Double-pile coupled beam foundation with anchor cables

Abstract

The utility model relates to the technical field of power transmission line tower foundation, and specifically provides a double-pile coupled beam foundation with anchor cable, which comprises a main pile, an auxiliary pile, a coupled beam and an anchor cable, the main pile and the auxiliary pile are connected by the coupled beam to form an integral stress structure, the anchor cable is connected with the main pile and anchored to the foundation stable layer, and the main pile and the auxiliary pile are horizontally arranged along the direction of the central pile of the power transmission line tower, the utility model can reduce the horizontal displacement of the foundation through the synergistic effect of the double pile and the coupled beam, the newly added anchor cable further improves the uplift bearing capacity and the overturning stability coefficient of the foundation, can effectively resist extreme loads such as strong wind and earthquake, and avoids the uplift of the pile body or the overall overturning.

Description

Technical Field

[0001] This utility model relates to the field of power transmission line tower foundation technology, specifically to a double-pile beam foundation with anchor cables. Background Technology

[0002] With the continuous expansion of power construction, transmission lines need to traverse various complex geological areas. In areas with soft soil foundations, collapsible loess, high groundwater levels, or large exposed tower foundations in mountainous regions, traditional monopile foundations often experience significant displacement due to insufficient bearing capacity or soil rheological properties, seriously affecting the safe operation of transmission lines.

[0003] Currently, the conventional method to address excessive pile top displacement is to increase the pile diameter to improve lateral stiffness. However, this method leads to an exponential increase in material costs, resulting in poor economic efficiency. Furthermore, existing twin-pile foundation structures often employ equal-diameter pile designs, failing to fully utilize the mechanical properties of the materials. The simple coupling beam structure is also ill-suited to the stress requirements of complex foundation conditions. Under extreme loads (such as strong winds and seismic loads), the foundation's uplift capacity and overturning stability still fall short of design requirements, increasing the risk of pile uplift and overall overturning.

[0004] Therefore, this utility model provides a double-pile beam foundation with anchor cables to solve the problems existing in the prior art. Utility Model Content

[0005] The purpose of this utility model is to provide a double-pile beam foundation with anchor cables to solve the technical problems existing in the prior art. The specific technical solution is as follows: A double-pile beam foundation with anchor cables includes main piles, auxiliary piles, a connecting beam, and anchor cables; the main piles and auxiliary piles are connected by the connecting beam to form an integral load-bearing structure, and the anchor cables are connected to the main piles and anchored to the foundation stable layer; the main piles and auxiliary piles are arranged horizontally along the direction of the center pile of the transmission line tower.

[0006] Furthermore, both the main pile and the auxiliary pile are cylindrical piles, and the diameter and length of the main pile are greater than those of the auxiliary pile; the connecting beam adopts a rectangular variable cross-section structure.

[0007] Furthermore, the diameter of the secondary pile is 0.5-0.7 times that of the main pile, and the length of the secondary pile is 0.5-0.7 times that of the main pile.

[0008] Furthermore, the center-to-center distance between the main pile and the auxiliary pile is 3-5 times the diameter of the main pile.

[0009] Furthermore, the connecting beam includes main reinforcement bars, inclined anchor bars, and a concrete protective layer. The main reinforcement bars are provided in multiple ways, and the multiple main reinforcement bars are arranged in a crisscross pattern to form a steel cage structure. The steel cage structure is provided with a concrete protective layer. The inclined anchor bars are anchored inside the main pile and the auxiliary pile.

[0010] Furthermore, the thickness of the concrete protective layer is not less than 30mm; the main reinforcement is HRB400 grade steel bar with a diameter of 18-32mm; the inclination angle of the inclined anchor bar relative to the horizontal plane is 45°-60°, and the anchorage length of the inclined anchor bar is not less than 35 times the diameter of the inclined anchor bar.

[0011] Furthermore, it also includes a concrete cushion layer, which is placed at the bottom of the connecting beam when the connecting beam is above the ground.

[0012] Furthermore, the top of the main pile is provided with anchor bolts and protective caps for connecting the tower legs. The anchor bolts are embedded in the concrete at the top of the main pile, and the protective caps cover the anchor bolts.

[0013] Furthermore, the main pile is provided with multiple sets of anchor cables at intervals along the height direction. Each anchor cable includes an anchor cable body, the anchoring section of which is anchored to the foundation stable layer, and the tensioning end of which is connected to the main pile through an anchor.

[0014] Furthermore, the diameter of the anchor cable body is 12.7-15.2mm; the length of the anchoring section is 5-8m and extends into the foundation stable layer by no less than 3m; the angle between the anchor cable and the axis of the main pile is 30°-45°.

[0015] The application of the technical solution of this utility model has the following beneficial effects: (1) This utility model provides a double-pile beam foundation with anchor cables, including main piles, secondary piles, a connecting beam, and anchor cables; the main piles and secondary piles are connected by the connecting beam to form an integral load-bearing structure, and the anchor cables are connected to the main piles and anchored to the stable foundation layer; the main piles and secondary piles are arranged horizontally along the direction of the central pile of the transmission line tower. This utility model can reduce the horizontal displacement of the foundation through the synergistic effect of the double piles and the connecting beam, and the addition of anchor cables further improves the tensile bearing capacity and overturning stability coefficient of the foundation, which can effectively resist extreme loads such as strong winds and earthquakes, and avoid pile uplift or overall overturning.

[0016] (2) In this utility model, compared with the traditional solution of increasing the pile length or pile diameter to improve the pull-out and lateral displacement resistance, the addition of anchor cables can reduce the main pile length, and the variable cross-section structure of the connecting beam design can save concrete usage, thereby reducing the overall material cost. Moreover, the anchor cable construction does not require expanding the construction area, and the construction cost is controllable.

[0017] (3) In this utility model, the connection between the connecting beam and the main pile and the auxiliary pile is enhanced by the inclined anchor bar, and the anchor cable and the main pile are rigidly connected by the anchor cable reserved hole and the anchor. The integrated structure of "pile-beam-anchor cable" is formed, which has strong stability and can adapt to the stress requirements under complex foundation conditions.

[0018] (4) Anchor cable construction can be carried out in coordination with the construction of main piles, secondary piles and connecting beams (anchor cable holes are reserved when the pile body is poured), without the need for additional complex equipment, and the construction efficiency is high.

[0019] (5) In this utility model, when the connecting beam is located above the ground, a concrete pad is provided to improve the durability and performance of the connecting beam.

[0020] In addition to the objectives, features, and advantages described above, this utility model has other objectives, features, and advantages. The present utility model will now be described in further detail with reference to the figures. Attached Figure Description

[0021] 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: Figure 1 This is a schematic diagram of the overall structure of the double-pile beam foundation with anchor cables in this utility model; Figure 2 This is a schematic diagram of the layout when using a double-pile beam foundation with anchor cables. Figure 3 This is a schematic diagram of the main pile structure; Figure 4 This is a schematic diagram of the secondary pile structure; Figure 5 This is a structural diagram showing the connection between the main piles, auxiliary piles, and connecting beams. Among them, 1. main pile, 11. anchor bolt, 12. protective cap, 2. secondary pile, 3. connecting beam, 31. main reinforcement, 32. inclined anchor reinforcement, 4. anchor cable, 5. concrete cushion layer. Detailed Implementation

[0022] The embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0023] In the description of this utility model, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "front", "back", "lateral", "longitudinal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this utility model.

[0024] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0025] Example: See Figures 1-5 This embodiment provides a double-pile beam foundation with anchor cables, including a main pile 1, an auxiliary pile 2, a connecting beam 3, and an anchor cable 4; the main pile 1 and the auxiliary pile 2 are connected by the connecting beam 3 to form an integral load-bearing structure, and the anchor cable 4 is connected to the main pile 1 and anchored to the foundation stable layer; the main pile 1 and the auxiliary pile 2 are arranged horizontally along the direction of the center pile of the transmission line tower.

[0026] In this embodiment, both the main pile 1 and the auxiliary pile 2 are cylindrical piles, and the diameter and length of the main pile 1 are greater than the diameter and length of the auxiliary pile 2. The diameter of main pile 1 is generally 1200-1800mm, and the pile length is determined according to geological conditions and load requirements, usually 8-15m. The diameter of auxiliary pile 2 is 0.5-0.7 times the diameter of main pile 1, usually 600-1200mm; the pile length of auxiliary pile 2 is 0.5-0.7 times the pile length of main pile 1, usually 4-10m; the specific parameters of auxiliary pile 2 can be determined by comprehensively considering the geological conditions of the tower site, load requirements, and economic efficiency.

[0027] The connecting beam 3 adopts a rectangular variable cross-section structure, with a cross-sectional width generally of 400-600mm. The cross-sectional height of the connection between the main pile 1 and the connecting beam 3, as well as the connection between the auxiliary pile 2 and the connecting beam 3, is greater than the cross-sectional height of the middle part of the connecting beam 3, so as to strengthen the connection strength between the main pile 1 and the connecting beam 3, and between the auxiliary pile 2 and the connecting beam 3.

[0028] In this embodiment, see Figure 5 The connecting beam 3 includes main reinforcement bars 31, inclined anchor bars 32, and a concrete protective layer. Multiple main reinforcement bars 31 are arranged in a crisscross pattern to form a steel cage structure. The main reinforcement bars 31 are HRB400 grade steel bars with a diameter of 18-32 mm. The steel cage structure is provided with a concrete protective layer with a thickness of not less than 30 mm. The inclined anchor bars 32 are anchored inside the main pile 1 and the auxiliary pile 2. The inclination angle of the inclined anchor bars 32 relative to the horizontal plane is 45°-60°, and the anchorage length of the inclined anchor bars 32 is not less than 35 times the diameter of the inclined anchor bars 32.

[0029] In this embodiment, the center-to-center distance between the main pile 1 and the auxiliary pile 2 is 3-5 times the diameter of the main pile 1 to ensure good collaborative performance.

[0030] It also includes a concrete cushion layer 5, which is placed at the bottom of the connecting beam 3 when the connecting beam 3 is above ground level, to improve the durability and performance of the connecting beam 3. In this embodiment, the thickness of the concrete cushion layer 5 is 80-100mm, and the concrete strength grade is not lower than C20.

[0031] In this embodiment, the main pile 1 is provided with multiple sets of anchor cables 4 at intervals along the height direction. Each anchor cable 4 includes an anchor cable body, the anchoring section of which is anchored to the foundation stable layer, and the tensioning end of the anchor cable body is connected to the main pile 1 through an anchor. In this embodiment, the top of the main pile 1 is provided with an anchor cable pre-drilled hole, the diameter of which is 20-30mm larger than the diameter of the anchor cable body to ensure that the anchor cable body can be smoothly inserted without affecting the structural strength of the pile. The anchor cable body is inserted into the main pile 1 and fixed by an anchor after tensioning is completed.

[0032] In this embodiment, to ensure load-bearing performance, the diameter of the anchor cable body is 12.7-15.2mm (tensile strength standard value 1860MPa); the length of the anchoring section is 5-8m and extends into the foundation stable layer by no less than 3m; the angle between the anchor cable 4 and the axis of the main pile 1 is 30°-45°.

[0033] See Figure 3 In this embodiment, the top of the main pile 1 is provided with anchor bolts 11 and protective caps 12 for connecting the tower legs. The anchor bolts 11 are embedded in the concrete at the top of the main pile 1. The anchor bolts 11 are of grade 5.6 or 8.8 and the diameter is usually 24-36mm. After the construction is completed, concrete protective caps 12 are poured on the top of the main pile 1 to protect the anchor bolts 11 and anchorages and prevent corrosion.

[0034] During the actual construction, a geological survey is first conducted to determine the parameters of the main piles and auxiliary piles; then the pile positions are laid out, and the main piles and auxiliary piles are constructed in sequence; after the pile concrete reaches the design strength, the connecting beams are constructed to ensure the anchorage quality of the main reinforcement and the inclined anchor bars; then the anchor cables are constructed; finally, the anchor bolts are installed and the protective caps are poured.

[0035] This utility model effectively improves the overall stiffness, lateral displacement resistance, and uplift and overturning resistance of the foundation through the synergistic effect of "piles-beams-anchor cables". It is particularly suitable for power transmission line tower foundation projects in soft soil foundations, collapsible loess areas, steep slopes and strong earthquake zones.

[0036] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A double-pile beam foundation with anchor cables, characterized in that, It includes a main pile (1), a secondary pile (2), a connecting beam (3) and an anchor cable (4); the main pile (1) and the secondary pile (2) are connected by the connecting beam (3) to form an integral load-bearing structure, and the anchor cable (4) is connected to the main pile (1) and anchored to the foundation stable layer; the main pile (1) and the secondary pile (2) are arranged horizontally along the direction of the center pile of the transmission line tower.

2. The double-pile beam foundation with anchor cables according to claim 1, characterized in that, Both the main pile (1) and the auxiliary pile (2) are cylindrical piles, and the diameter and length of the main pile (1) are greater than the diameter and length of the auxiliary pile (2); the connecting beam (3) adopts a rectangular variable cross-section structure.

3. A double-pile beam foundation with anchor cables according to claim 2, characterized in that, The diameter of the secondary pile (2) is 0.5-0.7 times the diameter of the main pile (1), and the length of the secondary pile (2) is 0.5-0.7 times the length of the main pile (1).

4. A double-pile beam foundation with anchor cables according to claim 2, characterized in that, The center-to-center distance between the main pile (1) and the secondary pile (2) is 3-5 times the diameter of the main pile (1).

5. A double-pile beam foundation with anchor cables according to claim 1, characterized in that, The connecting beam (3) includes main reinforcement (31), inclined anchor bars (32) and concrete protective layer. The main reinforcement (31) has multiple bars, which are arranged in a crisscross pattern to form a steel cage structure. The steel cage structure is provided with a concrete protective layer. The inclined anchor bars (32) are anchored inside the main pile (1) and the auxiliary pile (2).

6. A double-pile beam foundation with anchor cables according to claim 5, characterized in that, The thickness of the concrete protective layer is not less than 30mm; the main reinforcement (31) is HRB400 grade steel bar, and the diameter of the main reinforcement (31) is 18-32mm; the inclination angle of the inclined anchor bar (32) relative to the horizontal plane is 45°-60°, and the anchorage length of the inclined anchor bar (32) is not less than 35 times the diameter of the inclined anchor bar (32).

7. A double-pile beam foundation with anchor cables according to claim 5, characterized in that, It also includes a concrete cushion layer (5), which is placed at the bottom of the connecting beam (3) when the connecting beam (3) is above the ground.

8. A double-pile beam foundation with anchor cables according to claim 1, characterized in that, The top of the main pile (1) is provided with anchor bolts (11) and protective caps (12) for connecting the tower legs of the iron tower. The anchor bolts (11) are embedded in the concrete at the top of the main pile (1), and the protective caps (12) cover the anchor bolts (11).

9. A double-pile beam foundation with anchor cables according to any one of claims 1-8, characterized in that, The main pile (1) is provided with multiple sets of anchor cables (4) at intervals along the height direction. The anchor cable (4) includes an anchor cable body. The anchoring section of the anchor cable body is anchored to the foundation stable layer. The tensioning end of the anchor cable body is connected to the main pile (1) through an anchor.

10. A double-pile beam foundation with anchor cables according to claim 9, characterized in that, The diameter of the anchor cable body is 12.7-15.2mm; the length of the anchoring section is 5-8m and extends into the foundation stable layer by no less than 3m; the angle between the anchor cable (4) and the axis of the main pile (1) is 30°-45°.

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