Newly-increased bare concrete cantilever structure of existing building and connection method
Technical Field
The invention belongs to the technical field of existing building reinforcement and reconstruction, and particularly relates to a newly-added large-span bare concrete cantilever structure and a connection method for an existing building.
Background
The structure of encorbelmenting is increased all around on the basis of existing building, and the main way is: newly-increased girder steel of encorbelmenting passes through the crab-bolt to be connected with existing building structure boundary beam, corresponds newly-increased girder steel position of encorbelmenting and sets up the girder steel of being no less than 2 strides under existing structure concrete floor, and this girder steel passes through the crab-bolt with former concrete beam to be connected to solve newly-increased girder steel of encorbelmenting flange pressure torsion effect to the side roof beam production. The newly-added overhanging steel beam Liang Dingbiao is higher than the thickness of one flange of the existing building concrete floor, a continuous steel plate belt with at least 2 spans is arranged at the position, corresponding to the flange of the newly-added steel beam, of the concrete floor, the steel plate belt is connected with the flange of the newly-added steel beam through a butt welding seam, and the steel plate belt is connected with the upper flange of the newly-added steel beam below the plate through a bolt penetrating through the floor of the original structure, so that the effective transmission of the tension of the upper flange of the overhanging steel beam is ensured.
However, at present, the existing building cannot be added with a fresh water concrete cantilever structure in the prior art.
Disclosure of Invention
In view of the above analysis, the present invention aims to provide a new bare concrete cantilever structure for an existing building and a connection method thereof, and solves the problem that the existing building cannot realize the new bare concrete cantilever structure.
The purpose of the invention is mainly realized by the following technical scheme:
the invention provides a new bare concrete cantilever structure for an existing building, which comprises a new floor cantilever beam, an inner-span floor beam, a floor connecting longitudinal rib, a new roof cantilever beam, an inner-span roof beam and a roof connecting longitudinal rib; the inner span floor beam is arranged on the existing floor beam, and the newly added floor cantilever beam is connected with the inner span floor beam through a floor connecting longitudinal rib to form a floor cantilever structure; the inner span roof beam is arranged on the existing roof beam, and the newly-added roof cantilever beam is connected with the inner span roof beam through the roof connecting longitudinal rib to form a roof cantilever structure; newly-added floor cantilever beams and newly-added roof cantilever beams are clean water concrete cantilever beams; the newly added floor cantilever beam is a prefabricated part, and the inner-span floor beam is a cast-in-place part; the contact surface of the newly-added floor cantilever beam and the inner-span floor beam is zigzag, and the zigzag single-tooth shape comprises an inclined edge, a first arc-shaped edge, a vertical edge and a second arc-shaped edge which are sequentially connected; the beam top elevation of the newly-added floor cantilever beam is higher than that of the existing floor beam, the outmost floor connecting longitudinal rib at the upper part of the newly-added floor cantilever beam passes through the upper surface of the existing floor beam, and the second floor connecting longitudinal rib at the upper part of the newly-added floor cantilever beam is connected with the existing floor beam through a local pick chisel; the beam top elevation of the newly added roof cantilever beam is higher than that of the existing roof beam; the roof connecting longitudinal bars are all connected with the inner span roof beam and only pass through the upper surface of the existing roof beam.
Furthermore, the inner-span floor beam is connected with the existing floor beam through the floor shear steel bars.
Further, the floor shear reinforcement is short muscle or shaped steel.
Furthermore, the inner span roof beam is connected with the existing roof beam through the roof shear steel bar.
Further, the roof shear reinforcement is short reinforcement or shaped steel.
Furthermore, the cross section of the cantilever beam of the newly added floor is T-shaped; and/or the cross section of the newly-added roof cantilever beam is in a T shape.
Furthermore, the number of the floor connecting longitudinal ribs is multiple, and the multiple floor connecting longitudinal ribs are arranged in multiple layers; and/or the number of the roof connecting longitudinal ribs is multiple, and the multiple roof connecting longitudinal ribs are arranged in multiple layers.
Furthermore, the standard height difference between the beam top of the cantilever beam of the newly added floor and the beam top of the beam of the existing floor is 40-70mm.
Furthermore, the height difference between the beam top of the cantilever beam of the newly added floor and the beam top of the beam of the existing floor is 40mm, 48mm, 50mm, 56mm, 63mm, 66mm or 70mm.
Furthermore, the standard height difference between the beam top of the newly-added roof cantilever beam and the beam top of the existing roof beam is 180-230mm.
Furthermore, the height difference between the beam top of the newly-added roof cantilever beam and the beam top of the existing roof beam is 180mm, 200mm, 220mm or 230mm.
Further, above-mentioned existing building newly increases clear water concrete structure of encorbelmenting still includes frame post reinforcement, and frame post reinforcement includes the back up coat and locates and consolidate intraformational reinforcement short rib, and the back up coat parcel has the frame post, and the back up coat is through consolidating short rib and existing frame post fixed connection.
Furthermore, frame post reinforcement still includes the reinforcement stirrup, and the reinforcement stirrup is binded in the outer wall of back up coat.
Further, the thickness of the reinforcing layer is 150 to 250mm.
Further, the thickness of the reinforcing layer is 150mm, 165mm, 188mm, 210mm, 235mm or 250mm.
The invention also provides a connecting method of the newly-added bare concrete cantilever structure of the existing building, which is used for connecting the newly-added bare concrete cantilever structure of the existing building, and the connecting method comprises the following steps:
step 1: prefabricating a newly-added floor cantilever beam and a newly-added roof cantilever beam, inserting a floor connecting longitudinal rib into the newly-added floor cantilever beam in the process of prefabricating the newly-added roof cantilever beam of the newly-added floor cantilever beam, wherein the end part of the floor connecting longitudinal rib is exposed, inserting a roof connecting longitudinal rib into the newly-added roof cantilever beam, and the end part of the roof connecting longitudinal rib is exposed;
step 2: conveying the newly-added floor cantilever beam and the newly-added roof cantilever beam to a construction site;
and step 3: hoisting the prefabricated newly-added floor cantilever beam to a specified position on a construction site, so that the exposed floor connecting longitudinal rib is positioned above the existing floor beam;
hoisting the prefabricated newly-added roof cantilever beam to a specified position, and enabling the exposed roof connecting longitudinal rib to be positioned above the existing roof beam;
and 4, step 4: according to the design appearance of the inner span floor beam and the inner span roof beam, respectively manufacturing grouting cavities, grouting concrete slurry into the grouting cavities, respectively forming the inner span floor beam and the inner span roof beam after curing, wrapping the exposed floor connecting longitudinal rib by the inner span roof beam, wrapping the exposed roof connecting longitudinal rib by the inner span roof beam, and completing the connection of the newly-increased clear water concrete cantilever structure of the existing building.
Compared with the prior art, the invention can realize at least one of the following beneficial effects.
A) The newly-added fair-faced concrete cantilever structure of the existing building comprehensively adopts various reinforcing methods, for example, the newly-added floor cantilever beam and the inner-crossing floor beam are stably connected through the floor connecting longitudinal ribs, the newly-added roof cantilever beam and the inner-crossing roof beam are stably connected through the roof connecting longitudinal ribs, and the newly-added floor cantilever beam and the newly-added roof cantilever beam have a fair-faced concrete effect, so that the newly-added fair-faced concrete cantilever structure of the existing building can be realized.
B) According to the newly-added fair-faced concrete cantilever structure for the existing building, provided by the invention, through the arrangement of the frame beam reinforcing part, the frame column reinforcing part comprises the reinforcing layer and the reinforcing short ribs arranged in the reinforcing layer, the existing frame column is reinforced by adopting the cross section expanding method, and on one hand, the internal force of the frame column is increased due to the weight of the newly-added cantilever structure, and the stress requirement of the frame column per se needs to be met; on the other hand, the floor and the roof cantilever beam longitudinal bars can pass through the enlarged area as much as possible, and the anchoring effect of the beam longitudinal bars in the columns is enhanced.
C) In the newly-increased bare concrete cantilever structure for the existing building, in order to improve the contact stability between the newly-increased floor cantilever beam and the inner-span floor beam, the contact surface of the newly-increased floor cantilever beam and the inner-span floor beam is in a sawtooth shape, so that the roughness between the contact surfaces of the newly-increased floor cantilever beam and the inner-span floor beam is increased equivalently, and the sawtooth contact surface can effectively improve the connection strength between the newly-increased floor cantilever beam and the inner-span floor beam.
D) According to the newly-added bare concrete cantilever structure for the existing building, due to the arrangement of the sawtooth-shaped part, the problem that concrete slurry cannot be poured to the sawtooth-shaped corners can occur in the production process of the newly-added floor cantilever beam and the grouting process of the newly-added floor cantilever beam.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.
Drawings
The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout the drawings;
fig. 1 is a schematic structural diagram of a newly-added bare concrete cantilever structure of an existing building according to an embodiment of the present invention;
FIG. 2 isbase:Sub>A cross-sectional view A-A of FIG. 1;
FIG. 3 is a cross-sectional view B-B of FIG. 1;
FIG. 4 is a cross-sectional view C-C of FIG. 1;
FIG. 5 is a cross-sectional view taken along line D-D of FIG. 1;
FIG. 6 is a cross-sectional view E-E of FIG. 1;
fig. 7 is a schematic structural view of a zigzag structure of a newly added floor cantilever beam in a newly added bare concrete cantilever structure of an existing building according to a first embodiment of the present invention;
fig. 8 is a flowchart of a method for connecting a new bare concrete cantilever structure of an existing building according to a second embodiment of the present invention.
Reference numerals: 1-newly adding a floor cantilever beam; 101-a beveled edge; 102-a first arcuate edge; 103-vertical edge; 104-a second arc-shaped edge; 2-inner-crossing floor beam; 3-floor connecting longitudinal bars; 4-newly adding a roof cantilever beam; 5-inside span roof beam; 6-roof connecting longitudinal bars; 7-existing floor beam; 8-existing roof beam; 9-a reinforcing layer; 10-reinforcing short ribs; 11-existing frame posts; 12-reinforcing stirrup.
Detailed Description
The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form a part hereof, and which together with the embodiments of the invention serve to explain the principles of the invention.
The new overhanging knot solution of the existing building mainly focuses on increasing overhanging steel beams, taking measures to ensure the reliable connection of the steel beams and the main structure of the existing building and how to strengthen the anti-torsion capability of the boundary beams of the existing building structure.
Example one
This embodiment provides an existing building newly-increased clear water concrete cantilever structure, refer to fig. 1 to 7, including newly-increased floor cantilever beam 1, interior floor roof beam 2 of striding, the floor is connected and is indulged muscle 3, newly-increased roof cantilever beam 4, interior roof beam 5 and the roof are connected and indulge muscle 6, wherein, interior floor roof beam 2 of striding is located on existing floor roof beam 7, newly-increased floor cantilever beam 1 is connected through the floor and is indulged muscle 3 and be connected with interior floor roof beam 2 of striding through the floor, thereby can form the floor cantilever structure, interior roof beam 5 of striding is located on existing roof beam 8, newly-increased roof cantilever beam 4 is connected through roof connection and is indulged muscle 6 and interior roof beam 5 of striding and be connected, thereby can form the roof cantilever structure, newly-increased floor cantilever beam 1 and newly-increased roof cantilever beam 4 are clear water concrete cantilever beam, have the clear water concrete effect.
Compared with the prior art, the newly-added fair-faced concrete cantilever structure of the existing building comprehensively adopts multiple reinforcing methods, for example, the newly-added floor cantilever beam 1 and the inner-span floor beam 2 are stably connected through the floor connecting longitudinal rib 3, the newly-added roof cantilever beam 4 and the inner-span roof beam 5 are stably connected through the roof connecting longitudinal rib 6, and the newly-added floor cantilever beam 1 and the newly-added roof cantilever beam 4 have a fair-faced concrete effect, so that the newly-added fair-faced concrete cantilever structure of the existing building can be realized.
In order to ensure the transmission of force between the interface between the inner-span floor beam 2 and the existing floor beam 7, the two beams may be connected by a floor shear reinforcement (e.g., a short reinforcement or a profile steel).
Similarly, for the connection between the inner span roof beam 5 and the existing roof beam 8, the two may be connected by a roof shear bar (e.g., a short bar or a section steel, etc.) in order to ensure the transmission of interfacial forces.
In order to effectively simplify the arrangement of the floor connecting longitudinal ribs in the beam column joint core area of the newly-added floor cantilever beam 1 and efficiently exert the tensile strength of the floor connecting longitudinal ribs, the cross section of the newly-added floor cantilever beam 1 is in a T shape.
Specifically, the number of the floor connecting longitudinal ribs 3 is plural, and the plural floor connecting longitudinal ribs 3 are arranged in multiple layers. Similarly, the number of the roof connecting longitudinal ribs 6 is plural, and the plural roof connecting longitudinal ribs 6 are arranged in plural layers.
In order to reduce the damage to the existing floor beam 7, the beam top elevation of the newly added floor cantilever beam 1 is higher than that of the existing floor beam 7, and the elevation difference between the beam top elevation and the beam top elevation is 40-70mm, such as 40mm, 48mm, 50mm, 56mm, 63mm, 66mm or 70mm. Through the mode that occupies partial existing floor building for newly-increased floor cantilever beam 1 upper portion outermost floor layer is connected and is indulged muscle 3 and all pass through from the upper surface of existing floor roof beam 7, newly-increased floor cantilever beam 1 upper portion second floor layer is connected and is indulged muscle 3 and pass through the existing floor roof beam 7 of local pick chisel and be connected with existing floor roof beam 7, thereby can significantly reduce the concrete pick chisel volume to existing floor roof beam 7, reduce the damage to existing building.
Similarly, in order to reduce damage to the existing roof beam 8, the elevation of the roof of the newly-added roof cantilever beam 4 is higher than that of the existing roof beam 8, and the elevation difference between the two is 180 to 230mm, for example, 180mm, 200mm, 220mm or 230mm. By using a part of roof building, the general building requirements of the part of roof are not strict, and the structure can be utilized, so that the roof connecting longitudinal ribs 6 are all connected with the inner span roof beam 5 and only pass through the upper surface of the existing roof beam 8, and the original structure is not damaged completely.
In order to effectively simplify the arrangement of the roof connecting longitudinal ribs 6 in the beam-column joint core area of the newly-added roof cantilever beam 4 and efficiently exert the tensile strength of the roof connecting longitudinal ribs 6, the cross section of the newly-added roof cantilever beam 4 is in a T shape.
Considering the increase of the bare concrete cantilever structure, the load bearing of each original structural member of the existing building frame beam can be increased, and therefore, the newly-increased bare concrete cantilever structure of the existing building also comprises a frame column reinforcing member.
Specifically, the frame column reinforcement comprises a reinforcing layer 9 (for example, a reinforced concrete reinforcing layer) and a reinforcing short rib 10 arranged in the reinforcing layer 9, wherein the reinforcing layer 9 wraps an existing frame column 11, and the reinforcing layer 9 is fixedly connected with the existing frame column 11 through the reinforcing short rib 10. In this way, the existing frame column 11 is reinforced by adopting the cross section expanding method through the arrangement of the frame beam reinforcing parts (namely the reinforcing layer 9 and the reinforcing short ribs 10), on one hand, the internal force of the existing frame column 11 is increased due to the weight of the newly-added fresh water concrete cantilever structure, and the self stress requirement of the existing frame column 11 needs to be met; on the other hand, the floor connecting longitudinal rib and the roof connecting longitudinal rib of the newly added floor cantilever beam and the newly added roof cantilever beam can pass through the expanded region (namely the frame column reinforcing member region) as much as possible, so that the anchoring effect of the floor connecting longitudinal rib and the roof connecting longitudinal rib in the existing frame column 11 and the frame beam reinforcing member can be enhanced.
In order to further improve the overall structure intensity of the existing frame column 11, the frame column reinforcing member further comprises reinforcing stirrups 12, the reinforcing stirrups 12 are bound on the outer wall of the reinforcing layer 9, and the overall structure intensity of the existing frame column 11 can be further improved through the arrangement of the reinforcing stirrups 12.
Illustratively, the thickness of the reinforcing layer 9 is 150 to 250mm, for example, 150mm, 165mm, 188mm, 210mm, 235mm, or 250mm.
In order to effectively improve the construction efficiency, the newly-added floor cantilever beam 1 can be a prefabricated part, and the inner-span floor beam 2 is a cast-in-place part.
Considering that the construction modes are different, the contact surfaces of the new floor cantilever beam 1 and the inner-span floor beam 2 inevitably have certain difference, and in order to improve the contact stability between the new floor cantilever beam 1 and the inner-span floor beam 2, the contact surface of the new floor cantilever beam 1 and the inner-span floor beam 2 is zigzag, so that the roughness between the contact surfaces of the new floor cantilever beam 1 and the inner-span floor beam 2 is increased equivalently, and the zigzag contact surface can more effectively improve the connection strength between the new floor cantilever beam 1 and the inner-span floor beam 2.
For the zigzag single tooth shape, specifically, an inclined side 101, a first arc-shaped side 102, a vertical side 103 and a second arc-shaped side 104 are included in this order. This is because, because the setting at zigzag position, can appear the unable problem of pouring into the zigzag corner of concrete slurry in the production process of newly-increased floor cantilever beam 1 and the grout in-process of newly-increased floor cantilever beam 1, through the design to the monodentate shape, concrete slurry can flow into the zigzag corner along inclined edge 101 and first arc limit 102, then, flows into next monodentate along vertical limit 103 and second arc limit 104 to can guarantee that concrete slurry can pour into the zigzag corner.
Example two
The embodiment also provides a connection method of a newly-added bare concrete cantilever structure of an existing building, which is used for the connection of the newly-added bare concrete cantilever structure of the existing building in the first embodiment with reference to fig. 8, and the connection method includes the following steps:
step 1: prefabricating a newly-added floor cantilever beam and a newly-added roof cantilever beam, inserting a floor connecting longitudinal rib into the newly-added floor cantilever beam in the process of prefabricating the newly-added floor cantilever beam and the newly-added roof cantilever beam, wherein the end part of the floor connecting longitudinal rib is exposed, inserting a roof connecting longitudinal rib into the newly-added roof cantilever beam, and the end part of the roof connecting longitudinal rib is exposed;
step 2: respectively conveying the prefabricated newly-added floor cantilever beam and the newly-added roof cantilever beam to a construction site;
and step 3: hoisting the prefabricated newly-added floor cantilever beam to a designed designated position on a construction site, so that the exposed floor connecting longitudinal rib is positioned above the existing floor beam and in the design space of the inner-span floor beam;
in a construction site, hoisting a prefabricated newly-added roof cantilever beam to a designed designated position, so that the exposed roof connecting longitudinal rib is positioned above the existing roof beam and in the design space of the inner-span roof beam;
and 4, step 4: according to the design appearance of the inner-span floor beam and the inner-span roof beam, grouting cavities for the inner-span floor beam and the inner-span roof beam are respectively manufactured, concrete slurry is respectively poured into the grouting cavities of the inner-span floor beam and the inner-span roof beam, the inner-span floor beam and the inner-span roof beam are respectively formed after standing and curing, meanwhile, the exposed floor connecting longitudinal rib is wrapped by the inner-span roof beam, and the exposed roof connecting longitudinal rib is wrapped by the inner-span roof beam, so that the connection of a newly-built bare concrete cantilever structure of the existing building is completed.
Compared with the prior art, the beneficial effect of the connection of the existing building newly-increased bare concrete cantilever structure that this embodiment provided is the same basically as the beneficial effect of the existing building newly-increased bare concrete cantilever structure that embodiment one provided, and this is not repeated again.