, 15b) and the lower end surface 22b of the insertion part 22 is increased. As a result, the joint 10 can stably fasten the connecting member 20 to the receiving member 15 (15a, 15b) even when there is a step difference in the precast RC floor slabs 1 (1a, 1b) being connected.

[0152] (Second variation) Furthermore, as shown in Figures 19 and 20, the joint 10 is configured such that an H-shaped cotter 120 is inserted into two well-known opposing C-shaped joint fittings 110 (110a, 110b), and the H-shaped cotter 120 is fastened to each C-shaped joint fitting 110 (110a, 110b) with two bolts 30. Multiple stepped washers 40 (41, 42, 43), in this case three on each side as a set of six, can be applied. Figure 19 is an exploded perspective view showing an example of a precast concrete slab joint consisting of well-known C-shaped joint fittings and H-shaped cotters for connecting adjacent precast RC slabs, and Figure 20 is an exploded perspective view showing another example of a precast concrete slab joint consisting of well-known C-shaped joint fittings and H-shaped cotters for connecting adjacent precast RC slabs.

[0153] Each stepped washer 40 (41, 42, 43) here is rectangular in shape as shown in Figure 19 or circular ring in shape as shown in Figure 20, to match the shape of the inner bottom of each C-type joint fitting 110 (110a, 110b) and the H-shaped cotter 120. Each stepped washer 40 (41, 42, 43) here only needs to have a shape that allows at least the bolt 30 to be inserted and can support the H-shaped cotter 120. For example, it may be a flat washer shape, a spring washer shape, a disc spring washer shape, a toothed washer shape, a spherical washer shape, etc.

[0154] (Third variation) Furthermore, the joint 10 can be applied in various shapes as shown in Figure 21, for the configuration of the intermediate connecting portion 141 of the cotter 140 that is inserted into opposing C-type joint fittings 130 (130a, 130b). Figure 21 is a plan view showing a precast concrete slab joint, where Figure 21(a) illustrates a cotter with an H-shaped intermediate connecting portion, Figure 21(b) illustrates a cotter with an intermediate connecting portion in which the flanges are connected by two webs, and Figure 21(c) illustrates a cotter with a rectangular O-shaped intermediate connecting portion.

[0155] For example, the joint 10 shown in Figure 21(a) has a configuration in which the web 142 of the intermediate connecting portion 141 has a concave curved portion with a circular arc cross-section. Also, for example, the joint 10 shown in Figure 21(b) has a configuration in which two webs 142 have an intermediate connecting portion 141 spaced a predetermined distance apart. Furthermore, for example, the joint 10 shown in Figure 21(c) has a configuration in which the intermediate connecting portion 141 has a rectangular O-shape.

[0156] (Fourth variation) Furthermore, the joint 10 can be adapted to various shapes as shown in Figure 22, for the configuration of the two insertion parts 147, 148, and 149 of the H-shaped cotter 145 that are inserted into opposing C-shaped joint fittings 130 (130a, 130b). Figure 22 is a plan view showing a precast concrete slab joint, where Figure 22(a) illustrates an H-shaped cotter having a pair of rectangular insertion parts in plan view, Figure 22(b) illustrates an H-shaped cotter having a pair of trapezoidal insertion parts in plan view, and Figure 22(c) illustrates an H-shaped cotter having a pair of triangular insertion parts in plan view.

[0157] For example, the joint 10 shown in Figure 22(a) has a configuration in which the two insertion portions 147 of the H-shaped cotter 145 form a rectangular shape in plan view. In addition, the joint 10 has each housing portion 131 of the C-shaped joint fitting 130 (130a, 130b) into which each insertion portion 147 is inserted, forming a rectangular recess in plan view to match each insertion portion 147.

[0158] Furthermore, for example, the joint 10 shown in Figure 22(b) is composed of two insertion parts 148 of an H-shaped cotter 145. In addition, the joint 10 has a C-shaped joint fitting 130 (130a, 130b) into which each insertion part 148 is inserted, and each receiving part 132 forms a trapezoidal recess in plan view to match each insertion part 148.

[0159] Furthermore, for example, the joint 10 shown in Figure 22(c) has a configuration in which the two insertion portions 149 of the H-shaped cotter 145 form a triangular shape in plan view. In addition, the joint 10 has a configuration in which the respective receiving portions 133 of the C-shaped joint fittings 130 (130a, 130b) into which each insertion portion 149 is inserted form a triangular recess in plan view to match the respective insertion portion 148. In this case, the C-shaped joint fittings 130 (130a, 130b) are approximately triangular in plan view to match the shape of the two insertion portions 149.

[0160] The invention described in the above embodiments is not limited to those embodiments and their respective modifications, and various modifications can be made in the implementation stage without departing from the gist of the invention. Furthermore, the above embodiments and their respective modifications include inventions at various stages, and various inventions can be extracted by appropriate combinations of the multiple constituent elements disclosed.

[0161] For example, if the problem described can be solved and the effects described can be obtained even if some of the constituent elements shown in the embodiment are deleted, then the configuration with the deleted constituent elements can be extracted as an invention. [Explanation of Symbols]

[0162] 1(1a,1b)...Precast RC floor slab 2(2a,2b)...recess 10…Precast concrete slab joint 11... Anchor 12...Detention Unit 13…Slope guideway 14…Connecting member insertion part 15(15a,15b)...Receiving member 16...hole 17…Regulatory recess 18…Regulatory Department 20…Connecting member 21…Bridge portion 22... Insertion part 22a…Top end surface 22b…Lower end surface 23…recess 24...hole 30... Volts 31... Shaft 32...Head 33… Outward flange 34... Threaded part 40 (41, 42, 43)... Step washers 50... Position adjustment erection member 51…Bridge portion 52... Insertion part 52a...Escape Club 53…Guiding part 53a...Insertion part 54…recess 55a...Spiral groove 55b…Easy breakage part 56...Pressing part 57…Flange nut 58... Male screw body 59…Through hole 100…Main digit

Claims

1. A precast concrete slab joint that connects adjacent precast concrete slabs, comprising a receiving member positioned on the precast concrete slab and a connecting member that spans and connects a pair of opposing receiving members, Each of the above receiving members has a receiving portion into which the above connecting member is inserted, The above-mentioned connecting member has a pair of insertion parts that are inserted into the respective housing parts of the above-mentioned receiving member, and a bridging part that connects the insertion parts. A bolt fastens each of the above insertion parts to the above receiving member, Each of the above-mentioned housing sections has a bottomed section formed with a female threaded hole into which the male threaded portion of the bolt is screwed, A stepped washer is provided which abuts against the upper and / or lower end surfaces of the respective insertion parts and is selectively positioned between the head of the bolt and / or between the insertion part and the bottomed part according to the height difference of the pair of receiving members, thereby making the amount of screwing of the male threaded portion of the bolt into the female threaded hole constant and uniform. A precast concrete slab joint characterized by having the following features.

2. The precast concrete slab joint according to claim 1, characterized in that a plurality of the stepped washers are provided in each of the pair of insertion portions.

3. The above-mentioned insertion portion has a hole through which the bolt is inserted, The precast concrete slab joint according to claim 1, characterized in that the length of the shank portion of the bolt on which the male thread portion is formed is set to be longer than the sum of the length of the hole portion and the thickness of the stepped washer.

4. The precast concrete slab joint according to claim 3, characterized in that the length of the shaft portion on which the male thread portion is formed is set to be less than or equal to the sum of the length of the hole portion, the thickness of the stepped washer, and the depth of the female thread hole.

5. Each of the above insertion portions has a recess at its upper part that can be arranged to surround the head of the bolt and the stepped washer. The precast concrete slab joint according to claim 1, characterized in that the depth of the recess is set to be greater than or equal to the sum of the height of the head and the thickness of the stepped washer.

6. The precast concrete slab joint according to claim 5, characterized in that the inner bottom surface of the recess constitutes the upper end surface of the insertion portion.

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