A connection structure of a secondary beam and a main beam of a variable cross-section end portion

Abstract

The utility model discloses a variable cross section end part's secondary beam and main beam connecting structure, including main beam and secondary beam, one end of secondary beam is installed with main beam, wherein: secondary beam is higher than main beam, the beam end part of secondary beam adopts variable cross section, and the bottom of variable cross section secondary beam and the bottom of main beam are in the same horizontal position, and the bottom reinforcement of secondary beam is directly anchored in main beam. The bottom reinforcement of secondary beam can be directly anchored in the inside of main beam through the variable cross section measure, realizes the load direct transmission from secondary beam to main beam, does not need to pass through the complicated hanging tendon system, makes the structure stress path clear, and the bearing is more reliable, saves the complicated process of setting up the hanging tendon under the main beam, only needs to carry out the simple variable cross section treatment at the end of secondary beam, and constructs according to the conventional reinforcement anchoring mode, greatly simplifies the on -the -spot construction difficulty, and improves the construction efficiency. Meanwhile, the bending of reinforcement according to 1:6 also accords with the conventional construction requirement, and is easy to realize.

Description

Technical Field

[0001] This utility model relates to the field of building structure engineering technology, and in particular to a connection structure for reinforced concrete beams, specifically a connection structure for secondary beams and main beams at variable cross-section ends. Background Technology

[0002] In modern building structural design, especially in commercial complexes and other applications requiring large spaces and openings, structural designers often face situations where large-span secondary beams rest on relatively smaller-span main beams. To meet structural performance requirements (such as deflection control) and architectural functional requirements (such as headroom), the height of the secondary beams often needs to be greater than that of the main beams, resulting in the bottom of the secondary beams being higher than the bottom of the main beams.

[0003] Currently, the industry mainly uses the following conventional solutions to address the connection problem where secondary beams are higher than main beams: Increasing the height of the main beam: To make the bottom of the secondary beam flush with the bottom of the main beam, or to place the secondary beam directly on the increased main beam, the height of the main beam needs to be increased. However, this practice will significantly affect the building's clear height, especially in areas with dense equipment pipelines or strict requirements on space height, and can easily cause conflicts with mechanical and electrical installations and interior decoration.

[0004] Setting up hangers: At the connection between the main and secondary beams, additional hangers (or lugs, cantilever bars) are installed below the main beam, allowing the secondary beam to transfer the load to the main beam through these hangers. This load transfer method is relatively indirect, with a complex load transfer path, which may lead to stress concentration. At the same time, the installation and construction of the hangers are relatively complex, increasing the difficulty and cost of on-site construction.

[0005] The secondary beam height is designed according to the main beam: This forces the secondary beam height to be consistent with the main beam, ensuring they connect at the same elevation. However, for large-span secondary beams, if their beam height is relatively small, it will result in a large span-to-height ratio, making deflection difficult to control and calculations prone to failure. Furthermore, to meet strength and stiffness requirements, the reinforcement ratio of the secondary beam may be excessive, leading to material waste and construction difficulties.

[0006] In summary, the solutions in the existing technologies all have their own limitations and cannot adequately balance structural performance, ease of construction, and building functional requirements.

[0007] Therefore, a new building structure is needed to effectively solve the connection problem when the secondary beam is higher than the main beam. Utility Model Content

[0008] The purpose of this utility model is to overcome the problems existing in the prior art where the secondary beam is higher than the main beam, such as affecting the net height, indirect force transmission, inconvenient construction, difficulty in controlling deflection, or excessive reinforcement ratio. It provides a secondary beam-main beam connection structure with variable cross-section ends that is structurally reasonable, transmits force directly, is easy to construct, and can effectively control the beam height of the secondary beam while meeting the net height requirements.

[0009] To achieve the above objectives, this utility model provides the following technical solution: A secondary beam and main beam connection structure with variable cross-section ends includes a main beam and a secondary beam. One end of the secondary beam is installed with the main beam, and the secondary beam is higher than the main beam. The beam end of the secondary beam adopts a variable cross-section measure so that the bottom of the secondary beam after the variable cross-section is at the same level as the bottom of the main beam. The bottom reinforcement of the secondary beam is directly anchored into the main beam.

[0010] Preferably, the bending ratio at the variable cross-section of the secondary beam is 1:6.

[0011] Preferably, the height of the secondary beam is determined based on the actual span-to-height ratio and clearance requirements, and does not need to be consistent with the height of the main beam.

[0012] Preferably, the bottom reinforcing bars of the secondary beam bend along the cross-section of the secondary beam at the variable cross-section and extend into the main beam.

[0013] Preferably, the variable cross-section is narrowed at an angle.

[0014] Preferably, the building structure is applied to the location of door and window openings, and the secondary beam is a door head beam.

[0015] Compared with the prior art, the beneficial effects of this utility model are: 1. More direct load transfer: The bottom reinforcement of the secondary beam can be directly anchored into the main beam through the variable cross-section measure, realizing the direct transfer of load from the secondary beam to the main beam without the need for a complex suspension system. This makes the stress path of the structure clear and the load-bearing capacity more reliable.

[0016] 2. More Convenient Construction: The complex process of installing stirrups under the main beam is eliminated. Only a simple cross-section modification is needed at the ends of the secondary beams, and construction is carried out using conventional rebar anchoring methods. This greatly simplifies on-site construction and improves efficiency. Furthermore, the 1:6 bending ratio of the rebar meets conventional construction requirements and is easy to implement.

[0017] 3. Effective control of beam height: The height of secondary beams can be reasonably determined based on the actual span-to-height ratio and clear height requirements, without the need to force them to be consistent with the height of the main beams. This avoids problems such as difficulty in meeting deflection calculation requirements and excessive reinforcement ratios caused by forcibly limiting the height of secondary beams, making the structural design more flexible and economical. The height of the main beams also does not need to be increased additionally for the connection of secondary beams, ensuring the building's clear height.

[0018] 4. Strong adaptability: For special cases where the position of door and window openings has strict restrictions on the bottom elevation of the beam, the variable cross-section measure of this utility model can make the end of the secondary beam rest stably on the main beam without affecting the normal setting and aesthetics of the door and window openings, demonstrating good adaptability to engineering applications. Attached Figure Description

[0019] Figure 1 This is a three-dimensional partial structural diagram of the present invention; Figure 2 This is a side view of the present invention; Figure 3 This is a schematic diagram showing the bottom reinforcement of the secondary beam anchored into the main beam.

[0020] In the diagram: 1. Main beam; 2. Secondary beam; 3. Variable cross section. Detailed Implementation

[0021] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the present invention.

[0022] This utility model provides a method such as Figure 1-3 The key to the secondary beam and main beam connection structure with variable cross-section shown lies in the use of a variable cross-section 3 at the end of the secondary beam 2, so that the connection point with the main beam 1 is at the same horizontal level, allowing the bottom reinforcement of the secondary beam 2 to be directly anchored into the main beam 1. This method eliminates the need for hanger reinforcement under the main beam 1 as in existing technologies, thus overcoming the limitations of traditional methods. Example

[0023] In the atrium of a reinforcement and renovation project, a new secondary beam 2 with a span of 16.8m needs to be added. The existing main beams 1 on both sides of this secondary beam 2 are 800mm high. If the height of the new secondary beam 2 is also calculated as 800mm, its span-to-height ratio will reach 21 (16.8m / 0.8m=21), which will make it difficult to meet the structural code requirements for beam deflection calculation. According to the project's clear height requirements, the beam height of secondary beam 2 can be taken as 950mm, at which point its span-to-height ratio is 17.7 (16.8m / 0.95m≈17.7), and the beam deflection calculation can be passed smoothly with a certain margin. However, in this case, the height of secondary beam 2 (950mm) is significantly higher than the original main beam 1 (800mm). In this case, the variable cross-section connection method of this utility model can be adopted: the cross-section is changed downward from 950mm high at the end of the secondary beam 2, so that the bottom gradually becomes shallower to 800mm high at the connection with the main beam 1, thereby achieving a flush connection with the bottom of the main beam 1. The reinforcing steel bars at the bottom of the secondary beam 2 can be directly anchored into the interior of the main beam 1, making the force transmission path direct and the construction convenient. Example

[0024] The doorway height is 2600mm, and the bottom elevation of the beam is 2.6m. The height of the second-floor staircase side beam connected to the doorway beam is 400mm, and its bottom elevation is 2.50m. In this scenario, although the bottom elevation of the secondary beam 2 (doorway beam) (2.6m) is higher than the bottom elevation of the main beam 1 (staircase side beam) (2.5m), the top elevation of the secondary beam 2 is higher than that of the main beam 1, and the actual beam height of the secondary beam 2 may need to be smaller (e.g., 300mm) to meet the clear height of the doorway. In this case, the beam height of the secondary beam 2 (doorway beam) is calculated as 300mm. After calculation and verification, the shear bearing capacity of the beam at its support can meet the requirements. Even though the overall height of the secondary beam 2 is smaller, its end can still adopt the variable cross-section 3 method of this utility model, so that the bottom of the secondary beam 2 is at the same level as the bottom of the main beam 1 at the connection with the main beam 1, thereby allowing the reinforcement of the secondary beam 2 to be directly anchored into the main beam 1. This example illustrates that the variable cross-section 3 technology of this utility model, under specific clear height constraints, can be flexibly applied to various working conditions that require adjusting the bottom elevation of the beam to achieve a flush connection, even if the actual height of the secondary beam 2 is small. This optimizes construction and force transmission without affecting the setting of door and window openings.

[0025] In actual construction, the variable cross-section 3 at the end of the secondary beam 2 is usually narrowed at an angle, with a preferred bending ratio of 1:6. This ensures both reasonable bending of the reinforcing bars and meets the structural force transmission requirements. The bottom reinforcing bars of the secondary beam 2 bend along the cross-section of the secondary beam 2 at the variable cross-section 3, eventually extending into the main beam 1 and meeting the anchorage length requirements specified in the code.

[0026] In summary, this utility model effectively solves the connection problem when the secondary beam 2 is higher than the main beam 1 by adopting the variable cross-section 3 at the end of the secondary beam 2. It achieves multiple beneficial effects such as direct force transmission, convenient construction, and flexible beam height control, and has significant practicality and promotion value.

[0027] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A secondary beam and main beam connection structure at variable cross-section ends, characterized in that, It includes a main beam and a secondary beam, one end of which is installed to the main beam, wherein: The secondary beam is higher than the main beam; The secondary beam has a variable cross-section at its ends, and the bottom of the variable cross-section secondary beam is at the same horizontal position as the bottom of the main beam. The bottom reinforcing bars of the secondary beam are directly anchored into the main beam.

2. The secondary beam and main beam connection structure at the variable cross-section end according to claim 1, characterized in that, The bending ratio at the variable cross-section of the secondary beam is 1:

6.

3. The secondary beam and main beam connection structure at the variable cross-section end according to claim 1, characterized in that, The height of the secondary beam is determined based on the actual span-to-height ratio and clearance requirements, and does not need to be consistent with the height of the main beam.

4. The secondary beam and main beam connection structure at the variable cross-section end according to claim 1, characterized in that, The bottom reinforcing bars of the secondary beam bend along the cross-section at the variable cross-section and extend into the main beam.

5. The secondary beam and main beam connection structure at the variable cross-section end according to claim 1, characterized in that, The variable cross section is narrowed at an angle.

6. The secondary beam and main beam connection structure at the variable cross-section end according to claim 1, characterized in that, This structure is applied to the location of door and window openings, and the secondary beam is the door head beam.

Images