Anti-crack prestressed concrete pipe pile

Abstract

This invention provides a crack-resistant prestressed concrete pipe pile, comprising a concrete pile body, a main reinforcing cage and an auxiliary reinforcing cage coaxially arranged within the concrete pile body, and a fiber-reinforced concrete protective layer disposed on the outer wall of the concrete pile body. The main reinforcing cage includes multiple prestressed main bars distributed at equal intervals along the circumference and spiral stirrups wound around the prestressed main bars. The auxiliary reinforcing cage includes multiple non-prestressed reinforcing bars distributed at equal intervals along the circumference outside the main reinforcing cage and multiple annular stirrups fixed at equal intervals along the axial direction to the non-prestressed reinforcing bars. Short steel anchors embedded in the fiber-reinforced concrete protective layer are fixed to the outside of the annular stirrups. The crack-resistant prestressed concrete pipe pile of this invention significantly improves the crack resistance, ductility, and durability of the pipe pile through double reinforcement constraint and mechanical interlocking structure, combined with the fiber-reinforced concrete protective layer.

Description

Technical Field

[0001] This utility model belongs to the field of foundation pile technology in civil engineering, and in particular relates to a crack-resistant prestressed concrete pipe pile. Background Technology

[0002] Prestressed concrete pipe piles have advantages such as uniform stress distribution, good pile quality, easy pile placement, and low overall cost, and are widely used in industrial and civil buildings, bridges, highways, railways, ports, water conservancy projects, etc. However, existing technologies have the following problems: traditional pipe piles are prone to tensile fracture of the main reinforcement when subjected to bending, cracks propagate rapidly, have poor ductility, and pose a risk of brittle failure; under corrosive environments or repeated loading, transverse cracks are prone to appear in the pile body, leading to steel corrosion, reduced bearing capacity, and insufficient crack resistance; ordinary spiral stirrups provide insufficient restraint to the core concrete, and have limited crack control capabilities. Utility Model Content

[0003] In view of this, in order to solve the above-mentioned technical problems, this utility model proposes a crack-resistant prestressed concrete pipe pile that improves crack resistance, ductility and durability through double reinforcement constraint and mechanical interlocking structure.

[0004] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0005] A crack-resistant prestressed concrete pipe pile includes a concrete pile body, a main reinforcing cage and an auxiliary reinforcing cage coaxially arranged within the concrete pile body, and a fiber-reinforced concrete protective layer disposed on the outer wall of the concrete pile body; the main reinforcing cage includes a plurality of prestressed main bars distributed at equal intervals along the circumference and spiral stirrups wound around the prestressed main bars; the auxiliary reinforcing cage includes a plurality of non-prestressed reinforcing bars distributed at equal intervals along the circumference outside the main reinforcing cage and a plurality of annular stirrups fixed at equal intervals along the axial direction to the non-prestressed reinforcing bars; short steel anchors embedded in the fiber-reinforced concrete protective layer are fixed to the outside of the annular stirrups.

[0006] Non-prestressed steel bars disperse crack stress, suppress crack width, provide redundant bearing capacity, and avoid instantaneous failure after the main reinforcement breaks; the double-layer stirrup pattern of spiral stirrups and ring stirrups strongly confines the concrete and delays crack propagation; the fiber-reinforced concrete protective layer incorporates polypropylene fibers to isolate corrosive media and extend the service life of the concrete pile.

[0007] Short steel bar anchors are embedded in the fiber-reinforced concrete cover to form a "stud-type" anchoring structure. When the concrete pile is bent, the fiber-reinforced concrete cover and the concrete pile may generate interfacial shear stress. The short steel bar anchors embedded in the fiber-reinforced concrete cover and the concrete form a local "mortise and tenon structure" to achieve mechanical interlocking. At the same time, the interfacial shear force is converted into tensile stress in the short steel bar anchors, which is transferred to the auxiliary steel cage through the welding point to achieve stress dispersion.

[0008] Furthermore, the number of prestressed main reinforcement bars is 6-20, located at one-third to two-thirds of the radius of the concrete pile; the main pitch of the spiral stirrups is 80-100mm, and the pitch is increased within 1 meter of the pile head and pile tail, with a pitch of 50-80mm in the increased pitch zone.

[0009] Furthermore, the number of non-prestressed steel bars is 8-25, located at two-thirds to four-fifths of the radius of the concrete pile and at a distance of more than 30mm from the prestressed main reinforcement; the spacing between adjacent annular stirrups is 200-300mm.

[0010] Furthermore, the short steel bar anchor is vertically fixed to the outer surface of the annular stirrup, and its axial direction is consistent with the radial direction of the concrete pile; there are multiple short steel bar anchors, which are evenly distributed along the circumference of the annular stirrup.

[0011] Furthermore, the short steel bar anchor is embedded in the fiber-reinforced concrete protective layer to a depth of 15-30 mm.

[0012] Furthermore, the prestressed main reinforcement is fixed to the spiral stirrup by binding, the non-prestressed steel bar is fixed to the annular stirrup by welding, and the short steel bar anchor is fixed to the annular stirrup by welding.

[0013] Each ring stirrup is fully welded to all non-prestressed steel bars at its intersection to form a rigid grid; the spiral stirrups are fixed to the prestressed main bars by binding to avoid the high temperature of welding affecting the performance of the prestressed main bars.

[0014] Furthermore, the thickness of the fiber-reinforced concrete protective layer is 50-80 mm.

[0015] Compared with existing technologies, the crack-resistant prestressed concrete pipe pile of this utility model has the following advantages:

[0016] (1) The crack-resistant prestressed concrete pipe pile of this utility model adopts a double-layer composite steel cage system and a short steel anchor structure, and at the same time, it is combined with a fiber-reinforced concrete protective layer to improve the crack resistance, ductility and durability of the pipe pile.

[0017] (2) The crack-resistant prestressed concrete pipe pile of this utility model adopts non-prestressed steel bars to form a "stress diffusion network" on the outside of the prestressed main reinforcement, which disperses the concentrated cracks into micro cracks and realizes the synergistic crack resistance of the double reinforcement; the inner layer of spiral stirrups is wound with high density to suppress the lateral expansion of the core concrete, and the outer layer of annular stirrups with rigid mesh restricts the displacement of non-prestressed steel bars, reduces the crack propagation speed, and realizes the double constraint of stirrups; effectively improving the crack resistance performance of the pipe pile;

[0018] (3) In the crack-resistant prestressed concrete pipe pile of the present invention, when the main reinforcement is fractured by tension, the non-prestressed steel reinforcement immediately bears the load to avoid instantaneous collapse. The double-layer stirrups provide a strong confinement concrete effect, and the ductility and redundant bearing capacity are significantly enhanced to avoid brittle failure.

[0019] (4) In the crack-resistant prestressed concrete pipe pile described in this utility model, short steel bar anchors are used to form a "stud-like" interlock with the fiber-reinforced concrete protective layer, which improves the interface shear strength, eliminates the risk of fiber-reinforced concrete protective layer detachment, and extends the durability of the pipe pile. Attached Figure Description

[0020] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0021] Figure 1 This is a schematic diagram of the internal cross-sectional structure of the crack-resistant prestressed concrete pipe pile described in this embodiment of the utility model;

[0022] Figure 2 This is a side view of the main steel cage as described in an embodiment of the present utility model;

[0023] Figure 3 This is a side view of the auxiliary steel cage described in an embodiment of the present invention.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1-Concrete pile, 2-Main reinforcement cage, 3-Auxiliary reinforcement cage, 4-Fiber reinforced concrete protective layer, 5-Prestressed main reinforcement, 6-Helical stirrup, 7-Non-prestressed reinforcement, 8-Ring stirrup, 9-Short reinforcement anchor. Detailed Implementation

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0027] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0028] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0029] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0030] like Figures 1 to 3 As shown, a crack-resistant prestressed concrete pipe pile includes a concrete pile body 1, a main steel cage 2 and an auxiliary steel cage 3 embedded in the concrete pile body 1 and arranged coaxially, and a fiber-reinforced concrete protective layer 4 provided on the outer wall of the concrete pile body 1.

[0031] The main reinforcement cage 2 includes multiple prestressed main bars 5 evenly distributed along the circumference and spiral stirrups 6 wound around the prestressed main bars 5; the prestressed main bars 5 and the spiral stirrups 6 are fixed by binding; there are 12 prestressed main bars 5, located at half the radius of the concrete pile body 1; the main pitch of the spiral stirrups 6 is 100mm, and the pitch is 50mm within 1 meter of the pile head and pile tail.

[0032] The auxiliary steel cage 3 includes multiple non-prestressed steel bars 7 distributed at equal intervals along the circumference outside the main steel cage 2 and multiple annular stirrups 8 fixed at equal intervals along the axial direction on the non-prestressed steel bars 7; the non-prestressed steel bars 7 and the annular stirrups 8 are fixed by welding; there are 16 non-prestressed steel bars 7, located at three-quarters of the radius of the concrete pile body 1; the spacing between adjacent annular stirrups 8 is 200mm.

[0033] Short steel bar anchors 9 are fixed to the outside of the annular stirrup 8 and embedded in the fiber-reinforced concrete protective layer 4. The short steel bar anchors 9 are welded vertically to the outer surface of the annular stirrup 8 and their axial direction is consistent with the radial direction of the concrete pile 1. There are multiple short steel bar anchors 9, which are evenly distributed along the circumference of the annular stirrup 8. The depth of the short steel bar anchors 9 embedded in the fiber-reinforced concrete protective layer 4 is 15-30mm.

[0034] The thickness of the fiber-reinforced concrete protective layer 4 is 60mm.

[0035] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A crack-resistant prestressed concrete pipe pile, characterized in that: The structure includes a concrete pile, a main reinforcing cage and an auxiliary reinforcing cage embedded in the concrete pile, and a fiber-reinforced concrete protective layer on the outer wall of the concrete pile. The main reinforcing cage includes multiple prestressed main bars distributed at equal intervals along the circumference and spiral stirrups wrapped around the prestressed main bars. The auxiliary reinforcing cage includes multiple non-prestressed reinforcing bars distributed at equal intervals along the circumference outside the main reinforcing cage and multiple annular stirrups fixed at equal intervals along the axial direction to the non-prestressed reinforcing bars. Short steel anchors embedded in the fiber-reinforced concrete protective layer are fixed to the outside of the annular stirrups.

2. The crack-resistant prestressed concrete pipe pile according to claim 1, characterized in that: The number of prestressed main reinforcement bars is 6-20, located at one-third to two-thirds of the radius of the concrete pile; the main pitch of the spiral stirrups is 80-100mm, and the pitch is increased within 1 meter of the pile head and pile tail, with a pitch of 50-80mm in the increased pitch zone.

3. The crack-resistant prestressed concrete pipe pile according to claim 1, characterized in that: The number of non-prestressed steel bars is 8-25, located at two-thirds to four-fifths of the radius of the concrete pile and at a distance of more than 30mm from the prestressed main reinforcement; the spacing between adjacent annular stirrups is 200-300mm.

4. The crack-resistant prestressed concrete pipe pile according to claim 1, characterized in that: The short steel bar anchor is vertically fixed to the outer surface of the annular stirrup, and its axial direction is consistent with the radial direction of the concrete pile; there are multiple short steel bar anchors, which are evenly distributed along the circumference of the annular stirrup.

5. The crack-resistant prestressed concrete pipe pile according to claim 1, characterized in that: The short steel bar anchor is embedded in the fiber-reinforced concrete protective layer to a depth of 15-30 mm.

6. The crack-resistant prestressed concrete pipe pile according to claim 1, characterized in that: The prestressed main reinforcement is fixed to the spiral stirrup by binding, the non-prestressed steel bar is fixed to the annular stirrup by welding, and the short steel bar anchor is fixed to the annular stirrup by welding.

7. The crack-resistant prestressed concrete pipe pile according to claim 1, characterized in that: The thickness of the fiber-reinforced concrete protective layer is 50-80 mm.

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