Bridge, bridge superstructure, bridge girder, and bridge construction method

Abstract

To provide a bridge, an upper structure of the bridge, a bridge girder and a construction method of the bridge, for improving durability to tensile stress in the bridge axial direction, while reducing cost and shortening a construction period related to a support by reducing the installation number of supports.SOLUTION: The bridge 100 is characterized in that a lower structure 3 and an upper structure 1 are connected via a bearing 2, and the upper structure 1 includes a plurality of concrete precast girders 12 oriented in a bridge axis direction X and arranged in the bridge axis direction X and a bridge axis right-angled direction Y, and a plurality of concrete binding blocks 11 provided at both ends of each of the plurality of precast girders 12 in the bridge axis direction X and bound to each other by prestress in the bridge axis direction X and the bridge axis right-angled direction Y above the bearing 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bridge in which a substructure and a superstructure are connected via bearings, a superstructure of the bridge, a bridge girder, and a method of constructing the bridge. [Background technology]

[0002] Previously, research has been conducted on the structure of a bridge with seismic isolation, in which a substructure and a superstructure are connected via bearings.

[0003] Patent Document 1 discloses a bridge that includes a precast cross girder installed on a substructure via a bearing device, and multiple precast vertical girders that are erected in parallel on the precast cross girder and integrated with cast-in-place concrete. Patent Document 2 also discloses a bridge that includes a superstructure that has concrete main girders and precast reinforced concrete anchorage blocks, in which the tops of the substructure and the anchorage blocks are fastened in the bridge axis direction, and adjacent anchorage blocks are fastened to each other in the direction perpendicular to the bridge axis. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-256873 [Patent Document 1] Japanese Patent Application Publication No. 2023-118410 Summary of the Invention [Problem to be solved by the invention]

[0005] The bridge disclosed in Patent Document 1, in which multiple precast vertical girders are erected on precast cross girders, requires fewer bearings than when multiple precast vertical girders are connected to the substructure with bearings, thereby reducing costs and labor. However, the bridge disclosed in Patent Document 1 does not disclose a means for resisting tensile stress in the bridge axis direction at the joint area between the precast cross girders and multiple precast vertical girders, leaving room for improvement in the durability of the superstructure of the seismically isolated bridge. Furthermore, the bridge disclosed in Patent Document 2 discloses a means for resisting tensile stress in the bridge axis direction by fastening the top of the substructure to the anchorage blocks in the bridge axis direction. However, this is a so-called rigid frame bridge with earthquake resistance, and cannot be applied to the structure of a seismically isolated bridge. In other words, the bridges disclosed in Patent Documents 1 and 2 have the problem that, while reducing costs and shortening construction time by reducing the number of bearings, they are unable to improve durability against tensile stress in the bridge axis direction for seismically isolated bridges.

[0006] The present invention was devised in consideration of the above-mentioned problems, and its purpose is to provide a bridge, bridge superstructure, bridge girder, and bridge construction method that reduces costs and construction time related to bearings by reducing the number of bearings installed, while also improving durability against tensile stress in the bridge axis direction. [Means for solving the problem]

[0007] The bridge of the first invention is a bridge in which a substructure and a superstructure are connected via supports, and the superstructure is characterized by comprising a plurality of precast concrete girders oriented in the bridge axis direction and arranged in multiple directions along the bridge axis and perpendicular to the bridge axis, and a plurality of concrete fastening blocks provided at both ends of each of the precast girders in the bridge axis direction and fastened to each other by prestressing above the supports in the bridge axis direction and perpendicular to the bridge axis.

[0008] The superstructure of a bridge in the second invention is a superstructure of a bridge connected to a substructure via supports, and is characterized by comprising a plurality of precast concrete girders oriented in the bridge axis direction and arranged in multiple directions along the bridge axis and perpendicular to the bridge axis, and a plurality of concrete fastening blocks provided at both ends of each of the precast girders in the bridge axis direction and fastened to each other by prestress in the bridge axis direction and perpendicular to the bridge axis above the supports.

[0009] The bridge girder in the third invention is a bridge girder that constitutes the superstructure of a bridge and is connected to the substructure via supports, and is characterized by comprising: concrete precast girders that are oriented in the bridge axis direction and arranged in multiple locations in the bridge axis direction and perpendicular to the bridge axis; and concrete fastening blocks that are provided at both ends of the precast girders in the bridge axis direction and are fastened to each other in multiple locations in the bridge axis direction and perpendicular to the bridge axis by prestress above the supports.

[0010] The bridge construction method of the fourth invention is a bridge construction method that connects a substructure and a superstructure via bearings, and is characterized by comprising a bridge girder installation process in which a plurality of bridge girders, each having a plurality of concrete precast girders and fastening blocks attached to both ends of the precast girders in the bridge axis direction, are oriented in the bridge axis direction and arranged in a plurality of directions along the bridge axis and perpendicular to the bridge axis, and a bridge girder fastening process in which concrete is filled between the plurality of bridge girders arranged in the bridge girder installation process, and then, above the bearings, the plurality of fastening blocks are fastened to each other in the bridge axis direction and perpendicular to the bridge axis by prestressing. [Effects of the Invention]

[0011] According to the first and second inventions, the bridge superstructure comprises a plurality of concrete fastening blocks, which are provided at both ends of each of the plurality of precast girders in the bridge axis direction and fastened together by prestress in the bridge axis direction and perpendicular to the bridge axis above the supports. This allows for a reduction in the number of supports compared to when each of the plurality of precast girders is supported by a support. Furthermore, because the multiple fastening blocks are fastened together in the bridge axis direction, the areas where the bridge girders are joined together can more firmly resist tensile stress in the bridge axis direction compared to when they are not fastened together in the bridge axis direction. This reduces the number of supports installed, thereby reducing costs and construction time related to supports, and improving durability against tensile stress in the bridge axis direction.

[0012] According to the third invention, the bridge girder is provided with concrete fastening blocks, which are installed at both ends of the precast girder in the bridge axis direction and are fastened together by prestressing in the bridge axis direction and perpendicular to the bridge axis above the bearings. This allows for a reduction in the number of bearings installed compared to a bridge in which multiple precast girders are supported by individual bearings. Furthermore, because multiple fastening blocks are fastened together in the bridge axis direction, the areas where the bridge girders are joined together can more firmly resist tensile stress in the bridge axis direction compared to when they are not fastened together in the bridge axis direction. This reduces the number of bearings installed, thereby reducing costs and construction time related to bearings, and improving durability against tensile stress in the bridge axis direction.

[0013] According to the fourth aspect of the present invention, a bridge construction method includes a bridge girder fastening step in which, after filling concrete between multiple bridge girders, multiple fastening blocks are fastened to each other in the bridge axis direction and perpendicular to the bridge axis by prestressing above the supports. This allows for a reduction in the number of supports installed compared to when multiple precast girders are supported by individual supports. Furthermore, because multiple fastening blocks are fastened to each other in the bridge axis direction, the areas where the bridge girders are joined can more strongly resist tensile stress in the bridge axis direction compared to when they are not fastened to each other in the bridge axis direction. This reduces the number of supports installed, thereby reducing costs and construction time related to supports, and improving durability against tensile stress in the bridge axis direction. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic perspective view showing an example of a bridge according to the present embodiment. [Figure 2] FIG. 2 is a schematic side view showing an example of a bridge in this embodiment. [Figure 3] FIG. 3 is a schematic cross-sectional view showing an example of the AA cross section of FIG. [Figure 4] FIG. 4 is a schematic cross-sectional view showing an example of the cross section BB in FIG. [Figure 5] FIG. 5 is a schematic perspective view showing an example of a bridge girder that constructs a bridge in this embodiment. [Figure 6] FIG. 6 is a schematic perspective view showing an example of a bridge construction method according to this embodiment. [Figure 7] FIG. 7 is a schematic perspective view showing an example of a bridge construction method according to this embodiment. [Figure 8] FIG. 8 is a schematic perspective view showing an example of a bridge girder installation step that constitutes the bridge construction method according to this embodiment. [Figure 9] FIG. 9 is a partially enlarged view showing an example of a connection region between a bearing and a plurality of bridge girders in the bridge construction method according to this embodiment. [Figure 10] FIG. 10 is a schematic overhead view showing an example of a bridge girder installation step that constitutes the bridge construction method according to this embodiment. [Figure 11] FIG. 11 is a schematic overhead perspective view showing an example of the bridge girder tightening step that constitutes the bridge construction method according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, with reference to the drawings, a bridge 100 as an embodiment of the present invention, a superstructure 1 of the bridge 100, a bridge girder 10, and an example of a method for constructing the bridge 100 will be described in detail. In each drawing, the bridge axis direction is designated as X, one direction perpendicular to the bridge axis direction X is designated as the bridge axis perpendicular direction Y, and the direction perpendicular to both the bridge axis direction X and the bridge axis perpendicular direction Y is designated as the vertical direction Z. The configurations in each drawing are depicted schematically for the purpose of explanation, and for example, the size of each component and the size comparison between components may differ from those in the drawings.

[0016] <Bridge 100> An example of a bridge 100 according to this embodiment will be described with reference to the drawings.

[0017] 1 to 4, the bridge 100 has a superstructure 1, a bearing 2, and a substructure 3, and the substructure 3 and the superstructure 1 are connected via the bearing 2, so that the bridge 100 is a structure with seismic isolation properties, unlike a conventional rigid frame bridge that has earthquake resistance. Note that FIG. 1 is a schematic perspective view showing an example of the bridge 100 in this embodiment, FIG. 2 is a schematic side view showing an example of the bridge 100, and FIGS. 3 and 4 are schematic cross-sectional views showing examples of the AA and BB cross sections of FIG. 2, respectively.

[0018] <Superstructure 1> The superstructure 1 constitutes a bridge 100 and is connected to the top of the substructure 3 via bearings 2. The superstructure 1 is constructed by fastening a plurality of bridge girders 10 oriented in the bridge axis direction X to one another using vertical fastening parts 4 and horizontal fastening parts 5, and concrete filler parts 6 are poured between the plurality of bridge girders 10. The superstructure 1 comprises a plurality of concrete fastening blocks 11 that connect the plurality of bridge girders 10 to the top of the substructure 3 via bearings 2, and a plurality of concrete precast girders 12 that are connected at both ends to the fastening blocks 11, are oriented in the bridge axis direction X, and are arranged in the bridge axis direction X and the direction perpendicular to the bridge axis Y.

[0019] Here, the multiple fastening blocks 11 are fastened to each other above the bearings 2 in the bridge axis direction X by one or more vertical fastening parts 4 through prestress. Additionally, the multiple fastening blocks 11 are fastened to each other above the bearings 2 in the direction perpendicular to the bridge axis Y by one or more horizontal fastening parts 5 through prestress. In this case, the number of installed bearings can be reduced compared to when multiple precast girders 12 are supported by individual bearings 2. Furthermore, because the multiple fastening blocks 11 are fastened to each other in the bridge axis direction X, the areas where the bridge girders 10 are joined together can more firmly resist tensile stress in the bridge axis direction X compared to when they are not fastened to each other in the bridge axis direction X. This reduces the number of installed bearings, thereby reducing costs and construction time related to the bearings 2, and improving durability against tensile stress in the bridge axis direction X.

[0020] <Bridge girder 10> As shown in Fig. 5, for example, a bridge girder 10 includes a concrete precast girder 12 and concrete tie-down blocks 11 provided at both ends of the precast girder 12. The bridge girder 10 is formed, for example, by integrally molding the tie-down blocks 11 and the precast girder 12 as a PCaPC girder. For example, if the weight of the tie-down blocks 11 and the precast girder 12 becomes too heavy to transport or lift using a crane, the tie-down blocks 11 and the precast girder 12 may be assembled on-site as separate precast members. For example, the tie-down blocks 11 may be formed by pouring concrete on both ends of the precast girder 12 and casting it in place.

[0021] As shown in Figures 1 to 4, for example, multiple bridge girders 10 are oriented in the bridge axis direction X, and each of the fastening blocks 11 is prestressed and fastened to each other in the bridge axis direction X by vertical fastening parts 4, and prestressed and fastened to each other in the direction perpendicular to the bridge axis Y by horizontal fastening parts 5. In this case, the number of bearings installed for the bridge 100 can be reduced compared to when multiple precast girders 12 are supported by respective bearings 2. Also, because multiple fastening blocks 11 are fastened to each other in the bridge axis direction X, the areas where the bridge girders 10 are joined together can more firmly resist tensile stress in the bridge axis direction X compared to when they are not fastened to each other in the bridge axis direction X. This reduces the number of bearings installed, thereby reducing costs and construction time related to the bearings 2, and improving durability against tensile stress in the bridge axis direction X.

[0022] <Knot Block 11> The fastening block 11 is a concrete block of approximately rectangular parallelepiped or cubic shape made of a known concrete material. The fastening block 11 is installed on the substructure 3 via supports 2. The fastening block 11 may be integrally formed with the precast girder 12, or may be formed by being cast in place relative to the precast girder 12.

[0023] The binding block 11 is made up of a block body 110, as shown in Fig. 5, for example. The binding block 11 is formed by cutting out, in advance, first recesses 111 for attaching the vertical binding parts 4 and second recesses 112 for attaching the horizontal binding parts 5 in the surface of the block body 110. The binding block 11 is formed, in advance, with first perforations 111a for inserting the vertical binding parts 4 therein and second perforations 112a for inserting the horizontal binding parts 5 therein.

[0024] As shown in Figures 2 and 4, for example, a plurality of fastening blocks 11 are arranged in the bridge axis direction X, with filler sections 6 cast between them to form an integrated unit, and then fastened in the bridge axis direction X. Also, as shown in Figures 3 and 4, a plurality of fastening blocks 11 are arranged in the direction Y perpendicular to the bridge axis, with filler sections 6 cast between them to form an integrated unit, and then fastened in the bridge axis direction Y.

[0025] In this regard, in the conventional construction method in which multiple precast main girders oriented in the bridge axis direction X are erected on precast cross girders oriented in the direction transverse to the bridge axis Y, it was necessary to adjust the length of the precast cross girders according to the spacing of the substructures 3 in the direction transverse to the bridge axis Y. However, by using the fastening blocks 11 of the present invention, the number of fastening blocks can be adjusted and then fastened together, allowing the bridge 100 to easily accommodate various spacings between the substructures 3 while retaining the functionality of conventional precast cross girders. This improves convenience when constructing the bridge 100. Furthermore, in the conventional construction method in which precast cross girders and precast main girders are joined only with cast-in-place concrete, there was room for improvement in the durability against tensile stress between each girder. However, by using the fastening blocks 11 of the present invention, prestress can be easily applied between each girder in the bridge axis direction X and the direction transverse to the bridge axis Y using the vertical fastening parts 4 and horizontal fastening parts 5. This improves durability against tensile stress in the bridge axis direction X.

[0026] 5 illustrates a fastening block 11 in which the recesses 111, 112 and the perforations 111a, 112a are formed in two stages in the vertical direction Z, but three or more stages may be formed in the vertical direction Z. In this case, in order to more uniformly introduce prestress in the bridge axis direction X and the direction perpendicular to the bridge axis Y into the block body 110, it is preferable that the vertical fastening portions 4 and the horizontal fastening portions 5 are inserted alternately in the vertical direction Z. For this reason, it is preferable that the perforations 111a, 112a are formed so that the internal hollow spaces are alternately formed in the vertical direction Z inside the block body 110. Furthermore, the fastening block 11 may have the recesses 111, 112 and the perforations 111a, 112a formed in multiple stages in the horizontal direction.

[0027] The fastening blocks 11 may have protruding or recessed shear keys 113 formed on the surfaces of the block body 110, for example, on the opposing faces where multiple fastening blocks 11 face each other. In this case, the fastening blocks 11 are prevented from shifting horizontally against the filling section 6 due to shear force, thereby improving the shear resistance of the bridge 100. This improves the durability of the bridge 100.

[0028] The shear keys 113 may be formed on the surface of the block body 110 in multiple stages in the vertical direction Z or horizontal direction. The shear keys 113 may be formed to bulge, for example, in the bridge axis direction X, or in the direction perpendicular to the bridge axis Y (see shear key 113' in Figure 9). The shape of the shear keys 113 may be, for example, a truncated quadrangular pyramid with a generally trapezoidal cross section, a pyramid with a generally triangular cross section, or a rectangular parallelepiped with a generally rectangular cross section.

[0029] <Precast girder 12> The precast girder 12 has a shape that extends in one direction, as shown in Fig. 5, for example, and has fastening blocks 11 provided at both ends in the extension direction. The precast girder 12 is, for example, a known PCa (Precast Concrete) girder that is produced in advance in a factory or the like, and a PCaPC (Precast-Prestressed Concrete) girder may also be used. In this embodiment, Figs. 1 to 4 show an example in which a PCaPC girder that is a T-girder that is approximately T-shaped in cross section in the bridge axis direction X is used, but a hollow girder that is approximately square-shaped in cross section in the bridge axis direction X may also be used.

[0030] As shown in Figure 1, for example, the precast girders 12 are oriented in the bridge axis direction X and are arranged in multiple locations in the bridge axis direction X and the direction perpendicular to the bridge axis Y. The multiple precast girders 12 are fastened to each other in the direction perpendicular to the bridge axis Y, for example, by horizontal fastening parts 5'. For this reason, as shown in Figure 5, for example, the precast girders 12 have third drilled holes 12a drilled on the surface in the direction perpendicular to the bridge axis Y for inserting the horizontal fastening parts 5' in the direction perpendicular to the bridge axis Y. The multiple precast girders 12 are integrated by pouring filler parts 6 between them, and then fastened to each other in the direction perpendicular to the bridge axis Y, as shown in Figure 3, for example.

[0031] In the example of Figure 5, a precast girder 12 is shown in which multiple third drill holes 12a are formed in one row in the vertical direction Z along the extension direction of the precast girder 12, but multiple rows may be formed in the vertical direction Z.

[0032] <Support 2> The bearing 2 is provided on the substructure 3 and supports the superstructure 1 from below. As the bearing 2, for example, a known bearing device provided between the substructure 3 and the superstructure 1 of the bridge 100 is used.

[0033] <Substructure 3> The substructure 3 is a structure that supports the superstructure 1 from below. The substructure 3 is made up of, for example, multiple piers and abutments made of cast-in-place reinforced concrete. The substructure 20 is constructed such that both ends of the bridge girder 10 of the superstructure 1 are erected on the multiple piers or on the piers and abutments.

[0034] <Vertical binding part 4> The vertical fastening portion 4 is a member for fastening a plurality of fastening blocks 11 together in the bridge axis direction X. The vertical fastening portion 4 includes, for example, vertical tendons 41 and vertical fastening members 42.

[0035] 2, for example, the vertical fastening portion 4 is formed by fastening both ends of a vertical tension member 41 inserted into a hollow space (first borehole 111a) shown by a dashed line to two block bodies 110 arranged in the bridge axis direction X by vertical fastening members 42 in a state where prestress is applied in each of the first recesses 111. In this way, the vertical fastening portion 4 can fasten a plurality of fastening blocks 11 in the bridge axis direction X by prestressing.

[0036] 2 and 4, the vertical fasteners 42 are preferably stored in the first recesses 111. In this case, the vertical fasteners 42 are less susceptible to the external environment, deterioration of the vertical fastening parts 4 is suppressed, and a decrease in the prestress force in the bridge axis direction X is suppressed. This makes it possible to suppress a decrease in the durability of the bridge 100.

[0037] As the vertical tendons 41, for example, PC steel, carbon fiber composite cables, or other materials having a tensile force capable of introducing a predetermined prestress can be used.

[0038] <Horizontal binding part 5, 5'> The horizontal fastening portion 5 is a member for fastening a plurality of fastening blocks 11 together in the direction Y perpendicular to the bridge axis. The horizontal fastening portion 5 includes, for example, horizontal tendons 51 and horizontal fastening members 52.

[0039] 3, for example, the horizontal fastening portion 5 is formed by fastening both ends of horizontal tendons 51 inserted into hollow spaces (second boreholes 112a) shown by dashed lines to multiple block bodies 110 arranged in the direction Y perpendicular to the bridge axis by horizontal fasteners 52, 52 in a state where prestress is applied in each of the second recesses 112, 112. In this way, the horizontal fastening portion 5 can fasten multiple fastening blocks 11 in the direction Y perpendicular to the bridge axis by prestressing.

[0040] It is preferable that the horizontal fasteners 52 are stored in the second recesses 112, as shown in Figures 3 and 4. In this case, the horizontal fasteners 52 are less susceptible to the external environment, deterioration of the horizontal fastening parts 5 is suppressed, and a decrease in the prestress force in the direction Y perpendicular to the bridge axis is suppressed. This makes it possible to suppress a decrease in the durability of the bridge 100.

[0041] The horizontal tendons 51 may be made of the same material as the vertical tendons 41, for example.

[0042] The horizontal fastening parts 5' are components for fastening multiple precast girders 12 to each other in the direction Y perpendicular to the bridge axis. The horizontal fastening parts 5' have the same configuration and function as the horizontal fastening parts 5, for example, and can fasten multiple precast girders 12 to each other in the direction Y perpendicular to the bridge axis by prestressing.

[0043] <Jumping part 6> The filler section 6 is, for example, a concrete member cast in place. The filler section 6 is provided above the bearing 2 and between the multiple fastening blocks 11, and connects and integrates the multiple fastening blocks 11 in the bridge axis direction X and the direction perpendicular to the bridge axis Y. The filler section 6 is cast, for example, by solidifying known ready-mix concrete.

[0044] The filler portion 6 is cast in place so as to contact the shear key 113 that bulges in the bridge axis direction X, as shown in Figures 2 and 4. In this case, it is possible to resist the shear force that occurs between the filler portion 6 and the fastening block 11.

[0045] The filler portion 6 is cast in place, for example, above the fastening block 11 to a height that is approximately flush with the upper end of the precast girder 12. Here, even when the shear key 113 is provided on the upper surface of the fastening block 11, it can also withstand the shear force that occurs between the filler portion 6 and the fastening block 11.

[0046] (Bridge 100 Construction Method) Next, an example of a method for constructing the bridge 100 according to this embodiment will be described with reference to the drawings. The method for constructing the bridge 100 includes, for example, a temporary support structure construction step, a bridge girder installation step, and a bridge girder fastening step.

[0047] <Temporary support structure construction process> In the temporary support structure construction process, workers construct multiple substructures 3 along the bridge axis direction X and the direction perpendicular to the bridge axis Y, as shown in Figure 6. The example in Figure 6 shows a case where two supports 2 are installed on each of the top surfaces of four substructures 3.

[0048] Thereafter, as shown in FIG. 7, for example, workers construct a temporary support structure so that it is spaced apart from the bearings 2 and erected on two substructures 3 arranged in the direction Y perpendicular to the bridge axis. The temporary support structure is a temporary structure that supports the multiple fastening blocks 11 from below in the stage prior to fastening the multiple fastening blocks 11 together, and is removed before the construction method for the bridge 100 is completed. Note that workers may construct the temporary support structure so that it is erected on two existing substructures 3, in which case construction of the substructure 3 in this process may be omitted. In the temporary support structure construction process, workers construct multiple temporary support structures required to erect the bridge girders 10 in the bridge girder installation process described below.

[0049] The temporary support structure consists of, for example, multiple temporary support members and supports that support them from below. The temporary support members can be, for example, known support members with jacks. The supports can be, for example, structures constructed by joining multiple steel frames on-site. In the example of the temporary support structure shown in Figure 7, two steel frames oriented in the direction perpendicular to the bridge axis Y are installed on the substructure 3 at a distance from the support 2, and twelve steel frames oriented in the bridge axis direction X are joined to the support 2 at a distance from the support 2 to form the support. Approximately 44 temporary support members are attached to the constructed support. The structure of the support members and the number of temporary support members can be arbitrarily set as long as they satisfy the conditions for supporting the bridge girder 10 that will be installed in a subsequent process.

[0050] <Bridge girder installation process> In the bridge girder installation process, the worker orients the bridge girders 10 in the bridge axis direction X and installs a plurality of bridge girders 10 in the bridge axis direction X and the direction Y perpendicular to the bridge axis.

[0051] First, as shown in Figure 8, for example, the worker orients the bridge girder 10 in the bridge axis direction X, and then arranges multiple bridge girders 10 in order in the direction perpendicular to the bridge axis Y so that they are erected on two supports 2 and a temporary support structure.

[0052] Next, as shown in Fig. 9, for example, the worker orients the bridge girders 10 in the bridge axis direction X and arranges multiple bridge girders 10 on the supports 2 and temporary support structure in the bridge axis direction X. Note that the order in which the multiple bridge girders 10 are arranged may be arbitrary.

[0053] Here, when fastening blocks 11, 11 each having fitting portions 114, 114' formed by, for example, cutting a single plate in half are arranged facing each other in the bridge axis direction X, workers may arrange multiple fastening blocks 11 so that the fitting portions 114, 114' fit together on the bearing 2. In this case, similar to the function of the shear key 113, it is possible to resist the shear force generated between the fastening blocks 11. This improves the durability of the bridge 100.

[0054] After completing the installation of the multiple bridge girders 10, the worker inserts and places first sheath tubes 111b through multiple first bore holes 111a drilled in advance in two fastening blocks 11 arranged in the bridge axis direction X, as shown in FIG. 10 . The worker also inserts and places second sheath tubes 112b through multiple second bore holes 112a drilled in advance in multiple fastening blocks 11 arranged in the direction perpendicular to the bridge axis Y. The worker then inserts and places third sheath tubes 12b through multiple third bore holes 12a drilled in advance in multiple precast girders 12 arranged in the direction perpendicular to the bridge axis Y. The worker then places reinforcing bars R in the space on the top surface of each block body 110 of the multiple bridge girders 10, which is lower than the top ends of the precast girders 12, and places third sheath tubes 12b in the space inside the reinforcing bars R.

[0055] <Bridge girder tightening process> In the bridge girder tightening process, workers cast the filler sections 6 between the multiple bridge girders 10 that were installed in the bridge girder installation process, as shown in Fig. 11 , for example. After that, workers insert vertical tendons 41 into the first sheath pipes 111b that were inserted into the first boreholes 111a and buried in the filler sections 6, and fasten both ends of the pipes with vertical fastening members 42. In addition, workers insert horizontal tendons 51 into the second sheath pipes 112b that were inserted into the second boreholes 112a and buried in the filler sections 6, and fasten both ends of the pipes with horizontal fastening members 52.

[0056] After that, workers apply prestress in the bridge axis direction X between two fastening blocks 11 arranged in the bridge axis direction X by post-tensioning using vertical tendons 41. In addition, workers apply prestress in the bridge axis direction Y by post-tensioning using horizontal tendons 51 between multiple fastening blocks 11 arranged in the bridge axis direction Y by transverse direction Y. Furthermore, similarly, for the horizontal fastening section 5', after inserting it into the third sheath pipe 12b inserted into the third borehole 12a and buried in the filling section 6, prestress in the bridge axis direction Y is applied by post-tensioning.

[0057] That is, in the bridge girder fastening process, concrete is filled between the multiple bridge girders 10, and then multiple fastening blocks 11 are fastened to each other by prestressing above the bearings 2 in the bridge axis direction X and the direction perpendicular to the bridge axis Y. In this case, the number of bearings installed for the bridge 100 can be reduced compared to when multiple precast girders 12 are supported by bearings 2. Also, because the multiple fastening blocks 11 are fastened to each other in the bridge axis direction X, the areas where the bridge girders 10 are joined to each other can more firmly resist tensile stress in the bridge axis direction X compared to when they are not fastened in the bridge axis direction X. This reduces the number of bearings installed, thereby reducing costs and construction time related to the bearings 2, and improving durability against tensile stress in the bridge axis direction X.

[0058] After the bridge girder tightening process is completed, workers disassemble and remove the temporary support structure. At this time, the superstructure 1 is released from support by the temporary support structure and is supported from below only by the supports 2.

[0059] The method for constructing the bridge 100 is completed through the above steps.

[0060] According to this embodiment, the superstructure 1 of the bridge 100 includes a plurality of concrete fastening blocks 11, which are provided at both ends of each of a plurality of precast girders 12 in the bridge axis direction X and a direction perpendicular to the bridge axis Y above the bearings 2 and are fastened to each other by prestress in the bridge axis direction X and the direction perpendicular to the bridge axis Y. This allows for a reduction in the number of installed bearings compared to when each of the precast girders 12 is supported by a bearing 2. Furthermore, because the multiple fastening blocks 11 are fastened to each other in the bridge axis direction X, the areas where the bridge girders 10 are joined together can more firmly resist tensile stress in the bridge axis direction X compared to when they are not fastened in the bridge axis direction X. This reduces the number of installed bearings, thereby reducing costs and construction time related to the bearings 2, and also improving durability against tensile stress in the bridge axis direction X.

[0061] Furthermore, according to this embodiment, the bridge girder 10 includes concrete fastening blocks 11, which are provided at both ends of the precast girders 12 in the bridge axis direction X and a direction perpendicular to the bridge axis Y above the bearings 2 and are fastened to each other by prestress in the bridge axis direction X and the direction perpendicular to the bridge axis Y. This allows for a reduction in the number of bearings installed for the bridge 100 compared to when multiple precast girders 12 are supported by bearings 2. Furthermore, because multiple fastening blocks 11 are fastened to each other in the bridge axis direction X, the areas where the bridge girders 10 are joined together can more firmly resist tensile stress in the bridge axis direction X compared to when they are not fastened to each other in the bridge axis direction X. This reduces the number of bearings installed, thereby reducing costs and construction time related to the bearings 2, and improving durability against tensile stress in the bridge axis direction X.

[0062] Furthermore, according to this embodiment, the method for constructing the bridge 100 includes a bridge girder fastening step in which, after filling concrete between the bridge girders 10, multiple fastening blocks 11 are fastened to each other by prestressing above the bearings 2 in the bridge axis direction X and the direction perpendicular to the bridge axis Y. This allows for a reduction in the number of bearings installed for the bridge 100 compared to when multiple precast girders 12 are supported by bearings 2. Furthermore, because the multiple fastening blocks 11 are fastened to each other in the bridge axis direction X, the areas where the bridge girders 10 are joined can more firmly resist tensile stress in the bridge axis direction X compared to when they are not fastened to each other in the bridge axis direction X. This reduces the number of bearings installed, thereby reducing costs and construction time related to the bearings 2, and improving durability against tensile stress in the bridge axis direction X.

[0063] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0064] 100 Bridges 1 Superstructure 10 Bridge girders 11. Tightening Block 110 Block Letters 111 First recess 111a 1st drilling 111b First sheath tube 112 Second recess 112a 2nd drilling 112b Second sheath tube 113, 113' shear key 114, 114' fitting part 12 Precast girders 12a 3rd hole 12b Third sheath tube 2 Bearing 21 Fitting receiving part 3 Substructure 4 Vertical knot 41 Longitudinal tendon 42 Vertical fastener 5, 5' Lateral tie 51 Lateral tension members 52 Horizontal fastener 6 Filling section R rebar X Bridge axis direction Y Direction perpendicular to bridge axis Z vertical direction

Claims

1. A bridge in which a substructure and a superstructure are connected via supports, The superstructure comprises: A plurality of precast concrete girders oriented in the bridge axis direction and arranged in the bridge axis direction and perpendicular to the bridge axis; A plurality of concrete fastening blocks are provided at both ends of each of the plurality of precast girders in the bridge axis direction, and are fastened to each other by prestressing in the bridge axis direction and in the direction perpendicular to the bridge axis above the supports; To be prepared A bridge characterized by:

2. A superstructure of a bridge connected to a substructure via a bearing, A plurality of precast concrete girders oriented in the bridge axis direction and arranged in the bridge axis direction and perpendicular to the bridge axis; A plurality of concrete fastening blocks are provided at both ends of each of the plurality of precast girders in the bridge axis direction, and are fastened to each other by prestressing in the bridge axis direction and in the direction perpendicular to the bridge axis above the supports; To be prepared The superstructure of the bridge is characterized by:

3. A bridge girder that constitutes the superstructure of a bridge connected to the substructure via a bearing, A plurality of concrete precast girders are oriented in the bridge axis direction and arranged in the bridge axis direction and perpendicular to the bridge axis; A plurality of concrete fastening blocks are provided at both ends of the precast girder in the bridge axis direction, and fastened together by prestress in the bridge axis direction and perpendicular to the bridge axis direction above the support. To be prepared A bridge girder characterized by:

4. A method for constructing a bridge in which a substructure and a superstructure are connected via supports, comprising: a bridge girder installation process in which a plurality of bridge girders, each having a plurality of concrete precast girders and fastening blocks provided at both ends of the precast girders in the bridge axis direction, are oriented in the bridge axis direction and arranged in the bridge axis direction and perpendicular to the bridge axis; a bridge girder fastening process in which concrete is filled between the bridge girders arranged in the bridge girder arrangement process, and then the multiple fastening blocks are fastened to each other by prestressing above the supports in the bridge axis direction and in the direction perpendicular to the bridge axis; To be prepared A bridge construction method characterized by:

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