A composite foundation for iron towers with short piles and inclined anchors and its construction method

Abstract

This invention relates to the field of tower foundation technology and discloses a composite foundation for a tower with short piles and inclined anchors, and its construction method. The foundation pit has a central pit at the bottom center, and several sets of side inclined pits are evenly distributed along the sides of the bottom of the foundation pit. Self-tensioning inclined anchor assemblies are installed within the side inclined pits. A central connecting frame between the tops of the self-tensioning inclined anchor assemblies is fixed with bolts. A positioning base assembly is installed within the foundation pit, positioned between the outer sides of the tops of the self-tensioning inclined anchor assemblies. A short pile steel reinforcement assembly is centrally located inside the positioning base assembly. All components of this invention can be prefabricated and then assembled on-site, improving construction efficiency and forming a unified structure with enhanced structural strength. The self-tensioning inclined anchor assemblies are anchored in the foundation, thereby bearing the horizontal load and uplift force transmitted from the tower, increasing the contact area between the foundation and the soil, better adapting to complex geological conditions, and improving the stability and bearing capacity of the foundation.

Description

Technical Field

[0001] This invention relates to the field of tower foundation technology, specifically to a composite foundation for a short pile and inclined anchor rod for a tower and its construction method. Background Technology

[0002] In the field of power engineering construction, the tower foundation, as a key structure supporting the transmission tower, directly affects the safe and stable operation of the transmission line. With the continuous expansion of power grid construction, transmission lines need to traverse areas with various complex geological conditions, such as mountainous terrain with thick soil layers and bedrock underneath, posing numerous challenges to traditional tower foundation designs.

[0003] Currently, commonly used tower foundations have limitations in resisting horizontal loads and uplift forces. When towers are subjected to external forces such as strong winds and earthquakes, the foundations are prone to displacement, tilting, or even overturning, seriously threatening the safety of transmission lines.

[0004] Meanwhile, existing construction methods for steel tower foundations suffer from low efficiency and poor structural integrity. They are highly susceptible to environmental factors, making it difficult to guarantee construction quality; the connection methods between components are not sufficiently optimized, leading to potential positional shifts during assembly and requiring subsequent repositioning, increasing construction difficulty; and stress concentration is prone to occur during long-term use, resulting in foundation structural damage and increased maintenance costs. To address these issues, we introduce a composite foundation for steel towers using short piles and inclined anchor bolts, along with its construction method. Summary of the Invention

[0005] The purpose of this invention is to provide a composite foundation for a short pile and inclined anchor rod for a steel tower and a construction method thereof, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A composite foundation for a short pile inclined anchor of a steel tower includes a foundation pit, a central pit at the bottom center of the foundation pit, and several sets of side inclined pits evenly distributed on the bottom side of the foundation pit.

[0008] The side inclined pit is equipped with a self-tensioning inclined anchor assembly. The middle connecting frame between the tops of the self-tensioning inclined anchor assembly is fixed with bolts. The foundation pit is equipped with a positioning base assembly that is locked between the tops of the self-tensioning inclined anchor assembly. The positioning base assembly is equipped with a short pile steel reinforcement assembly in the center. The bottom of the short pile steel reinforcement assembly passes through the middle connecting frame and extends into the central pit, and the top of the short pile steel reinforcement assembly extends out of the foundation pit.

[0009] Preferably, the bottom of the side sloping pit is inclined and extends downward along the outer side of the bottom of the foundation pit.

[0010] Preferably, the self-tensioning inclined anchor assembly includes a horn-shaped tensioning head extending into the side inclined pit, a reinforcing outer frame and a reinforcing inner frame fixed at the upper end of the horn-shaped tensioning head, and an inclined anchor member penetrating the horn-shaped tensioning head and the reinforcing inner frame;

[0011] The horn tensioning head includes a positioning frame, a horn-shaped clamping head separated by several groups of equally spaced slots at the bottom of the positioning frame, and a connecting cylinder centrally located at the top of the positioning frame.

[0012] The inclined anchor rod includes a tensioning head that is narrower at the top and wider at the bottom, and an inclined anchor rod connected to the top of the tensioning head. The top of the inclined anchor rod extends through the horn-shaped tensioning head and the reinforcing inner frame.

[0013] Preferably, the central connecting frame includes a central ring seat located on the outer side of the top of the central pit and inclined plates evenly spaced on the sides of the central ring seat, and the inclined plates are provided with rectangular slots;

[0014] The bottom of the inclined plate is close to the top of the reinforcing inner frame, and the inclined anchor rod extends through the corresponding rectangular slot. After the bolt and the inclined anchor rod are locked and fixed, the bolt is supported on the top of the inclined plate, and the tensioning head opens the horn-shaped clamping head, so that the horn-shaped clamping head is clamped on the inner wall of the side inclined pit.

[0015] Preferably, the outer surface of the trumpet-shaped clamping head is provided with several sets of clamping protrusions;

[0016] The reinforced outer frame includes several groups of circular reinforced outer steel bars distributed at equal intervals, and outer steel bar stirrups fixed at equal intervals to the outside of the several groups of reinforced outer steel bars.

[0017] The reinforcing steel bar is inserted into the corresponding positioning hole on the positioning frame;

[0018] The reinforced inner frame includes several groups of circular and equally spaced reinforcing inner bars, inner bar stirrups that are equally spaced and fixed to the outside of the several groups of reinforcing inner bars, and positioning discs that are fixed to the top of the several groups of reinforcing inner bars.

[0019] The inclined anchor rod extends through the reserved hole in the middle of the positioning plate, so that the reinforced inner frame is centrally positioned inside the reinforced outer frame.

[0020] Preferably, the positioning base assembly includes several sets of positioning ring seats arranged at equal intervals and side stirrups fixed at equal intervals to the outside of the several sets of positioning ring seats. The diameter of the positioning ring seats increases from top to bottom, and the positioning ring seats are engaged with the outside of the several sets of inclined anchor rods.

[0021] Preferably, the short pile reinforcement assembly includes several groups of circular short pile reinforcements distributed at equal intervals, inner stirrups fixed at equal intervals to the inner walls of the several groups of short pile reinforcements, and outer stirrups fixed at equal intervals to the outer walls of the several groups of short pile reinforcements.

[0022] Several sets of support arms are connected at equal intervals on the outer side of the top inner stirrup, and the support arms are fixed on the top positioning ring seat.

[0023] This invention also provides a construction method for a composite foundation of short piles and inclined anchors for iron towers, specifically including the following steps:

[0024] S1. Insert the self-tensioning inclined anchor assembly into the side inclined pit, and fix the middle connecting frame to the top of the self-tensioning inclined anchor assembly with bolts.

[0025] S2. Fix the short pile steel reinforcement assembly onto the positioning base assembly, and then hoist the positioning base assembly and the short pile steel reinforcement assembly as a whole, so that the positioning base assembly is stuck between the top and outer sides of the self-tensioning inclined anchor assembly, and the bottom of the short pile steel reinforcement assembly passes through the middle connecting frame and extends into the central pit in the middle.

[0026] S3. Then pour concrete into the foundation pit, side sloping pit and central pit, and wait for it to cure and set.

[0027] Compared with existing technologies, the beneficial effects of this invention are as follows: All components of this invention can be prefabricated and then assembled on-site, improving construction efficiency. The assembled components form a unified whole, enhancing structural strength. The overall strength and stiffness of the self-tensioning inclined anchor assembly are increased. Anchored in the foundation, the self-tensioning inclined anchor assembly can withstand the horizontal load and uplift force transmitted from the tower. The arrangement of several sets of self-tensioning inclined anchor assemblies increases the contact area between the foundation and the soil, better adapting to complex geological conditions and improving the stability and bearing capacity of the foundation. The bolt fixing not only achieves the connection between the self-tensioning inclined anchor assemblies but also provides support for the tensioning head of the self-tensioning inclined anchor assembly, ensuring the realization of the self-tensioning function.

[0028] The positioning base assembly is positioned between the top and outer sides of the self-tensioning inclined anchor assembly, providing positioning and constraint to prevent displacement during construction and stress. Furthermore, during the overall hoisting of the positioning base assembly and the short pile reinforcement assembly, it helps to position both, preventing overall tilting until the short pile reinforcement assembly is vertically and centered within the central pit. After bonding with the concrete, the positioning base assembly allows for better coordination with the inclined anchor and surrounding concrete. The positioning base assembly can form a stepped structure within the concrete, increasing the contact area and friction, resulting in a tighter connection between the positioning base assembly and the concrete, thus enhancing the overall integrity of the composite foundation structure. Attached Figure Description

[0029] Figure 1This is an exploded structural diagram of the overall assembly of the present invention;

[0030] Figure 2 This is a cross-sectional schematic diagram of the present invention after it has been installed and assembled in the soil layer during construction.

[0031] Figure 3 This is a three-dimensional structural diagram of the overall assembly of the present invention;

[0032] Figure 4 This is an exploded structural diagram of the self-tensioning inclined anchor bolt assembly of the present invention;

[0033] Figure 5 This is a schematic diagram of the inclined anchor rod of the present invention;

[0034] Figure 6 This is a schematic diagram of the structure of the horn tensioning head of the present invention;

[0035] Figure 7 This is an exploded structural diagram of the assembly of the reinforcing outer skeleton and the reinforcing inner skeleton of the present invention;

[0036] Figure 8 This is a three-dimensional structural schematic diagram of the self-tensioning inclined anchor bolt assembly of the present invention;

[0037] Figure 9 For the present invention Figure 8 A schematic diagram of the cross-sectional structure;

[0038] Figure 10 This is a three-dimensional structural diagram of the self-tensioning inclined anchor bolt assembly and the middle connecting frame of the present invention.

[0039] Figure 11 This is a three-dimensional structural diagram of the assembly of the positioning base component and the short pile reinforcement component of the present invention;

[0040] Figure 12 For the present invention Figure 11 A cross-sectional structural diagram.

[0041] In the diagram: 1. Self-tensioning inclined anchor bolt assembly; 101. Inclined anchor bolt component; 1011. Tensioning head; 1012. Inclined anchor bolt; 102. Horn-shaped tensioning head; 1021. Horn-shaped clamping head; 1022. Interval slot; 1023. Clamping protrusion; 1024. Positioning frame; 1025. Positioning hole; 1026. Connecting cylinder; 103. Reinforced outer frame; 1031. Reinforced outer steel bar; 1032. Outer steel bar stirrup; 104. Reinforced inner frame; 1041. Reinforced inner steel bar; 1042. Inner steel bar stirrup; 1043. Positioning plate;

[0042] 2. Middle connecting frame; 201. Middle ring seat; 202. Inclined plate; 203. Rectangular slot;

[0043] 3. Positioning base assembly; 301. Positioning ring seat; 302. Side stirrups;

[0044] 4. Short pile reinforcement assembly; 401. Short pile reinforcement; 402. External stirrups; 403. Internal stirrups; 404. Support arm;

[0045] 5. Bolts; 6. Foundation pit; 7. Side sloping pit; 8. Central pit. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] Example:

[0048] Please see Figure 1-12 The present invention provides a technical solution:

[0049] A composite foundation for a short pile inclined anchor of a steel tower includes a foundation pit 6, a central pit 8 at the bottom center of the foundation pit 6, and several sets of side inclined pits 7 evenly distributed on the bottom side of the foundation pit 6.

[0050] The bottom of the side sloping pit 7 is inclined and extends downward along the outer side of the bottom of the foundation pit 6.

[0051] The downward-sloping design of the side sloping pit 7 is compatible with the trumpet-shaped tensioning head 102 of the self-tensioning inclined anchor assembly 1. When the trumpet-shaped clamping head 1021 is opened, it can contact the inner wall of the side sloping pit 7 with a larger area, increasing friction and anchoring force, and improving the foundation's ability to resist horizontal loads and uplift forces. At the same time, this design makes the force transmission of the self-tensioning inclined anchor assembly 1 more uniform when under stress, reducing local stress concentration.

[0052] This design increases the contact area between the foundation and the soil, enabling it to better adapt to complex geological conditions and improve the stability and bearing capacity of the foundation.

[0053] A self-tensioning inclined anchor assembly 1 is installed in the side inclined pit 7;

[0054] I. Mechanical properties:

[0055] Uniform load distribution: The equally spaced self-tensioning inclined anchor assemblies 1 can evenly bear the load from the tower. After concrete pouring, the concrete bonds the various components into a whole. When the tower is subjected to vertical, horizontal, or uplift loads, these loads are evenly transferred to the surrounding soil through the equally spaced inclined anchor assemblies. This avoids local stress concentration, prevents foundation structure failure due to excessive local stress, and improves the overall bearing capacity and stability of the foundation.

[0056] Enhanced overturning resistance: The self-tensioning diagonal anchor components 1 cooperate with each other in the horizontal direction to jointly resist the overturning moment that the tower may generate. Their equidistant distribution ensures a relatively balanced overturning resistance force in all directions, and this balance is further strengthened after concrete pouring. The concrete connects the diagonal anchor components together, forming a stable structural system that effectively restricts the horizontal displacement and rotation of the foundation, greatly enhancing the overall overturning resistance of the structure.

[0057] Improved uplift resistance: The equally spaced self-tensioning inclined anchor components 1 work together to resist uplift forces. When the tower is subjected to uplift forces, each inclined anchor component transmits the force to the surrounding soil through its self-tensioning function. Due to their equal spacing, the uplift force can be evenly distributed to each component. After concrete pouring, the concrete further strengthens the connection between the self-tensioning inclined anchor components 1 and the soil, improving the overall uplift resistance and ensuring that the foundation will not fail when subjected to uplift forces.

[0058] II. Structural integrity:

[0059] Strengthening Structural Connections: After concrete pouring, the self-tensioning diagonal anchor components 1, distributed at equal intervals, fill the gaps between the components, tightly connecting them together. This connection method enhances the overall integrity of the structure, allowing the components to work together to form a unified load-bearing unit. The individual diagonal anchor components are no longer isolated entities, but rather cooperate through the bonding effect of the concrete, improving the overall stiffness and strength of the structure.

[0060] Reducing uneven settlement: Evenly spaced distribution helps ensure relatively uniform bearing capacity of the foundation at various locations. After concrete pouring, the concrete can play a certain regulating role, further reducing uneven settlement caused by differences in soil properties or uneven load distribution. Uniform settlement is crucial for the safe operation of the tower, avoiding problems such as tower tilting and deformation caused by uneven settlement, and extending the service life of the tower.

[0061] The self-tensioning inclined anchor assembly 1 includes a horn-shaped tensioning head 102 extending into the side inclined pit 7, a reinforcing outer frame 103 and a reinforcing inner frame 104 fixed at the upper end of the horn-shaped tensioning head 102, and an inclined anchor member 101 penetrating the horn-shaped tensioning head 102 and the reinforcing inner frame 104.

[0062] The horn tensioning head 102 includes a positioning frame 1024, a horn-shaped clamping head 1021 separated by several sets of equally spaced slots 1022 at the bottom of the positioning frame 1024, and a connecting cylinder 1026 centrally located at the top of the positioning frame 1024.

[0063] The inclined anchor rod 101 includes a tensioning head 1011 that is narrower at the top and wider at the bottom, and an inclined anchor rod 1012 connected to the top of the tensioning head 1011. The top of the inclined anchor rod 1012 extends through the horn-shaped tensioning head 102 and the reinforcing inner frame 104.

[0064] The structural design of the horn tensioning head 102 facilitates installation. The positioning frame 1024 and connecting cylinder 1026 can be quickly connected to the central connecting frame 2 and the inclined anchor rod 1012, reducing installation steps. The modular design of each component, such as the reinforced outer frame 103 and the reinforced inner frame 104, allows for pre-assembly, improving construction efficiency and shortening the construction period.

[0065] The outer surface of the trumpet-shaped clamping head 1021 is provided with several sets of clamping protrusions 1023;

[0066] The reinforced outer frame 103 includes several groups of circular and equally spaced reinforcing outer steel bars 1031 and external steel bar stirrups 1032 that are equally spaced and fixed to the outside of the several groups of reinforcing outer steel bars 1031.

[0067] The reinforcing steel bar 1031 is inserted into the corresponding positioning hole 1025 on the positioning frame 1024;

[0068] The reinforced inner frame 104 includes several sets of circular and equally spaced reinforcing inner bars 1041, inner bar stirrups 1042 that are equally spaced and fixed to the outside of the several sets of reinforcing inner bars 1041, and positioning discs 1043 that are fixed to the top of the several sets of reinforcing inner bars 1041.

[0069] The inclined anchor rod 1012 extends through the reserved hole in the middle of the positioning plate 1043, so that the reinforcing inner frame 104 is centrally positioned inside the reinforcing outer frame 103.

[0070] The outer reinforcing frame 103 and the inner reinforcing frame 104 are respectively composed of outer reinforcing bars 1031 and outer reinforcing bar stirrups 1032, and inner reinforcing bars 1041 and inner reinforcing bar stirrups 1042, which protect and strengthen the inclined anchor member 101, improving the overall strength and rigidity of the self-tensioning inclined anchor assembly 1. The outer reinforcing frame 103 is inserted into the positioning hole 1025 of the positioning frame 1024, and the inner reinforcing frame 104 positions the inclined anchor 1012 through the positioning plate 1043, ensuring that the self-tensioning inclined anchor assembly 1 can work together under stress, improving the reliability of the foundation.

[0071] In the self-tensioning inclined anchor bolt assembly 1, the inclined anchor bolt 101 passes through the horn-shaped tensioning head 102 and the reinforcing inner frame 104. When the bolt 5 is locked and fixed with the inclined anchor bolt 1012, the tensioning head 1011 on the inclined anchor bolt 101 moves upward and opens the horn-shaped clamping head 1021.

[0072] The clamping protrusion 1023 on the outside of the trumpet-shaped clamping head 1021 tightly clamps the inner wall of the side inclined pit 7. By utilizing the reaction force of the soil on the trumpet-shaped clamping head 1021, the self-tensioning inclined anchor rod assembly 1 is anchored in the foundation, thereby bearing the horizontal load and upward pull force transmitted from the iron tower.

[0073] The self-tensioning inclined anchor assembly 1 can adjust its parameters according to different geological conditions, such as changing the size of the trumpet-shaped clamping head 1021, the length and diameter of the inclined anchor 1012, etc., to adapt to different soil and rock properties. In soft soil layers or areas with fractured rock, the self-tensioning mechanism can provide stronger anchoring force, ensure foundation stability, and expand the application range of the foundation.

[0074] The reliable self-tensioning anchorage and stable structural design reduce the maintenance needs caused by anchorage failure or structural damage in the later stages of foundation operation. This component can operate effectively for a long time, reducing maintenance frequency and costs, and improving the economic efficiency and reliability of tower operation.

[0075] The middle connecting frame 2 between the tops of the self-tensioning inclined anchor bolt assembly 1 is fixed with bolts 5;

[0076] The middle connecting frame 2 includes a middle ring seat 201 located on the outer side of the top of the central pit 8 and inclined plates 202 evenly spaced on the side of the middle ring seat 201. The inclined plates 202 are provided with rectangular slots 203.

[0077] The bottom of the inclined plate 202 is close to the top of the reinforcing inner frame 104, and the inclined anchor rod 1012 extends through the corresponding rectangular slot 203. After the bolt 5 is locked and fixed to the inclined anchor rod 1012, the bolt 5 is supported on the top of the inclined plate 202, and the tensioning head 1011 opens the horn-shaped clamping head 1021, so that the horn-shaped clamping head 1021 is clamped on the inner wall of the side inclined pit 7.

[0078] The central connecting frame 2 not only connects the self-tensioning inclined anchor rod assembly 1, but also positions and supports the short pile reinforcement assembly 4, ensuring the accurate relative position of each assembly in space and making the stress distribution of the entire foundation structure more reasonable. Furthermore, the bolts 5 are locked and fixed to the top of the inclined plate 202, further enhancing the reliability of the connection. That is, by fixing with bolts 5, not only is the connection between the self-tensioning inclined anchor rod assemblies 1 achieved, but support is also provided for the tensioning head 1011, ensuring the realization of the self-tensioning function.

[0079] The foundation pit 6 is equipped with a positioning base assembly 3 that is locked between the top and outer sides of the self-tensioning inclined anchor assembly 1;

[0080] The positioning base assembly 3 includes several sets of positioning ring seats 301 arranged at equal intervals at the top and bottom, and side stirrups 302 fixed at equal intervals on the outside of the several sets of positioning ring seats 301. The diameter of the positioning ring seats 301 increases from top to bottom. The positioning ring seats 301 are locked on the outside of the several sets of inclined anchor rods 1012.

[0081] The diameter of the positioning ring seat 301 of the positioning base assembly 3 increases sequentially from top to bottom. It is locked on the outside of the inclined anchor rod 1012 and can position and constrain the self-tensioning inclined anchor rod assembly 1 to prevent it from shifting during construction and under stress. Furthermore, when the positioning base assembly 3 and the short pile steel reinforcement assembly 4 are hoisted as a whole, it can position both of them to prevent them from tilting as a whole, until the short pile steel reinforcement assembly 4 is vertical and inserted into the central pit 8 in a centered position.

[0082] The positioning ring seat 301 is locked on the outside of the inclined anchor rod 1012, which can accurately position the inclined anchor rod 1012, ensuring that the inclined anchor rod 1012 maintains the correct position during the concrete solidification process, preventing it from shifting or shaking, thereby ensuring the stability and accuracy of the entire composite foundation structure.

[0083] The diameter of the positioning ring seat 301 increases sequentially from top to bottom. This design, when combined with concrete, allows the positioning base assembly 3 to work better in conjunction with the inclined anchor rod 1012 and the surrounding concrete. The positioning ring seats 301 of different diameters can form a step-like structure in the concrete, increasing the contact area and friction with the concrete, making the connection between the positioning base assembly 3 and the concrete tighter, thereby enhancing the integrity of the entire composite foundation structure.

[0084] When the composite foundation is subjected to external forces, the positioning ring seat 301 can gradually disperse the force borne by the inclined anchor rod 1012 into the surrounding concrete through ring seats of different diameters, avoiding stress concentration. This can improve the load-bearing capacity of the composite foundation, enabling the structure to better withstand various loads transmitted from the tower and extend the service life of the foundation.

[0085] The short pile reinforcement assembly 4 is fixed to the topmost positioning ring seat 301 of the positioning base assembly 3 by the support arm 404, which ensures the verticality and stability of the short pile reinforcement assembly 4.

[0086] The positioning base assembly 3 and the short pile reinforcement assembly 4 work together to enable the foundation to evenly transfer the force to the foundation soil when it is subjected to vertical loads, thereby improving the bearing capacity of the foundation.

[0087] The positioning base component 3 has a short pile steel reinforcement component 4 centrally located inside;

[0088] The short pile reinforcement assembly 4 includes several groups of circular short pile reinforcement 401 distributed at equal intervals, inner stirrups 403 fixed at equal intervals to the inner wall of the several groups of short pile reinforcement 401, and outer stirrups 402 fixed at equal intervals to the outer wall of the several groups of short pile reinforcement 401.

[0089] Several sets of support arms 404 are connected at equal intervals on the outer side of the top inner stirrup 403, and the support arms 404 are fixed on the top positioning ring seat 301.

[0090] The bottom of the short pile steel reinforcement assembly 4 passes through the middle connecting frame 2 and extends into the central pit 8, while the top of the short pile steel reinforcement assembly 4 extends out of the foundation pit 6.

[0091] Under the load of the iron tower, the short pile steel reinforcement assembly 4 bears the vertical load and transfers it to the foundation soil at the bottom of the central pit 8; the self-tensioning inclined anchor assembly 1 bears the horizontal load and the upward pull force, and transfers the force to the deep soil through the interaction with the soil and concrete in the side inclined pit 7; the central connecting frame 2 plays the role of connecting and fixing the components, ensuring that the force can be effectively transferred between the components, so that the entire foundation forms a coordinated whole.

[0092] Concrete is poured into the foundation pit 6, the side inclined pit 7, and the central pit 8. After curing, the concrete encapsulates and bonds the self-tensioning inclined anchor assembly 1, the central connecting frame 2, the positioning base assembly 3, and the short pile reinforcement assembly 4 into a single unit. The concrete encapsulation enhances the stability and integrity of each component, further improving the foundation's load-bearing capacity and deformation resistance, enabling the foundation to better adapt to various load conditions of the tower.

[0093] Enhanced structural stability: The short pile steel reinforcement assembly 4 penetrates the central connecting frame 2 and extends into the central pit 8, enabling the short pile steel reinforcement assembly 4 to form a tighter connection with the central connecting frame 2 and the concrete around the central pit 8, so as to jointly bear the load transmitted from the iron tower, improve the overall stability of the foundation structure, and reduce the possibility of uneven settlement.

[0094] Improved load-bearing capacity: This configuration allows the short pile steel reinforcement assembly 4 to better exert its tensile and compressive strength, effectively transferring the load of the tower to the depth of the foundation, thereby improving the foundation's load-bearing capacity, enabling it to withstand greater external forces and weight, and ensuring the safe operation of the tower under various working conditions.

[0095] Enhancing overall collaborative performance: The short pile reinforcement assembly 4 interacts with the concrete in the central connecting frame 2 and the central pit 8 to form a unified load-bearing system. After the concrete has solidified, the bonding force and mechanical interlocking force between them enable the components to work together to resist external forces, thereby improving the integrity and seismic performance of the foundation structure.

[0096] Optimized stress distribution: This allows the load to be distributed more evenly throughout the foundation structure, avoiding stress concentration. The short pile reinforcement assembly 4 extends centrally into the central pit 8, helping to balance forces in all directions, reducing the risk of structural failure due to excessive local stress, and extending the foundation's service life.

[0097] Complementary load transfer: The short pile reinforcement assembly 4 primarily transfers the vertical load of the tower directly to the depth of the foundation, enhancing the vertical bearing capacity of the foundation; while the self-tensioning inclined anchor assembly 1, while bearing the vertical load, focuses more on resisting horizontal and uplift loads. The combination of these two components allows for a more rational load transfer in all directions, effectively improving the foundation's ability to withstand complex loads and preventing foundation damage caused by a single component's inability to fully cope with multiple loads.

[0098] Enhancing overall stability: The short pile reinforcement assembly 4 penetrates the central connecting frame 2 and extends into the central pit 8, stabilizing the central structure of the foundation; the self-tensioning inclined anchor assemblies 1 are evenly distributed around the perimeter, reinforcing the foundation from all sides. Together, these two components effectively support the foundation structure from the center to the perimeter, enhancing overall stability and reducing the possibility of uneven settlement and structural deformation.

[0099] Synergistic Resistance to External Forces: When subjected to external forces, the short pile reinforcement assembly 4 and the self-tensioning inclined anchor assembly 1 can work together. For example, when encountering horizontal external forces such as earthquakes, the self-tensioning inclined anchor assembly 1 can first resist part of the horizontal force through its own tensioning effect. At the same time, the short pile reinforcement assembly 4 will also participate in resisting horizontal displacement due to its bond with the concrete. The two work together to improve the seismic performance of the foundation. When subjected to uplift forces, the self-tensioning characteristics of the self-tensioning inclined anchor assembly 1 play a major role, while the short pile reinforcement assembly 4 can also provide a certain amount of uplift resistance through its interaction with the surrounding concrete, jointly ensuring the safety of the foundation.

[0100] Optimized stress distribution: The rational arrangement of the short pile reinforcement assembly 4 and the self-tensioning inclined anchor assembly 1 can make the stress distribution inside the foundation more uniform. The short pile reinforcement assembly 4 adjusts the stress in the central area, while the self-tensioning inclined anchor assembly 1 optimizes the stress in the surrounding area, avoiding stress concentration and thus improving the durability and reliability of the foundation structure.

[0101] This invention also provides a construction method for a composite foundation of short piles and inclined anchors for iron towers, specifically including the following steps:

[0102] S1. Insert the self-tensioning inclined anchor bolt assembly 1 into the side inclined pit 7. The self-tensioning inclined anchor bolt assembly 1 needs to be prefabricated in advance and slide into the side inclined pit 7 along the inner wall of the side inclined pit 7.

[0103] Then, the middle connecting frame 2 is fixed to the top of the self-tensioning inclined anchor rod assembly 1 with bolts 5, that is, the middle connecting frame 2 is hoisted into the foundation pit 6, and at the same time, the top of the inclined anchor rod 1012 extends through the corresponding rectangular slot 203 until the inclined anchor rod 1012 abuts against the outermost end of the rectangular slot 203. At this time, the middle ring seat 201 sits at the bottom of the foundation pit 6. Finally, the bolts 5 are locked and fixed to the inclined anchor rod 1012.

[0104] S2. Fix the short pile steel reinforcement assembly 4 on the positioning base assembly 3, and then hoist the positioning base assembly 3 and the short pile steel reinforcement assembly 4 as a whole, so that the positioning base assembly 3 is stuck between the top outer side of the self-tensioning inclined anchor assembly 1 (that is, the positioning ring seat 301 is stuck between the outer side of several sets of inclined anchors 1012), and the bottom of the short pile steel reinforcement assembly 4 passes through the middle connecting frame 2 and extends into the central pit 8 in the center.

[0105] S3. Then pour concrete into the foundation pit 6, the side sloping pit 7 and the central pit 8. When pouring concrete, it is necessary to ensure that it is poured continuously in one go. It is also necessary to pour in layers with a thickness of 0.5m.

[0106] Concrete can be poured simultaneously for the side sloping pit 7 and the central pit 8, and finally the foundation pit 6 can be poured.

[0107] During the pouring process, an immersion vibrator should be used to ensure thorough compaction.

[0108] After pouring and curing, the top of the short pile reinforcement 401 extends out of the concrete. The flange at the bottom of the tower is locked to the top of the short pile reinforcement 401 with a stainless steel nut. The top of the short pile reinforcement 401 has an external thread that can be screwed into the stainless steel nut.

[0109] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A composite foundation for a steel tower with short piles and inclined anchors, comprising a foundation pit, characterized in that: The bottom of the foundation pit has a central pit in the center, and the bottom sides of the foundation pit have several sets of side sloping pits distributed at equal intervals. The side inclined pit is equipped with a self-tensioning inclined anchor assembly. The middle connecting frame between the tops of the self-tensioning inclined anchor assembly is fixed with bolts. The foundation pit is equipped with a positioning base assembly that is locked between the tops of the self-tensioning inclined anchor assembly. The positioning base assembly is equipped with a short pile steel reinforcement assembly in the center. The bottom of the short pile steel reinforcement assembly passes through the middle connecting frame and extends into the central pit, and the top of the short pile steel reinforcement assembly extends out of the foundation pit. The self-tensioning inclined anchor assembly includes a horn-shaped tensioning head extending into the side inclined pit, a reinforcing outer frame and a reinforcing inner frame fixed at the upper end of the horn-shaped tensioning head, and an inclined anchor member penetrating the horn-shaped tensioning head and the reinforcing inner frame. The horn tensioning head includes a positioning frame, a horn-shaped clamping head separated by several groups of equally spaced slots at the bottom of the positioning frame, and a connecting cylinder centrally located at the top of the positioning frame. The inclined anchor rod includes a tensioning head that is narrower at the top and wider at the bottom, and an inclined anchor rod connected to the top of the tensioning head. The top of the inclined anchor rod extends through the horn-shaped tensioning head and the reinforcing inner frame.

2. The composite foundation for a short pile inclined anchor bolt for a steel tower according to claim 1, characterized in that: The bottom of the side sloping pit is inclined and extends downward along the outer side of the bottom of the foundation pit.

3. The composite foundation for a short pile inclined anchor bolt for a steel tower according to claim 1, characterized in that: The central connecting frame includes a central ring seat located on the outer side of the top of the central pit and inclined plates equally spaced on the sides of the central ring seat, and the inclined plates are provided with rectangular slots; The bottom of the inclined plate is close to the top of the reinforcing inner frame, and the inclined anchor rod extends through the corresponding rectangular slot. After the bolt and the inclined anchor rod are locked and fixed, the bolt is supported on the top of the inclined plate, and the tensioning head opens the horn-shaped clamping head, so that the horn-shaped clamping head is clamped on the inner wall of the side inclined pit.

4. The composite foundation for a short pile inclined anchor bolt for a steel tower according to claim 1, characterized in that: The outer surface of the trumpet-shaped clamping head is provided with several sets of clamping protrusions; The reinforced outer frame includes several groups of circular reinforced outer steel bars distributed at equal intervals, and outer steel bar stirrups fixed at equal intervals to the outside of the several groups of reinforced outer steel bars. The reinforcing steel bar is inserted into the corresponding positioning hole on the positioning frame; The reinforced inner frame includes several groups of circular and equally spaced reinforcing inner bars, inner bar stirrups that are equally spaced and fixed to the outside of the several groups of reinforcing inner bars, and positioning discs that are fixed to the top of the several groups of reinforcing inner bars. The inclined anchor rod extends through the reserved hole in the middle of the positioning plate, so that the reinforced inner frame is centrally positioned inside the reinforced outer frame.

5. A composite foundation for a short pile inclined anchor bolt for a steel tower according to claim 1, characterized in that: The positioning base assembly includes several sets of positioning ring seats arranged at equal intervals and side stirrups fixed at equal intervals to the outside of the several sets of positioning ring seats. The diameter of the positioning ring seats increases from top to bottom. The positioning ring seats are engaged with the outside of the several sets of inclined anchor rods.

6. A composite foundation for a steel tower with short piles and inclined anchors according to claim 5, characterized in that: The short pile reinforcement assembly includes several groups of circular short pile reinforcements distributed at equal intervals, inner stirrups fixed at equal intervals to the inner walls of the several groups of short pile reinforcements, and outer stirrups fixed at equal intervals to the outer walls of the several groups of short pile reinforcements. Several sets of support arms are connected at equal intervals on the outer side of the top inner stirrup, and the support arms are fixed on the top positioning ring seat.

7. A construction method for a composite foundation for a steel tower with short piles and inclined anchors as described in any one of claims 1-6, characterized in that: Specifically, the following steps are included: S1. Insert the self-tensioning inclined anchor assembly into the side inclined pit, and fix the middle connecting frame to the top of the self-tensioning inclined anchor assembly with bolts. S2. Fix the short pile steel reinforcement assembly onto the positioning base assembly, and then hoist the positioning base assembly and the short pile steel reinforcement assembly as a whole, so that the positioning base assembly is stuck between the top and outer sides of the self-tensioning inclined anchor assembly, and the bottom of the short pile steel reinforcement assembly passes through the middle connecting frame and extends into the central pit in the middle. S3. Then pour concrete into the foundation pit, side sloping pit and central pit, and wait for it to cure and set.

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