Main material insertion type stepped bearing platform rock anchor rod foundation structure

Abstract

The utility model discloses a main material insertion type stepped bearing platform rock anchor rod foundation structure, which relates to the technical field of power transmission line foundation engineering, and comprises an insertion type tower leg main material, an inclined upright post and stepped bearing platforms which are arranged in a graded manner along the terrain gradient direction, and the top of a bottom rock anchor rod is anchored in the stepped bearing platforms; the top of the lateral anchor rod is anchored on the inclined stand column, the lower portion of the lateral anchor rod is embedded in a bedrock layer through a bottom anchor rod anchoring body, the top of the lateral anchor rod is anchored on the inclined stand column, and the lower portion of the lateral anchor rod is embedded in the bedrock layer through a lateral anchor rod anchoring body. The excellent bearing performance of the bed rock is fully utilized, mountainous area slope topography is adapted to the maximum extent, the rock mass excavation depth and the earthwork volume are effectively reduced, the construction difficulty is reduced, and the construction efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of power transmission line foundation engineering technology, and in particular to a main material insert-type stepped pier rock anchor foundation structure. Background Technology

[0002] For mountain transmission line projects, rock anchor foundations are preferred for tower sites with good bedrock properties, shallow burial depth, and terrain slope ≤30°. Conventional rock anchor foundations require square pile caps, which often result in large excavation depths and earthwork volumes on the inner side of the mountain to meet the bottom embedment depth requirements. This is not suitable for the actual mountain slope terrain, resulting in a large amount of foundation engineering and significant environmental damage.

[0003] In the prior art, a short pile rock anchor composite foundation disclosed in patent publication number CN222614231U includes a foundation pit for pouring short piles and an anchor hole for inserting anchor rods. The inner wall of the foundation pit is provided with a boss, which is used to support a positioning plate. The positioning plate is provided with a limiting hole for a drill rod to pass through. The drill rod is used to form the anchor hole from the foundation pit downwards. The anchor rod is inserted into the foundation pit and the anchor hole. The anchor rod foundation in this comparative technology cannot adapt to the load-bearing capacity in complex environments. Utility Model Content

[0004] The purpose of this utility model is to solve the problem that existing anchor foundation structures cannot adapt to the complex terrain and geological environment of mountainous areas and have poor load-bearing capacity. This utility model adopts a stepped foundation, with the bottom designed in a stepped manner according to the slope of the terrain. Rock anchors are set at the bottom and lateral anchors are set on the sides of the columns, which makes the overall load-bearing capacity better. This utility model provides a main material insert-type stepped foundation rock anchor foundation structure.

[0005] A further objective of this invention is to address the instability of existing anchor foundation structures. This invention provides a higher-performance main material insert-type stepped pier rock anchor foundation structure by setting end anchor plates and stiffening ribs.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a main material insertable stepped pier rock anchor foundation structure, including insertable tower leg main material and inclined column, as well as stepped pier arranged in stages along the terrain slope direction, the bottom rock anchor is anchored at the top in the stepped pier, and the lower part is embedded in the bedrock layer by the bottom anchor anchor body, the lateral anchor is anchored at the top in the inclined column, and the lower part is embedded in the bedrock layer by the lateral anchor anchor body.

[0007] Preferably, angle steel anchors are arranged at equal intervals along the depth direction on the main material of the insertable tower leg, and the angle steel anchors are fixed by connecting bolts.

[0008] As a preferred option, an end anchor plate is arranged at the end of the main material of the insert-type tower leg, and several stiffening ribs are provided on the end anchor plate.

[0009] Preferably, the inclination angle of the inclined column and the main material of the inserted tower leg should be consistent with the angle of the upper tower leg. The bottom of the stepped foundation should be embedded in the bedrock layer. The number of steps at the bottom of the stepped foundation should correspond to the number of rows of bottom rock anchors. The height of each step should be the same. The depth of the outermost step embedded in the bedrock layer should not be less than 0.5m.

[0010] Preferably, the bottom rock anchors are arranged at equal intervals, the anchor hole spacing should not be less than 3.0 to 4.0 times the anchor hole diameter, and the net spacing should not be less than 160 mm; the lateral anchors are arranged horizontally or inclined.

[0011] Preferably, the bottom rock anchor and the lateral anchor are made of ribbed steel bars or high-strength steel bars, and the tops are anchored in the stepped foundation and the inclined column, respectively, with the tops bent.

[0012] Preferably, the main material of the insert-type tower leg is the same as that of the main material of the upper tower leg, and is anchored to the lower part of the stepped foundation in terms of depth.

[0013] Preferably, the load borne by the angle steel anchor should not be less than 70% of the total foundation load, and the length of a single angle steel anchor should be the same as the leg width of the insert-type tower leg main member.

[0014] As a preferred option, the arrangement of angle steel anchors should meet the minimum spacing requirements. The distance between the uppermost angle steel anchor and the top surface of the foundation column should not be less than 8 times its leg width, and the spacing between each layer of angle steel anchors should not be less than 3 times its leg width and should be arranged at equal intervals.

[0015] As a preferred option, the stepped foundation and inclined columns are cast-in-place reinforced concrete structures, and the spacing of the internal reinforcing bars near the angle steel anchors and end anchor plates is adjustable.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model adopts a stepped foundation, with the bottom designed in a stepped manner according to the terrain slope. Rock anchors are set at the bottom and lateral anchors are set on the sides of the columns. This makes full use of the excellent bearing capacity of the bedrock, adapts to the mountainous sloping terrain to the greatest extent, effectively reduces the depth of rock excavation and the amount of earthwork, reduces construction difficulty, improves construction efficiency, and reduces environmental disturbance.

[0017] This invention employs inclined columns in conjunction with insertable tower legs to directly transfer the load from the upper tower. Lateral anchors on the columns limit horizontal displacement, improving the foundation's resistance to horizontal bearing capacity. The stress state of the foundation columns, pile caps, and bottom anchors is effectively improved. Angle steel anchors are evenly spaced along the depth direction on the insertable tower legs, with end anchors at the ends, significantly enhancing the pull-out resistance of the insertable main members and preventing upward pull-out failure. Through the coordinated work of these components, the foundation structure has a clear stress path, a reasonable stiffness distribution, and effectively reduces the overall foundation workload, making it suitable for various complex terrain and geological conditions. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model.

[0019] Figure 2 for Figure 1 Enlarged view of point C in the middle.

[0020] Figure 3 This is a schematic diagram of the end anchor plate structure of this utility model.

[0021] In the diagram: 1. Inserted tower leg main material; 2. Angle steel anchor; 3. End anchor plate; 4. Lateral anchor; 5. Lateral anchor body; 6. Inclined column; 7. Stepped pier; 8. Bottom rock anchor; 9. Bottom anchor body; 10. End anchor plate; 11. Stiffening rib; 12. Connecting bolt; 13. Foundation soil layer; 14. Bedrock layer. Detailed Implementation

[0022] The technical solution of this utility model will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings. The described embodiments are only some embodiments of this utility model, and not all embodiments.

[0023] Example 1: Refer to Figures 1 to 3 A stepped, insert-type rock anchor foundation structure is disclosed. This structure comprises insert-type tower leg main members 1 and inclined columns 6. The insert-type tower leg main members 1 run through the entire foundation structure. At the bottom of the foundation structure, stepped foundations 7 are arranged in stages along the terrain slope. This stepped design cleverly adapts to the undulating terrain, allowing the foundation to better conform to the natural landform, reducing earthwork, and providing an ideal platform for anchor placement. Bottom rock anchors 8 are embedded in the bedrock layer 14 from bottom rock anchor anchor bodies 9, and anchored at the top within the stepped foundations 7, tightly connected to the foundations to form a stable support system. Lateral anchors 4 are anchored at the top within the inclined columns 6, and their lower parts are embedded in the bedrock layer 14 through lateral anchor anchor bodies 5, providing lateral restraint to the tower foundation and enhancing the overall overturning resistance.

[0024] Angle steel anchors 2 are evenly spaced along the depth direction on the main member 1 of the insert-type tower leg. These angle steel anchors 2 are fixed by connecting bolts 12 to ensure a tight connection between the main member and the surrounding structure. At the end of the main member 1 of the insert-type tower leg, end anchor plates 10 and stiffening ribs 11 are arranged and connected by welding to further enhance the anchoring performance at the end.

[0025] The tilt angles of the inclined columns 6 and the insert-type tower leg main members 1 have been calculated to maintain a consistent angle with that of the upper tower leg, ensuring smooth force transmission. The bottom of the stepped foundation 7 is embedded in the bedrock layer 14, and the number of steps at the bottom, following the terrain slope, precisely corresponds to the number of rows of bottom rock anchors 8. This correspondence makes the anchor arrangement more reasonable and the stress distribution more uniform. The height of each step is designed to be the same, ensuring the regularity and stability of the structure. The depth of the outermost step embedded in the bedrock layer 14 must not be less than 0.5m to ensure sufficient embedment depth and stability. At the same time, the horizontal thickness of the bedrock layer outside the base surface of the outermost step has also been carefully calculated to ensure that it can meet the requirements of horizontal shear bearing capacity, so that the foundation structure can remain stable under horizontal loads and will not slip or fail.

[0026] The number of bottom rock anchors 8 is not arbitrarily determined, but rather based on precise calculations of the foundation's vertical uplift bearing capacity. To ensure the anchors' load-bearing performance and construction feasibility, the bottom rock anchors 8 should be arranged at equal intervals. The anchor hole spacing is designed with full consideration of the mutual influence and stress characteristics between anchors, stipulating that the anchor hole spacing should not be less than 3.0 to 4.0 times the anchor hole diameter, and the net spacing should not be less than 160 mm to prevent stress interference and construction collisions between anchors. Lateral anchors 4 can be flexibly arranged horizontally or inclined according to the actual terrain and load requirements. Their main function is to meet the foundation's horizontal bearing capacity and overall overturning stability requirements. By rationally arranging the lateral anchors 4, the foundation depth can be effectively reduced, thereby significantly reducing the amount of earthwork excavation and reinforced concrete work, bringing considerable economic benefits to the project. For tower types with large loads, such as corner towers and spanning towers, the horizontal load resistance of the foundation can be improved by further increasing the number of lateral anchors 4, ensuring load-bearing safety and meeting the stability requirements of these special tower types under complex stress conditions.

[0027] Regarding the selection of anchor materials, ribbed steel bars or high-strength steel bars can be used for the bottom rock anchor 8 and the lateral anchor 4. These materials have high strength and good anchoring performance, which can meet the requirements of the foundation structure for the anchor bearing capacity. The top of the anchor is anchored in the stepped foundation 7 and the inclined column 6 respectively, and a bent arrangement is adopted. This bent design can effectively increase the bonding area between the anchor and the concrete, thereby significantly improving the pull-out performance of the anchor and ensuring that the anchor will not be pulled out from the anchoring point under stress, thus ensuring the long-term stability of the foundation structure. The anchoring length of the anchor embedded in the bedrock layer has been calculated and verified in detail and should be determined to be 3-8m, and must not be less than the structural length requirement in various types of bedrock layers to ensure the anchoring reliability of the anchor in the bedrock. In particular, when the foundation soil layer 13 is thick, the lateral anchor 4 can be anchored with anchor cables, which can effectively anchor the anchor in the lower bedrock. This can not only effectively improve the horizontal bearing capacity of the foundation, but also significantly reduce the construction difficulty. The anchor cable is made of high-strength steel strand, which has high strength and good corrosion resistance, and can play a stable anchoring role for a long time.

[0028] The design of the insert-type tower leg main member 1 also fully considers its coordination with the superstructure. Its specifications should be consistent with those of the upper tower leg main member, so that it can be directly anchored to the lower part of the stepped foundation 7 in the depth direction. The anchoring depth should meet the minimum depth requirement of the inserted angle steel embedded in the concrete to ensure a reliable connection between the insert-type tower leg main member 1 and the foundation, so that it can fully play its role in transferring loads.

[0029] Regarding the design of angle steel anchors 2, their quantity is determined through precise calculation based on the foundation load and the bearing capacity of a single angle steel anchor. To fully utilize the role of the angle steel anchors, it is stipulated that the load borne by the angle steel anchors should not be less than 70% of the total foundation load. This ensures that the angle steel anchors play a dominant role in the foundation structure and can effectively transfer the foundation load to the surrounding soil and rock. The concrete compressive stress on a single angle steel anchor 2 can be assumed to satisfy a right-angled trapezoidal distribution pattern. Based on this assumption, its bearing capacity can be accurately calculated and determined, thus providing a scientific basis for the design of the angle steel anchors. At the same time, the length of a single angle steel anchor is carefully designed, preferably the same as the leg width of the insert-type tower leg main member 1. This design ensures a tight fit between the angle steel anchors and the tower leg main member, improves the overall integrity and load-bearing performance of the structure, ensures the safety and reliability of the foundation structure under various loads, and provides a solid guarantee for the stable operation of the tower.

[0030] Example 2: Refer to Figures 1 to 3A stepped, main-material-inserted rock anchor foundation structure is described. At the bottom of the foundation, stepped foundations 7 are arranged in stages along the terrain slope, allowing the foundation to better conform to the natural topography and reduce earthwork. The bottom of the stepped foundations 7 is deeply embedded in the bedrock layer 14. The number of steps at the bottom, following the terrain slope, precisely corresponds to the number of rows of bottom rock anchors 8. This correspondence makes the anchor arrangement more rational and the stress distribution more uniform. The height of each step is carefully designed to be the same, ensuring the regularity and stability of the structure. The depth of the outermost step embedded in the bedrock layer 14 is rigorously considered and must not be less than 0.5m to ensure sufficient embedment depth and stability. Simultaneously, the horizontal thickness of the bedrock layer beyond the outermost step's base surface is also carefully calculated to ensure it meets the requirements of horizontal shear bearing capacity, thus ensuring the foundation structure remains stable under horizontal loads and does not slip or fail.

[0031] The bottom rock anchor 8 is embedded in the bedrock layer 14 through the bottom rock anchor anchor body 9, and the top is anchored in the stepped foundation 7, tightly connected with the foundation to form a stable support system. The lateral anchor 4 is anchored in the inclined column 6 at the top, and its lower part is embedded in the bedrock layer 14 through the lateral anchor anchor body 5, providing lateral restraint for the tower foundation and enhancing the overall anti-overturning capacity.

[0032] The number of bottom rock anchors 8 is not arbitrarily determined, but rather based on precise calculations of the foundation's vertical uplift bearing capacity. To ensure the anchor's stress performance and construction feasibility, the bottom rock anchors 8 should be arranged at equal intervals. The design of the anchor hole spacing fully considers the mutual influence and stress characteristics between anchors, stipulating that the anchor hole spacing should not be less than 3.0 to 4.0 times the anchor hole diameter, and the net spacing should not be less than 160 mm to prevent stress interference and construction collisions between anchors.

[0033] Lateral anchors 4 can be flexibly arranged horizontally or inclined according to the actual terrain and stress requirements. Their main function is to meet the requirements of the foundation's horizontal bearing capacity and overall anti-overturning stability. By rationally arranging lateral anchors 4, the foundation depth can be effectively reduced, thereby significantly reducing the amount of earthwork excavation and reinforced concrete work, bringing considerable economic benefits to the project construction. For high-load tower types such as corner towers and spanning towers, the number of lateral anchors 4 can be further increased to improve the foundation's horizontal load resistance, ensuring load-bearing safety and adapting to the stability requirements of these special tower types under complex stress conditions.

[0034] Regarding the selection of anchor materials, ribbed steel bars or high-strength steel bars can be used for the bottom rock anchor 8 and the lateral anchor 4. These materials have high strength and good anchoring performance, which can meet the requirements of the foundation structure for the anchor bearing capacity. The top of the anchor is anchored in the stepped foundation 7 and the inclined column 6 respectively, and a bent arrangement is adopted. This bent design can effectively increase the bonding area between the anchor and the concrete, thereby significantly improving the pull-out resistance of the anchor and ensuring that the anchor will not be pulled out from the anchoring point under stress, thus ensuring the long-term stability of the foundation structure. The anchoring length of the anchor embedded in the bedrock layer has been calculated and verified in detail and should be determined to be 3 to 8 m, and must not be less than the structural length requirements of various bedrock layers to ensure the anchoring reliability of the anchor in the bedrock.

[0035] When the foundation soil layer 13 is relatively thick, the lateral anchor bolts 4 can be anchor cables, which are effectively anchored to the underlying bedrock. This not only effectively improves the horizontal bearing capacity of the foundation but also significantly reduces the difficulty of construction. The anchor cables are made of high-strength steel strand, which has high strength and good corrosion resistance, and can play a stable anchoring role for a long time.

[0036] Angle steel anchors 2 are evenly spaced along the depth direction of the insert-type tower leg main member 1. These angle steel anchors 2 are fixed by connecting bolts 12, ensuring a tight connection between the main member and the surrounding structure. At the ends of the insert-type tower leg main member 1, end anchor plates 10 and stiffening ribs 11 are arranged and connected by welding, further strengthening the anchoring performance at the ends and making the anchoring system of the entire structure more robust and reliable. The specifications of the insert-type tower leg main member 1 should be consistent with those of the upper tower leg main member, so that it can be directly anchored to the lower part of the stepped foundation 7 in the depth direction. The anchoring depth must meet the minimum depth requirement for the inserted angle steel to be embedded in the concrete, ensuring a reliable connection between the insert-type tower leg main member 1 and the foundation, so that it can fully play its role in transferring loads.

[0037] The angle steel anchor 2 is precisely calculated based on the foundation load and the bearing capacity of a single angle steel anchor. To fully utilize the role of the angle steel anchor, it is stipulated that the load borne by the angle steel anchor should not be less than 70% of the total foundation load. This ensures that the angle steel anchor plays a dominant role in the foundation structure and can effectively transfer the foundation load to the surrounding soil and rock. The concrete compressive stress on a single angle steel anchor 2 can be assumed to satisfy a right-angled trapezoidal distribution pattern. Based on this assumption, its bearing capacity can be accurately calculated and determined, thus providing a scientific basis for the design of the angle steel anchor. At the same time, the length of a single angle steel anchor should preferably be the same as the leg width of the insert-type tower leg main member 1. This design can ensure a tight fit between the angle steel anchor and the tower leg main member, improve the integrity and stress performance of the structure, ensure the safety and reliability of the foundation structure under various loads, and provide a solid guarantee for the stable operation of the tower.

[0038] The tilt angles of the inclined column 6 and the insert-type tower leg main member 1 are precisely calculated to maintain a consistent angle with the upper tower leg, ensuring smooth force transmission. This design not only improves the structural load-bearing performance but also ensures the overall aesthetics and harmony of the tower. Through careful design and reasonable layout, this foundation structure can adapt to various complex terrain conditions while meeting the stability and load-bearing capacity requirements of the tower under different working conditions.

[0039] The distance between the topmost angle steel anchor and the top surface of the foundation column 6 is specifically stipulated to be no less than 8 times its leg width. This design aims to ensure the uniformity of stress distribution in this area and avoid stress concentration problems caused by excessively small spacing. Furthermore, the spacing between each layer of angle steel anchors is also explicitly stipulated to be no less than 3 times its leg width, and an equal-spaced arrangement is recommended to ensure the integrity and stability of the structure, while also facilitating precise installation during construction.

[0040] For the connecting bolt 12 of the angle steel anchor, its load-bearing capacity design needs to comprehensively consider both shear and compressive conditions, taking the smaller value of the two as the design standard for the load-bearing capacity of a single bolt. This design consideration is to ensure the reliability of the connection and avoid structural failure due to overload of a single load-bearing capacity. The number of connecting bolts needs to be determined based on detailed calculations to ensure that it can meet the load-bearing requirements of the foundation structure in actual use.

[0041] When the foundation columns are short and the number of angle steel anchors is insufficient, end anchor plates 3 are introduced to supplement the load-bearing capacity. When installing end anchor plates 3, verification must be performed according to the structural requirements for stiffening flanges to ensure that the end anchor plates 3 and their connected stiffening ribs 11 have sufficient load-bearing capacity. Simultaneously, the local compressive bearing capacity of the foundation concrete within the area of ​​action of the end anchor plates must be verified to prevent concrete failure due to excessive local pressure, ensuring the reliability and durability of the structure.

[0042] The stepped foundation 7 and inclined columns 6 are constructed using cast-in-place reinforced concrete. This structural form not only provides good integrity and compressive strength but also allows for flexible design based on actual stress conditions. The spacing of the internal reinforcing bars near the angle steel anchors 2 and end anchor plates 10 can be adjusted appropriately. This design optimization aims to balance construction convenience with structural performance, ensuring that the reinforcement arrangement meets design requirements while facilitating on-site operations by construction personnel.

[0043] For those skilled in the art, the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention.

Claims

1. A main material insert-type stepped pier rock anchor foundation structure, characterized in that, It includes the main material of the inserted tower leg and the inclined column, as well as the stepped foundation arranged in stages along the slope of the terrain. The top of the bottom rock anchor is anchored in the stepped foundation, and the lower part is embedded in the bedrock layer by the bottom anchor body. The top of the lateral anchor is anchored to the inclined column, and the lower part is embedded in the bedrock layer by the lateral anchor body.

2. The main material insert-type stepped pier rock anchor foundation structure according to claim 1, characterized in that, Angle steel anchors are arranged at equal intervals along the depth direction on the main material of the insert-type tower leg, and the angle steel anchors are fixed by connecting bolts.

3. A main material insert-type stepped pier rock anchor foundation structure according to claim 1 or 2, characterized in that, The main body of the insert-type tower leg is equipped with end anchor plates, and several stiffening ribs are provided on the end anchor plates.

4. A main material insert-type stepped pier rock anchor foundation structure according to claim 1 or 2, characterized in that, The inclination angle of the inclined columns and the main material of the inserted tower legs should be consistent with the angle of the upper tower legs. The bottom of the stepped foundation should be embedded in the bedrock layer. The number of steps at the bottom should correspond to the number of rows of bottom rock anchors, and the height of each step should be the same. The depth of the outermost step embedded in the bedrock layer should not be less than 0.5m.

5. The main material insert-type stepped pier rock anchor foundation structure according to claim 4, characterized in that, Bottom rock anchors should be arranged at equal intervals, with the anchor hole spacing not less than 3.0 to 4.0 times the anchor hole diameter, and the net spacing not less than 160 mm; lateral anchors should be arranged horizontally or inclined.

6. A main material insert-type stepped pier rock anchor foundation structure according to claim 1 or 5, characterized in that, The bottom rock anchors and lateral anchors are made of ribbed steel bars or high-strength steel bars, and are anchored at the top in the stepped foundation and inclined column, respectively, with the tops bent.

7. A main material insert-type stepped pier rock anchor foundation structure according to claim 1 or 5, characterized in that, The main material of the insert-type tower leg is the same as that of the main material of the upper tower leg, and it is anchored to the lower part of the stepped foundation in terms of depth.

8. The main material insert-type stepped pier rock anchor foundation structure according to claim 2, characterized in that, The load borne by the angle steel anchor should not be less than 70% of the total foundation load, and the length of a single angle steel anchor should be the same as the leg width of the main material of the inserted tower leg.

9. A main material insert-type stepped pier rock anchor foundation structure according to claim 8, characterized in that, The arrangement of angle steel anchors should meet the minimum spacing requirements. The distance between the uppermost angle steel anchor and the top surface of the foundation column should not be less than 8 times its leg width. The spacing between each layer of angle steel anchors should not be less than 3 times its leg width and should be arranged at equal intervals.

10. A main material insert-type stepped pier rock anchor foundation structure according to claim 8 or 9, characterized in that, The stepped foundation and inclined columns are cast-in-place reinforced concrete structures, and the spacing of the internal reinforcing bars near the angle steel anchors and end anchor plates is adjustable.

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