Parameter determination method of cable-stayed anchor pile foundation and cable-stayed anchor pile foundation

Abstract

The application provides a parameter determination method and a cable-stayed anchor pile foundation, and the method comprises the following steps: obtaining a preset anchor plate diameter and a preset pile end soil penetration depth of the cable-stayed anchor pile foundation, and a pile foundation inclination and other foundation structure parameters of the cable-stayed anchor pile foundation; obtaining a pull-out ultimate bearing capacity of the cable-stayed anchor pile foundation under the conditions of the preset anchor plate diameter and the pile end soil penetration depth according to the preset anchor plate diameter, the preset pile end soil penetration depth, the pile foundation inclination and the other foundation structure parameters; obtaining a preset uplift force acting on the cable-stayed anchor pile foundation; performing compliance determination on the preset anchor plate diameter and the preset pile end soil penetration depth according to the size relationship between the preset uplift force and the pull-out ultimate bearing capacity, and obtaining target parameters of the cable-stayed anchor pile foundation. The scheme of the application meets the use requirements of the flexible photovoltaic support cable-stayed foundation, reduces the material consumption and cost, and can accurately determine the parameters of the cable-stayed anchor pile foundation, thereby facilitating the selection and construction.

Description

Technical Field

[0001] This invention relates to the field of new energy technology, and in particular to a method for determining the parameters of a cable-stayed anchor pile foundation and the cable-stayed anchor pile foundation itself. Background Technology

[0002] As photovoltaic power plant construction expands into complex terrains such as mountains and hills, flexible photovoltaic (PV) supports are widely used due to their advantages such as large span, lightweight design, and strong terrain adaptability. The cable-stayed foundation, as the core load-bearing component of the flexible PV support, must withstand the enormous tensile force transmitted by the cables, and its ultimate tensile strength directly determines the stability of the support system. Currently, two main technical solutions are used for the cable-stayed foundations of flexible PV supports: one is the cast-in-place pile foundation, which involves drilling holes on-site, placing a reinforcing cage, and pouring concrete to form piles. The ultimate tensile strength is provided by the side friction between the pile and the surrounding soil, making it suitable for various geological conditions, but the construction process is complex and time-consuming; the other is the pipe pile foundation, which uses precast prestressed concrete pipe piles, driven by hammering or static pressure, relying on the friction between the pile and the soil for load-bearing capacity. This method has higher construction efficiency than cast-in-place pile foundations, but its adaptability to geological conditions is poor. Summary of the Invention

[0003] This invention provides a method for determining the parameters of a cable-stayed anchor pile foundation and the cable-stayed anchor pile foundation itself. Under the premise of reducing the diameter of the steel pipe of the pile body, it ensures that the ultimate tensile bearing capacity meets the usage requirements of the cable-stayed foundation of the flexible photovoltaic support, thereby reducing material usage and cost. At the same time, it can accurately determine the parameters of the cable-stayed anchor pile foundation, which facilitates selection and construction.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: A method for determining parameters of a cable-stayed anchor pile foundation includes: Obtain the preset anchor plate diameter and preset pile tip penetration depth of the inclined anchor pile foundation, as well as the pile foundation inclination angle and other foundation structure parameters of the inclined anchor pile foundation; Based on the preset anchor plate diameter, preset pile tip depth, pile foundation inclination angle and other foundation structure parameters, the pull-out ultimate bearing capacity of the inclined anchor pile foundation under the preset anchor plate diameter and preset pile tip depth is obtained. Obtain the preset pull-out force acting on the inclined anchor pile foundation; Based on the relationship between the preset pull-out force and the ultimate tensile bearing capacity, the preset anchor plate diameter and preset pile tip penetration depth are determined to meet compliance requirements, thereby obtaining the target parameters of the inclined anchor pile foundation; the target parameters include the anchor plate diameter and the pile tip penetration depth.

[0005] Optionally, based on the preset anchor plate diameter, preset pile tip penetration depth, pile foundation inclination angle, and other foundation structure parameters, the ultimate pull-out bearing capacity of the inclined anchor pile foundation under the preset anchor plate diameter and preset pile tip penetration depth conditions is obtained, including: Based on the preset anchor plate diameter, preset pile tip penetration depth, pile foundation inclination angle and other foundation structure parameters, the soil self-weight above the failure surface of the cylindrical pile body, the soil self-weight between the failure surfaces of the cylindrical pile body and the cohesion on the failure surface of the soil are obtained. The frictional force on the soil failure surface is obtained based on the self-weight of the soil above the failure surface of the cylindrical pile and the self-weight of the soil between the failure surface of the cylindrical pile. Based on the cohesion, friction, and the soil self-weight between the failure surfaces of the cylindrical pile body and the soil, the ultimate pull-out bearing capacity of the inclined anchor pile foundation under the conditions of the preset anchor plate diameter and the preset pile tip insertion depth is obtained.

[0006] Optionally, the frictional force on the soil failure surface is obtained based on the self-weight of the soil above the failure surface of the cylindrical pile and the self-weight of the soil between the failure surfaces of the cylindrical pile, including: The normal component of the soil weight is obtained based on the soil weight above the failure surface of the cylindrical pile and the soil weight between the failure surface of the cylindrical pile. Obtain the internal friction angle of the soil; The frictional force on the soil failure surface is obtained based on the internal friction angle and the normal component.

[0007] Optionally, based on the cohesion, friction, and the self-weight of the soil between the failure surfaces of the cylindrical pile body and the soil, the ultimate pull-out bearing capacity of the inclined anchor pile foundation under the conditions of the preset anchor plate diameter and the preset pile tip insertion depth is obtained, including: Based on the cohesion, friction, and the self-weight of the soil between the failure surfaces of the cylindrical pile and the soil, the formula is used to... The ultimate pull-out bearing capacity of the inclined anchor pile foundation under the conditions of the preset anchor plate diameter and the preset pile tip insertion depth is obtained; wherein, For the ultimate tensile strength, The self-weight of the soil between the failure surfaces of the cylindrical pile body and the soil body. For the inclination angle of the pile foundation, For friction, It represents cohesive force.

[0008] Optionally, based on the relationship between the preset pull-out force and the ultimate tensile bearing capacity, the diameter of the preset anchor plate and the preset pile tip penetration depth are determined to meet compliance requirements, thereby obtaining the target parameters of the inclined anchor pile foundation, including: The safety factor is obtained based on the relationship between the preset pull-out force and the ultimate pull-out bearing capacity. When the safety factor is greater than or equal to the preset threshold, the compliance determination of the preset anchor plate diameter and the preset pile tip penetration depth is passed, and the target parameters are obtained based on the preset anchor plate diameter and the preset pile tip penetration depth. When the safety factor is less than a preset threshold, the compliance determination of the preset anchor plate diameter and the preset pile tip penetration depth is determined to be unsuccessful. The values ​​of the preset anchor plate diameter and the preset pile tip penetration depth are increased. The pull-out ultimate bearing capacity is re-determined based on the increased anchor plate diameter and pile tip penetration depth, and a compliance determination is made. When the compliance determination is passed, the target parameters are obtained.

[0009] The present invention also provides a inclined anchor pile foundation, comprising: Cylindrical pile body; A pile tip welded to the first end of the cylindrical pile body; A pile top flange welded to the second end of the cylindrical pile body, wherein a plurality of bolt holes are evenly provided on the pile top flange; Diagonal tie rods that are bolted to the pile top flange through the plurality of bolt holes; An anchor plate is installed on the side of the cylindrical pile near the first end. The anchor plate is spirally wrapped around the outer surface of the cylindrical pile and welded to the cylindrical pile. The parameters of the inclined anchor pile foundation are determined by the method described above.

[0010] Optionally, the pile tip is conical, and a spiral blade is welded to the outer surface of the pile tip.

[0011] Optionally, during the construction of the inclined anchor pile foundation, the plurality of bolt holes are fixedly connected to the pile foundation spinning device.

[0012] Optionally, the anchor plate has a ring-shaped structure, and the diameter of the outer ring of the anchor plate is larger than the diameter of the cylindrical pile body.

[0013] Optionally, the height between the upper and lower bottom surfaces of the cylindrical pile body is greater than the diameter of the circular cross-section of the cylindrical pile body.

[0014] The above-described solution of the present invention has at least the following beneficial effects: The above-described solution of the present invention obtains the preset anchor plate diameter and preset pile tip embedment depth of the inclined anchor pile foundation, as well as the pile foundation inclination angle and other foundation structure parameters; based on the preset anchor plate diameter, preset pile tip embedment depth, pile foundation inclination angle, and other foundation structure parameters, it obtains the ultimate tensile bearing capacity of the inclined anchor pile foundation under the preset anchor plate diameter and preset pile tip embedment depth conditions; it obtains the preset upward pull-out force acting on the inclined anchor pile foundation; based on the relationship between the preset upward pull-out force and the ultimate tensile bearing capacity, it performs a compliance determination on the preset anchor plate diameter and preset pile tip embedment depth to obtain the target parameters of the inclined anchor pile foundation; the target parameters include the anchor plate diameter and the pile tip embedment depth. This allows for a reduction in the diameter of the pile steel pipe while ensuring that the ultimate tensile bearing capacity meets the usage requirements of the inclined anchor pile foundation for flexible photovoltaic supports, reducing material usage and cost; simultaneously, it allows for accurate determination of the parameters of the inclined anchor pile foundation, facilitating selection and construction. Attached Figure Description

[0015] Figure 1 This is a flowchart of the parameter determination method for the inclined anchor pile foundation according to an embodiment of the present invention; Figure 2 This is a longitudinal cross-sectional view of the bearing capacity of the method for determining the parameters of the inclined anchor pile foundation according to an embodiment of the present invention; Figure 3 This is a cross-sectional schematic diagram of the bearing capacity of the method for determining the parameters of the inclined anchor pile foundation according to an embodiment of the present invention; Figure 4 This is a structural diagram of the inclined anchor pile foundation according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the pile top flange of the inclined anchor pile foundation according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the anchor plate of the inclined anchor pile foundation according to an embodiment of the present invention; Explanation of reference numerals in the attached figures: 1. Cylindrical pile body; 2. Pile tip; 3. Pile top flange; 31. Bolt hole; 4. Diagonal tie rod; 5. Anchor plate; 6. Ground. Detailed Implementation

[0016] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0017] like Figure 1 As shown, an embodiment of the present invention proposes a method for determining the parameters of a cable-stayed anchor pile foundation, including: Step 11: Obtain the preset anchor plate diameter and preset pile tip penetration depth of the inclined anchor pile foundation, as well as the pile foundation inclination angle and other foundation structure parameters of the inclined anchor pile foundation. Here, as Figure 2 As shown, the anchor plate 5 is arranged around the cylindrical pile body 1, as... Figure 3 As shown, the preset anchor plate diameter is the diameter of the outermost end of anchor plate 5, denoted as D. The preset pile tip penetration depth is the length of the centerline of the pile from anchor plate 5 to the ground surface, denoted as L. The pile foundation inclination angle is the angle between the centerline of the cylindrical pile and the horizontal direction, denoted as β. Other foundation structural parameters include: the diameter d of the cylindrical pile.

[0018] Step 12: Based on the preset anchor plate diameter, preset pile tip penetration depth, pile foundation inclination angle and other foundation structure parameters, obtain the ultimate pull-out bearing capacity of the inclined anchor pile foundation under the preset anchor plate diameter and preset pile tip penetration depth conditions. Here, the soil weight γ, soil cohesion c, and soil internal friction angle are obtained based on general geological exploration tests. By combining the pre-assigned preset anchor plate diameter and preset pile tip penetration depth, along with the designed pile foundation inclination angle and other structural parameters, the ultimate tensile bearing capacity is calculated to obtain the ultimate tensile bearing capacity of the inclined anchor pile foundation under the pre-assigned preset anchor plate diameter and preset pile tip penetration depth conditions. The ultimate tensile bearing capacity consists of three parts: the self-weight of the cylindrical soil on the anchor plate, the frictional force of the soil failure surface, and the cohesion of the soil failure surface. Through precise calculation and superposition of these three forces, the ultimate tensile bearing capacity of the inclined anchor pile foundation is scientifically determined.

[0019] Step 13: Obtain the preset pull-out force acting on the inclined anchor pile foundation; Here, as Figure 2 As shown, the upward pull-out force acts on the tie rod 4 of the inclined anchor pile foundation, applying an upward force to the inclined anchor pile foundation. The preset upward pull-out force is determined according to the specific application scenario of the inclined anchor pile foundation, and is the upward pull-out force that the inclined anchor pile foundation may experience during actual use.

[0020] Step 14: Based on the relationship between the preset pull-out force and the ultimate tensile bearing capacity, determine the compliance of the preset anchor plate diameter and the preset pile tip penetration depth to obtain the target parameters of the inclined anchor pile foundation; the target parameters include the anchor plate diameter and the pile tip penetration depth.

[0021] Here, the calculated ultimate tensile bearing capacity and preset pull-out force are preliminarily verified, a safety factor is calculated, and the compliance of the preliminary preset values ​​(preset anchor plate diameter and preset pile tip embedment depth) is determined based on the safety factor. If the compliance determination is passed, it indicates that the values ​​of the preset anchor plate diameter and preset pile tip embedment depth meet the usage requirements, and construction can proceed according to these values ​​for the corresponding usage scenario. If the compliance determination fails, the values ​​of the preset anchor plate diameter and preset pile tip embedment depth need to be adjusted to pass the compliance determination.

[0022] This embodiment of the invention provides a method for determining the parameters of a cable-stayed anchor pile foundation specifically adapted to the inclined-stayed foundation of flexible photovoltaic systems, and conforming to the structural characteristics of "small pile diameter and large anchor plate". It clarifies the source of the ultimate tensile bearing capacity of this type of cable-stayed anchor pile foundation, fully considering the contribution of the self-weight of the cylindrical soil on the anchor plate and the friction and cohesion of the soil failure surface to the tensile strength, establishing a comprehensive and scientific calculation system for the ultimate tensile bearing capacity; improving the accuracy of the calculation of the ultimate tensile bearing capacity of the cable-stayed anchor pile foundation of flexible photovoltaic systems and the accuracy of determining the parameter values ​​of the cable-stayed anchor pile foundation, facilitating the structural selection and construction of the cable-stayed anchor pile foundation, providing a reliable basis for photovoltaic power station engineering design, ensuring the stable operation of flexible photovoltaic systems; promoting the standardized application of cable-stayed anchor pile foundations with "small pile diameter and large anchor plate" in flexible photovoltaic systems, optimizing engineering costs, and promoting the efficient development of the photovoltaic new energy industry.

[0023] In an optional embodiment of the present invention, step 12, based on the preset anchor plate diameter, preset pile tip penetration depth, pile foundation inclination angle, and other foundation structure parameters, obtaining the ultimate pull-out bearing capacity of the inclined anchor pile foundation under the preset anchor plate diameter and preset pile tip penetration depth conditions, may include: Step 121: Based on the preset anchor plate diameter, preset pile tip penetration depth, pile foundation inclination angle and other foundation structure parameters, obtain the soil self-weight above the cylindrical pile body soil failure surface, the soil self-weight between the cylindrical pile body soil failure surfaces, and the cohesion on the soil failure surface. Here, as Figure 2 As shown, the soil failure surface is the soil interface corresponding to the cylindrical trajectory formed by the outer edge of the anchor plate 5 during the rotary driving process of the inclined anchor pile foundation. This interface represents the relative deformation or failure of the soil during the pull-out process. The soil failure surface is cylindrical, as shown in... Figure 2 In the sectional view shown, the generatrix on the shorter side of the soil failure surface is denoted as the generatrix on the soil failure surface. The generatrix of the longer side of the soil failure surface is denoted as the lower generatrix of the soil failure surface. The soil above the failure surface of the cylindrical pile is as follows: Figure 2The soil in the triangular region shown (i.e., the area with a triangular cross-section formed by the generatrix of the ground surface and the soil failure surface) has a self-weight of the soil above the failure surface of the cylindrical pile body, denoted as . The soil between the failure surfaces of the cylindrical pile body and the soil is as follows: Figure 2 The soil within the failure surface of the cylindrical soil body between the upper and lower generatrices shown, and the self-weight of the soil body between the failure surfaces of the cylindrical pile body, is denoted as . .

[0024] Specifically, the self-weight of the soil above the failure surface of the cylindrical pile. ,in, Generatrix on the soil failure surface D is the inclination angle of the pile foundation, and D is the diameter of the anchor plate. The soil weight is [not specified].

[0025] The self-weight of the soil between the failure surfaces of the cylindrical pile body Where d is the diameter of the cylindrical pile body, L represents the lower generatrix of the soil failure surface, and L represents the depth of the pile tip into the soil.

[0026] The cohesion at the soil failure surface , where c is the cohesion of the soil, in kPa.

[0027] Step 122: Based on the self-weight of the soil above the failure surface of the cylindrical pile and the self-weight of the soil between the failure surfaces of the cylindrical pile, the frictional force on the failure surface of the soil is obtained. Specifically, step 122 may include: Step 1221: Based on the soil self-weight above the failure surface of the cylindrical pile and the soil self-weight between the failure surface of the cylindrical pile, the normal component of the soil self-weight is obtained. Here, the normal components of the soil's self-weight in the direction of the uplift force are respectively and .

[0028] Step 1222: Obtain the internal friction angle of the soil; Step 1223: Based on the internal friction angle and normal component, obtain the frictional force on the soil failure surface.

[0029] Here, the frictional force on the soil failure surface ,in, The internal friction angle of the soil.

[0030] Step 123: Based on the cohesion, friction, and the soil self-weight between the failure surfaces of the cylindrical pile body and the soil, obtain the ultimate pull-out bearing capacity of the inclined anchor pile foundation under the conditions of the preset anchor plate diameter and the preset pile end insertion depth.

[0031] Specifically, steps 123 may include: Step 1231: Based on the cohesion, friction, and the self-weight of the soil between the failure surfaces of the cylindrical pile body and the soil, using the formula... The ultimate pull-out bearing capacity of the inclined anchor pile foundation under the conditions of the preset anchor plate diameter and the preset pile tip insertion depth is obtained; wherein, For the ultimate tensile strength, The self-weight of the soil between the failure surfaces of the cylindrical pile body and the soil body. For the inclination angle of the pile foundation, For friction, It represents cohesive force.

[0032] In an optional embodiment of the present invention, step 14, based on the relationship between the preset pull-out force and the ultimate pull-out bearing capacity, determines the compliance of the preset anchor plate diameter and the preset pile tip insertion depth to obtain the target parameters of the inclined anchor pile foundation, which may include: Step 141: Obtain the safety factor based on the relationship between the preset pull-out force and the ultimate pull-out bearing capacity; The safety factor Where N is the preset upward pulling force.

[0033] Step 142: When the safety factor is greater than or equal to the preset threshold, the compliance determination of the preset anchor plate diameter and the preset pile end penetration depth is passed, and the target parameters are obtained based on the preset anchor plate diameter and the preset pile end penetration depth. Here, when the safety factor is greater than the preset threshold, it means that the preset anchor plate diameter and the preset pile tip penetration depth can meet the safety requirements under the preset pull-out force conditions. Then, the preset anchor plate diameter and the preset pile tip penetration depth are determined as the target anchor plate diameter and the target pile tip penetration depth.

[0034] Step 143: When the safety factor is less than the preset threshold, the compliance determination of the preset anchor plate diameter and the preset pile tip penetration depth is determined to be unsuccessful. The values ​​of the preset anchor plate diameter and the preset pile tip penetration depth are increased. The pull-out ultimate bearing capacity is re-determined based on the increased anchor plate diameter and pile tip penetration depth, and a compliance determination is made. When the compliance determination is passed, the target parameters are obtained.

[0035] Here, if the safety factor is less than the preset threshold, it means that the preset anchor plate diameter and the preset pile tip penetration depth cannot meet the requirements of the preset pull-out force. Therefore, it is necessary to increase the anchor plate diameter and the pile tip penetration depth to meet the safety requirements under the preset pull-out force scenario.

[0036] This invention provides a parameter determination method for inclined anchor pile foundations, establishing a calculation model for the ultimate tensile bearing capacity of inclined anchor pile foundations adapted to special structures. It organically combines anchor plate size, embedment depth, and soil mechanical parameters (natural unit weight, friction coefficient, cohesion) to achieve precise quantification of the ultimate tensile bearing capacity, specifically matching the tensile requirements of flexible photovoltaic (PV) systems. This provides a dedicated and scientific method for determining the ultimate tensile bearing capacity of inclined anchor pile foundations for flexible PV systems. It fully integrates the triple tensile forces of cylindrical soil self-weight, failure surface friction, and cohesion, resulting in a more comprehensive calculation logic and results that better reflect the actual tensile capacity of the inclined anchor piles in flexible PV systems, providing a reliable basis for engineering design. Through scientific calculation methods, it fully releases the tensile advantages of the "small pile body, large anchor plate" structure, avoiding conservative waste in engineering design while ensuring the stable operation of flexible PV systems. The inclined anchor pile foundation supported by this invention does not require additional increase in pile size; high ultimate tensile bearing capacity can be achieved through large anchor plates, significantly reducing material usage and construction difficulty, and optimizing the cost of PV power plant projects.

[0037] like Figure 4 As shown, an embodiment of the present invention also provides a cable-stayed anchor pile foundation, comprising: Cylindrical pile body 1; A pile tip 2 is welded to the first end of the cylindrical pile body 1; A pile top flange 3 is welded to the second end of the cylindrical pile body 1, and a plurality of bolt holes 31 are evenly provided on the pile top flange 3; The diagonal tie rod 4 is bolted to the pile top flange 3 through the plurality of bolt holes 31; An anchor plate 5 is installed on the side of the cylindrical pile body 1 near the first end. The anchor plate 5 is spirally wrapped around the outer surface of the cylindrical pile body 1 and welded and fixed to the cylindrical pile body 1. The parameters of the inclined anchor pile foundation are determined by the method described above.

[0038] The pile tip 2 is conical, and a spiral blade is welded to the outer surface of the pile tip 2.

[0039] During the construction of the inclined anchor pile foundation, the plurality of bolt holes 31 are fixedly connected to the pile foundation spinning device.

[0040] like Figure 6 As shown, the anchor plate 5 has a circular ring structure, and the diameter of the outer ring of the anchor plate 5 is larger than the diameter of the cylindrical pile body 1.

[0041] The height between the upper and lower bottom surfaces of the cylindrical pile body 1 is greater than the diameter of the circular cross-section of the cylindrical pile body 1.

[0042] In this embodiment, the pile tip 2 adopts a conical structure with spiral blades welded to the outside; the material is the same steel as the cylindrical pile body 1, and it is fixedly connected to the lower end of the cylindrical pile body 1 by welding. The pile tip 2 can achieve precise positioning of the pile foundation, and during the rotary pile driving process, the spiral blades rotate and squeeze the soil, providing guidance and driving force for the pile body to sink, reducing the pile driving resistance.

[0043] The anchor plate 5 is made of helical pile steel plate and is fixedly installed at the end of the cylindrical pile body 1 (near the pile tip 2). It is set perpendicular to the cylindrical pile body 1 and welded to it. The weld must meet the shear strength requirements. The anchor plate 5 is a circular structure, and its diameter can be adjusted according to the specific application scenario. Its core function is to provide the main pull-out ultimate bearing capacity. The bearing mechanism is as follows: when the foundation is subjected to an upward tensile force, the anchor plate will drive the cylindrical soil on it to be stressed synchronously. The cylindrical soil and the foundation soil will form a failure surface. The friction at the failure surface provides the pull-out ultimate bearing capacity. At the same time, the self-weight of this part of the soil also provides the foundation pull-out force.

[0044] The cylindrical pile body 1 serves as the core component connecting the pile top flange 3 and the anchor plate 5. Its functions are twofold: first, to transmit the tension of the flexible photovoltaic support tie rod to the anchor plate 5; and second, to transmit the torque of the pile driver to the pile tip 2 during the rotary pile driving process, ensuring the smooth rotation and sinking of the pile. The two ends of the cylindrical pile body 1 are welded and fixed to the pile top flange 3 and the anchor plate 5, respectively.

[0045] like Figure 5 As shown, the pile top flange 3 is made of steel plate, and its material matches the steel pipe of the cylindrical pile body 1. It is fixedly connected to the upper end of the cylindrical pile body 1 by full welding. Multiple bolt holes are evenly arranged on the pile top flange 3, preferably four. The specifications of the bolt holes match the connecting bolts of the tie rod 4. Their functions are twofold: first, to transfer the tension of the bracket to the cylindrical pile body 1 through the fixed connection of the bolts to the tie rod 4 of the flexible photovoltaic bracket; second, to serve as a stress point for torque application during rotary pile driving, facilitating the fixing of the pile body and the transmission of torque by the pile foundation rotary driving device.

[0046] The construction process of the inclined anchor pile foundation of the present invention includes: construction preparation, pile driver positioning and tilt adjustment, pile alignment, rotary pile driving, pile position correction and fixing, and pile foundation quality testing. The specific methods are as follows: 1. Construction preparation: Technical preparation: Familiarize yourself with the design drawings, clarify the specifications of the pile body (diameter and length of the steel pipe, diameter of the anchor plate, etc.), the depth of penetration into the soil, the pile position deviation (less than or equal to 20mm), and other parameters, prepare a special construction plan and complete the approval and technical briefing; Site preparation: Clear debris from the construction site, level and compact the working surface to ensure the passage and working space for the pile driver. Temporary working platforms can be built in complex terrain. Surveying and setting out: Use instruments such as total station and level to survey and set out the stake positions, drive in the positioning stakes and make clear marks; Material and equipment preparation: Inspect the pile components that arrive on site (pile tip, anchor plate, pile body steel pipe, and pile top flange must be prefabricated and welded in advance), check the material certificate and weld quality, and strictly prohibit the use of components that are deformed or severely corroded; prepare special spiral pile drivers (including power heads and torque control systems), cranes, pile caps and other equipment, debug the equipment to ensure normal operation, and focus on verifying the accuracy of the torque control system.

[0047] 2. Positioning and tilting of the pile driver: Move the auger pile driver to the designated pile position and adjust the position of the pile driver so that the tilt angle of the drill rod centerline is consistent with the design tilt angle of the pile foundation.

[0048] 3. Pile alignment: Use a crane to lift the precast inclined anchor pile foundation and slowly lower it to the bottom of the pile driver drill rod. Align the top flange of the pile with the drill rod interface and fix it firmly with clamps. Readjust the position of the pile body so that the pile tip is accurately aligned with the pile position mark.

[0049] 4. Spinning pile driving: Start the pile driver's power head to drive the pile body to rotate at the set speed, while slowly applying downward pressure. The pile body gradually sinks due to the soil squeezing action of the helical blades at the pile tip. During construction, monitor the torque value and penetration depth in real time. If the torque value suddenly increases or the penetration depth is abnormal, stop the machine to check for obstacles. Forced spinning is strictly prohibited. When the top flange of the pile descends to the design elevation, stop the pile driving and keep the drill rod still for 1-2 minutes to prevent the pile body from rebounding.

[0050] 5. Pile Position Correction and Fixing: After stopping the machine, use a level and total station to re-measure the inclination and top elevation of the pile position. If the deviation exceeds the specification requirements, correct it by finely adjusting the drill rod angle of the pile driver. After correction, backfill a small amount of crushed stone or plain soil around the pile and compact it to temporarily fix the pile body and prevent subsequent construction collisions from causing displacement.

[0051] 6. Pile Foundation Quality Inspection: Visual Inspection: Observe whether the pile body has defects such as deformation and weld cracks, and focus on checking the weld quality between the pile top flange and the pile body steel pipe; Bearing Capacity Test: According to the design requirements, sample the pile body for static pull-out load test to ensure that the ultimate pull-out bearing capacity of a single pile meets the design value; Pile Position Deviation Re-inspection: Randomly check the plane position and verticality of the pile position, and the pass rate must reach 100%; Only after the inspection is qualified can it be handed over to the subsequent diagonal tie rod installation process.

[0052] The transmission path of the ultimate tensile bearing capacity of the inclined anchor pile foundation of the present invention is as follows: tension of the inclined tie rod, flange at the top of the pile, steel pipe of the pile body, anchor plate, self-weight of the cylindrical soil on the anchor plate plus friction of the soil failure surface, and foundation.

[0053] This invention relates to a cable-stayed anchor pile foundation, which breaks away from the traditional model relying on the friction between the pile and the soil for bearing capacity. By installing an anchor plate at the end of the cylindrical pile, the self-weight of the cylindrical soil on the anchor plate and the friction of the soil failure surface jointly provide the ultimate pull-out bearing capacity, achieving a synergy between small pile diameter and high bearing capacity. An integrated structural design is adopted, with the pile tip, anchor plate, pile steel pipe, and pile top flange using a prefabricated welded integrated structure. This ensures structural integrity and stress stability while simplifying on-site construction processes and improving construction efficiency. The multi-functional design of the pile top flange, with multiple bolt holes, simultaneously achieves the dual functions of fixing the cable-stayed rod and applying construction torque, optimizing the structural layout and reducing component processing costs. A construction process adaptable to complex terrain is provided, employing a rotary pile driving method that eliminates the need for mud wall protection or heavy hammering equipment, resulting in low construction noise and vibration, and lower requirements for site flatness, making it suitable for photovoltaic projects in complex terrains such as mountainous areas.

[0054] The inclined anchor pile foundation of this invention forms a dual bearing mode of "soil self-weight + failure surface friction" through the anchor plate. Even with a 30% to 50% reduction in the diameter of the cylindrical pile's steel pipe, the ultimate tensile bearing capacity of a single pile is still increased by more than 20%, significantly reducing material usage and cost. Furthermore, this invention only sets helical blades at the pile tip for pile driving, with the anchor plate solely bearing the tensile force. The structural division is clear, processing is simple, and the integrated welded structure ensures the stability of force transmission, reducing the risk of failure. Using prefabricated integrated piles for direct rotary pile driving eliminates the need for additional processes, shortening the construction cycle by more than 40%. Simultaneously, rotary pile driving produces less noise and vibration, eliminates mud pollution, and has lower requirements for site flatness, making it suitable for complex terrains such as mountains and hills, where existing technologies face significant construction difficulties. Multiple bolt holes on the pile top flange simultaneously achieve the functions of fixing the inclined tie rod and applying construction torque, eliminating the need for additional torque-bearing components and simplifying the structural layout. The pile components of this invention are prefabricated and welded in the factory, making it easy to control the quality of the welds. Only the pile driving and testing procedures need to be completed on site, which reduces the quality fluctuations during on-site construction.

Claims

1. A method for determining parameters of a cable-stayed anchor pile foundation, characterized in that, include: Obtain the preset anchor plate diameter and preset pile tip penetration depth of the inclined anchor pile foundation, as well as the pile foundation inclination angle and other foundation structure parameters of the inclined anchor pile foundation; Based on the preset anchor plate diameter, preset pile tip depth, pile foundation inclination angle and other foundation structure parameters, the pull-out ultimate bearing capacity of the inclined anchor pile foundation under the preset anchor plate diameter and preset pile tip depth is obtained. Obtain the preset pull-out force acting on the inclined anchor pile foundation; Based on the relationship between the preset pull-out force and the ultimate tensile bearing capacity, the preset anchor plate diameter and preset pile tip penetration depth are determined to meet compliance requirements, thereby obtaining the target parameters of the inclined anchor pile foundation; the target parameters include the anchor plate diameter and the pile tip penetration depth.

2. The method for determining parameters of a cable-stayed anchor pile foundation according to claim 1, characterized in that, Based on the preset anchor plate diameter, preset pile tip penetration depth, pile foundation inclination angle, and other foundation structure parameters, the ultimate pull-out bearing capacity of the inclined anchor pile foundation under the preset anchor plate diameter and preset pile tip penetration depth conditions is obtained, including: Based on the preset anchor plate diameter, preset pile tip penetration depth, pile foundation inclination angle and other foundation structure parameters, the soil self-weight above the failure surface of the cylindrical pile body, the soil self-weight between the failure surfaces of the cylindrical pile body and the cohesion on the failure surface of the soil are obtained. The frictional force on the soil failure surface is obtained based on the self-weight of the soil above the failure surface of the cylindrical pile and the self-weight of the soil between the failure surface of the cylindrical pile. Based on the cohesion, friction, and the soil self-weight between the failure surfaces of the cylindrical pile body and the soil, the ultimate pull-out bearing capacity of the inclined anchor pile foundation under the conditions of the preset anchor plate diameter and the preset pile tip insertion depth is obtained.

3. The method for determining parameters of a cable-stayed anchor pile foundation according to claim 2, characterized in that, The frictional force on the soil failure surface is obtained based on the self-weight of the soil above the failure surface of the cylindrical pile and the self-weight of the soil between the failure surfaces of the cylindrical pile and the failure surface, including: The normal component of the soil weight is obtained based on the soil weight above the failure surface of the cylindrical pile and the soil weight between the failure surface of the cylindrical pile. Obtain the internal friction angle of the soil; The frictional force on the soil failure surface is obtained based on the internal friction angle and the normal component.

4. The method for determining parameters of a cable-stayed anchor pile foundation according to claim 2, characterized in that, Based on the cohesion, friction, and the self-weight of the soil between the failure surfaces of the cylindrical pile body and the soil, the ultimate pull-out bearing capacity of the inclined anchor pile foundation under the conditions of the preset anchor plate diameter and the preset pile tip insertion depth is obtained, including: Based on the cohesion, friction, and the self-weight of the soil between the failure surfaces of the cylindrical pile and the soil, the formula is used to... The ultimate pull-out bearing capacity of the inclined anchor pile foundation under the conditions of the preset anchor plate diameter and the preset pile tip insertion depth is obtained; wherein, For the ultimate tensile strength, The self-weight of the soil between the failure surfaces of the cylindrical pile body and the soil body. For the inclination angle of the pile foundation, For friction, It represents cohesive force.

5. The method for determining parameters of a cable-stayed anchor pile foundation according to claim 1, characterized in that, Based on the relationship between the preset pull-out force and the ultimate tensile bearing capacity, the preset anchor plate diameter and preset pile tip penetration depth are assessed for compliance, resulting in the target parameters for the inclined anchor pile foundation, including: The safety factor is obtained based on the relationship between the preset pull-out force and the ultimate pull-out bearing capacity. When the safety factor is greater than or equal to the preset threshold, the compliance determination of the preset anchor plate diameter and the preset pile end penetration depth is passed, and the target parameters are obtained based on the preset anchor plate diameter and the preset pile end penetration depth. When the safety factor is less than a preset threshold, the compliance determination of the preset anchor plate diameter and the preset pile tip penetration depth is determined to be unsuccessful. The values ​​of the preset anchor plate diameter and the preset pile tip penetration depth are increased. The pull-out ultimate bearing capacity is re-determined based on the increased anchor plate diameter and pile tip penetration depth, and a compliance determination is made. When the compliance determination is passed, the target parameters are obtained.

6. A type of inclined anchor pile foundation, characterized in that, include: Cylindrical pile body (1); The pile tip (2) is welded to the first end of the cylindrical pile body (1); A pile top flange (3) is welded to the second end of the cylindrical pile body (1), and a plurality of bolt holes (31) are evenly provided on the pile top flange (3). The tie rod (4) is bolted to the pile top flange (3) through the plurality of bolt holes (31). An anchor plate (5) is disposed on the side of the cylindrical pile body (1) near the first end. The anchor plate (5) is spirally wrapped around the outer surface of the cylindrical pile body (1) and welded to the cylindrical pile body (1). The parameters of the inclined anchor pile foundation are determined by the method described in any one of claims 1 to 5.

7. The inclined anchor pile foundation according to claim 6, characterized in that, The pile tip (2) is conical, and a spiral blade is welded to the outer surface of the pile tip (2).

8. The inclined anchor pile foundation according to claim 6, characterized in that, During the construction of the inclined anchor pile foundation, the plurality of bolt holes (31) are fixedly connected to the pile foundation spinning device.

9. The inclined anchor pile foundation according to claim 6, characterized in that, The anchor plate (5) has a circular ring structure, and the diameter of the outer ring of the anchor plate (5) is larger than the diameter of the cylindrical pile body (1).

10. The inclined anchor pile foundation according to claim 6, characterized in that, The height between the upper and lower bottom surfaces of the cylindrical pile body (1) is greater than the diameter of the circular cross-section of the cylindrical pile body (1).

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