Reinforcing cages and reinforced concrete piles with bidirectional spiral winding stirrups
By employing a bidirectional spiral-wound stirrup structure in reinforced concrete piles, the problems of loose stirrups and insufficient shear bearing capacity were solved, thereby improving structural strength and seismic performance. The structure also forms a three-dimensional spatial grid constraint, enhancing overall quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGXI THE FIRST CONSTR ENG CORP
- Filing Date
- 2025-07-08
- Publication Date
- 2026-06-09
AI Technical Summary
In existing reinforced concrete piles, the stirrups are prone to loosening and displacement, resulting in insufficient seismic performance and uneven shear bearing capacity, which leads to potential quality problems.
The structure employs a bidirectional spiral winding stirrup, with the first and second stirrups alternating on the inner and outer sides of the main reinforcement, and the spiral directions being opposite, forming a three-dimensional spatial grid constraint. The main reinforcement and stirrups are fixedly connected, forming a spatial truss effect.
It improves the structural strength and shear bearing capacity of reinforced concrete piles, enhances the confinement effect of concrete, delays crack propagation, improves seismic performance and deformation capacity, and reduces the risk of steel cage torsion.
Smart Images
Figure CN224338220U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of construction, and in particular to a steel cage and reinforced concrete pile with a bidirectional spiral winding stirrup structure. Background Technology
[0002] In reinforced concrete piles, stirrups are placed outside the main reinforcement bars. After the stirrups are tied to the main reinforcement bars, they are prone to loosening and displacement, and their restraining effect on the core concrete is uneven. This results in poor seismic performance, insufficient shear bearing capacity, and potential quality problems. Utility Model Content
[0003] This utility model provides a steel cage and reinforced concrete pile with a bidirectional spiral winding stirrup structure, which can effectively improve structural strength and overall quality.
[0004] On the one hand, this utility model provides a steel cage with a bidirectional spiral winding stirrup structure, including main bars and stirrups. The main bars are multiple and arranged in a circular ring at equal intervals. The main bars are cylindrical and the multiple main bars are divided into multiple groups, with each group containing 2-3 adjacent main bars.
[0005] The stirrups include a first stirrup and a second stirrup, which are spirally wound around multiple main reinforcing bars, with opposite spiral directions. The first stirrup and the second stirrup are alternately located on the inner and outer sides of multiple sets of main reinforcing bars. On a plane perpendicular to the main reinforcing bars, the projections of the first stirrup and the second stirrup between two adjacent sets of main reinforcing bars are intersecting. The main reinforcing bars are located between the first stirrup and the second stirrup, and each main reinforcing bar is fixedly connected to the first stirrup and the second stirrup.
[0006] The first and second stirrups located inside the main reinforcement are in a straight line, while the first and second stirrups located outside the main reinforcement are in an arc shape.
[0007] In the plane perpendicular to the main reinforcement bar, the projection of the first stirrup is a rounded rectangle, and the projection of the second stirrup is a rounded rectangle.
[0008] There are 16 main reinforcing bars, and each pair of main reinforcing bars forms a group.
[0009] The first stirrup and the second stirrup have a mirror-symmetrical structure.
[0010] Wherein, the bottom end of the first stirrup intersects and is fixedly connected to the bottom end of the second stirrup, and the top end of the first stirrup intersects and is fixedly connected to the top end of the second stirrup.
[0011] The first stirrup and the second stirrup form multiple side intersections on the side of the steel cage, and the first stirrup and the second stirrup are fixedly connected at all side intersections.
[0012] The helix angle of the first stirrup and the second stirrup is 15°-25°.
[0013] The diameter of the stirrup is 1 / 4 to 1 / 3 of the diameter of the main reinforcement.
[0014] On the other hand, the present invention provides a reinforced concrete pile, characterized in that it includes concrete and the aforementioned reinforcing cage having a bidirectional spiral winding stirrup structure, wherein the concrete is poured into the reinforcing cage.
[0015] The present invention provides a steel cage and reinforced concrete pile with a bidirectional spiral winding stirrup structure. The first stirrup and the second stirrup are alternately located on the inner and outer sides of multiple sets of main bars. Each main bar is clamped and fixed between the first stirrup and the second stirrup, which ensures that the main bars are reliably located between the first stirrup and the second stirrup, and the positions of the first stirrup and the second stirrup are not easily loosened. The first stirrup and the second stirrup are both spirally wound around multiple main bars, and the spiral directions of the two are opposite, providing the interaction of the bidirectional spiral structure, forming a three-dimensional spatial grid constraint, so that the concrete is in a multidirectional compressive state, delaying crack propagation, improving the concrete constraint efficiency, and improving the quality of the reinforced concrete pile. Attached Figure Description
[0016] Figure 1 A side view of a steel cage with a bidirectional spiral wound stirrup structure provided for a preferred embodiment of the present invention;
[0017] Figure 2 yes Figure 1 Orthographic projection of the steel reinforcement cage onto a plane perpendicular to the main reinforcement bars;
[0018] Figure 3 yes Figure 2 Orthographic projection of the first stirrup and multiple main bars of the steel reinforcement cage;
[0019] Figure 4 yes Figure 2 Orthographic projection of the second stirrup and multiple main bars in the steel reinforcement cage;
[0020] Figure 5 yes Figure 1 A three-dimensional structural diagram of the steel reinforcement cage. Detailed Implementation
[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.
[0022] In the diagram, units with similar structures are represented by the same labels.
[0023] This utility model provides a reinforced concrete pile, including a steel cage 200 with a bidirectional spiral winding stirrup structure and concrete, wherein the concrete is poured into the steel cage 200.
[0024] like Figures 1 to 5 As shown, in the preferred embodiment of this utility model, a steel cage 200 with a bidirectional spiral-wound stirrup structure is provided, which includes main bars 21 and stirrups 22. There are multiple main bars 21, which are arranged in a circular ring at equal intervals; each main bar 21 is cylindrical, and the stirrups 22 are arranged to wrap around the multiple main bars 21 to fix the multiple main bars 21 to form a solid steel cage 200.
[0025] like Figure 2 As shown, the main reinforcing bars 21 are divided into multiple groups, and each group contains 2-3 adjacent main reinforcing bars 21. The stirrups 22 include first stirrups 221 and second stirrups 222, which are spirally wound around the main reinforcing bars 21 in opposite directions. The first stirrups 221 and second stirrups 222 are alternately located on the inner and outer sides of the multiple groups of main reinforcing bars 21. On a plane perpendicular to the main reinforcing bars 21, the projections of the first stirrups 221 and second stirrups 222 between adjacent groups of main reinforcing bars 21 intersect. The main reinforcing bars 21 are located between the first stirrups 221 and second stirrups 222, and each main reinforcing bar 21 is fixedly connected to both the first stirrups 221 and second stirrups 222.
[0026] The first stirrup 221 and the second stirrup 222 are alternately located on the inner and outer sides of multiple sets of main reinforcement bars 21, and the projections of the alternating positions are intersecting. Each main reinforcement bar 21 is clamped and fixed between the first stirrup 221 and the second stirrup 222, which can reliably position the main reinforcement bar 21 between the first stirrup 221 and the second stirrup 222, and firmly fix the position of the main reinforcement bar 21. The positions of the first stirrup 221 and the second stirrup 222 are not easy to loosen, thereby enhancing the structural strength of the overall steel cage 200 and thus improving the structural strength of the overall reinforced concrete pile.
[0027] like Figure 1 , Figure 5As shown, both the first stirrup 221 and the second stirrup 222 are spirally wound around multiple main reinforcement bars 21, with opposite spiral directions. This provides a bidirectional spiral structure interaction, forming a three-dimensional spatial grid constraint. This keeps the concrete under multidirectional compression, delaying crack propagation and improving the concrete's confinement efficiency. The bidirectional spiral stirrup 22 provides continuous and uniform confinement force in the plastic hinge zone, improving the pile's deformation capacity and energy dissipation performance. The connection between the double-spiral stirrup 22 and the main reinforcement bars 21 creates a spatial truss effect, enhancing shear bearing capacity. The double-spiral structure forms a stable system during hoisting and pouring, reducing the risk of torsion of the reinforcement cage 200.
[0028] Combination Figure 2 , Figure 3 and Figure 4 As shown, multiple main reinforcing bars 21 are arranged in a circular pattern. The first and second stirrups located inside the main reinforcing bars 21 are straight, while the first and second stirrups located outside the main reinforcing bars 21 are arc-shaped. The curved structure of the first stirrup 221 and the second stirrup 222 is located outside the main reinforcing bars 21, which facilitates bending and construction.
[0029] Furthermore, on a plane perpendicular to the main reinforcement 21, as follows: Figure 3 As shown, the projection of the first stirrup 221 is a rounded rectangle, as... Figure 4 As shown, the projection of the second stirrup 222 is a rounded rectangle. The first stirrup 221 and the second stirrup 222 can be bent to form a simple rounded rectangle, which is beneficial for construction.
[0030] More specifically, there are 16 main reinforcement bars 21, arranged in a circular pattern with equal spacing, with each pair of main reinforcement bars 21 forming a group. The number and layout of these main reinforcement bars 21 allow the stirrups 22 to be bent into rounded rectangles.
[0031] The diameter of the stirrup 22 is smaller than that of the main reinforcement 21 to facilitate bending. The diameter of the stirrup 22 is preferably 1 / 4 to 1 / 3 of the diameter of the main reinforcement 21, which facilitates construction and allows the first stirrup 221 and the second stirrup 222 to be bent so that they are alternately located on the inside and outside of the main reinforcement 21.
[0032] The first stirrup 221 and the second stirrup 222 have a mirror-symmetrical structure, which further facilitates the improvement of the stress balance of the reinforcing cage 200. This symmetrical structure allows the bottom height and top height of the first stirrup 221 and the second stirrup 222 to be the same. Furthermore, as... Figure 5As shown, the bottom end of the first stirrup 221 intersects and is fixedly connected to the bottom end of the second stirrup 222, and the top end of the first stirrup 221 intersects and is fixedly connected to the top end of the second stirrup 222, so that the circumferential positions of the bottom and top ends of the first stirrup 221 and the second stirrup 222 are approximately the same. Fixing the two ends together further improves the structural strength. This can be achieved by welding or binding. Since the first stirrup 221 and the second stirrup 222 are symmetrical structures with opposite spiral directions, multiple side intersection points are formed on the side of the reinforcing cage 200 during their winding process. The first stirrup 221 and the second stirrup 222 are fixedly connected at all side intersection points to improve the structural strength of the reinforcing cage 200.
[0033] The helix angle of the first stirrup 221 and the second stirrup 222 is 15°-25° to increase the density of the first stirrup 221 and the second stirrup 222 in the axial direction of the main reinforcement, thereby further improving the overall structural strength.
[0034] The construction method of the reinforced concrete pile in this embodiment is as follows.
[0035] Step S210: Make a jig and use the jig to erect multiple main ribs 21 so that the multiple main ribs are arranged in a circular ring with equal spacing.
[0036] In this step, the main reinforcement 21 is fixed according to the construction drawings, based on the cross-sectional dimensions of the reinforced concrete pile and the number of main reinforcement 21.
[0037] Step S220: The main reinforcement bars are divided into groups of 2-3 adjacent main reinforcement bars 21; the stirrups 22 are wound around the main reinforcement bars 21, so that the first stirrup 221 and the second stirrup 222 are alternately located on the inside and outside of each group of main reinforcement bars 21, thereby forming a steel cage 200 with a bidirectional spiral wound stirrup structure.
[0038] This step specifically includes the following sub-steps.
[0039] Step S221: Wrap the first stirrup 221. The first stirrup 221 wraps around the outside of the first group of main reinforcement bars 21, then around the inside of the second group of main reinforcement bars 21, then around the outside of the third group of main reinforcement bars 21, and then around the inside of the fourth group of main reinforcement bars 21, and so on, until all the main reinforcement bars 21 have been wrapped. The number of times the first stirrup 221 wraps around the main reinforcement bars 21 can be determined according to the height of the reinforced concrete pile.
[0040] Step S222: Wrap the second stirrup 222. The second stirrup 222 wraps around the inside of the first group of main reinforcement bars 21, around the outside of the second group of main reinforcement bars 21, around the inside of the third group of main reinforcement bars 21, and around the outside of the fourth group of main reinforcement bars 21, repeating this operation until all main reinforcement bars 21 have been wrapped. The number of turns of the second stirrup 222 around the main reinforcement bars 21 is the same as the number of turns of the first stirrup 221 around the main reinforcement bars 21.
[0041] Both the first stirrup 221 and the second stirrup 222 are fixedly connected to the main reinforcement 21. Welding can be used; specifically, a resistance welding machine can be used to weld at each intersection of the first stirrup 221, the second stirrup 222, and the main reinforcement 21, with a welding time of 0.5~1.2 seconds. Alternatively, a binding method can be used, employing high-strength stainless steel binding wire in a cross-shaped binding, with a tensile strength ≥500MPa.
[0042] Step S230: Erect the cylindrical formwork.
[0043] In this step, a cylindrical formwork is erected on the outside of the steel cage 200.
[0044] Step S240: Pour concrete into the cylindrical formwork.
[0045] Based on the concrete grade of the piles in the construction drawings, select appropriate concrete mix proportions, pouring techniques, additives, and vibration measures to pour the concrete.
[0046] After pouring, cover with geotextile for moisture retention and curing, and conduct integrity and bearing capacity tests to complete the curing and testing.
[0047] The steel cage 200 provided in this embodiment adopts a two-way spiral collaborative constraint mechanism and spatial grid reinforcement. Through the orthogonality and internal and external winding of the outer spiral and inner spiral, a continuous rhomboid spatial grid structure is formed, which puts the concrete in a triaxial compression state and significantly improves the ultimate compressive strain of the core concrete. After the double spiral stirrups 22 are welded to the main reinforcement 21, they form a spatial truss system, and the load transfer path changes from unidirectional to multidirectional, reducing the risk of torsion of the steel cage 200.
[0048] The steel cage 200 provided in this embodiment has the following beneficial effects:
[0049] 1) Improves the confinement performance of concrete, placing the concrete in a multi-directional compressive state and delaying crack propagation;
[0050] 2) Improved structural performance of bidirectional spiral reinforced piles, including displacement ductility coefficient and shear bearing capacity;
[0051] 3) The bidirectional spiral stirrups provide continuous and uniform restraint force in the plastic hinge zone, improving the deformation capacity and energy dissipation performance of the pile body and enhancing its seismic performance;
[0052] 4) The double helix structure forms a stable system during hoisting and pouring, reducing the risk of steel cage twisting.
[0053] In summary, although the present invention has been disclosed above with reference to preferred embodiments, the above preferred embodiments are not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the claims.
Claims
1. A steel cage with a bidirectional helical winding stirrup structure, comprising main bars and stirrups, characterized in that, The main reinforcement bars are multiple and arranged in a circular ring with equal spacing; the main reinforcement bars are cylindrical, and the multiple main reinforcement bars are divided into multiple groups, with each group containing 2-3 adjacent main reinforcement bars; The stirrups include a first stirrup and a second stirrup, which are spirally wound around multiple main reinforcing bars, with opposite spiral directions. The first stirrup and the second stirrup are alternately located on the inner and outer sides of multiple sets of main reinforcing bars. On a plane perpendicular to the main reinforcing bars, the projections of the first stirrup and the second stirrup between two adjacent sets of main reinforcing bars are intersecting. The main reinforcing bars are located between the first stirrup and the second stirrup, and each main reinforcing bar is fixedly connected to the first stirrup and the second stirrup.
2. The steel cage with bidirectional helical winding stirrups according to claim 1, characterized in that, The first and second stirrups located inside the main reinforcement are in a straight line, while the first and second stirrups located outside the main reinforcement are in an arc shape.
3. The steel cage with bidirectional helical winding stirrups according to claim 2, characterized in that, On a plane perpendicular to the main reinforcement bar, the projection of the first stirrup is a rounded rectangle, and the projection of the second stirrup is a rounded rectangle.
4. The steel cage with bidirectional helical winding stirrups according to claim 3, characterized in that, There are 16 main reinforcing bars, and each pair of main reinforcing bars forms a group.
5. The steel cage with bidirectional helical winding stirrups according to claim 1, characterized in that, The first stirrup and the second stirrup have a mirror-symmetrical structure.
6. The steel cage with bidirectional helical winding stirrups according to claim 5, characterized in that, The bottom end of the first stirrup intersects and is fixedly connected to the bottom end of the second stirrup, and the top end of the first stirrup intersects and is fixedly connected to the top end of the second stirrup.
7. The steel cage with bidirectional helical winding stirrups according to any one of claims 1-6, characterized in that, The first stirrup and the second stirrup form multiple side intersections on the side of the steel cage, and the first stirrup and the second stirrup are fixedly connected at all side intersections.
8. The steel cage with bidirectional helical winding stirrups according to any one of claims 1-6, characterized in that, The helix angle of the first stirrup and the second stirrup is 15°-25°.
9. The steel cage with bidirectional helical winding stirrups according to any one of claims 1-6, characterized in that, The diameter of the stirrup is 1 / 4 to 1 / 3 of the diameter of the main reinforcement.
10. A reinforced concrete pile, characterized in that, The invention includes concrete and a steel cage with a bidirectional helical winding stirrup structure as described in any one of claims 1-9, wherein the concrete is poured into the steel cage.