CN106836265A - A kind of gravity type bucket foundation with skirtboard and its construction method - Google Patents

Abstract

The invention belongs to the field of offshore wind power foundations, and discloses a gravity-type cylindrical foundation with aprons and a construction method thereof, including a steel cylindrical structure, a reinforced concrete top cover, and a reinforced concrete transition section; steel bars are arranged on the edge of the reinforced concrete top cover The concrete apron, the lower part of the reinforced concrete roof and the steel tubular structure are connected with shear nails, and the upper part is connected with the reinforced concrete transition section by pouring; during construction, the bottom of the steel apron sinks into the sea through the sinking of its own weight and negative pressure in sequence. The bed, after sinking into place, throws ballast stones between the reinforced concrete apron and the reinforced concrete transition section. The invention has a simple and compact structure, convenient and fast construction, and the ballast stones thrown between the reinforced concrete skirt board and the reinforced concrete transition section can effectively improve the anti-overturning ability and anti-scouring ability of the foundation, and its installation process can be self-floating towing and sinking The sinking process does not require large-scale equipment, and has the characteristics of low cost and high construction efficiency.

Description

A kind of gravity type barrel foundation with apron and its construction method

technical field

The invention belongs to the field of offshore wind power foundations, and in particular relates to a gravity-type cylindrical foundation for offshore wind power and a construction method thereof.

Background technique

At present, in offshore equipment projects such as offshore wind power projects, the foundation structure usually includes: monopile, tripod, jacket foundation, gravity foundation, negative pressure cylinder foundation and floating platform structure. These foundations generally require large-scale equipment for transportation and installation, resulting in high costs for construction in sea areas, and the ability of the above foundations to resist seabed erosion is limited.

Offshore foundation structures are often faced with the scouring effect of reciprocating ocean currents, and scouring has a certain degree of influence on the bearing capacity of foundation structures. Therefore, how to improve the conventional composite cylindrical foundation structure so that it has stronger anti-scouring and anti-overturning capabilities, so as to maximize the bearing capacity of the foundation structure and ensure the safety and stability of the foundation structure during operation is an important issue for marine foundation structures. An important part of the design.

Contents of the invention

Based on the requirements of seabed erosion resistance of offshore wind power foundation structures, the present invention provides a gravity-type barrel foundation with aprons and a construction method thereof. The increase of the skirt board can increase the anti-overturning and anti-scouring ability of the foundation during normal use, and can significantly reduce the construction cost of the foundation.

In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

A gravity-type cylindrical foundation with a skirt, including a steel cylindrical structure, a reinforced concrete roof, and a reinforced concrete transition section;

A plurality of compartment plates are arranged inside the steel tubular structure, so that the steel tubular structure and the compartment plates form a plurality of sealed compartments with bottom openings;

The lower part of the reinforced concrete roof and the steel tubular structure are connected by shear nails; the edge of the reinforced concrete roof is provided with a reinforced concrete skirt plate extending upward, and the reinforced concrete skirt plate is connected to the reinforced concrete roof One-time pouring; the reinforced concrete top cover is arranged with a suction pipe corresponding to each sealed sub-compartment;

The reinforced concrete transition section is poured and connected to the upper part of the reinforced concrete roof.

Preferably, the steel cylindrical structure has a diameter of 10-50m and a wall thickness of 10-100mm.

Preferably, the sealed compartment formed by the steel cylindrical structure and the compartment plate is a honeycomb compartment structure, including a regular hexagonal compartment in the center and six identical side compartments evenly arranged around it. cabin; the regular hexagonal subdivision and side subdivision have equal side lengths, which are 0.25 times the diameter of the steel cylindrical structure.

Preferably, the height of the partition plate is the same as that of the wall of the cylindrical foundation, and the thickness is the same as that of the wall of the cylindrical foundation.

Preferably, the diameter of the reinforced concrete roof is 3-5m larger than that of the steel cylindrical structure, and the thickness of the reinforced concrete roof is 0.2-0.6m.

Preferably, the reinforced concrete apron has a height of 0.5-1.5m and a thickness of 0.2-0.5m.

Preferably, the height of the reinforced concrete transition section is 5-10 meters, the thickness is 0.1-2 m, the diameter of the top surface is less than or equal to the diameter of the bottom surface, and the wall surface is an arc-shaped concave surface with a curvature of 1/60-1/ 10.

Preferably, the reinforced concrete transition section is a prestressed concrete structure, and prestressed steel bars are arranged inside, the reinforcement ratio is not less than 0.3%, and the tensile stress of the prestressed steel bars is not less than 0.75 times the yield stress of the steel bars.

The construction method of the above-mentioned gravity-type cylindrical foundation with a skirt plate is carried out according to the following steps:

(1) Move the gravity-type cylindrical foundation with the tower and fan assembled into the water, so that it floats on the water as a whole;

(2) Floating and consigning the gravity-type cylindrical foundation to the designated construction site, and initially leveling the seabed at the construction site;

(3) Open the suction pipe on the reinforced concrete top cover, so that the gravity type cylindrical foundation sinks to the seabed by its own weight;

(4) After the self-weight sinking stops, the pumping pipe on the reinforced concrete roof is used to pump water inside the steel tubular structure, so that the gravity-type tubular foundation continues to sink through negative pressure sinking;

(5) After the gravity-type cylindrical foundation sinks into place, ballast stones are thrown between the reinforced concrete skirt board and the reinforced concrete transition section, and the construction of the entire structure is completed.

The beneficial effects of the present invention are:

The gravity-type cylindrical foundation with skirt and its construction method of the present invention have simple and compact foundation structure, convenient and fast construction, and ballast stones thrown between the reinforced concrete skirt and reinforced concrete transition section can effectively improve the resistance of the foundation. Overturning ability and anti-scouring ability, its installation process can be self-floating towing and sinking, the sinking process does not require large equipment, and has the characteristics of low cost and high construction efficiency.

Description of drawings

Fig. 1 is the front view of the gravity-type cylindrical foundation with apron provided by the present invention;

Fig. 2 is the bottom view of steel tubular structure;

Fig. 3 is the front view of steel cylindrical structure;

Fig. 4 is a front view of the gravity-type cylindrical foundation provided by the present invention after construction is completed.

In the figure: 1. Reinforced concrete transition section; 2. Ballast stones; 3. Reinforced concrete skirt; 4. Reinforced concrete roof; 5. Steel tubular structure;

detailed description

In order to further understand the invention content, characteristics and effects of the present invention, the following examples are given, and detailed descriptions are as follows in conjunction with the accompanying drawings:

As shown in Fig. 1 to Fig. 3, this embodiment provides a gravity-type cylindrical foundation with apron, which is mainly composed of reinforced concrete transition section 1, reinforced concrete top cover 4, and steel cylindrical structure 5.

The steel cylindrical structure 5 has a diameter of 10-50m and a wall thickness of 10-100mm. In order to facilitate foundation sinking and leveling, a plurality of subdivision plates 7 are arranged inside the steel cylindrical structure 5, so that the steel cylindrical structure 5 and the subdivision plates 7 form a plurality of sealed subdivisions with bottom openings. Preferably, the steel cylindrical structure 5 and the subdivision plate 7 form a honeycomb subdivision structure, including a regular hexagonal subdivision in the center and six identical side subdivisions uniformly arranged around it. The side lengths of the regular hexagonal subdivision and the side subdivision are equal, which is 0.25 times the diameter of the steel cylindrical structure 5, as shown in Figure 2. The seven sub-compartments in the sub-compartment structure are well sealed to each other except for the opening at the bottom to ensure that they do not overlap with each other, and a pipeline with a switch is reserved on the top of each sub-compartment for applying negative pressure in the cabin respectively. The top of the subdivision plate 7 is welded and fixed with the inner top wall of the steel tubular structure 5, the height of the subdivision plate 7 is the same as the height of the main tube of the steel tubular structure 5, and the thickness is the same as the wall of the steel tubular structure 5.

The diameter of the reinforced concrete top cover 4 is 3-5 m larger than that of the steel tubular structure 4 . The thickness selection range of the reinforced concrete roof 2 is 0.2-0.6m. On the edge of the reinforced concrete roof 4, a reinforced concrete apron 3 extending upwards is set with a height of 0.5-1.5m and a thickness of 0.2-0.5m. The tendon rate is not less than 0.3%.

The upper part of the reinforced concrete roof 4 is poured and connected with the reinforced concrete transition section 1, and the lower part is connected with the steel tubular structure 5 by using shear nails. Seven pumping pipes 6 are arranged on the reinforced concrete roof 4 , one of which is respectively provided for each of the seven sub-compartments of the steel tubular structure 5 . The diameter of the suction pipe 5 is 20-200 mm, the top of which passes through the reinforced concrete roof 4 and the bottom extends to the inside of the steel cylindrical structure 5 .

The specific structure of the reinforced concrete transition section 1 is not limited, preferably a curved reinforced concrete transition section 1 with a height of 5 to 10 meters and a thickness of 0.1 to 2 m, the diameter of the top surface is less than or equal to the diameter of the bottom surface, and the wall surface is arc-shaped Concave surface, the curvature of the surface is 1/60～1/10. Reinforced concrete transition section 1 is a prestressed concrete structure, and prestressed steel bars are arranged inside, the reinforcement ratio is not less than 0.3%, and the tensile stress of the prestressed steel bars is not less than 0.75 times the yield stress of the steel bars.

The present invention also provides a construction method for the above-mentioned gravity-type cylindrical foundation with aprons, which is carried out according to the following steps:

a. Onshore prefabricated steel tubular structure 5, welding subdivision plates 7 inside the steel tubular structure 5;

b. Utilize the thin-wall profiled steel plate as the formwork of the reinforced concrete roof 4 and the reinforced concrete apron 3 on the upper part of the steel tubular structure 5 and arrange the reinforcement, pour the reinforced concrete roof 4 and the reinforced concrete apron 3, and place them on the reinforcement Concrete roof 2 is reserved for connecting steel bars with reinforced concrete transition section 1;

c. Connect the reinforced concrete top cover 4 and the steel cylindrical structure 5 with shear nails, install the water pipe 6 on the reinforced concrete top cover 4 at the same time, and check the gravity of the reinforced concrete top cover 4 and the steel cylindrical structure 5 The airtightness test of the structure;

d. After the air tightness meets the requirements, arrange the formwork of the reinforced concrete transition section 1 and bind the steel bars, and carry out concrete pouring of the reinforced concrete transition section 1;

e. After the construction of the reinforced concrete transition section 1 is completed and the design strength requirements are met, the tower and fan are assembled;

f. Use a crane to move the gravity-type cylindrical foundation assembled with the tower and fan into the water, and the self-floating ability of the gravity-type cylindrical foundation makes it float on the water as a whole;

g. Use the tugboat to drag the gravity-type barrel foundation to the designated construction site, and at the same time carry out preliminary leveling of the seabed at the construction site;

h. Open the suction pipe 6 on the reinforced concrete top cover 4, so that the gravity type cylindrical foundation sinks to the seabed by its own weight; after the self-weight sinking stops, extract the excess water in the steel cylindrical structure 5 through the suction pipe 6, and use The pumping of the water body realizes the generation of negative pressure in the steel cylindrical structure 5, that is, the negative pressure sinking process;

During the sinking process, the reinforced concrete roof 4 should be kept level with the seabed, and if the gravity-type cylindrical foundation is tilted, different cabin pressures should be applied to each sub-chamber for leveling through the feed-control system;

i. After the gravity-type cylindrical foundation sinks into place, ballast stones 2 are thrown between the reinforced concrete skirt 3 and the reinforced concrete transition section 1, and the construction of the entire structure is completed, as shown in Figure 4.

Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are only illustrative and not restrictive. Those of ordinary skill in the art Under the enlightenment of the present invention, without departing from the purpose of the present invention and the scope of protection of the claims, personnel can also make specific changes in many forms, and these all belong to the protection scope of the present invention.

Claims (9)

1. a kind of gravity type bucket foundation with skirtboard, it is characterised in that including steel cylindrical structure, reinforced concrete canopy, Armored concrete changeover portion；

The steel cartridge type inside configuration is disposed with multiple subdivision plates, so that the steel cylindrical structure is constituted with the subdivision plate The sealing subdivision of multiple bottom openings；

The reinforced concrete canopy bottom is connected with the steel cylindrical structure using WELDING STUDS；The reinforced concrete canopy Edge sets the armored concrete skirtboard for upwardly extending, and the armored concrete skirtboard is once poured with the reinforced concrete canopy Build up type；The reinforced concrete canopy corresponds to each sealing subdivision and is disposed with drinking-water pipe；

The armored concrete changeover portion is poured and is connected to the reinforced concrete canopy top.

2. a kind of gravity type bucket foundation with skirtboard according to claim 1, it is characterised in that the steel cartridge type knot A diameter of 10~50m of structure, wall thickness is 10~100mm.

3. a kind of gravity type bucket foundation with skirtboard according to claim 1, it is characterised in that the steel cartridge type knot The sealing subdivision that structure and the subdivision plate are constituted is cellular subdivision structure, including the regular hexagon subdivision at center and uniform It is arranged at six identical side subdivisions around it；The length of side of regular hexagon subdivision and side subdivision is impartial, is the steel cartridge type 0.25 times of diameter of movement.

4. a kind of gravity type bucket foundation with skirtboard according to claim 1, it is characterised in that the height of the subdivision plate Degree is identical with the bucket foundation barrel, and thickness is identical with the bucket foundation barrel.

5. a kind of gravity type bucket foundation with skirtboard according to claim 1, it is characterised in that the armored concrete 3~the 5m of cap diameter with diameter greater than steel cylindrical structure of top cover, the thickness of the reinforced concrete canopy for 0.2~ 0.6m。

6. a kind of gravity type bucket foundation with skirtboard according to claim 1, it is characterised in that the armored concrete The height of skirtboard is 0.5~1.5m, and thickness is 0.2~0.5m.

7. a kind of gravity type bucket foundation with skirtboard according to claim 1, it is characterised in that the armored concrete The height of changeover portion is 5~10 meters, and thickness is 0.1~2m, and top surface diameter is less than or equal to basal diameter, and wall is in arc Concave curved surface, the curvature of curved surface is 1/60~1/10.

8. a kind of gravity type bucket foundation with skirtboard according to claim 1, it is characterised in that the armored concrete Changeover portion is prestressed reinforced concrete construction, and deformed bar is disposed with inside it, and the ratio of reinforcement is not less than 0.3%, its prestress steel The tension stress of muscle is not less than 0.75 times of reinforcement yielding stress.

9. a kind of construction method of gravity type bucket foundation as any one of claim 1-8 with skirtboard, its feature exists In carrying out in accordance with the following steps：

(1) will assemble in the gravity type bucket foundation immigration water of tower and blower fan, its entirety is swum on the water surface；

(2) gravity type bucket foundation transportation by driving support is navigated to specified job location, the sea bed of job location is carried out preliminary smooth；

(3) drinking-water pipe on the reinforced concrete canopy is opened, gravity type bucket foundation is sunk down into sea bed by deadweight；

(4) deadweight is taken out by the drinking-water pipe on the reinforced concrete canopy after sinking to stopping to the steel cartridge type inside configuration Water, is made gravity type bucket foundation be sunk by negative pressure and continues to sink；

(5) after gravity type barrel-shaped foundation sinking is in place, the armored concrete skirtboard and the armored concrete changeover portion it Between throwing ballast stone, total construction finish.