CN103422617A - Continuous I beam adopting corrugated steel web steel and concrete composite structure - Google Patents

Abstract

The invention relates to an I-beam, and discloses a continuous I-beam with a corrugated steel web steel-concrete composite structure, which includes a corrugated steel web, an upper flange steel plate and a concrete composite structure, and a lower flange steel plate. The corrugated steel The web is arranged between the upper flange steel plate and the lower flange steel plate. The upper flange steel plate, the lower flange steel plate and the corrugated steel web are all connected by welding. One or more combination connections form a continuous beam structure, and the flange plate in the pressure-bearing area is combined with concrete to form a composite structure. The invention has the advantages of light structure, low steel consumption and good seismic performance. The corrugated steel web of the invention can realize the smooth transition between the straight line segment and the arc segment through the setting of three transition sections at the corner, and solve the stress concentration of the corner problems, especially the steel-concrete composite structure with micro-strain waves in the pressure-bearing parts, which has good structural performance and economy.

Description

Continuous I-beam with corrugated steel web steel-concrete composite structure

technical field

The invention relates to an I-beam, in particular to a continuous I-beam with corrugated steel web steel-concrete composite structure.

Background technique

For traditional I-beams or steel box girders, the height-to-thickness ratio of the web is generally about 100:1 according to the requirements of shear buckling resistance. The height-thickness ratio of the trapezoidal corrugated steel web can be Big 300:1. For the corrugated steel web used in the existing corrugated steel web I-beam, the corrugation of the web is composed of a straight line segment and an arc segment, and stress concentration is likely to occur at the connecting part of the straight line segment and the arc segment. Steel plates are also used for the compression flanges of traditional I-beams or steel box girders. The use of steel structures in the compression area cannot reflect the economy of steel structures. If steel-concrete composite structures are used, most of the compressive stress in the compression area will be borne by concrete. , although it can reflect the economy, but the shrinkage and creep characteristics of concrete make it unable to cooperate with the steel structure, resulting in stress redistribution.

Contents of the invention

The invention aims at the disadvantages of poor shear resistance of I-beams in the prior art, stress concentration easily occurs in the whole structure, and affects the service life of the structure. At the same time, pure steel is used as a pressure member, and the cost performance is low, especially the shrinkage and slowing of concrete in the combined structure. The variable characteristics make it unable to cooperate with the steel structure to bear the force, resulting in the phenomenon of stress redistribution. Provides a beam with high cross-section rigidity and high strength at the connection end. The web waveform is composed of three parts: a straight line section, a transition section, and an arc section. The transition section can effectively connect the straight line section and the arc section to solve the problem of straight line The problem of stress concentration when the section and the arc section are directly connected, and the use of concrete composite structure as the pressure-bearing frame, the continuous I-beam of corrugated steel web steel-concrete composite structure with good pressure performance and high cost performance. In particular, the pressure-bearing flange plate with micro-strain wave is adopted, and the corrugated steel web steel-concrete composite structure simply supported I-beam with concrete poured on the pressure flange plate solves the stress heavy caused by the shrinkage and creep of concrete. distribution phenomenon.

In order to solve the above technical problems, the present invention is solved through the following technical solutions:

The continuous I-beam with corrugated steel web steel-concrete composite structure includes a corrugated steel web, an upper flange steel plate and a concrete composite structure, and a lower flange steel plate. The corrugated steel web is arranged on the upper flange steel plate and the lower wing Between the flange steel plates, the upper flange steel plate and the corrugated steel web are connected by welding, and the corrugated steel web and the lower flange steel plate are connected by welding. The surface roughness of the upper and lower flange steel plates is 70-350 μm, and a single beam The solid structures are connected by one or more combinations of connecting ends or steel strands to form a continuous beam structure, and the flange plates in the pressure-bearing area are combined with concrete to form a composite structure. The flange plate in the pressure-bearing area is the upper flange steel plate or the lower flange steel plate. The flange plate in the pressure-bearing area is mainly the upper flange steel plate in the ordinary beam, and the lower flange steel plate in the cantilever beam.

Preferably, the corrugated steel web is a continuous trapezoidal corrugated steel plate with a transition section and an arc corner, the transition section is located between the straight section and the arc corner, the radius of the arc corner is r, and the radius of the transition section is R, R is the gradient radius, and R is ∞—r. The end of the transition section connected with the straight line section has a radius R which tends to infinity; the end of the transition section connected with the arc corner has a radius R which tends to be equal to r. Therefore, from the straight line section to the arc corner, the radius R of the transition section is from infinity Gradually decrease to be equal to r, so that the transition between the straight line segment and the arc corner is smoother, and the stress concentration is reduced. The waveform of the web is composed of three parts: straight line, transition and arc. The transition can effectively connect the straight line and the arc corner, and solve the problem of stress concentration when the straight line and the arc are directly connected. It is suitable for industrialization. Batch manufacturing, lower mold and manufacturing costs.

Preferably, the length of the line connecting the tangent points along the wave height direction of the corrugated steel web is L _AB , the length of the line connecting the tangent points along the wavelength direction is L _BC , and L _AB ≥ L _BC . The length of the line of tangent points along the wave height direction of the corrugated steel web is equal to or slightly greater than the length of the line of tangent points along the wavelength direction, that is, the design of L _AB ≥ L _BC makes the shear strength of the corrugated steel plate and the amount of steel used achieve a good cost performance , if the wavelength direction is too long, that is, L _BC ≥ _LAB , the shear resistance will be significantly reduced, and if the wavelength direction is too short, the steel consumption will increase significantly. Therefore, adopting the design of L _AB ≥ L _BC can not only ensure the shear strength, but also reduce the amount of steel as much as possible.

Preferably, the upper flange steel plate has miniature strain waves with convex peaks. The traditional corrugated steel plate basically has no longitudinal stiffness, but the flange plate with micro-strain waves has longitudinal stiffness and can withstand pressure, and the weakened longitudinal stiffness of the micro-strain wave part is reinforced by the convex section of the concrete.

Preferably, the height of the micro strain wave is 3-20 times the thickness of the upper flange steel plate, the peak length of the convex part is less than 300mm, and the distance between the peaks is greater than 1000mm. The wave height of the micro-strain wave is 3-20 times the thickness of the flange plate, which can reduce the compressive capacity of the flange plate due to the existence of the micro-strain wave when the flange plate is compressed, and increase the thickness of the flange plate by 3-20 times through the convex The increased concrete section is used to make up for it, so that the flange plate can not only accept the longitudinal shrinkage and creep of the concrete, and cooperate with the concrete to bear the force, but also maintain the overall structural strength during and after the longitudinal shrinkage and creep process.

Because the concrete is poured on the pressure flange, the concrete has short-term shrinkage and long-term creep. The above changes cause the concrete to shrink by about one-thousandth of the total amount, and the traditional straight flange combined with concrete cannot be coordinated. As a result, there is a significant difference between the actual stress state and the ideal stress state of the composite structure, and the flange plates that cannot shrink together take the lead in bearing the compressive stress, resulting in stress redistribution in the composite structure. This patent adopts the method of setting micro-strain waves on the straight flange plate, so that it can not only accept the longitudinal shrinkage and creep of concrete, but also maintain the structural strength during and after the longitudinal shrinkage and creep process, and solve the problem of composite structure in one fell swoop. The above bottleneck problem.

Preferably, the connection ends are welded connections.

Preferably, the welding connection of the connection ends adopts a simple support first, and then a continuous connection. The simple support first and then continuous connection method is due to the limitations of workshop manufacturing, transportation, hoisting length and other factors on the one hand, and on the other hand, this method is conducive to setting pre-camber or applying pre-stress between spans.

Preferably, the thickness of the upper flange steel plate is greater than or smaller than the thickness of the lower flange steel plate. Because the buckling needs to be considered in the compression area, buckling is not considered in the tension area, so the steel consumption or cross-sectional area of the traditional tension area and the compression area are the same, so that the parts in the tension area have redundant functions, which is unscientific and unscientific. Economical, the amount of steel used in the compression area is appropriately increased, which is conducive to the full play of the functions of the compression and tension parts of the component, and achieves a higher cost performance. When the thickness of the upper flange steel plate is greater than that of the lower flange steel plate, it is an ordinary I-beam, and the upper flange steel plate bears pressure; when the thickness of the upper flange steel plate is smaller than that of the lower flange steel plate, it is a cantilever beam, and the lower Flange steel plate under pressure.

Preferably, the upper and lower flange steel plates are arched along the wavelength direction of the corrugated steel web. Both the steel plate on the upper flange and the steel plate on the lower flange are arched, which is beneficial to the force of the component, offsets the deflection of the component under load, and improves the overall structural strength of the I-beam.

Preferably, in the upper flange steel plate and the lower flange steel plate, concrete is poured in the compressed area.

Due to the adoption of the above technical scheme, the present invention has remarkable technical effects: the present invention adopts corrugated steel plate as the web of the I-beam, which has the advantages of light structure, low steel consumption and good seismic performance, and the cross-sectional rigidity and The strength of the connection end is high, and the waveform of the web is composed of three parts: a straight line section, a transition section, and an arc section. The transition section can effectively connect the straight line section and the arc section, and solve the problem of stress concentration when the straight line section and the arc section are directly connected. The problem is that the concrete composite structure is used as the pressure-bearing frame, which has good pressure-bearing performance and high cost performance. In particular, the steel-concrete composite structure with micro-strain waves is used for the pressure-bearing parts, which solves the problem of stress redistribution in the composite structure, and enables the composite structure steel and concrete to be stressed synergistically, with good structural performance and economy.

Description of drawings

Fig. 1 is a schematic structural diagram of Embodiment 1 of the present invention.

Fig. 2 is a schematic diagram of the structure of the corrugated steel web in Fig. 1 .

Fig. 3 is an enlarged view of part I of Fig. 2 .

Fig. 4 is a left side view of Fig. 1 .

Figure 5 is a schematic diagram of the structure with micro-strain waves.

Fig. 6 is a front view of Fig. 5 .

The names of the parts indicated by the numbers in the above drawings are as follows: 1—upper flange steel plate, 2—corrugated steel web, 3—lower flange steel plate, 5—steel cable, 7—concrete, 11—miniature Strain wave, 21—arc corner, 22—transition section, 23—straight line section.

Detailed ways

Below in conjunction with accompanying drawing 1 to Fig. 6 and embodiment the present invention is described in further detail:

Example 1

The continuous I-beam with steel-concrete composite structure with corrugated steel web, as shown in Figures 1 to 6, includes a corrugated steel web 2, upper flange steel plate 1, concrete composite structure 7, and lower flange steel plate 3. The corrugated steel web 2 is arranged between the upper flange steel plate 1 and the lower flange steel plate 3, the upper flange steel plate 1 and the corrugated steel web 2 are connected by welding, and the corrugated steel web 2 and the lower flange steel plate 3 are connected by welding , the surface roughness of the upper flange steel plate 1 and the lower flange steel plate 3 is 70-350 μm, and the individual beam structures are connected by one or more combinations of connecting ends or steel ropes 5 to form a continuous beam structure, Flange plates in the pressure-bearing area are combined with concrete to form a composite structure. In the case of ordinary beams, the flange plate in the pressure-bearing area is the upper flange steel plate 1, and concrete 7 is poured on the upper flange steel plate 1. The surface roughness of the upper flange steel plate 1 and the lower flange steel plate 3 is 250 μm. High roughness can significantly increase the adhesion of the coating.

The corrugated steel web 2 is a continuous trapezoidal corrugated steel plate with a transition section 22 and an arc corner 21. The transition section 22 is located between the straight section 23 and the arc corner 21. The radius of the arc corner 21 is r, and the radius of the transition section 22 is R, R is the gradient radius, and R is ∞—r. One end that the transition section 22 is connected with the straight line section 23, the radius is that R is tending toward infinity; The radius R of 22 gradually decreases from infinity to equal to r, so that the transition between the straight line segment 23 and the arc corner 21 is smoother, and stress concentration is reduced. The waveform of the web is composed of three parts: straight line, transition and arc. The transition can effectively connect the straight line and the arc corner, and solve the problem of stress concentration when the straight line and the arc are directly connected. It is suitable for industrialization. Batch manufacturing, lower mold and manufacturing costs.

The length of the line connecting the tangent points along the wave height direction of the corrugated steel web 2 is L _AB , the length of the line connecting the tangent points along the wavelength direction is L _BC , and L _AB ≥ L _BC . The length of the line between the tangent points of the corrugated steel web 2 along the wave height direction is equal to or slightly greater than the length of the line between the tangent points along the wavelength direction, that is, the design of L _AB ≥ L _BC makes the shear strength and steel consumption of the corrugated steel plate reach a good balance Cost-effective, if the wavelength direction is too long, that is, L _BC ≥ _LAB , the shear resistance will be significantly reduced, and if the wavelength direction is too short, the steel consumption will increase significantly. Therefore, adopting the design of L _AB ≥ L _BC can not only ensure the shear strength, but also reduce the amount of steel as much as possible.

The upper flange steel plate has micro-strain waves 11 with convex crests. The wave height of the micro strain wave 11 is 3-20 times of the thickness of the upper flange steel plate, the peak length of the convex part is 250mm, and the distance between the wave peaks is 1200mm. The wave height of the micro-strain wave is 10 times the thickness of the flange plate, which can make the compressive capacity of the flange plate weakened due to the existence of the micro-strain wave when the flange plate is compressed. The cross-section is used to make up for the flange plate to not only accept the longitudinal shrinkage and creep of concrete, but also maintain the overall structural strength during and after the longitudinal shrinkage and creep process.

Ordinary straight flange plates have no stiffness in the longitudinal direction, and when the concrete shrinks and creeps, the steel plate hardly shrinks and creeps in the longitudinal direction. In this way, when the concrete shrinks and creeps, the flat flange plate and the concrete will peel off, and what is more serious is the stress redistribution problem that causes the steel structure to be the first to be stressed, which affects the stability of the structure and makes the structure Reduced strength.

The connection end is welded connection, and the welding connection of the connection end adopts the simple support first, and then the continuous connection method, forming a continuous structure, which can effectively prevent the beam from falling under the action of overloaded vehicles, heavy loads or earthquakes.

The thickness of the upper flange steel plate 1 is greater than or smaller than the thickness of the lower flange steel plate 3 . Because the buckling needs to be considered in the compression area, buckling is not considered in the tension area, so the steel consumption or cross-sectional area of the traditional tension area and the compression area are the same, so that the parts in the tension area have redundant functions, which is unscientific and unscientific. Economical, the amount of steel used in the compression area is appropriately increased, which is conducive to the full play of the functions of the compression and tension parts of the component, and achieves a higher cost performance. When the thickness of the upper flange steel plate 1 is greater than the thickness of the lower flange steel plate 3, it is an ordinary I-beam, and the upper flange steel plate 1 bears pressure; when the thickness of the upper flange steel plate 1 is smaller than the thickness of the lower flange steel plate 3, its As a cantilever beam, the lower flange steel plate 2 bears pressure.

The upper flange steel plate 1 and the lower flange steel plate 3 are arched along the wavelength direction of the corrugated steel web 2 . Both the upper flange steel plate 1 and the lower flange steel plate 3 are arched, which is conducive to the component stress, offsets the deflection of the component under load, and improves the overall structural strength of the I-beam.

In the upper flange steel plate 1 and the lower flange steel plate 2, concrete is poured in the compression area.

Example 2

As shown in Figures 1 to 6, the difference between this embodiment and Embodiment 1 is:

The upper flange steel plate has micro-strain waves 11 with convex crests. The wave height of the micro strain wave 11 is 3-20 times of the thickness of the upper flange steel plate, the peak length of the convex part is 200mm, and the distance between the wave peaks is 1500mm. The wave height of the micro-strain wave is 15 times the thickness of the flange plate, which can make the compressive capacity of the flange plate weakened due to the existence of the micro-strain wave when the flange plate is compressed. The cross-section is used to make up for the flange plate to not only accept the longitudinal shrinkage and creep of concrete, but also maintain the overall structural strength during and after the longitudinal shrinkage and creep process.

In a word, the above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the patent of the present invention.

Claims (10)

1. the continuous i beam of Wavelike steel webplate steel-concrete combined structure, comprise a Wavelike steel webplate (2), top flange steel plate (1) and concrete combined structure (7), bottom flange steel plate (3), it is characterized in that: described Wavelike steel webplate (2) is arranged between top flange steel plate (1) and bottom flange steel plate (3), top flange steel plate (1) and Wavelike steel webplate (2) are by being welded to connect, Wavelike steel webplate (2) and bottom flange steel plate (3) are by being welded to connect, top flange steel plate (1), bottom flange steel plate (3) surface roughness is 70-350 μ m, between single girder construction by one or more be connected in link or steel strand cable (5), form beam structure, the frange plate in pressure-bearing zone and Combined concrete form combining structure.

2. the continuous i beam of Wavelike steel webplate steel-concrete combined structure according to claim 1, it is characterized in that: described Wavelike steel webplate (2) is the continuous ladder twists and turns steel plate of band changeover portion (22) and circular arc-shaped corner (21), changeover portion (22) is positioned between straightway (23) and circular arc-shaped corner (21), circular arc-shaped corner (21) radius is r, the radius of changeover portion (22) is R, R is the gradual change radius, and R is ∞-r.

3. the continuous i beam of Wavelike steel webplate steel-concrete combined structure according to claim 1, it is characterized in that: described Wavelike steel webplate (2) is LAB along the point of contact wire length of wave height direction, along the point of contact wire length of wavelength direction, is L _BC, L _AB>=L _BC.

4. the continuous i beam of Wavelike steel webplate steel-concrete combined structure according to claim 1, it is characterized in that: described top flange steel plate (1) is with the miniature strain wave (11) of evagination crest.

5. the continuous i beam of Wavelike steel webplate steel-concrete combined structure according to claim 4, it is characterized in that: the 3-20 that the wave height of described miniature strain wave (11) is the top flange steel plate thickness doubly, the wave crest length of evagination part is less than 300mm, and the distance between crest and crest is for being greater than 1000mm.

6. the continuous i beam of Wavelike steel webplate steel work according to claim 1, it is characterized in that: described link is for being welded to connect.

7. the continuous i beam of Wavelike steel webplate steel work according to claim 6 is characterized in that: being welded to connect of described link adopts first freely-supported, rear continuous connected mode.

8. the continuous i beam of Wavelike steel webplate steel work according to claim 5, it is characterized in that: the thickness of described top flange steel plate (1) is greater than or less than the thickness of bottom flange steel plate (3).

9. the continuous i beam of Wavelike steel webplate steel work according to claim 1, it is characterized in that: described top flange steel plate (1), bottom flange steel plate (3) are arch along Wavelike steel webplate (2) wavelength direction.

10. the continuous i beam of Wavelike steel webplate steel-concrete combined structure according to claim 1 is characterized in that: in described top flange steel plate (1) and bottom flange steel plate (2), and the pressurized zone concreting.

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