Joint structure between existing girder and replacement girder

Abstract

To provide a joint structure between an existing girder and a renewed girder, which is excellent in travelability and earthquake resistance at a joint between the existing girder and the renewed girder, and which is excellent in maintenance such as the maintenance of the joint.SOLUTION: An end of an existing girder 2 and an end of a replacement girder 3 are joined to each other at an upper end of a pier 1 positioned at a boundary between an existing section A where the existing girder 2 is erected and a replacement section B where the replacement girder 3 is erected. A plurality of cross beams 5 are arranged at the upper end of a bridge pier 1 so as to be separated from each other in the direction perpendicular to the bridge axis. An upper girder 16 is arranged at the upper end of the cross girder 5 in the direction perpendicular to the bridge axis across the cross girders 5, 5. A joint plate 8 is arranged between the end of the existing girder 2 and the end of the renewed girder 3. The joint plate 8 is detachably fixed to the upper end of the upper girder 16. The end side 8a on the existing girder 2 side of the joint plate 8 is slidably extended by a predetermined length in the bridge-axis direction along the upper surface of the existing girder 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the joint structure between the existing girder and the replacement girder in a continuous viaduct consisting of a plurality of piers arranged at intervals and a plurality of simple or continuous girders erected in succession between the plurality of piers, and is designed to provide excellent running performance and earthquake resistance at the joint between the existing girders and the replacement girders, as well as excellent maintenance and management such as maintenance of the joint, and to enable efficient replacement work of the existing girders during replacement. [Background technology]

[0002] When replacing a viaduct consisting of continuous girders erected in succession between multiple piers spaced apart, or multiple simple girders erected between each pier, it is often not possible to renew the entire viaduct section or a specified section in a single replacement work due to constraints such as construction time and cost, and so the section to be replaced is usually divided into multiple sections in the bridge axis direction and the work is carried out in sequence.

[0003] Furthermore, in such cases, only a portion of the section to be replaced is rebuilt, and work is not started on the remaining sections. As a result, the existing section and the renovated section that has already been replaced are often left as they are.

[0004] However, if the structures of the existing and renewed sections of a continuous viaduct are significantly different, the joints between the existing and renewed sections are not structurally continuous, which poses the problem of poorer drivability and seismic resistance than before the renewal.

[0005] Furthermore, it is often difficult to set the same design vibration unit for the existing section and the renewal section due to discontinuities in the structure, etc. Furthermore, when existing continuous girders are cut and connected to renewal girders, the joints between the existing and renewal girders are often generally narrow in space, which makes maintenance of the joints difficult.

[0006] Known methods for solving these issues include structures that connect individual deck slabs or structures that connect bridges with different numbers of main girders, but there are no methods for joining existing and updated girders using different materials.

[0007] For example, Patent Document 1 discloses an invention for a continuous simple girder bridge structure in which adjacent simple girder bridges in the bridge axis direction are firmly connected at the upper ends of the piers to form a continuous girder bridge, thereby eliminating the need for expansion joints, allowing for smooth, continuous movement of vehicles and suppressing deterioration due to vibration.

[0008] Simply put, adjacent simple girder bridges are connected at the upper ends of the piers by connecting concrete members that run continuously across both simple girder bridges and are cast in the main girder installation area on the underside of the deck.

[0009] Furthermore, Patent Document 2 discloses an invention relating to a continuous bridge structure that connects simple girder bridges erected on adjacent spans.

[0010] Simply put, reinforced concrete cross beams are constructed across the width of the bridge between main girders that are installed non-linearly between adjacent spans. Studs (stress transmission members) are melt-inserted into the webs at the ends of each main girder and embedded in the concrete of the cross beams. This connects each main girder and cross beam in a way that allows stress to be transmitted, thereby enabling stress transmission between the main girders that are installed non-linearly between adjacent spans, achieving a continuous bridge. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Publication No. 10-96207 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-137686 [Patent Document 3] Patent No. 3908642 Summary of the Invention [Problem to be solved by the invention]

[0012] However, making the deck slabs continuous and rigidly connecting the ends of the main girders to make them continuous requires work to allow the concrete to develop its strength and tension the PC steel, and is generally difficult to accomplish in a short period of time, such as a week.

[0013] Another issue was that when the girder replacement was resumed, the removal of the connection would be a major undertaking.Furthermore, there were no structures in which the existing girders and the replacement girders were joined using dissimilar materials.

[0014] The present invention has been made to solve the above problems, and aims to provide a joint structure between the existing girder and the replacement girder that is excellent in terms of runnability and earthquake resistance at the joint between the existing girder and the replacement girder, as well as in terms of maintenance and management of the joint, and that allows the existing girder to be efficiently replaced during replacement. [Means for solving the problem]

[0015] The present invention is an invention of a joint structure between an existing girder and a replacement girder, which are joined at the upper end of a pier located at the boundary between an existing section where an existing girder is erected and a replacement section where a replacement girder is erected, and is characterized by comprising a plurality of cross girders arranged at intervals perpendicular to the bridge axis at the upper end of the pier, on which the end of the replacement girder is placed, an upper girder arranged at the upper end of the cross girders in a direction perpendicular to the bridge axis, spanning between the plurality of cross girders, and a joint plate arranged between the end of the existing girder and the end of the replacement girder, fixed to the upper end of the upper girder, and with the existing girder side extended in the direction of the bridge axis along the upper surface of the existing girder.

[0016] In particular, by placing an upper girder at the upper end of the cross girder, the roadbed surface on the top surface of the existing girder and the roadbed surface on the top surface of the renewed girder can be adjusted to the same height, and by placing a joint board between the end of the existing girder and the end of the renewed girder, it is possible to maintain the ease of travel between the existing girder and the renewed girder.

[0017] In addition, by installing the existing girder side of the joint plate on the top surface of the existing girder so that it can slide in the bridge axis direction, it is possible to absorb displacement between the existing girder and the renewed girder during an earthquake, etc.

[0018] Furthermore, by interposing a buffer member between the existing girder and the cross girder, it is possible to improve earthquake resistance by mitigating the impact when the existing girder and the cross girder collide during an earthquake, etc. Also, by interposing a water-stopping member between the upper girder and the existing girder, it is possible to prevent damage due to water leakage at the joint.

[0019] In addition, by placing multiple cross girders at intervals perpendicular to the bridge axis at the upper end of the pier and placing an upper girder on top of the multiple cross girders, spanning between the cross girders, and creating a maintenance and management space at the upper end of the pier to maintain and manage the joint between the existing girder and the renewed girder, maintenance such as inspection of the renewed girder end can be carried out smoothly. [Effects of the Invention]

[0020] The present invention is an invention of the joint structure between the existing girder and the updated girder at the upper end of a bridge pier located at the boundary between the existing section where the existing girder is erected and the updated section where the updated girder is erected.In particular, the present invention is equipped with a joint plate that is placed between the end of the existing girder and the end of the updated girder, fixed to the upper end of the upper girder, and the existing girder side is extended in the bridge axis direction along the upper surface of the existing girder, resulting in very good travelability at the joint between the existing girder and the updated girder.

[0021] Furthermore, since the joint plate is installed so that it can slide on the top surface of the existing girder in the bridge axis direction, it can absorb displacement between the existing girder and cross girder during an earthquake, etc., and since a buffer member is interposed between the cross girder and the existing girder, it can mitigate impacts when the existing girder and cross girder collide during an earthquake, etc., and can prevent destruction of the joint, resulting in excellent earthquake resistance.

[0022] Furthermore, a maintenance space is provided at the upper end of the pier to maintain and manage the joint between the existing girder and the renewed girder, which consists of the cross girder and upper girder, so maintenance such as repair and inspection of the joint can be carried out smoothly. [Brief explanation of the drawings]

[0023] [Figure 1] This is a vertical cross-sectional view showing the joint between the existing girder and the renewal girder at the upper end of the pier located at the boundary between the existing section where the existing girder is erected and the renewal section where the renewal girder is erected. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line BB in FIG. [Figure 4] This is another embodiment of the present invention, and is a longitudinal cross-sectional view showing the joint between the existing girder and the renewal girder, where the concrete roadbed in the renewal section is made of an RC deck. [Figure 5] 5 is a cross-sectional view taken along line CC in FIG. 4. [Figure 6] FIG. 5 is a cross-sectional view taken along the line DD in FIG. [Figure 7] FIG. 5 is a perspective view of an update interval in FIG. [Figure 8] This is another embodiment of the present invention, where Figure (a) is a plan view of the boundary between the existing section and the renewed section, and Figure (b) is a longitudinal cross-sectional view perpendicular to the bridge axis. [Figure 9] 8(a) and 8(b) are cross-sectional views taken along lines EE and FF in FIG. 8(b), respectively. [Figure 10] This is a vertical cross-sectional view in the bridge axis direction at the boundary between the existing section and the renewed section. [Figure 11] It is a continuous viaduct consisting of multiple piers spaced apart in the bridge axis direction and multiple simple girders erected between each pier. (a) is a partial side view, and (b) is a side view showing the upper end of the pier located at the boundary between the existing section where the existing girders have been erected and the renewal section where the existing girders will be removed and the renewal girders will be erected. [Figure 12] This is an oblique view of the upper end of the pier, showing the construction procedure for the joint between the existing girder and the renewal girder in the existing section and the renewal section. [Figure 13] FIG. 13 is a perspective view of the upper end of the pier, showing the construction procedure following FIG. [Figure 14] FIG. 14 is a perspective view of the upper end of the pier, showing the construction procedure following FIG. [Figure 15] FIG. 15 is a perspective view of the upper end of the pier in FIG. [Figure 16] FIG. 16 is a perspective view of the upper end of the pier, showing the construction procedure following FIG. [Figure 17] FIG. 17 is a perspective view of the upper end of the pier, showing the construction procedure following FIG. [Figure 18] FIG. 18 is a vertical cross-sectional view of the upper end of the pier in FIG. [Figure 19] FIG. 18 is a perspective view of the upper end of the pier, showing the construction procedure following FIG. [Figure 20] FIG. 20 is a perspective view of the upper end of the pier, showing the construction procedure following FIG. 19. [Figure 21] FIG. 21 is a perspective view of the upper end of the pier, showing the construction procedure following FIG. 20. [Figure 22] FIG. 22 is an enlarged perspective view of the upper end of the pier in FIG. 21. [Figure 23] FIG. 23 is an enlarged perspective view of the upper end of the pier in FIG. 22. [Figure 24] FIG. 24 is an enlarged perspective view of the upper end of the pier in FIG. 23. [Figure 25] FIG. 25 is a perspective view of the upper end of the pier, showing the construction procedure following FIG. 24. [Figure 26] FIG. 26 is a perspective view of the upper end of the pier, showing the construction procedure following FIG. 25. [Figure 27] FIG. 27 is a perspective view of the upper end of the pier, showing the construction procedure following FIG. 26. [Figure 28] This is a perspective view of the upper end of the pier showing the construction procedure following Figure 27. [Figure 29] This is a vertical cross-sectional view of the upper end of the pier after the replacement of the existing section and the renewed section has been completed. DETAILED DESCRIPTION OF THE INVENTION

[0024] Figures 1 to 3 show one embodiment of the present invention, illustrating the joints between the existing girders and the replacement girders of a continuous viaduct consisting of multiple piers spaced apart in the bridge axis direction and multiple simple girders erected between each pier.

[0025] In the figure, at the upper end of pier 1, which is located at the boundary between existing section A where existing girder 2 is erected and updated section B where updated girder 3 is erected, the end of existing girder 2 is placed on the upper end of pier 1 via bearing 4, and the end of updated girder 3 is placed on the upper end of pier 1 via bearing 4A and cross girder 5 installed on bearing 4A.

[0026] In addition, the existing roadbed 6 is laid on top of the existing girder 2, and the updated roadbed 7 is laid on top of the updated girder 3, with a joint board 8 placed between the existing roadbed 6 and the updated roadbed 7.Furthermore, asphalt pavement 9 is laid flush with the joint board 8 on top of the existing roadbed 6 and the updated roadbed 7, making it possible to drive continuously on top of the existing roadbed 6 and the updated roadbed 7 in the direction of the bridge axis.

[0027] Existing girder 2 and replacement girder 3 are installed at equal intervals perpendicular to the bridge axis and parallel to the bridge axis. Existing girder 2 is a pretensioned PC girder, and replacement girder 3 is a steel girder.

[0028] In addition, the structural type of the existing girder 2 is not limited to pretensioned PC girders, and it is possible to replace the updated girder 3 with any structural type, such as steel girders or reinforced concrete girders.

[0029] The renewal girder 3 is formed primarily from structural steel materials such as H-shaped steel and prefabricated steel, and has an erection protrusion 10 formed at the end in the bridge axis direction in particular. The erection protrusion 10 is placed on the cross girder 5 and joined to the cross girder 5 by a plurality of joining bolts 11.

[0030] In addition, a bottom steel plate 12 is laid continuously on the top surface of the updated girder 3 over multiple adjacent updated girders 3, 3 in the direction perpendicular to the bridge axis, and multiple horizontal ribs 13 made of structural steel such as I-beams are arranged on the bottom steel plate 12, and multiple vertical reinforcement bars 14 are arranged on the horizontal ribs 13.

[0031] The horizontal ribs 13 are arranged at equal intervals in the bridge axis direction and parallel to the direction perpendicular to the bridge axis. The vertical reinforcement bars 14 are arranged in the bridge axis direction. Then, roadbed concrete 15 is poured on top of the bottom steel plate 12, and the bottom steel plate 12, horizontal ribs 13, reinforcement bars 14, and roadbed concrete 15 are integrated to form the renewed roadbed 7.

[0032] Furthermore, if the renewed girder 3 and renewed roadbed 7 (bottom steel plate 12, horizontal ribs 13, reinforcing bars 14, and roadbed concrete 15) are pre-assembled as a composite deck panel unit (hereinafter referred to as "panel unit X") at a factory or the like to a size that can be transported by heavy machinery, these components can be laid in a single laying operation, making it possible to significantly reduce the labor required for on-site work.

[0033] The cross beams 5 are arranged at intervals along the end face of the existing girder 2 at the upper end of the pier 1 via the bearing 4A, in a direction perpendicular to the bridge axis. Each cross beam 5 is formed to a length that allows the erection of multiple adjacent renewal girders 3 in the direction perpendicular to the bridge axis (a length that allows the erection of the end of one panel unit X).

[0034] An upper girder 16 is placed on top of adjacent cross girders 5, 5 in the direction perpendicular to the bridge axis, spanning the spaces between the cross girders 5, 5. The lower portion of the upper girder 16 between the cross girders 5, 5 is raised to form a roughly arch shape, which provides a maintenance space 19 between adjacent cross girders 5, 5 in the direction perpendicular to the bridge axis for maintenance and inspection of the end of the renewed girder 3, buffer members 17 or water-stopping members 18 (described later), etc. (see Figure 3).

[0035] The cross beams 5 and upper beam 16 are formed primarily from structural steel such as H-shaped steel beams, and the upper beam 16 in particular is a component that forms a maintenance space 19 between adjacent cross beams 5, 5 and adjusts the height of the roadbed 6 on top of the existing girder 2 and the roadbed 7 on top of the updated girder 3 to the same height, and the beam length of the upper beam 16 is determined taking into account the beam lengths of the existing girder 2 and the updated girder 3.

[0036] The buffer members 17 are arranged in at least two locations perpendicular to the bridge axis between the end of the existing girder 2 and the cross girder 5, and the water-stopping members 18 are continuously interposed between the end of the existing girder 2 and the upper girder 16 in the direction perpendicular to the bridge axis.

[0037] In addition, the buffer member 17 is a member that reduces the impact caused by a collision between the existing girder 2 and the cross girder 5 during an earthquake, etc., and is removably attached to the side of the cross girder 5 via a mounting bracket 20 and a mounting bolt.

[0038] The water-stopping member 18 is a member that prevents leakage of rainwater and other water at the joint between the side of the upper girder 16 and the end of the existing girder 2, and is formed continuously from elastic rubber or the like in a direction perpendicular to the bridge axis. The water-stopping member 18 is detachably attached to the side of the upper girder 16 via mounting brackets 21 with multiple mounting bolts.

[0039] The joint plate 8 is formed from a metal plate such as a steel plate, and is installed between the existing roadbed 6 and the renewed roadbed 7 so as to be flush with the asphalt pavement 9 laid on these roadbed surfaces.

[0040] The joint plate 8 is detachably attached to the upper end of the upper girder 16 with a plurality of mounting bolts 22. The end 8a of the joint plate 8 on the existing girder 2 side extends a predetermined length in the bridge axis direction over the upper end surface of the water-stopping member 18 and the upper surface of the end of the existing girder 2, and is installed so that the upper end surface of the water-stopping member 18 and the upper surface of the end of the existing girder 2 can slide in the bridge axis direction.

[0041] In particular, the end 8a of the joint board 8 is extended a predetermined length in the bridge axis direction beyond the upper end surface of the water-stopping member 18 and the upper surface of the end of the existing girder 2, and is attached so that the upper end surface of the water-stopping member 18 and the upper surface of the end of the existing girder 2 can slide in the bridge axis direction. This ensures smooth driving in the bridge axis direction at the joint between the existing roadbed 6 and the renewed roadbed 7, and can easily accommodate expansion and contraction of the joint between the existing girder 2 and the renewed girder 3 during earthquakes, etc.

[0042] With the above configuration, the end of the existing girder 2 and the end of the updated girder 3 are joined at the upper end of the pier 1 located at the boundary between the existing section A and the updated section B.

[0043] 4 to 7 show another embodiment of the present invention, in which the updated roadbed 7 is constructed using an RC deck. A bottom steel plate 12 is laid on the updated girder 3, and an RC deck 27 is laid on the bottom steel plate 12.

[0044] The RC deck 27 is formed to transmit the load to the renewal girder 3 without causing deformation that would impede travel when subjected to the load, and is formed to a size and weight that allows it to be laid using heavy machinery such as a crane.

[0045] It should be noted that the RC deck 27 does not necessarily require the bottom steel plate 12 since it is a structural member in itself.

[0046] Figures 8 to 10 also illustrate another embodiment of the present invention, in which multiple renewal girders 3 are erected in renewal section B, cross girders 5 arranged at both ends of the renewal girders 3 in the bridge axis direction, upper girders 16 arranged on each of the cross girders 5, and joint plates 8 arranged on the upper girders 16 are pre-assembled together to form a unit for each adjacent cross girder 5 in the direction perpendicular to the bridge axis.

[0047] This allows these components to be erected simultaneously in a single operation, significantly reducing on-site labor and shortening the construction period. In the illustrated embodiment, the unitized components are divided into two units for each cross beam 5 in the direction perpendicular to the bridge axis (see Figure 8(b)).

[0048] In addition, by installing step prevention sections 28 at both ends of each cross girder 5 perpendicular to the bridge axis, even if the support body 4A is damaged during an earthquake or other incident and the cross girder 5 shifts from the support body 4A and falls onto the pier 1 together with the end of the updated girder 3, the step that occurs at the boundary between the existing section A and the updated section B can be kept as small as possible.Therefore, by simply installing soil or laying plates (not shown) at the boundary between the existing section A and the updated section B and on the asphalt pavement 9, the area can be quickly restored and emergency vehicles can be allowed to pass through on an emergency basis.

[0049] Furthermore, a water-stopping member 18 that prevents leakage of rainwater and other water at the joint between the side of the upper girder 16 and the end of the existing girder 2 is attached to the side of the upper girder 16 with adhesive, and caulking 18a is filled at the boundaries between the water-stopping member 18 and the existing girder 2 and the upper girder 16 (see Figure 10).

[0050] To explain these configurations in more detail, at the upper end of the pier 1 located at the boundary between the existing section A and the renewed section B, the ends of several renewed girders 3, 3 erected in the direction of the bridge axis are placed on each cross beam 5 at intervals perpendicular to the bridge axis.

[0051] Additionally, upper girder pieces 16a are placed on each of the cross beams 5, 5, which are spaced apart in the direction perpendicular to the bridge axis, and joint board pieces 8b are placed on each of the upper girder pieces 16a. As a result, the upper girders 16 and joint boards 8 are each formed continuously in the direction perpendicular to the bridge axis.

[0052] The upper girder piece 16a is integrally formed into a T-shape in side view, consisting of a beam section 16b formed to a fixed length in the direction perpendicular to the bridge axis and a leg section 16c formed in the center of the beam section 16b. The upper girder piece 16a is also arranged on each cross beam 5 so that the beam section 16b continues in the direction perpendicular to the bridge axis.

[0053] The joint plate pieces 8b are formed to a fixed length in the direction perpendicular to the bridge axis, are placed on top of each upper girder piece 16a, and are detachably attached to the top of each upper girder piece 16a with mounting bolts (not shown).The joints between the beam sections 16b, 16b of each upper girder piece 16a, 16a and the joints between each joint plate piece 8b, 8b are offset in the direction perpendicular to the bridge axis to ensure good adhesion at the joints (see Figure 8(b)).

[0054] The step prevention parts 28 are symmetrically attached to the lower end parts of both ends of each cross beam 5, 5 in the direction perpendicular to the bridge axis (see Figure 8(b)). The step prevention parts 28 are formed from a plurality of laminated plates 28a arranged in a stack on the lower end parts of the cross beam 5, and cushion members 28b made of hard rubber or the like attached to the underside of the laminated plate 28a stacked in the lowest layer (see Figure 10).

[0055] Next, we will explain the method of joining the existing girder 2 and the renewal girder 3 at the upper end of the pier 1, which is located at the boundary between the existing section A where the existing girder 2 is erected and the renewal section B where the renewal girder 3 is erected (see Figures 1, 11 to 18).

[0056] Figure 11(a) illustrates a continuous viaduct consisting of multiple piers 1, 1A spaced apart in the bridge axis direction, and multiple existing girders 2 and renewed girders 3 erected between the piers 1, 1A and between the piers 1A, 1A.

[0057] Figure 11(b) also shows the upper end of pier 1 located at the boundary between existing section A, where existing girder 2 is erected, and updated section B, where existing girder 2 has been removed and updated girder 3 will be erected, in the continuous viaduct shown in Figure 11(a).

[0058] Furthermore, Figures 12 to 18 show a renewal section of the continuous viaduct where the existing girder 2 has been removed. The figure shows the end of the updated girder 3 that will be installed continuously to the existing girder 2.

[0059] (1) At the upper end of the pier 1 shown in Figure 11(b), first, multiple cross girders 5 are placed at intervals perpendicular to the bridge axis at the upper end of the pier 1 in the renewal section B where the existing girder 2 has been removed. In addition, buffer members 17 are installed between each cross girder 5 and the existing girder 3 (see Figures 1, 11, and 15).

[0060] The cross beams 5 are arranged in series along the end faces of the existing girders 2 in a direction perpendicular to the bridge axis, and at a specified interval from each other in the direction perpendicular to the bridge axis (see Figure 15). The buffer members 17 are detachably attached to the sides of the cross beams 5 via mounting brackets 20 using multiple mounting bolts (see Figure 1).

[0061] (2) Next, multiple replacement girders 3 are erected in the replacement section B. The replacement girders 3 are spaced at equal intervals perpendicular to the bridge axis and are erected parallel to the bridge axis. In addition, the erection protrusions 10 at the end of each replacement girder 3 are placed on top of the cross beam 5 and fixed to the cross beam 5 with multiple connecting bolts 11 (see Figure 1).

[0062] (3) Next, a bottom steel plate 12 is laid continuously on top of the renewed girder 3 between adjacent renewed girders 3, 3 in the direction perpendicular to the bridge axis, and multiple cross ribs 13 are laid on top of it parallel to the direction perpendicular to the bridge axis and at equal intervals in the direction of the bridge axis.

[0063] Furthermore, multiple vertical reinforcement bars 14 are arranged in the bridge axis direction on top of the horizontal ribs 13. Then, roadbed concrete 15 is poured on top of the deck steel plate 12 to a thickness that completely buries the horizontal ribs 13 and vertical reinforcement bars 14, forming the renewed roadbed 7.

[0064] Furthermore, if the replacement girder 3, bottom steel plate 12, cross rib 13 and roadbed concrete 15 are formed as a single unit in advance at a factory or the like as a precast composite deck panel unit (panel unit X) of a size and weight that can be laid by heavy machinery such as a crane, these components can be laid in a single construction run, making it possible to significantly reduce the labor required for on-site work.

[0065] (4) Next, the upper girder 16 is erected on top of the cross girder 5 along the end face of the existing girder 2, spanning between the cross girder 5, 5 in a direction perpendicular to the bridge axis (see Figures 14 and 15). In addition, a watertight member 18 is installed between the upper girder 16 and the existing girder 2. The watertight member 18 is detachably attached to the side of the upper girder 16 via mounting brackets 21 using multiple mounting bolts (see Figure 1).

[0066] (5) Next, the joint plate 8 is installed on top of the upper girder 16 (see Figures 1, 13, and 14). The joint plate 8 is detachably attached to the top of the upper girder 16 with multiple mounting bolts 22, and the end 8a on the existing girder 2 side is extended in the bridge axis direction to overlap the upper end surface of the water-stopping member 18 and the upper end surface of the existing girder 2 (existing roadbed 6) (see Figure 1). Then, asphalt pavement 9 is constructed flush with the joint plate 8 on top of the existing roadbed 6 and the renewed roadbed 7 (see Figures 1 and 18).

[0067] Since the existing roadbed 6 is usually paved with asphalt pavement 9, it is only necessary to construct the asphalt pavement 9 on only the area very close to the joint board 8 at the same time as constructing the new roadbed 7.

[0068] The above construction procedure completed the replacement of existing girder 2 with updated girder 3 in updated section B.

[0069] Next, we will explain the construction procedure for replacing the existing section A following the replacement section B (see Figures 19 to 29). Figures 19 to 22 show the end of one replacement section where the replacement of the existing girder with the replacement girder has been completed.

[0070] (1) At the upper end of the pier 1 located at the boundary between the renewed section (ii) where replacement has been completed and the existing section (i), first, a portion of the asphalt pavement 9 and roadbed concrete 15 on the renewed section (ii) side is removed up to the position of the bottom steel plate 12, exposing a certain length of the vertical reinforcement 14 in the renewed roadbed 7.

[0071] (2) Next, the joint board 8, water-stopping member 18, upper girder 16 and buffer member 17, and then the roadbed concrete 6 of existing section A are removed in that order, and then the existing girder 2 is removed.

[0072] (3) Next, a new cross girder 5A is placed between adjacent cross girders 5, 5 (maintenance section 19) perpendicular to the bridge axis, and adjacent cross girders 5, 5A, 5 are joined perpendicular to the bridge axis, forming a continuous cross girder perpendicular to the bridge axis from adjacent cross girders 5, 5A, 5 (see Figures 20, 21, 23).

[0073] (4) Next, multiple shear reinforcement bars 23 are arranged at intervals around the outer periphery of the cross beams 5 and 5A in a direction perpendicular to the bridge axis (see Figures 21, 24, and 29). The shear reinforcement bars 23 are arranged in a continuous L-shape from the upper ends of the cross beams 5 and 5A to the side of the existing section I. In addition, each shear reinforcement bar 23 is welded to the tip of the vertical reinforcement bar 14 in the renewed roadbed 7 exposed above the bottom steel plate 12.

[0074] (5) Next, multiple replacement girders 3 are erected in the existing section A where the existing girder 2 was removed. The replacement girders 3 are spaced at equal intervals perpendicular to the bridge axis and are erected parallel to the bridge axis. In addition, the erection protrusions 10 at the end of each replacement girder 3 are placed on the cross girder 5 or cross girder 5A and fixed to the cross girder 5 or 5A with multiple connecting bolts 11 (see Figure 29).

[0075] (6) Next, a bottom steel plate 12 is laid continuously on top of the renewed girder 3 between adjacent renewed girders 3, 3 in the direction perpendicular to the bridge axis, and multiple cross ribs 13 are laid on top of it parallel to the direction perpendicular to the bridge axis and at equal intervals in the direction of the bridge axis.

[0076] (7) Next, multiple vertical reinforcement bars 14 are arranged in the bridge axis direction on top of the horizontal ribs 13, and multiple shear reinforcement bars 24 are arranged at the upper ends of the horizontal beams 5 and 5A and on the outer periphery of the existing section A side (see Figures 25 and 29). The shear reinforcement bars 24 are arranged in an L-shape from the upper ends of the horizontal beams 5 and 5A to the outer periphery of the renewal section B side, and are arranged symmetrically with the shear reinforcement bars 24. In addition, each shear reinforcement bar 24 is welded to the vertical reinforcement bars 14 and is continuous with the vertical reinforcement bars 14.

[0077] (8) Next, the roadbed concrete 15 is poured on the deck steel plate 12 to a thickness that completely buries the cross ribs 13 and reinforcing bars 14, thereby forming the renewed roadbed 7.

[0078] Furthermore, if the replacement girder 3, bottom steel plate 12, horizontal ribs 13, vertical reinforcement bars 14 and roadbed concrete 15 are integrally formed as a precast composite deck panel unit (panel unit X) in advance at a factory or the like, these components can be laid in a single operation, enabling significant labor savings in on-site work (see Figures 28 and 29).

[0079] In addition, when arranging the shear reinforcement 24, a portion of the roadbed concrete 15 is removed down to the position of the bottom steel plate 12 to expose a certain length of the vertical reinforcement 14 in the renewed roadbed 7, and the shear reinforcement 24 is connected to the end of that exposed portion.

[0080] (9) Next, concrete 25 is continuously poured between the renewal girder 3 in existing section A and the renewal girder 3 in renewal section B from the top surface of the pier 1 to the top surface of the renewal roadbed 7 (see Figures 28 and 29). By pouring concrete 25 between existing section A and renewal section B, a cross girder 26 of SRC structure with cross girder 5 and cross girder 5A made of steel is formed continuously at the top end of the pier 1 in the direction perpendicular to the bridge axis, and this cross girder 26 integrates the multiple renewal girders 3, 3 and multiple panel units XX arranged on both sides of the cross girder 26. [Industrial Applicability]

[0081] The present invention provides excellent running performance and earthquake resistance at the joints between the existing girders and the replacement girders of a continuous viaduct consisting of multiple piers spaced apart and continuous girders or multiple simple girders erected between each pier, as well as excellent maintenance and management such as repair and inspection of the joints, and can efficiently replace the existing girders with replacement girders. [Explanation of symbols]

[0082] 1 Pier, 1A Pier, 2 Existing girder, 3 Renewal girder, 4, 4A Bearing, 5, 5A cross beam, 6 existing roadbed, 7 renewed roadbed, 8 joint board, 8a End of joint board, 8b Joint board piece, 9 Asphalt pavement, 10 erection projection, 11 connecting bolt, 12 bottom steel plate, 13 horizontal rib, 14 Reinforcement bar, 15 Subgrade concrete, 16 Upper girder, 16a upper girder piece, 16b beam part, 16c leg part, 17 buffer member, 18 Water-stopping member, 19 Maintenance space, 20 Mounting hardware, 21 Mounting bracket, 22 Mounting bolt, 23 Shear reinforcement bar, 24 Shear reinforcement, 25 Concrete, 26 Cross beam, 27 RC slab, 28 Step prevention part, 28a Level adjustment plate, 28b Cushion member A. Existing section, B. Renewal section, X panel unit (synthetic floor panel unit).

Claims

1. A joint structure between an existing girder and a replacement girder, which is joined at the upper end of a pier located at the boundary between an existing section where an existing girder is erected and a replacement section where a replacement girder is erected, characterized in that it comprises: a plurality of cross girders arranged at intervals perpendicular to the bridge axis at the upper end of the pier, on which the end of the replacement girder is placed; an upper girder arranged at the upper end of the cross girders in a direction perpendicular to the bridge axis, spanning between the plurality of cross girders; and a joint plate arranged between the end of the existing girder and the end of the replacement girder, fixed to the upper end of the upper girder, with the existing girder side extended in the direction of the bridge axis along the upper surface of the existing girder.

2. A joint structure between an existing girder and a replacement girder as described in claim 1, characterized in that a maintenance and management space is provided at the upper end of the pier to maintain and manage the joint between the existing girder and the replacement girder, consisting of the cross girder and the upper girder.

3. 3. A joint structure between an existing girder and a replacement girder according to claim 1 or 2, characterized in that a buffer member is installed between the cross girder and the existing girder.

4. 3. A joint structure between an existing girder and a replacement girder according to claim 1 or 2, characterized in that a water-stopping member is installed between the upper girder and the existing girder.

5. A joint structure between an existing girder and a replacement girder as described in claim 1 or 2, characterized in that the joint plate is detachably installed at the upper end of the upper girder and is slidably installed on the upper surface of the existing girder.

6. A method for joining an existing girder and an updated girder, which joins the existing girder and the updated girder at the upper end of a pier located at the boundary between the existing section where the existing girder is erected and the updated section where the updated girder will be erected, characterized in that it includes the following steps. (1) A process of placing multiple cross beams at the upper end of the pier along the end of the existing girder and spaced apart from each other in a direction perpendicular to the bridge axis. (2) A process of erecting the renewal girder in the renewal section and placing and fixing the end of the renewal girder on the upper end of the cross girder. (3) A process of aligning the upper girder with the upper end of the cross girder, along the end of the existing girder, and placing it perpendicular to the bridge axis, spanning between the multiple cross girders. (4) A process of installing a joint plate between the end of the existing girder and the end of the updated girder, fixing it to the upper girder, and extending the end of the joint plate in the bridge axis direction along the top surface of the existing girder.

Images