CN103061453B - Double-perforated steel plate-concrete combined coupling beam - Google Patents

Abstract

The invention discloses a double-perforated steel plate-concrete combined coupling beam comprising a concrete beam, and a reinforcement framework arranged in the concrete beam and formed by longitudinal reinforcements, waist reinforcements and stirrups horizontally wound around the longitudinal reinforcements and the waist reinforcements, a reinforced concrete coupling beam is formed by the concrete beam and the reinforcement framework, a section steel framework including the double perforated steel plates are arranged in the reinforced concrete coupling beam, and a combined coupling beam is formed by the reinforced concrete coupling beam and the section steel framework; and the section steel framework is composed of a pair of perforated steel plates distributed symmetrically, a binding bar connecting the pair of perforated steel plates and shear-resistant studs vertically and uniformly distributed on the pair of perforated steel plates, and the pair of perforated steel plates is provided with holes respectively. According to the double-perforated steel plate-concrete combined coupling beam, the resistance moment is jointly resisted by the reinforced concrete and the perforated steel plates, the good bearing capacity and the plastic deformation capacity of the steel plates are utilized for resisting shearing, and an energy dissipation mechanism is achieved by the holes so that the bonding of the steel and the concrete is strengthened; and therefore, the shear capacity and the ductility and energy dissipation capacity of the coupling beam are obviously improved, and consequently the seismic performance of the coupling beam is greatly improved.

Description

An open-hole double steel plate-concrete composite coupling beam

technical field

The invention relates to a steel and concrete composite structure and a composite connecting beam of a mixed structure, in particular to a steel-concrete composite connecting beam, that is, a double steel plate-concrete composite connecting beam with openings.

Background technique

Coupling beams are the key components in the shear wall or core tube structural system of high-rise buildings. They have always been the key components studied by civil engineering scholars at home and abroad. At present, a lot of research work has been done on reinforced concrete coupling beams. By improving the reinforcement form and material composition of coupling beams, improving the shear bearing capacity of components and improving the ductility of coupling beams has become one of the main directions of coupling beam research. In recent years, the vast majority of structures in my country still use reinforced concrete coupling beams, but studies have shown that under various new reinforcement schemes, although the comprehensive seismic performance of reinforced concrete coupling beams has improved, there is still insufficient shear resistance. The damage is serious, and the hysteretic curve has obvious pinching effect. It is limited to improve the ductility and shear capacity of the coupling beam only by increasing the amount of stirrups and the form of reinforcement. In view of the existing problems of reinforced concrete coupling beams, in order to improve the mechanical performance and seismic performance, researchers proposed to use steel-concrete composite coupling beams instead of reinforced reinforced concrete coupling beams. Steel-concrete composite coupling beams have good ductility and Energy-dissipating capacity, suitable for earthquake zone for strong earthquake fortification. However, the current combination form of steel-concrete composite coupling beams is still relatively simple, and there are disadvantages such as complex structure, difficult construction, poor economy, and the slippage between steel and concrete reduces the bearing capacity and energy dissipation capacity of coupling beams. Therefore, To explore a new type of coupling beam combination with better seismic performance and more convenient construction, so that it can give full play to the respective properties of steel and concrete, has become an urgent problem to be solved when applying steel-concrete composite coupling beams in high-rise buildings and areas with high seismic intensity.

Contents of the invention

The technical problem to be solved by the present invention is to provide a new cross-section steel-concrete composite coupling beam, that is, open-hole double steel plate-concrete composite coupling beam, which overcomes the disadvantages of poor ductility and energy dissipation capacity of traditional reinforced concrete coupling beams, thereby greatly Improve the seismic performance of the coupling beam.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

An open-hole double-steel plate-concrete composite connecting beam, including a concrete beam, and a steel frame formed by longitudinal steel bars, waist bars, and stirrups horizontally surrounding the longitudinal steel bars and waist bars arranged in the concrete beam, the concrete beam and the steel bar The frame constitutes a reinforced concrete connecting beam, and the reinforced concrete connecting beam is provided with a section steel frame including double steel plates with openings, and the reinforced concrete connecting beam and the section steel frame form a combined connecting beam; the section steel frame is composed of a pair of opening steel plates symmetrically distributed 1. Constraint tie rods connecting the pair of perforated steel plates and shear studs arranged vertically and evenly on the surface of the pair of perforated steel plates, the pair of perforated steel plates are respectively provided with perforated holes.

Further, the openings of the perforated steel plates placed in the reinforced concrete connecting beams are distributed symmetrically up and down along the perforated steel plates, and the perforated openings are double-row circular or double-row rectangular.

Further, the horizontally surrounded stirrups along the longitudinal steel bars are correspondingly connected with double rows of symmetrically distributed openings.

Further, the shear studs arranged vertically and evenly on the surface of the perforated steel plate are distributed along the surface of the perforated steel plate.

Further, the constraint tie rods connected to the perforated steel plates are evenly distributed along the periphery of the perforated openings distributed on the perforated steel plates.

Further, the restraining rod is a screw-type structure or a panel-type structure.

Further, the distance between the centers of the pair of perforated steel plates is 1/6 to 2/3 of the cross-sectional width of the combined connecting beam.

Further, the height of the perforated steel plate is not less than 70% of the section height of the connecting beam, and the aspect ratio of the perforated steel plate is not greater than 100.

Further, the section steel ratio of the composite connecting beam is not less than 2.0%.

Further, the opening ratio of the openings on the perforated steel plate is 5%-20%.

The beneficial effects of the present invention are:

The open-hole double steel plate-concrete composite connecting beam is composed of reinforced concrete and open-hole steel plates to resist the bending moment, and utilizes the good bearing capacity and plastic deformation capacity of the steel plates to resist shearing. Different forms of holes are opened on the steel plates to realize the energy dissipation mechanism , at the same time strengthen the bond between steel and concrete, form a combination of concrete studs and shear studs to ensure the joint action of steel plates and concrete, prevent brittle failure of the coupling beam, and significantly improve the shear bearing capacity and ductility consumption of the coupling beam ability, thereby greatly improving the seismic performance of ordinary reinforced concrete coupling beams. Compared with the cross-reinforced coupling beam, the open-hole double steel plate-concrete composite coupling beam has a simpler structure, eliminating the structural difficulties and complex construction caused by the cross-reinforcement; Compared with the concrete coupling beam, because the steel plate is a planar element, it eliminates the structural difficulties that occur when other steel beams are connected to the wall pier. The upper perforation greatly facilitates the construction.

Under the action of large earthquakes, the confinement effect of concrete on the built-in steel plates has greatly weakened the problems that single-layer steel plates are more prone to buckling and instability under repeated loads, and the use of high-strength concrete is limited. Double steel plates are built in reinforced concrete connecting beams. The two steel plates are formed into a whole by restraining tie rods, which increases the restraint ability of the steel plate to the core concrete, and uses shear studs to reduce the slippage between the steel plate and the concrete, and improves the cooperative ability of the steel plate and the surrounding concrete, thus significantly Improved the seismic performance of the coupling beam. When the restraint rods are connected by threaded restraint rods, and when the shear studs are welded to the steel plate, the combination of bolt connection and welding can reduce the influence of welding residual stress, and at the same time significantly reduce the thickness of the steel plate, save or a large number of Reduce the welding process and reduce the engineering cost.

The invention absorbs the advantages of the reinforced concrete connecting beam and the steel concrete connecting beam, and the outsourcing concrete solves the fire prevention problem of the steel beam, and the lateral restraint effect of the concrete can effectively prevent the out-of-plane instability of the steel plate. By adjusting the parameters such as the aspect ratio of the steel plate, the size of the opening ratio, the size and spacing of the restraining rods and the pegs, different design requirements can be met, and it has great flexibility and adaptability. This kind of perforated double-steel plate-concrete composite connecting beam can be popularized and applied in high-rise buildings and buildings in areas with high seismic intensity, especially high-rise buildings in areas with seismic fortification intensity above 8 degrees.

Description of drawings

Fig. 1 is the schematic cross-sectional view of the double steel plate-concrete composite connecting beam with openings;

Fig. 2 is a structural schematic diagram of embodiment 1 of the opening double steel plate-concrete composite coupling beam with steel and reinforcement.

Fig. 3 is a structural schematic diagram of Embodiment 2 of steel and reinforcement reinforcement for double-steel plate-concrete composite coupling beams with openings.

In the figure: 1 is the perforated steel plate, 2 is the restraining rod, 3 is the shear stud, 4 is the longitudinal reinforcement, 5 is the stirrup, 6 is the waist bar, and 7 is the opening of the hole.

Detailed ways

The present invention will be further described below in conjunction with specific examples and accompanying drawings. It should be noted that the following examples are limited to explain the present invention, but do not limit the implementation scope of the present invention. All structural additions made on the basis of this scheme or replacements with the same content shall belong to the protection scope of the present invention.

As shown in Figure 1, the open-hole double-steel plate-concrete composite connecting beam includes a concrete beam and a stirrup 5 arranged horizontally in the concrete beam by a longitudinal steel bar 4, a waist bar 6, and horizontally surrounded by a longitudinal steel bar 4 and a waist bar 6 The formed steel frame is composed of concrete beams and steel frames to form reinforced concrete connecting beams, wherein: the reinforced concrete connecting beams are provided with a section steel frame including double steel plates with openings, and the reinforced concrete connecting beams and section steel frames form a composite coupling beam, and the section steel frame It consists of a pair of parallel and symmetrically distributed perforated steel plates 1, a restraining rod 2 connecting the pair of perforated steel plates 1, and shear studs 3 arranged vertically and uniformly along the surface of the pair of perforated steel plates 1. A pair of perforated steel plates The steel plates 1 are respectively provided with openings 7 .

As shown in Figure 2, the holes 7 of a pair of perforated steel plates 1 placed in the reinforced concrete connecting beam are distributed symmetrically along the upper and lower rows of the perforated steel plates 1, and the perforated holes 7 are double-row circular; It can be seen that the stirrups 5 horizontally surrounded by the longitudinal steel bars 4 are correspondingly connected with the openings 7 distributed symmetrically in double rows; In addition, the restraining rods 2 connected to the perforated steel plate 1 are evenly distributed along the periphery of the perforated openings 7 distributed on the perforated steel plate 1, and the restraining rods 2 are threaded or patched. The panel structure is composed of several stiffeners welded symmetrically on both sides of the steel plate, and the stiffeners are welded by small rectangular thin steel panels.

As shown in Figure 1, the steel frame embedded in the reinforced concrete connecting beam adopts double steel plates 1 with openings, and a pair of steel plates with openings connected by shear studs 3 and restraint rods 2, longitudinal steel bars 4, waist bars 6 and quadrilateral The space integral steel frame formed by the stirrups 5 constrains the core concrete and works together with it to ensure the bearing capacity and seismic performance of the steel plate-concrete composite coupling beam.

The double-steel plates with holes in the restraint rods of the present invention are designed as an integrated structure, that is, a pair of double-steel plates 1 with holes are connected by restraint rods 2, and the shear studs 3 are welded on the steel plates 1, wherein the double-steel plates with holes-concrete composite connecting beams are matched with steel And reinforcement shown in Figure 2.

Fig. 3 shows another kind of embodiment of the present invention, and its structure is basically the same as embodiment 1, and the difference is that the perforated hole 7 is a double row rectangular structure, in this structure, along the longitudinal steel bar 4 horizontally surrounded The stirrups 5 correspond to the upper, middle and lower parts of the double-row rectangles in the double-row symmetrically distributed openings 7 .

The present invention overcomes the problem by using the perforated double-steel plate-concrete composite coupling beam consisting of the above-mentioned perforated double-steel plates, constraining tie rods (including threaded constrained tie rods or embossed plates), longitudinal steel bars, stirrups, waist bars, and shear studs. The shortcomings of traditional reinforced concrete coupling beams, such as poor ductility and energy dissipation capacity, can enhance the seismic performance and constructability of coupling beams. Utilize the finite element method to carry out the comparison and analysis of the anti-seismic performance of the ordinary diagonal inclined steel connecting beam and the double steel plate-concrete composite connecting beam of the present invention, the result shows that the double steel plate-concrete composite connecting beam with the opening has a larger deformation Capacity and ductility coefficient, the hysteresis curve is plump, showing strong shock resistance and energy absorption capacity.

In order to ensure sufficient bearing capacity and seismic performance, the distance between the centers of a pair of perforated steel plates is 1/6 to 2/3 of the width of the composite connecting beam section, and the height of the perforated steel plates should not be less than 70% of the height of the connecting beam section. The height-to-thickness ratio of the steel plate is not greater than 100, and the opening ratio of the perforated steel plate is preferably 5% to 20%. The steel ratio of the composite coupling beam should not be too low or too high, too few perforated steel plates will fail to achieve the purpose, but too many perforated steel plates will increase the project cost. Combined with the experimental research and my country's national conditions, the optimum steel ratio for the section of the perforated double steel plate-concrete composite coupling beam in this embodiment is 7.0%, the optimum perforation rate for the perforated hole 7 is 12%, and the center of a pair of perforated steel plates The distance is preferably 1/3 of the section width of the composite coupling beam. When the span-to-height ratio of the coupling beam is 2.5, the energy dissipation ratio and ductility coefficient of the double-steel plate-concrete composite coupling beam with openings within a certain range of steel distribution ratio and opening ratio are higher than those of the ordinary beam with the same section size and span-to-height ratio. The connecting beams with diagonal reinforcements are increased by 51.99% and 82.86% respectively.

The following table 1 shows the comparison of the seismic performance between the present invention and common diagonally inclined reinforced beams.

Table 1 Comparison of energy consumption ratio and ductility coefficient between the present invention and common diagonal inclined reinforcement beams

In order to better ensure that the steel plate and concrete work together, it is absolutely necessary and effective to configure a certain number of shear studs, longitudinal reinforcement, waist bars and stirrups in the section of the open-hole double steel plate-concrete composite coupling beam. In the completed test, a certain number of shear studs were arranged in the span range of the composite coupling beam and in the anchorage area, and a certain number of open-hole double steel plates with quadrilateral stirrups, longitudinal reinforcement and waist reinforcement were arranged in the span range of the coupling beam- Concrete composite coupling beams have shown good seismic performance.

The construction technology of the perforated double steel plate-concrete composite connecting beam of the present invention:

The skeleton of the perforated double-steel plate-concrete composite connecting beam connects two steel plates of corresponding specifications into a whole through threaded restraint rods or patch plates as required, and processes the steel plates according to the perforation ratio and perforation form required by the design, among which The shear studs are welded to the surface of the double steel plates, which can be manufactured by a professional steel structure company, and then transported to the construction site, and then tied with the longitudinal reinforcement, waist reinforcement and stirrup, so as to further formwork and pour concrete.

When using open-hole double-steel plate-concrete composite coupling beams to connect with concrete shear walls to form a combined limb shear wall structure, the composite coupling beams must be anchored into the concrete shear walls with sufficient design length or other anchoring measures shall be taken to ensure that the wall For the effective connection of beam joints, the double steel plate-concrete composite coupling beam with openings is connected with the concrete shear wall according to the design, and finally the overall pouring is carried out. The double steel plate-concrete composite connecting beam with openings designed by the invention improves the energy dissipation capacity of the connecting beam, improves the seismic performance of the connecting beam, and is convenient and fast in construction, creating certain social and economic benefits.

Claims (5)

1. A kind of perforated double steel plate-concrete composite connecting beam, comprises concrete beam, and is arranged in the concrete beam by longitudinal steel bar (4), waist bar (6), along longitudinal steel bar (4) and waist bar (6) level The steel bar frame formed by the surrounding stirrups (5) is composed of a concrete beam and a steel bar frame to form a reinforced concrete connecting beam. The beam and the shaped steel frame constitute a combined connecting beam; the shaped steel frame consists of a pair of perforated steel plates (1) symmetrically distributed, a restraint tie rod (2) connecting the pair of perforated steel plates (1) and a pair of perforated steel plates ( 1) It consists of shear studs (3) arranged vertically and uniformly on the surface, and the pair of perforated steel plates (1) are respectively provided with perforated openings (7); The restraining rod (2) is a threaded structure or a plate-plate structure, and the plate-plate structure is composed of several stiffeners welded symmetrically on both sides of the steel plate, and the stiffeners are welded by a small rectangular thin steel plate; The distance between the centers of the pair of perforated steel plates (1) is 1/3 of the section width of the combined connecting beam; The height of the perforated steel plate (1) is not less than 70% of the section height of the combined connecting beam, and the height-thickness ratio of the perforated steel plate (1) is not greater than 100; The section steel ratio of the combined connecting beam is 7.0%; The perforation ratio of the perforated hole (7) on the perforated steel plate (1) is 12%; The span-to-height ratio of the composite connecting beam is 2.5; The energy consumption ratio β of the combined connecting beam is 22.13, and the ductility coefficient μ is 6.4. 2. The perforated double steel plate-concrete composite connecting beam according to claim 1, characterized in that: the perforated opening (7) of the perforated steel plate (1) placed in the reinforced concrete connecting beam is along the perforated steel plate (1) It is distributed symmetrically up and down, and the openings (7) are double-row circular or double-row rectangular. 3. The perforated double-steel plate-concrete composite connecting beam according to claim 2, characterized in that: the stirrups (5) horizontally surrounded by the longitudinal reinforcement (4) and the double-row symmetrically distributed perforated openings (7 ) corresponds to the connection. 4. The perforated double steel plate-concrete composite connecting beam according to claim 1, characterized in that: the shear studs (3) arranged vertically and evenly on the surface of the perforated steel plate (1) are along the perforated steel plate (1) surface distribution. 5. The perforated double-steel plate-concrete composite connecting beam according to claim 1, characterized in that: the restraining rods (2) connecting the perforated steel plates (1) are distributed along the perforated steel plates (1) Hole (7) periphery is evenly distributed.