Rigid connection structure for upper and lower joints, bridge pier, method for constructing a rigid connection structure for upper and lower joints

Abstract

To provide: a rigid connection structure of upper and lower joint parts, capable of being constructed in a short period of time without becoming an overcrowded reinforcement and rigidly connecting an upper structure and a lower structure of a bridge without becoming a weak point in quality and structure; a bridge pier used therefor; and a method for constructing the rigid connection structure of upper and lower joint parts.SOLUTION: In a rigid connection structure 1 of upper and lower joint parts for rigidly connecting an upper structure 3 and a lower structure 2 of a bridge B1, the upper structure 3 is provided with a precast reinforced concrete-made main girder 30 and a precast reinforced concrete-made or cast-in-place anchoring block 31; the lower structure 2 is provided with a top part 21 rising up to the height of the upper surface of the main girder 30 as it is without reducing the cross-sectional area of the horizontal cross-section even at the upper part, and a main girder receiving base 22 projecting from the side surface in a bridge axial direction X and having the main girder mounted thereon; and the anchoring block 31 and the top part 21 are bound by applying prestress by a bridge-axis direction tension member 7 in the bridge-axis direction X as well as the anchoring block 31 and the main girder 30 are bound by applying prestress by a horizontal tightening tendon 8 in a bridge-axis orthogonal direction Y.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a rigid connection structure of an upper and lower joint that rigidly connects an upper structure and a lower structure of a bridge, a pier thereof, and a method for constructing the rigid connection structure of the upper and lower joint.

Background Art

[0002] Regarding the conventional two-point support connection girder structure, the applicant has proposed a bridge provided with precast cross girders and precast longitudinal girders described in Patent Document 1.

[0003] The bridge described in Patent Document 1 is provided with a precast cross girder 1 on a lower structure 4 so as to extend in a direction perpendicular to the bridge axis via a support device 5 at one point when viewed in a direction perpendicular to the bridge axis. The precast cross girder 1 is continuous in the direction perpendicular to the bridge axis and has a longitudinal girder support flange 6 that projects in the bridge axis direction. A plurality of precast longitudinal girders 2 are erected in parallel across the longitudinal girder support flanges 6 of the opposing precast cross girders 1 at intervals. The precast cross girder 1 and the ends of each precast longitudinal girder 2 are integrated by concrete 8 placed across the ends of each precast longitudinal girder 2 (see Claim 1 of the claims of Patent Document 1, paragraphs

[0012] to

[0016] of the specification, FIG. 1 of the drawings, etc.).

[0004] Thus, the bridge described in Patent Document 1 can reduce the number of expensive supports between the bridge girder and the pier by providing the precast cross girder 1, thereby reducing costs and shortening the construction period. However, by rigidly connecting the upper structure and the lower structure of the bridge to form a ramen structure, it is required to further reduce the number of supports, improve the seismic performance of the entire bridge, and improve the maintainability.

[0005] However, in the rigid frame structure of the connecting girders, the following problems arose with the upper and lower joints that rigidly connect the superstructure and substructure of the bridge: (1) The upper and lower joints, which are rigid connections, require dense reinforcement, resulting in a complex connection structure between the vertical reinforcement of the piers and the axial reinforcement of the main girders. (2) The dense reinforcement of the upper and lower joints makes the construction method complicated and time-consuming. (3) In the conventional structure of the upper and lower joints, both the horizontal construction joint surface between the main girders and piers and the vertical construction joint surface between the main girders themselves are reinforcement splices, which poses a high risk of becoming a weakness in quality and structure.

[0006] Furthermore, as a technique for joining PCaPC girders and bridge piers by applying prestress, for example, Patent Document 2 discloses a bridge pier in which a precast reinforced concrete pier top member (abutment beam 4) equipped with a beam support jaw 8 is tightly connected to the top of a PCa bridge pier (precast concrete column 3), precast concrete girders 5 and 6 are erected between the beam support jaws 8 via supports 10, and the ends of the precast concrete girders 5 and 6, which are placed on the beam support jaws 8 of the abutment beam 4, are tightly connected to the pier top member (abutment beam 4) by a lower tensioning member 11 and an upper tensioning member 12 that penetrate the beam support jaws 8 (see Claim 1 of the claims, paragraphs

[0012] to

[0014] of the specification, and Figures 1 to 5 of the drawings of Patent Document 2).

[0007] Furthermore, Patent Document 3 discloses a structure for connecting bridge girders (girder bridges 4) erected on multiple bridge piers 1 installed over multiple spans, wherein a convex column head 3 is integrally provided on the bridge pier 1, and bridge girders (girder bridges 4) installed on both sides of the convex column head 3 are connected by PC steel members 8 that penetrate the convex column head 3, and the convex column head 3 and the girder bridges 4 are rigidly connected integrally by applying prestress by tensioning and anchoring the PC steel members 8 (see Claim 1 of the claims, paragraphs

[0012] to

[0014] of the specification, and Figures 1 to 5 of the drawings of Patent Document 3).

[0008] However, the bridge described in Patent Document 2 has a bearing 10 made of hard rubber or the like interposed between the bridge girder and the pier top member (abutment beam 4) of the bridge pier, and the bridge described in Patent Document 3 has a bridge girder (girder bridge 4) placed on the bridge pier 1 via a bearing 7. For this reason, neither the bridges described in Patent Documents 2 nor 3 reduce the number of bearings, and these bearings still need to be inspected or replaced periodically, so they do not lead to an improvement in maintainability. Furthermore, since they are rigidly connected via bearings, they do not contribute to improving the seismic performance of the bridge as a whole.

[0009] Furthermore, the bridge described in Patent Document 3 has a convex column head 3 at the top of the pier 1, which makes the anchoring process for the main reinforcement extending vertically complicated, and further dense reinforcement at the upper and lower joints is expected, making it difficult to realize. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Patent No. 5367297 [Patent Document 2] Japanese Patent Publication No. 2001-172913 [Patent Document 3] Patent No. 5539554 [Overview of the project] [Problems that the invention aims to solve]

[0011] Therefore, the present invention was devised in view of the aforementioned problems, and its objective is to provide a rigid connection structure for a vertical joint that can rigidly connect the superstructure and substructure of a bridge without excessive reinforcement, can be constructed in a short period of time, does not result in weaknesses in quality or structure, a bridge pier used therefor, and a method for constructing a rigid connection structure for a vertical joint. [Means for solving the problem]

[0012] The rigid connection structure for an upper and lower joint according to claim 1 is a rigid connection structure for an upper and lower joint that rigidly connects the superstructure and the substructure of a bridge, wherein the superstructure comprises a main girder made of precast reinforced concrete and anchoring blocks made of precast reinforced concrete or cast in place, and the substructure comprises a top portion that rises up to the height of the upper surface of the main girder without the cross-sectional area of ​​the horizontal section decreasing upward, and a main girder support base that protrudes from the side in the direction of the bridge axis and on which the main girder is placed, wherein the anchoring block and the top portion are fastened together by applying prestress with axial tensioning members along the direction of the bridge axis, and the anchoring block and the main girder are fastened together by applying prestress with lateral tensioning members in the direction perpendicular to the bridge axis, and the upper and lower joints are rigidly connected by applying prestress in two directions with tensioning members.

[0013] The rigid connection structure of the upper and lower joint according to claim 2 is characterized in that, in the rigid connection structure of the upper and lower joint according to claim 1, a convex portion is formed on one of the joint surfaces between the anchoring block and the top portion, and a recess that fits with this convex portion is formed on the other, thereby forming a shear key in the bridge axis direction.

[0014] The rigid connection structure for the upper and lower joint according to claim 3 is characterized in that, in the rigid connection structure for the upper and lower joint according to claim 1 or 2, a convex portion is formed on one of the joint surfaces between the anchoring block and the main girder and / or the joint surfaces between the anchoring blocks, and a recess that fits with this convex portion is formed on the other, thereby forming a shear key perpendicular to the bridge axis.

[0015] The rigid connection structure of the upper and lower joint according to claim 4 is characterized in that, in the rigid connection structure of the upper and lower joint according to any one of claims 1 to 3, the anchoring block and the top portion are provided with multiple upper and lower axial tension members along the axial direction of the bridge, the upper axial tension members are prestressed, and the lower axial tension members are not prestressed.

[0016] The rigid connection structure of the upper and lower joint according to claim 5 is the rigid connection structure of the upper and lower joint according to any one of claims 1 to 4, mainThe upper surface of the girder support is provided with a connecting steel member that protrudes upward, main The girder support and the anchoring block are integrated together via the connecting steel material.

[0017] The pier according to claim 6 is a pier that constitutes a rigid connection structure for an upper and lower joint according to any one of claims 1 to 5, and is characterized by comprising a top portion that rises up to the height of the upper surface of the main girder without a reduction in the cross-sectional area of ​​the horizontal section, and a main girder support base that protrudes from the side and on which the main girder is placed.

[0018] The method for constructing a rigid connection structure for an upper and lower joint according to claim 7 is a method for constructing a rigid connection structure for an upper and lower joint that rigidly connects a superstructure having a main girder made of precast reinforced concrete of a bridge and a substructure having piers, comprising a pier construction step of constructing a plurality of piers, each having a top portion that rises up to the height of the upper surface of the main girder without the cross-sectional area of ​​the horizontal section decreasing upwards, and a main girder support base that protrudes from the side in the direction of the bridge axis on which the main girder is placed, and the main girder being mounted between the plurality of main girder support bases The invention is characterized by comprising: a main girder erection process in which the girder is erected by laying it across the bridge; an anchoring block installation process in which precast reinforced concrete anchoring blocks are placed on the main girder support base or concrete is poured in-situ into formwork on the main girder support base to construct the anchoring blocks; and a fastening process in which the anchoring blocks and the top portion are fastened together by applying prestress with axial tensioning members along the bridge axis, and the anchoring blocks and the main girder are fastened together by applying prestress with lateral tensioning members along the direction perpendicular to the bridge axis.

[0019] The method for constructing a rigid connection structure for an upper and lower joint according to claim 8 is characterized in that, in the method for constructing a rigid connection structure for an upper and lower joint according to claim 7, in the fastening step, a protrusion is formed on one of the joint surfaces of the anchoring block and the top portion, and a recess that fits with this protrusion is formed on the other to form a bridge axial shear key and fasten the connection.

[0020] The method for constructing the rigid connection structure of the upper and lower joint parts according to claim 9 is the method for constructing the rigid connection structure of the upper and lower joint parts according to claim 7 or 8, wherein in the tightening process, a convex part is formed on either the joint surface of the fixing block and the main girder, a concave part that fits with the convex part is formed on the other, and a shear key in the direction perpendicular to the bridge axis is formed and tightened.

[0021] The method for constructing the rigid connection structure of the upper and lower joint parts according to claim 10 is the method for constructing the rigid connection structure of the upper and lower joint parts according to any one of claims 7 to 9, wherein in the tightening process, the fixing block and the top part are tightened with a plurality of upper and lower tension members in the bridge axis direction along the bridge axis direction, prestress is applied to the upper tension member in the bridge axis direction, and no prestress is applied to the lower tension member in the bridge axis direction.

[0022] The method for constructing the rigid connection structure of the upper and lower joint parts according to claim 11 is the method for constructing the rigid connection structure of the upper and lower joint parts according to any one of claims 7 to 10, wherein main On the upper surface of the girder support, a connecting steel member protruding upward is provided, and in the fixing block installation process, main The girder support and the fixing block are connected and integrated with the connecting steel member.

Advantages of the Invention

[0023] According to the invention according to claims 1 to 11, in the structure of the conventional connecting girder, the upper and lower joint parts that were over-dense steel bars will not be over-dense steel bars. Also, since it can be joined only by tightening precast members manufactured outside the site, the construction at the site can be completed in a short time. Furthermore, since it does not become over-dense steel bars and, unlike joining with conventional steel bar joints, concrete can be properly compacted and filled in the factory without being affected by the weather, the upper and lower joint parts do not become weaknesses in the quality and structure of the bridge, and can be made of extremely high quality.

[0024] Particularly, according to the inventions according to claims 2 and 8, since a shear key in the bridge axis direction is provided, the shear force resistance in the bridge axis direction of the upper and lower joint parts and the entire bridge is improved.

[0025] In particular, according to the inventions of claims 3 and 9, since a shear key perpendicular to the bridge axis is provided, the shear force resistance in the direction perpendicular to the bridge axis is improved for the upper and lower joints and for the entire bridge.

[0026] In particular, according to the inventions of claims 4 and 10, since no prestress is applied to the lower bridge axial tensioning member, the upper and lower joints and the top of the substructure can be tightly connected and rigidly connected without applying unnecessary prestress that would cause constant negative bending stress.

[0027] In particular, according to the inventions of claims 5 and 11, main By connecting the girder support and anchorage block with connecting steel members to form a single unit, the upper and lower joint can be made even more durable. [Brief explanation of the drawing]

[0028] [Figure 1] This is a partially enlarged perspective view showing the rigid connection structure of the upper and lower joint according to the first embodiment of the present invention, obtained by vertically cutting the main girder. [Figure 2] A side view of the same rigid connection structure as shown above, viewed along the direction Y perpendicular to the bridge axis. [Figure 3] Figure 2 is a vertical cross-sectional view taken along line AA. [Figure 4] Figure 2 is a horizontal cross-sectional view taken along the BB line. [Figure 5] This is a perspective view showing only the rigid bridge pier according to this embodiment. [Figure 6] This is a vertical cross-sectional view showing the rigid structure according to the second embodiment, which corresponds to the vertical cross-sectional view of the line AA in Figure 3. [Figure 7] This is a vertical cross-sectional view showing the rigid structure according to the third embodiment, which corresponds to the vertical cross-sectional view of the line AA in Figure 3. [Figure 8] This diagram illustrates the process of erecting the main girder in the rigid structure construction method according to this embodiment. [Figure 9] This is a process diagram illustrating the installation process of the anchoring block for the rigid structure construction method described above. [Modes for carrying out the invention]

[0029] Hereinafter, one embodiment of the rigid joint structure for upper and lower joints and the method for constructing the rigid joint structure for upper and lower joints according to the present invention will be described in detail with reference to the drawings.

[0030] <Rigid connection structure at the upper and lower joints> [First Embodiment] Using Figures 1 to 5, the rigid connection structure 1 (hereinafter also simply referred to as rigid connection structure 1) of the upper and lower joint that rigidly connects the superstructure and substructure of a bridge according to the first embodiment of the present invention will be described. In this embodiment, a T-girder PCaPC girder is used as the main girder 30 of the superstructure 3, and a bridge pier 20 is used as the substructure 2. Figure 1 is a partially enlarged perspective view showing the rigid connection structure 1 of the upper and lower joint according to the embodiment of the present invention, with the main girder 30 cut vertically, and Figure 2 is a side view of the rigid connection structure 1 of the upper and lower joint according to this embodiment, viewed along the direction Y perpendicular to the bridge axis. Furthermore, Figure 3 is a vertical cross-sectional view taken along line AA of Figure 2, and Figure 4 is a horizontal cross-sectional view taken along line BB of Figure 2. In the figures, the X direction is the bridge axis direction X, the Y direction is the direction perpendicular to the bridge axis Y, and the Z direction is the vertical direction.

[0031] As shown in Figures 1 to 4, the bridge B1, which has a rigid connection structure 1 at the upper and lower joint, comprises a substructure consisting of multiple cast-in-place reinforced concrete piers 20 and a superstructure 3 consisting of a main girder 30 erected between these piers 20. The joint between the piers 20 and the main girder 30 is the upper and lower joint 4, and this upper and lower joint 4 is a rigid connection structure 1 that is rigidly connected (rigidly joined) so that the connection angle between the orthogonal main girder 30 and the piers 20 does not deform under stresses within the design strength range.

[0032] (substructure) Substructure 2 consists of cast-in-place reinforced concrete (RC) bridge piers 20. Of course, substructure 2 could also be a bridge abutment, which is not shown in the diagram.

[0033] Figure 5 is a perspective view showing only the pier 20 according to this embodiment. As shown in Figures 5 and 2, the RC pier 20 includes a top portion 21 that rises up to the height of the upper surface of the main girder 30 without the cross-sectional area of ​​the horizontal section decreasing upwards, and main girder supports 22 that protrude from both sides in the bridge axis direction X and on which the main girder 30 is placed.

[0034] As shown in Figure 5, the top portion 21 rises directly from the main body of the pier 20 without changing its depth D1 along the bridge axis direction X or its width W1 along the direction perpendicular to the bridge axis Y. Therefore, the main reinforcement bars arranged along the vertical direction of the pier 20 can be extended and placed all the way to the top portion 21 without bending.

[0035] Furthermore, trapezoidal protrusions 23 are formed on both sides of the top portion 21, which are the ends in the bridge axis direction X, projecting from the sides in the bridge axis direction X. These protrusions 23 work in cooperation with the recesses 33 of the anchoring block 31, which will be described later, to function as bridge axis direction shear keys 5 formed at the joint surface (boundary surface) between the anchoring block 31 and the top portion 21.

[0036] Furthermore, the top portion 21 has two through-holes (not shown) that penetrate in the direction of the bridge axis X for inserting the bridge axis tensioning member 7, which will be described later (see Figure 2, etc.).

[0037] In addition, the main girder support base 22 has connecting steel members 24 that protrude upward from the upper surface of the main girder support base 22. These connecting steel members 24 are embedded in the concrete of the anchoring block 31, and have the function of joining and integrating the anchoring block 31 and the bridge pier 20.

[0038] (superstructure) The superstructure 3 comprises a main girder 30 made of precast reinforced concrete and anchoring blocks 31 made of cast-in-place reinforced concrete. As described later, the anchoring blocks 31 can also be made of precast reinforced concrete.

[0039] As shown in Figures 1 and 3, the main girder 30 is a T-shaped PCaPC girder (precast prestressed concrete girder) with a vertical cross-section that is T-shaped. The main girder 30 has a trapezoidal convex portion 32 formed on the interface surface that contacts the anchoring block 31.

[0040] As shown in Figures 1 to 4, the anchoring block 31 is a rectangular parallelepiped-shaped reinforced concrete block. Furthermore, as shown in Figures 2 to 4, a recess 33 is formed on the joint surface (boundary surface) that contacts the top portion 21, and a recess 34 is formed on the joint surface that contacts the main girder 30, which is shaped to engage with the aforementioned protrusion 32.

[0041] As shown in Figures 2 to 4, the convex portion 23 of the top portion 21 and the concave portion 33 of the anchoring block 31 constitute the axial shear key 5 formed on the joint surface between the anchoring block 31 and the top portion 21. It goes without saying that the convex portion 23 and the concave portion 33 can be reversed in their orientation.

[0042] Furthermore, as shown in Figures 2 to 4, the protrusion 32 projecting from the side surface of the main girder 30 and the recess 34 formed on the side surface of the anchoring block 31 function as a shear key 6 perpendicular to the bridge axis formed at the joint surface (boundary surface) between the anchoring block 31 and the main girder 30. It goes without saying that this function also works even if the protrusions and recesses of the protrusions and recesses of the recess 34 are reversed.

[0043] Furthermore, the anchoring block 31 has a sheath pipe 38 embedded in it, which allows the axial tensioning member 7 and lateral tensioning member 8, described later, to be inserted through it in multiple vertical layers (two layers in the illustrated configuration) (see Figure 9).

[0044] As shown in Figures 1 and 3, infill concrete 35 is poured between the main girders 30 to connect and integrate them.

[0045] (Bridge axial tension member) As shown in Figures 2 to 4, the aforementioned anchoring block 31 and the top portion 21 of the pier 20 are tightly connected by multiple axial tensioning members 7 extending in multiple vertical stages (two stages in the illustrated configuration) along the axial direction X, and are secured with anchoring devices 73 at both ends. In this embodiment, the axial tensioning members 7 are made of PC steel. However, the axial tensioning members according to the present invention are not limited to PC steel, but can be made of other materials such as carbon fiber composite cables that have tensile strength capable of introducing a predetermined prestress.

[0046] Here, as shown in Figure 2, the upper axial tension member 71 is subjected to a predetermined prestress that allows for a rigid connection between the main girder 30 and the pier 20, while the lower axial tension member 72 is not subjected to prestress. This is because it is possible to rigidly connect the anchoring block 31, which is tightly connected to the main girder 30, and the top 21 of the substructure 2, without applying unnecessary prestress that would impose constant negative bending stress. However, in the axial tension member according to the present invention, prestress may be applied to all of the upper and lower multiple stages. Note that "not subjected to prestress" means that a tensioning force is applied to the extent that the anchoring block 31 and the top 21 are tightly fitted together without any gaps, but no tensioning force that would result in more prestress is applied.

[0047] (Transverse tensioning material) Furthermore, the main girder 30 and the anchoring block 31 are tightly connected to prevent displacement by applying prestress with a transverse tensioning member 8 along the direction Y perpendicular to the bridge axis, and are fastened with anchoring devices 83 at both ends. As described above, the anchoring block 31 and the top 21 are tightly connected by applying prestress with a tensioning member 7 in the bridge axis direction, resulting in a rigid connection structure 1 in which the connection angle between the main girder 30 and the bridge pier 20 is rigidly connected (rigidly joined) so that there is no angular deformation.

[0048] As shown in Figure 3, these lateral tensioning members 8 are also provided in multiple layers (two layers in the illustrated configuration), similar to the axial tensioning members 7. However, the upper lateral tensioning members 81 are also subjected to a predetermined prestress necessary to integrate the main girder 30 and the anchorage block 31, and the lower lateral tensioning members 82 are also subjected to the same prestress. This is to ensure that the main girder 30 and the anchorage block 31 are securely integrated without displacement.

[0049] Thus, in the rigid connection structure 1, the upper and lower joints, including both ends of the main girder 30, the anchoring block 31, and the top 21, are rigidly connected by applying prestress in two directions using the axial tensioning member 7 and the transverse tensioning member 8.

[0050] [Second Embodiment] Next, using Figure 6, the rigid connection structure 1' (hereinafter also simply referred to as rigid connection structure 1') of the upper and lower joint according to the second embodiment of the present invention will be described. The main difference from the rigid connection structure 1 according to the first embodiment described above is that, unlike the anchoring block 31 described above, the anchoring block 31' is made of precast reinforced concrete and is integrated with the main girder 30, which is a PCaPC T-girder. Therefore, this point will be explained, and identical components will be denoted by the same reference numerals and their descriptions will be omitted. Figure 7 is a vertical cross-sectional view showing the rigid connection structure 1'' of the third embodiment, which corresponds to the vertical cross-sectional view cut along line AA in Figure 3.

[0051] (superstructure) The superstructure 3' according to the second embodiment comprises the aforementioned precast reinforced concrete main girder 30 and precast reinforced concrete anchoring block 31', which are integrally molded as a PCaPC girder. However, if the weight of the main girder 30 and anchoring block 31' as a single unit exceeds the limit, making transportation and lifting by lifting equipment impossible, the main girder 30 and anchoring block 31' may be assembled on-site as separate precast members, as in the third embodiment described later.

[0052] The anchoring block 31' is a rectangular parallelepiped-shaped reinforced concrete block integrally molded with the main girder 30. As shown in Figure 6, similar to the anchoring block 31, the anchoring block 31' has a recess 33' formed on the joint surface (boundary surface) that contacts the top portion 21, which is shaped to engage with the convex portion 23, and a recess 34' formed on the joint surface that contacts the main girder 30, which is shaped to engage with the convex portion 32.

[0053] As shown in Figure 6, the convex portion 23 of the top portion 21 and the concave portion 33' of the anchoring block 31' constitute a bridge axial shear key formed on the joint surface between the anchoring block 31' and the top portion 21. It goes without saying that the convex portion 23 and the concave portion 33' are still valid even if their orientations are reversed.

[0054] Furthermore, in order to connect adjacent anchoring blocks 31', shear keys perpendicular to the bridge axis are provided on the joint surfaces of the anchoring blocks 31'. As shown in Figure 6, these shear keys perpendicular to the bridge axis consist of a protrusion 36' provided on the side surface of the anchoring block 31' and a recess 37' that engages with this protrusion 36'. Of course, it goes without saying that these protrusions 36' and recesses 37' can also be reversed.

[0055] Furthermore, sheath pipes 38 are embedded in the anchoring block 31' and the main girder 30 in two layers, upper and lower, through which the aforementioned axial tension members 7 and transverse tension members 8 are inserted (see Figure 9). Of course, these sheath pipes 38 are not limited to the illustrated form, and multiple pipes may be provided in accordance with the number of axial tension members 7 and transverse tension members 8.

[0056] [Third Embodiment] Next, the rigid connection structure 1" (hereinafter also simply referred to as rigid connection structure 1") of the upper and lower joint according to the third embodiment of the present invention will be described using Figure 7. The main difference from the rigid connection structure 1' according to the second embodiment described above is that, unlike the anchoring block 31' described above, it is separate from the main girder 30, which is a PCaPC T-girder. Therefore, this point will be explained, and identical components will be denoted by the same reference numerals and their descriptions will be omitted. Figure 7 is a vertical cross-sectional view showing the rigid connection structure 1" of the third embodiment, which corresponds to the vertical cross-sectional view of the AA line in Figure 3.

[0057] (superstructure) The superstructure 3'' according to the third embodiment comprises the aforementioned precast reinforced concrete main girder 30 and a precast reinforced concrete anchoring block 31' which is separate from the main girder 30.

[0058] The anchoring block 31" is a rectangular block made of reinforced concrete. Also, as shown in Figure 7, the anchoring block 31" has a recess 33" formed on the joint surface (boundary surface) that contacts the top portion 21, which is shaped to engage with the aforementioned protrusion 23, and a recess 34" formed on the joint surface that contacts the main girder 30, which is shaped to engage with the aforementioned protrusion 32.

[0059] As shown in Figure 7, the convex portion 23 of the top portion 21 and the concave portion 33" of the anchoring block 31" constitute a bridge axial shear key formed on the joint surface between the anchoring block 31" and the top portion 21. It goes without saying that the convex portion 23 and the concave portion 33" still function even if their orientations are reversed.

[0060] Furthermore, as shown in Figure 7, the protrusion 32 projecting from the side surface of the main girder 30 and the recess 34" formed on the side surface of the anchoring block 31" function as shear keys perpendicular to the bridge axis formed at the joint surface (boundary surface) between the anchoring block 31" and the main girder 30. It goes without saying that this function also works even if the protrusion 32 and recess 34" are reversed.

[0061] Furthermore, similar to the anchoring block 31' in the second embodiment, a shear key perpendicular to the bridge axis is provided on the joint surface of adjacent anchoring blocks 31" in order to connect them. As shown in Figure 7, this shear key perpendicular to the bridge axis consists of a protrusion 36" provided on the side surface of the anchoring block 31" and a recess 37" that engages with this protrusion 36"." Of course, it goes without saying that the connection can be made even if the protrusions and recesses of the protrusions 36" and recess 37" are reversed.

[0062] Furthermore, sheath pipes 38 are embedded in the anchoring block 31" and the main girder 30 in two layers, upper and lower, through which the aforementioned axial tensioning members 7 and transverse tensioning members 8 are inserted (see Figure 9). Of course, these sheath pipes 38" are not limited to the illustrated form, and multiple pipes may be provided in accordance with the number of axial tensioning members 7 and transverse tensioning members 8.

[0063] <Method for constructing a rigid connection structure at the upper and lower joint> Next, a method for constructing a rigid joint structure of the upper and lower joint according to an embodiment of the present invention (hereinafter also simply referred to as the rigid joint structure construction method) will be described using Figures 5, 8, 9, and 2. The explanation will be given using the case of constructing the rigid joint structure 1 according to the first embodiment described above.

[0064] (1. Bridge pier construction process) As shown in Figure 5, first, in the rigid structure construction method according to this embodiment, a pier construction step is performed to construct the pier 20 according to the embodiment of the present invention described above.

[0065] In this pier construction process, unlike conventional piers, the aforementioned top section 21 is constructed so that the cross-sectional area of ​​the horizontal section does not decrease upwards up to the height of the top surface of the main girder 30. In addition, trapezoidal protrusions 23 are constructed on both sides of the top section 21 that are the ends in the bridge axis direction X, projecting from the sides of the top section 21 in the bridge axis direction X. Furthermore, a sheath pipe is installed in the top section 21, through which the aforementioned bridge axis tensioning member 7 is inserted, passing in the bridge axis direction X.

[0066] In this case, the top section 21 rises up without changing its depth D1 and width W1 from the main body of the pier 20. Therefore, the main vertical reinforcement of the main body of the pier 20 can be extended and raised as is. Thus, unlike the upper and lower joints of conventional bridges, the top section 21 does not require bending of the main reinforcement of the pier 20, and does not become a structural weakness.

[0067] Furthermore, unlike the upper and lower joints of conventional bridges, the top section 21 does not require the extension of the main reinforcement of the main girder 30. This simplifies the structure and avoids overcrowded reinforcement, thus not only eliminating structural weaknesses but also simplifying reinforcement placement and shortening construction time.

[0068] In addition, unlike conventional bridge piers, this pier construction process also involves constructing main girder support bases 22 that extend in the bridge axis direction X from both sides of the main body of the pier 20. Furthermore, connecting steel members 24 are provided protruding upward from the upper surface of the main girder support bases 22, forming the anchoring block 31.

[0069] (2. Main girder erection process) Next, as shown in Figure 8, in the rigid structure construction method according to this embodiment, a main girder erection process is performed in which the main girder 30 is erected between a plurality of main girder support bases 22 of the pier 20 constructed in the previous step. Figure 8 is an explanatory diagram of the main girder erection process in the rigid structure construction method according to this embodiment.

[0070] (3. Installation process of fixing blocks) Next, as shown in Figure 9, the rigid structure construction method according to this embodiment involves a fixing block installation step in which the aforementioned fixing block 31 is constructed. Figure 9 is a process explanatory diagram showing the fixing block installation step of the rigid structure construction method according to this embodiment.

[0071] Specifically, formwork is assembled at the location of the aforementioned anchoring block 31 near the end of the main girder 30 erected in the previous step, the predetermined reinforcement is placed inside, and concrete is poured in place. At this time, the formwork for the anchoring block 31 is assembled so as to embed the aforementioned connecting steel members 24, and the formwork is assembled so as to embed the protruding portion 32 of the main girder 30 to construct the recess 34.

[0072] In addition, multiple sheath pipes 38 (not shown) in upper and lower sections through which the axial tensioning member 7 is inserted, and multiple sheath pipes 38 in upper and lower sections through which the lateral tensioning member 8 is inserted are also installed.

[0073] (4. Tightening process) Next, in the rigid connection structure construction method according to this embodiment, the formwork of the anchoring block 31 is removed, and after the poured concrete has reached a predetermined strength, the aforementioned axial tensioning member 7 and lateral tensioning member 8 are inserted into the sheath pipe of the anchoring block 31 and positioned. Then, the tension required for rigid connection is applied to the axial tensioning member 7 and lateral tensioning member 8 and secured with anchoring devices 73 and 83, thereby applying the desired prestress between the main girder 30 and the pier 20 and between the main girder 30 and the anchoring block 31 using a post-tensioning method (see Figure 2).

[0074] However, as mentioned above, the upper axial tension member 71 is subjected to a predetermined prestress that allows for a rigid connection between the main girder 30 and the pier 20, while the lower axial tension member 72 is subjected to only enough tension to ensure that the main girder 30 and the pier 20 are in close contact. This is to avoid applying unnecessary prestress that would create constant negative bending stress.

[0075] Once this fastening process is completed, the rigid structure construction method according to this embodiment is finished, and the rigid structure 1 is completed (see Figures 1 to 4).

[0076] According to the rigid connection structures 1-1" and rigid connection structure construction method according to the embodiment described above, the upper and lower joints of the connecting girders, which conventionally had densely packed reinforcement, do not become densely reinforced. Furthermore, since the joints can be made simply by fastening precast members manufactured off-site, on-site construction can be completed in a short time. Moreover, since there is no dense reinforcement and the concrete can be properly compacted and filled in a factory, which is not affected by weather conditions, unlike conventional reinforcement joints, the area around the top 21, which is the upper and lower joint, does not become a weak point in the quality or structure of the bridge B1, resulting in an extremely high-quality structure.

[0077] Furthermore, according to the rigid connection structure 1-1" and the method for constructing the rigid connection structure, a shear key 5 in the bridge axis direction and a shear key 6 in the direction perpendicular to the bridge axis are provided, thereby improving the shear force resistance of the upper and lower joints near the top 21 and the entire bridge B1.

[0078] Furthermore, according to the rigid connection structure 1-1" and the method for constructing the rigid connection structure, the upper axial tension member 71 is subjected to a predetermined prestress that allows for rigid connection between the main girder 30 and the pier 20, while the lower axial tension member 72 is subjected to only enough tension to ensure that the main girder 30 and the pier 20 are in close contact. This avoids the need to apply unnecessary prestress that would result in constant negative bending stress.

[0079] Although the rigid structures 1-1" and the method for constructing them according to embodiments of the present invention have been described in detail above, the embodiments described above or illustrated are merely examples of specific embodiments implemented in carrying out the present invention. Therefore, the technical scope of the present invention should not be interpreted as being limited by these embodiments. [Explanation of Symbols]

[0080] 1,1',1”: Rigid connection structure (rigid connection structure at the upper and lower joint) 2: Substructure 20: Bridge pier (substructure) 21:Top 22: Main beam support stand 23: Convex section (shear key in the bridge axis direction) 24: Joined steel materials 3:Superstructure 30: Main girder 31,31': Fixing block 32: Convex section (shear key perpendicular to the bridge axis) 33,33': Recess (Shear key in the bridge axis direction) 34,34': Recess (shear key perpendicular to the bridge axis) 35: Infill concrete 36',36": Convex portion (shear key perpendicular to the bridge axis) 37',37”: Recess (shear key perpendicular to the bridge axis) 38: Sheath tube 4: Upper and lower joints 5: Bridge axis shear key 6: Shear key perpendicular to the bridge axis 7: Bridge axial tension material 71: Upper axial tensioning member (axial tensioning member) 72: Lower axial tensioning member (axial tensioning member) 73: Fixing device 8: Transverse tensioning material 81: Upper horizontal tensioning material (horizontal tensioning material) 82: Lower lateral tensioning material (lateral tensioning material) 83: Fixing device

Claims

1. A rigid connection structure for the upper and lower joints that rigidly connect the superstructure and substructure of a bridge, The superstructure comprises a main girder made of precast reinforced concrete and anchoring blocks made of precast reinforced concrete or cast in place. The substructure comprises a top section that rises up to the height of the upper surface of the main girder without the cross-sectional area of ​​the horizontal section decreasing upwards, and a main girder support base that protrudes from the side in the direction of the bridge axis and on which the main girder is placed. The anchoring block and the top portion are fastened together by applying prestress with axial tensioning members along the bridge axis, and the anchoring block and the main girder are fastened together by applying prestress with transverse tensioning members perpendicular to the bridge axis, and the upper and lower joints are rigidly connected by applying prestress in two directions with tensioning members. A rigid connection structure at the upper and lower joints, characterized by the above.

2. The joint surface between the anchoring block and the top portion has a protrusion formed on one side and a recess formed on the other side that fits with this protrusion, thereby forming a shear key in the bridge axial direction. The rigid connection structure of the upper and lower joint according to claim 1, characterized by the above.

3. The joint surface between the anchoring block and the main girder and / or the joint surface between the anchoring blocks themselves has a protrusion formed on one side and a recess formed on the other side that fits with this protrusion, thereby forming a shear key perpendicular to the bridge axis. A rigid connection structure for upper and lower joints according to claim 1 or 2, characterized by the above.

4. The anchoring block and the top portion are provided with multiple axial tension members arranged in the axial direction of the bridge axis, with prestress applied to the upper axial tension members and no prestress applied to the lower axial tension members. A rigid connection structure for upper and lower joints according to any one of claims 1 to 3, characterized by the above.

5. The upper surface of the main girder support is provided with a connecting steel member that protrudes upward. The main girder support and the anchoring block are integrated via the connecting steel material. A rigid connection structure for upper and lower joints according to any one of claims 1 to 4, characterized by the above.

6. A bridge pier comprising a rigid connection structure for the upper and lower joint according to any one of claims 1 to 5, The structure includes a top section that rises up to the height of the upper surface of the main girder without reducing the horizontal cross-sectional area, and a main girder support base that protrudes from the side and on which the main girder is placed. A bridge pier characterized by the following features.

7. A method for constructing a rigid connection structure for an upper and lower joint, which rigidly connects a superstructure having main girders made of precast reinforced concrete of a bridge to a substructure having bridge piers, A bridge pier construction process for constructing multiple bridge piers, each comprising a top portion that rises without decreasing in horizontal cross-sectional area up to the height of the upper surface of the main girder, and a main girder support base that protrudes from the side in the direction of the bridge axis and on which the main girder is placed; A main girder erection process in which the main girder is erected by bridging it between multiple main girder support frames, An anchoring block installation process involves placing a precast reinforced concrete anchoring block on the main girder support or pouring concrete in place into the formwork on the main girder support to construct the anchoring block, The system includes a fastening step of fastening the anchoring block and the top portion by applying prestress with axial tensioning members aligned with the bridge axis, and fastening the anchoring block and the main girder by applying prestress with transverse tensioning members aligned perpendicular to the bridge axis. A method for constructing a rigid connection structure at the upper and lower joint, characterized by the above.

8. In the fastening process, a protrusion is formed on one of the joint surfaces between the anchoring block and the top portion, and a recess that fits with this protrusion is formed on the other to form a bridge axial shear key for fastening. A method for constructing a rigid connection structure for upper and lower joints according to claim 7, characterized by the above.

9. In the fastening process, a protrusion is formed on one of the joint surfaces of the anchoring block and the main girder, and a recess that fits with this protrusion is formed on the other, and a shear key perpendicular to the bridge axis is formed to fasten them together. A method for constructing a rigid connection structure for upper and lower joints according to claim 7 or 8, characterized by the above.

10. In the fastening process, the anchoring block and the top portion are fastened together with multiple upper and lower axial tension members along the bridge axis direction, with prestress applied to the upper axial tension members and no prestress applied to the lower axial tension members. A method for constructing a rigid connection structure for an upper and lower joint according to any one of claims 7 to 9, characterized by the above.

11. A connecting steel member that protrudes upward is provided on the upper surface of the main girder support, In the anchoring block installation process, the main girder support and the anchoring block are connected and integrated using the connecting steel material. A method for constructing a rigid connection structure for an upper and lower joint according to any one of claims 7 to 10, characterized by the above.

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