CN106906839A - A kind of combined 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 combined 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; the top of the steel cylindrical structure The outer edge of the cover expands out of the steel tubular structure and is welded with a steel skirt, and the edge of the reinforced concrete roof is provided with a reinforced concrete skirt; the lower part of the reinforced concrete roof is connected to the steel tubular structure with shear nails, and the upper part is connected to the The concrete transition section is poured and connected; during construction, the bottom of the steel skirt plate enters the seabed through self-weight sinking and negative pressure sinking in sequence, and then pumps water through the suction pipe inside the steel skirt plate to increase the sinking force; after sinking in place, the Ballast stones are thrown between the reinforced concrete apron and the reinforced concrete transition section. The invention has the advantages of simple structure, convenient construction, low cost, self-floating towage and sinking, and the increase of the skirt plate can increase the anti-overturning and anti-scouring ability of the foundation in normal use, and effectively improve the sinking force of the foundation.

Description

A combined tubular foundation with aprons and its construction method

technical field

The invention belongs to the field of offshore wind power foundations, and in particular relates to a combined 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 the offshore wind power foundation structure, the present invention provides a combined cylindrical foundation with apron and its construction method. The increase of the skirt plate can increase the anti-overturning and anti-scouring capabilities of the foundation during normal use, and effectively improve the sinking force of the foundation, while reducing the development of soil plugs inside the steel cylindrical foundation.

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

A combined tubular foundation with aprons, including a steel tubular structure, a reinforced concrete roof, and a reinforced concrete transition section;

The outer edge of the top cover of the steel cylindrical structure expands out of the steel cylindrical structure, and the outer edge of the top cover of the steel cylindrical structure is welded with a steel skirt plate extending downward from the top cover; 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 molding; the reinforced concrete roof is arranged with a plurality of suction pipes, including the suction pipes corresponding to each sealed sub-compartment and corresponding to the pipe between the steel skirt plate and the steel cylindrical structure wall. Suction pipes uniformly distributed around the ring;

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

Preferably, the diameter of the steel cylindrical structure is 10-50m, and the wall thickness is 10-100mm; the diameter of the top cover of the steel cylindrical structure is 1.2-2 times the diameter of the bottom annular cylinder wall.

Preferably, the height of the steel skirt plate is 0.1-0.5 times the height of the main cylinder wall of the steel cylindrical structure.

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 the same as that of the steel cylindrical structure, which is 10-50m; the thickness 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 above-mentioned construction method of the combined cylindrical foundation with the skirt plate is carried out according to the following steps:

(1) Move the combined 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 combined cylindrical foundation to the designated construction site, and initially leveling the seabed at the construction site;

(3) Open all the pumping pipes on the reinforced concrete roof, so that the combined cylindrical foundation sinks to the seabed by its own weight;

(4) After the self-weight sinking stops, the pumping pipe corresponding to the steel cylindrical structure is pumped inside the steel cylindrical structure, so that the combined cylindrical foundation continues to sink through negative pressure sinking;

(5) When the negative pressure sinks to the bottom of the steel skirt plate and enters the seabed, pump water through the pumping pipe corresponding to the pipe between the steel skirt plate and the wall of the steel tubular structure, increasing The sinking force of the combined barrel foundation;

(6) After the combined 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 combined cylindrical foundation with apron and its construction method of the present invention has a simple and compact foundation structure, convenient and fast construction, and the addition of the lower steel apron effectively improves the sinking force of the foundation and can reduce the height of the soil plug inside the foundation The development of the upper reinforced concrete apron, after throwing ballast stones to its interior, can also effectively improve the anti-overturning and anti-scouring capabilities of the foundation. Large-scale equipment is required, and it has the characteristics of low cost and high construction efficiency.

Description of drawings

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

Fig. 2 is the bottom view of the combined cylindrical foundation with apron provided by the present invention;

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

Fig. 4 is a front view of the combined cylindrical foundation with apron provided by the present invention after construction is completed.

In the figure: 1. Reinforced concrete transition section; 2. Ballast stones; 3. Reinforced concrete apron; 4. Reinforced concrete roof; 5. Steel apron; 6. Suction pipe; 7. Steel tubular structure ; 8, subdivision board.

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 Figures 1 to 3, this embodiment provides a combined tubular foundation with aprons, which mainly consists of a reinforced concrete transition section 1, a reinforced concrete top cover 4, and a steel tubular structure 7.

The steel cylindrical structure 7 has a diameter of 10-50m and a wall thickness of 10-100mm. The outer edge of the top cover of the steel cylindrical structure 7 extends beyond the bottom annular wall, and the diameter of the top cover of the steel cylindrical structure 4 is 1.2 to 2 times the diameter of the bottom annular wall. The outer edge of the top cover of the steel cylindrical structure 4 is welded with a steel skirt plate 3 extending downward from the top cover. The height of the steel skirt plate 3 is 0.1 to 0.5 times the height of the main tube, and the wall thickness is the same The cylinder wall of 7 is identical.

In order to facilitate foundation sinking and leveling, a plurality of subdivision plates 8 are arranged inside the steel cylindrical structure 7, so that the steel cylindrical structure 7 and the subdivision plates 8 form a plurality of sealed subdivisions with bottom openings. Preferably, the steel cylindrical structure 7 and the subdivision plate 8 form a honeycomb subdivision structure, including a regular hexagonal subdivision in the center and six identical side subdivisions evenly 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 7, 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 8 is welded and fixed to the inner top wall of the steel tubular structure 7. The height of the subdivision plate 8 is the same as the height of the main cylinder of the steel tubular structure 7, and the thickness is the same as the wall of the steel tubular structure 7.

The reinforced concrete roof 4 has a diameter of 10-50 m, which is the same as 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 7 by using shear nails. There are thirteen suction pipes 6 arranged on the reinforced concrete roof 4, one of which corresponds to the seven sub-compartments of the steel tubular structure 4, and one corresponding to the steel tubular structure 7 wall and the steel skirt 3 There are six evenly distributed annular parts. The diameter of the suction pipe 5 is 20-200 mm, corresponding to the steel cylindrical structure 4, the top of the suction pipe 5 passes through the reinforced concrete roof 4, and the bottom extends to the inside of the steel cylindrical structure 7, and corresponds to the steel cylindrical structure 4 The top of the suction pipe 5 between the cylinder wall of the structure 7 and the steel skirt 3 is higher than the reinforced concrete skirt 3 , and the bottom extends to the inside of the steel cylinder 7 .

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 combined tubular foundation with aprons, which is carried out according to the following steps:

a. The prefabricated steel cylindrical structure 7 on land, the subdivision plate 8 is welded inside the steel cylindrical structure 7, and the steel skirt plate 5 is welded on the outer edge of the top cover of the steel cylindrical structure 7;

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 cylindrical structure 7, and arrange the reinforcement, pour the reinforced concrete roof 2 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 7 with shear nails, install the water pipe 6 on the reinforced concrete top cover 4 at the same time, and combine the reinforced concrete top cover 4 and the steel cylindrical structure 7 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 combined cylindrical foundation with the assembled tower and fan into the water, and the self-floating ability of the combined cylindrical foundation makes it float on the water as a whole;

g. Use the tugboat to tow the combined cylindrical foundation to the designated construction site, and at the same time make preliminary leveling of the seabed at the construction site;

h. Open all the pumping pipes 6 on the reinforced concrete top cover 4, so that the combined cylindrical foundation sinks to the seabed by its own weight; after the self-weight sinking stops, the steel pipes 6 corresponding to the steel cylindrical structure 7 are drawn out. Excess water in the cylindrical structure 7 is extracted by means of the water body to realize the negative pressure in the steel cylindrical structure 7, that is, the negative pressure sinking process;

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

i. When the negative pressure sinks to the bottom of the steel skirt 5 and enters the seabed, pump water through the pumping pipe 5 corresponding to the steel tubular structure 7 wall and the steel skirt 3, and add a combined barrel The sinking force of the type foundation;

j. After the combined 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 (10)

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

The top cover outer rim of the steel cylindrical structure is expanded in outside the steel cylindrical structure, the top cover of the steel cylindrical structure Edge is welded with the steel skirtboard extended downwardly by top cover；The steel cartridge type inside configuration is disposed with multiple subdivision plates, so that institute State the sealing subdivision that steel cylindrical structure constitutes multiple bottom openings with the subdivision plate；

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 is disposed with multiple drinking-water pipes, including drinking-water pipe corresponding to each sealing subdivision and right The uniform drinking-water pipe of annular section between steel skirtboard described in Ying Yu and the steel cylindrical structure barrel；

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

2. a kind of combined 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；The cap diameter of the steel cylindrical structure is that base circle barrel is straight 1.2~2 times of footpath.

3. a kind of combined type bucket foundation with skirtboard according to claim 1, it is characterised in that the steel skirtboard Highly for 0.1~0.5 times of the steel cylindrical structure main cylinder barrel highly.

4. a kind of combined 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.

5. a kind of combined 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.

6. a kind of combined type bucket foundation with skirtboard according to claim 1, it is characterised in that the armored concrete The diameter of top cover is identical with the cap diameter of steel cylindrical structure, is 10~50m；Thickness is 0.2~0.6m.

7. a kind of combined 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.

8. a kind of combined 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.

9. a kind of combined 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.

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

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

(2) combined 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) all drinking-water pipes on the reinforced concrete canopy are opened, combined type bucket foundation is sunk down into sea by deadweight Bed；

(4) by the drinking-water pipe corresponding to the steel cylindrical structure to the steel cartridge type inside configuration after deadweight sinks to stopping Draw water, combined type bucket foundation is sunk by negative pressure and continue to sink；

(5) when negative pressure sinks down into the steel skirtboard bottom into sea bed, then by corresponding to the steel skirtboard and the steel Drinking-water pipe auxiliary between cylindrical structure barrel processed is drawn water, and increases the down force of combined type bucket foundation；

(6) after combined 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.