Variable-diameter steel bar special for bridge
By designing special variable-diameter steel bars for bridges that are thick in the middle and thin at both ends, the problem of waste of equal-diameter steel bars was solved, and the amount of steel bars used and the project cost were reduced.
Patent Information
- Application Number
- CN202422307838.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-23
- Publication Date
- 2025-09-23
- Estimated Expiration
- 2034-09-23
AI Technical Summary
The use of equal-diameter steel bars in existing bridge construction leads to serious waste of steel bars, especially when redundancy needs to be left to meet bending moment requirements, which increases project costs.
A special bridge-specific variable-diameter steel bar design with a thick middle and thin ends is adopted. The steel bar utilization rate is improved by designing a large-diameter section in the middle of the steel bar unit and small-diameter sections at both ends.
On the basis of meeting the requirements of bridge design, the amount of steel bars used can be reduced, the project cost can be lowered, and the utilization rate of steel bars can be improved.
Smart Images
Figure CN223373579U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of highway and urban road bridge construction, in particular to a special variable diameter steel bar for bridges. Background Art
[0002] Bridge reinforcement is primarily used to improve a bridge's load-bearing capacity, crack resistance, and stability. Bridge engineering often requires a large amount of reinforcement. For example, continuous beams primarily rely on longitudinal reinforcement to resist bending moments. The greater the bending moment, the larger the required longitudinal reinforcement area. Another example is a steel-concrete composite cantilever beam, where the fixed end often needs to withstand significant bending moments. Therefore, when configuring uniform diameter reinforcement, a certain amount of redundancy must be left at the free end.
[0003] Currently, the steel bars used in bridge construction are all of uniform diameter. Large-diameter longitudinal reinforcement is often used to meet the bending resistance requirements of continuous beams, requiring a certain amount of redundancy at both ends, resulting in significant steel waste. For cantilever beams, if transverse reinforcement is configured based on the requirements of the fixed ends and redundancy exists at the free ends, this results in significant steel waste. Therefore, reducing steel usage while still meeting bending moment requirements is crucial for reducing bridge investment. Summary of the Invention
[0004] In view of this, the utility model proposes a variable diameter steel bar specially used for bridges, which is a variable diameter steel bar with a thick middle and thin ends, thereby improving the utilization rate of the steel bar, reducing the amount of steel bar used, and lowering the project cost.
[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:
[0006] The variable diameter steel bar for bridges described in the utility model comprises a steel bar unit, wherein the steel bar unit is an integrally formed structure, and the diameter of the middle part of the steel bar unit is D Larger than the diameter at both ends d ;
[0007] The steel bar unit has a pair of variable diameter sections symmetrically arranged along its middle, and the diameter of the large diameter end of the variable diameter section is equal to the diameter D , the diameter of its small diameter end is equal to the said diameter.
[0008] The beneficial effect is that the steel bar unit of the present invention is a variable diameter structure with a thick middle part and thin ends. The middle part with a larger diameter can meet the needs of resisting bending moment loads, and the two ends are small diameter sections. On the basis of meeting the requirements of bridge design, it reduces the amount of steel bars used and thus reduces the project cost.
[0009] In a preferred embodiment of the present invention, the steel bar unit is formed by connecting two variable diameter sections. That is, the diameter of the steel bar unit of the present invention gradually decreases from the middle to the ends, and can be used as the transverse reinforcement of the cantilever beam, thereby improving the utilization rate of the reinforcement and reducing the amount of transverse reinforcement required in the cantilever beam.
[0010] Preferably, the steel bar unit further comprises a connecting section and two lengthened sections, wherein the connecting section and the lengthened section are both equal diameter sections, and the diameter of the connecting section is equal to D , the diameter of the extended section is equal to d The ends of the connecting section are respectively connected to the large-diameter ends of the variable-diameter sections, and the small-diameter ends of each variable-diameter section are connected to an extended section. The beneficial effect is that for continuous beams, the longitudinal length of a single span is often long. The present invention designs the steel bar unit as a combination of a constant-diameter section and a variable-diameter section, with a thicker middle section and thinner ends. This not only meets the requirements for resisting bending moments, but also minimizes the amount of steel bars used, reducing construction costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 This is the first schematic diagram of the present invention.
[0012] Figure 2 yes Figure 1 Figure 2 shows the application of reinforcement elements in steel-concrete composite cantilever beams.
[0013] Figure 3 This is a second schematic diagram of the present invention.
[0014] Figure 4 yes Figure 3 Figure 2 shows the application of reinforcement elements in continuous beams. DETAILED DESCRIPTION
[0015] The following is a detailed description of an embodiment of the present invention in conjunction with the accompanying drawings. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process. However, the protection scope of the present invention is not limited to the following embodiment.
[0016] Implementation Method 1
[0017] Combine Figure 1-2 It can be seen that the bridge-specific variable diameter steel bar described in this embodiment includes an integrally formed steel bar unit, which has two symmetrical variable diameter sections 1, and the diameter of the large diameter end of the variable diameter section 1 is equal to D , the diameter of the small diameter end of the variable diameter section 1 is equal to d The large diameter ends of the two variable diameter sections 1 are connected. That is, the steel bar unit gradually tapers from its center to both ends, which is particularly suitable for the transverse reinforcement of steel-concrete composite cantilever beams.
[0018] Take a box girder 2 of a steel-concrete composite cantilever beam as an example. Its length is 1.5 m and the bridge deck width is 16.56 m. If traditional uniform diameter steel bars are used, 12 uniform diameter steel bars with a diameter of 22 mm are required to meet the design requirements, and the steel consumption per box girder is 2.35 t. If the variable diameter steel bars of the utility model are used, D 22 mm, d The diameter of the steel bars is 10 mm, which meets the bending design requirements, and the total steel consumption is 1.62 t. The results show that the variable diameter steel bars of this utility model have a high utilization rate and can reduce the steel consumption of the cantilever beam by approximately 31.3%, thereby reducing the total construction cost.
[0019] Implementation Method 2
[0020] Combine Figure 3-4 It can be seen that this embodiment proposes a bridge-specific variable diameter steel bar, including an integrally formed steel bar unit, the steel bar unit having two symmetrical variable diameter sections 1, the diameter of the large diameter end of the variable diameter section 1 is equal to D , the diameter of the small diameter end of the variable diameter section is equal to d ;
[0021] The steel bar unit also includes a connecting section 3 and two extended sections 4. The connecting section 3 and the extended section 4 are both equal diameter sections. The diameter of the connecting section 3 is equal to D , the diameter of the extended section is equal to d Wherein, the two ends of the connecting section 3 are respectively connected to the large diameter end of the variable diameter section 1, and the small diameter end of each variable diameter section 1 is connected to an extended section.
[0022] That is, the middle part of the steel bar unit in this embodiment is a large-diameter equal-diameter section, and the two ends are small-diameter equal-diameter sections. The large-diameter equal-diameter section and the small-diameter equal-diameter section are connected by a variable-direction section, which can be used as the longitudinal reinforcement of the continuous beam 5. On the basis of meeting its resistance to bending moment, it can also reduce the amount of steel bars used as much as possible and reduce the project cost.
[0023] Taking a 5-meter-long continuous beam with a cross-sectional size of b×h=200 mm×450 mm as an example, if traditional constant-diameter steel bars are used, three constant-diameter steel bars with a diameter of 18 mm are required to meet the design requirements, and the total steel bar consumption is 29.964 kg. However, if the variable-diameter steel bars of this embodiment are used, the diameter of the connecting section is 18 mm, the diameter of the extended section is 10 mm, and the total steel bar consumption is 19.605 kg. On the basis of meeting the requirements for resisting bending moment loads, the present invention reduces the steel bar consumption of the continuous beam by approximately 34.6%.
[0024] Finally, it should be emphasized that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments without inventive effort, or replace some of the technical features therein with equivalents. Therefore, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.
Claims
1. A variable diameter steel bar for bridges, comprising a steel bar unit, characterized in that: The steel bar unit is an integrally formed structure, and the diameter of the middle part of the steel bar unit is D Larger than the diameter at both ends d ; The steel bar unit has a pair of variable diameter sections symmetrically arranged along its middle, and the diameter of the large diameter end of the variable diameter section is equal to D , the diameter of its smaller diameter end is equal to d .
2. The variable diameter steel bar for bridges according to claim 1, characterized in that: The steel bar unit is formed by connecting two variable diameter sections.
3. The variable diameter steel bar for bridges according to claim 1, characterized in that: The steel bar unit also includes a connecting section and two extended sections, the connecting section and the extended section are both equal diameter sections, and the diameter of the connecting section is equal to D , the diameter of the extended section is equal to d Wherein, the two ends of the connecting section are respectively connected to the large diameter end of the variable diameter section, and the small diameter end of each variable diameter section is connected to an extended section.