A node structure of a precast beam and a precast column with impact shear failure resistance

Abstract

The application relates to the field of building structures and discloses a node structure of a prefabricated beam and a prefabricated column with anti-punching failure performance, which comprises a prefabricated column, a connecting ring and a plurality of prefabricated beams, the outer part of the prefabricated column is sleeved with the connecting ring for bearing constraint force, and a reinforcing mesh for generating a membrane effect is connected between the connecting ring and the prefabricated column; the outer part of the connecting ring is connected with the plurality of prefabricated beams, the plurality of prefabricated beams jointly act on the connecting ring, and the connecting ring is in a tensile force balance state; the reinforcing mesh with tensile properties is arranged between the connecting ring and the prefabricated column; when the prefabricated column is damaged, the load transmission between the prefabricated column and the prefabricated beam is adjusted by the membrane effect generated by the reinforcing mesh, so that the damage of the structure under an extreme condition is delayed, the component punching damage is avoided to be too early, the stability of the beam-column node is increased, and the overall ductility of the frame under the extreme damage condition of the column can be obviously improved.

Description

Technical Field

[0001] This invention relates to the field of building structures, specifically a joint structure for precast beams and precast columns with resistance to punching shear failure. Background Technology

[0002] With the continuous development of economies worldwide, my country's economic output has increased rapidly, and its infrastructure construction scale has consistently ranked among the world's top. The demand for industrialization in the construction industry is becoming increasingly urgent. Prefabricated buildings are gaining wider application due to their relatively high construction efficiency, resource conservation, and reduced construction costs. In prefabricated beam-column joints, construction is generally achieved through on-site welding or bolting of steel components on precast columns and beams. However, the stress conditions in the beam-column joint area are complex, especially under extreme conditions such as earthquakes. There is often a lack of coordination in load transfer between the beam-column joint area and the precast columns and beams, leading to insufficient bearing capacity or seismic resistance. This results in low ductility and punching shear failure in the beam-column joint area. Especially for structures bearing large loads, prefabricated beam-column joint schemes are less common and are more susceptible to damage under disasters such as earthquakes, making it difficult for people to escape and causing casualties. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a load-bearing structure that can prevent premature punching failure of structural members and increase their stability. It significantly improves the overall ductility of the frame under extreme failure conditions. The specific solution is as follows:

[0004] A node structure for precast beams and columns with punching shear resistance includes a precast column, a connecting ring, and multiple precast beams. The precast column is fitted with a connecting ring for bearing constraint forces, and a steel mesh for generating a membrane effect is connected between the connecting ring and the precast column.

[0005] The steel mesh structure is either a radial structure with the precast column as the origin or a two-way tensioned beam structure.

[0006] The connecting ring is circular, and the midpoint of the connecting ring coincides with the axis of the precast column;

[0007] The inner side of the connecting ring is provided with a vertically arranged first steel grid frame, which is arranged circumferentially along the inner side of the connecting ring. The first steel grid frame is at the same height as the precast column. The first steel grid frame is welded and fixed to the connecting ring or the first steel grid frame is bound to the reinforcing mesh through a connector, which is a steel hoop ring or a concrete ring. The outer side of the connecting ring is provided with a vertically arranged second steel grid frame, which is arranged circumferentially along the outer side of the connecting ring. The second steel grid frame is at the same height as the precast column and is welded and fixed to the connecting ring.

[0008] Multiple precast beams are connected to precast columns. The upper surface of the beam at the end connected to the precast column is provided with a groove. The length of the groove matches the radius of the connecting ring. The connecting ring is embedded in the groove on the multiple precast beams. The connecting ring and the multiple grooves are fixedly connected by steel bars.

[0009] Furthermore, the precast beams, precast columns, and connecting rings are all reinforced concrete structures. The precast beams are turnbuckle beams. The connecting rings have a first grouting channel pre-reserved on the outside. The ends of the precast beams are provided with precast reinforcing bars that are inserted into the first grouting channel. Multiple reinforcing bars in the precast columns are respectively tied to multiple reinforcing bar heads of the corresponding reinforcing mesh. The connecting rings have multiple second grouting channels corresponding to the reinforcing mesh heads on the inside. Multiple reinforcing bar heads are respectively inserted into the corresponding second grouting channels.

[0010] Furthermore, the precast beams, precast columns, and connecting rings are all steel structures. The precast columns are cross-shaped steel columns, the precast beams are I-shaped steel beams, and the connecting rings are steel rings. The precast columns are welded and fixed to the ends of the reinforcing mesh, the reinforcing mesh is welded and fixed to the connecting rings, and the connecting rings are welded and fixed to the precast beams.

[0011] Furthermore, multiple steel reinforcement supports for supporting the connecting ring are provided at the bottom of the connecting ring. These steel reinforcement supports are evenly arranged along the circumference of the precast column. The bottom of the steel reinforcement supports is fixedly connected to the surface of the precast column, and the top of the steel reinforcement supports is fixedly connected to the bottom of the connecting ring.

[0012] Furthermore, an annular frame beam for bearing constraint force is provided outside the connecting ring. The connecting ring is located inside the annular frame beam. Multiple precast beams pass through the connecting ring and are connected to the annular frame beam. The combination of multiple precast beams and the connecting ring replaces the function of the steel mesh to generate a membrane effect.

[0013] Furthermore, support columns are evenly arranged around the periphery of the annular frame beam, and the precast columns located at the center of the annular frame beam may or may not be provided according to actual needs.

[0014] Compared with the prior art, the advantages of the present invention are as follows:

[0015] 1. This invention provides a steel mesh with tensile properties between the connecting ring and the precast column. When the precast column is damaged, the membrane effect generated by the steel mesh regulates the load transfer between the precast column and the precast beam, thereby delaying the failure of the structure under extreme conditions, avoiding premature punching failure of the components, increasing the stability of the beam-column joint, and significantly improving the overall ductility of the frame under extreme failure conditions.

[0016] 2. By arranging the first and second steel space frames inside and outside the connecting ring respectively, the present invention improves the lateral stiffness of the structure, significantly improves the seismic performance of the structure, and increases the reliability of the structure.

[0017] 3. The process of this invention is easy to control, which can better control the construction quality, significantly improve the prefabrication and industrialization of concrete structures, facilitate construction, reduce construction difficulty, increase the construction speed and production efficiency, shorten the construction period, and reduce the project cost.

[0018] 4. The connecting ring of the present invention can be embedded in the groove of the precast beam. The precast beam is arranged under the connecting ring to give full play to the beam's own load-bearing and force transmission functions, and can also support the self-weight of the connecting ring. This allows the connecting ring to only provide temporary support when the column suffers punching damage, and to be subjected to little or no force in daily life, thus ensuring the reliability of the connecting ring in case of emergencies. Attached Figure Description

[0019] Figure 1 This is a structural diagram of the present invention;

[0020] Figure 2 A structural diagram showing the installation of connecting rings and steel space frames within the building structure;

[0021] Figure 3 The structural diagram shows that the precast columns, precast beams, and connecting rings are made of reinforced concrete.

[0022] Figure 4 The structural drawing shows that the precast columns, precast beams, and connecting rings are made of steel.

[0023] Figure 5 Structural diagram showing the installation of a steel reinforcement support at the bottom of the connecting ring;

[0024] Figure 6 A structural diagram showing a precast beam base at the bottom of the connecting ring;

[0025] Figure 7 , Figure 8 Both structures are designed to provide constraint through ring-shaped frame beams, and to generate a membrane effect by forming a steel mesh through precast beams and connecting rings.

[0026] Figure 9 Structural diagram showing the installation of supporting columns on the outside of the ring-shaped frame beam;

[0027] Figure 10 The above diagram shows the structure without the precast columns;

[0028] Figure label:

[0029] 1. Precast column; 2. Precast beam; 3. Connecting ring; 4. Reinforcing mesh; 5. First steel space frame; 6. Second steel space frame; 7. Reinforcing bar support; 8. Groove; 9. Ring frame beam; 10. Support column. Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below, in conjunction with the appendix. Figure 1 To be continued Figure 7 The following embodiments are described in detail. These embodiments are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0031] Example 1

[0032] like Figure 1 and Figure 2 As shown, a node structure of a precast beam 2 and a precast column 1 with punching shear resistance includes a precast column 1, a connecting ring 3 and a plurality of precast beams 2. The precast column 1 is externally fitted with a connecting ring 3 for bearing constraint forces, and a steel mesh 4 for generating a membrane effect is connected between the connecting ring 3 and the precast column 1.

[0033] The external connection of the connecting ring 3 consists of multiple precast beams 2. The multiple precast beams 2 work together on the connecting ring 3, so that the connecting ring 3 is in a state of tensile equilibrium.

[0034] The connecting ring 3 can be a closed-loop structure such as a circle or a regular polygon, with the midpoint of the connecting ring 3 coinciding with the axis of the precast column 1. In this invention, an external wall can be installed around the connecting ring 3 to enclose the precast column 1, protecting both the connecting ring 3 and the precast column 1. The precast beam 2 passes through the external wall and connects to the connecting ring 3. This embodiment is suitable for buildings with high seismic resistance, such as those in earthquake-prone areas or air-raid shelters, and for small to medium-sized buildings with one or two floors and a total area not exceeding 800 square meters.

[0035] Example 2

[0036] like Figure 1 and Figure 2 The connecting ring 3 shown has a vertically arranged first steel grid 5 on its inner side. The first steel grid 5 is arranged circumferentially along the inner side of the connecting ring 3. The first steel grid 5 is at the same height as the precast column 1. The first steel grid 5 is welded and fixed to the connecting ring 3, or the first steel grid 5 is tied to the steel mesh 4 by a connector, which is a steel hoop. The connecting ring 3 has a vertically arranged second steel grid 6 on its outer side. The second steel grid 6 is arranged circumferentially along the outer side of the connecting ring 3. The second steel grid 6 is at the same height as the precast column 1. The second steel grid 6 is welded and fixed to the connecting ring 3. The outer wall is located outside the second steel grid 6.

[0037] Example 3

[0038] like Figure 3As shown, the precast beam 2, precast column 1, and connecting ring 3 are all reinforced concrete structures. The precast beam 2 is a basket beam, i.e., a cross beam. The steel mesh 4 has a radial structure with the precast column 1 as the origin. The connecting ring 3 has a first grouting channel pre-reserved on its outer side. The end of the precast beam 2 is provided with precast steel bars inserted into the first grouting channel. Multiple steel columns located in the precast column 1 are respectively tied to multiple reinforcing bars of the corresponding steel mesh 4. The connecting ring 3 has multiple second grouting channels corresponding to the reinforcing bars of the steel mesh 4 on its inner side, and multiple reinforcing bars are respectively inserted into the corresponding second grouting channels. Cement mortar is injected into the first and second grouting channels and then solidified.

[0039] like Figure 4 As shown, the precast beam 2, precast column 1, and connecting ring 3 are all steel structures. The steel mesh 4 is a two-way tensioned beam structure. The precast column 1 is a cross-shaped steel column, the precast beam 2 is an I-shaped steel beam, and the connecting ring 3 is a steel ring or a concrete ring. The precast column 1 is welded and fixed to the steel mesh 4, the steel mesh 4 is welded and fixed to the connecting ring 3, and the connecting ring 3 is welded and fixed to the precast beam 2. The connecting ring 3 and the precast beam 2 can also be fixed by driving in steel nails.

[0040] Example 4

[0041] like Figure 5 As shown, multiple steel bar supports 7 are provided at the bottom of the connecting ring 3 to support the connecting ring 3. The multiple steel bar supports 7 are evenly arranged along the circumference of the precast column 1. The bottom of the steel bar supports 7 is fixedly connected to the surface of the precast column 1, and the top of the steel bar supports 7 is fixedly connected to the bottom of the connecting ring 3.

[0042] like Figure 6 As shown, multiple precast beams 2 are connected to precast columns 1. The upper surface of the beam body at the end of the precast beam 2 connected to the precast column 1 is provided with a groove 8. The length of the groove 8 matches the radius of the connecting ring 3. The connecting ring 3 is embedded in the groove 8 on the multiple precast beams 2. The connecting ring 3 and the multiple grooves 8 are fixedly connected by steel bars.

[0043] Example 5

[0044] like Figure 7 and Figure 8 As shown, an annular frame beam 9 for bearing constraint force is provided outside the connecting ring 3. The connecting ring 3 is located inside the annular frame beam 9. Multiple precast beams 2 pass through the connecting ring 3 and are connected to the annular frame beam 9. The multiple precast beams 2 and the connecting ring 3 together replace the steel mesh 4 to produce a membrane effect.

[0045] The precast beams 2 and columns can be spliced ​​together or have holes made in them to facilitate the insertion of components. High-strength bolts are used for connection, which facilitates rapid installation and disassembly of the building, realizes the recycling of components, and is conducive to the promotion and application of prefabricated buildings.

[0046] In the above embodiment, the precast beam 2 and the connecting ring 3 are combined to replace the steel mesh 4 to generate the membrane effect. The ring beam 9 in the above structure needs to have sufficient area to ensure that the precast beam 2 and the connecting ring 3 have a certain degree of ductility, so that the precast beam 2 and the connecting ring 3 can deform through ductility when subjected to restraint force, thereby generating the membrane effect. The structure of this embodiment is suitable for buildings that require a large planar space and a large column spacing, such as large shopping malls, office buildings, underground parking lots, etc.

[0047] like Figure 9 and Figure 10 As shown, support columns 10 are evenly arranged around the annular frame beam 9. The precast columns 10 located at the center of the annular frame beam 9 may or may not be provided according to actual needs.

[0048] The above structure is an improvement based on the needs of building space. For example, if the building is a small building, it is not possible to arrange a large number of prefabricated columns 1 to support the building. Therefore, a ring-shaped frame beam 9 that occupies the entire building plane is set up, and multiple supporting columns 10 are evenly distributed around the ring-shaped frame beam 9 for support. The prefabricated column 1 at the center of the ring-shaped frame beam 9 can be set up or canceled according to actual needs.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A joint structure of precast beams (2) and precast columns (1) with resistance to punching shear failure, characterized in that, It includes a precast column (1), a connecting ring (3) and multiple precast beams (2). The precast column (1) is fitted with a connecting ring (3) for bearing the constraint force. A steel mesh (4) for generating a membrane effect is connected between the connecting ring (3) and the precast column (1). The external connection of the connecting ring (3) is a number of precast beams (2), and the multiple precast beams (2) act together on the connecting ring (3) to keep the connecting ring (3) in a state of tensile equilibrium. The steel mesh (4) structure is either a radial structure with the precast column (1) as the origin or a two-way tensioned beam structure; The connecting ring (3) is circular, and the midpoint of the connecting ring (3) coincides with the axis of the precast column (1); The inner side of the connecting ring (3) is provided with a vertically arranged first steel grid frame (5), which is arranged circumferentially along the inner side of the connecting ring (3). The first steel grid frame (5) is at the same height as the precast column (1). The first steel grid frame (5) is welded and fixed to the connecting ring (3) or the first steel grid frame (5) is tied to the steel mesh (4) by a connector, which is a steel hoop ring or a concrete ring. The outer side of the connecting ring (3) is provided with a vertically arranged second steel grid frame (6), which is arranged circumferentially along the outer side of the connecting ring (3). The second steel grid frame (6) is at the same height as the precast column (1) and is welded and fixed to the connecting ring (3). Multiple precast beams (2) are connected to precast columns (1). The upper surface of the beam body of the precast beam (2) connected to the precast column (1) has a groove (8). The length of the groove (8) matches the radius of the connecting ring (3). The connecting ring (3) is embedded in the groove (8) on the multiple precast beams (2). The connecting ring (3) and the multiple grooves (8) are fixedly connected by steel bars.

2. The joint structure of the precast beam (2) and precast column (1) with punching shear resistance according to claim 1, characterized in that, The precast beam (2), precast column (1) and connecting ring (3) are all reinforced concrete structures. The precast beam (2) is a basket beam. The connecting ring (3) has a first grouting channel reserved on the outside. The end of the precast beam (2) is provided with precast steel bars inserted into the first grouting channel. Multiple steel bars in the precast column (1) are respectively tied to multiple reinforcing bars of the corresponding steel mesh (4). The connecting ring (3) has multiple second grouting channels corresponding to the reinforcing bars of the steel mesh (4) on the inside. Multiple reinforcing bars are respectively inserted into the corresponding second grouting channels.

3. The joint structure of the precast beam (2) and precast column (1) with punching shear resistance according to claim 1, characterized in that, The precast beam (2), precast column (1) and connecting ring (3) are all steel structures. The precast column (1) is a cross-shaped steel column, the precast beam (2) is an I-shaped steel beam, and the connecting ring (3) is a steel ring. The precast column (1) is welded and fixed to the head of the reinforcing mesh (4), the reinforcing mesh (4) is welded and fixed to the connecting ring (3), and the connecting ring (3) is welded and fixed to the precast beam (2).

4. The joint structure of the precast beam (2) and precast column (1) with punching shear resistance according to claim 1, characterized in that, Multiple steel bar supports (7) supporting the connecting ring (3) are provided at the bottom of the connecting ring (3). The multiple steel bar supports (7) are evenly arranged along the circumference of the precast column (1). The bottom of the steel bar supports (7) is fixedly connected to the surface of the precast column (1), and the top of the steel bar supports (7) is fixedly connected to the bottom of the connecting ring (3).

5. The joint structure of the precast beam (2) and precast column (1) with punching shear resistance according to claim 1, characterized in that, An annular frame beam (9) for bearing constraint force is provided outside the connecting ring (3). The connecting ring (3) is located inside the annular frame beam (9). Multiple precast beams (2) pass through the connecting ring (3) and are connected to the annular frame beam (9). The multiple precast beams (2) and the connecting ring (3) together replace the steel mesh (4) to produce a membrane effect.

6. According to claim 5, the precast beam (2) and precast column (1) with punching shear resistance are provided with support columns (10) evenly arranged around the annular frame beam (9), and the precast column (1) can be provided or not provided at the center of the annular frame beam (9) according to actual needs.

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