An expandable transmission tower assembled foundation and assembly method thereof

Abstract

The present invention discloses an expandable transmission tower assembled foundation and an assembly method thereof, which relates to the technical field of transmission line foundations, including: a foundation bottom plate, a step base and a column; a step groove and a column groove are provided on the foundation bottom plate; the step base includes a step bottom plate placed in the step groove and a step top plate provided at the bottom end of the column, the step bottom plate and the step top plate are both provided with holes for passing the column, and the foundation bottom plate, the step bottom plate and the step top plate are connected by bolts; a corrugated pipe is provided at the bottom of the column, the column embedded steel bars are provided in the corrugated pipe, the bottom plate embedded steel bars are provided in the column groove, one end of the bottom plate embedded steel bars extends out of the column groove and extends into the corrugated pipe, and is cast with the column embedded steel bars. A bolt connection form capable of reducing the influence of vibration is provided, the reliability and stability of the bolt connection in complex terrain and vibration environment is improved, and the foundation of the transmission tower is suitable for the construction of the foundation under complex terrain and different load conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of power transmission line foundations, and in particular to an expandable power transmission tower assembled foundation and an assembly method thereof. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] In the field of transmission tower foundation design and construction, although the traditional cast-in-place foundation has certain advantages in stability, when facing complex terrain such as mountainous areas and swamps, the traditional construction method may lead to low construction efficiency, significantly increase the construction difficulty and cost, and have a greater impact on the environment. The prefabricated foundation is increasingly widely used in the construction of transmission lines because of its fast construction and small impact on the environment. On the premise of meeting the foundation strength requirements, it speeds up the progress of foundation engineering. However, for areas with diverse landforms and complex terrain, most line towers are usually located in sparsely populated areas such as mountains and wilderness. There are many similar tower types in many lines, but the foundation form is different due to the different soil and tower types. Therefore, the construction environment and construction characteristics have certain particularities, and construction equipment, material transportation and foundation excavation are very difficult. Therefore, it is urgent to propose a foundation form that can adapt to complex and changeable terrain conditions, has low requirements for transportation conditions, and is convenient for on-site installation operations.

[0004] The existing prefabricated foundation connection technology mainly adopts bolt connection, welding and prestressed connection. Bolt connection is widely used because of its simple construction and convenient disassembly, but in the environment of long-term dynamic load or vibration, the bolts may become loose or fatigued, affecting the reliability and stability of the connection, thereby affecting the structural safety of the transmission tower foundation.

[0005] There are currently a variety of anti-loosening measures to solve this problem, such as thread lockers and locking washers, to increase the friction between the bolts and the connected parts or to keep the bolts in a tight state. However, the effectiveness of these measures is affected by many factors and may increase the complexity and cost of construction. Summary of the invention

[0006] In order to solve the above problems, the present invention proposes an expandable transmission tower assembled foundation and an assembly method thereof, wherein the connection between the foundation bottom plate, the step bottom plate and the step top plate is fixed by bolt connection, and the connection between the column and the foundation bottom plate is connected by overlapping the steel bars with slurry poured in a corrugated pipe, providing a bolt connection form that can reduce the impact of vibration, and improving the construction efficiency, reliability and stability of the bolt connection in complex terrain and vibration environment. The invention is suitable for the construction of transmission tower foundations in complex terrain and under different load conditions, ensuring the long-term safe operation of the transmission tower foundation, and solving the problems of inconvenient transportation in complex terrain areas, difficult access for large equipment, and difficult construction.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides an expandable transmission tower assembled foundation, comprising: a foundation bottom plate, a stepped base and a column arranged in sequence from bottom to top;

[0009] The base bottom plate is provided with a step groove for placing a step base and a column groove for placing a column;

[0010] The step base includes a step bottom plate placed in the step groove and a step top plate arranged at the bottom end of the column, the step bottom plate and the step top plate are both provided with holes for passing the column, and the base bottom plate, the step bottom plate and the step top plate are connected by bolts;

[0011] A corrugated pipe is provided at the bottom of the column, and pre-embedded steel bars for the column are provided in the corrugated pipe. Pre-embedded steel bars for the bottom plate are provided in the column groove. One end of the pre-embedded steel bars for the bottom plate extends out of the column groove and into the corrugated pipe, and is cast together with the pre-embedded steel bars for the column.

[0012] As an optional embodiment, the basic floor plate includes an inner plate and at least one outer plate, the inner plate includes an inner convex plate and an inner concave plate, the outer plate includes an outer convex plate and an outer concave plate, the inner plate is composed of the inner convex plate and the inner concave plate spliced ​​end to end, the outer plate is composed of the outer convex plate and the outer concave plate spliced ​​end to end, and the seams of the inner and outer plates are staggered.

[0013] As an optional implementation, both the inner convex plate and the outer convex plate are provided with limit blocks, and both the inner concave plate and the outer concave plate are provided with limit grooves; the inner plate and the outer plate are bolted together via prefabricated connectors.

[0014] As an optional embodiment, bidirectional prestressed holes are provided on the foundation slab, and the prestressed holes are used to pass prestressed steel strands, and the prestressed steel strands are used to apply prestress to the foundation slab to splice the inner convex plate, the inner concave plate, the outer convex plate and the outer concave plate.

[0015] As an optional implementation, the prestressed holes in two directions are staggered.

[0016] As an optional implementation, the stepped bottom plate adopts a conical step, and the slope of the conical step is smaller than the angle between the shear failure surface and the horizontal plane.

[0017] As an optional embodiment, the step bottom plate adopts the same rectangular block as the step top plate.

[0018] As an optional implementation, bolt holes are provided around the holes for passing the columns on the step bottom plate and the step top plate, and vibration-damping sleeves are pre-embedded in the bolt holes.

[0019] As an optional implementation, a threaded sleeve is provided on the periphery of the stepped groove, and a vibration-damping sleeve is provided on the outer side of the threaded sleeve.

[0020] As an optional implementation, a cushion block is provided in the column groove.

[0021] As an optional implementation, a rubber gasket is provided on the bolt.

[0022] As an optional implementation, a protective sleeve is provided on the top of the bolt, an external threaded sleeve is provided in the protective sleeve, and an internal threaded sleeve matching the external threaded sleeve is provided on the stepped top plate.

[0023] In a second aspect, the present invention provides a method for assembling the expandable transmission tower assembled foundation according to the first aspect, comprising:

[0024] The inner convex plate and the inner concave plate are spliced ​​together to form an inner plate, the outer concave plate and the outer convex plate are spliced ​​together on the outer side of the inner plate to form an outer plate, and the inner plate and the outer plate are bolted together by prefabricated connectors to form a base bottom plate;

[0025] Place the step bottom plate in the step groove, place the column through the hole on the step bottom plate into the column groove, and the bottom plate embedded steel bars in the column groove extend out of the column groove and extend into the corrugated pipe;

[0026] Prestressed steel strands are placed in the prestressed holes to apply prestress to the foundation slab, and the inner convex plate, the inner concave plate, the outer convex plate and the outer concave plate are tightened;

[0027] After the prestressing is completed, the foundation bottom plate, the step bottom plate and the step top plate are connected by bolts;

[0028] Grouting is performed into the prestressed holes and corrugated pipes through the grouting holes on the columns, and the embedded steel bars of the bottom plate and the embedded steel bars of the columns are cast and formed. After the grouting material solidifies, the prefabricated connectors are removed to complete the assembly.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention proposes an expandable assembled foundation of a transmission tower that can be used in complex terrain and an assembly method thereof, provides a bolt connection form that can reduce the influence of vibration, and fixes the connection between the foundation bottom plate, the step bottom plate and the step top plate by bolt connection. The assembly process is simple, and wet work on site is reduced, and the impact of construction on the environment is reduced; at the same time, the connection between the column and the foundation bottom plate is connected by a steel bar overlap method in which grout is poured in a corrugated pipe, so as to better transmit the force transmitted from the column downward, optimize the stress distribution, and improve the reliability and stability of the bolt connection in complex terrain and vibration environment; and the pre-embedded steel bars of the bottom plate are formed into a steel bar overlap joint with the pre-embedded steel bars of the column in the corrugated pipe through grouting material, and the corrugated pipe is used as a reserved steel bar overlap hole, which simplifies the construction process, speeds up the construction speed, and reduces the cost.

[0031] The present invention designs the step base into two parts: a step bottom plate and a step top plate. The step bottom plate clamps the spliced ​​foundation bottom plate, and the step top plate is responsible for strengthening the connection between the column and the foundation bottom plate and the step bottom plate, thereby ensuring the integrity of the foundation and ensuring the transmission of the upper force in the foundation. While refining the components, it also solves the problem of poor integrity of the assembled foundation.

[0032] The present invention provides limit blocks on the inner convex plate and the outer convex plate, limit grooves on the inner concave plate and the outer concave plate, and step grooves for placing step bases and column grooves for placing columns on the foundation bottom plate. The above mutually matching concave and convex structures facilitate rapid on-site positioning and splicing, ensure that no misalignment occurs during splicing, and improve construction efficiency. At the same time, the joints of the inner and outer plates are staggered to prevent the generation and expansion of cracks, thereby improving the overall quality of the foundation.

[0033] In the present invention, the inner plate and the outer plate are bolted together by prefabricated connecting parts, and detachable prefabricated connecting parts are used to achieve preliminary positioning to facilitate the placement of prestressed steel strands. The foundation slab is connected by a method of applying prestress by prestressed steel strands. This can not only optimize the stress distribution of the foundation slab and improve the seismic performance of the foundation slab, but also improve the overall stiffness of the spliced ​​foundation slab and enhance its integrity.

[0034] In order to reduce the impact of vibration on the bolts at the connection, vibration-damping sleeves are installed in the step grooves, step base plates and bolt holes of the columns, and pads are installed in the column grooves to reduce the impact of vibration on the bolts and prevent fatigue damage to the bolts. At the same time, rubber gaskets are installed under the bolts to prevent vibration from affecting the bolt preload, avoiding loosening or fatigue damage of the bolts, and improving the safety and reliability of the foundation and the integrity and stability of the connection.

[0035] The present invention provides a stepped bottom enlargement design for the high-load transmission tower foundation, optimizes the module size, facilitates transportation and meets the punching and shearing calculation requirements, enhances the safety of the building structure, and takes into account the limitations of traffic conditions in complex terrain areas. The stepped bottom plate adopts a conical step design, and the slope of the conical step is less than the angle between the shear failure surface and the horizontal plane, which reduces the mass of a single component to ensure the stability and safety of the foundation, thereby improving its transportation convenience under adverse traffic conditions. In this way, not only the mechanical performance requirements for the transmission tower foundation under complex terrain conditions are met, but also the construction efficiency, adaptability and convenience of component transportation of the modular transmission tower foundation are improved, and it is suitable for the construction of transmission tower foundations under complex terrain conditions.

[0036] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0038] Figure 1 The overall structural diagram of the assembled foundation of the expandable transmission tower provided in Example 1 of the present invention;

[0039] Figure 2 An exploded view of an assembled foundation of an expandable transmission tower provided in Example 1 of the present invention;

[0040] Figure 3 for Figure 1 aa section diagram in;

[0041] Figure 4 An enlarged view of the bottom plate provided in Example 1 of the present invention;

[0042] Figure 5 An enlarged view of the stepped bottom plate provided in Example 1 of the present invention;

[0043] Figure 6 An enlarged view of a column provided in Example 1 of the present invention;

[0044] Figure 7 A schematic diagram of a metal bellows provided in Example 1 of the present invention;

[0045] Figure 8 An enlarged view of a bolt provided in Example 1 of the present invention;

[0046] Fig. 9This is the overall structural diagram of the assembled foundation of the expandable transmission tower when the upper load is large;

[0047] Among them: 1. Foundation bottom plate, 11. Inner plate, 111. Step groove, 112. Column groove, 113. Embedded steel bars in the bottom plate, 114. Threaded sleeve, 115. Inner concave plate, 116. Inner convex plate, 12. Outer plate, 121. Outer concave plate, 122. Outer convex plate, 13. Limit block, 14. Limit groove, 15. Prestressed hole, 16. Positioning hole, 17. Prefabricated connecting parts, 18. Connecting bolts, 2. Step bottom plate, 21. Vibration damping sleeve, 3. Column, 31. Step top plate, 32. Metal corrugated pipe, 33. Internally threaded sleeve, 34. Embedded steel bars in the column, 35. Grouting hole, 4. Prestressed steel strand, 5. Protective cap, 51. Externally threaded sleeve, 6. Bolt, 61. Rubber gasket, 62. Smooth screw segment, 63. Threaded screw segment, 7. Cushion block, 8. Bolt hole. DETAILED DESCRIPTION

[0048] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0049] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0050] It should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that the terms "include" and "comprise" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0051] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0052] Example 1

[0053] like Figure 1-Figure 3 As shown, this embodiment provides an expandable transmission tower assembled foundation, which can be applied to complex terrain, including: a foundation bottom plate, a stepped base and columns arranged in sequence from bottom to top;

[0054] The base bottom plate is provided with a step groove for placing a step base and a column groove for placing a column;

[0055] The step base includes a step bottom plate placed in the step groove and a step top plate arranged at the bottom end of the column, the step bottom plate and the step top plate are both provided with holes for passing the column, and the base bottom plate, the step bottom plate and the step top plate are connected by bolts;

[0056] A corrugated pipe is provided at the bottom of the column, and pre-embedded steel bars for the column are provided in the corrugated pipe. Pre-embedded steel bars for the bottom plate are provided in the column groove. One end of the pre-embedded steel bars for the bottom plate extends out of the column groove and into the corrugated pipe, and is cast together with the pre-embedded steel bars for the column.

[0057] In this embodiment, the base bottom plate 1 includes an inner plate 11 and an outer plate 12, the inner plate 11 includes an inner convex plate 116 and an inner concave plate 115, and the outer plate 12 includes an outer convex plate 122 and an outer concave plate 121; the inner convex plate 116 and the outer convex plate 122 are both provided with a limiting block 13, and the inner concave plate 115 and the outer concave plate 121 are both provided with a limiting groove 14, so that during construction, the inner convex plate 116 and the inner concave plate 115, the outer convex plate 122 and the outer concave plate 121 can be accurately aligned.

[0058] As an optional implementation, the inner convex plate 116, the inner concave plate 115, the outer convex plate 122 and the outer concave plate 121 are all provided with positioning holes 16 for use in connection, and the positioning holes 16 are threaded. The positioning holes 16 are used to preliminarily determine the relative positions of the inner plate 11 and the outer plate 12 during construction.

[0059] In this embodiment, if Figure 1 As shown, the joints of the inner plate 11 and the outer plate 12 are staggered to prevent the generation and expansion of cracks and improve the overall quality of the foundation; the prefabricated connecting member 17 is connected to the inner plate 11 and the outer plate 12 by connecting bolts 18, and then a pre-tightening force is applied to the prefabricated connecting member 17 by the connecting bolts 18 to achieve the purpose of clamping the inner plate 11 and the outer plate 12.

[0060] As an optional implementation, the base floor 1 is designed as two layers, inner and outer layers, wherein the inner plate 11 is a rectangular plate, and the outer plate 12 is an L-shaped plate, and precise splicing is ensured by limiting blocks 13 and limiting grooves 14.

[0061] As an optional implementation, the prefabricated connecting member 17 is a high-strength angle steel clamp, which can be recycled during the construction process.

[0062] In this embodiment, if Figure 2 As shown, the foundation slab 1 is provided with bidirectional prestressed holes 15 , and the prestressed steel strands 4 pass through the prestressed holes 15 . The prestressed holes 15 in two directions are staggered.

[0063] The stepped top plate and the column are integrally formed, the foundation bottom plate 1, the stepped bottom plate 2 and the column 3 are all prefabricated in the factory and quickly spliced ​​on site. After the foundation bottom plate 1, the stepped bottom plate 2 and the column 3 are spliced, the post-tensioning method is used to apply prestress to the foundation bottom plate 1 by relying on the prestressed steel strands 4. On the one hand, the prestressed steel strands 4 bear the tensile force, and on the other hand, the inner convex plate 116, the inner concave plate 115, the outer convex plate 122 and the outer concave plate 121 are tightened. After the prestress is applied, grouting is performed. Through the prestressed steel strands 4, the overall stiffness and bearing capacity of the foundation bottom plate 1 are strengthened to ensure the strength and integrity of the connection.

[0064] In this embodiment, if Figure 4 As shown, the base plate 1 is provided with a column groove 112 and a step groove 111, the step plate 2 is placed in the step groove 111, and the column 3 is placed in the column groove 112, so as to ensure the accuracy of splicing the base plate 1, the step plate 2 and the column 3 and the convenience of construction.

[0065] The column groove 112 is provided with a bottom plate embedded steel bar 113, which can be an L-shaped steel bar, one end of which is embedded in the foundation bottom plate 1 and the other end extends out of the column groove 112 plate surface, and the end extending out of the column groove 112 plate surface is poured with on-site grouting material in the metal corrugated pipe 32 at the bottom of the column 3 together with the column embedded steel bar 34.

[0066] This embodiment designs matching concave-convex structures such as limit blocks, limit grooves, column grooves and step grooves, which are convenient for rapid positioning and splicing on site, ensure that there is no misalignment during splicing, facilitate construction, and improve construction efficiency.

[0067] In this embodiment, detachable prefabricated connecting parts are used to achieve preliminary positioning to facilitate the placement of prestressed steel strands, and the foundation slab is connected by applying prestress using prestressed steel strands. This can not only optimize the stress distribution of the foundation slab and improve the seismic performance of the foundation slab, but also improve the overall stiffness of the spliced ​​foundation slab and enhance its integrity.

[0068] In this embodiment, if Figure 5 As shown, the step base plate 2 has a hole in the middle for passing the column 3, and bolt holes 8 are provided in a circle around the hole in the middle of the step base plate 2, and vibration-damping sleeves 21 are embedded in the bolt holes 8; at the same time, a circle of threaded sleeves 114 are embedded in the outer periphery of the step groove 111 of the base base plate 1, and a vibration-damping sleeve 21 is provided on the outer side of the threaded sleeve 114, which is used to enhance the integrity and stability of the foundation connection when connecting the step base plate 2 and the base base plate 1.

[0069] In this embodiment, if Figure 6 As shown, a stepped top plate 31 is provided on the column 3 , a bolt hole 8 is opened on the stepped top plate 31 , and a vibration-damping sleeve 21 is pre-buried in the bolt hole 8 .

[0070] like Figure 3 As shown, the side wall of the column 3 is provided with a grouting hole 35. Figure 7 As shown, the bottom of the column 3 is provided with a pre-buried metal corrugated pipe 32 and a column pre-buried steel bar 34 embedded in the metal corrugated pipe 32. One end of the bottom plate pre-buried steel bar 113 extending out of the column groove 112 plate surface is poured with on-site grouting material in the metal corrugated pipe 32 at the bottom of the column 3 together with the column pre-buried steel bar 34 through the grouting hole 35.

[0071] Specifically, the base plate embedded steel bars 113 are grouting-filled in the metal corrugated tube 32 to form a steel bar lap joint with the column embedded steel bars 34, and the metal corrugated tube 32 is used as a reserved steel bar lap hole, which simplifies the construction process, increases the construction speed and reduces the cost.

[0072] In this embodiment, the connection between the column and the foundation slab is made by overlapping steel bars with slurry poured in a metal corrugated pipe. On the one hand, the design is not convenient for bolt connection, and on the other hand, the overlapped steel bars are used to better transmit the force from the column downward, thereby optimizing the stress distribution.

[0073] In this embodiment, the step is designed to be composed of two parts, a step bottom plate 2 and a step top plate 31. The step bottom plate 2 clamps the spliced ​​base bottom plate 1, and the step top plate 31 is responsible for strengthening the connection between the column 3 and the base bottom plate 1 and the step bottom plate 2, thereby ensuring the integrity of the foundation and ensuring the transmission of the upper force in the foundation. While refining the components, it also solves the problem of poor integrity of the prefabricated foundation.

[0074] This embodiment optimizes the modular design of components for areas with complex terrain, adopts a more detailed module design, improves transportation efficiency, and makes packaging and handling easier, thereby reducing logistics costs. At the same time, the detailed module design has higher adaptability to the foundation design of complex terrain, can be quickly assembled at the construction site, and shortens the construction period.

[0075] In this embodiment, after the base bottom plate 1, the step bottom plate 2 and the column 3 are spliced ​​together, the connection between the base bottom plate 1, the step bottom plate 2 and the step top plate 31 is fixed by bolts 6. The base bottom plate, the step bottom plate and the step top plate are fixed by bolt connection. The assembly process is simple, which can reduce on-site wet operations and help reduce the impact of construction on the environment.

[0076] like Figure 8 As shown, the bottom of the bolt 6 is provided with a threaded screw section 63, the upper and middle part is a smooth screw section 62, and a rubber gasket 61 is arranged under the nut when connected.

[0077] In this embodiment, if Figure 8As shown, a protective sleeve 5 is provided on the top of the bolt 6, an external threaded sleeve 51 is provided in the protective sleeve 5, and an internal threaded sleeve 33 matching the external threaded sleeve 51 is provided on the stepped top plate 31. When connected, the protective sleeve 5 is tightened by the external threaded sleeve 51 and the internal threaded sleeve 33.

[0078] As an optional implementation, the protective cover 5 is cast by modified butyl rubber and coated with anti-corrosion paint on the outside to prevent the underground environment from corroding the bolts and improve durability.

[0079] In this embodiment, in order to reduce the influence of vibration on the bolts at the connection, a vibration-damping sleeve 2 is arranged in the step groove 111, the step base plate 2 and the bolt hole 8 of the column 3, and a cushion block 7 is arranged in the column groove 112 to reduce the influence of vibration on the bolts and prevent the bolts from being damaged by fatigue. At the same time, a rubber gasket 61 is arranged under the bolt 6 to prevent vibration from affecting the preload force of the bolt, avoid the problem of loosening or fatigue damage of the bolt, and improve the safety and reliability of the foundation.

[0080] As an optional implementation, the pad 7, rubber gasket 61 and vibration-damping sleeve 21 are all made of multiple layers of rubber sheets and stiffening steel plates bonded, pressed and vulcanized, which improves the reliability of the bolt connection and ensures the stability and reliability of the foundation in complex terrain.

[0081] For the transmission tower foundation with large upper load, the net reaction force of the foundation soil and the bottom area of ​​the foundation are increased, and the foundation height is correspondingly increased. Therefore, on this basis, in order to ensure that the foundation can meet the shear calculation, the component design and module size should be optimized as much as possible to facilitate transportation.

[0082] Therefore, in this embodiment, by increasing the area of ​​the stepped bottom plate or increasing the outer dimensions of the foundation bottom plate, such as adding another circle of foundation bottom plate on the outside, the bottom area of ​​the foundation is increased, the module size is optimized, and it is ensured that the foundation meets the shear verification requirements.

[0083] Specifically, Fig. 9 As shown, in order to ensure that the foundation slab 1 can meet the punching shear verification conditions when the upper load is large, a larger component size is used, and the stepped slab 2 is enlarged;

[0084] At the same time, taking into account the limitations of traffic conditions in complex terrain areas, innovative improvements are made to the step base plate 2, adopting a conical step design. The slope of the conical step is smaller than the angle between the shear failure surface and the horizontal plane, thereby reducing the mass of a single component to ensure the stability and safety of the foundation, thereby improving its transportation convenience under adverse traffic conditions.

[0085] Through the above design improvements, this embodiment not only meets the mechanical performance requirements of the transmission tower foundation under complex terrain conditions, but also improves the construction efficiency, adaptability and convenience of component transportation of the modular transmission tower foundation, and is suitable for the construction of transmission tower foundations under complex terrain conditions.

[0086] Example 2

[0087] The present embodiment provides an assembly method for the assembled foundation of the expandable transmission tower described in Embodiment 1, wherein the foundation base plate 1, the step base plate 2 and the columns 3 are all prefabricated in a factory, and the foundation base plate 1 is prestressed on site by prestressed steel strands 4, and the foundation base plate 1, the step base plate 2 and the columns 3 are fixedly connected by bolts 6 to form an integral structure.

[0088] Specifically:

[0089] The inner convex plate 116 and the inner concave plate 115 are spliced ​​together to form the inner plate 11, and the outer concave plate 121 and the outer convex plate 122 are spliced ​​together on the outer side of the inner plate 11 to form the outer plate 12;

[0090] The prefabricated connecting member 17 is fixedly connected to the inner plate 11 and the outer plate 12 by connecting bolts 18 to form the base bottom plate 1;

[0091] Place the pad 7 in the column groove 112, place the step bottom plate 2 in the step groove 111, insert the column 3 through the opening on the step bottom plate 2 into the column groove 112, and the bottom plate embedded steel bars 113 in the column groove 112 extend out of the column groove 112 and extend into the metal corrugated pipe 32;

[0092] A prestressed steel strand 4 is placed in the prestressed hole 15, and a post-tensioning method is used to apply prestress to the foundation bottom plate 1 by means of the prestressed steel strand 4. The prestressed steel strand 4 bears the tensile force on the one hand, and on the other hand tightens the inner convex plate 116, the inner concave plate 115, the outer convex plate 122 and the outer concave plate 121;

[0093] After the prestress is applied, the foundation bottom plate 1, the step bottom plate 2 and the step top plate 31 are fixedly connected by bolts 6, and protective caps 5 are installed to prevent the bolts 6 from being corroded;

[0094] Finally, grouting is performed into the prestressed hole 15 and the metal bellows 32 through the grouting hole 35. After the grouting material is solidified, the prefabricated connecting parts are removed to complete the construction.

[0095] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. An expandable transmission tower assembled foundation, characterized in that: include: The foundation slab, stepped base and columns are arranged in sequence from bottom to top; The base bottom plate is provided with a step groove for placing a step base and a column groove for placing a column; The step base includes a step bottom plate placed in the step groove and a step top plate arranged at the bottom end of the column, the step bottom plate and the step top plate are both provided with holes for passing the column, and the base bottom plate, the step bottom plate and the step top plate are connected by bolts; The bottom of the column is provided with a corrugated pipe, the column embedded steel bars are arranged in the corrugated pipe, the bottom plate embedded steel bars are arranged in the column groove, one end of the bottom plate embedded steel bars extends out of the column groove and extends into the corrugated pipe, and is cast together with the column embedded steel bars; The base floor comprises an inner plate and at least one outer plate, the inner plate comprises an inner convex plate and an inner concave plate, the outer plate comprises an outer convex plate and an outer concave plate, the inner plate is formed by splicing the inner convex plate and the inner concave plate end to end in sequence, the outer plate is formed by splicing the outer convex plate and the outer concave plate end to end in sequence, and the splicing seams of the inner plate and the outer plate are staggered; The base plate is designed as two layers, the inner plate is a rectangular plate, and the outer plate is an L-shaped plate, and the limit blocks and limit grooves are used to ensure accurate splicing; The side wall of the column is provided with grouting holes, the bottom of the column is provided with a pre-buried metal corrugated pipe and pre-buried steel bars for the column embedded in the metal corrugated pipe, one end of the bottom plate pre-buried steel bars extending out of the column groove plate surface is poured with on-site grouting material through the grouting holes in the metal corrugated pipe at the bottom of the column together with the pre-buried steel bars for the column.

2. The expandable transmission tower assembled foundation according to claim 1, characterized in that: The inner convex plate and the outer convex plate are both provided with limit blocks, and the inner concave plate and the outer concave plate are both provided with limit grooves; the inner plate and the outer plate are bolted together via prefabricated connectors.

3. The expandable transmission tower assembled foundation according to claim 1, characterized in that: The foundation slab is provided with bidirectional prestressed holes, the prestressed holes are used to pass prestressed steel strands, and the prestressed steel strands are used to apply prestress to the foundation slab to splice the inner convex plate, the inner concave plate, the outer convex plate and the outer concave plate.

4. The expandable transmission tower assembled foundation according to claim 3, characterized in that: The prestressed holes in two directions are staggered.

5. The expandable transmission tower assembled foundation according to claim 1, characterized in that: The step bottom plate adopts a conical step, and the slope of the conical step is smaller than the angle between the shear failure surface and the horizontal plane.

6. The expandable transmission tower assembled foundation according to claim 1, characterized in that: The step bottom plate adopts the same rectangular block as the step top plate.

7. The expandable transmission tower assembled foundation according to claim 1, characterized in that: Bolt holes are arranged around the holes for passing the columns on the step bottom plate and the step top plate, and vibration-damping sleeves are pre-embedded in the bolt holes; A threaded sleeve is disposed on the periphery of the stepped groove, and a vibration-damping sleeve is disposed on the outer side of the threaded sleeve; A cushion block is provided in the column groove; A rubber gasket is arranged on the bolt.

8. The expandable transmission tower assembled foundation according to claim 1, characterized in that: A protective sleeve is arranged on the top of the bolt, an external thread sleeve is arranged in the protective sleeve, and an internal thread sleeve matching the external thread sleeve is arranged on the stepped top plate.

9. A method for assembling an expandable transmission tower assembled foundation according to any one of claims 1 to 8, characterized in that: include: The inner convex plate and the inner concave plate are spliced ​​together to form an inner plate, the outer concave plate and the outer convex plate are spliced ​​together on the outer side of the inner plate to form an outer plate, and the inner plate and the outer plate are bolted together by prefabricated connectors to form a base bottom plate; Place the step bottom plate in the step groove, place the column through the hole on the step bottom plate into the column groove, and the bottom plate embedded steel bars in the column groove extend out of the column groove and extend into the corrugated pipe; Prestressed steel strands are placed in the prestressed holes to apply prestress to the foundation slab, and the inner convex plate, the inner concave plate, the outer convex plate and the outer concave plate are tightened; After the prestressing is completed, the foundation bottom plate, the step bottom plate and the step top plate are connected by bolts; Grouting is performed into the prestressed holes and corrugated pipes through the grouting holes on the columns, and the embedded steel bars of the bottom plate and the embedded steel bars of the columns are cast and formed. After the grouting material solidifies, the prefabricated connectors are removed to complete the assembly.

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