CN111549813A - Deep-sea wind power generation jacket-type monopile composite structure and its construction method - Google Patents

Abstract

The invention relates to a deep sea wind power generation jacket type single-pile composite structure and a construction method thereof. The technical scheme of the invention is as follows: the utility model provides a deep sea wind power generation jacket formula single pile composite construction which characterized in that: the large-diameter steel pipe, the transition section, the jacket main body structure and the steel pipe pile are arranged; wherein the upper end of the large-diameter steel pipe is positioned above the top elevation of the wave action range of the service engineering field of the single-pile composite structure, and the lower end of the large-diameter steel pipe is positioned below the bottom elevation of the wave action range; the lower end of the large-diameter steel pipe is connected with a jacket main structure below the large-diameter steel pipe through a transition section, the lower end of the jacket main structure is connected with a plurality of steel sleeves, the jacket main structure is sleeved on a steel pipe pile through the steel sleeves, the steel pipe pile sinking pile is fixed on a seabed, and high-strength grouting materials are poured between the steel sleeves and the steel pipe pile to be connected. The invention is suitable for the offshore wind power generation industry, in particular to a foundation structure which is used in an engineering field with the water depth of more than 30 meters.

Description

Deep-sea wind power generation jacket-type monopile composite structure and its construction method

technical field

The invention relates to a deep-sea wind power generation jacket-type single-pile composite structure and a construction method thereof. It is suitable for the offshore wind power generation industry, especially for the infrastructure in engineering fields with a water depth of more than 30 meters.

Background technique

In the context of the increasingly severe situation of traditional fossil energy, countries around the world have turned their attention to wind energy, a clean energy source, of which offshore wind energy is particularly important. China's grid-connected offshore wind power capacity ranks third in the world after the United Kingdom and Germany. The development of offshore wind energy resources has gradually moved from intertidal and subtidal mudflat wind farms to offshore wind farms and deep-sea wind farms. In the process of offshore and deep-sea wind energy utilization, the jacket infrastructure is widely used because of its advantages of saving steel, low manufacturing difficulty, and mature construction technology.

The operating platform of the jacket infrastructure of the traditional offshore oil industry is located above the sea level, and the pile legs extend from the working point elevation to the seabed with a certain slope. The structure has good economy in the range of water depth of 30 meters, but with the further increase of water depth, the projected area of the jacket structure on the seabed surface continues to increase, and the amount of steel used for the entire structure continues to increase. As a result, if the offshore wind turbine adopts the traditional jacket structure of the offshore oil industry, the sea area occupied by the foundation will increase, and the amount of steel used for the foundation structure will further increase. The monopile foundation has the advantages of simple structure, clear force, and no complicated T, K, Y nodes. However, with the increase of water depth, in order to maintain the overall stiffness, the pile diameter and wall thickness of the single pile foundation will increase rapidly, and the engineering quantity and foundation cost will increase rapidly.

In the marine environment with harsh service conditions, the foundation structure of offshore wind turbines has been subjected to the alternating action of marine environmental loads during the service period, and the cyclic action of the loads generated by the operation of the wind turbine on the foundation structure has resulted in fatigue loads that have become the foundation of offshore wind turbines. The main control load of the structure. The traditional jacket foundation structure has many chords, diagonal braces and nodes in the range of wave action. The fatigue damage of the foundation structure under the action of wave load becomes an important challenge in the design of the foundation structure. At the same time, the traditional jacket foundation structure is subjected to large wave loads, resulting in a corresponding increase in the lateral and vertical bearing capacity of the pile foundation, which directly makes the pile diameter of the traditional jacket foundation structure larger and the wall thickness thicker. , the pile length is longer.

To sum up, in order to solve the above problems, it is urgent to propose a composite foundation that can make full use of the advantages of the jacket and the monopile foundation and overcome the problems existing in the jacket and the monopile foundation.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a deep-sea wind power generation jacket-type single-pile composite structure and a construction method for the above-mentioned problems.

The technical scheme adopted in the present invention is: a deep-sea wind power generation jacket-type monopile composite structure, which is characterized in that it has a large-diameter steel pipe, a transition section, a jacket main structure and a steel pipe pile;

The upper end of the large-diameter steel pipe is located above the top elevation of the wave action range of the single-pile composite structure service engineering site, and the lower end of the large-diameter steel pipe is located below the bottom elevation of the wave action range;

The lower end of the large-diameter steel pipe is connected to the main structure of the jacket below it through the transition section. The lower end of the main structure of the jacket is connected with a number of steel casings. The main structure of the jacket is sleeved on the steel pipe pile through the steel casing. The pile driving pile is fixed on the seabed, and the steel casing and the steel pipe pile are connected by pouring high-strength grouting material.

The transition section has a plurality of transition steel pipes evenly distributed around the large-diameter steel pipe, one end of the transition steel pipe is connected to the wall of the large-diameter steel pipe, and the other end is connected obliquely downward to the top of the main structure of the jacket.

The lower ends of the adjacent transition steel pipes are connected by diagonal braces.

The main structure of the jacket has a number of main leg columns evenly distributed around the large-diameter steel pipe, adjacent main leg columns are connected by a number of X-shaped diagonal braces, and the main leg columns are connected to the large diameter column from top to bottom. The spacing between the axes of the steel pipes increases gradually.

The lower end of the main leg column is connected to one or more of the steel sleeves vertically arranged around the main leg column through a connecting piece.

A construction method for the deep-sea wind power generation jacket-type monopile composite structure, characterized in that:

First, carry out the pile driving operation of the steel pipe pile;

After the steel pipe pile is driven, its positioning is measured. On the premise that the pile driving accuracy meets the requirements for the next installation of the jacket main structure, the overall structure consisting of the jacket main structure, transition section and large-diameter steel pipe is hoisted to the steel pipe described below. The corresponding position of the pipe pile;

The leveling operation is carried out during the installation of the overall structure;

After the overall structure is lowered and leveled, the steel casing is correspondingly fitted on the steel pipe pile, and high-strength grouting material is poured between the steel pipe pile and the steel casing to seal.

The pile driving operation of the steel pipe pile adopts a pile driving auxiliary positioning mechanism;

The pile driving auxiliary positioning mechanism has a number of positioning auxiliary casing sets corresponding to the steel pipe piles to be constructed by the pile driving. The positioning auxiliary casing sets are all installed and fixed on the positioning auxiliary brackets. There are two positioning auxiliary casings arranged coaxially up and down, and the inner diameter of the positioning auxiliary casing is slightly larger than the outer diameter of the steel pipe pile.

The beneficial effects of the present invention are as follows: the present invention is formed by combining large-diameter steel pipes with the main structure of the jacket, which reduces the projected area of the structure on the seabed surface, reduces the area of sea used, reduces the cost of applying for sea use, and is beneficial to marine environmental protection.

The invention reduces the number of nodes of the basic structure, reduces the welding workload, and adopts large-diameter steel pipes to pass through the wave action range, and the transition section structure is located below the wave action range of the offshore wind turbine service sea area, which significantly reduces the wave load on the foundation structure. The fatigue damage of the joints is increased, and the fatigue life of the structure is improved.

The invention reduces the overall steel consumption, reduces the investment of the basic structure, and has more obvious economic advantages when the water depth of the jacket foundation service engineering field exceeds 30 meters.

The invention adopts a group pile structure, and can avoid rock-socketed construction for shallow overburden engineering sites, improve the efficiency of offshore construction operations, and speed up the construction progress of offshore wind farms.

Description of drawings

FIG. 1 is a schematic structural diagram of the prior art.

FIG. 2 is a schematic structural diagram of an embodiment.

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2 .

FIG. 4 is a top view of the pile driving auxiliary positioning mechanism in the embodiment.

Fig. 5 is a side view of the pile driving auxiliary positioning mechanism in the embodiment.

1. Large diameter steel pipe; 2. Transition steel pipe; 3. Diagonal bracing; 4. Main leg column; 5. X-shaped diagonal bracing; 6. Steel casing; 7. Connecting piece; 8. Steel pipe pile; 9. Positioning aid casing; 10. Positioning auxiliary bracket.

Detailed ways

This embodiment is a deep-sea wind power generation jacket-type single-pile composite structure, which has a large-diameter steel pipe, a transition section, a jacket main structure and a steel pipe pile. The large-diameter steel pipe is connected to the seabed through the transition section and the jacket main structure. Steel pipe piles below the surface.

In this example, the size of the large-diameter steel pipe is 5.5m to 7m, and the optimized size can be designed according to the flange diameter of the tower bottom section set by the wind turbine manufacturer. The length of the large-diameter steel pipe is greater than the difference between the bottom elevation of the wave action range and the top elevation of the foundation in the service engineering field of the single-pile composite structure. Above the top elevation of the wave action range, the lower end of the large-diameter steel pipe is below the bottom elevation of the wave action range to ensure that the transition section is below the wave action range of the engineering site.

In this embodiment, the main structure of the jacket has 4 main legs evenly distributed around the lower part of the large-diameter steel pipe. The distance between the main leg and the axis of the large-diameter steel pipe increases gradually from top to bottom. The columns are connected by two X-shaped diagonal braces up and down.

In this embodiment, the transition section includes four transition steel pipes around the large-diameter steel pipes arranged in a one-to-one correspondence with the main leg columns on the main body structure of the jacket below, and a section of equal-diameter steel pipes connected to the bottom end of the large-diameter steel pipes. The transition section is inclined One end of the brace is connected to the pipe wall of the steel pipe with the same diameter as the large-diameter steel pipe, and the other end is connected obliquely downward to the top of the corresponding main leg column in the main structure of the jacket. The lower ends of the adjacent transition steel pipes are connected by horizontal braces.

In this example, the lower end of the main leg column is connected with two steel casings through the connecting piece. The steel casing is arranged vertically and is located around the main leg column. The inner diameter of the steel casing is slightly larger than the diameter of the steel pipe pile. A radially arranged vertical connecting plate connecting the steel sleeve and the main leg column, and a number of horizontally arranged horizontal connecting plates connecting the connecting steel sleeve and the main leg column.

In this embodiment, the main structure of the jacket is sheathed on the steel pipe pile that is fixed on the seabed through the steel casing, and the outer surface of the steel pipe pile and the inner surface of the steel casing are connected and fixed by pouring high-strength grouting material within the scope of the socketed section. .

With the increase of the single unit capacity of the offshore wind turbine, the load of the wind turbine increases, and the number of steel casings on the steel pipe pile and the main leg column can be increased according to the increase of the wind turbine load. In the engineering site with shallow overburden, if the bearing capacity of the pile foundation meets the requirements, the length of the steel pipe pile can be reduced by increasing the number of steel pipe piles and steel casings, thereby avoiding rock-socketed construction operations.

After designing the number of steel pipe piles, the number of X-shaped diagonal braces on the main structure of the jacket and the diameter of the large-diameter steel pipe according to the characteristics of the offshore wind turbine, the marine environmental conditions of the service site, and the engineering geological conditions, the steel pipe piles will be installed in the construction base. The inner coil, welding, sandblasting, and painting are completed. The main structure of the jacket, the transition section, the large-diameter steel pipe, and the steel casing are processed and formed separately, and the final assembly is completed in the construction base to form an overall structure.

The construction method of this embodiment is as follows:

During offshore construction, the pile driving operation of steel pipe piles is carried out first, and the pile driving auxiliary positioning mechanism is used for auxiliary positioning in the pile driving construction;

After the steel pipe pile is driven, its positioning is measured. On the premise that the pile driving accuracy can meet the requirements of the next installation of the jacket main structure, the overall structure consisting of the jacket main structure, transition section and large-diameter steel pipe is hoisted to its upper steel. The corresponding position of the casing and the steel pipe pile on the seabed;

The leveling operation is continuously carried out during the whole structure lowering and installation process;

After the jacket-type single-pile composite foundation structure is lowered and leveled, the high-strength grouting material is filled between the steel pipe pile and the steel casing to seal, and the grouting process is the same as the ordinary underwater grouting process;

The subsequent offshore installation of towers and wind turbines is consistent with the traditional offshore installation of towers and wind turbines.

In this implementation, the auxiliary positioning mechanism for pile driving has positioning auxiliary casing sets corresponding to the steel pipe piles to be constructed by driving the piles. The auxiliary positioning sleeve sets are all installed and fixed on the auxiliary positioning brackets. Two positioning auxiliary casings arranged coaxially, the inner diameter of the positioning auxiliary casing is slightly larger than the outer diameter of the steel pipe pile.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, and substitutions can be made in these embodiments without departing from the principle and spirit of the invention and modifications, the scope of the present invention is defined by the appended claims and their equivalents.

Claims (7)

1. The utility model provides a deep sea wind power generation jacket formula single pile composite construction which characterized in that: the large-diameter steel pipe, the transition section, the jacket main body structure and the steel pipe pile are arranged;

wherein the upper end of the large-diameter steel pipe is positioned above the top elevation of the wave action range of the service engineering field of the single-pile composite structure, and the lower end of the large-diameter steel pipe is positioned below the bottom elevation of the wave action range;

the lower end of the large-diameter steel pipe is connected with a jacket main structure below the large-diameter steel pipe through a transition section, the lower end of the jacket main structure is connected with a plurality of steel sleeves, the jacket main structure is sleeved on a steel pipe pile through the steel sleeves, the steel pipe pile sinking pile is fixed on a seabed, and high-strength grouting materials are poured between the steel sleeves and the steel pipe pile to be connected.

2. The deep-sea wind power generation jacket type mono-pile composite structure according to claim 1, wherein: the transition section is provided with a plurality of transition steel pipes which are uniformly distributed on the periphery of the large-diameter steel pipe, one end of each transition steel pipe is connected to the pipe wall of the large-diameter steel pipe, and the other end of each transition steel pipe is obliquely downwards connected to the top of the main structure of the jacket.

3. The deep sea wind power generation jacket type single pile composite structure according to claim 2, characterized in that: the lower ends of the adjacent transition steel pipes are connected through a horizontal support.

4. The deep-sea wind power generation jacket type mono-pile composite structure according to claim 1, wherein: the jacket main structure is provided with a plurality of main leg columns which are uniformly distributed on the periphery of the large-diameter steel pipe, adjacent main leg columns are connected through a plurality of X-shaped inclined struts, and the distance between each main leg column and the axis of the large-diameter steel pipe is gradually increased from top to bottom.

5. The deep-sea wind power generation jacket-type single-pile composite structure according to claim 4, wherein: the lower end of the main leg column is connected with one or more steel sleeves which are vertically arranged at the periphery of the main leg column through a connecting piece.

6. A construction method of the deep sea wind power generation jacket type single pile composite structure according to any one of claims 1 to 5, characterized by comprising the following steps:

firstly, pile sinking operation of the steel pipe pile is carried out;

measuring the positioning of the steel pipe pile after the pile sinking of the steel pipe pile is finished, and hoisting an integral structure consisting of a jacket main body structure, a transition section and a large-diameter steel pipe to a position corresponding to the steel pipe pile below on the premise that the pile sinking precision meets the requirement of installing the jacket main body structure in the next step;

leveling operation is carried out in the lowering and installation process of the integral structure;

after the lowering of the integral structure is finished and the leveling is finished, the steel sleeve is correspondingly sleeved on the steel pipe pile, and high-strength grouting material is poured between the steel pipe pile and the steel sleeve to block.

7. The construction method according to claim 6, wherein: pile sinking operation of the steel pipe pile is carried out by adopting a pile sinking auxiliary positioning mechanism;

the pile sinking auxiliary positioning mechanism is provided with a plurality of positioning auxiliary sleeve pipe sets which correspond to the steel pipe piles to be constructed in a pile sinking mode one by one, the positioning auxiliary sleeve pipe sets are all installed and fixed on the positioning auxiliary support, the positioning auxiliary sleeve pipe sets are provided with two positioning auxiliary sleeve pipes which are coaxially arranged from top to bottom, and the inner diameter of each positioning auxiliary sleeve pipe is slightly larger than the outer diameter of each steel pipe pile.

Images