Full concrete suspension cable-stiffened girder bridge structure and construction method

Abstract

The present invention discloses a structure and construction method of a fully concrete suspension cable stiffened girder bridge. Each suspension cable is divided into multiple segments and tensioned by multiple suspension cable steel strands to form a stressed whole. The positions connected to each hanger are all precast joint blocks; each hanger is a rigid structure with multiple hanger steel strands wrapped with UHPC (ultra-high performance concrete); corresponding to each hanger steel strand in each precast joint block, a reserved corrugated pipe is provided. By tensioning the corresponding hanger steel strands in each reserved corrugated pipe and pouring UHPC material, a connection without anchor heads is made with the corresponding hanger; the main girder anchors each hanger steel strand through multiple anchor heads. During construction, the main girder bridge tower is constructed first; then the suspension cables and the corresponding hangers are constructed. The present invention improves the structural performance of the girder bridge, reduces the influence of the bridge structural height on the clearance under the bridge, and can further reduce the later maintenance cost of the steel structure stiffened bridge.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge construction, and particularly to a fully concrete suspension stiffening girder bridge structure and a construction method thereof. Background Art

[0002] A suspension stiffening girder bridge is a structural system between a truss stiffening girder bridge and a girder bridge. By setting upper / lower suspension stiffening structures, the stiffness of the bridge structure is improved and the bridge span is increased.

[0003] In the prior art, most of the completed suspension stiffening girder bridges are of the lower suspension structure system. The structural force characteristics of the lower suspension structure system are similar to those of a stress ribbon bridge. By applying prestress to the lower suspension, the upper bridge deck is stiffened and supported. This bridge structure system has a greater impact on the clear width under the bridge and is suitable for deep valley areas.

[0004] Compared with the lower suspension stiffening bridge, the application space of the upper suspension stiffening bridge is more extensive. The shape and force characteristics of the upper suspension stiffening bridge are close to those of the upper truss stiffening bridge. Most of the existing upper truss stiffening bridges adopt steel structure stiffening structures, resulting in a large amount of on-site steel structure connection work, high engineering construction costs and high later maintenance costs.

[0005] Therefore, how to improve the structural performance and landscape effect of ordinary girder bridges, reduce the impact of the bridge structure height on the under-bridge clearance, and further reduce the later maintenance costs of steel structure stiffening bridges has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0006] In view of the above-mentioned defects of the prior art, the present invention provides a fully concrete suspension stiffening girder bridge structure and a construction method thereof, aiming to improve the structural performance of the girder bridge, reduce the impact of the bridge structure height on the under-bridge clearance, and further reduce the later maintenance costs of steel structure stiffening bridges.

[0007] To achieve the above object, the present invention discloses a fully concrete suspension stiffening girder bridge structure, including bridge towers and two suspensions symmetrically and obliquely arranged on both sides of each bridge tower in the longitudinal direction of the bridge; each suspension is connected to the main girder of the bridge through a plurality of suspenders.

[0008] Wherein, the position where each suspender is connected to the corresponding suspension divides each suspension into a plurality of segments;

[0009] The position where each suspension is connected to each suspender is a precast joint block, and the cast-in-place segment is arranged between every two precast joint blocks;

[0010] The multiple precast joint blocks and multiple cast-in-place segments of each suspension are tensioned by a plurality of suspension steel strands to form a stressed integral body;

[0011] For each of the suspension straps, multiple suspension strap steel strands are tensioned at both ends, and the two tensioning ends of each corresponding suspension strap steel strand are respectively located at one end connected to the corresponding bridge tower and one end connected to the main girder;

[0012] Each of the suspenders is a rigid structure in which multiple suspender steel strands are wrapped with UHPC ultra-high toughness concrete;

[0013] At the connection of each precast joint block with each corresponding suspender, a reserved corrugated pipe is provided. By tensioning the corresponding suspender steel strands in each reserved corrugated pipe and pouring UHPC material, an anchorless connection is made with the corresponding suspender;

[0014] At the connection of the main girder with each suspender, an anchor head is embedded, and each suspender steel strand is anchored by multiple anchor heads.

[0015] Preferably, each bridge tower is arranged on the corresponding pier and is a steel reinforced concrete structure.

[0016] Preferably, each suspension strap steel strand is a slow-bonding steel strand;

[0017] Each suspender steel strand is a precision rolled threaded steel or a slow-bonding steel strand.

[0018] Preferably, the main girder adopts a conventional prestressed concrete structure.

[0019] Preferably, the steel bars of each cast-in-place segment are modular steel bars;

[0020] Each modular steel bar can be connected to the corresponding precast joint block in a modular installation manner of inter-node steel bars.

[0021] The present invention also provides a construction method for a fully concrete suspension strap stiffened girder bridge structure, including the following steps:

[0022] Step 1, construct the main girder and each bridge tower;

[0023] Step 2, construct each suspension strap and the corresponding suspenders;

[0024] Step 3, complete the bridge;

[0025] Step 4, construct the bridge deck system.

[0026] Preferably, step 2 is specifically as follows:

[0027] Step 2.1, complete the production of each precast joint block and the production of the modular steel bars of each cast-in-place segment;

[0028] Step 2.2, hoisting each of the prefabricated node blocks, and setting a bracket corresponding to each of the prefabricated node blocks for precise positioning;

[0029] Step 2.3, installing each of the modular steel bars;

[0030] Step 2.4, installing all the hangers, and tensioning the hanger steel strands of each hanger with partial tensioning force to fix each corresponding prefabricated node block;

[0031] Step 2.5, inserting all the suspension steel strands into the suspension that has completed fixing the prefabricated node block;

[0032] Tensioning each of the suspension steel strands with partial tensioning force to reduce the force on the corresponding bracket when pouring concrete for each cast-in-place segment;

[0033] Step 2.6, pouring each of the cast-in-place segments;

[0034] Step 2.7: After the suspension straps are consolidated with the corresponding bridge towers and main beams; after the casting of the structure used for the consolidation is completed, prestressing of each suspension strap is performed in steps.

[0035] More preferably, each of the hangers is constructed in one go using a post-tensioning method.

[0036] Alternatively, each of the hangers is tensioned first and then tensioned twice to apply pressure stress reserve.

[0037] More preferably, each of the hangers is connected to the corresponding suspension straps and the main beams through wet joints after being formed, and is further tensioned according to design requirements.

[0038] Beneficial effects of the present invention:

[0039] The application of the present invention can increase the bridge span by more than 30% on the basis of the same beam height; compared with steel structure truss beam bridges of the same size, the economic cost is saved by 10%, and it has excellent durability, greatly reducing the subsequent maintenance work.

[0040] Moreover, the present invention is applied to a full concrete upper suspension belt stiffening beam bridge, which looks like a suspension bridge and greatly improves the landscape function of the bridge.

[0041] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The figure shows the overall structure of a bridge according to an embodiment of the present invention.

[0043] Figure 2 Schematic cross-sectional structure diagram showing the steel strand passing through the suspension strap in an embodiment of the present invention.

[0044] Figure 3 Partial enlarged schematic view showing the suspension strap structure including precast node blocks and cast-in-place segments in an embodiment of the present invention.

[0045] Figure 4 Schematic sectional structure diagram showing the connection of the precast node block to the main girder through the suspender in an embodiment of the present invention.

[0046] Figure 5 Schematic cross-sectional structure diagram showing the suspender in an embodiment of the present invention. Detailed implementation manners

[0047] Embodiment

[0048] As Figures 1 to 5 shown, the all-concrete suspension strap stiffening girder bridge structure includes a bridge tower 1 and two suspension straps 2 symmetrically and obliquely arranged on both sides of each bridge tower 1 in the longitudinal direction of the bridge; each suspension strap 2 is connected to the main girder 4 of the bridge through a plurality of suspenders 3.

[0049] Among them, the position where each suspender 3 is connected to the corresponding suspension strap 2 divides each suspension strap 2 into multiple segments;

[0050] The position where each suspension strap 2 is connected to each suspender 3 is a precast node block 5, and the cast-in-place segment 6 is located between every two precast node blocks 5;

[0051] The multiple precast node blocks 5 and multiple cast-in-place segments 6 of each suspension strap 2 are tensioned by a plurality of suspension strap steel strands 7 to form a stressed whole;

[0052] The multiple suspension strap steel strands 7 of each suspension strap 2 are tensioned at both ends, and the two tensioning ends of each corresponding suspension strap steel strand 7 are respectively located at one end connected to the corresponding bridge tower 1 and one end connected to the main girder 4;

[0053] Each suspender 3 is a rigid structure with multiple suspender steel strands 8 wrapped with UHPC ultra-high toughness concrete;

[0054] A reserved corrugated pipe 9 is provided at the connection between each precast node block 5 and the corresponding suspender 3. By tensioning the corresponding suspender steel strand 8 in each reserved corrugated pipe 9 and pouring UHPC material, an anchorless connection is made with the corresponding suspender 3;

[0055] An anchoring head is embedded at the connection between the main girder 4 and each suspender 3, and each suspender steel strand 8 is anchored by a plurality of anchoring heads.

[0056] In practical applications, the present invention improves the existing suspension bands and suspenders by combining the construction techniques of slow-bonded prestressed steel strands and UHPC ultra-high toughness concrete. Each suspension band 2 enables the corresponding suspension band 2 and the main girder 4 to be stressed in coordination through the control of its own linear shape, the deformation at the connection part between the corresponding suspension band 2 and the main girder 4, and the tensile forces of the multiple suspenders 3 of the corresponding suspension band 2.

[0057] In some embodiments, each bridge tower 1 is arranged on the corresponding pier and is of a steel reinforced concrete structure.

[0058] In some embodiments, each suspension band steel strand 7 is a slow-bonded steel strand;

[0059] Each suspender steel strand 8 is a precision rolled threaded steel or a slow-bonded steel strand.

[0060] In some embodiments, the main girder 4 adopts a conventional prestressed concrete structure.

[0061] In some embodiments, the steel bars of each cast-in-place segment 6 are modular steel bars;

[0062] Each modular steel bar can be connected to the corresponding precast joint block 5 in a modular installation manner of inter-joint steel bars.

[0063] The present invention also provides a construction method for a full-concrete suspension band stiffened girder bridge structure, including the following steps:

[0064] Step 1, construct the main girder 4 and each bridge tower 1;

[0065] Step 2, construct each suspension band 2 and the corresponding suspenders 3;

[0066] Step 3, complete the bridge construction;

[0067] Step 4, construct the bridge deck system.

[0068] In some embodiments, Step 2 is specifically as follows:

[0069] Step 2.1, complete the production of each precast joint block 5 and the production of the modular steel bars of each cast-in-place segment 6;

[0070] Step 2.2, hoist each precast joint block 5 and set up a support for each hoisted precast joint block 5 for precise positioning;

[0071] Step 2.3, install each modular steel bar;

[0072] Step 2.4, install all the suspenders 3 and tension the suspender steel strands 8 of each suspender 3 with partial tensile force to fix the corresponding precast joint block 5;

[0073] Step 2.5, inserting all the suspension belt steel strands 7 into the suspension belt 2 after the prefabricated node block 5 is fixed;

[0074] Each suspension steel strand 7 is tensioned with partial tension force to reduce the force on the corresponding bracket when pouring concrete for each cast-in-place segment 6;

[0075] Step 2.6, pouring each cast-in-place segment 6;

[0076] Step 2.7: After the suspension straps 2 are consolidated with the corresponding bridge towers 1 and main beams 4 and the casting of the structure for consolidation is completed, each suspension strap 2 is prestressed in steps.

[0077] In some embodiments, each hanger 3 is constructed in one step using a post-tensioning method.

[0078] Alternatively, in some embodiments, each hanger 3 is pre-tensioned and then tensioned twice to apply pressure stress reserve.

[0079] In some embodiments, each suspension rod 3 is connected to the corresponding suspension strap 2 and main beam 4 through a wet joint after being formed, and is further tensioned according to design requirements.

[0080] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. The all-concrete suspension cable stiffening girder bridge structure includes bridge towers (1) and two suspension cables (2) symmetrically and obliquely arranged on both sides of each bridge tower (1) along the bridge axis; each suspension cable (2) is connected to the main girder (4) of the bridge through a plurality of suspenders (3); and it is characterized in that: The position where each suspender (3) is connected to the corresponding suspension cable (2) divides each suspension cable (2) into a plurality of segments; The position where each suspension cable (2) is connected to each suspender (3) is a precast joint block (5), and the cast-in-place segment (6) is arranged between every two precast joint blocks (5); The multiple precast joint blocks (5) and multiple cast-in-place segments (6) of each suspension cable (2) are tensioned by a plurality of suspension cable steel strands (7) to form a stressed whole; The multiple suspension cable steel strands (7) of each suspension cable (2) are tensioned at both ends, and the two tensioning ends of each corresponding suspension cable steel strand (7) are respectively located at one end connected to the corresponding bridge tower (1) and one end connected to the main girder (4); Each suspender (3) is a rigid structure with a plurality of suspender steel strands (8) wrapped with UHPC ultra-high toughness concrete; A reserved corrugated pipe (9) is provided at the connection between each precast joint block (5) and the corresponding suspender (3). By tensioning the corresponding suspender steel strand (8) in each reserved corrugated pipe (9) and pouring UHPC material, an anchorless connection is made with the corresponding suspender (3); An anchoring head is embedded at the connection between the main girder (4) and each suspender (3), and each suspender steel strand (8) is anchored by a plurality of anchoring heads; Each bridge tower (1) is arranged on the corresponding pier and is a steel-concrete composite structure; Each suspension cable steel strand (7) is a slow-bonding steel strand; Each suspender steel strand (8) is a precision rolled threaded steel or a slow-bonding steel strand; The main girder (4) adopts a conventional prestressed concrete structure; The steel bars of each cast-in-place segment (6) are modular steel bars; Each modular steel bar can be connected to the corresponding precast joint block (5) in a modular installation manner of inter-span steel bars.

2. The construction method of the all-concrete suspension cable stiffened beam bridge structure according to claim 1, characterized in that, It includes the following steps: Step 1, construct the main girder (4) and each bridge tower (1); Step 2, construct each suspension cable (2) and the corresponding suspender (3); Step 3, complete the bridge construction; Step 4, construct the bridge deck system.

3. The construction method of the all-concrete suspension cable stiffened girder bridge structure according to claim 2, characterized in that, Step 2 is specifically as follows: Step 2.1, complete the production of each precast joint block (5) and the production of the modular steel bars of each cast-in-place segment (6); Step 2.2, hoist each precast joint block (5) and set up a support for each precast joint block (5) for precise positioning; Step 2.3, install each modular steel bar; Step 2.4, install all suspenders (3) and tension the suspender steel strands (8) of each suspender (3) with partial tensile force to fix the corresponding precast joint block (5); Step 2.5, thread all the suspension cable steel strands (7) through the suspension cable (2) for which the precast joint block (5) has been fixed; Each suspension steel strand (7) is tensioned with a partial tensioning force to reduce the force on the corresponding support when the concrete of each cast-in-place segment (6) is poured; Step 2.6, casting each of the cast-in-place segments (6); Step 2.7, after the suspension straps (2) are fixed to the corresponding bridge towers (1) and the main beams (4); after the casting of the structure for fixing is completed, each suspension strap (2) is prestressed in steps.

4. The construction method of the all-concrete suspension cable stiffening girder bridge structure according to claim 3, characterized in that, Each of the suspension rods (3) is constructed in one step by adopting the post-tensioning method.

5. The construction method of the all-concrete suspension cable stiffened girder bridge structure according to claim 3, characterized in that, Each of the suspension rods (3) uses a pre-tensioning method plus secondary tensioning to apply pressure stress reserve.

6. The construction method of the all-concrete suspension cable stiffened girder bridge structure according to claim 4 or 5, characterized in that After being formed, each of the suspension rods (3) is connected to the corresponding suspension belt (2) and the main beam (4) through a wet joint and is further tensioned according to design requirements.

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