Construction method for lengthening and transforming bridge body

Abstract

The invention discloses a construction method for lengthening and transforming a bridge body, and belongs to the technical field of civil construction. The construction method for lengthening and transforming the bridge body is used for lengthening and transforming a main beam between an original bridge pier and an original bridge abutment, and comprises the following steps: chiseling off part of concrete protection layers on a top plate and a bottom plate, close to the end part of a newly-added bridge pier, of the main beam until main reinforcements on the top plate and the bottom plate are exposed; and the longitudinal main reinforcements in the length direction of the main beam are reserved, the longitudinal main reinforcements are lengthened, the prestressed steel strands are arranged, concrete is poured, and the beam body lengthening work is completed. According to the construction method for lengthening and transforming the bridge body, the span of an existing bridge is increased, the extension requirement of an underneath pass road is met, compared with dismantling and reconstruction, the construction period is short, cost can be saved, resource waste is reduced, and great social benefits are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction, and in particular to a construction method for lengthening and modifying a bridge beam. Background Art

[0002] During the long-term use of some old viaducts, the highways under them need to be widened and renovated due to the increase in traffic volume and the adjustment of line planning. At this time, since the main beam span of the existing viaduct cannot meet the widening requirements of the highway under it, the existing bridge needs to be renovated to meet the new use requirements. The construction of the beam reconstruction involves key technical issues such as the conversion of the structural force system and the connection between the old and new structures. The construction quality directly affects the overall performance and service life of the bridge.

[0003] Traditional methods of beam reconstruction mostly involve dismantling and rebuilding the viaduct above the original highway, increasing the span of the main beam of the new bridge to meet the needs of expanding the underpass. However, this construction method has a long construction period, high construction costs, and leads to waste of resources, resulting in low social benefits. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems in the prior art and provide a construction method for extending and modifying a bridge beam, so as to increase the span of the bridge while meeting the structural force requirements and relevant regulatory requirements. After increasing the beam span, the needs for reconstruction and expansion of the underpass can be met, and costs can be saved, resource waste can be reduced, and great social benefits can be achieved.

[0005] The present invention provides a construction method for lengthening and reconstructing a bridge beam, which is used for lengthening and reconstructing a main beam between an original bridge pier and an original bridge abutment. The construction method comprises the following steps:

[0006] Set up temporary steel pipe supports on the ground, use them to support the main beam, and then remove the original abutment;

[0007] Add a new pier on the side of the original abutment away from the original pier, set up a full-bridge support on the ground, and use the full-bridge support to extend the main beam;

[0008] Chisel away part of the concrete protective layer on the top and bottom plates of the main beam near the end of the newly added pier until the main reinforcement on the top and bottom plates is exposed, retain the longitudinal main reinforcement along the length of the main beam, extend the main beam using the extended beam body, connect the longitudinal main reinforcement of the main beam with the main reinforcement of the extended beam body, and connect the extended beam body to the original aqueduct through the transition beam body;

[0009] Concrete is poured on the main reinforcement of the main beam and the extended beam. After the concrete reaches the predetermined strength, multiple steel strands are installed on the main beam and the extended beam, and the steel strands are kept in a tensioned state. The main beam and the extended beam form a new beam span, and the new beam span is supported by the newly added piers to increase the span of the main beam.

[0010] After the new beam span reaches the predetermined strength, the temporary supports and full-span brackets are removed, and the new beam span is paved.

[0011] Preferably, when the main beam is extended by using the extended beam body, the concrete on the web and bottom plate of the main beam is roughened, and multiple steel plates are fixed to the bottom plate and web of the main beam by gluing and anchoring, and anchor nails are welded on each steel plate, and the anchor nails are welded to the main reinforcement on the extended beam body, so that the multiple steel plates are interconnected into a U-shaped structure, and the bottom plate and web of the main beam and the lower part of the extended beam body are surrounded by the multiple steel plates.

[0012] Preferably, when the main beam is extended by using the extended beam body, the webs on the left and right sides of the main beam cross section are thickened, and a plurality of full-length prestressed tendons along the length direction of the main beam are arranged on the webs on both sides of the main beam and the webs at corresponding positions on both sides of the extended beam body. Then, while pouring concrete on the main beam and the main reinforcement of the extended beam body, concrete is poured on the webs and the plurality of full-length prestressed tendons.

[0013] Preferably, when the main beam is extended by using an extended beam body, the portion of the bottom plate of the main beam located above the original abutment is thickened, and the end face of the thickened main beam is extended with the extended beam body so that the upper end face of the main beam is flush with the upper end face of the extended beam body.

[0014] Preferably, when the main beam is extended by using the extended beam body, a plurality of corrugated tubes are arranged on the main reinforcement of the main beam along the length direction of the main beam, each corrugated tube is distributed on the bottom plate and the web of the main beam, and each corrugated tube is located outside the original main beam contour, so that after the main reinforcement of the main beam and the extended beam body is poured with concrete, the web and bottom plate of the main beam can be thickened while each corrugated tube can be fixed.

[0015] Preferably, when multiple steel strands are arranged on the main beam and the extended beam, the multiple steel strands are arranged on the web and bottom plate of the main beam and the web and bottom plate of the extended beam at corresponding positions, and the steel strands are passed through the corrugated tube on the main beam and the web corrugated tube at corresponding positions on the extended beam, and then the steel strands are tensioned to ensure that the structural force on the extended beam and the main beam meets the requirements.

[0016] Preferably, when the main beam is extended by using the extended section beam body, a new abutment is set up on the side of the new pier away from the pier, and the new abutment is used to support the transition section beam body.

[0017] Preferably, when paving the new beam span, the new beam span is constructed with the bridge deck paving, anti-throwing net base, anti-throwing net and expansion joint according to the original aqueduct structure type and size.

[0018] Preferably, when paving a new beam span, polymer mortar or polymer putty is used to repair defects on the concrete surface of the new beam span.

[0019] Preferably, after paving the new beam span, the concrete surface on the new beam span is subjected to anti-corrosion coating to improve the durability of the concrete.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The construction method for extending and reconstructing the bridge beam body is to chisel off part of the concrete protective layer on the top plate and the bottom plate of the main beam near one end of the newly added pier, and then use the extended beam body to extend the main beam, connect the longitudinal main reinforcement of the main beam with the main reinforcement of the extended beam body, and connect the extended beam body with the original aqueduct through the transition beam body; finally, pour concrete on the main reinforcement of the main beam and the extended beam body to increase the span of the main beam. This method is suitable for the main beam of the bridge, such as the extended beam bridge and the T-beam bridge. Compared with the traditional demolition and new construction method, this construction method can increase the span of the bridge while meeting the structural force requirements and the requirements of the bridge construction specifications. It not only increases the span of the existing bridge to meet the needs of the reconstruction and expansion of the underpass, but also meets the structural force and specification requirements, and can save costs and reduce resource waste, with great social benefits.

[0022] The construction method of the bridge beam extension and reconstruction can strengthen the structural integrity of the main beam and the extended section beam. By roughening the concrete within a certain range of the web and bottom plate on the main beam and increasing the cross section, the concrete cross section required for the steel strand formation can be increased to increase the strength of the new beam after the beam is extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the main beam;

[0024] Figure 2 for Figure 1 Schematic diagram of the cross section at AA in the middle;

[0025] Figure 3 for Figure 1 Schematic diagram of the cross section at the middle BB;

[0026] Figure 4 for Figure 1 Schematic diagram of the steel strand arrangement elevation;

[0027] Figure 5 for Figure 1Schematic diagram of the steel strand arrangement plan;

[0028] Figure 6 for Figure 4 Schematic diagram of the cross section at CC;

[0029] Figure 7 for Figure 4 Schematic diagram of the cross section at DD;

[0030] Figure 8 for Figure 4 Schematic diagram of the cross section at EE.

[0031] Description of reference numerals:

[0032] 1. Transition section beam; 2. Main beam; 3. Extended section beam; 4. Bridge piers; 5. Original abutments; 6. Newly added bridge piers; 7. Steel plates; 8. Corrugated pipes; 9. Steel strands; 10. Ground; 11. Temporary steel pipe supports; 12. Newly added abutments; 13. Original aqueduct. DETAILED DESCRIPTION

[0033] To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the following will be combined with the appended drawings of the embodiments of the present invention. Figure 1-Figure 8 , the technical scheme of the embodiment of the present invention is clearly and completely described. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Unless otherwise defined, the technical or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. "Include" or "comprises" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Inside", "outside", "upper", "lower", "far", "near", "front", "back", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0035] The appended Figure 1-Figure 8 The drawings are not drawn strictly according to the actual scale, and the specific size and quantity of each structure can be determined according to actual needs. The drawings described in the present invention are only schematic diagrams of the structures.

[0036] like Figure 1-Figure 8 The construction method for extending and reconstructing a bridge beam provided by the present invention is used to extend and reconstruct the main beam 2 between the original pier 4 and the original abutment 5. The construction method comprises the following steps:

[0037] A temporary steel pipe support 11 is set up on the ground 10, and after the main beam 2 is supported by the temporary steel pipe support 11, the original abutment 5 is removed;

[0038] A new bridge pier 6 is added on the side of the original bridge abutment 5 away from the original bridge pier 4, and a full-bridge support is set up on the ground 10, and the main beam 2 is extended by the full-bridge support;

[0039] Chisel away part of the concrete protective layer on the top plate and the bottom plate of the main beam 2 near one end of the newly added pier 6 until the main reinforcement on the top plate and the bottom plate is exposed, retain the longitudinal main reinforcement along the length direction of the main beam 2, extend the main beam 2 by using the extended beam body 3, connect the longitudinal main reinforcement of the main beam 2 with the main reinforcement of the extended beam body 3, and connect the extended beam body 3 with the original aqueduct 13 through the transition beam body 1;

[0040] Concrete is poured on the main reinforcement of the main beam 2 and the extended beam body 3. After the concrete reaches a predetermined strength, a plurality of steel strands 9 are arranged on the main beam 2 and the extended beam body 3, and the steel strands 9 are kept in a tensioned state. The main beam 2 and the extended beam body 3 form a new beam span, and the new beam span is supported by the newly added piers 6, so as to increase the span of the main beam 2;

[0041] After the new beam span reaches the predetermined strength, the temporary support 21 and the full-span support are removed, and the new beam span is paved.

[0042] The working principle of the above embodiment is briefly described:

[0043] The extended section beam body 3 used in this method is a box beam, the diameter of the newly added pier 6 is 1.3m, the pile length is 44m, the size of the extended section beam body 3 is 6m long × 1.7m wide × 1.5~2.2m high, and the concrete protective layer of 30cm on the top and bottom plates of the main beam 2 along the length direction of the main beam 2 is chiseled off. The material of the steel plate is Q345NH, the steel plate 7 is 10mm thick and 4m long, the 2m length of the steel plate 7 corresponds to the connection on the main beam 2, and the other 2m length corresponds to the connection on the extended section beam body 3.

[0044] The construction method of lengthening and transforming the bridge beam is applicable to the main beam 2 of the bridge, such as the extended beam 3 bridge and the T-beam bridge. Compared with demolition and new construction, this patent can increase the span of the bridge while meeting the structural force requirements and relevant regulatory requirements. It not only increases the span of the existing bridge to meet the needs of the reconstruction and expansion of the underpass, but also meets the structural force and regulatory requirements, and can save costs, reduce resource waste, and has great social benefits.

[0045] As a preferred method, Figure 1-Figure 3As shown, when the main beam 2 is extended by using the extended beam body 3, the concrete on the web and bottom plate of the main beam 2 is roughened, and a plurality of steel plates 7 are fixed on the bottom plate and web of the main beam 2 by using a gluing process and anchor bolts, and anchor nails are welded on each steel plate 7, and the anchor nails are welded to the main reinforcement on the extended beam body 3, so that the plurality of steel plates 7 are interconnected into a U-shaped structure, and the bottom plate and web of the main beam 2 and the lower part of the extended beam body 3 are surrounded by the plurality of steel plates 7.

[0046] As a preferred method, Figure 1-Figure 3 As shown, when the main beam 2 is extended by the extended beam body 3, the webs on the left and right sides of the cross section of the main beam 2 are thickened, and multiple full-length prestressed tendons along the length direction of the main beam 2 are arranged on the webs on both sides of the main beam 2 and the webs at corresponding positions on both sides of the extended beam body 3, and then the webs and multiple full-length prestressed tendons are poured with concrete while the main reinforcements of the main beam 2 and the extended beam body 3 are poured with concrete. The cross section of the main beam 2 after thickening is larger than the cross section of the main beam 2 before thickening, and the left and right webs of the main beam 2 are thickened by 30cm.

[0047] As a preferred method, Figure 1-Figure 3 As shown, when the main beam 2 is extended by the extended section beam body 3, the portion of the bottom plate of the main beam 2 located above the original abutment 5 is thickened, and the end face of the thickened main beam 2 is extended with the extended section beam body 3, so that the upper end face of the main beam 2 is flush with the upper end face of the extended section beam body. The range of 2m from the bottom plate of the main beam 2 is thickened, and the thickness of the bottom plate is 30cm. According to this section, the upper structure of the main beam 2 is extended by 6m, and the extended section beam height is 2.65m, the bottom width is 3.64m, and the top width is 5.5m.

[0048] As a preferred method, Figure 4-Figure 8 As shown, when the main beam 2 is extended by using the extended beam body 3, a plurality of corrugated tubes 8 are arranged on the main reinforcement of the main beam 2 along the length direction of the main beam 2, and each corrugated tube 8 is distributed on the bottom plate and the web of the main beam 2, and each corrugated tube 8 is located outside the original outline of the main beam 2, so that after the main reinforcement of the main beam 2 and the extended beam body 3 is poured with concrete, the web and bottom plate of the main beam 2 can be thickened while each corrugated tube 8 is fixed.

[0049] As a preferred method, Figure 4-Figure 8As shown, when multiple steel strands 9 are arranged on the main beam 2 and the extended section beam body 3, the multiple steel strands 9 are arranged on the web and bottom plate of the main beam 2 and the web and bottom plate of the extended section beam body 3 at corresponding positions, and the steel strands 9 are passed through the corrugated tube on the main beam 2 and the web corrugated tube 8 at corresponding positions on the extended section beam body 3, and then the steel strands 9 are tensioned to ensure that the structural force on the extended section beam body 3 and the main beam 2 meets the requirements. The steel strands 9 on the extended beam 3 are connected to the enlarged cross-section of the web and bottom plate of the main beam 2 to ensure that the structural force on the extended beam 3 and the main beam 2 meets the requirements. A plurality of steel strands 9 are arranged on the web of the main beam 2 with increased cross-section and the web corresponding to the extended beam 3, and 8 bundles of Φ15-5 steel strands 9 are evenly arranged on the web, and 6 bundles of Φ15-12 steel strands 9 are evenly arranged on the bottom plate with increased cross-section and the bottom plate corresponding to the extended beam 3 to ensure the force on the upper structure of the new beam.

[0050] As a preferred method, Figure 1 As shown, when the main beam 2 is extended by the extended beam body 3, a new abutment 12 is set on the side of the new pier 6 away from the pier 4, and the new abutment 12 is used to support the transition beam body 1. When the main beam 2 is extended by the extended beam body 3, the new abutment 12 is used to support the transition beam body 1, which can improve the bearing capacity of the transition beam body 1 after the extension and transformation.

[0051] As a preferred method, Figure 1 As shown, when paving the new beam span, the new beam span is constructed with bridge deck paving, anti-throwing net base, anti-throwing net and expansion joint according to the structural type and size of the original aqueduct 13.

[0052] As a preferred method, Figure 1 As shown, when paving the new beam span, polymer mortar or polymer putty is used to repair the defects on the concrete surface of the new beam span. Repairing the defects on the concrete surface of the new beam span with polymer mortar or polymer putty can improve the flatness of the beam span surface, prevent rainwater from penetrating, and further prevent the main reinforcement in the beam span from being eroded by rainwater, thereby improving the service life of the entire beam span.

[0053] As a preferred method, Figure 1 As shown, after the new beam span is paved, the concrete surface on the new beam span is coated with an anti-corrosion coating. By coating the concrete surface on the new beam span with an anti-corrosion coating, the durability of the concrete of the new beam span can be improved, thereby increasing the service life of the entire beam span.

[0054] As a preferred method, when dismantling the original abutment 5, only the part above the ground of the abutment 5 is dismantled. Dismantling only the part above the ground of the abutment 5 can save work, speed up the construction progress, and ensure the quality of the roadbed.

[0055] The above shows and describes the basic principles, main features and advantages of the present invention. Technical personnel in this industry should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A construction method for extending and reconstructing a bridge beam, used for extending and reconstructing a main beam (2) between an original bridge pier (4) and an original bridge abutment (5), characterized in that: The construction method comprises the following steps: A temporary steel pipe support (11) is set up on the ground (10), and after the main beam (2) is supported by the temporary steel pipe support (11), the original abutment (5) is removed; A new bridge pier (6) is added on the side of the original bridge abutment (5) away from the original bridge pier (4), a full-bridge support is set up on the ground (10), and the main beam (2) is extended by the full-bridge support; Chiseling away part of the concrete protective layer on the top plate and the bottom plate of the main beam (2) near one end of the newly added bridge pier (6) until the main reinforcement on the top plate and the bottom plate is exposed, retaining the longitudinal main reinforcement along the length direction of the main beam (2), extending the main beam (2) using the extended beam body (3), connecting the longitudinal main reinforcement of the main beam (2) with the main reinforcement of the extended beam body (3), and connecting the extended beam body (3) with the original aqueduct (13) through the transition beam body (1); Concrete is poured on the main reinforcement of the main beam (2) and the extended beam body (3). After the concrete reaches a predetermined strength, a plurality of steel strands (9) are arranged on the main beam (2) and the extended beam body (3), and the steel strands (9) are kept in a tensioned state. The main beam (2) and the extended beam body (3) form a new beam span, and the new beam span is supported (3) by newly added piers (6) to increase the span of the main beam (2); After the new beam span reaches the predetermined strength, the temporary support (21) and the full-span support are removed, and the new beam span is paved.

2. The construction method for extending and reconstructing a bridge beam as claimed in claim 1, characterized in that: When the main beam (2) is extended by using the extended beam body (3), the concrete on the web and bottom plate of the main beam (2) is roughened, and a plurality of steel plates (7) are fixed on the bottom plate and web of the main beam (2) by using a gluing process and anchor bolt fixing methods, and anchor nails are welded on each steel plate (7), and the anchor nails are welded to the main reinforcement on the extended beam body (3), so that the plurality of steel plates (7) are connected to each other to form a U-shaped structure, and the bottom plate and web of the main beam (2) and the lower part of the extended beam body (3) are surrounded by the plurality of steel plates (7).

3. The construction method for extending and reconstructing a bridge beam as claimed in claim 2, characterized in that: When the main beam (2) is extended by using the extended beam body (3), the webs on the left and right sides of the cross section of the main beam (2) are thickened, and a plurality of full-length prestressed tendons along the length direction of the main beam (2) are arranged on the webs on both sides of the main beam (2) and the webs at corresponding positions on both sides of the extended beam body (3). Then, while pouring concrete on the main beam (2) and the extended beam body (3), the webs and the plurality of full-length prestressed tendons are poured concrete.

4. The construction method for extending and reconstructing a bridge beam as claimed in claim 1, characterized in that: When the main beam (2) is extended by using the extended beam body (3), the portion of the bottom plate of the main beam (2) located above the original abutment (5) is thickened, and the end face of the thickened main beam (2) is extended with the extended beam body (3) so that the upper end face of the main beam (2) is flush with the upper end face of the extended beam body.

5. The construction method for extending and reconstructing a bridge beam as claimed in claim 3, characterized in that: When the main beam (2) is extended by using the extended beam body (3), a plurality of corrugated tubes (8) are arranged on the main reinforcement of the main beam (2) along the length direction of the main beam (2), each corrugated tube (8) is distributed on the bottom plate and the web of the main beam (2), and each corrugated tube (8) is located outside the original outline of the main beam (2), so that after the main reinforcement of the main beam (2) and the extended beam body (3) is poured with concrete, the web and bottom plate of the main beam (2) are thickened and each corrugated tube (8) is fixed.

6. The construction method for extending and reconstructing a bridge beam as claimed in claim 4, characterized in that: When a plurality of steel strands (9) are arranged on the main beam (2) and the extended section beam body (3), the plurality of steel strands (9) are arranged on the web and bottom plate of the main beam (2) and the web and bottom plate of the extended section beam body (3) at corresponding positions, and the steel strands (9) are passed through the corrugated pipe on the main beam (2) and the web corrugated pipe (8) at corresponding positions on the extended section beam body (3), and then the steel strands (9) are tensioned to ensure that the structural forces on the extended section beam body (3) and the main beam (2) meet the requirements.

7. The construction method for extending and reconstructing a bridge beam as claimed in claim 1, characterized in that: When the main beam (2) is extended by using the extended section beam body (3), a new abutment (12) is set up on the side of the new pier (6) away from the pier (4), and the new abutment (12) is used to support the transition section beam body (1).

8. The construction method for extending and reconstructing a bridge beam as claimed in claim 1, characterized in that: When paving the new beam span, the new beam span is constructed with the bridge deck paving, anti-throwing net base, anti-throwing net and expansion joint according to the structural type and size of the original aqueduct (13).

9. The construction method for extending and reconstructing a bridge beam as claimed in claim 1, characterized in that: When paving the new beam span, polymer mortar or polymer putty is used to repair the defects of the concrete surface on the new beam span.

10. The construction method for extending and reconstructing a bridge beam as claimed in claim 1, characterized in that: After paving the new beam span, the concrete surface on the new beam span is coated with anti-corrosion paint to improve the durability of the concrete.

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