FRP strip-shaped spiral reinforcement cage, large-diameter secant pile and foundation pit support system

Abstract

The utility model provides an FRP strip-shaped spiral reinforcement cage, a large-diameter secant pile and a foundation pit support system. The FRP strip-shaped spiral reinforcement cage, the large-diameter secant pile and the foundation pit support system are used for solving the problem that in the prior art, stirrups and reinforcements of secant piles are inconvenient to construct the large-diameter secant pile. Comprising a plurality of FRP longitudinal bars, a plurality of first FRP stirrups and a plurality of second FRP stirrups. The first FRP stirrups and the second FRP stirrups are spirally wound, so that stress can be better dispersed and resisted when the reinforcement cage is subjected to external force, and the bearing capacity of the reinforcement cage is improved; in addition, the included angle formed between the first FRP stirrup and the second FRP stirrup is a non-right angle, so that the complexity and the flexibility of the reinforcement cage are improved, and the torsion resistance of the reinforcement cage can be improved; in addition, due to the fact that the FRP material is adopted, the dead weight of the whole reinforcement cage is reduced, the reinforcement cage manufactured for the large-diameter secant pile can be conveniently transported, the reinforcement cage can be conveniently placed into a pouring hole, and the construction difficulty of the secant pile is reduced.

Description

Technical Field

[0001] The utility model belongs to the field of construction, and particularly relates to an FRP strip spiral reinforcement cage, a large-diameter secant pile and a foundation pit retaining system. Background Art

[0002] A secant pile is a foundation pit retaining structure formed by arranging piles in an interlocking manner. It is usually composed of two different types of piles, namely pile A and pile B, which are interlocked with each other to form a vertical continuum with the functions of soil retaining and water cutoff. The secant pile can not only be used as a soil retaining member but also play a role in water cutoff, thus eliminating the need for an additional water cutoff curtain. In addition, compared with traditional pile types, the secant pile has a lower reinforcement ratio, reducing the material cost. Moreover, due to the tight interlocking between piles, a good overall continuous structure is formed, improving the mechanical properties. In addition, the construction method of the secant pile is flexible and can be adjusted according to the specific engineering requirements.

[0003] However, the reinforcement cage of the traditional secant pile is made of steel bars. Due to the characteristics of steel bars, it is easily affected by corrosion, and its load-bearing capacity will decrease with the increase of service life. In addition, for large buildings, large-diameter secant piles are usually required. The larger the diameter of the secant pile, the greater the load it needs to bear. In the prior art, in order to enhance the strength of the reinforcement cage of the large-diameter secant pile, the method of increasing the number of steel bars or increasing the diameter of the steel bars is usually adopted. However, this method increases the weight of the reinforcement cage, making it inconvenient for transportation and placement into the pouring hole, and increasing the construction difficulty of the large-diameter secant pile. Summary of the Utility Model

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present utility model is to provide an FRP strip spiral reinforcement cage, a large-diameter secant pile and a foundation pit retaining system, which are used to solve the problem that the reinforcement cage of the secant pile in the prior art is not convenient for the construction of large-diameter secant piles.

[0005] To achieve the above purpose and other related purposes, the present utility model provides an FRP strip spiral reinforcement cage, comprising: a plurality of FRP longitudinal bars, a plurality of first FRP stirrups and a plurality of second FRP stirrups; the plurality of FRP longitudinal bars are arranged at intervals in the vertical direction and enclose a cylindrical structure; the plurality of first FRP stirrups and the plurality of second FRP stirrups are spirally wound around the outside of the cylindrical structure enclosed by the plurality of FRP longitudinal bars; the plurality of first FRP stirrups and the plurality of second FRP stirrups are arranged in parallel; the included angle formed between the first FRP stirrup and the second FRP stirrup is non-right angle.

[0006] Optionally, the plurality of first FRP stirrups and the plurality of second FRP stirrups are intertwined to form a woven mesh structure.

[0007] Optionally, the number of multiple first FRP stirrups is the same as that of the second FRP stirrup.

[0008] Optionally, the material of the first FRP stirrup is carbon fiber reinforced composite material or glass fiber reinforced composite material; and / or, the material of the second FRP stirrup is carbon fiber reinforced composite material or glass fiber reinforced composite material.

[0009] Optionally, the material of the FRP longitudinal bars is carbon fiber reinforced composite material or glass fiber reinforced composite material.

[0010] Optionally, the diameter of the FRP longitudinal bars is greater than the diameters of the first FRP stirrup and the second FRP stirrup.

[0011] Optionally, the ratio of the diameter of the FRP longitudinal bars to the diameter of the first FRP stirrup is 2:1; and / or, the ratio of the diameter of the FRP longitudinal bars to the diameter of the second FRP stirrup is 2:1.

[0012] On the other hand, a large-diameter secant pile is also provided, including concrete and an FRP strip spiral reinforcement cage as described above.

[0013] Optionally, the concrete is high-strength concrete or polymer concrete.

[0014] On yet another aspect, a foundation pit retaining system includes a plurality of large-diameter secant piles as described above, and the large-diameter secant piles are bored cast-in-place piles or spiral bored cast-in-place piles.

[0015] As described above, an FRP strip spiral reinforcement cage, a large-diameter secant pile and a foundation pit retaining system of the present utility model have at least the following beneficial effects: By adopting a spiral winding method for both the first FRP stirrup and the second FRP stirrup, when the reinforcement cage is subjected to external forces, it can better disperse and resist stress, thereby improving the bearing capacity of the reinforcement cage. In addition, the included angle formed between the first FRP stirrup and the second FRP stirrup is non-right angle, which increases the complexity and flexibility of the reinforcement cage and can also improve the torsional resistance of the reinforcement cage; at the same time, the design of the non-right angle also enables the reinforcement cage to better adapt to and resist deformations in various directions when subjected to external forces. Furthermore, due to the use of FRP materials, the reinforcement cage has the characteristics of high strength and light weight, enabling the reinforcement cage to maintain good stability and durability when bearing large loads, while reducing the self-weight of the entire reinforcement cage, facilitating the transportation of the reinforcement cage made for large-diameter secant piles and the placement of the reinforcement cage into the casting hole, and reducing the construction difficulty of the secant pile; and the reinforcement cage has good corrosion resistance and fatigue resistance, which enables the reinforcement cage to be used in harsh environments for a long time without damage. Description of the Drawings

[0016] Figure 1Shown is a schematic structural view of an FRP strip spiral reinforcement cage of the present utility model.

[0017] Figure 2 Shown is a schematic view of the first FRP stirrup and the second FRP stirrup of the present utility model intertwined into a woven mesh structure.

[0018] Element number description:

[0019] 1. FRP longitudinal reinforcement, 2. First FRP stirrup, 3. Second FRP stirrup Detailed implementation manners

[0020] The following specific embodiments illustrate the implementation manners of the present utility model. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification.

[0021] Please refer to all the following drawings. It should be noted that the structures, proportions, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in the art to understand and read, and are not used to limit the limited conditions under which the present utility model can be implemented. Therefore, they do not have a substantial technical meaning. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear description and are not used to limit the scope under which the present utility model can be implemented. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope within which the present utility model can be implemented.

[0022] The following various embodiments are only for illustration purposes. Combinations can be made between the various embodiments, and it is not limited to the content shown in the following single embodiments.

[0023] Please refer to Figure 1-2, the present utility model provides an FRP strip spiral reinforcement cage, comprising: a plurality of FRP longitudinal bars 1, a plurality of first FRP stirrups 2 and a plurality of second FRP stirrups 3; the plurality of FRP longitudinal bars are arranged at intervals in the vertical direction and enclose a cylindrical structure; the plurality of first FRP stirrups 2 and the plurality of second FRP stirrups 3 are spirally wound around the outside of the cylindrical structure enclosed by the plurality of FRP longitudinal bars; the first FRP stirrups 2 and the second FRP stirrups 3 are arranged in parallel; the angle formed between the first FRP stirrup 2 and the second FRP stirrup 3 is non-right angle. Specifically, the first FRP stirrup 2 and the second FRP stirrup 3 spirally surround the plurality of FRP longitudinal bars from the bottom of the FRP longitudinal bar 1 and are arranged at intervals in the vertical direction and enclose the outside of the cylindrical structure until spirally extending to the top of the FRP longitudinal bar 1. The angle formed between the first FRP stirrup 2 and the second FRP stirrup 3 is non-right angle. As Figure 2 shown, the smaller angle β formed between the first FRP stirrup 2 and the second FRP stirrup 3 is an acute angle.

[0024] In this embodiment, by adopting the spiral winding method for both the first FRP stirrup 2 and the second FRP stirrup 3, when the reinforcement cage is subjected to external forces, it can better disperse and resist stress, thereby improving the bearing capacity of the reinforcement cage. In addition, the angle formed between the first FRP stirrup 2 and the second FRP stirrup 3 is non-right angle, which increases the complexity and flexibility of the reinforcement cage and can also improve the torsional resistance of the reinforcement cage; at the same time, the design of the non-right angle also enables the reinforcement cage to better adapt to and resist deformations in various directions when subjected to external forces. In addition, due to the use of FRP material, the reinforcement cage has the characteristics of high strength and light weight, so that when the reinforcement cage bears a large load, it can maintain good stability and durability, while reducing the self-weight of the reinforcement cage, facilitating the transportation of the reinforcement cage made for large-diameter secant piles and putting the reinforcement cage into the perfusion hole, reducing the construction difficulty of the secant pile; and the reinforcement cage has good corrosion resistance and fatigue resistance, which enables the reinforcement cage to be used for a long time in a harsh environment without damage.

[0025] The plurality of first FRP stirrups 2 and the plurality of second FRP stirrups 3 are intertwined to form a woven mesh structure. The first FRP stirrups 2 and the second FRP stirrups 3 intertwined into a woven mesh can support and restrain each other to form an overall stable structure. On the one hand, when subjected to external forces, it can better disperse and resist stress, improving the overall stability of the reinforcement cage; on the other hand, it can also improve the shear and torsional resistance of the reinforcement cage, and can effectively resist various complex external forces, improving the bearing capacity and safety of the reinforcement cage.

[0026] In one embodiment, the number of the first FRP stirrups 2 and the second FRP stirrups 3 is the same. For example, the number of the first FRP stirrups 2 is 10, and the corresponding number of the second FRP stirrups 3 is also 10. Of course, in other embodiments, the number of the first FRP stirrups 2 and the second FRP stirrups 3 can be set to be different. In this regard, the present application does not make any restrictions.

[0027] The materials for making the first FRP stirrups 2, the second FRP stirrups 3 and the FRP longitudinal bars 1 can be carbon fiber reinforced composite materials, or can also be glass fiber reinforced composite materials.

[0028] The diameter of the FRP longitudinal bars 1 is greater than the diameters of the first FRP stirrups 2 and the second FRP stirrups 3. Specifically, the FRP longitudinal bars 1 mainly bear tensile forces in the reinforcement cage, and the stirrups mainly play a role in restraint and support. In the embodiment, the diameter of the FRP longitudinal bars 1 is set to be greater than the diameters of the first FRP stirrups 2 and the second FRP stirrups 3. In an alternative embodiment, the ratio of the diameter of the FRP longitudinal bars 1 to the diameter of the first FRP stirrups 2 can be 2:1, and the ratio of the diameter of the FRP longitudinal bars 1 to the diameter of the second FRP stirrups 3 can be 2:1. In this embodiment, the diameters of the first FRP stirrups 2 and the second FRP stirrups 3 are set to be the same, that is, the ratio of the diameter of the FRP longitudinal bars 1 to the first FRP stirrups 2 and the ratio of the diameter of the FRP longitudinal bars 1 to the second FRP stirrups 3 are both 2:1, so as to ensure the matching and coordination of the mechanical properties of the longitudinal bars and the stirrups.

[0029] On the other hand, the present utility model also provides a large-diameter secant pile, which includes concrete and the above-mentioned FRP strip spiral reinforcement cage. During use, after the FRP strip spiral reinforcement cage is placed into the perfusion hole, by filling the perfusion hole with concrete, concrete is provided between adjacent two first FRP stirrups 2, between adjacent two second FRP stirrups 3, between adjacent first FRP stirrups 2 and second FRP stirrups 3, and between the first FRP stirrups 2 and the second FRP stirrups 3 and the surface of the perfusion hole, so as to enhance the bonding performance between the first FRP stirrups 2 and the second FRP stirrups 3 and the pile body. In an alternative embodiment, the concrete is high-strength concrete or polymer concrete.

[0030] On the one hand, the present utility model also provides a foundation pit retaining system, which includes a plurality of the above-mentioned large-diameter secant piles, and the large-diameter secant piles are bored cast-in-place piles or spiral bored cast-in-place piles. A foundation pit retaining system also includes a plurality of plain concrete piles, and the large-diameter secant piles are used between two adjacent plain concrete piles.

[0031] In summary, in the present utility model, both the first FRP stirrup 2 and the second FRP stirrup 3 are helically wound, enabling the reinforcement cage to better disperse and resist stress when subjected to external forces, thereby improving the load-bearing capacity of the reinforcement cage. Additionally, the angle formed between the first FRP stirrup 2 and the second FRP stirrup 3 is non-right-angled, increasing the complexity and flexibility of the reinforcement cage and also enhancing its torsional resistance; at the same time, the non-right-angled angle design also enables the reinforcement cage to better adapt to and resist deformations in various directions when subjected to external forces. Furthermore, due to the use of FRP material, the reinforcement cage has the characteristics of high strength and light weight, enabling the reinforcement cage to maintain good stability and durability when bearing large loads, while reducing the self-weight of the reinforcement cage, facilitating the transportation of the reinforcement cage made for large-diameter secant piles and placing the reinforcement cage into the perfusion hole, reducing the construction difficulty of the secant piles; and the reinforcement cage has good corrosion resistance and fatigue resistance, enabling the reinforcement cage to be used for a long time in a harsh environment without damage. Therefore, the present utility model effectively overcomes various drawbacks in the prior art and has high industrial utilization value.

[0032] The above embodiments merely illustrate the principles and effects of the present utility model and are not intended to limit the present utility model. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present utility model. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present utility model should still be covered by the claims of the present utility model.

Claims

1. A FRP strip spiral reinforcement cage, characterized in that, Comprising: a plurality of FRP longitudinal bars, a plurality of first FRP stirrups and a plurality of second FRP stirrups; the plurality of FRP longitudinal bars are arranged at intervals in the vertical direction and enclose a cylindrical structure; the plurality of first FRP stirrups and the plurality of second FRP stirrups are spirally wound around the outside of the cylindrical structure enclosed by the plurality of FRP longitudinal bars; the plurality of first FRP stirrups and the plurality of second FRP stirrups are arranged in parallel; the included angle formed between the first FRP stirrup and the second FRP stirrup is non-right angle.

2. The FRP strip-shaped spiral steel reinforcement cage according to claim 1, wherein: the plurality of first FRP stirrups and the plurality of second FRP stirrups are intertwined to form a woven mesh structure.

3. A FRP strip spiral reinforcement cage according to claim 1, characterized in that: the number of the plurality of first FRP stirrups is the same as the number of the second FRP stirrups; 4. A FRP strip-shaped spiral reinforcement cage according to claim 1, characterized in that: the material of the first FRP stirrup is carbon fiber reinforced composite material or glass fiber reinforced composite material; and / or, the material of the second FRP stirrup is carbon fiber reinforced composite material or glass fiber reinforced composite material.

5. The FRP strip spiral reinforcement cage according to claim 4, wherein: the material of the FRP longitudinal bar is carbon fiber reinforced composite material or glass fiber reinforced composite material.

6. A FRP strip spiral reinforcement cage according to claim 1, characterized in that: the diameter of the FRP longitudinal bar is greater than the diameters of the first FRP stirrup and the second FRP stirrup.

7. A FRP strip-shaped spiral steel bar cage according to claim 1, characterized in that: the diameter ratio of the FRP longitudinal bar to the first FRP stirrup is 2:1; and / or, the diameter ratio of the FRP longitudinal bar to the second FRP stirrup is 2:

1.

8. A large-diameter secant pile, characterized in that: Comprising concrete and an FRP strip spiral cage as described in any one of claims 1-7.

9. The large-diameter secant pile according to claim 8, characterized in that: The concrete is high-strength concrete or polymer concrete.

10. A foundation pit retaining system, characterized in that: Comprising a plurality of large-diameter secant piles as described in any one of claims 8-9, and the large-diameter secant pile is a bored cast-in-place pile or a spiral bored cast-in-place pile.

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