Partially prestressed bridge transition slab structure for preventing bumping at bridgehead
Through the overall connection structure of the first-length plate and the reinforced concrete plate, the problem of jumping from the bridge head is solved, and a bridge plate building solution with simple construction, low cost and high efficiency is achieved.
Patent Information
- Application Number
- CN202422784380.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-15
- Publication Date
- 2025-07-11
- Estimated Expiration
- 2034-11-15
AI Technical Summary
The phenomenon of jumping from the bridge head is due to the different settlement amount of bridge and bridge head roadbed, which causes the air to be suspended below the slab and is prone to breaking. The construction of existing post-tension prestressed slabs is complex and costly.
The first-stretched plate and the reinforced concrete plate are connected through self-stressed joints to form an integral structure. The prestress of the first-stretched plate is used to offset the vehicle load, and the connection strength is improved by combining the micro-expansion joints and high-expansion joints. The factory prefabricated method is adopted.
It avoids breakage of boards, reduces construction difficulty and cost, improves construction efficiency, and ensures that there is no jumping of vehicles at the bridgehead.
Smart Images
Figure CN223088265U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a transition slab structure, and more specifically, to a partially prestressed bridge transition slab structure for preventing vehicle bump at bridge head. Background Art
[0002] Vehicle bump at bridge head has always been a difficult problem in highway construction. Due to the different settlement amounts between the bridge and the subgrade at the bridge head, the settlement amount of the subgrade at the bridge head is relatively large. It is within a reasonable range that the subgrade settles by 10 cm - 20 cm after 1 - 2 years of highway operation, while the settlement amount of the bridge abutment is relatively small, usually 1 - 2 cm. Therefore, the subgrade fill under the transition slab on the outer side of the bridge back wall is prone to settlement and void formation, forming a suspended part of the subgrade under the transition slab. The transition slab at the position of the suspended part of the subgrade loses the support of the subgrade fill, and is prone to fracture of the transition slab when a vehicle with a large load passes by, resulting in vehicle bump at bridge head.
[0003] Currently, in order to avoid vehicle bump at bridge head caused by the fracture of the transition slab, the transition slab above the part where the transition slab is prone to suspension is made into a post-tensioned prestressed slab. However, the manufacturing process of the post-tensioned prestressed slab is complex, requiring on-site installation of tensioning equipment, with high construction difficulty, long construction period, and relatively high cost. Therefore, the utility model proposes a partially prestressed bridge transition slab structure for preventing vehicle bump at bridge head using a pre-tensioned slab. Summary of the Invention
[0004] The utility model aims to overcome the above-mentioned technical problems and provides a partially prestressed bridge transition slab structure for preventing vehicle bump at bridge head.
[0005] The partially prestressed bridge transition slab structure for preventing vehicle bump at bridge head of the utility model includes a left - hand transition slab, a right - hand transition slab and a micro - expansion joint. Both the left - hand transition slab and the right - hand transition slab are composed of a pre - tensioned slab, a reinforced concrete slab and a self - stress joint; characterized in that: the pre - tensioned slab is arranged on the side of the front wall close to the bridge, and the reinforced concrete slab is arranged on the side of the front wall far from the bridge; one end of the pre - tensioned slab is placed on the corbel of the bridge, and the other end is connected to the reinforced concrete through the self - stress joint; the left - hand transition slab and the right - hand transition slab are connected through the micro - expansion joint.
[0006] In the partially prestressed bridge transition slab structure for preventing vehicle bump at bridge head of the utility model, the pre - tensioned slab is composed of a first concrete, steel strands and pre - tensioned slab transverse bars cast therein. The length direction of the steel strands is consistent with the driving direction of the road, and the length direction of the pre - tensioned slab transverse bars is consistent with the width direction of the road. Both the steel strands and the pre - tensioned slab transverse bars are arranged in two upper and lower rows evenly.
[0007] In the partially prestressed bridge transition slab structure for preventing vehicle bump at bridge head of the utility model, the reinforced concrete slab is composed of a second concrete, concrete longitudinal bars and concrete transverse bars cast therein. The length direction of the concrete longitudinal bars is consistent with the driving direction of the road, and the length direction of the concrete transverse bars is consistent with the width direction of the road.
[0008] For the prestressed bridge approach slab structure for preventing vehicle bump at bridge head of the present utility model, the self-stressing joint is composed of high-expansion concrete and longitudinal and transverse self-stressing joint reinforcement bars cast therein. The two ends of the longitudinal self-stressing joint reinforcement bar are respectively embedded at the ends of the pretensioned slab and the reinforced concrete slab. The longitudinal self-stressing joint reinforcement bar and the transverse self-stressing joint reinforcement bar are respectively in the same direction as the road driving direction and the road width direction.
[0009] For the prestressed bridge approach slab structure for preventing vehicle bump at bridge head of the present utility model, the slightly-expanding joint is composed of slightly-expanding concrete and transverse tension reinforcement bars cast therein. The two ends of the transverse tension reinforcement bar are embedded in the sides of two adjacent pretensioned slabs or two adjacent reinforced concretes.
[0010] For the prestressed bridge approach slab structure for preventing vehicle bump at bridge head of the present utility model, the grades of the first concrete, the second concrete, the high-expansion concrete and the slightly-expanding concrete are all 35 MPa to 45 MPa. The self-stress value generated by the high-expansion concrete cast in the self-stressing joint in the road driving direction is 3 MPa to 5 MPa.
[0011] For the prestressed bridge approach slab structure for preventing vehicle bump at bridge head of the present utility model, after the pretensioned slab is connected to the reinforced concrete slab through the self-stressing joint, the length of the left approach slab or the right approach slab formed is 6 m to 10 m.
[0012] The beneficial effects of the present utility model are as follows: The prestressed bridge approach slab structure for preventing vehicle bump at bridge head of the present utility model is composed of a left approach slab and a right approach slab connected through a slightly-expanding joint. The left and right approach slabs are composed of a pretensioned slab and a reinforced concrete slab connected through a self-stressing joint. The pretensioned slab is arranged at one end close to the front wall of the bridge. During the operation of the road, when the roadbed outside the bridge settles and there is a suspended part under the approach slab, since the pretensioned slab and the reinforced concrete slab are connected through the self-stressing joint, they form a firmly-connected whole and jointly bear the load of the vehicle above. In principle, there will be no height difference on the front and rear sides of the front wall, and there will be no "vehicle bump" phenomenon. Also, due to the firm connection between the pretensioned slab and the reinforced concrete slab, the pretensioned slab will not break. Moreover, since the pretensioned slab is adopted, it can be produced by the factory prefabrication method, which is easier to ensure the quality. Compared with the existing approach slab using the post-tensioned prestressed slab, it has the advantages of relatively simple construction, high construction efficiency and low cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 is the front view of the prestressed bridge approach slab structure for preventing vehicle bump at bridge head of the present utility model;
[0014] Figure 2 is the top view of the prestressed bridge approach slab structure for preventing vehicle bump at bridge head of the present utility model;
[0015] Figure 3For Figure 2 Cross-sectional view of the A-A section in
[0016] In the figure: 1 front wall, 2 corbel, 3 suspended part below the bridging slab, 4 pretensioned slab, 5 self-stressing joint, 6 reinforced concrete slab, 7 steel strand, 8 transverse bars of the pretensioned slab, 9 first concrete, 10 longitudinal bars of the self-stressing joint, 11 transverse bars of the self-stressing joint, 12 high-expansion concrete, 13 longitudinal bars of the concrete slab, 14 transverse bars of the concrete slab, 15 second concrete, 16 left bridging slab, 17 right bridging slab, 18 slightly-expanding joint, 19 transverse tension bars, 20 slightly-expanding concrete, 21 abutment, 22 subgrade. Specific implementation mode
[0017] The present utility model will be further described below in conjunction with the accompanying drawings and embodiments.
[0018] As Figure 1 and Figure 2 shown, the front view and top view of the prestressed bridge bridging slab structure for preventing vehicle bumping at the bridge head of the present utility model are respectively given. Figure 3 The Figure 2 cross-sectional view of the A-A section in
[0019] The prestressed bridge bridging slab structure for preventing vehicle bumping at the bridge head shown is composed of a left bridging slab 16, a right bridging slab 17 and a slightly-expanding joint 18. The left bridging slab 16 and the right bridging slab 17 are connected by the slightly-expanding joint 18 to form the entire bridging slab structure. The ends of the left bridging slab 16 and the right bridging slab 17 are placed on the corbels 2 on the abutment 21, and the remaining parts are laid on the subgrade 22 outside the bridge. The road surface layer is also laid on the left bridging slab 16 and the right bridging slab 17, but the road surface layer is not shown in the figure.
[0020] The left approach slab 16 and the right approach slab 17 shown are both composed of a pre-tensioned slab 4, a reinforced concrete slab 6, and a self-stress joint 5. The pre-tensioned slab 4 is arranged on the side close to the front wall 1 of the bridge, and the reinforced concrete slab 6 is arranged on the side far from the front wall 1. The pre-tensioned slab 4 is connected to the reinforced concrete slab 6 through the self-stress joint 5. In this way, the pre-tensioned slab 4 is fixedly connected to the reinforced concrete slab 6 as a whole through the self-stress joint 5. The left approach slab 16 and the right approach slab 17 thus formed are connected as an integral approach slab through the micro-expansion joint 18 to jointly bear the vehicle load above. Even if there is a suspended part 3 under the approach slab due to the settlement of the roadbed 22 on the outside of the bridge, the pre-tensioned slab 4 will not break due to the firm connection between the pre-tensioned slab 4 and the reinforced concrete slab 6, and there will be no "bumping" phenomenon at the bridgehead. At the same time, since the pre-tensioned slab 4 is adopted instead of the post-tensioned prestressed slab (i.e., the post-tensioned slab) cast in place, it has the advantages of high construction efficiency and low cost.
[0021] The pre-tensioned slab 4 shown is composed of a first concrete 9, steel strands 7 cast in the first concrete 9, and pre-tensioned slab transverse bars 8. The length direction of the steel strands 7 is the same as the road driving direction, and the pre-tensioned slab transverse bars 8 are the same as the road width direction. The steel strands 7 are arranged at equal intervals in the width direction of the pre-tensioned slab 4, and the pre-tensioned slab transverse bars 8 are arranged at equal intervals in the length direction of the pre-tensioned slab 4, and both the steel strands 7 and the pre-tensioned slab transverse bars 8 are arranged in two rows up and down evenly. When the pre-tensioned slab 4 is precast, after the steel strands 7 are relaxed, the pre-tensioned slab 4 will have compressive self-stress in the longitudinal direction. The compressed pre-tensioned slab 4 can offset the tensile stress generated during vehicle driving to improve the firmness of the pre-tensioned slab 4.
[0022] The reinforced concrete slab 6 shown is an ordinary precast reinforced concrete slab, which is composed of a second concrete 15, longitudinal concrete slab bars 13 and transverse concrete slab bars 14 cast in the second concrete 15. The length directions of the longitudinal concrete slab bars 13 and the transverse concrete slab bars 14 are the same as the road driving direction and the road width direction respectively.
[0023] The self-stress joint 5 shown is composed of high-expansion concrete 12, longitudinal self-stress joint bars 10 and transverse self-stress joint bars 11 cast in the high-expansion concrete 12. The directions of the longitudinal self-stress joint bars 10 and the transverse self-stress joint bars 11 are the same as the road driving direction and the road width direction respectively. The two ends of the longitudinal self-stress joint bars 10 are respectively embedded in the end faces of the pre-tensioned slab 4 and the reinforced concrete slab 6. The longitudinal self-stress joint bars 10 are formed by welding two sections of steel bars, and the two sections of steel bars are respectively embedded in the pre-tensioned slab 4 and the reinforced concrete slab 6. In this way, after the self-stress joint 5 is cast, the firm connection between the pre-tensioned slab 4 and the reinforced concrete 6 is realized, enabling them to jointly bear the vehicle load.
[0024] The shown micro-expansion joint 18 is composed of micro-expansion concrete 20 and transverse tension bars 19 cast in the micro-expansion concrete 20. Both ends of the transverse tension bars 19 are embedded in the side surfaces of two adjacent pre-tensioned slabs 4 or two adjacent reinforced concrete slabs 6. After the pouring of the micro-expansion joint 18 is completed, a firm connection between the left-side slab 16 and the right-side slab 17 is achieved.
[0025] Among them, the grades of the first concrete 9, the second concrete 15, the high-expansion concrete 12, and the micro-expansion concrete 20 are all 35 MPa to 45 MPa. The self-stress value generated by the high-expansion concrete 12 poured in the self-stress joint 5 in the road driving direction is 3 MPa to 5 MPa. After the pre-tensioned slab 4 is connected to the reinforced concrete slab 6 through the self-stress joint 5, the length of the formed left-side slab 16 or right-side slab 17 is 6 m to 10 m.
Claims
1. A partially prestressed bridge approach slab structure for preventing vehicle bumping at bridge heads, comprising a left approach slab (16), a right approach slab (17) and a slightly expanded joint (18). Both the left approach slab and the right approach slab are composed of a pretensioned slab (4), a reinforced concrete slab (6) and a self-stressing joint (5); characterized in that: The pretensioned slab is arranged on one side of the front wall (1) close to the bridge, and the reinforced concrete slab is arranged on the other side of the front wall far from the bridge; one end of the pretensioned slab is placed on the corbel (2) of the bridge, and the other end is connected to the reinforced concrete through a self-stress joint; the left-side slab and the right-side slab are connected through a micro-expansion joint.
2. The pre-stressed bridge approach slab structure for preventing vehicle bump at bridge head according to claim 1, characterized in that: The pretensioned slab (4) is composed of the first concrete (9), the steel strands (7) and the transverse bars (8) of the pretensioned slab cast therein. The length direction of the steel strands is consistent with the driving direction of the road, and the length direction of the transverse bars of the pretensioned slab is consistent with the width direction of the road. The steel strands and the transverse bars of the pretensioned slab are both arranged in two upper and lower rows evenly.
3. The prestressed bridge approach slab structure for preventing vehicle bumping at bridge heads according to claim 2, wherein: The reinforced concrete slab (6) is composed of the second concrete (15), the longitudinal bars (13) and the transverse bars (14) of the concrete cast therein. The length direction of the longitudinal bars of the concrete is consistent with the driving direction of the road, and the length direction of the transverse bars of the concrete is consistent with the width direction of the road.
4. The prestressed bridge approach slab structure for preventing vehicle bump at bridge head according to claim 3, characterized in that: The self-stress joint (5) is composed of the high-expansion concrete (12), the longitudinal bars (10) and the transverse bars (11) of the self-stress joint cast therein. The two ends of the longitudinal bars of the self-stress joint are respectively embedded in the ends of the pretensioned slab (4) and the reinforced concrete slab (6). The longitudinal bars and the transverse bars of the self-stress joint are respectively consistent with the driving direction and the width direction of the road.
5. The prestressed bridge approach slab structure for preventing vehicle bump at bridge head according to claim 4, wherein: The micro-expansion joint (18) is composed of the micro-expansion concrete (20) and the transverse tension bars (19) cast therein. The two ends of the transverse tension bars are embedded in the sides of two adjacent pretensioned slabs (4) or two adjacent reinforced concrete slabs (6).
6. The prestressed bridge approach slab structure for preventing vehicle bump at bridge head according to claim 5, characterized in that: The grades of the first concrete (9), the second concrete (15), the high-expansion concrete (12) and the micro-expansion concrete (20) are all 35MPa - 45MPa. The self-stress value generated by the high-expansion concrete cast in the self-stress joint in the driving direction of the road is 3MPa - 5MPa.
7. The prestressed bridge approach slab structure for preventing vehicle bump at bridge head according to claim 5, characterized in that: After the pretensioned slab (4) is connected to the reinforced concrete slab (6) through the self-stress joint (5), the length of the formed left-side slab (16) or right-side slab (17) is 6m - 10m.