Out-of-cylinder pile distributed composite foundation-cylinder type offshore wind power foundation and construction method

Abstract

The invention relates to an out-of-cylinder pile distributed composite foundation-cylinder type offshore wind power foundation and a construction method. The out-of-cylinder pile distributed compositefoundation-cylinder type offshore wind power foundation is suitable for a sea area with soft soil such as thick sludge, mucky soil and silt covering the offshore surface layer in China. The wind power foundation comprises a concrete transition section, a composite cylinder type foundation, a concrete circular bottom plate and cylinder periphery piles. The composite cylinder type foundation is ofa lower-opening cavity multi-branch-bin structure and sinks in the soft soil of the surface layer, the cylinder top makes contact with the mud surface, and the cylinder periphery piles are evenly distributed on the periphery of the composite cylinder type foundation. The advantages of underwater deep cement mixing piles (or sand compaction piles) and the advantages of the cylinder type foundationare combined, the bearing area of the cylinder type foundation is large, stability is good, and piling is not needed; but under the condition of the soft soil, the cylinder type foundation is large insedimentation and inclination, the cement piles (or the sand compaction piles) are arranged in the cylinder type foundation, the foundation deformation problem of the cylinder type foundation is solved, the manufacturing size of a suction cylinder is reduced, and the foundation manufacturing cost is reduced.

Description

technical field [0001] The present invention relates to an offshore wind power foundation structure, in particular to a composite foundation with piles arranged outside the cylinder-tube offshore wind power foundation and its construction method. Background technique [0002] Based on the soft foundation conditions such as silt and silty clay in most of my country's offshore areas, generally in order to meet the requirements of foundation bearing capacity and foundation deformation, traditional pile foundations such as single pile foundations and jacket foundations are usually used. These two foundation forms require Large-scale hoisting ships and piling ships assist in the construction. By hammering piles, the piles penetrate the weak soil layer and enter the better bearing layer. This traditional pile foundation has a high cost and a long construction period. [0003] With the increase of the unit capacity of offshore wind turbines, the use of traditional monopile and jacke...

AI Technical Summary

Problems solved by technology

[0002] Based on the soft foundation conditions such as silt and silty clay in most of my country's offshore areas, generally in order to meet the requirements of foundation bearing capacity and foundation deformation, traditional pile foundations such as single pile foundations and jacket foundations are usually used. These two foundation forms require Large-scale hoisting ships and piling ships assist in the construction. By hammering piles, the piles penetrate the weak soil layer and enter the better bearing layer. This traditional pile foundation is expensive and has a long construction period.

[0003] With the increase of the unit capacity of offshore wind turbines, the use of traditional monopile and jacket foundations requires an increase in the size and material consumption of the foundation, and the limitation of large-diameter single-pile piling by construction equipment has become an insurmountable problem. To solve this problem, The suction composite cylindrical foundation as described in patent CN107761755A and patent CN106759445 is gradually being used in offshore wind power. The negative pressure sinking installation method of the cylindrical foundation (as shown in the patent CN105926661A) avoids the cumbersome piling process, and the cylindrical foundation is due to Its mechanical characteristics and construction methods are suitable for soil layers such as clay and sandy soil with a certain bearing capacity. For silt and muddy soil layers with poor bearing capacity, the diameter of the tube needs to be increased if the tube foundation is used, and because the tube type The weight of the foundation and the load of the fan increase, which brings the problem of large foundation settlement and inclination deformation. If the size of the cylindrical foundation is excessively increased, not only the cost will be increased, but also the one-step installation cannot be realized (as shown in the patent CN102926949A), which is economical The advantages over monopile and jacket no longer exist

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