Square steel tube steel fiber concrete column for boiler and column base joint

Abstract

The invention discloses a square steel tube steel fiber reinforced concrete column and a column base node for a boiler, the square steel tube steel fiber reinforced concrete column comprises a square steel tube steel fiber reinforced concrete column and a column base node, the square steel tube steel fiber reinforced concrete column comprises square steel, steel fiber reinforced concrete, a steel skeleton and prestressed tendons, the steel skeleton is coaxially arranged in the square steel, and the prestressed tendons are arranged in the steel skeleton. Steel fiber reinforced concrete is arranged in the square steel, the prestressed tendons are vertically arranged in gaps between the square steel and the steel framework, the column base joint comprises a bottom plate and foundation anchor bolts, and the foundation anchor bolts penetrate through and are connected with the bottom plate. The method has the beneficial effects that macroscopic cracks are dispersed into microcracks through the bridging effect of the steel fibers, and damage is delayed; the inclined steel bars bear shearing force, and development of concrete inclined cracks is slowed down; the steel framework increases the restraining effect on the concrete in the core area; through cooperation of the steel framework and the steel fiber reinforced concrete, the mechanical response of combining rigidity and softness is achieved, and a multiple reinforcement mechanism is formed through external constraint of the square steel pipes, internal constraint of the steel framework and active constraint of the prestressed tendons.

Description

Technical Field

[0001] The invention relates to the field of boiler structures, and in particular to a square steel tube steel fiber concrete column and a column foot node for a boiler. Background Art

[0002] In the boiler structure, the column is the core load-bearing component, which mainly bears the static weight of the boiler body and its ancillary equipment (such as water tanks, steam pipes, connectors, etc.), and is therefore subject to a large axial pressure. In addition, during the operation of the boiler, due to dynamic effects such as thermal expansion, wind loads or earthquakes, the column may also be subjected to lateral forces, thereby generating bending stress. This complex stress state requires the design of the column to meet the requirements of strength, stiffness and stability at the same time.

[0003] According to traditional steel structure design specifications, in order to ensure that the column can withstand the above loads and prevent instability, the wall thickness of the steel column usually needs to reach 30mm or even greater. However, although this design can meet safety requirements, it will lead to an increase in material consumption, thereby pushing up the production cost of the project. If the wall thickness is reduced to reduce costs, the column body may be locally unstable due to insufficient local strength, which will affect the stability and safety of the overall structure. Some engineers began to try to fill concrete into steel pipes to increase the strength of concrete by utilizing the restraining effect of steel pipes. Concrete can also prevent the steel pipe from buckling prematurely, but the bonding force between steel pipes and concrete is limited. Under long-term loads, the interface may slip, affecting the overall force performance and durability of the structure; in addition, the traditional design of the column is weak in seismic resistance and it is difficult to effectively respond to sudden loads such as earthquakes, further limiting its scope of application. Summary of the invention

[0004] The purpose of the present invention is to provide a square steel tube steel fiber concrete column and column base node for boilers to solve the above-mentioned technical problems of instability of the rod body when subjected to force, easy cracking of concrete, and insufficient restraint and seismic effect of the steel tube on the concrete.

[0005] In order to solve the above technical problems, the present invention provides a square steel tube steel fiber concrete column and a column base node for a boiler, which includes a square steel tube steel fiber concrete column and a column base node, the square steel tube steel fiber concrete column includes square steel, steel fiber concrete, a steel skeleton and prestressed tendons, the steel skeleton is coaxially arranged in the square steel, steel fiber concrete is arranged in the square steel, the prestressed tendons are vertically established in the gap between the square steel and the steel skeleton, and the column base node includes a base plate and an anchor bolt, and the anchor bolt passes through and connects the base plate.

[0006] Furthermore, the steel skeleton includes angle steels, flat steels, steel bars and steel bar hooks. The angle steels are vertically arranged equidistantly in a rectangular array. Flat steels are arranged equidistantly between adjacent angle steels along the height direction. The flat steels are connected to the outer sides of the angle steel flanges. Steel bars are obliquely arranged between adjacent flat steels along the height direction. The steel bars are connected to the outer sides of the angle steel flanges. Steel bar hooks are connected to the bottom of the angle steels.

[0007] Furthermore, the column base node also includes a stiffening rib, the bottom of the stiffening rib is connected to the base plate, and the side of the stiffening rib is connected to the square steel.

[0008] Furthermore, the column base node also includes shear nails, and the shear nails are connected to the square steel along the height direction.

[0009] Furthermore, the column base node also includes stirrups and anchoring steel bars, and the stirrups are tied to the anchoring steel bars at equal distances along the height direction.

[0010] Furthermore, the prestressed tendons are tensioned by a post-tensioning method.

[0011] Furthermore, the stiffening ribs are respectively welded to the bottom plate and the square steel through fillet welds.

[0012] Furthermore, bolt holes are provided on the bottom plate, and the bolt holes are used to pass through the ground anchor bolts.

[0013] The beneficial effects of the present invention are as follows: compared with the prior art, the square steel tube steel fiber concrete column and column foot node for boilers have the bridging effect of steel fibers that disperse macro cracks into micro cracks, delaying damage; the oblique steel bars bear shear forces, slowing down the development of oblique cracks in concrete; the steel skeleton increases the restraint on the concrete in the core area; in terms of structural selection and stress, square steel tubes are easier to match with the building plan layout than round steel tubes, and the cross-sectional bending stiffness of the rectangular steel tube concrete column is large, the node structure is simple, and the construction is more convenient.

[0014] The prestressed tendons provide self-resetting capabilities, and the ductility of steel fiber concrete delays collapse, forming a "damage-controllable" failure mode.

[0015] Through the coordination of steel skeleton and steel fiber concrete, a "rigid and flexible" mechanical response is achieved, and multiple reinforcement mechanisms are formed by external constraints of square steel tubes, internal constraints of steel skeleton, and active constraints of prestressed tendons.

[0016] While ensuring the bearing capacity, reduce the amount of structural steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of square steel tube steel fiber concrete column.

[0018] Figure 2 It is a schematic diagram of the top view of the square steel tube steel fiber concrete column structure.

[0019] Figure 3 It is a schematic diagram of the cross-sectional structure of square steel tube steel fiber concrete column.

[0020] Figure 4 It is a schematic diagram of the steel skeleton three-dimensional structure.

[0021] in:

[0022] 1. Square steel;

[0023] 2. Steel fiber concrete;

[0024] 3. Prestressed tendons;

[0025] 31. Pad;

[0026] 32. Anchorage;

[0027] 4. Steel frame;

[0028] 41. Angle steel;

[0029] 42. Flat steel;

[0030] 43. Steel bars;

[0031] 44. Steel bar hook;

[0032] 5. Column foot node;

[0033] 51. Anchor steel bars;

[0034] 52. Shear nails;

[0035] 53. Stirrups;

[0036] 54. Stiffening ribs;

[0037] 55. Bottom plate;

[0038] 56. Ground anchor bolts;

[0039] 57. Concrete at column base. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiment is only one embodiment of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0041] In order to make the objectives, technical solutions and advantages of the present application more clear, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0042] In the following description, references to "one embodiment", "an embodiment", "an example", "an example", etc. indicate that the embodiment or example described in this way may include specific features, structures, characteristics, properties, elements or limitations, but not every embodiment or example necessarily includes the specific features, structures, characteristics, properties, elements or limitations. In addition, repeated use of the phrase "according to one embodiment of the present application" may refer to the same embodiment, but does not necessarily refer to the same embodiment.

[0043] In this embodiment: Figure 1 As shown, it includes a square steel tube steel fiber concrete column and a column base node. The square steel tube steel fiber concrete column includes square steel 1, steel fiber concrete 2, steel skeleton 4 and prestressed tendons 3. The steel skeleton 4 is coaxially arranged in the square steel 1. The steel fiber concrete 2 is arranged in the square steel 1. The prestressed tendons 3 are vertically established in the gap between the square steel 1 and the steel skeleton 4. The column base node 5 includes a base plate 55 and a ground anchor bolt 56. The ground anchor bolt 56 penetrates and connects the base plate 55.

[0044] The steel skeleton 4 includes four equilateral angle steels 41, flat steels 42, steel bars 43 and steel bar hooks 44. The four angle steels 41 are equidistantly arranged vertically in a rectangular array. Flat steels 42 are equidistantly arranged between adjacent angle steels 41 along the height direction. The flat steels 42 are connected to the outer sides of the flanges of the angle steels 41. The connecting welds are fillet welds. Steel bars 43 are obliquely arranged between adjacent flat steels 42 along the height direction. The steel bars 43 are connected to the outer sides of the flanges of the angle steels 41. The bottom of the angle steels 41 is connected to the steel bar hooks 44. When pouring concrete for the foundation, sufficient space must be reserved for the steel bar hooks 44.

[0045] The column base node 5 also includes a stiffening rib 54, the bottom of the stiffening rib 54 is connected to the bottom plate 55, and the side of the stiffening rib 54 is connected to the square steel tube 1. The node is strengthened by the stiffening rib 54, and the stiffening rib 54 divides the square steel tube 1 into multiple small areas, reducing the effective length of the free deformation of the tube wall and significantly improving the ability to resist local buckling.

[0046] The column foot node 5 also includes a shear nail 52, which is connected to the square steel tube 1 along the height direction to transmit shear force and ensure that the two work together.

[0047] The column base node 5 also includes stirrups 53 and anchoring steel bars 51. The stirrups 53 are tied to the anchoring steel bars 51 at equal intervals along the height direction. The stirrups 53 and the anchoring steel bars 51 form a steel bar 43 skeleton, forming an overall force system, which can effectively resist shear force. Under the action of horizontal loads such as earthquakes, shear failure of the column base is prevented, the seismic performance of the structure is improved, the connection reliability of the column base node 5 and the upper structure is improved, and the overall stability of the structure is ensured.

[0048] The reserved space of the bottom steel bar hook 44 and the column foot concrete 57 are poured successively, and the prestressed tendon 3 is tensioned by the post-tensioning method. Before pouring the concrete, the core-pulling pipe is installed, and then the prestressed tendon 3 is inserted. The prestressed tendon 3 is fixed by the anchor 32 and the pad 31, and the anchor 32 is installed. Finally, the prestressed tendon 3 is tensioned.

[0049] The stiffening rib 54 and the bottom plate 55 are welded by fillet welds to constrain the deformation of the bottom plate 55 and avoid warping or cracking of the bottom plate 55 due to concentrated loads; the stiffening rib 54 and the square steel tube 1 are welded by fillet welds, which can significantly improve the anti-buckling capacity of the steel tube wall, especially when subjected to compression or bending, to prevent local instability of the tube wall. The bottom plate 55 and the bottom of the square steel tube 1 are welded by fillet welds.

[0050] Bolt holes are provided on the bottom plate 55, holes "for passing through" the tensioned prestressed tendons 3 are provided on the bottom plate 55, holes for the steel bar hooks 44 are provided on the bottom plate 55, and the bolt holes are used to pass through the anchor bolts 56. The anchor bolts 56 and the anchor steel bars 51 are embedded in the foundation to firmly connect the superstructure to the foundation, transfer the load and ensure the overall stability of the structure.

[0051] Workflow: During the foundation construction phase, first make the steel skeleton 4, arrange four equilateral angle steels 41 vertically in a rectangular array, weld flat steels 42 between adjacent angle steels 41 to form a transverse connection, and weld steel bars 43 obliquely along the height direction to enhance shear resistance. Weld steel bar hooks 44 at the bottom of the angle steels 41 and connect them to the embedded anchor steel bars 51 to ensure the stability of the steel skeleton 4.

[0052] Then, the anchor bolts 56 and the anchor steel bars 51 are embedded in advance; when pouring the foundation concrete, it is necessary to reserve installation space for the steel bar hook 44 to avoid collision between the hook and the concrete during subsequent construction;

[0053] After the square steel 1 is hoisted to the foundation, the bottom plate 55 is welded and fixed to the bottom of the square steel 1 tube by fillet welds, and stiffening ribs 54 are welded to the side walls of the square steel 1 to enhance local rigidity and anti-buckling capacity. After the steel frame 4 is installed into the square steel 1, the core-pulling pipe of the prestressed tendon 3 is then installed.

[0054] The first pouring of concrete, after the concrete curing is completed, the prestressed tendons 3 are inserted and the anchors 32 are installed. The post-tensioning method is used for symmetrical tensioning, and the tensioning force and elongation value are controlled. The steel fiber concrete 2 is poured in the square steel tube 1 and vibrated layer by layer to make it dense.

[0055] Then, the lower end of the vertical steel bar hook 44 is bent; and the second concrete pouring is performed;

[0056] During the construction of the column foot node 5, the bottom plate 55 is fixed to the foundation through the anchor bolts 56, and the column foot concrete 57 is poured to cover the anchor steel bar 51 and the bottom plate 55 to form an integral force transmission system. The stirrups 53 and the anchor steel bar 51 are tied to form a closed skeleton, and the shear nails 52 are welded along the height direction of the square steel tube 1 to enhance the bonding performance with the concrete, and finally the third concrete is poured. All welding parts need to be treated with anti-corrosion, and the weld quality, concrete density and prestressing records are checked during the final acceptance to ensure the safety and reliability of the structure.

[0057] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A square steel tube steel fiber concrete column and column foot node for a boiler, characterized in that: It includes a square steel tube steel fiber concrete column and a column base node. The square steel tube steel fiber concrete column includes square steel, steel fiber concrete, a steel frame and prestressed tendons. The steel frame is coaxially arranged in the square steel. Steel fiber concrete is arranged in the square steel. The prestressed tendons are vertically established in the gap between the square steel and the steel frame. The column base node includes a base plate and a ground anchor bolt. The ground anchor bolt passes through and connects the base plate.

2. A square steel tube steel fiber concrete column and column base node for a boiler according to claim 1, characterized in that: The steel skeleton includes angle steels, flat steels, steel bars and steel bar hooks. The angle steels are arranged vertically and equidistantly in a rectangular array. Flat steels are arranged equidistantly between adjacent angle steels along the height direction. The flat steels are connected to the outer sides of the angle steel flanges. Steel bars are obliquely arranged between adjacent flat steels along the height direction. The steel bars are connected to the outer sides of the angle steel flanges. Steel bar hooks are connected to the bottom of the angle steels.

3. A square steel tube steel fiber concrete column and column base node for a boiler according to claim 1, characterized in that: The column foot node also includes a stiffening rib, the bottom of the stiffening rib is connected to the bottom plate, and the side of the stiffening rib is connected to the square steel.

4. A square steel tube steel fiber concrete column and column base node for a boiler according to claim 1, characterized in that: The column foot node also includes shear nails, and the shear nails are connected to the square steel along the height direction.

5. The square steel tube steel fiber concrete column and column base node for boiler according to claim 1, characterized in that: The column base node also includes stirrups and anchoring steel bars, and the stirrups are tied to the anchoring steel bars at equal distances along the height direction.

6. A square steel tube steel fiber concrete column and column base node for a boiler according to claim 1, characterized in that: The prestressed tendons are tensioned by a post-tensioning method.

7. A square steel tube steel fiber concrete column and column base node for boiler according to claim 2, characterized in that: The stiffening ribs are respectively welded to the bottom plate and the square steel through fillet welds.

8. The square steel tube steel fiber concrete column and column base node for boiler according to claim 1, characterized in that: The bottom plate is provided with bolt holes, and the bolt holes are used to pass the ground anchor bolts.

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