Prefabricated assembly type cantilever plate and existing structure connecting joint
Through the technical solution of prefabricated cantilever plates connecting nodes with existing structures, the problem of insufficient anchoring of plant reinforcement in traditional new cantilever structures is solved, and high-safety and low-cost cantilever structure connection is achieved, which meets the assumption of the straight-connection calculation.
Patent Information
- Application Number
- CN202420416603.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-05
- Publication Date
- 2025-03-28
- Estimated Expiration
- 2034-03-05
AI Technical Summary
The safety of the anchoring of the traditional newly added cantilever structure is insufficient, which is difficult to meet the calculation assumptions, the construction quality is difficult to guarantee, and there are safety hazards and high renovation costs.
A technical solution to connect nodes with prefabricated cantilever plates with existing structures is adopted. By chiseling a partial steel bar protective layer on the top of the existing structural beams and floor slabs, beard bars are arranged to penetrate under the longitudinal bars on the top of the beam and extend into the floor slabs, and short steel bars or bolt anchor heads are added to the ends of the beard bars to form a stable anchor connection.
The safety and reliability of the newly added cantilever structure is improved, the calculation assumption is met, the construction knock-out project volume is reduced, and the safety hazards and high costs in traditional solutions are avoided.
Smart Images
Figure CN222686221U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a connection node between a prefabricated assembled cantilever plate and an existing structure, and belongs to the field of architectural engineering technical design and construction. Background Art
[0002] With the continuous development of social economy, the refinement of architectural design is increasingly valued by construction units, and the details of architectural design are constantly processed and polished, so as to present a more reasonable and comfortable later user experience; therefore, it often happens that when the main structure of the original design has been completed, the original design building layout needs to be adjusted. At this time, the original main structure needs to be partially renovated and reinforced, which includes the top floor of the building stairwell. Under the premise of not affecting the normal use of the stairs below, the building renovation extends the floor slab into the stairwell, thereby expanding the building use space on the top floor of the stairwell to meet the corresponding renovation needs; since the construction of the original main structure has been completed, this kind of building renovation is mostly to cantilever a plate on the boundary of the original structural beam to ensure the net height of the stairs under the supplementary floor slab. The newly added cantilever plate generally adopts the following renovation construction schemes:
[0003] Solution 1
[0004] The reconstruction construction plan of adding a cantilever beam and extending it to the span behind the original main structure (such as Figure 1 This solution has a great impact on the existing structure (original main structure), and requires a large area of demolition of the existing structural floor. The renovation work is large and the cantilevered beam will affect the net height of the building stairwell. The cost of partial renovation in the later stage is too high.
[0005] Solution 2
[0006] New cantilever steel beam and steel beam concrete slab reconstruction construction plan (such as Figure 2 In this scheme, the newly added cantilevered steel beam will affect the net height of the building stairwell. The anchor bolts behind the beam will affect the appearance of the building and the long-term maintenance of the steel beam and anchor bolts will be inconvenient. The tension anchor bolts are similar to semi-hinged nodes and cannot form completely rigid boundary conditions. There are safety hazards in the cantilever structure.
[0007] Option 3
[0008] The new concrete cantilever slab is lowered in elevation and the reinforcement is planted on the side of the existing beam (such as Figure 3 In this scheme, there is a backfill layer on the newly added concrete cantilever slab, which affects the net height of the building. The load on the newly added concrete cantilever slab is large, and the quality of on-site construction of embedded reinforcement holes is difficult to ensure. The newly added concrete cantilever slab has the risk of overturning and falling, and the anchor plate on the rear side of the existing beam is inconvenient to use and maintain in the later stage.
[0009] Option 4
[0010] The top reinforcement of the newly added concrete cantilever slab is directly embedded in the existing structural beams and slabs (such as Figure 4 In this scheme, the location of the embedded reinforcement is close to the top of the beam, the anchorage depth of the embedded reinforcement is deep, the construction quality is difficult to guarantee, and the embedded reinforcement is difficult to meet the rigid connection calculation assumption. Previously, there were similar engineering accidents in which this scheme was used, resulting in the direct overturning and falling of the newly added concrete cantilever slab, and the structural safety was difficult to guarantee.
[0011] The above-mentioned common renovation and construction schemes all have certain drawbacks. For structural design, because the cantilever is a statically determinate structure, it is difficult to meet the rigid connection calculation assumption by adopting the traditional reinforcement method, and the upper steel bars of the cantilever structure are under tension. How to ensure that the newly added cantilever structure does not overturn, the structure is safe and reliable, and the amount of demolition work during the renovation construction is minimized is a difficult problem in structural design. Utility Model Content
[0012] In response to the above-mentioned engineering needs and practical technical problems, the utility model provides a prefabricated assembled cantilever plate and an existing structure connection node to solve the problems of insufficient safety of embedded reinforcement anchoring of traditional newly added cantilever structures, difficulty in meeting rigid connection calculation assumptions, and difficulty in ensuring construction quality, thereby improving the safety and reliability of the newly added cantilever structure.
[0013] The technical solution adopted by the utility model is as follows:
[0014] A connection node between a prefabricated cantilever plate and an existing structure comprises a prefabricated cantilever plate, an existing structural beam and an existing structural floor slab, wherein ribs for connection are reserved at the sides of the prefabricated cantilever plate; a local steel bar protective layer on the top of the existing structural beam and the existing structural floor slab is chiseled off to form a chiseled off area, the ribs of the prefabricated cantilever plate pass under the longitudinal bars on the top of the existing structural beam and extend to the chiseled off area of the existing structural floor slab, and an anchor is provided at the extended end of the ribs; concrete is poured in the chiseled off area of the existing structural beam and the existing structural floor slab and at the connection joints between the existing structural beam and the prefabricated cantilever plate.
[0015] As a preferred embodiment of the utility model, there are multiple chiseled areas, each of which corresponds to a beard rib, thereby further reducing the amount of knocking and smashing work in the renovation construction.
[0016] As a preferred embodiment of the present invention, the anchor piece is a short steel bar or a bolt anchor head, and the short steel bar or the bolt anchor head is welded to the beard bar.
[0017] As a preferred embodiment of the present invention, the concrete poured in the chiseled-out areas of the existing structural beams and the existing structural floor slabs and in the connecting joints between the existing structural beams and the prefabricated assembled cantilever slabs is C35 fine stone concrete.
[0018] As a preferred embodiment of the present invention, an angle steel is arranged between the outer side surface of the existing structural beam and the bottom of the prefabricated assembled cantilever plate; the angle steel is fixed to the existing structural beam by expansion bolts.
[0019] The utility model is beneficial in that:
[0020] In the house building renovation project, the utility model removes the local steel bar protective layer on the top of the existing structural beams and the existing structural floor slabs, and directly passes the top tensile steel bars (beard bars) of the newly added prefabricated assembled cantilever slabs under the longitudinal bars on the top of the existing structural beams and extends into the existing structural floor slabs, and welds short steel bars or bolt anchor heads at the ends of the top tensile steel bars (beard bars) of the newly added prefabricated assembled cantilever slabs, thereby transforming the simple reliance on the bond strength between the steel bars and concrete into the combined force of local pressure and shearing of the concrete by the bond strength plus the anchor head, forming a stable anchor connection, and finally realizing the safe and effective connection between the newly added prefabricated assembled cantilever slab and the existing structure, thereby solving the problems of insufficient safety of the traditional anchoring of the newly added cantilever structure, difficulty in meeting the rigid connection calculation assumptions, and difficulty in ensuring the construction quality, and improving the safety and reliability of the newly added cantilever structure. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a schematic diagram of the plane structure of the traditional construction scheme 1;
[0022] Figure 2 It is a cross-sectional structural diagram of the traditional construction scheme 2;
[0023] Figure 3 It is a cross-sectional structural diagram of the traditional construction scheme three;
[0024] Figure 4 It is a cross-sectional structural diagram of the traditional construction scheme 4;
[0025] Figure 5 It is a schematic diagram of the planar structure of the first embodiment of the utility model;
[0026] Figure 6 yes Figure 5 Schematic diagram of the cross-sectional structure at point A in FIG.
[0027] Figure 7 This is a schematic diagram of the planar structure of the second embodiment of the utility model;
[0028] Figure 8 yes Figure 7 Schematic diagram of the cross-sectional structure at point B in FIG.
[0029] Meaning of the reference numerals in the figures:
[0030] 1- Prefabricated cantilever slab, 2- Chiseled area, 3- Beam top longitudinal reinforcement, 4- Anchorage;
[0031] 5-connecting joint, 6-short steel bar, 7-angle steel, 8-expansion bolt, 9-bolt anchor head;
[0032] 10-temporary support for construction, 11-beard reinforcement. DETAILED DESCRIPTION
[0033] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.
[0034] Embodiment 1
[0035] like Figure 5 and 6 As shown, the present embodiment is a connection node between a prefabricated cantilever plate and an existing structure, comprising a prefabricated cantilever plate 1, an existing structural beam and an existing structural floor slab, and ribs 11 for connection are reserved at the sides of the prefabricated cantilever plate 1; a local steel bar protective layer on the top of the existing structural beam and the existing structural floor slab is chiseled out to form a chiseled out area 2, and the ribs 11 of the prefabricated cantilever plate 1 pass under the longitudinal bars 3 on the top of the existing structural beam and extend into the chiseled out area 2 of the existing structural floor slab, and an anchor 4 is provided at the extended end of the ribs 11; concrete is poured in the chiseled out area 2 of the existing structural beam and the existing structural floor slab and at the connection joint 5 between the existing structural beam and the prefabricated cantilever plate 1.
[0036] The anchor member 4 in this embodiment is a short steel bar 6 , and the short steel bar 6 is welded to the beard bar 11 .
[0037] In this embodiment, the concrete poured in the chiseled-out area 2 of the existing structural beam and the existing structural floor slab and in the connecting joint 5 between the existing structural beam and the prefabricated assembled cantilever slab 1 is C35 fine stone concrete.
[0038] In this embodiment, an angle steel 7 is arranged between the outer side surface of the existing structural beam and the bottom of the prefabricated assembled cantilever plate 1; the angle steel 7 is fixed to the existing structural beam by means of expansion bolts 8.
[0039] Embodiment 2
[0040] like Figure 7 and 8 As shown, this embodiment is a connection node between a prefabricated cantilever plate and an existing structure. The structure of this embodiment is similar to that of the first embodiment, and the difference is only that:
[0041] In the present embodiment, there are multiple chiseled-out areas 2, and each chiseled-out area 2 corresponds to a rib 11, thereby further reducing the amount of knocking and smashing work in the renovation construction; the anchor 4 in the present embodiment is a bolt anchor head 9, and the bolt anchor head 9 is welded to the rib 11.
[0042] In the housing construction renovation project, the utility model removes the local steel bar protective layer on the top of the existing structural beam and the existing structural floor slab, and directly passes the top tensile steel bar (beard bar 11) of the newly added prefabricated assembled cantilever plate 1 under the beam top longitudinal bar 3 of the existing structural beam and extends into the existing structural floor slab, and welds short steel bars 6 or bolt anchor heads 9 at the ends of the top tensile steel bars (beard bar 11) of the newly added prefabricated assembled cantilever plate 1, thereby transforming the simple reliance on the bond strength of the steel bar and the concrete into the combined force of the bond strength plus the anchor head on the local pressure and shearing of the concrete, forming a stable anchor connection, and finally realizing the safe and effective connection between the newly added prefabricated assembled cantilever plate 1 and the existing structure, changing the disadvantage that the traditional direct reinforcement connection between the newly added cantilever plate and the existing structure is difficult to meet the rigid connection calculation assumption, thereby:
[0043] (1) Since the prefabricated cantilever plate 1 is connected to the existing structure, and angle steel 7 is added under the prefabricated cantilever plate 1 for support, and temporary construction support 10 is used during construction, it is not necessary to support the formwork at the stairwell opening during the construction process, and the steel bars of the prefabricated cantilever plate 1 can be undisturbed before the construction is completed, which effectively ensures the safety and reliability of the structure; solves the problem of the difficulty and difficulty of supporting the formwork for the traditional subsequent supplementary plate in the existing building, reduces the construction difficulty and ensures the engineering quality of the newly added cantilever structure;
[0044] (2) Compared with the traditional plan 1 (a reconstruction construction plan in which a cantilever beam is added and extended to the span behind the original main structure), the net height of the building staircase is not affected, the amount of reconstruction of the existing structure can be minimized during the construction process, and the durability and safety of the original structural components are not affected;
[0045] (3) Compared with the traditional plan 2 (adding cantilevered steel beams and the reconstruction of concrete slabs on steel beams), the durability and corrosion resistance of concrete structures are better than those of steel structures, and the clear height of the building staircase is not affected;
[0046] (4) Compared with the traditional scheme 3 (adding a new concrete cantilever slab with a lower elevation and anchoring the existing beam side with steel bars), there is no backfill layer on the slab, the load on the cantilever end is smaller, the net height of the building staircase is better, no steel bars are required, and the structural safety and construction quality are easier to ensure;
[0047] (5) Compared with the traditional scheme 4 (adding the top reinforcement of the concrete cantilever slab directly embedded in the existing structural beam and slab), the top tensile reinforcement (bearded reinforcement 11) of the prefabricated assembled cantilever slab 1 is not embedded in the construction, and the anchorage is safe and reliable, which can meet the rigid connection calculation assumption between the new cantilever structure and the existing structure;
[0048] (6) Short steel bars 6 or bolt anchor heads 9 are welded to the ends of the tension steel bars (beard bars 11) at the top of the prefabricated cantilever slab 1, which plays the same role as the traditional tension anchoring on both sides of the existing structural beam and effectively conceals the anchor 4. The outer concrete ensures the durability of the anchor 4, strengthens the safety of the subsequent tension anchoring, and enhances the safety performance of the newly added cantilever structure against overturning.
[0049] In the description of the present invention, it is necessary to understand that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.
[0050] In the description of the present utility model, it should be noted that: unless otherwise clearly stipulated and limited, the terms "installation", "connection", "setting" and "formation" should be understood in a broad sense; for example: it can be a fixed connection, setting, or a detachable connection, setting, or an integrated structure; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements; for those skilled in the art, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances.
[0051] In the description of the present invention, reference to terms such as "embodiment", "specific example" or "practical application" means that the specific features, structures, materials or characteristics described in combination with the embodiment are included in at least one embodiment or example of the present invention; the schematic expressions of the above terms do not necessarily refer to the same embodiment or example, and the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples.
[0052] The above embodiments are only used to illustrate the technical solutions of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form, and any technical solutions obtained by equivalent replacement or equivalent transformation shall fall within the protection scope of the present invention.
Claims
1. A connection node between a prefabricated cantilever plate and an existing structure, characterized in that: It comprises a prefabricated cantilever plate, an existing structural beam and an existing structural floor slab, wherein ribs for connection are reserved at the sides of the prefabricated cantilever plate; a local steel bar protective layer on the top of the existing structural beam and the existing structural floor slab is chiseled off to form a chiseled off area; the ribs of the prefabricated cantilever plate pass under the longitudinal bars on the top of the existing structural beam and extend to the chiseled off area of the existing structural floor slab, and an anchor is arranged at the extended end of the ribs; concrete is poured in the chiseled off area of the existing structural beam and the existing structural floor slab and at the connecting joints between the existing structural beam and the prefabricated cantilever plate.
2. A prefabricated cantilever plate and existing structure connection node according to claim 1, characterized in that: There are multiple chiseled-out areas, and each chiseled-out area corresponds to a beard tendon.
3. The connection node between a prefabricated cantilever plate and an existing structure according to claim 1, characterized in that: The anchoring piece is a short steel bar or a bolt anchor head, and the short steel bar or the bolt anchor head is welded to the beard bar.
4. The connection node between a prefabricated cantilever plate and an existing structure according to claim 1, characterized in that: The concrete poured in the chiseled areas of the existing structural beams and the existing structural floor slabs and in the connecting joints between the existing structural beams and the prefabricated assembled cantilever slabs is C35 fine aggregate concrete.
5. The connection node between a prefabricated cantilever plate and an existing structure according to claim 1, characterized in that: Angle steel is arranged between the outer side surface of the existing structural beam and the bottom of the prefabricated assembled cantilever plate.
6. The connection node between a prefabricated cantilever plate and an existing structure according to claim 5, characterized in that: The angle steel is fixed on the existing structural beam by expansion bolts.