Overhanging supporting device for super-long-span steel structure and supporting method of overhanging supporting device

Abstract

The invention relates to the technical field of overhanging supporting, in particular to a super-long-span steel structure overhanging supporting device and a supporting method thereof.The super-long-span steel structure overhanging supporting device comprises a building body and an I-shaped overhanging beam perpendicularly connected with the extending direction of the building body and further comprises a main stress unit and an auxiliary force transmission assembly; the main stress unit comprises two stress seats installed on a building body, one stress seat is connected with one end of the cantilever beam through a main force transmission assembly, the other stress seat is connected with a main inclined strut through a main force transmission assembly, the other end of the main inclined strut is connected with the bottom end of the cantilever beam, and the other end of the main inclined strut is connected with the bottom end of the cantilever beam. Through contact sliding connection of the wedge-shaped faces in the main force transmission assemblies, the cantilever beam has the capacity of freely sliding in the longitudinal direction under the action of temperature and loads, internal stress is released, and the cantilever beam meets the deformation requirement of the ultra-long span, meanwhile, the auxiliary force transmission assemblies arranged in a distributed and staggered mode are connected through elastic buffering connecting pieces of the auxiliary force transmission assemblies, and the deformation requirement of the ultra-long span is met. And the local bending moment of the key part of the cantilever beam can be actively shared.

Description

Technical Field

[0001] This invention relates to the field of cantilever support technology, and in particular to a cantilever support device and support method for ultra-long span steel structures. Background Technology

[0002] In the field of architectural engineering, ultra-long span steel cantilever structures utilize steel as the main load-bearing material and form a spatial skeleton through rigid connections (such as welding and bolted joints) to achieve roof or platform structures that extend horizontally outward over long distances without intermediate supports. Due to their high space utilization and flexible shapes, they are increasingly widely used in places such as stadium stands, airport boarding bridges, and cantilevered canopies in commercial complexes. However, the core technology of this type of structure lies in the connection and support system between the cantilever beam and the main building. On the one hand, the cantilever needs to bear the vertical loads such as the self-weight of the cantilever beam and the live load of the floor, and on the other hand, it needs to resist horizontal thrust such as wind and adapt to the deformation of the beam caused by temperature changes and load effects.

[0003] To alleviate the vertical load-bearing pressure of ultra-long cantilever beams, high-strength prestressed tie rods are typically installed on the lower chord side of the cantilever beam. One end of the tie rod is hinged to the end of the cantilever beam, and the other end is anchored to the building structure. Pre-stress is applied by tensioning the tie rod, generating tension to offset part of the vertical bending moment of the cantilever beam. However, after long-term use, the prestress of the tie rod is affected by environmental temperature fluctuations, such as thermal expansion and contraction causing changes in the tie rod length, and loosening of the anchorage, leading to a continuous decrease in load-bearing capacity. Furthermore, the tie rod needs to pass through end nodes. Simultaneously transmitting tension and additional bending moment generated by the cantilever beam, existing joints mostly adopt a hinged structure of "ear plate + pin": the ear plate is welded to the cantilever beam / building body, and the pin passes through the ear plate and the end of the tie rod to achieve rotational adaptation. However, there is an installation gap of 0.2 to 0.5 mm between the ear plate hole and the pin. Under the action of live load fluctuation or wind load, the gap will cause "impact collision between the pin and the ear plate". Long-term use will lead to wear and expansion of the ear plate hole, eventually resulting in loose joint and affecting the stability of force transmission.

[0004] Based on the above, we propose a cantilever support device and support method for ultra-long span steel structures to solve the above problems. Summary of the Invention

[0005] This invention provides a cantilever support device and support method for ultra-long span steel structures to solve the problems existing in the prior art.

[0006] The technical problem solved by this invention is achieved by the following technical solution:

[0007] A cantilever support device and method for ultra-long span steel structures includes a main building body and an I-shaped cantilever beam perpendicularly connected to the extension direction of the main building body. It also includes a main load-bearing unit and secondary force transmission components. The main load-bearing unit includes two load-bearing seats installed on the main building body. One load-bearing seat is connected to one end of the cantilever beam via the main force transmission component, and the other load-bearing seat is connected to a main diagonal brace via the main force transmission component. The other end of the main diagonal brace is connected to the bottom end of the cantilever beam. The secondary force transmission components are distributed on the upper and lower flanges of the cantilever beam. Each set of secondary force transmission components includes an "L"-shaped force transmission support member. The force transmission support has two sides corresponding to the flange and web of the cantilever beam, respectively. The elastic buffer connector is located between the force transmission support and the flange and web of the cantilever beam to share the bending moment of the cantilever beam. The main force transmission component includes a force transmission seat connected to the force-bearing seat, a wedge-shaped mounting groove opened on the force transmission seat, and a wedge-shaped mounting block located at one end of the cantilever beam and the main diagonal brace. The wedge-shaped mounting block and the wedge-shaped mounting groove form a surface contact type fitting and snap-fit. The wedge-shaped mounting block can slide controllably in the wedge-shaped mounting groove along the length direction of the cantilever beam to adapt to the temperature deformation and load deformation of the cantilever beam.

[0008] Preferably, the lower end of each cantilever beam is connected to multiple secondary diagonal braces, and the other end of each secondary diagonal brace is connected to the previous secondary diagonal brace located on the side closer to the main building.

[0009] Preferably, the main force transmission component is further provided with a limiting component, the limiting component including a limiting plate slidably connected to the force transmission base and a limiting hole opened on the force transmission base, and a limiting screw threadedly connected to the limiting plate.

[0010] Preferably, the flanges and web of the cantilever beam are connected to force-dispersing plates, which are connected to elastic buffer connectors. The force-dispersing plates, elastic buffer connectors, and force-transmitting supports are connected to the flanges and web of the cantilever beam by bolts.

[0011] Preferably, the force-dispersing plate and the cantilever beam are fully welded together, and the auxiliary force transmission components on both sides of the cantilever beam are staggered.

[0012] Preferably, the bottom of the wedge-shaped mounting block is provided with an extended pressing part, and the upper end of the extended pressing part is provided with a buffer pad. When the wedge-shaped mounting block is located inside the wedge-shaped mounting groove, the extended pressing part abuts against the bottom of the force transmission seat.

[0013] Preferably, the load-bearing seat is connected to a connecting steel bar, and the connecting steel bar is cast inside the main body of the building.

[0014] A method for supporting an ultra-long span steel structure cantilever support device includes the following steps:

[0015] S1. Pre-embedded load-bearing seats: The two load-bearing seats of the main load-bearing unit are pre-embedded in the main building structure by connecting steel bars and then cast and fixed.

[0016] S2. Main structure installation: Slide one end of the cantilever beam and one end of the main diagonal brace into the wedge-shaped mounting slot of the corresponding force-bearing seat along the length of the cantilever beam through the wedge-shaped mounting block on them, so as to achieve surface contact adaptation and snap-fit, and complete the connection between the other end of the main diagonal brace and the bottom end of the cantilever beam.

[0017] S3. Installation of secondary force transmission components: Install force distribution plates on the flanges and webs of the cantilever beam, and then install the two sides of the force transmission support on the flanges and webs of the cantilever beam respectively through elastic buffer connectors to share the bending moment of the cantilever beam.

[0018] In step S2, the wedge-shaped mounting block is allowed to slide controllably within the wedge-shaped mounting groove along the length of the cantilever beam to accommodate the deformation of the cantilever beam caused by temperature and load changes during use.

[0019] Preferably, after step S2, the installation of secondary bracing is also included, wherein multiple secondary bracings are installed at the lower end of the cantilever beam, and the other end of each secondary bracing is connected to the previous secondary bracing on the side closer to the main building.

[0020] The beneficial effects of this invention are as follows: through the wedge-shaped surface contact sliding connection in the main force transmission component, the cantilever beam is able to slide freely in the longitudinal direction under the action of temperature and load, releasing internal stress and adapting to the deformation requirements of ultra-long span. At the same time, the distributed staggered arrangement of the secondary force transmission components can actively share the local bending moment of the key parts of the cantilever beam through its elastic buffer connectors, and suppress fatigue vibration caused by load, thereby improving the durability of the structure. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the isometric structure provided by the present invention;

[0023] Figure 2 This is a partial cross-sectional structural schematic diagram provided by the present invention;

[0024] Figure 3 This invention provides a schematic diagram of the wedge-shaped mounting block separating from the wedge-shaped mounting groove.

[0025] Figure 4 This is a schematic diagram of the secondary force transmission component in this invention;

[0026] Figure 5 This is a schematic diagram of the process in this invention.

[0027] In the diagram, 1. Main building structure; 2. Cantilever beam; 3. Load-bearing seat; 4. Main diagonal brace; 5. Force transmission support component; 6. Elastic buffer connector; 7. Force transmission seat; 8. Wedge-shaped mounting groove; 9. Wedge-shaped mounting block; 10. Secondary diagonal brace; 11. Limiting plate; 12. Limiting hole; 13. Limiting screw; 14. Force dispersing plate; 15. Extended pressure part; 16. Buffer pad; 17. Connecting steel bar. Detailed Implementation

[0028] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific illustrations.

[0029] Reference Figures 1-5 As shown, an ultra-long span steel structure cantilever support device includes a building body 1, an I-shaped cantilever beam 2, a main load-bearing unit, and a secondary load-transmitting component. The I-shaped cantilever beam 2 can be made of Q355B steel, and its cross-sectional dimensions are determined by calculation. The cantilever length can reach more than 30 meters, and its extension direction is perpendicular to the building body 1. The main load-bearing unit includes two load-bearing seats 3 fixed to the outside of the building body 1 by high-strength anchor bolts. A more preferred option is that connecting steel bars 17 are welded on the load-bearing seats 3. During the civil construction stage, the connecting steel bars 17 are poured into the concrete of the building body 1, and the ends of the connecting steel bars 17 can be provided with elbows, thereby achieving a more reliable and rigid connection.

[0030] Two load-bearing seats 3 are distributed vertically. One of them, the upper load-bearing seat 3, is connected to the root end of the cantilever beam 2, that is, the end closest to the main building 1, through a main force transmission component. The other load-bearing seat 3, the lower one, is connected to a main diagonal brace 4 through another set of main force transmission components. The main diagonal brace 4 is made of box-section or I-section steel, and its other end is fixedly connected to the bottom end of the cantilever beam 2. The main diagonal brace 4, the cantilever beam 2, and the main building 1 together form a stable triangular main force transmission system, which effectively transfers most of the vertical load borne by the cantilever beam 2 to the main building 1.

[0031] The main force transmission component is one of the core innovations of this project. Specifically, the main force transmission component includes a force transmission seat 7 fixed to the force-bearing seat 3 by bolts, a wedge-shaped mounting groove 8 opened on the force transmission seat 7, and a wedge-shaped mounting block 9 welded and fixed to the ends of the cantilever beam 2 (and the ends of the main diagonal brace 4). The inclined angle of the wedge-shaped mounting block 9 is completely consistent with the inclined angle of the wedge-shaped mounting groove 8, forming a large-area surface contact adapter snap-fit. Compared with the traditional pin-shaft hinge connection, this surface contact force transmission mode greatly increases the bearing area, avoids stress concentration, and improves the force transmission efficiency. It has higher stability and the wedge-shaped mounting block 9 can slide controllably in the wedge-shaped mounting groove 8 along the length of the cantilever beam 2. This design is intended to adapt to the longitudinal deformation and displacement of the cantilever beam 2 caused by changes in ambient temperature (thermal expansion and contraction) and changes in live load (such as crowd gathering and evacuation). When the cantilever beam 2 extends or shortens, the sliding of the wedge-shaped mounting block 9 can release the huge temperature stress and deformation stress generated thereby, preventing the structure from being damaged due to deformation restriction. During installation, the cantilever beam 2 and the main diagonal brace 4 can be inserted from one side opening of the wedge-shaped mounting groove 8.

[0032] Reference Figure 3 As shown, the main force transmission assembly is further provided with a limiting assembly, which includes a limiting plate 11 slidably connected to the force transmission base 7 and a limiting hole 12 opened on the force transmission base 7. A limiting screw 13 is threadedly connected to the limiting plate 11. When the wedge-shaped mounting block 9 is installed into the wedge-shaped mounting groove 8, the limiting plate 11 is slid to one side of the wedge-shaped mounting groove 8 to seal it, and the limiting plate 11 is locked by screwing the limiting screw 13 into the limiting hole 12 to prevent the wedge-shaped mounting block 9 from moving out of the wedge-shaped mounting groove 8.

[0033] Among them, reference Figure 3 As shown, to further optimize the force distribution and buffer the sliding impact, the bottom of the wedge-shaped mounting block 9 extends downward to form an extended pressing part 15. The upper surface of the extended pressing part 15 is attached with a buffer pad 16, which can be made of polyurethane elastomer. When the wedge-shaped mounting block 9 is installed in place, the extended pressing part 15 abuts against the bottom of the force transmission seat 7, and the buffer pad 16 is slightly compressed. This is equivalent to providing an elastic support in the force transmission path, which can effectively absorb and buffer the small vibrations and impacts from the cantilever beam 2.

[0034] The secondary force transmission component 4 is another core innovation of this solution. Multiple sets are distributed and anchored to the upper and lower flanges of the cantilever beam 2. Each secondary force transmission component includes an "L"-shaped force transmission support 5 and an elastic buffer connector 6. The elastic buffer connector 6 is constructed using multiple sets of butterfly springs. Before installing the secondary force transmission components, the force dispersion plate 14 is first fully welded to the predetermined positions on the flanges and web of the cantilever beam 2. Full welding ensures that the load is evenly transferred from the parent material to the force dispersion plate 14, avoiding stress concentration. Then, the elastic buffer connector 6 is attached to the force dispersion plate 14. Finally, one side of the L-shaped force transmission support 5 is connected to the force dispersion plate 14 and the elastic buffer connector on the upper (or lower) flange using high-strength bolts. The connecting piece 6 connects the other side to the force distribution plate 14 of the web and the elastic buffer connecting piece 6 via high-strength bolts. All the secondary force transmission components located on both sides of the cantilever beam 2 are staggered to avoid excessive weakening of the beam at the same section, further ensuring the overall strength of the cantilever beam 2. When the cantilever beam 2 undergoes flexural deformation, its flange and web will generate local bending moments and stresses. The force transmission support piece 5 is connected to the beam through the elastic buffer connecting piece 6, forcing the deformation of this part to be transmitted and distributed through the compression and shear of the elastic buffer connecting piece 6, thereby reducing the peak bending moment of the cantilever beam 2. At the same time, the elastic buffer connecting piece 6 can continuously absorb the energy generated by dynamic loads such as wind vibration and human-induced vibration, greatly improving the fatigue performance of the structure.

[0035] Among them, multiple secondary diagonal braces 10 are connected to the lower end of the cantilever beam 2. The secondary diagonal braces 10 can be made of the same material as the main diagonal braces 4, such as I-beams. The upper end of each secondary diagonal brace 10 is connected to the node plate of the lower flange of the cantilever beam 2, and its other end is connected to the middle of the previous secondary diagonal brace 10 located on the side closer to the main building 1, thus forming a secondary, mesh-like auxiliary force transmission system, which works in conjunction with the main diagonal braces 4 to jointly constrain the vertical deformation of the cantilever beam 2.

[0036] Furthermore, an ultra-long span steel structure cantilever support device also includes the following support methods:

[0037] S1, Pre-embedded load-bearing seat 3: The two load-bearing seats 3 of the main load-bearing unit are pre-embedded and cast into the main body 1 of the building through connecting steel bars 17 to form a permanent connection;

[0038] S2. Main structure installation: After the main structure reaches the required strength, slide one end of the cantilever beam 2 and one end of the main diagonal brace 4 into the wedge-shaped mounting groove 8 of the corresponding force-bearing seat 7 along the length of the cantilever beam 2 through the wedge-shaped mounting block 9 on them, so as to achieve surface contact type fitting and connection, and complete the connection between the other end of the main diagonal brace 4 and the bottom end of the cantilever beam 2.

[0039] S3. Installation of secondary force transmission components: Install force dispersion plates 14 on the flanges and webs of the cantilever beam 2. Then, install the two sides of the force transmission support 5 on the flanges and webs of the cantilever beam 2 respectively through the elastic buffer connector 6. Tighten the high-strength bolts to the design preload using a torque wrench to share the bending moment of the cantilever beam 2.

[0040] In step S2, the wedge-shaped mounting block 9 is allowed to slide controllably within the wedge-shaped mounting groove 8 along the length of the cantilever beam 2 to accommodate the deformation of the cantilever beam 2 caused by temperature and load changes during use.

[0041] Reference Figures 1-5 As shown, further, after step S2, the installation of the secondary diagonal braces 10 is also included from the direction close to the main building 1 to the direction away from the main building 1. Multiple secondary diagonal braces 10 are installed at the lower end of the cantilever beam 2, and the other end of each secondary diagonal brace 10 is connected to the previous secondary diagonal brace 10 on its side close to the main building 1.

[0042] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A cantilever support device for an ultra-long span steel structure, comprising a main building (1) and an I-shaped cantilever beam (2) perpendicularly connected to the extension direction of the main building (1), characterized in that, Also includes; The main load-bearing unit includes two load-bearing seats (3) installed on the main body of the building (1). One of the load-bearing seats (3) is connected to one end of the cantilever beam (2) through a main force transmission component. The other load-bearing seat (3) is connected to a main diagonal brace (4) through the main force transmission component. The other end of the main diagonal brace (4) is connected to the bottom end of the cantilever beam (2). The secondary force transmission components are distributed on the upper and lower flanges of the cantilever beam (2). Each set of the secondary force transmission components includes an "L"-shaped force transmission support (5) and an elastic buffer connector (6). The two sides of the force transmission support (5) correspond to the flange and web of the cantilever beam (2) respectively. The elastic buffer connector (6) is located between the force transmission support (5) and the flange and web of the cantilever beam (2) to share the bending moment of the cantilever beam (2). The main force transmission component includes a force transmission seat (7) connected to the force-bearing seat (3), a wedge-shaped mounting groove (8) opened on the force transmission seat (7), and a wedge-shaped mounting block (9) located at one end of the cantilever beam (2) and the main diagonal brace (4). The wedge-shaped mounting block (9) and the wedge-shaped mounting groove (8) form a surface contact type fitting and snap-fit ​​connection, and the wedge-shaped mounting block (9) can slide controllably in the wedge-shaped mounting groove (8) along the length direction of the cantilever beam (2) to adapt to the temperature deformation and load deformation of the cantilever beam (2).

2. The cantilever support device for ultra-long span steel structures according to claim 1, characterized in that, The lower end of each cantilever beam (2) is connected to a plurality of secondary diagonal braces (10), and the other end of each secondary diagonal brace (10) is connected to the previous secondary diagonal brace (10) located on the side closer to the main building (1).

3. The cantilever support device for ultra-long span steel structures according to claim 1, characterized in that, The main force transmission component is also provided with a limiting component, which includes a limiting plate (11) slidably connected to the force transmission base (7) and a limiting hole (12) opened on the force transmission base (7). A limiting screw (13) is threadedly connected to the limiting plate (11).

4. The cantilever support device for ultra-long span steel structures according to claim 1, characterized in that, The flange and web of the cantilever beam (2) are connected to a force-dispersing plate (14), which is connected to the elastic buffer connector (6). The force-dispersing plate (14), the elastic buffer connector (6) and the force transmission support (5) are connected by bolts on the flange and web of the cantilever beam (2).

5. The cantilever support device for ultra-long span steel structures according to claim 1, characterized in that, The force-dispersing plate (14) and the cantilever beam (2) are connected by full welding, and the auxiliary force transmission components on both sides of the cantilever beam (2) are staggered.

6. The cantilever support device for ultra-long span steel structures according to claim 1, characterized in that, The bottom of the wedge-shaped mounting block (9) is provided with an extended pressing part (15), and the upper end of the extended pressing part (15) is provided with a buffer pad (16). When the wedge-shaped mounting block (9) is located inside the wedge-shaped mounting groove (8), the extended pressing part (15) abuts against the bottom of the force transmission seat (7).

7. The cantilever support device for ultra-long span steel structures according to claim 1, characterized in that, The load-bearing seat (3) is connected to a connecting steel bar (17), and the connecting steel bar (17) is cast inside the main body of the building (1).

8. A support method for an ultra-long span steel structure cantilever support device according to any one of claims 1-7, characterized in that, Includes the following steps: S1, Force-bearing seat (3) pre-embedded: The two force-bearing seats (3) of the main force-bearing unit are pre-embedded and cast and fixed in the main body (1) of the building through connecting steel bars (17); S2. Main structure installation: One end of the cantilever beam (2) and one end of the main diagonal brace (4) are respectively slid into the wedge-shaped mounting groove (8) of the corresponding force-bearing seat (7) along the length direction of the cantilever beam (2) through the wedge-shaped mounting block (9) on it, so as to achieve surface contact type fitting and connection, and complete the connection between the other end of the main diagonal brace (4) and the bottom end of the cantilever beam (2); S3. Installation of secondary force transmission components: Install force distribution plates (14) on the flanges and webs of the cantilever beam (2), and then install the two sides of the force transmission support (5) on the flanges and webs of the cantilever beam (2) respectively through the elastic buffer connector (6) to share the bending moment of the cantilever beam (2). In step S2, the wedge-shaped mounting block (9) is allowed to slide controllably within the wedge-shaped mounting groove (8) along the length of the cantilever beam (2) to accommodate the deformation of the cantilever beam (2) caused by temperature and load changes during use.

9. The support method for an ultra-long span steel structure cantilever support device according to claim 8, characterized in that, Following step S2, the installation of secondary bracing (10) is also included, with multiple secondary bracing (10) installed at the lower end of the cantilever beam (2), and the other end of each secondary bracing (10) connected to the previous secondary bracing (10) on the side closer to the main building (1).

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