CN218346230U

CN218346230U - Offshore composite foundation

Info

Publication number: CN218346230U
Application number: CN202222636462.5U
Authority: CN
Inventors: 胡中波; 刘欣怡; 李阔; 刚傲; 田德帅; 刘畅博; 史楠
Original assignee: PowerChina Chengdu Engineering Co Ltd
Current assignee: PowerChina Chengdu Engineering Co Ltd
Priority date: 2022-10-08
Filing date: 2022-10-08
Publication date: 2023-01-20
Anticipated expiration: 2032-10-08

Abstract

The utility model discloses a marine composite foundation belongs to the ocean engineering construction field, and the purpose provides a compound foundation structure under water and construction method that bears the weight of dynamic height, construction cycle is short, economic nature is good. The utility model adopts the technical proposal that: offshore composite foundation, including suction bucket, steel-pipe pile and anchor assembly, suction bucket opening is down and back-off in the overburden, the steel-pipe pile is worn to establish by the inner tube of suction bucket, the lower extreme of steel-pipe pile is located the basement rock, the pile bottom of steel-pipe pile sets up the bed course, set up the anchor hole in the bed course, the drilling in bottom in anchor hole for being located the basement rock sets up anchor assembly and anchor in the basement rock, spring and fixed connection cushion are worn to establish by anchor assembly's upper end, form prestressing force anchorage system. The construction method of the offshore composite foundation is used for constructing the offshore composite foundation in the shallow overburden rock seabed sea area. The utility model is used for the design and the construction of marine wind-power electricity basis in shallow overburden rock foundation seabed.

Description

Offshore composite foundation

Technical Field

The utility model belongs to the ocean engineering construction field specifically is a structure of compound basis under sea and water and construction method thereof.

Background

The offshore wind power foundation mainly comprises a single-pile foundation, a pile group high bearing platform foundation, a gravity type foundation, a suction bucket foundation, a multi-foot stand foundation, a jacket foundation and a floating foundation. The single-pile foundation has the characteristics of simple structure, convenience in construction, short period and the like, is a preferred foundation type of offshore wind turbines (with the sea depth of 10-45 m), and accounts for more than 65% of all foundation types.

Part of offshore areas in China are shallow-overburden rock seabed foundations, soft soil on the surface of the seabed is easily liquefied or scoured and damaged under the action of sea waves, and therefore foundation piles need to be embedded into the lower lying rocks. Because the steel pipe pile is easy to encounter that the rock surface is greatly fluctuated and the driving depth of the steel pipe pile such as boulder is limited in the driving process, in order to meet the design requirement of the bearing capacity of the pile foundation, the rock-socketed part needs to be subjected to rotary excavating construction and cast-in-place pile treatment.

Unlike inland infrastructure, offshore wind turbine foundation and superstructures need to bear larger, more complex, and periodic ocean loads. At present, a pile group high bearing platform foundation is often adopted in the sea area under the geological conditions. The high pile group bearing platform foundation is high in manufacturing cost and long in construction period, is influenced by bad weather such as poor construction environment and typhoon, and has huge potential risks in the construction of offshore wind farms. The key technical problem for promoting the development of new energy is to select the offshore wind farm fan foundation with high safety, short construction period and reasonable construction cost.

In summary, the design and construction method of the offshore wind power foundation in the shallow rock seabed sea area still has the improvement part, and the aspects of safety, construction period, cost and the like are optimized. With the continuous development of new energy industry, a reasonable offshore wind power foundation type and a construction method are provided, and the method has important social and economic significance for improving an energy structure.

SUMMERY OF THE UTILITY MODEL

The utility model provides an at first compound basis on sea, the purpose provides one kind and is used for shallow overburden rock seabed sea area, and bears the weight of the compound basis under water that high, construction cycle is short, economic nature is good.

The utility model adopts the technical proposal that: the marine composite foundation comprises a suction barrel, a steel pipe pile and an anchoring piece, wherein the suction barrel comprises an inner barrel and an outer barrel, the inner barrel is connected with the outer barrel through a circular barrel bottom, the central lines of the inner barrel and the outer barrel are superposed and vertically arranged, the opening of the suction barrel faces downwards and is reversely buckled on a covering layer, the steel pipe pile is arranged on the inner side of the inner barrel of the suction barrel in a penetrating mode, a grouting material is filled in a gap between the inner barrel and the steel pipe pile, the lower end of the steel pipe pile is located on a foundation rock, a cushion layer is arranged at the pile bottom of the steel pipe pile and is cast-in-place hydraulic concrete, anchoring holes are reserved or drilled in the cushion layer, the bottom of each anchoring hole is a drilling hole located in the foundation rock, anchoring pieces are arranged in the anchoring holes and the drilling holes, grouting bodies are arranged between the hole and the hole wall of the drilling hole and the anchoring piece, the upper ends of the anchoring pieces are fixedly connected with the upper ends of the anchoring pieces, springs are arranged on the bottom surfaces of the cushion layers and the surfaces of the anchoring pieces respectively, and form a prestress anchoring system.

Further, the method comprises the following steps: the inner cylinder, the outer cylinder and the bottom of the cylinder are all made of steel, and the cylinder openings of the inner cylinder and the outer cylinder are provided with cutting edges.

Specifically, the method comprises the following steps: the height of the inner cylinder is less than or equal to that of the outer cylinder. For example, the height of the outer cylinder is 10 to 15m.

Specifically, the method comprises the following steps: the wall thickness of the steel pipe pile is 30mm, and the outer diameter is 1.9m.

Specifically, the method comprises the following steps: the anchoring piece is a prestressed steel strand or an anchor rod.

Further, the method comprises the following steps: the anchoring holes are in accordance with the diameter of the drilled holes and are arranged vertically.

Further, the method comprises the following steps: the length of the anchoring piece embedded into the drill hole is at least three times of the outer diameter of the steel pipe pile.

Specifically, the method comprises the following steps: the anchoring holes are uniformly arranged on the surface of the cushion layer along the circumferential direction.

The utility model also provides a construction method of marine composite foundation for at shallow overburden rock seabed sea area construction composite foundation structure, including following step:

s1, an opening of a suction barrel faces downwards, then the suction barrel sinks to a covering layer of a seabed, and finally the suction barrel sinks to a preset depth; the suction barrel comprises an inner barrel and an outer barrel, the inner barrel is connected with the outer barrel through a circular barrel bottom, and the central lines of the inner barrel and the outer barrel are overlapped and vertically arranged. For example, the suction bucket sinks to the surface of the cover layer under the action of self-gravity, and then the suction bucket gradually sinks to a predetermined depth under the action of water pressure for pumping out water between the inner cylinder and the outer cylinder.

Further, the method comprises the following steps: the inner cylinder, the outer cylinder and the cylinder bottom are all made of steel parts, and the cylinder openings of the inner cylinder and the outer cylinder are provided with cutting edges.

Further, the method comprises the following steps: the height of the inner cylinder is less than or equal to that of the outer cylinder. For example, the height of the outer cylinder is 10 to 15m.

And S2, driving the steel pipe pile into the inner cylinder, wherein the steel pipe pile penetrates through the covering layer, and the lower end of the steel pipe pile is located on the bedrock. For example, the steel pipe pile has a wall thickness of 30mm and an outer diameter of 1.9m.

And S3, digging out soil bodies in the steel pipe piles, pouring hydraulic concrete in situ at the bottoms of the steel pipe piles to form a cushion layer, reserving or drilling anchoring holes in the cushion layer, and drilling the foundation rock through the anchoring holes.

Further, the method comprises the following steps: the anchoring holes are in the same diameter as the drilled holes and are vertically arranged.

Further, the method comprises the following steps: the anchoring holes are uniformly arranged on the surface of the cushion layer along the circumferential direction.

And S4, inserting the anchoring piece into the drilled hole through the anchoring hole, grouting and sealing the anchoring hole until grouting pressure reaches the limit or grouting amount reaches the design value, and forming an anchoring body by grouting between the anchoring hole and the hole wall of the drilled hole and the anchoring piece.

And S5, sleeving a spring into the upper end of the anchoring part, fixedly connecting the upper end of the anchoring part with the cushion block to compress the spring, and enabling the two ends of the spring to act on the bottom surface of the cushion block and the surface of the cushion layer respectively to form a prestressed anchoring system.

And S6, injecting grouting materials into the gap between the inner tube and the steel pipe pile.

The utility model has the advantages that: the utility model is suitable for a design and construction of offshore wind-power basis in shallow overburden rock foundation seabed. The offshore composite foundation and the construction method thereof can ensure the capability of the foundation for resisting vertical, horizontal and overturning loads, reduce the bearing capacity weakened by the erosion damage of sea waves to soil bodies, avoid the adoption of pile group foundations, reduce materials, save cost and shorten the construction period. The vertical bearing capacity of the composite foundation can be improved by the aid of the friction force of the steel pipe pile, the anchoring piece and the suction barrel of the offshore composite foundation and the outer wall of the steel pipe pile. The suction barrel is reversely buckled and embedded into the covering layer, a grouting material is filled in a gap between the inner barrel of the suction barrel and the steel pipe pile, and the inner barrel and the steel pipe pile form an integral structure, so that the horizontal bearing capacity and the anti-overturning capacity of the composite foundation can be improved. The spring at the top of the anchoring piece can effectively reduce the vertical load generated after the upper structure is installed, so that the prestress loss is caused.

The openings of the inner cylinder and the outer cylinder are provided with cutting edges, so that the suction bucket can sink into the covering layer of the seabed. The height of the inner cylinder is less than or equal to that of the outer cylinder, which is beneficial to the construction of the suction barrel and saves materials.

Drawings

Fig. 1 is a schematic structural diagram of the marine composite foundation of the present invention.

Fig. 2 is a schematic horizontal cross-sectional view of the steel pipe pile of fig. 1 at the cushion layer.

FIG. 3 is a schematic elevational view of the prestressed anchorage system of FIG. 1.

Reference numerals are as follows: the device comprises a suction bucket 1, a steel pipe pile 2, an anchoring piece 3, a covering layer 4, bedrock 5, a cushion layer 6, an anchoring body 7, a cushion block 8, a spring 9, seawater 10 and a sea surface 11.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings.

Referring to fig. 1, sea water 10 is below the sea surface 11 of the shallow overburden rock seabed sea area, the seabed is the overburden 4, and bedrock 5 is at the bottom of the overburden 4. The utility model provides a marine composite foundation and construction method thereof, composite foundation can be used to the basis of offshore wind turbine.

Referring to fig. 1 to 3, the first subject of the present invention is: the offshore composite foundation comprises a suction barrel 1, a steel pipe pile 2 and an anchoring piece 3, wherein the suction barrel 1 comprises an inner barrel and an outer barrel, the inner barrel and the outer barrel are connected through an annular barrel bottom, the central lines of the inner barrel and the outer barrel are superposed, and the inner barrel, the outer barrel and the barrel bottom are all made of steel and are connected to form an integral structure. The opening of the suction barrel 1 faces downwards and is reversely buckled on the covering layer 4, and the central lines of the inner barrel and the outer barrel are vertically arranged. Since the suction bucket 1 is embedded in the covering layer 4, in order to facilitate the suction bucket 1 to sink into the covering layer of the seabed, the mouths of the inner cylinder and the outer cylinder are provided with cutting edges, such as beveled cutting edges. Because the suction barrel 1 is constructed in an inverted buckle mode, the height of the inner barrel is smaller than or equal to that of the outer barrel in order to avoid the inner barrel from obstructing the construction. For example, in the embodiment shown in FIG. 1, the height of the inner barrel is less than the height of the outer barrel. The specific parameters of the inner cylinder and the outer cylinder, such as diameter, height, thickness and the like, are determined by calculation according to geological conditions, upper load and the like, and the height of the outer cylinder is 10-15 m in general.

Steel pipe pile 2 is worn to establish in the inner tube inboard of suction bucket 1, clearance fit between suction bucket 1 and the steel pipe pile 2 to guarantee that steel pipe pile 2 can squeeze into smoothly. The lower end of the steel pipe pile 2 is located on the bedrock 5, and the bedrock 5 supports the steel pipe pile 2. The clearance between inner tube and steel-pipe pile 2 fills grouting material, and grouting material both can avoid steel-pipe pile 2 to appear rocking after solidifying, still makes inner tube and steel-pipe pile 2 be connected fixedly, improves the ability of resisting vertical, level, overturning load. The diameter of the steel pipe pile 2 is large, and a construction space corresponding to land can be formed inside the steel pipe pile 2. For example, the steel-pipe pile 2 has a wall thickness of 30mm and an outer diameter of 1.9m.

The bottom of the steel pipe pile 2 is provided with a cushion layer 6, and the bottom of the cushion layer 6 is bedrock 5. The cushion layer 6 is cast-in-situ hydraulic concrete, and vertically arranged anchoring holes are reserved or drilled in the cushion layer 6. The anchor member 3 passes through the anchor hole of the cushion layer 6 and is embedded in the bedrock 5.

According to the stress of the steel pipe pile 2, the anchoring holes are uniformly distributed on the surface of the cushion layer 6 along the circumferential direction, the anchoring holes can be in a circle or multiple circles, for example, see fig. 2, the anchoring holes are in a circle. The anchoring piece 3 adopts a prestress structure, and the anchoring piece 3 can be a prestress steel strand or an anchor rod. Referring to fig. 3, the bottom of the anchoring hole is a borehole in the bedrock 5, the anchoring hole and the borehole are preferably vertically arranged, and the diameter of the anchoring hole is consistent with that of the borehole, so that construction is facilitated. Anchoring pieces 3 are arranged in the anchoring holes and the drilled holes, and anchoring bodies 7 formed by grouting are arranged between the anchoring pieces 3 and the hole walls of the anchoring holes and the drilled holes, so that the anchoring pieces 3 are firmly combined with bedrocks 5. In order to secure the bonding strength of the anchor member 3 to the bedrock 5, the length of the anchor member 3 inserted into the drill hole is at least three times the outer diameter of the steel pipe pile 2. In order to reduce the prestress loss caused by the vertical load generated after the superstructure is installed, the upper end of the anchoring piece 3 is fixedly connected with a cushion block 8, the anchoring piece 3 penetrates through a spring 9 at the lower part of the cushion block 8, and two ends of the spring 9 respectively act on the bottom surface of the cushion block 8 and the surface of the cushion layer 6 to form a prestress anchoring system.

The utility model provides a second theme is marine composite foundation's construction method, is the construction method of above-mentioned first theme for at shallow overburden 4 rock seabed sea area construction composite foundation structure, including following step.

S1, the opening of the suction bucket 1 is downward, and then the suction bucket is sunk to the covering layer 4 of the seabed and finally sunk to a preset depth. The suction bucket 1 comprises an inner barrel and an outer barrel which are connected through a circular barrel bottom, and the structural characteristics of the suction bucket 1 refer to the description of the suction bucket 1 in the first subject. The suction barrel 1 sinks to the surface of the covering layer 4 under the action of self-gravity, and then the suction barrel 1 sinks to a preset depth gradually under the action of water pressure for pumping water between the inner barrel and the outer barrel. In the process of sinking the suction barrel 1, the central line of the suction barrel 1 is always in a vertical state and sinks by adjusting the pressure difference of the suction barrel 1.

And S2, driving the steel pipe pile 2 into the inner cylinder, wherein the steel pipe pile 2 penetrates through the covering layer 4 until the lower end of the steel pipe pile 2 is located on the bedrock 5. For structural features of the steel pipe pile 2, reference is made to the description of the steel pipe pile 2 given above in the first subject.

And S3, digging out soil bodies inside the steel pipe pile 2, pouring hydraulic concrete in situ at the bottom of the steel pipe pile 2 to form a cushion layer 6, reserving anchoring holes in the cushion layer 6 or drilling the anchoring holes in the cushion layer 6, and then drilling the foundation rock 5 through the anchoring holes. According to the stress of the steel pipe pile 2, the anchoring holes are uniformly arranged on the surface of the cushion layer 6 along the circumferential direction, the anchoring holes can be arranged in a circle or multiple circles, for example, referring to fig. 1, a circle of anchoring holes are reserved in the cushion layer 6. In order to facilitate drilling construction, the anchoring holes are vertical and consistent with the diameter of the drilled holes. The depth of the drilled hole reaches the designed depth of the anchoring member 3 embedded in the bedrock 5, for example, the depth of the drilled hole is at least three times the outer diameter of the steel pipe pile 2, that is, the length of the anchoring member 3 embedded in the drilled hole is at least three times the outer diameter of the steel pipe pile 2.

And S4, inserting the anchoring piece 3 into the drilled hole through the anchoring hole, and grouting and sealing the anchoring hole until grouting pressure reaches the limit or grouting amount reaches the designed value, so that slurry is completely filled in the anchoring hole and the drilled hole. An anchoring body 7 formed by grouting is arranged between the anchoring hole and the hole wall of the drill hole and the anchoring piece 3, so that the anchoring piece 3 is firmly combined with the bedrock 5. The anchoring piece 3 adopts a prestress structure and can be a prestress steel strand or an anchor rod.

S5, sleeving a spring 9 into the upper end of the anchoring part 3, fixedly connecting the upper end of the anchoring part 3 with a cushion block 8, compressing the spring 9, and enabling two ends of the spring 9 to act on the bottom surface of the cushion block 8 and the surface of the cushion layer 6 respectively to form a prestressed anchoring system. The spring 9 is used for reducing the vertical load generated after the upper structure is installed to cause prestress loss, and the cushion block 8 is used for balancing the compression counter force of the spring 9.

S6, grouting materials are injected into the gap between the inner cylinder and the steel pipe pile 2, after the grouting materials are solidified, the inner cylinder and the steel pipe pile 2 form an integral structure, the steel pipe pile 2 cannot shake under the action of horizontal load relative to the suction barrel 1, and the horizontal bearing capacity and the anti-overturning capacity of the composite foundation can be improved. The grouting material is used for fixedly connecting the inner cylinder with the steel pipe pile 2, so that the vertical bearing capacity of the composite foundation is improved.

Claims

1. Marine compound basis, its characterized in that: including suction bucket (1), steel-pipe pile (2) and anchor assembly (3), suction bucket (1) includes inner tube and urceolus, link to each other through the annular barrel head of circle between inner tube and the urceolus, the central line coincidence and vertical arrangement of inner tube and urceolus, suction bucket (1) opening is down and back-off in overburden (4), steel-pipe pile (2) are worn to establish to the inner tube inboard of suction bucket (1), the gap between inner tube and steel-pipe pile (2) fills grouting material, the lower extreme of steel-pipe pile (2) is located in basement rock (5), the pile head of steel-pipe pile (2) sets up bed course (6), bed course (6) are cast-in-place hydraulic concrete, reserve or bore the anchor hole of establishing vertical arrangement in bed course (6), the bottom in anchor hole is for being located the drilling in basement rock (5), set up anchor assembly (3) in anchor hole and the drilling, anchor body (7) for the mud jacking formation between the pore wall of anchor hole and anchor assembly (3) of anchor hole and the anchor assembly (3), the upper end fixed connection bed course (8) of anchor assembly (3), anchor assembly (3) are worn to establish cushion (9) and are acted on the bottom surface of spring (9) and form the anchor assembly (8) respectively with the anchor assembly (8).

2. An offshore composite foundation as set forth in claim 1 wherein: the inner cylinder, the outer cylinder and the cylinder bottom are all made of steel parts, and the cylinder openings of the inner cylinder and the outer cylinder are provided with cutting edges.

3. An offshore composite foundation as claimed in claim 1 wherein: the height of the inner cylinder is less than or equal to that of the outer cylinder.

4. An offshore composite foundation as claimed in claim 3 wherein: the height of the outer cylinder is 10-15 m.

5. An offshore composite foundation as set forth in claim 1 wherein: the wall thickness of the steel pipe pile (2) is 30mm, and the outer diameter is 1.9m.

6. An offshore composite foundation as claimed in any one of claims 1 to 5 wherein: the anchoring piece (3) is a prestressed steel strand or an anchor rod.

7. An offshore composite foundation as claimed in any one of claims 1 to 5 wherein: the anchoring holes are in accordance with the diameter of the drilled holes and are arranged vertically.

8. An offshore composite foundation as claimed in any one of claims 1 to 5 wherein: the length of the anchoring piece (3) embedded into the drill hole is at least three times of the outer diameter of the steel pipe pile (2).

9. An offshore composite foundation as claimed in any one of claims 1 to 5 wherein: the anchoring holes are uniformly arranged on the surface of the cushion layer (6) along the circumferential direction.