A low pier continuous rigid frame bridge

Abstract

The present invention relates to the technical field of bridge engineering, and in particular to a low pier continuous rigid frame bridge, comprising a pier body and a box beam; the pier body is composed of a pier body and special-shaped steel, the pier body is a solid pier body, the special-shaped steel is an "I" shape, the special-shaped steel is arranged inside the pier body, the material of the pier body is UHPC, the inside of the pier body has pier body longitudinal reinforcement and pier body stirrups surrounding the special-shaped steel and tied to each other, and the pier body longitudinal reinforcement is connected to the special-shaped steel; at least one shear key is vertically arranged on the upper end surface of the special-shaped steel, and the shear key has a plurality of openings; the box beam is connected to the upper end of the pier body, the inside of the box beam has box beam longitudinal reinforcement and box beam stirrups tied to each other, one end of the shear key is connected to the upper end surface of the special-shaped steel, and the other end extends into the box beam, and the plurality of openings are all penetrated with box beam stirrups. The low pier of the continuous rigid frame bridge provided by the present invention has high flexibility of the low pier and low anti-thrust stiffness.

Description

Technical Field

[0001] The invention relates to the technical field of bridge engineering, and in particular to a short pier continuous rigid frame bridge. Background Art

[0002] Prestressed concrete continuous box girder bridges have been widely used in bridge engineering in my country. However, in recent years, due to overloading and other reasons, some continuous box girder bridges have experienced rollover accidents, resulting in serious casualties. The reason is that in addition to the serious overloading and eccentric driving of the vehicles, the upper structure of the continuous box girder bridge and the lower structure of the bridge are only connected by bearings. Under extreme loads, there is no effective constraint, which is prone to translation and rotation, which is one of the main reasons for the rollover of the box girder.

[0003] If the support is eliminated and the box girder and the pier are directly consolidated to form a continuous rigid frame system, the rollover resistance of the box girder can undoubtedly be significantly improved. However, this structural system is generally only suitable for taller and softer concrete piers. For concrete beam bridges with short piers, if a continuous rigid frame system is used, the short piers have large anti-thrust stiffness and poor horizontal deformation capacity, making it unable to adapt to the horizontal deformation of the box girder caused by temperature changes. Summary of the invention

[0004] In order to overcome the defects of the prior art mentioned above, the technical problem to be solved by the present invention is to provide a continuous rigid frame bridge with high flexibility of the short pier and low anti-thrust stiffness.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A low pier continuous rigid frame bridge comprises a pier body and a box girder;

[0007] The pier body is composed of a pier body and special-shaped steel, the pier body is a solid pier body, the special-shaped steel is in an "I" shape, the special-shaped steel is arranged inside the pier body, the material of the pier body is UHPC, and the inside of the pier body has pier body longitudinal reinforcement and pier body stirrups surrounding the special-shaped steel and tied to each other, and the pier body longitudinal reinforcement is connected to the special-shaped steel;

[0008] At least one shear key is vertically arranged on the upper end surface of the special-shaped steel, and the shear key has a plurality of openings;

[0009] The box girder is connected to the upper end of the pier body, and the interior of the box girder has box girder longitudinal reinforcement and box girder stirrups that are bound together. One end of the shear key is connected to the upper end surface of the special-shaped steel, and the other end extends into the box girder, and box girder stirrups are inserted into the plurality of openings.

[0010] Wherein, the special-shaped steel includes a main steel plate, an end plate and a plurality of wing plates;

[0011] End plates are provided at both ends of the main steel plate in the length direction, and the shear keys are provided on the end plates;

[0012] The plurality of wing plates are sequentially arranged in the length direction of the main steel plate;

[0013] The end plate and the wing plate are both provided with reserved through holes;

[0014] Each of the reserved through holes is penetrated with pier body longitudinal reinforcement.

[0015] There are multiple shear keys, which are arranged in parallel with each other, and box girder longitudinal reinforcements are inserted into gaps between adjacent shear keys.

[0016] Wherein, stiffening ribs are arranged on the upper end surface and the lower end surface of the special-shaped steel.

[0017] Among them, it also includes a prefabricated foundation, which is provided with a groove, and a plurality of pre-embedded corrugated pipes are arranged on the bottom surface of the groove. The pier body is vertically arranged in the groove, and the lower end of the pier body longitudinal reinforcement protrudes from the lower end surface of the pier body and extends into the inner cavity of the pre-embedded corrugated pipe.

[0018] Wherein, UHPC is filled between the groove and the pier body.

[0019] The beneficial effects of the present invention are:

[0020] (1) By using special-shaped steel as the embedded steel frame of the pier body to reinforce the short pier, the vertical compression deformation of the short pier can be effectively reduced, the vertical compressive strength of the short pier can be improved, and the large secondary internal force of the box girder caused by the large vertical deformation of the short pier can be effectively avoided;

[0021] (2) Compared with traditional reinforced concrete bridge piers, the short pier provided by the present invention has higher vertical compressive strength, and thus can significantly reduce the cross-sectional size and anti-thrust stiffness of the short pier, while also improving the flexibility of the short pier, so that it can adapt to the horizontal deformation of the box girder caused by temperature changes, thereby making the structure of the short pier continuous rigid frame bridge a structural system with reasonable stress;

[0022] (3) By adopting the pier-beam consolidation system, that is, connecting the box girder longitudinal reinforcement and box girder stirrups through shear keys, the translation and rotation of the box girder can be effectively restrained to avoid the occurrence of sudden box girder rollover accidents;

[0023] (4) Since the low pier continuous rigid frame bridge provided by the present invention uses less concrete and each structural member is relatively light in weight, the rigid frame bridge can be constructed using a centralized prefabrication, hoisting transportation and assembly construction mode, which can effectively improve the construction efficiency of the rigid frame bridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of a short pier continuous rigid frame bridge at an angle in a specific implementation manner of the present invention;

[0025] Figure 2 Shown Figure 1 AA section view in;

[0026] Figure 3 Shown Figure 1 A magnified view of part B in FIG.

[0027] Figure 4 It is a schematic structural diagram of a short pier continuous rigid frame bridge in a specific embodiment of the present invention at another angle;

[0028] Figure 5 Shown Figure 4 Middle CC section.

[0029] Explanation of numbers: 1. Pier body; 11. Pier body; 12. Pier body longitudinal reinforcement; 13. Pier body stirrups; 14. Special-shaped steel; 141. Stiffening ribs; 142. Shear keys; 143. Upper end plate; 144. Wing plate; 145. Main steel plate; 2. Precast cap; 21. Groove; 22. Embedded corrugated pipe; 3. Box girder; 31. Box girder stirrups; 32. Box girder longitudinal reinforcement. DETAILED DESCRIPTION

[0030] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings.

[0031] The most critical concept of the present invention is: by using special-shaped steel as the steel frame of the pier body to reinforce the short pier to improve the vertical compressive strength of the short pier, the cross-sectional size of the short pier and the anti-thrust stiffness of the short pier can be significantly reduced, and the flexibility of the short pier can be improved, so that the short pier can adapt to the horizontal deformation of the box girder caused by temperature changes.

[0032] It should be noted that, in this article, the "UHPC" refers to ultra-high performance concrete.

[0033] The present invention discloses a low pier continuous rigid frame bridge, comprising a pier body 1 and a box beam 3; the pier body 1 is composed of a pier body 11 and a special-shaped steel 14, wherein the pier body 11 is a solid pier body, the special-shaped steel 14 is an "I" shape, the special-shaped steel 14 is arranged inside the pier body 11, the material of the pier body 11 is UHPC, and the inside of the pier body 11 has pier body longitudinal reinforcement 12 and pier body stirrups 13 surrounding the special-shaped steel 14 and tied to each other, the pier body longitudinal reinforcement 12 It is connected to the special-shaped steel 14; at least one shear key 142 is vertically arranged on the upper end surface of the special-shaped steel 14, and the shear key 142 has a plurality of openings; the box girder 3 is connected to the upper end of the pier body 1, and the interior of the box girder 3 has box girder longitudinal reinforcement 32 and box girder stirrups 31 that are bound to each other, one end of the shear key 142 is connected to the upper end surface of the special-shaped steel 14, and the other end extends into the box girder 3, and the plurality of openings are penetrated by box girder stirrups 31.

[0034] For details, see Figures 1 to 4 The special-shaped steel 14 is in an “I” shape, and at least one shear key 142 is vertically arranged on the upper end surface of the special-shaped steel 14 . The special-shaped steel 14 is connected to the longitudinal reinforcement 12 of the pier body.

[0035] The pier shaft longitudinal reinforcement 12 is sleeved or welded with the special-shaped steel 14. Preferably, the shear key 142 is welded to the end plate at the upper end. In one embodiment, the opening on the shear key 142 is used to connect with a crane to achieve the transfer of the pier shaft 1 and the special-shaped steel 14.

[0036] Preferably, the shear key 142 is a PBL shear key 142 .

[0037] See also Figure 1 , Figure 2 and Figure 4 The pier body 1 is composed of a pier body 11 and a special-shaped steel 14. The pier body 11 is a solid pier body, and the material of the pier body 11 is UHPC. The pier body 11 has pier body longitudinal reinforcement 12 and pier body stirrups 13 surrounding the special-shaped steel 14 and tied to each other.

[0038] The pier body 1 is prefabricated, and the pier body 1 is provided with mutually tied pier body longitudinal reinforcements 12 and pier body stirrups 13 inside to improve the structural strength of the pier body 1. In one embodiment, the special-shaped steel 14 is first fixed in the mold, and then the construction workers tie the pier body longitudinal reinforcements 12 and pier body stirrups 13 around the special-shaped steel 14 and connect the special-shaped steel 14 with the pier body longitudinal reinforcement 12, and finally pour UHPC into the mold to embed the special-shaped steel 14 in the pier body 11, thereby completing the prefabrication of the pier body 1.

[0039] It should be noted that the horizontal cross-sectional profile of the pier body 1 includes, but is not limited to, circular, elliptical, and rectangular.

[0040] See also Figure 1 , Figure 4 and Figure 5 The box girder 3 is connected to the upper end of the pier body 1, and the interior of the box girder 3 has box girder longitudinal reinforcement 32 and box girder stirrups 31 that are bound together. One end of the shear key 142 is connected to the upper end surface of the special-shaped steel 14, and the other end extends into the box girder 3, and a plurality of the openings are penetrated with box girder stirrups 31.

[0041] In one embodiment, when the bridge substructure is connected and fixed to the bridge superstructure, that is, when the pier body 1 and the special-shaped steel 14 are connected and fixed to the box girder 3, the shear key 142 arranged on the upper end surface of the special-shaped steel 14 is completely inserted into the interior of the box girder 3, and part of the box girder stirrups 31 pass through the openings of the shear key 142.

[0042] Preferably, in one embodiment, the box girder 3 is cast-in-place, that is, after the box girder 3 is connected to the pier body 1 , the construction workers cast the box girder 3 in-place using a mold of the box girder 3 .

[0043] From the above description, it can be seen that the beneficial effects of the invention are: by using the special-shaped steel 14 as the steel frame of the pier body 1 to reinforce the short pier, the vertical compression deformation of the short pier can be effectively reduced, the vertical compressive strength of the short pier can be improved, and the large secondary internal force of the box girder 3 caused by the large vertical deformation of the short pier can be effectively avoided; compared with traditional reinforced concrete piers, the short pier provided by the present invention has a higher vertical compressive strength, and therefore can significantly reduce the cross-sectional size of the short pier and the anti-thrust stiffness of the short pier, and at the same time also improves the flexibility of the short pier, so that it can adapt to the box girder 3 produced by temperature changes. The horizontal deformation is reduced, so that the structure of the short pier continuous rigid frame bridge becomes a structural system with reasonable stress; by adopting the pier-beam consolidation system, that is, connecting the box girder longitudinal reinforcement 32 and the box girder stirrups 31 of the box girder 3 through the shear key 142, the translation and rotation of the box girder 3 can be effectively constrained to avoid the occurrence of sudden rollover accidents of the box girder 3; because the short pier continuous rigid frame bridge provided by the present invention uses less concrete and the weight of each structural component is relatively light, the rigid frame bridge can be constructed by a construction mode of centralized prefabrication, hoisting transportation and assembly, which can effectively improve the construction efficiency of the rigid frame bridge.

[0044] For further information, see Figures 1 to 4 The special-shaped steel 14 includes a main steel plate 145, an end plate and a plurality of wing plates 144; end plates are provided at both ends of the length direction of the main steel plate 145, and the shear keys 142 are provided on the end plates; a plurality of wing plates 144 are sequentially provided in the length direction of the main steel plate 145; reserved through holes are provided on the end plates and the wing plates 144; each of the reserved through holes is penetrated with a pier shaft longitudinal reinforcement 12.

[0045] The special-shaped steel 14 is constructed with a main steel plate 145 as the main skeleton, and end plates are welded at both ends of the length direction, and a plurality of wing plates 144 are welded horizontally in sequence in the length direction. Preferably, the reserved through holes provided on the wing plates 144 and the end plates are relatively aligned, that is, the corresponding reserved through holes are coaxially arranged. Specifically, in one embodiment, the pier body 1 is prefabricated by a flat casting method, that is, the prefabricated special-shaped steel 14 is first fixed in the formwork, and then the pier body stirrups 13 and the pier body longitudinal reinforcement 12 are tied around the special-shaped steel 14, wherein each of the reserved through holes is penetrated with the pier body longitudinal reinforcement 12 to achieve the connection between the special-shaped steel 14 and the pier body longitudinal reinforcement 12, and finally UHPC is poured into the formwork to complete the prefabrication of the pier body 1.

[0046] Preferably, both axial ends of the pier shaft longitudinal reinforcement 12 protrude from the pier shaft 1 , that is, both axial ends of the pier shaft longitudinal reinforcement 12 protrude from the upper end plate 143 and the lower end plate respectively and extend along the axial direction thereof.

[0047] From the above description, it can be seen that by arranging a plurality of wing plates 144 in the length direction of the main steel plate 145 and passing the pier body longitudinal reinforcement 12 through the reserved through holes on the special-shaped steel 14, the structural strength of the pier body 1 is improved, and the density of the pier body 1 is improved.

[0048] Optionally, both the wing plate 144 and the end plate are PBL shear keys 142 .

[0049] For further information, see Figure 3 The shear keys 142 are arranged in plurality, the plurality of shear keys 142 are arranged parallel to each other, and the box girder longitudinal reinforcement 32 is passed through the gaps between adjacent shear keys 142 .

[0050] From the above description, it can be seen that by providing a plurality of shear keys 142, wherein the gaps between adjacent shear keys 142 are penetrated with box girder longitudinal reinforcements 32, this connection method can further strengthen the connection strength between the bridge superstructure and the bridge substructure.

[0051] For further information, see Figure 1 , Figure 3 and Figure 4 The upper and lower end surfaces of the special-shaped steel 14 are both provided with stiffening ribs 141 .

[0052] From the above description, it can be seen that in order to improve the stability and torsional resistance of the low pier continuous rigid frame bridge, preferably, stiffening ribs 141 are provided on the upper and lower end surfaces of the special-shaped steel 14. The stiffening ribs 141 are provided in plurality, and the specific number should be set according to actual engineering requirements.

[0053] For further information, see Figure 1 and Figure 4 , and also includes a prefabricated foundation 2, which is provided with a groove 21, and a plurality of pre-embedded corrugated pipes 22 are provided on the bottom surface of the groove 21. The pier body 1 is vertically arranged in the groove 21, and the lower end of the pier body longitudinal reinforcement 12 protrudes from the lower end surface of the pier body 11 and extends into the inner cavity of the pre-embedded corrugated pipe 22.

[0054] Furthermore, UHPC is filled between the groove 21 and the pier body 1 .

[0055] From the above description, it can be seen that the embedded corrugated pipe 22 is embedded in the bottom surface of the groove 21; in one embodiment, UHPC is pre-filled into the groove 21 and the embedded corrugated pipe 22, and then the pier body 1 and the special-shaped steel 14 are lifted to the top of the prefabricated foundation 2 by a crane, and slowly lowered so that the lower end of each pier body longitudinal reinforcement 12 is inserted into the embedded corrugated pipe 22. At this time, the space between the embedded corrugated pipe 22 and the pier body longitudinal reinforcement 12 and between the pier body 1 and the side wall of the groove 21 are filled with ultra-high performance mortar. Through this installation method, the connection strength between the prefabricated foundation 2 and the pier body 1 is improved, thereby improving the stability of the short pier continuous rigid frame bridge.

[0056] Preferably, in one embodiment, after the pier body 1 and the groove 21 are seated, soil is filled on the surface of the groove 21. Preferably, the soil is filled so that the ground line where the foundation is located is slightly higher than the groove 21. Through this operation process, the connection strength between the prefabricated foundation 2 and the pier body 1 is ensured.

[0057] Embodiment 1

[0058] In the first step, the construction workers first make the pier body 1, and the prefabricated special-shaped steel 14 is pre-set in the formwork. Then, the pier body longitudinal reinforcement 12 and the pier body stirrups 13 are tied around the special-shaped steel 14, and each reserved through hole on the end plate and the wing plate 144 is penetrated with the pier body longitudinal reinforcement 12, and then UHPC is poured into the formwork to obtain the prefabricated pier body 1. Among them, the axial ends of the pier body longitudinal reinforcement 12 protrude from the upper end plate 143 and the lower end plate of the special-shaped steel 14 respectively, and four PBL shear keys 142 are arranged on the upper end plate 143, which are parallel to each other and perpendicular to the upper end plate 143, and the openings on each PBL shear key 142 are arranged to be aligned with each other;

[0059] In the second step, the construction workers cast the prefabricated cap 2. A groove 21 for supporting the pier body 1 is arranged on the upper end surface of the prefabricated cap 2, and a plurality of pre-buried grouting corrugated pipes are arranged on the bottom of the groove 21.

[0060] In the third step, the construction workers first pour UHPM (ultra-high performance mortar) into the groove 21 of the pre-buried grouting corrugated pipe and the prefabricated cap 2, and then connect the PBL shear key 142 to the crane to lift the pier body 1, and insert the exposed pier body longitudinal reinforcement 12 into the pre-buried grouting corrugated pipe. The pier body 1 is placed in the groove 21 of the prefabricated cap 2, and finally the mortar is seated to complete the connection between the pier body 1 and the prefabricated cap 2;

[0061] In the fourth step, the construction personnel fill the groove 21 of the prefabricated cap 2 so that the ground line slightly covers the groove 21 on the top surface of the cap;

[0062] In the fifth step, the construction workers insert the special-shaped steel 14 of the pier body 1 and the pier body longitudinal reinforcement 12 located at the upper end of the pier body 1 into a small section at the bottom of the box girder 3, and tie the pier body longitudinal reinforcement 12, the box girder longitudinal reinforcement 32 and the box girder stirrups 31 together, and make the box girder stirrups 31 pass through the openings on the PBL shear keys 142, and make the box girder longitudinal reinforcement 32 pass through the gaps between the PBL shear keys 142;

[0063] The sixth step is to cast the box girder 3 in situ. After the casting of the box girder 3 is completed, the construction of the whole bridge is completed.

[0064] In summary, the present invention provides a low pier continuous rigid frame bridge, which can effectively reduce the vertical compression deformation of the low pier and improve the vertical compressive strength of the low pier by using special-shaped steel 14 as the steel frame of the pier body 1 to reinforce the low pier, and can effectively avoid the large secondary internal force of the box girder 3 caused by the large vertical deformation of the low pier; compared with the traditional reinforced concrete piers, the low pier provided by the present invention has higher vertical compressive strength by selecting UHPC as the pier body 1 concrete of the pier body 1, and therefore can significantly reduce the cross-sectional size of the low pier and the anti-thrust stiffness of the low pier, and at the same time also improve the flexibility of the low pier, so that it can adapt to the box girder 3. The horizontal deformation caused by temperature changes makes the structure of the short pier continuous rigid frame bridge a structural system with reasonable force; by adopting the pier-beam consolidation system, that is, connecting the box girder longitudinal reinforcement 32 and the box girder stirrups 31 of the box girder 3 through the shear key 142, the translation and rotation of the box girder 3 can be effectively constrained to avoid the occurrence of sudden rollover accidents of the box girder 3; since the short pier continuous rigid frame bridge provided by the present invention uses less concrete and the weight of each structural component is relatively light, the rigid frame bridge can be constructed in a centralized prefabrication, hoisting transportation and assembly construction mode, which can effectively improve the construction efficiency of the rigid frame bridge; the pier body 1 has a smaller cross-sectional area than the ordinary pier body 1, which can effectively increase the driving sight distance and has high construction efficiency, and can be suitable for urban bridge construction.

[0065] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A low pier continuous rigid frame bridge, characterized in that: Including pier and box girder; The pier body is composed of a pier body and special-shaped steel, the pier body is a solid pier body, the special-shaped steel is in an "I" shape, the special-shaped steel is arranged inside the pier body, the material of the pier body is UHPC, the inside of the pier body has pier body longitudinal reinforcement and pier body stirrups surrounding the special-shaped steel and tied to each other, and the pier body longitudinal reinforcement is connected to the special-shaped steel; At least one shear key is vertically arranged on the upper end surface of the special-shaped steel, and the shear key has a plurality of openings; The box girder is connected to the upper end of the pier body, and the box girder has box girder longitudinal bars and box girder stirrups tied to each other inside. One end of the shear key is connected to the upper end surface of the special-shaped steel, and the other end extends into the box girder. Box girder stirrups are inserted into the plurality of openings. The special-shaped steel includes a main steel plate, an end plate and a plurality of wing plates; End plates are provided at both ends of the main steel plate in the length direction, and the shear keys are provided on the end plates; The plurality of wing plates are sequentially arranged in the length direction of the main steel plate; The end plate and the wing plate are both provided with reserved through holes; Each of the reserved through holes is penetrated with longitudinal reinforcement of the pier body; The shear keys are arranged in plurality, the plurality of shear keys are arranged parallel to each other, and the gaps between adjacent shear keys are penetrated by box girder longitudinal reinforcements; Stiffening ribs are arranged on the upper end surface and the lower end surface of the special-shaped steel.

2. The low pier continuous rigid frame bridge according to claim 1, characterized in that: It also includes a prefabricated foundation, which is provided with a groove, and a plurality of pre-buried corrugated pipes are provided on the bottom surface of the groove. The pier body is vertically arranged in the groove, and the lower end of the pier body longitudinal reinforcement protrudes from the lower end surface of the pier body and extends into the inner cavity of the pre-buried corrugated pipe.

3. The low pier continuous rigid frame bridge according to claim 2, characterized in that: The groove and the pier body are filled with UHPC.

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