Joint structure, and floor slab connection method

Abstract

To provide a joint structure capable of reducing the joint width compared to conventional technology to solve the problems of conventional technology, and a floor slab connection method.SOLUTION: A disclosed joint structure is a joint structure for connecting precast steel-concrete composite decks consisting of a bottom steel plate and a concrete deck in the first axis direction, which includes multiple lower and upper connectors. Adjacent steel-concrete composite decks are connected by fastening the lower and upper connecting members after the lower and upper connecting members are inserted into the slits of the end connecting plates of the adjacent steel-concrete composite deck slabs, and after placing the gap spacer in the joint.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a technology related to a precast steel-concrete composite deck consisting of a bottom steel plate and a concrete deck. More specifically, it relates to a joint structure connected by bolts or the like installed in the slits of opposing plates, and a method for connecting steel-concrete composite decks using this joint structure. [Background technology]

[0002] It has been pointed out that the construction infrastructure (hereafter referred to as "construction infrastructure"), which was developed intensively during the period of high economic growth, is already showing signs of considerable deterioration. In 2014, the Council for Social Capital Development compiled a "Recommendation for Full-scale Implementation of Measures to Counteract Aging Roads," which cited the Sasago Tunnel ceiling collapse accident of 2012 as an example, sounding the alarm that "in the near future, this will lead to fatal incidents, such as the collapse of bridges, affecting human lives and social infrastructure," and strongly advocated the importance of maintaining and managing construction infrastructure.

[0003] Against this background, the government has promulgated a ministerial ordinance amending part of the Road Act Enforcement Regulations, formulating periodic inspection guidelines that outline specific construction infrastructure inspection methods, areas to look out for in major abnormalities, and photographs of case studies. These periodic inspection guidelines apply to bridges with a length of 2.0m or more, which is said to number around 700,000, and stipulate that the first inspection should be carried out within two years of opening to service, with periodic inspections thereafter to be carried out once every five years.

[0004] Meanwhile, the "Highway Bridge Specifications," which are the standards for designing road bridges, have been revised from time to time since the draft of the Steel Highway Bridge Design Specifications was published in 1939, and were significantly revised in particular after the Hyogo-ken Nanbu Earthquake. As a result, there are many cases where bridges that previously had sufficient strength are found to have insufficient strength in light of current design standards.

[0005] Due to the two reasons mentioned above, namely deterioration and insufficient strength, bridges are now frequently reinforced or rebuilt. Furthermore, even if the girder members are sound, if the deck that supports the vehicle load deteriorates, the deck is repaired or deck renewal work is carried out to replace the deteriorated deck with a new one.

[0006] However, current road bridges ensure a large volume of traffic, meaning they support the movement of people and the distribution industry, and so cannot be easily taken out of service. In particular, viaducts for expressways and other roads exclusively for automobiles carry tens of thousands of vehicles per day, and if they were to be closed to traffic, the economic losses would be immeasurable, and if emergency patients could not be transported, it could become a social problem. For this reason, when construction is carried out on a road bridge that is in service, it is always necessary to reopen it to traffic as soon as possible, and contractors are working hard to shorten the construction period in order to achieve this.

[0007] Traditionally, the cast-in-place concrete method has been used to construct concrete decks. This method requires assembling formwork on-site, pouring fresh concrete, and then allowing it to cure for a specified period of time. This means that the site is occupied for a long period of time, and when replacing the deck of a road bridge in service, traffic is restricted for an equally long period of time.

[0008] Therefore, in recent years, there has been an increase in the use of precast concrete decks (hereinafter simply referred to as "precast decks") instead of cast-in-place concrete construction methods. Because precast decks are manufactured in factories, quality control is easy, and what's more, the on-site process is mainly installation, which means that the time required for construction on-site can be shortened.

[0009] Well-known precast decks include steel-concrete composite decks, PC (Prestressed Concrete) decks, and RC (Reinforced Concrete) decks. Among these, steel-concrete composite decks are primarily composite structures consisting of a base steel plate and a concrete deck, with the base steel plate functioning as a structural member bearing cross-sectional forces. Because the structure effectively combines steel members that bear tensile forces and concrete that bear compressive forces, the deck is highly rigid and can accommodate long spans. Furthermore, the base steel plate of a steel-concrete composite deck functions as a formwork until the concrete hardens, and the steel plate, reinforced with vertical ribs, acts as a self-supporting support, eliminating some of the work required for formwork, making it an excellent structure in terms of construction (manufacturing).

[0010] With regard to steel-concrete composite decks, which have many advantages, various improvement techniques have been proposed. In particular, the applicant of the present application has proposed various techniques for steel-concrete composite decks, as shown in Patent Document 1, for example. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-270270 Summary of the Invention [Problem to be solved by the invention]

[0012] The technology disclosed in Patent Document 1 is a steel-concrete composite deck using a steel deck consisting of a bottom steel plate and vertical ribs, with multiple through-holes in the vertical ribs to increase adhesion to the concrete, and the vertical ribs positioned and fixed in the direction of the main girders to prevent buckling of the bottom steel plate. The steel-concrete composite deck according to Patent Document 1 can be constructed using a cast-in-place concrete method, or can be manufactured as a precast product in a factory.

[0013] When installing precast deck slabs on site, multiple precast deck slabs are placed in their designated positions, and gaps (joints) are formed between adjacent precast deck slabs. For example, in the case of a road bridge, if the bridge is divided in the direction of the road width (perpendicular to the bridge axis), a "vertical joint" extending in the direction of the bridge axis is formed, and if the bridge is divided in the direction of travel (the direction of the bridge axis), a "horizontal joint" extending in the direction perpendicular to the bridge axis is formed. Adjacent precast deck slabs are then connected at these joints, and the means for connecting them is called a "joint."

[0014] Typically, filler concrete or mortar is poured into the joints. In other words, precast decks are used to speed up on-site construction, but the traditional cast-in-place concrete method is used for the joints. Therefore, in order to speed up on-site construction, it is desirable to reduce the amount of work required for the joints, that is, the amount of filler concrete poured, and therefore it is desirable to keep the joint width as small as possible. Furthermore, if the joint width is large, the space available for construction (work space) is reduced accordingly, and if part of the road is opened to the public, the width of the road will also be limited, so in this respect it is also desirable to keep the joint width as small as possible.

[0015] When installing precast steel-concrete composite decks, joints using splice plates are common. Specifically, splice plates placed below adjacent steel-concrete composite decks are joined to the bottom steel plates of both decks with bolts or other means, and then concrete is poured into the gap. This method requires a certain amount of clearance in addition to the width of the splice plates, which means that a corresponding joint width is required. Therefore, conventional methods for installing precast steel-concrete composite decks tend to result in relatively large joint widths, and therefore a technology that can reduce joint widths was needed.

[0016] The object of the present invention is to solve the problems associated with the prior art, that is, to provide a joint structure and a deck slab connecting method that can reduce the joint width compared to the prior art. [Means for solving the problem]

[0017] The present invention was made by focusing on the point that a slit is made in a plate material erected on a bottom steel plate, and a bolt or the like is hung across the plate material arranged opposite to connect them, and is an invention based on an idea that has not been seen in the past.

[0018] The joint structure of the present invention is a joint structure that connects precast steel-concrete composite decks made of bottom steel plates and deck concrete in a first axis direction, and includes multiple lower connecting members and upper connecting members. The precast steel-concrete composite decks that the present invention targets have the following characteristics: An "end connecting plate" is fixed to the end of the bottom steel plate in the first axis direction. The end connecting plate is approximately perpendicular (including perpendicular) to the bottom steel plate and is arranged in a second axis direction (perpendicular or diagonal to the first axis direction), and multiple "slits" are formed in the end connecting plate along the second axis direction. When the bottom steel plate is arranged approximately horizontally (including horizontally), the slits are strip-shaped holes that open at the top of the end connecting plate. The rod-shaped lower connecting members that make up the joint structure of the present invention are inserted into the slits, and the rod-shaped upper connecting members are arranged above the lower connecting members and inserted into the slits. Then, the lower connecting member and the upper connecting member are inserted into the slits of the end connecting plates of adjacent steel-concrete composite decks, and these lower connecting members and upper connecting members are tightened to connect adjacent steel-concrete composite decks.

[0019] The joint structure of the present invention can also be equipped with a gap spacer. This gap spacer has a thickness equivalent to the width of the joint formed where the end connecting plates of adjacent steel-concrete composite decks face each other. In this case, the adjacent steel-concrete composite decks are connected by placing the gap spacer in the joint and then tightening the lower connecting member and the upper connecting member.

[0020] The joint structure of the present invention can also be one in which the cross-sectional diameter of the upper connecting member is larger than the cross-sectional diameter of the lower connecting member. In this case, the slit includes an upper housing hole formed in the opening to house the upper connecting member, and a lower housing groove communicating with the upper housing hole, the lower housing groove being narrower than the cross-sectional diameter of the upper connecting member. The lower connecting member inserted by dropping it from above the slit rests on the bottom of the lower housing groove, and the upper connecting member inserted by dropping it from above the slit rests on the upper housing hole.

[0021] In the joint structure of the present invention, the gap spacers may also include a lower gap spacer and an upper gap spacer. Two or more lower cutouts that accommodate the upper parts of the lower connecting members are formed on the lower surface of the lower gap spacer that is arranged above the lower connecting members, and two or more upper cutouts that accommodate the upper parts of the upper connecting members are formed on the lower surface of the upper gap spacer that is arranged above the upper connecting members. In this case, the lower gap spacers are arranged so that the lower cutouts accommodate the upper parts of two or more lower connecting members that are lined up in the second axial direction, and the upper gap spacers are arranged so that the upper cutouts accommodate the upper parts of two or more upper connecting members that are lined up in the second axial direction.

[0022] The joint structure of the present invention can also be one in which lower notches and upper notches are formed in the gap spacer. Specifically, one or more lower notches that accommodate the upper parts of the lower connecting members are formed in the lower surface of the gap spacer, and one or more upper notches that accommodate the lower parts of the upper connecting members are formed in the upper surface of the gap spacer. In this case, the gap spacer is arranged so that the lower notches accommodate the upper parts of one lower connecting member or two or more lower connecting members lined up in the second axial direction, and the upper notches accommodate the lower parts of one upper connecting member or two or more upper connecting members lined up in the second axial direction.

[0023] The joint structure of the present invention can also be one in which the gap spacers are wedge-shaped with inclined surfaces. In this case, the gap spacers are arranged in lower and upper rows to avoid the lower and upper connecting members in the joint, with the lower row gap spacers arranged so that their inclined surfaces taper upward, and the upper row gap spacers arranged so that their inclined surfaces taper downward and abut against each other. Alternatively, gap spacers (lower and upper connecting members) with slits can be arranged in the joint where the lower and upper connecting members are located.

[0024] The joint structure of the present invention can also have a plurality of reinforcing bar accommodating holes formed in the end connecting plate. These reinforcing bar accommodating holes are aligned in the second axial direction and are formed so that the top of the end connecting plate is open when the bottom steel plate is placed approximately horizontally (including horizontally). In this case, the first reinforcing bar arranged in the first axial direction in the slab concrete protrudes from the end connecting plate in the first axial direction, and a portion of it is placed in the reinforcing bar accommodating hole. Then, this first reinforcing bar is fastened using a threaded portion provided on the first reinforcing bar protruding from the end connecting plate.

[0025] The deck slab connecting method of the present invention is a method for connecting precast steel-concrete composite decks consisting of bottom steel plates and concrete decks, and includes a steel-concrete composite deck slab installation step, a lower connector installation step, an upper connector installation step, and a connector tightening step. In the steel-concrete composite deck slab installation step, one steel-concrete composite deck slab is installed adjacent to the other steel-concrete composite deck slab. In the lower connector installation step, a lower connector is inserted into the slit related to the end connector plate of one steel-concrete composite deck slab, while a lower connector is inserted into the slit related to the end connector plate of the other steel-concrete composite deck slab. In the upper connector installation step, an upper connector is inserted into the slit related to the end connector plate of one steel-concrete composite deck slab, while an upper connector is inserted into the slit related to the end connector plate of the other steel-concrete composite deck slab. Then, in the connector tightening step, the lower and upper connectors inserted into the slits are tightened.

[0026] The deck slab connecting method of the present invention can also be a method further comprising a gap spacer placement step of placing gap spacers in the joints. In this case, in the connector tightening step, the gap spacers are placed in the joints, and then the lower connector and the upper connector inserted into the slits are tightened.

[0027] The deck slab connecting method of the present invention may further include a joint filling step in which mortar or concrete is poured into the joints. In this case, the joint filling step is performed after the connecting material tightening step.

[0028] The deck connecting method of the present invention can also be a method that further includes a joint filling process and a box-opening process. In this box-opening process, mortar is poured into the box-opening section where the deck concrete has been boxed out so as to include the slits in the end connecting plate. In this case, the connector tightening process is performed after the mortar and concrete poured in the joint filling process have hardened, and the box-opening section is used to tighten the lower connector and the upper connector. [Effects of the Invention]

[0029] The joint structure and deck slab connecting method of the present invention have the following effects. (1) The joint width can be made smaller than in conventional techniques, which results in faster on-site construction. (2) Since the joint width can be reduced, a larger working space can be secured, and the width of the road open to the public can also be set wider. (3) Axial force can be applied by using high-strength bolts as the lower and upper connecting members and controlling the torque when tightening them. Furthermore, by filling the joints with mortar after installing the high-strength bolts and then applying axial force to the high-strength bolts after it has hardened, cracking of the mortar can be prevented and the strength of the joint can be further improved. (4) If the reinforcing bars in the concrete deck are fixed to the end connecting plates, the continuity of load transmission can be maintained. [Brief explanation of the drawings]

[0030] [Figure 1] (a) is a vertical cross-sectional view showing a schematic diagram of the joint-type steel-concrete composite deck that is the subject of the present invention, and (b) is a plan view showing a schematic diagram of the joint-type steel-concrete composite deck that is the subject of the present invention. [Figure 2] This is a plan view showing a joint-type steel-concrete composite deck slab connected with horizontal joints. [Figure 3] (a) is a vertical cross-sectional view showing the "end connecting plate" of the joint-type steel-concrete composite deck, and (b) is a front view showing the "slit" formed in the joint-type steel-concrete composite deck. [Figure 4] (a) is a vertical cross-sectional view showing the "lower connecting member" and "upper connecting member" that connect the opposing end connecting plates, and (b) is a front view showing the lower connecting member and upper connecting member that connect the opposing end connecting plates. [Figure 5] (a) is a plan view showing a schematic of a part of a joint-type steel-concrete composite deck with a box-out section formed, and (b) is a plan view showing a left joint-type steel-concrete composite deck and a right joint-type steel-concrete composite deck installed adjacent to each other. [Figure 6] 1A is a front view showing a schematic view of the slit as viewed in the first axial direction, and FIG. 1B is a front view showing a schematic view of the lower connecting member and the upper connecting member inserted into the slit. [Figure 7] (a) A front view showing a schematic of the "rebar accommodation hole" formed in the end connecting plate, and (b) a cross-sectional view showing a schematic of the concrete deck with a primary rebar. [Figure 8] 1A is a cross-sectional view showing a "gap spacer" disposed in a joint portion, and FIG. 1B is a plan view showing a gap spacer disposed in a joint portion. [Figure 9] (a) is a front view showing a schematic diagram of a "lower gap spacer" and an "upper gap spacer", (b) is a front view showing a schematic diagram of a lower gap spacer placed on a lower connecting material and an upper gap spacer placed on an upper connecting material, and (c) is a plan view showing a schematic diagram of an upper gap spacer placed on an upper connecting material. [Figure 10](a) is a front view showing a schematic of a "middle gap spacer" in which lower and upper notches of different diameters are formed, (b) is a front view showing a middle gap spacer installed between a lower connecting member and an upper connecting member, (c) is a front view showing a middle gap spacer in which lower and upper notches of the same diameter are formed, and (d) is a front view showing a middle gap spacer in which one lower notch and one upper notch are formed on the top and bottom. [Figure 11] (a) is a front view showing a schematic representation of a "wedge-shaped gap spacer," (b) is a cross-sectional view showing a schematic representation of a wedge-shaped gap spacer installed between opposing end connecting plates, and (c) is a plan view showing a schematic representation of a wedge-shaped gap spacer installed between opposing end connecting plates. [Figure 12] FIG. 1 is a flow chart showing the flow of the main steps of the deck slab connecting method of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] An example of an embodiment of the joint structure and deck slab connecting method of the present invention will be described with reference to the drawings.

[0032] 1. Joint structure First, the joint structure of the present invention will be described. The deck slab connection method of the present invention is a method for connecting steel-concrete composite deck slabs using the joint structure of the present invention. Therefore, the joint structure of the present invention will be described first, and then the deck slab connection method of the present invention will be described.

[0033] Figure 1 is a diagram showing a precast steel-concrete composite deck (hereinafter referred to as "joint-type steel-concrete composite deck 100") that is the subject of the present invention, where (a) is a vertical cross-sectional view and (b) is a plan view seen from above. As shown in this figure, the joint-type steel-concrete composite deck 100, like conventional precast steel-concrete composite decks, is composed of a bottom steel plate 110 (also called a steel plate panel) and a concrete deck 120, and can also be composed of perforated vertical ribs 130.

[0034] The joint structure of the present invention connects adjacent joint-type steel-concrete composite deck slabs 100, and can connect adjacent joint-type steel-concrete composite deck slabs 100 with "vertical joints" (i.e., adjacent in the direction perpendicular to the bridge axis), or it can connect adjacent joint-type steel-concrete composite deck slabs 100 with "horizontal joints" (i.e., adjacent in the direction of the bridge axis), or it can connect adjacent joint-type steel-concrete composite deck slabs 100 with vertical and horizontal joints (i.e., adjacent on all four sides).For convenience, the direction in which joint-type steel-concrete composite deck slabs 100 are connected will be referred to as the "first axis direction," and the horizontal direction perpendicular or diagonal to that (at least 45° and less than 90°) will be referred to as the "second axis direction."

[0035] For example, Figure 1 shows a case where adjacent joint-type steel-concrete composite deck slabs 100 are connected with vertical joints, in which case the direction perpendicular to the bridge axis is the first axis direction, and the bridge axis direction is the second axis direction. On the other hand, Figure 2 shows a case where adjacent joint-type steel-concrete composite deck slabs 100 are connected with horizontal joints, in which case the bridge axis direction is the first axis direction, and the direction perpendicular to the bridge axis is the second axis direction.

[0036] 3A and 3B are diagrams showing a schematic diagram of an "end connecting plate 140" of the joint-type steel-concrete composite deck 100, where (a) is a cross-sectional view of the end connecting plate 140 cut along a vertical plane in the first axis direction, and (b) is a front view of the end connecting plate 140 as viewed in the first axis direction. As shown in FIG. 4A, the end connecting plate 140 is fixed to the bottom steel plate 110 near the end in the first axis direction. This end connecting plate 140 is positioned so that it is approximately perpendicular (including perpendicular) to the bottom steel plate 110 and so that its long axis direction is the second axis direction, and is then fixed to the bottom steel plate 110 by, for example, welding. In this figure, the bottom steel plate 110 is fixed to both ends in the first axial direction, but when connecting to the joint-type steel-concrete composite deck 100 on only one side (for example, the right side), the bottom steel plate 110 is fixed to only that one side, and when connecting to the joint-type steel-concrete composite deck 100 in all four directions, the bottom steel plate 110 is fixed to all four sides (i.e., surrounding the periphery). Hereinafter, of the end faces (side faces) formed on the joint-type steel-concrete composite deck 100, the end face to which the bottom steel plate 110 is fixed will be referred to specifically as the "connection end face."

[0037] 3(b), multiple (six in the figure) slits 150 are formed at intervals in the second axial direction in the end connecting plate 140. These slits 150 are cutout holes that open at the top of the end connecting plate 140 and extend downward in a strip shape when the bottom steel plate 110 is positioned so that it is approximately horizontal (including horizontal).

[0038] FIG. 4 is a diagram showing a "lower connecting member 161" and an "upper connecting member 162" that connect opposing end connecting plates 140, where (a) is a cross-sectional view cut along a vertical plane in the first axial direction, and (b) is a front view of the end connecting plate 140 as viewed in the first axial direction. When two joint-type steel-concrete composite deck slabs 100 are installed adjacent to each other, the end connecting plates 140 are positioned so that they face each other, and a gap (hereinafter referred to as the "joint JT") is formed between these end connecting plates 140. For convenience, one adjacent joint-type steel-concrete composite deck slab 100 (the left side in the figure) will be referred to as the "left joint-type steel-concrete composite deck slab 100L," and the other adjacent joint-type steel-concrete composite deck slab 100 (the right side in the figure) will be referred to as the "right joint-type steel-concrete composite deck slab 100R."

[0039] As shown in Figure 4(b), the lower connecting member 161 and the upper connecting member 162 are arranged in two rows, one above the other, within the slit 150. At this time, it is preferable to insert the lower connecting member 161 so as to drop it through the opening of the slit 150, and then insert the upper connecting member 162 so as to drop it through the opening as well. In this figure, a spacer SP is arranged between the lower connecting member 161 and the upper connecting member 162 to provide a predetermined gap.

[0040] The lower connector 161 and the upper connector 162 are inserted through the slits 150 of the left-joint steel-concrete composite deck 100L and the right-joint steel-concrete composite deck 100R, so as to span the opposing end connecting plates 140. The lower connector 161 and the upper connector 162, inserted through both slits 150, are then fastened together with nuts or other fasteners. Axial force can also be applied by using high-strength bolts as the lower connector 161 and the upper connector 162 and controlling the torque during tightening. While mortar or other materials are typically used to fill the joints JT, as described below, it is also possible to fill the joints JT with mortar while the lower connector 161 and the upper connector 162 are in place and then apply axial force to the high-strength bolts after the mortar has hardened. This is advantageous because it prevents cracking of the mortar and further improves joint strength. As the lower connecting member 161 and the upper connecting member 162, various bolts including ordinary bolts as well as high strength bolts can be used, and other bolts such as PC steel rods and reinforcing bars can also be used.

[0041] When fastening the lower connecting member 161 and the upper connecting member 162 with nuts or the like, a "box cutout portion UB" shown in Fig. 5 is used. Fig. 5 is a diagram showing the box cutout portion UB formed in the joint-type steel-concrete composite deck 100, where (a) is a plan view of a portion of the joint-type steel-concrete composite deck 100 viewed from above, and (b) is a plan view of a portion of the adjacently installed left-joint-type steel-concrete composite deck 100L and right-joint-type steel-concrete composite deck 100R viewed from above.

[0042] As shown in Figure 5(a), a box cutout portion UB is formed near the connection end face of the joint-type steel-concrete composite deck 100. However, the box cutout portion UB is formed to include the slit 150 of the end connecting plate 140, and therefore the box cutout portion UB is arranged with a gap in the second axial direction, just like the slit 150. By forming the box cutout portion UB in this way, a space is formed around the lower connecting member 161 and the upper connecting member 162 inserted into the slit 150, as shown in Figure 5(b), and this space can be used to perform tightening work using nuts or the like.

[0043] In the example of Figure 4, a spacer SP needs to be placed between the lower connecting member 161 and the upper connecting member 162, but as shown in Figure 6, the spacer SP shown in Figure 4 can be omitted by making the cross-sectional diameter (for example, diameter) of the upper connecting member 162 larger than the cross-sectional diameter of the lower connecting member 161. Figure 6 is a diagram schematically showing a slit 150 in which an "upper accommodating hole 150C" and a "lower accommodating groove 150G" are formed, where (a) is a front view of the slit 150 as seen in the first axial direction, and (b) is a front view of the lower connecting member 161 and the upper connecting member 162 inserted into the slit 150 as seen in the first axial direction.

[0044] 6 has an open upper storage hole 150C formed at its top, and a lower storage groove 150G extending downward from this upper storage hole 150C in a strip-like shape, with these upper storage hole 150C and lower storage groove 150G communicating with each other. Upper connecting member 162 inserted into this slit 150 has a larger diameter than lower connecting member 161, and lower storage groove 150G has a narrower width than the cross-sectional diameter of upper connecting member 162. However, lower storage groove 150G is formed with a width sufficient to allow lower connecting member 161 to pass through, while upper storage hole 150C is formed with a size sufficient to accommodate part (or all) of upper connecting member 162. As a result, as shown in Figure 6(b), the lower connecting material 161 inserted by dropping it from above the slit passes through the upper storage hole 150C and is placed on the bottom of the lower connecting material 161, and similarly, the upper connecting material 162 inserted by dropping it from above is placed on the upper storage hole 150C without entering the lower storage groove 150G.

[0045] Reinforcing bars such as main reinforcement bars and distribution bars are installed in the concrete slab 120 of the joint-type steel-concrete composite slab 100. Of these reinforcing bars, those arranged in the first axis direction (hereinafter, particularly referred to as "first axis reinforcing bars RB") can also be placed on the end connecting plate 140 as shown in Fig. 7. Fig. 7 is a diagram schematically showing the "reinforcing bar accommodation holes 151" formed in the end connecting plate 140, where (a) is a front view of the end connecting plate 140 as seen in the first axis direction, and (b) is a cross-sectional view of the concrete slab 120 cut by a vertical plane in the first axis direction.

[0046] 7(a), a plurality of (four in the figure) reinforcing bar accommodating holes 151 can be formed at intervals in the second axial direction in the end connecting plate 140. These reinforcing bar accommodating holes 151 open at the top of the end connecting plate 140 when the bottom steel plate 110 is arranged so as to be approximately horizontal (including horizontal), and are formed to be large enough to accommodate part (or all) of the first axial reinforcing bar RB.

[0047] As shown in FIG. 7(b), the first reinforcing bar RB placed in the reinforcing bar receiving hole 151 is supported by the end connecting plate 140, with its tip end protruding outward from the end connecting plate 140 (to the right end in the figure). The protruding portion of the first reinforcing bar RB is provided with a screw, allowing it to be tightened with a nut or the like. This structure allows the first reinforcing bar RB to be fixed to the end connecting plate 140, thereby maintaining continuity of load transmission. Furthermore, by controlling the torque when tightening with a nut or the like, the axial force of the first reinforcing bar RB can be actively applied to the concrete slab 120, i.e., prestress can be introduced into the concrete slab 120. Furthermore, by welding a stud to the end connecting plate 140 on the concrete slab 120 side of the end connecting plate 140 and lapping it with the first reinforcing bar RB, the concrete slab 120 and the end connecting plate 140 can be integrated. Of course, the process of fastening the primary reinforcing bars RB with nuts or the like and the process of welding studs to the end connecting plates 140 are carried out when the joint-type steel-concrete composite deck 100 is manufactured, that is, in the factory.

[0048] As explained above, the lower connecting member 161 and the upper connecting member 162 inserted through the slit 150 are fastened with nuts or the like. In this case, it is desirable to place a spacer (hereinafter, specifically referred to as a "gap spacer 170") between the opposing end connecting plates 140 (i.e., the joint portion JT) as shown in FIG. 8. FIG. 8 is a diagram schematically showing the "gap spacer 170" placed in the joint portion JT, where (a) is a cross-sectional view cut along a vertical plane in the first axial direction, and (b) is a plan view viewed from above. The gap spacer 170 shown in this figure is placed so as to fill the gap between the opposing end connecting plates 140 as shown in FIG. 8(a), and is also placed at a position that avoids the lower connecting member 161 and the upper connecting member 162 as shown in FIG. 8(b).

[0049] The gap spacer 170 is not limited to the example shown in Fig. 8, and various configurations can be used. For example, the gap spacer 170 shown in Fig. 9 is configured to include a "lower gap spacer 171" and an "upper gap spacer 172." Fig. 9 is a diagram schematically showing the lower gap spacer 171 and the upper gap spacer 172, where (a) is a front view seen in the first axial direction, (b) is a front view of the lower gap spacer 171 placed on the lower connecting member 161 and the upper gap spacer 172 placed on the upper connecting member 162 seen in the first axial direction, and (c) is a plan view of the upper gap spacer 172 placed on the upper connecting member 162 seen from above.

[0050] As shown in Figure 9(a), a plurality of (two in the figure) lower cutout portions 171H capable of accommodating the upper portions of the lower connecting members 161 are formed on the lower surface of the lower gap spacer 171, and similarly, a plurality of (two in the figure) upper cutout portions 172H capable of accommodating the upper portions of the upper connecting members 162 are formed on the lower surface of the upper gap spacer 172. Then, as shown in Figures 9(b) and 9(c), the lower gap spacer 171 is placed on the upper surface of the lower connecting member 161, and the upper gap spacer 172 is placed on the upper surface of the upper connecting member 162. At this time, the lower gap spacer 171 and the upper gap spacer 172 are placed so that the upper portions of two or more lower connecting members 161 lined up in the second axial direction are accommodated in the lower cutout portions 171H, and the upper portions of two or more upper connecting members 162 lined up in the second axial direction are accommodated in the upper cutout portions 172H. In this way, by placing the lower gap spacer 171 or the upper gap spacer 172 so as to straddle two or more lower connecting members 161 or upper connecting members 162, it is possible to prevent the lower gap spacer 171 or the upper gap spacer 172 from rotating and falling. When using the gap spacer 170 shown in Fig. 9, it is advisable to insert the lower gap spacer 171 into the slit 150 before placing the lower connecting member 161, and then insert the upper connecting member 162 into the slit 150 before placing the upper gap spacer 172.

[0051] 10A and 10B are front views of the middle gap spacer 173, in which (a) is a front view of the middle gap spacer 173 in which a lower cutout 171H and an upper cutout 172H of different diameters are formed, viewed in the first axial direction; (b) is a front view of the middle gap spacer 173 installed between the lower connecting member 161 and the upper connecting member 162 in which a lower cutout 171H and an upper cutout 172H of the same diameters are formed; and (d) is a front view of the middle gap spacer 173 in which one lower cutout 171H and one upper cutout 172H are formed on the top and bottom.

[0052] As shown in FIG. 10(a), the lower surface of the middle gap spacer 173 is formed with a plurality of (two in the figure) lower cutout portions 171H capable of accommodating the upper portions of the lower connecting members 161, and the upper surface thereof is formed with a plurality of (two in the figure) upper cutout portions 172H capable of accommodating the lower portions of the upper connecting members 162. Then, as shown in FIG. 10(b), the middle gap spacer 173 is installed between the lower connecting members 161 and the upper connecting members 162. At this time, the middle gap spacer 173 is installed so that the upper portions of two or more lower connecting members 161 lined up in the second axial direction are accommodated in the lower cutout portions 171H, and the lower portions of two or more upper connecting members 162 lined up in the second axial direction are accommodated in the upper cutout portions 172H. When the middle gap spacer 173 is used, it is preferable to insert the lower gap spacer 171 into the slit 150, place the middle gap spacer 173, and then insert the upper connecting member 162 into the slit 150.

[0053] The lower cutout portion 171H and the upper cutout portion 172H formed in the middle gap spacer 173 can have different diameters as shown in Figure 10(a) (in this figure, the upper cutout portion 172H has a larger diameter), or they can have the same diameter as shown in Figure 10(c). Also, as shown in Figure 10(d), the middle gap spacer 173 can have one lower connecting member 161 formed on its lower surface and one upper cutout portion 172H formed on its upper surface. In this case, naturally, the upper part of one lower connecting member 161 is accommodated in the lower cutout portion 171H of the middle gap spacer 173, and similarly, the lower part of one upper connecting member 162 is accommodated in the upper cutout portion 172H.

[0054] The gap spacer 170 shown in Fig. 11 (hereinafter referred to particularly as the "wedge-shaped gap spacer 174") is wedge-shaped with an inclined surface (hereinafter referred to as the "inclined surface 174S") formed on part of it. Fig. 11 is a diagram showing a schematic diagram of the "wedge-shaped gap spacer 174", where (a) is a front view seen in the first axial direction, (b) is a cross-sectional view of the wedge-shaped gap spacer 174 installed between opposing end connecting plates 140 cut by a vertical plane in the first axial direction, and (c) is a plan view of the wedge-shaped gap spacer 174 installed between opposing end connecting plates 140 seen from above.

[0055] As shown in Figure 11(a), the wedge-shaped gap spacer 174 has an inclined surface 174S formed thereon, and two wedge-shaped gap spacers 174 are used as a set. Specifically, as shown in Figure 11(a), the lower wedge-shaped gap spacer 174 is arranged so that its inclined surface 174S tapers upward, while the upper wedge-shaped gap spacer 174 is arranged so that its inclined surface 174S tapers downward. In this case, after installing the lower wedge-shaped gap spacer 174, it is advisable to install the upper wedge-shaped gap spacer 174 by pushing it downward so that the inclined surfaces 174S of both spacers abut.

[0056] As shown in Figure 11(c) , the wedge-shaped gap spacer 174 is installed in a position that avoids the lower connecting member 161 and the upper connecting member 162. Therefore, the operation of inserting the lower gap spacer 171 and the upper connecting member 162 into the slit 150 and the operation of installing the wedge-shaped gap spacer 174 do not interfere with each other, and each operation can be performed in a desired order. Alternatively, the wedge-shaped gap spacer 174 can be installed so as to overlap the positions of the lower gap spacer 171 and the upper connecting member 162 without avoiding the lower gap spacer 171 and the upper connecting member 162. In this case, it is preferable to form a slit in the wedge-shaped gap spacer 174 and accommodate the lower gap spacer 171 and the upper connecting member 162 in the slit portion.

[0057] 2. Floor slab connection method Next, the deck slab connecting method of the present invention will be explained with reference to Figure 12. The deck slab connecting method of the present invention is a method for connecting joint-type steel-concrete composite deck slabs 100 using the joint structure of the present invention explained so far. Therefore, we will avoid explanations that overlap with the content explained in the joint structure of the present invention, and will mainly explain content that is unique to the deck slab connecting method of the present invention. In other words, content not mentioned here is the same as that explained in "1. Joint structure."

[0058] Figure 12 is a flow chart showing the main steps of the deck slab connecting method of the present invention. When connecting joint-type steel-concrete composite decks 100 using the joint structure of the present invention, first, as shown in this figure, the left-side joint-type steel-concrete composite deck 100L and the right-side joint-type steel-concrete composite deck 100R are installed (Step 201 in Figure 12). At this time, the connecting end faces of the left-side joint-type steel-concrete composite deck 100L and the right-side joint-type steel-concrete composite deck 100R are installed so that they face each other, i.e., so that the end connecting plates 140 of both decks face each other.

[0059] After the adjacent joint-type steel-concrete composite deck slabs 100 are installed, a lower connector 161 is inserted through the slit 150 of the end connecting plate 140 of the left-joint type steel-concrete composite deck slab 100L, and the lower connector 161 is also inserted through the slit 150 of the end connecting plate 140 of the right-joint type steel-concrete composite deck slab 100R (Step 202 in FIG. 12). Next, an upper connector 162 is inserted through the slit 150 of the end connecting plate 140 of the left-joint type steel-concrete composite deck slab 100L, and the upper connector 162 is also inserted through the slit 150 of the end connecting plate 140 of the right-joint type steel-concrete composite deck slab 100R (Step 203 in FIG. 12). After the lower connector 161 and the upper connector 162 are inserted through both slits 150, a gap spacer 170 is placed between the opposing end connecting plates 140 (Step 204). As already mentioned, the order of the installation of the lower connecting member 161 (Step 202), the installation of the upper connecting member 162 (Step 203 in FIG. 12), and the installation of the gap spacer 170 (Step 204) may be changed as appropriate depending on the configuration of the gap spacer 170 used. Also, depending on the situation, such as when the space between the opposing end connecting plates 140 is relatively narrow, the installation of the gap spacer 170 (Step 204) may be omitted.

[0060] Once the gap spacer 170 is placed between the opposing end connecting plates 140, the box cutout portion UB is used to fasten the lower connecting member 161 and the upper connecting member 162 with nuts or the like (Step 205 in Figure 12). If high-strength bolts are used for the lower connecting member 161 and the upper connecting member 162, axial force can be applied by torque management during tightening. As with the installation of the gap spacer 170 (Step 204), the process of fastening the lower connecting member 161 and the upper connecting member 162 (Step 205 in Figure 12) can be omitted depending on the situation. Once the lower connecting member 161 and the upper connecting member 162 are fastened, mortar or concrete is filled into the joint portion JT (Step 206 in Figure 12), and finally, mortar or concrete is filled into the box cutout portion UB (Step 207 in Figure 12). In addition, when high-strength bolts are used as the lower connecting member 161 and the upper connecting member 162, mortar can be filled into the joint JT (Step 206) while the lower connecting member 161 and the upper connecting member 162 are in place (Step 202 to Step 203), and axial force can be introduced into the high-strength bolts after the mortar has hardened (Step 205 in Figure 12). [Industrial Applicability]

[0061] The joint structure and deck connection method of the present invention can be used for bridges of all types, such as road bridges and railway bridges, as well as for bridges that cross various types of structures, such as river bridges, overpasses, and railway bridges. Furthermore, the present invention can be applied not only to deck replacement work for existing bridges, but also to new bridge construction work. Considering that the present invention can provide safer transportation and ultimately extend the lifespan of bridges, it can be said to be an invention that can be expected to not only be used industrially but also make a significant contribution to society. [Explanation of symbols]

[0062] 100 Jointed steel-concrete composite deck 100L Left-hand joint steel-concrete composite deck 100R Right-hand joint steel-concrete composite deck 110 Bottom steel plate (for jointed steel-concrete composite deck) 120 (Jointed steel-concrete composite deck) Deck concrete 130 Perforated longitudinal ribs (for jointed steel-concrete composite decks) 140 (Jointed steel-concrete composite deck) End connecting plate 150 (End connecting plate) slit 150C (Slit) Upper Receiving Hole 150G (Slit) Lower Receiving Groove 151 (Slit) Reinforcement bar accommodation hole 161 Lower connecting material 162 Upper connecting material 170 Gap spacer 171 (of gap spacers) Lower gap spacer 171H (Lower clearance spacer) lower notch 172 (of gap spacers) upper gap spacer 172H (Upper gap spacer) Upper notch 173 Middle gap spacer (among gap spacers) 174 (Among gap spacers) Wedge-type gap spacer 174S (Wedge-type gap spacer) Inclined surface JT joint area RB 1st axis rebar SP Spacer UB box removal section

Claims

1. A joint structure that connects a precast steel concrete composite deck made of a bottom steel plate and a deck concrete in a first axial direction, An end connecting plate is fixed to an end of the bottom steel plate in the first axis direction, the end connecting plate being arranged in a second axis direction that is perpendicular or approximately perpendicular to the bottom steel plate and perpendicular or oblique to the first axis direction, The end connecting plate is formed with a plurality of slits aligned in the second axial direction, The slit is a band-shaped hole that is open at the top of the end connecting plate when the bottom steel plate is placed horizontally or approximately horizontally, A plurality of rod-shaped lower connecting members inserted into the slits; a plurality of rod-shaped upper connecting members disposed above the lower connecting members and inserted into the slits; The lower connecting member and the upper connecting member are inserted into the slits of the end connecting plates of the adjacent steel concrete composite slabs, and then the lower connecting member and the upper connecting member are tightened to connect the adjacent steel concrete composite slabs. A joint structure characterized by the above.

2. The cross-sectional diameter of the upper connecting member is larger than the cross-sectional diameter of the lower connecting member, The slit includes an upper accommodating hole formed in the opening and configured to accommodate the upper connecting member, and a lower accommodating groove communicating with the upper accommodating hole, The lower accommodation groove has a width narrower than a cross-sectional diameter of the upper connecting member, The lower connecting member inserted from above the slit is placed on the bottom of the lower accommodation groove, The upper connecting member inserted from above the slit is placed in the upper accommodating hole.

2. The joint structure according to claim 1, wherein:

3. Further provided is a gap spacer having a thickness equivalent to the width of the joint formed when the end connecting plates of the adjacent steel concrete composite floor slabs face each other, The adjacent steel concrete composite deck slabs are connected by placing the gap spacer in the joint portion and then tightening the lower connecting material and the upper connecting material.

2. The joint structure according to claim 1, wherein:

4. The gap spacers include a lower gap spacer disposed above the lower connecting member and an upper gap spacer disposed above the upper connecting member, Two or more lower cutouts are formed on the lower surface of the lower gap spacer to accommodate upper portions of the lower connecting members, Two or more upper notches are formed on the lower surface of the upper gap spacer to accommodate the upper portions of the upper connecting members, The lower gap spacer is arranged so that the lower cutout portion accommodates upper portions of two or more of the lower connecting members arranged in the second axial direction, The upper gap spacer is arranged so that the upper notch portion accommodates upper portions of two or more upper connecting members arranged in the second axial direction.

4. The joint structure according to claim 3, wherein:

5. The gap spacer has one or more lower notches formed on its lower surface to accommodate the upper portions of the lower connecting members, and one or more upper notches formed on its upper surface to accommodate the lower portions of the upper connecting members, The gap spacer is arranged so that the lower cutout portion accommodates the upper portion of the lower connecting member and the upper cutout portion accommodates the lower portion of the upper connecting member.

4. The joint structure according to claim 3, wherein:

6. the gap spacer is wedge-shaped with an inclined surface, The gap spacers are arranged in a lower row and an upper row in the joint portion, the lower gap spacer is arranged such that the inclined surface tapers upward; the upper gap spacer is arranged so that the inclined surface tapers downward and the inclined surface of the lower stage abuts against the inclined surface of the upper stage; 4. The joint structure according to claim 3, wherein:

7. A plurality of reinforcing bar accommodating holes aligned in the second axial direction are formed in the end connecting plate, The reinforcing bar accommodation hole is formed so that an upper portion of the end connecting plate is open when the bottom steel plate is placed horizontally or approximately horizontally, The first axis reinforcing bar arranged in the first axis direction in the slab concrete protrudes from the end connecting plate in the first axis direction, and a portion of the first axis reinforcing bar is placed in the reinforcing bar receiving hole, The first axial reinforcing bar was tightened using the screw portion provided on the first axial reinforcing bar protruding from the end connecting plate.

2. The joint structure according to claim 1, wherein:

8. A method for connecting a precast steel-concrete composite deck made of a bottom steel plate and a deck concrete in a first axial direction, An end connecting plate is fixed to an end of the bottom steel plate in the first axis direction, the end connecting plate being arranged in a second axis direction that is perpendicular or approximately perpendicular to the bottom steel plate and perpendicular or oblique to the first axis direction, The end connecting plate is formed with a plurality of slits aligned in the second axial direction, The slit is a band-shaped hole that is open at the top of the end connecting plate when the bottom steel plate is placed horizontally or approximately horizontally, a steel-concrete composite deck installation step of installing one of the steel-concrete composite decks adjacent to the other of the steel-concrete composite decks; a lower connecting member installation process in which a rod-shaped lower connecting member is inserted into the slit relating to the end connecting plate of one of the steel concrete composite decks, while the lower connecting member is inserted into the slit relating to the end connecting plate of the other steel concrete composite deck; an upper connecting member installation process in which a rod-shaped upper connecting member is inserted into the slit relating to the end connecting plate of one of the steel concrete composite decks, while the upper connecting member is inserted into the slit relating to the end connecting plate of the other steel concrete composite deck; and a connecting member tightening step of tightening the lower connecting member inserted through the slit and tightening the upper connecting member inserted through the slit. A deck slab connecting method characterized by the above.

9. The method further includes a gap spacer placement step of placing a gap spacer having a thickness equivalent to the width of the joint portion formed by the end connecting plates of the adjacent steel concrete composite floor slabs facing each other, in the joint portion, In the connecting material tightening step, the gap spacer is placed in the joint portion, and then the lower connecting material inserted into the slit is tightened, and the upper connecting material inserted into the slit is tightened.

9. The deck slab connecting method according to claim 8.

10. Further provided is a joint filling process of pouring mortar or concrete into the joints formed by the end connecting plates of the adjacent steel concrete composite floor slabs facing each other, The joint filling process is performed after the connecting material tightening process.

9. The deck slab connecting method according to claim 8.

11. A joint filling process of pouring mortar or concrete into joints formed by the end connecting plates of adjacent steel concrete composite floor slabs facing each other; and a box-out portion filling step of pouring mortar into the box-out portion where the deck concrete is boxed out so as to include the slit of the end connecting plate. In the connecting material tightening process, after the mortar or concrete poured in the joint filling process has hardened, the lower connecting material and the upper connecting material are tightened using the box punching portion.

9. The deck slab connecting method according to claim 8.

Images