CN113513038B - Concrete single-pile foundation and installation and construction method thereof - Google Patents

Abstract

The invention discloses a concrete single-pile foundation and an installation and construction method thereof, wherein the concrete single-pile foundation comprises a concrete pile serving as a main body of the concrete single-pile foundation, and a conversion section which is fixed at the top of the concrete pile and used for connecting a tower frame of a wind driven generator; the concrete single-pile foundation is horizontally spliced and installed through the V-shaped groove installation tool, so that the installation cost and difficulty are reduced; the buoyancy and the sinking speed of the concrete single-pile foundation are controlled by controlling the air quantity in the concrete single-pile foundation and the self buoyancy of the concrete single-pile foundation, so that the transportation and construction costs and the difficulty of the concrete single-pile foundation are reduced. The installation and construction method of the invention solves the difficult problems of installation, transportation and field construction of the concrete single pile.

Description

Concrete single-pile foundation and installation and construction method thereof

Technical Field

The invention relates to the technical field of offshore wind power generation, in particular to an offshore concrete single-pile foundation, an installation method of the concrete single-pile foundation and a method for marine transportation construction of the concrete single-pile foundation.

Background

The existing offshore fixed foundation scheme has various types such as single-pile foundation, multi-pile foundation, jacket foundation, gravity type foundation, suction tube foundation and the like, wherein the single-pile foundation becomes the main form of offshore wind power foundation by the advantages of simple structure type, mature manufacturing process, convenient construction, low manufacturing cost relative to other foundation types and the like, and the proportion of the single-pile foundation is more than 65% according to statistics.

At present, the existing steel single pile is usually made by rolling steel plates and has the characteristics of large diameter, heavy weight (500-2400 tons) and the like. Recently, the diameter of an ultra-large single-pile foundation in China is reported to be 8.7 meters, the length is 100 meters, the maximum plate thickness is 90 millimeters, and the weight of a single body is 1740 tons.

The existing super large single pile is made of alloy steel plate, and if the weight of the alloy steel plate reaches 2000 tons of steel consumption, the cost is very high. How to reduce the cost of the single pile foundation becomes a research direction, and the reduction of the wall thickness and the increase of the diameter are limited by the diameter-thickness ratio and the manufacturing.

For a mono-pile design, the ratio of diameter to wall thickness is in the range of 90 to 120. If the pipe wall is too thin, the pipe is easy to partially bend during piling to cause pile bursting.

The rolling, welding, transporting and hoisting construction of the super-thick steel plate are difficult. For example, 2000 tons of single piles are generally placed on a roller during processing and storage, and when the wall thickness becomes thinner and thinner, stress concentration is caused, plastic deformation is caused, and the single piles are damaged. When the pipe diameter is large, the dead weight may crush it, causing it to deform greatly. In addition, it is difficult to weld two O-shaped steel cylinders with large diameters.

The super large single pile has a heavy weight and high requirements on the capacity of the hoisting ship, and may need a double 1500-ton crane (with 3000-ton hoisting capacity) or 2000-ton most advanced crane and installation ship.

In conclusion, the steel used for the existing ultra-large single pile is huge, and the production, the manufacture, the transportation, the hoisting and the like are difficult, so that the economy of the ultra-large single pile is challenged by other foundation forms.

Disclosure of Invention

The invention provides a concrete single-pile foundation and an installation and construction method thereof, which adopt a prestressed concrete large-diameter single pile to replace the traditional steel single pile, reduce the cost of the oversized steel single pile, improve the installation and construction difficulty of the single-pile foundation through the installation and construction method, and further exert the advantages of the single-pile foundation on deep sea and large-capacity units.

In order to achieve the above object, the present invention provides a concrete mono-pile foundation, comprising:

the concrete pile forms a main body of the concrete single-pile foundation;

the conversion section is fixedly arranged at the top of the concrete pile through a prestressed cable and grouting and is used for connecting a wind driven generator tower;

the concrete pile comprises a plurality of prefabricated units which are fixedly connected along the height direction of the wind driven generator tower, and two adjacent prefabricated units are arranged in a sealing mode.

Furthermore, the prefabricated unit is of a hollow structure with two closed ends, and two exhaust holes are formed in the side wall of the prefabricated unit; and the exhaust hole positioned at the top end of the concrete pile is provided with an exhaust valve, the exhaust hole positioned at the bottom end of the concrete pile is plugged in the transportation process, and the rest exhaust holes on the concrete pile are communicated.

Furthermore, a plurality of the prefabricated units are overlapped and fixedly connected through prestressed cables; a plurality of first installation pore channels are uniformly arranged in the side wall of the prefabricated unit so as to install the prestressed cable.

Further, the conversion section is fixedly connected with the concrete pile through a prestressed cable; a plurality of second mounting holes are uniformly formed in the side wall of the conversion section, and the number and the size of the second mounting holes are matched with those of the first mounting holes in the prefabricated units; and the prestressed cable sequentially passes through the second mounting pore of the conversion section and the first mounting pore of each prefabricated unit to connect the conversion section and the concrete pile into a whole.

Furthermore, an upper anchorage device and a lower anchorage device are respectively arranged at two ends of the prestressed cable.

Further, the prefabricated units are cylinders or polygonal bodies.

Further, the conversion section is connected with the wind driven generator tower through an anchor bolt.

Further, the concrete single-pile foundation further comprises a connecting section, and the connecting section is fixed at the bottom of the concrete pile through a prestressed cable.

Further, the connection segment includes: the annular wall, the flange fixedly connected with the annular wall and a plurality of reinforcing ribs fixedly arranged between the annular wall and the flange; a plurality of first mounting holes are uniformly formed in the flange, and the number and the size of the first mounting holes are matched with those of the first mounting pore channels in the prefabricated units; the prestressed cable sequentially penetrates through the second mounting pore of the conversion section, the first mounting pore of each prefabricated unit and the first mounting hole in the flange, and the conversion section, the concrete pile and the connecting section are connected into a whole.

The invention also provides an installation method of the concrete single-pile foundation, which comprises the following steps:

positioning the conversion section in a V-shaped groove installation tool, and sequentially placing a plurality of prefabricated units and connecting sections;

sequentially adjusting the angles and the positions of each prefabricated unit and the connecting section to enable the second mounting pore on the conversion section, the first mounting pore on each prefabricated unit and the first mounting pore on the connecting section to be aligned with each other; the connection section is tightly attached to the prefabricated units, the prefabricated units and the conversion section, and sealant is coated on the contact surface;

sequentially penetrating a prestressed cable through the first mounting hole, the first mounting pore channels and the second mounting pore channels, mounting an upper anchorage device and a lower anchorage device at two ends of the prestressed cable, and tensioning the prestressed cable;

after tensioning and pre-tightening operation is carried out on the prestressed cable, grouting is carried out in each first installation pore channel, each second installation pore channel and each first installation pore channel, so that the conversion section, each prefabricated unit and the connecting section are fixedly connected to form a concrete single-pile foundation;

and an exhaust valve is arranged on the exhaust hole at the top end of the concrete single-pile foundation, so that the exhaust hole at the bottom end of the concrete single-pile foundation is plugged, and the rest exhaust holes are communicated.

Furthermore, the V-shaped groove installation tool comprises two inclined side surfaces, each inclined side surface is provided with a concave-convex surface, and a groove is formed between two adjacent convex surfaces; the concave-convex surfaces of the two inclined side surfaces are arranged opposite to each other.

The invention also provides a construction method of the concrete single-pile foundation, which comprises the following steps:

floating the concrete single-pile foundation on the sea surface and dragging the concrete single-pile foundation to a machine site;

opening an exhaust hole plugged at the bottom end of the concrete single-pile foundation, lifting the top end of the concrete single-pile foundation to enable the concrete single-pile foundation to sink, and controlling the exhaust of the concrete single-pile foundation through an exhaust valve so as to control the buoyancy and sinking speed of the concrete single-pile foundation;

when the concrete single-pile foundation is inserted into the seabed, the exhaust valve is fully opened, and the concrete single-pile foundation is completely filled with seawater;

grouting operation, fixing the concrete single pile foundation on the seabed.

The invention has the following advantages:

the concrete single-pile foundation is adopted to replace the traditional steel single-pile foundation, steel is saved, and the cost of the oversized steel single-pile foundation is reduced. The concrete single pile foundation contains a plurality of prefabricated unit, and the prefabricated unit can use the mould to pour and form, and the preparation is easy, need not use the main equipment.

According to the invention, the concrete single-pile foundation is installed through the V-shaped groove installation tool, the construction is simple, the vertical hoisting construction is not needed, the high-altitude operation is also not needed, and the operation is safe and convenient.

The invention utilizes the buoyancy of the concrete single-pile foundation to float and drag on the sea surface, solves the transportation and installation problems of the ultra-heavy single-pile foundation, does not need large transportation and hoisting ships, and has easy operation and lower transportation and construction cost.

Drawings

Fig. 1 is a schematic view of a non-driven concrete mono-pile foundation fixed to the seabed.

Fig. 2 is a schematic view of a driven concrete mono-pile foundation secured to the seabed.

Fig. 3 is a schematic structural view of a non-driven concrete mono-pile foundation.

Fig. 4 is a partially enlarged view of a portion a in fig. 1.

Fig. 5 is a schematic structural view of a driving type concrete mono-pile foundation.

Fig. 6 is a partially enlarged view of C in fig. 2.

Fig. 7 is a schematic structural view of the V-groove mounting tool.

Fig. 8 is an installation schematic diagram of a concrete mono-pile foundation.

Fig. 9 is a schematic construction view of a concrete mono-pile foundation.

Detailed Description

The invention is described in further detail below with reference to the figures and specific examples. Advantages and features of the present invention will become apparent from the following description and from the claims. It is to be noted that the drawings are in a very simplified form and are each provided with a non-precise ratio for the purpose of facilitating and clearly facilitating the description of the embodiments of the present invention.

The invention provides a concrete single-pile foundation, which adopts a prestressed concrete large-diameter single-pile foundation to replace a traditional steel single-pile foundation. The manufacturing cost of the concrete raw material is low, generally 50% of the manufacturing cost of the steel plate, and the manufacturing cost of the large-diameter single-pile foundation manufactured by adopting the concrete is greatly reduced. The traditional steel single-pile foundation needs to adopt large-scale equipment such as plate rolling equipment and the like and needs to be welded by steel plates. The concrete single-pile foundation is easy to construct, only needs to be formed by pouring through a mould, and does not need large-scale equipment. And the concrete ring has small diameter-thickness ratio, large rigidity, small transportation and movement deformation, large damping ratio and excellent damping performance, and the buckling problem can be not considered.

According to whether the single-pile foundation is directly driven into the seabed, the concrete single-pile foundation is divided into two structures: a non-driven concrete single-pile foundation and a driven concrete single-pile foundation. As shown in fig. 1, during the construction of the non-driven concrete single-pile foundation, a hole is drilled in the seabed, the non-driven concrete single-pile foundation is placed in the seabed hole 7, and finally, the concrete single-pile foundation and the side gap of the seabed hole 7 are grouted and fixed. As shown in fig. 2, during the construction of the driven-in type concrete single-pile foundation, a section of steel pile 6 is driven into the seabed in advance, and then the driven-in type concrete single-pile foundation and the steel pile 6 are fixedly connected by grouting.

Fig. 3 is a schematic structural view of a non-driven concrete mono-pile foundation. The non-driven type concrete mono-pile foundation includes:

a concrete pile 4 as a main body of the concrete single pile foundation;

and the conversion section 3 is fixed on the top of the concrete pile 4 through a prestressed cable 42 and grouting, and the conversion section 3 is used for connecting the wind driven generator tower 1.

The concrete pile 4 comprises a plurality of prefabricated units 41 fixedly connected through prestressed cables 42, the prefabricated units 41 are arranged in a stacked mode in the height direction of the tower, and two adjacent prefabricated units 41 are arranged in a sealing mode through sealing epoxy glue. The prefabricated unit 41 is a hollow structure with two closed ends, and optionally, the prefabricated unit 41 is a cylinder or a polygon. Preferably, the prefabricated unit 41 is a cylinder. The lateral wall of each prefabricated unit 41 is provided with at least two exhaust holes 45, the exhaust holes at the top end of the concrete pile 4 are provided with exhaust valves 9, the exhaust holes at the bottom end of the concrete pile 4 are plugged during transportation, and the exhaust holes of two adjacent prefabricated units 41 are communicated. In this embodiment, the side wall of the prefabricated unit 41 is provided with two vent holes 45, the vent hole 45 positioned at the top end of the concrete pile 4 is provided with the vent valve 9, the vent hole 45 positioned at the bottom end of the concrete pile 4 is plugged in the transportation process, and two adjacent vent holes 45 in two adjacent prefabricated units 41 are communicated. A plurality of first installation holes 46 are further formed in the side wall of the prefabricated unit 41 to facilitate installation of the prestressed cable 42 and subsequent grouting.

A plurality of second mounting holes are also formed in the side wall of the conversion section 3, and the number and the size of the second mounting holes are matched with those of the first mounting holes 46 on the prefabrication unit 41. The prestressed cable 42 sequentially passes through the second mounting hole on the conversion section 3 and the first mounting hole 46 on each prefabricated unit 41 in the concrete pile 4, and the conversion section 3 and the concrete pile 4 are connected into a whole. An upper anchorage 43 and a lower anchorage 44 are respectively installed at both ends of the prestressed cable 42 so as to tension and pre-stress the prestressed cable 42.

The conversion section 3 is of a concrete structure with a manhole in the middle of the upper end and an open lower end, and a plurality of fixed pore canals are further arranged on the side wall of the conversion section. The conversion section 3 is connected with a tower frame 1 of the wind driven generator through anchor bolts 2, and the anchor bolts 2 are located in the conversion section 3.

Fig. 4 shows a schematic view of the connection of anchor bolts 2 to conversion section 3 and tower 1. Anchor bolt 2 contains anchor slab 24, anchor slab 23 down and fixes a plurality of stock 22 between the two, it sets up to go up anchor slab 24 the upper end of changeover portion 3, stock 22 sets up in the fixed orifices of changeover portion 3, anchor slab 23 is located down inside the changeover portion 3. The number and size of the upper anchor rods 22 match the number and size of the fixing tunnels. The anchor rod 22 sequentially penetrates through the T flange 12 at the tower bottom of the wind driven generator tower 1, the upper anchor plate 24, the fixing hole channel of the conversion section 3 and the lower anchor plate 23, and the conversion section 3 and the wind driven generator tower 1 are fixedly connected into a whole through the upper nut 21 and the lower nut 21.

As shown in fig. 2 and 5, the driven concrete mono-pile foundation includes:

a concrete pile 4;

the conversion section 3 is fixed at the top of the concrete pile 4, and the conversion section 3 is used for connecting a wind driven generator tower frame 1; and

and the connecting section 5 is fixed at the bottom of the concrete pile 4 through a prestressed cable 42, and the connecting section 5 is used for fixedly connecting a steel pile 6.

The upper structure of the driven-in type concrete single pile foundation, i.e. the concrete pile 4 and the conversion section 3, is the same as the structure of the non-driven-in type concrete single pile foundation.

The connection section 5 includes: the flange comprises a ring wall 53, a flange 51 fixedly connected with the ring wall 53, and a plurality of reinforcing ribs 52 fixedly arranged between the ring wall 53 and the flange 51; the flange 51 is uniformly provided with a plurality of first mounting holes 54, and the prestressed cable 42 sequentially passes through the second mounting hole of the conversion section 3, the first mounting hole 46 of each prefabricated unit 41 and the first mounting hole 54 on the flange 51 to connect the conversion section 3, the concrete pile 4 and the connecting section 5 into a whole.

The connecting section 5 is fixedly connected with the steel pile 6 through grouting. Fig. 6 shows a schematic view of the connection of the connecting segment 5 and the steel pile 6, wherein the steel pile 6 comprises a pile wall 61 and a flange ring 62 fixed at the bottom of the pile wall 61. The pile wall 61 is larger in size than the ring wall 53 of the connecting section 5, and the flange ring 62 is used to support and position the ring wall 53 of the connecting section 5. The connecting section 5 is installed in the steel pile 6, and then grouting is performed in a side gap between the annular wall 53 of the connecting section 5 and the pile wall 61 of the steel pile 6 to fixedly connect the connecting section 5 and the steel pile 6.

Because the offshore situation is severe, the long-time field construction at the site cannot be performed according to the traditional concrete structure, therefore, the invention provides the method for installing the concrete single-pile foundation constructed on the shore, so that the difficult problem of installing the offshore concrete single-pile foundation is solved, and the installation cost is reduced.

The installation method of the concrete single-pile foundation is realized through a V-shaped groove installation tool 8. As shown in fig. 7, the V-shaped groove installation tool 8 includes two inclined side surfaces, each inclined surface has a concave-convex surface, a groove 81 is disposed between two adjacent convex surfaces, the concave-convex surfaces of the two inclined side surfaces are disposed opposite to each other, that is, the convex surfaces of the two inclined surfaces are disposed opposite to each other, and the grooves are also disposed opposite to each other. When the concrete single-pile foundation is installed on the V-shaped groove installation tool 8, the conversion section 3, the prefabricated unit 41 or the connecting section 5 is hoisted into the V-shaped groove installation tool 8 through the hanging belt, and the conversion section 3, the prefabricated unit 41 or the connecting section 5 is dragged through the hanging belt so as to adjust the position of the conversion section 3, the prefabricated unit 41 or the connecting section 5 in the V-shaped groove installation tool 8. The inclined side face of the V-shaped groove installation tool 8 is provided with a convex surface with a large area for supporting the conversion section 3, the prefabricated unit 41 and the connecting section 5 together with the bottom face of the V-shaped groove installation tool 8, and the groove 81 with a small area is arranged, so that a gap space is formed in the V-shaped groove installation tool, and the hanging strip can be conveniently installed and detached. The V-shaped groove installation tool 8 can be horizontal during manufacturing and can also be obliquely cut at a certain angle.

As shown in fig. 8, which is a schematic view of the installation of the concrete single-pile foundation, the installation method of the non-driven concrete single-pile foundation specifically includes the following steps:

A. positioning the conversion section 3 and placing the conversion section into a V-shaped groove installation tool 8;

B. putting the first prefabricated unit, rotating the angle of the first prefabricated unit to align the first mounting hole 46 on the first prefabricated unit with the second mounting hole of the conversion section 3, adjusting the position of the first prefabricated unit to enable the first prefabricated unit to be tightly combined with the conversion section 3, and smearing sealant on the contact surface of the first prefabricated unit and the conversion section 3 for sealing; specifically, the first prefabricated unit can be directly placed into the V-shaped groove mounting tool 8, the angle of the prefabricated unit is rotated to align the first mounting hole 46 of the first prefabricated unit with the second mounting hole of the conversion section 3, the contact surface of the first prefabricated unit and the conversion section 3 is coated with sealant for sealing, and the prefabricated unit is axially dragged to enable the first prefabricated unit and the conversion section 3 to be tightly combined;

C. placing the second pre-form unit and rotating the second pre-form unit at an angle such that the first mounting aperture 46 of the second pre-form unit is aligned with the first mounting aperture 46 of the first pre-form unit; adjusting the position of the second prefabricated unit to enable the second prefabricated unit to be tightly combined with the first prefabricated unit, and smearing sealant on the contact surface of the second prefabricated unit and the first prefabricated unit for sealing; in general, the installation accuracy of the prefabricated unit 41 meets the operation requirement, and if the error is large, a gasket can be added on the V-shaped side surface of the V-shaped groove installation tool 8;

D. repeating the above operations until the placement of all prefabricated units 41 is completed;

E. the prestressed cable 42 sequentially passes through a second mounting hole of the conversion section 3 and a first mounting hole 46 of each prefabricated unit 41, and then an upper anchorage device 44 and a lower anchorage device 44 are respectively mounted at two ends of the prestressed cable 42, and then the prestressed cable 42 is tensioned and pre-tensioned;

F. grouting each second mounting hole and each first mounting hole 46 along the prestressed cable 42, and fixedly connecting the connecting section 5 and each prefabricated unit 41 into a whole;

H. two adjacent vent holes 45 on two adjacent prefabricated units 41 are communicated, a vent valve 9 is arranged on the vent hole 45 close to the conversion section 3, and the vent hole 45 close to the connecting section 5 is blocked; and finishing the installation of the non-driven type concrete single-pile foundation.

The method for installing the driving-in type concrete single-pile foundation on the bank by adopting the V-shaped groove installation tool 8 is basically the same as the installation method of a non-driving-in type concrete single-pile foundation, and has the following differences: after the conversion section 3 and the prefabricated units 41 are placed, the connecting section 5 is placed in the V-shaped groove installation tool 8, the angle of the connecting section 5 is rotated to enable the first installation hole 54 on the connecting section to be aligned with the first installation hole 46 of the adjacent prefabricated unit 41, the position of the connecting section 5 is adjusted to enable the connecting section to be tightly attached to the adjacent prefabricated unit 41, and the contact surface of the connecting section 5 and the adjacent prefabricated unit 41 is coated with sealant for sealing; then, the prestressed cable 42 sequentially passes through the second installation hole of the transition section 3, the first installation hole 46 of each prefabricated unit 41 and the first installation hole 54 of the connecting section 5, and then the upper anchor 44 and the lower anchor 44 are respectively installed at both ends of the prestressed cable 42 to stretch the prestressed cable 42; and grouting the second mounting hole, the first mounting hole 46 and the first mounting hole 54 along the prestressed cable 42 to fixedly connect the connecting section 5, the prefabricated units 41 and the conversion section 3 into a whole.

The V-shaped groove installation tool 8 is used for installing the concrete single-pile foundation, construction is simple and convenient, a large crane is not needed, the operation surface is only the diameter height of the prefabricated unit 41, aerial operation is not needed, construction requirements are reduced, and installation cost is saved. Moreover, when the V-groove installation tool 8 is manufactured, the straightness and the position accuracy of the V-groove installation tool 8 are ensured, and the conversion section 3, the prefabrication unit 41 and the connection section 5 are placed in the V-groove installation tool 8, so that the straightness, the coaxiality and the like can be ensured.

As compared with traditional steel pile single pile foundation, the concrete single pile foundation is generally 3-4 times of the weight of the steel pile single pile foundation. If the concrete single-pile foundation is positioned and thrown into the sea according to the traditional construction mode, the required hoisting equipment and cost are increased rapidly, and even the construction of the concrete single-pile foundation cannot be completed. Therefore, the invention provides a construction method of a concrete single-pile foundation, which utilizes the self buoyancy of the concrete single-pile foundation to float and drag the concrete single-pile foundation to a preset construction machine position, controls the sinking speed of the concrete single-pile foundation by controlling the buoyancy of the concrete single-pile foundation when the concrete single-pile foundation is hoisted, and fixes the concrete installation foundation after sinking to the seabed so as to complete the construction of the concrete single-pile foundation in a preset sea area.

As shown in fig. 9, which is a schematic construction diagram of a concrete single-pile foundation, the construction method of the concrete single-pile foundation specifically includes the following steps:

a. floating the concrete single-pile foundation on the sea surface and dragging the concrete single-pile foundation to a machine site; specifically, the concrete single-pile foundation is dragged to the sea surface from the V-shaped groove installation tool 8, at the moment, the exhaust holes 45 in the concrete single-pile foundation are sealed, and float on the sea surface by virtue of buoyancy generated by the concrete per se and are dragged to the machine site;

b. the exhaust hole 45 blocked at the bottom end of the concrete single-pile foundation is opened, the top end of the concrete single-pile foundation is lifted to sink, and the exhaust of the concrete single-pile foundation is controlled through the exhaust valve 9 so as to control the buoyancy and sinking speed of the concrete single-pile foundation; specifically, after the concrete single-pile foundation is dragged to a machine position, the exhaust hole 45 at the bottom end of the concrete single-pile foundation is opened, the hoisting ship hoists the upper end of the concrete single-pile technology, the exhaust hole 45 at the bottom end of the concrete single-pile foundation starts to feed water, and the concrete single-pile foundation starts to sink; air in the concrete single-pile foundation is exhausted through an exhaust hole 45 positioned at the top end of the concrete single-pile foundation, and the buoyancy of the concrete single-pile foundation is controlled by controlling the exhaust gas quantity of the exhaust valve 9, so that the concrete single-pile foundation is slowly inclined and sunk;

c. when the concrete single-pile foundation is inserted into the seabed, the exhaust valve 9 is fully opened, and the concrete single-pile foundation is completely filled with seawater; specifically, after the concrete single-pile foundation is inserted into a steel pile 6 or a seabed hole 7 in the seabed, the exhaust valve 9 is fully opened, and seawater completely fills the concrete single-pile foundation;

d. grouting operation, namely fixing the concrete single-pile foundation on the seabed; specifically, the concrete single-pile foundation is fixed on the seabed by grouting in the side gap between the concrete single-pile foundation and the steel pile 6 or grouting in the side gap between the concrete single-pile foundation and the seabed hole 7.

The buoyancy of the concrete single-pile foundation is controlled by controlling the air volume in the concrete single-pile foundation, so that the transportation and construction problems of the ultra-heavy single-pile foundation are solved, a large-scale transportation and hoisting ship is not needed, the operation is easy, and the transportation and construction cost is low.

While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. Various modifications and alterations to this invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be determined from the following claims.

Claims (6)

1. A concrete mono-pile foundation, comprising:

concrete piles;

the conversion section is fixed at the top of the concrete pile and is used for connecting a wind driven generator tower;

the concrete pile comprises a plurality of prefabricated units which are fixedly connected along the height direction of the wind driven generator tower, and two adjacent prefabricated units are arranged in a sealing manner;

the prefabricated unit is of a hollow structure with two closed ends, and two exhaust holes are formed in the side wall of the prefabricated unit; the vent hole positioned at the top end of the concrete pile is provided with a vent valve, the vent hole positioned at the bottom end of the concrete pile is plugged in the transportation process, and the rest vent holes on the concrete pile are communicated;

the plurality of prefabricated units are fixedly connected through prestressed cables, and a plurality of first installation pore channels are uniformly arranged in the side walls of the prefabricated units so as to install the prestressed cables;

the concrete single-pile foundation also comprises a connecting section, and the connecting section is fixed at the bottom of the concrete pile through a prestressed cable;

the connection section includes: the annular wall, the flange fixedly connected with the annular wall and a plurality of reinforcing ribs fixedly arranged between the annular wall and the flange; a plurality of first mounting holes are uniformly formed in the flange, and the number and the size of the first mounting holes are matched with those of first mounting holes in the prefabricated units; a plurality of second mounting pore channels are uniformly arranged in the side wall of the conversion section; and the prestressed cable sequentially passes through the second mounting pore of the conversion section, the first mounting pore of each prefabricated unit and the first mounting hole on the flange, and the conversion section, the concrete pile and the connecting section are connected into a whole.

2. The concrete mono-pile foundation of claim 1, wherein said transition section is fixedly connected to said concrete pile by means of a pre-stressed cable; the number and the size of the second mounting pore channels are matched with those of the first mounting pore channels on the prefabricated units; and the prestressed cable sequentially passes through the second mounting pore of the conversion section and the first mounting pore of each prefabricated unit to connect the conversion section and the concrete pile into a whole.

3. The concrete mono-pile foundation of claim 2, wherein an upper anchorage and a lower anchorage are respectively installed at both ends of the prestressed cable.

4. An installation method for a concrete mono-pile foundation according to any one of claims 1 to 3, characterized by comprising the following steps:

positioning the conversion section in a V-shaped groove installation tool, and then sequentially placing a plurality of prefabricated units and connecting sections;

sequentially adjusting the angles and the positions of each prefabricated unit and the connecting section to enable the second mounting hole on the conversion section, the first mounting hole on each prefabricated unit and the first mounting hole on the connecting section to be aligned with each other; the connecting section is tightly attached to the prefabricated units, the prefabricated units and the conversion section, and sealant is coated on the contact surface;

sequentially penetrating a prestressed cable through a first mounting hole, each first mounting pore passage and a second mounting pore passage, mounting an upper anchorage device and a lower anchorage device at two ends of the prestressed cable, and tensioning the prestressed cable;

grouting into each first mounting hole, each second mounting hole and each first mounting hole so as to fixedly connect the conversion section, each prefabricated unit and the connecting section into a concrete single-pile foundation;

and an exhaust valve is arranged on the exhaust hole positioned at the top end of the concrete single-pile foundation, so that the exhaust hole positioned at the bottom end of the concrete single-pile foundation is plugged, and the rest exhaust holes are communicated.

5. The mounting method of claim 4, wherein the V-groove mounting tool comprises two inclined side surfaces, each inclined side surface having a concave-convex surface, a groove being provided between two adjacent convex surfaces; the concave-convex surfaces of the two inclined side surfaces are arranged opposite to each other.

6. A construction method for realizing the concrete mono-pile foundation according to any one of claims 1 to 3, characterized by comprising the steps of:

floating the concrete single-pile foundation on the sea surface and dragging the concrete single-pile foundation to a machine site;

opening an exhaust hole plugged at the bottom end of the concrete single-pile foundation, lifting the top end of the concrete single-pile foundation to enable the concrete single-pile foundation to sink, and controlling the exhaust of the concrete single-pile foundation through an exhaust valve so as to control the buoyancy and sinking speed of the concrete single-pile foundation;

when the concrete single-pile foundation is inserted into the seabed, the exhaust valve is fully opened, and seawater completely fills the concrete single-pile foundation;

grouting operation, fixing the concrete single pile foundation on the seabed.

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