Multi-point gravity expansion type foundation for truss type tower and construction method of multi-point gravity expansion type foundation

Abstract

The invention provides a multi-point gravity expansion type foundation for a truss type tower, which comprises a plurality of foundation units and is characterized in that each foundation unit comprises an upper cylindrical bearing platform, and the bottom of each upper cylindrical bearing platform is a lower circular platform bearing platform; the top of one foundation unit is connected with one side stand column of the truss type tower, so that the multi-point array type gravity expansion type foundation structure is formed. The foundation structure is mature in construction technology, safe and reliable in strength, capable of well supporting a truss type tower structure and capable of serving as a foundation scheme of the truss type tower.

Description

Technical Field

[0001] The invention relates to the technical field of foundation construction of an onshore wind turbine generator set, and in particular to a multi-point gravity expansion foundation for a truss tower and a construction method thereof. Background Art

[0002] Wind power projects are clean energy projects that use wind power to generate electricity. Traditional wind turbines usually use steel or reinforced concrete towers. Conventional tower structures usually use gravity expansion foundations, which are stable and reliable, have mature construction processes, and are cost-controlled. Truss wind turbine towers that have emerged in recent years are gradually being applied to various wind farms due to their small amount of steel, simple manufacturing, and convenient transportation. Since the truss tower is in the application exploration stage, there is currently no mainstream solution or mature, process-based construction technology for connecting the lower foundation of the truss tower.

[0003] 1. Comparative document CN206376981U discloses a truss tower and a wind turbine generator set including the truss tower. The truss tower includes: a tower base, the tower base includes at least three reinforced concrete columns; a tower body, the tower body is a truss structure, and is arranged on the tower base. The truss tower according to the utility model has a small footprint and high strength. The reinforced concrete column foundation is stable in form and reliable in strength, but the amount of concrete used is large and the construction cost is high.

[0004] 2. Comparative document CN201720407343 discloses a semi-truss tower, which uses a single pile foundation to connect the truss tower. The single pile foundation is widely used and has low construction cost. However, the diameter of the single pile foundation used to adapt to the truss tower is relatively small, and there is a risk of insufficient bearing capacity.

[0005] Therefore, it is urgent to invent a multi-point gravity expansion foundation for a truss tower and a construction method thereof to solve the problem. Summary of the invention

[0006] The object of the present invention is to overcome the above-mentioned shortcomings and provide a multi-point gravity expansion foundation for a truss tower and a construction method thereof to solve the problems raised in the background technology.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: a multi-point gravity expansion foundation for a truss tower, including multiple foundation units, the foundation unit includes an upper cylindrical base, the bottom of the upper cylindrical base is a lower circular base, and the top of a foundation unit is connected to a side column of the truss tower to form a multi-point array gravity expansion foundation structure.

[0008] Preferably, the foundation unit is a reinforced concrete structure, and an anchor cage is pre-embedded in the foundation unit.

[0009] Preferably, the anchor cage is a prefabricated structure, the upper portion of the anchor cage is a cylindrical structure, and the lower portion of the anchor cage is a support frame structure.

[0010] Preferably, the cylindrical structure includes a plurality of anchor rods arranged equidistantly in a ring shape, the upper ends of the anchor rods are reserved to the top surface of the upper cylindrical pedestal, and the anchor rods are arranged vertically.

[0011] Preferably, the anchor rod is connected and fixed to the side column of the truss tower by high-strength bolts.

[0012] Preferably, the number and positions of the basic units are set according to the number and positions of the side columns of the truss tower.

[0013] Preferably, the upper cylindrical pedestal is larger than the outer extension surface of the side column to provide sufficient support area, and the diameter of the lower cylindrical pedestal is 3-4 times the diameter of the upper cylindrical pedestal to ensure the stability of the foundation.

[0014] In addition, the present invention also discloses a construction method for a multi-point gravity expansion foundation of a truss tower, comprising the following steps: S1. Positioning and measuring and setting out: according to the truss structure parameters, the preset basic units are positioned and measured and set out. The number of basic unit positioning is consistent with the number of side columns; S2. Excavation of foundation pit, the excavation depth is 0.5-1 times the diameter of the upper cylindrical pedestal, to ensure that the foundation depth is sufficient, and the excavation working surface of the foundation pit needs to match the number of truss side columns; S3. Pouring of cushion layer, the cushion layer is cast-in-place concrete, the pouring area is slightly smaller than the excavation area of ​​the foundation pit, and the thickness is about 3-5cm; S4. Anchor cage installation: place the prefabricated anchor cage at the predetermined location and lay the bottom layer of annular reinforcement and bottom layer of radial reinforcement; S5. Lay the circumferential and radial reinforcements around the anchor cage. The top reinforcement is laid along the circumference of the anchor cage, and vertical support reinforcement is laid between the top reinforcement and the bottom reinforcement; S6. Formwork support and pouring: annular formwork support is set on the side walls of the upper cylindrical pedestal and the lower truncated pedestal, and concrete is poured into the structure inside the formwork to ensure that the concrete is fully filled and vibrated to be dense; S7. Curing and backfilling: After the concrete is cured, remove the formwork, backfill the foundation pit, complete the extended foundation construction, and install the side columns on the top plane of the upper cylindrical pedestal.

[0015] Furthermore, the specific operation of S4 is to open two circles of screw holes on the upper and lower steel plates of the cylindrical structure along the anchor rod setting points, with anchor rods fixed in the screw holes. The anchor rods are exposed for a certain length for connection and fixation with the inclined columns of the first-floor truss, and screw holes are opened along the side wall of the lower steel plate for inserting and fixing the top-level steel bars.

[0016] Furthermore, in step S5, the annular and radial steel bars, the vertical support steel bars and the top and bottom steel bars can be fixed by binding.

[0017] The present invention has the following beneficial effects: 1. The present invention adopts modular design, and the number and position of the multi-point construction foundation units are set according to the number and position of the side columns of the truss tower, which saves the amount of concrete while ensuring safety; 2. In the present invention, the anchor rod and the side column of the truss tower are connected and fixed by high-strength bolts, which is convenient for installation and maintenance and improves the convenience of construction and installation; 3. The present invention adopts an extended foundation compatible with the truss tower, which effectively reduces the center of gravity and load effect of the overall structure, increases the load-bearing area, and ensures the safety and stability of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a side view of the basic unit in the present invention; Figure 2 It is a plan view of the basic unit in the present invention; Figure 3 It is a schematic plan view of the connection between four basic units and the bottom truss in the present invention; Figure 4 It is a side view of the anchor cage structure of the present invention; Figure 5 A side view of the internal reinforcement arrangement of the foundation unit of the present invention; Figure 6 It is a schematic plan view of the arrangement of the annular and radial reinforcement bars in the bottom layer of the foundation unit in the present invention; Figure 7 It is a schematic diagram of the connection relationship between the truss tower and the foundation of the present invention; Figure 8 It is a front view of the multi-point expansion basic connection relationship in the present invention. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: See also Figures 1 to 8 A multi-point gravity expansion foundation for a truss tower includes a plurality of foundation units 1, wherein the foundation unit 1 includes an upper cylindrical base 2, the bottom of the upper cylindrical base 2 is a lower cylindrical base 5, and the top of a foundation unit 1 is connected to a side column 4 of the truss tower to form a multi-point array gravity expansion foundation structure. The truss tower is a steel structure, and the side columns 4 are three or four columns, and the columns are horizontally connected with transverse support rods.

[0020] Preferably, the foundation unit 1 is a reinforced concrete structure, and an anchor cage 3 is pre-embedded in the foundation unit 1. The anchor rod 3.1 portion of the anchor cage 3 above the top surface of the extended foundation is connected to the outer surface of each column of the truss tower through a high-strength nut.

[0021] Preferably, the anchor cage 3 is a prefabricated structure, the upper portion of the anchor cage 3 is a cylindrical structure 3.2, and the lower portion of the anchor cage 3 is a support frame structure 3.3.

[0022] Preferably, the cylindrical structure 3.2 includes a plurality of anchor rods 3.1 arranged equidistantly in a ring shape, the upper ends of the anchor rods 3.1 are reserved to the top surface of the upper cylindrical base 2, and the anchor rods 3.1 are arranged vertically.

[0023] Preferably, the anchor rod 3.1 is connected and fixed to the truss tower side column 4 by high-strength bolts.

[0024] Preferably, the number and positions of the basic units 1 are set according to the number and positions of the side columns 4 of the truss tower.

[0025] Preferably, the upper cylindrical pedestal 2 is larger than the outer extension surface of the side column 4 to provide sufficient supporting area, and the diameter of the lower cylindrical pedestal 5 is 3-4 times the diameter of the upper cylindrical pedestal 2 to ensure the stability of the foundation.

[0026] In addition, the present invention also discloses a construction method for a multi-point gravity expansion foundation of a truss tower, comprising the following steps: S1. Positioning and measuring and setting out: according to the truss structure parameters, the preset basic unit 1 is positioned, measured and set out. The number of positioning of the basic unit 1 is consistent with the number of side columns; S2. Excavation of foundation pit, the excavation depth is 0.5-1 times the diameter of the upper cylindrical cap 2, to ensure that the foundation depth is sufficient, and the excavation working surface of the foundation pit needs to match the number of truss side columns; S3. Pouring of cushion layer, the cushion layer is cast-in-place concrete, the pouring area is slightly smaller than the excavation area of ​​the foundation pit, and the thickness is about 3-5cm; S4. Anchor cage 3 is installed, the prefabricated anchor cage 3 is placed at a predetermined point, and the bottom annular steel bars and the bottom radial steel bars are laid; S5. Laying circumferential and radial reinforcement around the anchor cage 3, the top layer of reinforcement is laid along the circumference of the anchor cage 3, and vertical support reinforcement is laid between the bottom layer of reinforcement; S6. Formwork support and pouring. The upper cylindrical cap 2 and the lower truncated cap 5 are provided with annular formwork support on the side walls. Concrete is poured into the structure inside the formwork to ensure that the concrete is fully filled and vibrated to make it dense; S7. Curing and backfilling. After the concrete is cured, the formwork is removed, the foundation pit is backfilled, the extended foundation construction is completed, and the side columns 4 are installed on the top plane of the upper cylindrical base 2.

[0027] Furthermore, the specific operation of S4 is to open two circles of screw holes on the upper and lower steel plates of the cylindrical structure 3.2 along the setting points of the anchor rod 3.1, and the anchor rod 3.1 is fixed in the screw hole. The anchor rod 3.1 is exposed for a certain length to be connected and fixed with the inclined columns of the first-floor truss, and screw holes are opened along the side wall of the lower steel plate for inserting and fixing the top-level steel bars.

[0028] Furthermore, in step S5, the annular and radial steel bars, the vertical support steel bars and the top and bottom steel bars can be fixed by binding.

[0029] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limiting the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A multi-point gravity expansion foundation for a truss tower, comprising a plurality of foundation units (1), characterized in that: The foundation unit (1) comprises an upper cylindrical support platform (2), the bottom of the upper cylindrical support platform (2) is a lower cylindrical support platform (5), and the top of a foundation unit (1) is connected to a side column (4) of a truss tower to form a multi-point array gravity expansion foundation structure.

2. A multi-point gravity expansion foundation for a truss tower according to claim 1, characterized in that: The foundation unit (1) is a reinforced concrete structure, and an anchor cage (3) is pre-buried in the foundation unit (1).

3. A multi-point gravity expansion foundation for a truss tower according to claim 2, characterized in that: The anchor bolt cage (3) is a prefabricated structure, the upper portion of the anchor bolt cage (3) is a cylindrical structure (3.2), and the lower portion of the anchor bolt cage (3) is a support frame structure (3.3).

4. A multi-point gravity expansion foundation for a truss tower according to claim 3, characterized in that: The cylindrical structure (3.2) comprises a plurality of anchor rods (3.1) arranged equidistantly in a ring shape, the upper ends of the anchor rods (3.1) being reserved for the top surface of the upper cylindrical pedestal (2), and the anchor rods (3.1) being arranged vertically.

5. A multi-point gravity expansion foundation for a truss tower according to claim 4, characterized in that: The anchor rod (3.1) is connected and fixed to the truss-type tower side column (4) by means of high-strength bolts.

6. The multi-point gravity expansion foundation for a truss tower according to claim 1, characterized in that: The number and positions of the basic units (1) are set according to the number and positions of the side columns (4) of the truss-type tower.

7. A construction method for a multi-point gravity expansion foundation for a truss tower according to claim 1, characterized in that: The upper cylindrical support (2) is larger than the outer surface of the side column (4) to provide a sufficient support area. The diameter of the lower cylindrical support (5) is 3-4 times the diameter of the upper cylindrical support (2) to ensure the stability of the foundation.

8. A construction method for a multi-point gravity expansion foundation for a truss tower according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Positioning and measuring and laying out: positioning and measuring and laying out the preset basic unit (1) according to the truss structure parameters; the number of positioning the basic unit (1) is consistent with the number of side columns (4); S2. Excavate the foundation pit. The excavation depth is 0.5-1 times the diameter of the upper cylindrical pedestal (2). Ensure that the foundation depth is sufficient. The excavation working surface of the foundation pit must match the number of truss side columns. S3. Pouring of cushion layer, the cushion layer is cast-in-place concrete, the pouring area is slightly smaller than the excavation area of ​​the foundation pit, and the thickness is about 3-5cm; S4 anchor cage (3) installation, the prefabricated anchor cage (3) is placed at a predetermined point, laying the bottom layer of annular reinforcement and the bottom layer of radial reinforcement; S5. Laying the annular and radial reinforcements around the anchor cage (3), the top layer of reinforcements is laid along the circumference of the anchor cage (3), and vertical support reinforcements are laid between the bottom layer of reinforcements; S6. Formwork support and pouring: an annular formwork support is provided on the side walls of the upper cylindrical pedestal (2) and the lower truncated pedestal (5), and concrete is poured into the structure inside the formwork to ensure that the concrete is fully filled and vibrated to be dense; S7. Curing and backfilling: After the concrete is cured, the formwork is removed, the foundation pit is backfilled, and the extended foundation construction is completed. The side columns (4) are installed on the top plane of the upper cylindrical pedestal (2).

9. A construction method for a multi-point gravity expansion foundation for a truss tower according to claim 8, characterized in that: The specific operation of S4 is to open two circles of screw holes along the anchor rod (3.1) setting points of the upper and lower steel plates of the cylindrical structure (3.2), the anchor rod (3.1) is fixed in the screw holes, and the anchor rod (3.1) is exposed for a certain length to be connected and fixed to the inclined columns of the first-floor truss, and screw holes are opened along the side wall of the lower steel plate for inserting and fixing the top-layer steel bars.

10. A construction method for a multi-point gravity expansion foundation for a truss tower according to claim 8, characterized in that: The annular and radial steel bars, the vertical supporting steel bars and the top and bottom steel bars in S5 can be fixed by binding.

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