A thin-walled large-diameter single pile-barrel composite pile foundation and its installation method

Abstract

The present invention provides a thin-walled large-diameter single pile-barrel composite pile foundation and an installation method thereof, comprising an outer barrel foundation and a thin-walled variable-section single pile foundation located in the middle of the outer barrel foundation, the thin-walled variable-section single pile foundation comprising an upper foundation and a lower foundation, the diameter of the upper foundation is smaller than the lower foundation, a plurality of annular plates are arranged at intervals from top to bottom on the inner side of the upper foundation, a plurality of vertical ribs are evenly arranged between the outer wall of the annular plate and the inner wall of the upper foundation, a plurality of annular reinforcement beams are arranged circumferentially on the outer side of the lower foundation, and Y-shaped reinforcement ribs are arranged between adjacent annular reinforcement beams. The present invention is reasonably designed, and can provide higher bearing capacity and rigidity than traditional single pile foundations, and can be used as a foundation form for larger wind turbine power; in terms of specific structure, the wall thickness of the same foundation is optimized, which not only ensures structural strength but also saves steel, and has good economy; it is connected to the outer barrel foundation by grouting, which can significantly improve its bearing performance.

Description

Technical Field

[0001] The invention relates to a thin-walled large-diameter single pile-barrel composite pile foundation and an installation method thereof. Background Art

[0002] In recent years, my country has vigorously developed renewable clean energy, and offshore wind energy resources have always been the focus of attention. The construction of offshore wind power requires knowledge and technology in multiple disciplines and fields such as wind turbine foundations, towers, and wind turbines. At present, the commonly used offshore wind turbine foundations are single pile foundations and jacket foundations, of which the proportion of single pile foundations exceeds 70%, mainly because of its relatively simple structure, easy production, mature installation technology, and low overall cost, so it has been widely used. At present, the diameter of the general wind turbine foundation is 4-6m, and the pile length depends on the soil conditions.

[0003] However, since offshore wind turbine foundations generally bear large horizontal loads and bending moment loads, it is difficult for general wind turbine foundations with high power to withstand such large loads, especially when their diameter is small. Although increasing the diameter of the foundation can significantly improve the bearing capacity and stiffness of the foundation, the wall thickness needs to be increased to ensure structural strength while increasing the pile diameter, resulting in a significant increase in the amount of steel used, which in turn leads to a significant increase in the foundation manufacturing cost and transportation and installation cost. Therefore, it is necessary to optimize the wall thickness to achieve the purpose of both structural strength and economic savings. At the same time, the barrel foundation and grouting method can be combined to improve the bearing performance of the foundation. Therefore, based on the above engineering background, this patent proposes a thin-walled large-diameter single pile-barrel composite pile foundation. Summary of the invention

[0004] The present invention improves the above-mentioned problem, that is, the technical problem to be solved by the present invention is to provide a thin-walled large-diameter single pile-barrel composite pile foundation and an installation method thereof, which is simple to operate, can meet the structural strength and is economical, and at the same time effectively improves the bearing performance of the single pile foundation.

[0005] The present invention is constructed as follows: it includes an outer barrel foundation and a thin-walled variable-section single pile foundation located in the middle of the outer barrel foundation, wherein the thin-walled variable-section single pile foundation includes an upper foundation portion and a lower foundation portion, wherein the diameter of the upper foundation portion is smaller than that of the lower foundation portion, wherein a plurality of annular plates are arranged at intervals from top to bottom on the inner side of the upper foundation portion, wherein a plurality of vertical ribs are evenly arranged between the outer wall of the annular plate and the inner wall of the upper foundation portion, wherein a plurality of annular reinforcement beams are arranged circumferentially on the outer side of the lower foundation portion, and Y-shaped reinforcement ribs are arranged between adjacent annular reinforcement beams.

[0006] Furthermore, a plurality of grouting holes are provided on the upper surface of the outer barrel foundation, and a grouting sleeve is passed through the grouting holes. The grouting sleeve is T-shaped, so that the upper part of the grouting sleeve is against the upper surface of the outer barrel foundation, and the lower part of the grouting sleeve extends downward to the inside of the outer barrel foundation. A plurality of grouting holes are opened on the lower side of the grouting sleeve for grouting into the inside of the outer barrel foundation and forming a grouting body.

[0007] Furthermore, the outer barrel-shaped foundation includes a barrel skirt and a barrel top plate located above the barrel skirt, and a plurality of reinforcing wing plates are arranged above the barrel top plate and around the center of the barrel top plate.

[0008] Furthermore, a through hole is reserved in the middle of the barrel top plate for the installation of a thin-walled variable-section single pile foundation, and a grouting annular plate is arranged on the outer peripheral side of the through hole. The lower part of the grouting annular plate is welded to the barrel top plate, and the diameter of the grouting annular plate increases from bottom to top, and an annular reinforcing grouting body is cast inside the grouting annular plate.

[0009] Furthermore, the wall thickness of the thin-walled variable-section single pile foundation is not greater than 6 cm.

[0010] Furthermore, the upper part of the foundation is located above the mud surface, and the lower part of the foundation is located below the mud surface. The cross-sectional diameter of the upper part of the foundation decreases from bottom to top and then remains unchanged, and the cross-sectional diameter of the lower part of the foundation is the same.

[0011] Furthermore, the Y-shaped reinforcing rib is composed of two "V"-shaped connecting ribs and a protruding wing plate, the inner ends of the two connecting ribs are connected to the lower part of the foundation, and the outer ends of the two connecting ribs are connected together and connected to the telescopic wing plate.

[0012] Furthermore, a method for installing a thin-walled large-diameter single pile-barrel composite pile foundation comprises the following steps: (1) firstly, the thin-walled variable-section single pile foundation is driven into a specified depth of the soil layer, and the inclination rate and pile quality of the thin-walled variable-section single pile foundation are controlled; (2) after the thin-walled variable-section single pile foundation is installed, the outer barrel foundation is hoisted and installed from the top of the thin-walled variable-section single pile foundation, and the soil is inserted under the barrel skirt of the outer barrel foundation. After the barrel top plate above the outer barrel foundation contacts the soil layer, grouting treatment is performed at the junction of the thin-walled variable-section single pile foundation and the outer barrel foundation to form a ring-shaped reinforced grouting body; (3) if the soil around the thin-walled variable-section single pile foundation needs to be strengthened, a grouting pipe can be lowered. If the soil in a deeper layer needs to be strengthened, the grouting pipe can be installed with the aid of certain vibration equipment; (4) after the grouting pipe is installed, grouting is performed on the grouting pipe to form a grouting body around the grouting pipe, the shallow surface soil of the foundation is strengthened, and the bearing capacity can be further improved.

[0013] Compared with the prior art, the present invention has the following beneficial effects: the present invention has a simple structure and a reasonable design. Compared with the traditional single pile foundation, it can provide higher bearing capacity and rigidity, and can be used as a foundation form for larger wind turbine power; in terms of the specific structure, it is optimized by optimizing the wall thickness of the foundation, which not only ensures the structural strength but also saves steel and has good economy; in addition, it is connected to the outer barrel foundation by grouting, and can be combined with other grouting methods, which can significantly improve its bearing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The overall structure of the embodiment of the present invention is shown in FIG. Figure 1 ;

[0015] Figure 2 The overall structure of the embodiment of the present invention is shown in FIG. Figure 2 ;

[0016] Figure 3 This is a schematic diagram of the structure of the connection between the thin-walled variable-section single pile foundation and the outer barrel foundation according to an embodiment of the present invention;

[0017] Figure 4 This is a top view of the outer barrel foundation of an embodiment of the present invention;

[0018] Figure 5 A top view of an outer barrel foundation with grouting holes according to an embodiment of the present invention;

[0019] Figure 6 It is a cross-sectional view of the bottom part of the foundation of an embodiment of the present invention;

[0020] Figure 7 It is a cross-sectional view of the upper part of the foundation of an embodiment of the present invention;

[0021] Figure 8 for Figure 6 A partial enlarged view of

[0022] Fig. 9 for Figure 1 Partial enlargement diagram B;

[0023] In the figure: 1-thin-wall variable-section single pile foundation, 110-upper part of foundation, 120-lower part of foundation, 2-outer barrel foundation, 3-perforation, 4-vertical ribs, 5-annular plates, 6-Y-shaped reinforcement ribs, 7-annular reinforcement beams, 8-reinforcement beam cross plates, 9-reinforcement beam vertical plates, 10-connecting ribs, 11-extending wing plates, 12-grouting annular plates, 13-reinforced wing plates, 14-annular reinforcement grouting bodies, 15-barrel skirts, 16-barrel top plates, 17-grouting holes, 18-grouting sleeves, 19-circular baffles, 20-grouting bodies. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Example: Figures 1 to 9 As shown, a thin-walled large-diameter single pile-barrel composite pile foundation is provided, including an outer barrel-shaped foundation 2 and a thin-walled variable-section single pile foundation 1 located in the middle of the outer barrel-shaped foundation, wherein the thin-walled variable-section single pile foundation includes a foundation upper portion 110 and a foundation lower portion 120, wherein the diameter of the foundation upper portion is smaller than that of the foundation lower portion, and a plurality of annular plates 5 are arranged at intervals from top to bottom on the inner side of the foundation upper portion to strengthen the strength of the foundation upper portion, and a plurality of vertical ribs 4 are evenly arranged between the outer wall of the annular plate and the inner wall of the foundation upper portion, and a plurality of annular reinforcement beams 7 are arranged circumferentially on the outer side of the foundation lower portion, and Y-shaped reinforcement ribs 6 are arranged between adjacent annular reinforcement beams.

[0026] In order to ensure the structural rigidity of the upper part of the foundation, the above-mentioned vertical ribs can be evenly arranged at 8 numbers, the angle between adjacent vertical ribs is 45°, the vertical ribs are connected from top to bottom and the thickness is slightly lower than the wall thickness of the thin-walled variable-section single pile foundation; the thickness of the annular plate can be the same as the thickness of the vertical ribs; the Y-shaped reinforcement ribs extend downward from the mud surface to the bottom side of the lower part of the foundation, and the angle between adjacent Y-shaped reinforcement ribs can be 22.5°.

[0027] In this embodiment, the upper part of the foundation can be connected to the wind turbine tower through a flange structure, and the diameter of the lower part of the upper part of the foundation located above the mud surface can be half the diameter of the lower part of the foundation located below the mud surface.

[0028] In this embodiment, a plurality of grouting holes 17 are provided on the upper surface of the outer barrel foundation 2, and the grouting holes can be arranged at a position close to the reinforcing wing plate. A grouting sleeve 18 is passed through the grouting hole, and the grouting sleeve is T-shaped. A circular baffle 19 is laterally provided on the upper part of the grouting sleeve, and the circular baffle is used to abut against the upper surface of the outer barrel foundation to prevent the grouting sleeve from moving downward. The lower part of the grouting sleeve extends downward to the inside of the outer barrel foundation. A plurality of grouting holes are provided on the lower side of the grouting sleeve, which are used to grout into the inside of the outer barrel foundation and form a grouting body 20. The shallow surface soil of the foundation is strengthened, and the bearing capacity can be further improved. The length of the grouting pipe can be adjusted according to actual conditions.

[0029] In this embodiment, the outer barrel foundation 2 includes a barrel skirt 15 and a barrel top plate 16 located above the barrel skirt, and a plurality of reinforcing wing plates 13 are arranged around the center of the barrel top plate above the barrel top plate; the reinforcing wing plates are triangular, and the angle between adjacent reinforcing wing plates can be 45°.

[0030] In this embodiment, a through hole 3 for the thin-walled variable-section single pile foundation is reserved in the middle of the barrel top plate, and a grouting annular plate 12 is arranged on the outer peripheral side of the through hole. The lower part of the grouting annular plate is welded to the barrel top plate, and the diameter of the grouting annular plate increases from bottom to top. An annular reinforcing grouting body 14 is cast inside the grouting annular plate; after the grouting annular plate is installed, an annular conical space is formed between the grouting annular plate and the single pile wall, and an annular reinforcing grouting body can be formed subsequently by grouting; the annular reinforcing grouting body can bond the thin-walled variable-section single pile foundation and the outer barrel foundation, and can transfer the load of the thin-walled variable-section single pile foundation to the outer barrel foundation to form a thin-walled large-diameter single pile-barrel composite pile foundation.

[0031] The cross-section of the outer barrel foundation is annular, and its outer diameter can generally be set to 1.5-3 times the diameter of a single pile according to actual conditions; the barrel skirt can be inserted into the soil to a certain depth.

[0032] In this embodiment, the wall thickness of the thin-walled variable-section single pile foundation is no more than 6 cm, so as to save steel materials, and the required strength can be achieved in combination with the single pile reinforcement structure.

[0033] In this embodiment, the upper part of the foundation is located above the mud surface, and the lower part of the foundation is located below the mud surface. The cross-sectional diameter of the upper part of the foundation decreases from bottom to top and then remains unchanged, and the cross-sectional diameter of the lower part of the foundation is the same.

[0034] In this embodiment, the Y-shaped reinforcing rib 6 is composed of two "V"-shaped connecting ribs 10 and a protruding wing plate 11. The inner ends of the two connecting ribs are connected to the lower part of the foundation, and the outer ends of the two connecting ribs are connected together and connected to the telescopic wing plate; the angle between the two connecting ribs can be 45°~60°. Such a design can not only effectively achieve the purpose of structural reinforcement, but also save steel.

[0035] In this embodiment, multiple annular reinforcement beams are evenly and equidistantly distributed on the outer side of the lower part of the foundation. The annular reinforcement beams include a pair of reinforcement beam cross plates 8 and reinforcement beam vertical plates 9 arranged upper and lower. The upper and lower ends of the reinforcement beam vertical plates are respectively connected to the reinforcement beam cross plates.

[0036] In this embodiment, during construction, the thin-walled variable-section single pile foundation is first driven into the specified depth of the soil layer to control the inclination rate of the pile body and the pile quality of the thin-walled variable-section single pile foundation; after the thin-walled variable-section single pile foundation is installed, the outer barrel foundation is hoisted and installed from the top of the thin-walled variable-section single pile foundation, and after the barrel top plate above the outer barrel foundation contacts the soil layer, grouting is performed at the junction of the thin-walled variable-section single pile foundation and the outer barrel foundation to form an annular reinforced grouting body; if it is necessary to strengthen the soil around the thin-walled variable-section single pile foundation, the grouting pipe can be lowered, and if it is necessary to strengthen the deeper soil, the grouting pipe can be installed with the assistance of certain vibration equipment. After the installation is completed, the grouting pipe is grouted to form a grouting body around the grouting pipe, the shallow surface soil of the foundation is strengthened, and the bearing capacity can be further improved.

[0037] Unless otherwise stated, any technical solution disclosed in the present invention disclosed above, if it discloses a numerical range, then the disclosed numerical range is a preferred numerical range, and any technician in the field should understand that the preferred numerical range is only a numerical value with a more obvious technical effect or representative value among many implementable numerical values. Since there are too many numerical values ​​to be exhaustive, the present invention discloses some numerical values ​​to illustrate the technical solution of the present invention, and the numerical values ​​listed above should not constitute a limitation on the scope of protection of the present invention.

[0038] If the words "first", "second" and so on are used in this article to limit components, those skilled in the art should know that the use of "first" and "second" is only for the convenience of description to distinguish the components. Unless otherwise stated, the above words have no special meaning.

[0039] At the same time, if the above-mentioned invention discloses or involves components or structural parts that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connection using bolts or screws), and can also be understood as: a non-detachable fixed connection (for example, riveting, welding). Of course, the mutual fixed connection can also be replaced by an integrated structure (for example, manufactured by one-piece molding using a casting process) (except when it is obviously impossible to use an one-piece molding process).

[0040] In addition, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in the present invention include states or shapes that are approximate, similar, or close to them.

[0041] Any component provided by the present invention may be assembled from a plurality of separate components, or may be a separate component manufactured by an integral forming process.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A thin-walled large-diameter single pile-barrel composite pile foundation, characterized in that: It includes an outer barrel foundation and a thin-walled variable-section single pile foundation located in the middle of the outer barrel foundation, the thin-walled variable-section single pile foundation includes an upper foundation and a lower foundation, the diameter of the upper foundation is smaller than that of the lower foundation, a plurality of annular plates are arranged at intervals from top to bottom on the inner side of the upper foundation, a plurality of vertical ribs are evenly arranged between the outer wall of the annular plate and the inner wall of the upper foundation, a plurality of annular reinforcement beams are circumferentially arranged on the outer side of the lower foundation, and Y-shaped reinforcement ribs are arranged between adjacent annular reinforcement beams.

2. The thin-walled large-diameter single pile-barrel composite pile foundation according to claim 1, characterized in that: A plurality of grouting holes are arranged on the upper surface of the outer barrel foundation, and a grouting sleeve is passed through the grouting holes. The grouting sleeve is T-shaped, so that the upper part of the grouting sleeve is against the upper surface of the outer barrel foundation, and the lower part of the grouting sleeve extends downward to the inside of the outer barrel foundation. A plurality of grouting holes are opened on the lower side of the grouting sleeve, so as to inject grout into the inside of the outer barrel foundation and form a grouting body.

3. The thin-walled large-diameter single pile-barrel composite pile foundation according to claim 2 is characterized in that: The outer barrel-shaped foundation includes a barrel skirt and a barrel top plate located above the barrel skirt, and a plurality of reinforcing wing plates are arranged above the barrel top plate along the center of the barrel top plate.

4. The thin-walled large-diameter single pile-barrel composite pile foundation according to claim 3 is characterized in that: A through hole is reserved in the middle of the barrel top plate for the installation of a thin-walled variable-section single pile foundation. A grouting annular plate is arranged on the outer peripheral side of the through hole. The lower part of the grouting annular plate is welded to the barrel top plate. The diameter of the grouting annular plate increases from bottom to top, and an annular reinforcing grouting body is cast inside the grouting annular plate.

5. A thin-walled large-diameter single pile-barrel composite pile foundation according to any one of claims 1 to 3, characterized in that: The wall thickness of the thin-walled variable-section single pile foundation is not more than 6 cm.

6. A thin-walled large-diameter single pile-barrel composite pile foundation according to any one of claims 1 to 3, characterized in that: The upper part of the foundation is located above the mud surface, and the lower part of the foundation is located below the mud surface. The cross-sectional diameter of the upper part of the foundation decreases from bottom to top and then remains unchanged, and the cross-sectional diameter of the lower part of the foundation is the same.

7. A thin-walled large-diameter single pile-barrel composite pile foundation according to any one of claims 1 to 3, characterized in that: The Y-shaped reinforcing rib is composed of two "V"-shaped connecting ribs and a protruding wing plate, the inner ends of the two connecting ribs are connected to the lower part of the foundation, and the outer ends of the two connecting ribs are connected together and connected to the telescopic wing plate.

8. A method for installing a thin-walled large-diameter single pile-barrel composite pile foundation according to claim 4, characterized in that: (1) First, the thin-walled variable-section single pile foundation is driven into the specified depth of the soil layer to control the inclination rate and pile quality of the thin-walled variable-section single pile foundation; (2) After the thin-walled variable-section single pile foundation is installed, the outer barrel foundation is hoisted and installed from the top of the thin-walled variable-section single pile foundation. The soil is inserted under the barrel skirt of the outer barrel foundation. After the barrel top plate above the outer barrel foundation contacts the soil layer, grouting is performed at the junction of the thin-walled variable-section single pile foundation and the outer barrel foundation to form a ring-shaped reinforced grouting body; (3) If the soil around the thin-walled variable-section single pile foundation needs to be strengthened, the grouting pipe is lowered. If the deeper soil needs to be strengthened, the grouting pipe is installed with the help of vibration equipment; (4) After the grouting pipe is installed, grouting is performed on the grouting pipe to form a grouting body around the grouting pipe. The shallow surface soil of the foundation is strengthened and the bearing capacity can be further improved.

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