CN-121976576-A - Multi-limb diagonal bracing reinforcing system for machine changing and capacity increasing of old single pile foundation and construction method

CN121976576ACN 121976576 ACN121976576 ACN 121976576ACN-121976576-A

Abstract

The invention provides a multi-limb diagonal bracing reinforcing system for machine changing and capacity increasing of an old single pile foundation and a construction method. The reinforcement system comprises an outer sleeve, a supporting structure and a foundation anchoring structure, wherein the outer sleeve, the supporting structure and the foundation anchoring structure are sleeved outside the original single pile foundation. The inner wall of the outer sleeve is provided with a shear key, the supporting structure comprises a supporting seat and at least three inclined struts, the supporting seat is arranged on the periphery of the outer sleeve, the upper end of each inclined strut is hinged with the corresponding supporting seat through a first pin shaft, and the lower end of each inclined strut is hinged with the corresponding suction anchor through a second pin shaft. The reinforcing girder and the central cylinder which are distributed radially are arranged below the suction anchor top cover. The construction method realizes in-situ reinforcement by grouting and locking between the outer sleeve and the original single pile foundation and hinging and matching with the double pin shafts. The invention improves the overall rigidity of the foundation by cooperatively sharing the unit load after the capacity-increasing of the machine-changing through multiple parts, solves the problem that the prior art depends on preset convex rings or underwater welding, reduces the requirement on the construction alignment precision, and is suitable for reinforcing and reforming the offshore wind turbine foundation.

Inventors

WANG PIGUANG
SUN PENGYU
DONG JIANWEI

Assignees

北京工业大学

Dates

Publication Date: 20260505
Application Date: 20260409

Claims (10)

1. A multi-limb diagonal bracing reinforcement system for the capacity increment of an old single-pile foundation machine is characterized by comprising an outer sleeve, a supporting structure and a foundation anchoring structure; The outer sleeve is used for being sleeved outside the original single pile foundation, and the inner wall of the outer sleeve is provided with a shear key; the support structure comprises a support seat and at least three inclined struts, wherein the support seat is arranged on the periphery of the outer sleeve and is fixedly connected with the outer sleeve; the foundation anchoring structure comprises suction anchors which are in one-to-one correspondence with the inclined struts, and the lower end parts of the inclined struts are respectively hinged with the corresponding suction anchors through second pin shafts.
2. The multi-limb diagonal bracing reinforcing system for the capacity-increasing of the old single-pile foundation machine according to claim 1, wherein the upper end edge and the lower end edge of the outer sleeve are respectively provided with a flared structure.
3. The multi-limb diagonal bracing reinforcing system for the capacity-increasing of the old single-pile foundation machine according to claim 1, wherein the middle part of the outer sleeve is an equal-diameter section, and the shear key is a spiral shear key arranged on the inner wall of the equal-diameter section.
4. The multi-limb diagonal bracing reinforcing system for the capacity-increasing of the old single-pile foundation machine according to claim 2, wherein the supporting seat comprises an upper horizontal reinforcing ring, a lower horizontal reinforcing ring and a plurality of groups of ear plates fixedly connected between the upper horizontal reinforcing ring and the lower horizontal reinforcing ring, wherein the upper horizontal reinforcing ring and the lower horizontal reinforcing ring are arranged along the circumferential direction of the outer sleeve, and a preset stress avoiding interval is reserved between the supporting seat and the bell mouth structure.
5. The multi-limb diagonal bracing reinforcing system for the capacity-changing of the old single-pile foundation according to claim 4, wherein vertical reinforcing rib plates are welded between the upper horizontal reinforcing ring and the lower horizontal reinforcing ring, and the plurality of groups of lug plates, the upper horizontal reinforcing ring, the lower horizontal reinforcing ring and the vertical reinforcing rib plates and the outer wall of the outer sleeve form a space box-type bearing structure together.
6. The multi-limb diagonal bracing reinforcing system for the capacity-changing of the old single-pile foundation according to claim 5, wherein each group of the ear plates comprises two mutually parallel vertical plates, and the vertical plates are perpendicular to the outer wall surface of the outer sleeve.
7. The multi-limb diagonal bracing reinforcing system for the capacity-changing of the old single-pile foundation according to claim 1, wherein a bearing plate is arranged at the top of the suction anchor, an ear plate structure used for being connected with the lower end part of the diagonal bracing is arranged on the bearing plate, and stiffening ribs which are symmetrically arranged are arranged between the ear plate structure and the bearing plate.
8. The multi-limb diagonal bracing reinforcing system for the capacity-increasing of the old single-pile foundation machine according to claim 7, wherein reinforcing girders and central cylinders which are radially distributed are arranged below the bearing plate, the central cylinders are positioned at the geometric center below the bearing plate, the inner side ends of the reinforcing girders are respectively welded to the outer wall surface of the central cylinders, and the outer side ends of the reinforcing girders are respectively welded to the inner side surfaces of the side walls of the suction anchors.
9. The multi-limb diagonal bracing reinforcing system for the capacity-increasing of the old single-pile foundation machine according to claim 1, wherein the number of the diagonal braces is four, the number of the suction anchors is four, and the four diagonal braces are symmetrically distributed along the periphery of the outer sleeve in the circumferential direction.
10. A method of constructing a multi-limb diagonal bracing reinforcement system for machine change compatibilization of old single pile foundations as claimed in any one of claims 1 to 9, comprising the steps of: S1, cleaning attachments on the outer wall of the original single pile foundation, and measuring and determining a reinforcing area; S2, lifting the outer sleeve and sleeving the outer sleeve outside the original single pile foundation, so that an annular gap is maintained between the outer sleeve and the original single pile foundation; S3, grouting slurry into the annular gap to form a high-strength grouting layer, and realizing non-welding locking of the outer sleeve and the original single pile foundation through mutual engagement of the high-strength grouting layer and the shear key; s4, sinking and penetrating the suction anchor into the seabed around the original single pile foundation; s5, the upper end parts of the inclined struts are hinged with the corresponding supporting seats through the first pin shafts respectively, and the lower end parts of the inclined struts are hinged with the corresponding suction anchors through the second pin shafts respectively.

Description

Multi-limb diagonal bracing reinforcing system for machine changing and capacity increasing of old single pile foundation and construction method Technical Field The invention relates to the field of offshore wind turbine foundation reinforcement, in particular to a multi-limb diagonal bracing reinforcement system for machine changing and capacity increasing of an old single-pile foundation and a construction method. Background With the development of the offshore wind power industry, a batch of offshore wind turbines built in early stage gradually enter the middle and later stages of service. The implementation of machine changing and capacity increasing on the basis of the existing machine position becomes an important way for improving the power generation capacity of the unit sea area of the wind field. The single-machine capacity of the new generation offshore wind turbine is increased, and the running load of the unit is obviously higher than that of the early-stage unit. The original single pile foundation generally only meets the initial service requirement, and if a large-capacity unit is directly replaced without effective treatment, the foundation may have the problems of insufficient bearing margin, deteriorated power response and the like. The prior reinforcement technology, such as a single pile foundation post-installation reinforcement device disclosed in CN112814021B, is mainly connected with a diagonal brace through a lantern ring. However, such a solution is highly dependent in practice on a plurality of projecting rings which are welded beforehand to the pile body in advance of the manufacture of the single pile. For old single pile foundations which are already in service for many years, the surface of the foundation is not preset with the convex ring, and the offshore complex deep water environment makes the process of underwater repair welding the convex ring complex, the cost is high, a heat affected zone is extremely easy to generate, and the original structural integrity is weakened. Furthermore, without a reliable non-welded locking interface, simple ferrule connections are difficult to handle with increased overturning moment and cyclic loading after capacity increases in the change. Therefore, how to provide a reinforcement system and a construction method which can be applied to an old single pile foundation without a preset structure, have high reliable force transmission capacity and high construction tolerance, and are a technical problem to be solved in the field. Disclosure of Invention Aiming at the problems of insufficient bearing capacity, difficult construction alignment and the like of an old offshore wind turbine single pile foundation under the working condition of machine changing and capacity increasing, the invention provides a multi-limb diagonal bracing reinforcing system for machine changing and capacity increasing of the old single pile foundation and a construction method. The multi-limb diagonal bracing reinforcing system for the capacity-increasing of the old single-pile foundation comprises an outer sleeve, a supporting structure and a foundation anchoring structure, wherein the outer sleeve is sleeved outside the original single-pile foundation, a shear key is arranged on the inner wall of the outer sleeve, the supporting structure comprises a supporting seat which is arranged on the periphery of the outer sleeve and fixedly connected with the outer sleeve, at least three diagonal bracing pieces, the upper end parts of the diagonal bracing pieces are respectively hinged with the corresponding supporting seats through first pin shafts, the foundation anchoring structure comprises suction anchors which are in one-to-one correspondence with the diagonal bracing pieces, and the lower end parts of the diagonal bracing pieces are respectively hinged with the corresponding suction anchors through second pin shafts. Therefore, the shear key on the inner wall of the outer sleeve is suitable for grouting to form a reliable locking interface at the periphery of the original single pile foundation, the reinforcing problem that the old single pile has no preset convex ring and cannot be welded is solved, and the load generated by the unit after capacity expansion is transferred to the peripheral suction anchor foundation through the outer sleeve and the inclined struts, so that a multi-path collaborative stress system is formed, and the stress state of the original foundation is remarkably improved. At least three diagonal braces are set to form a stable space supporting framework, and the overturning moment is resisted in all directions. Further, the upper end edge and the lower end edge of the outer sleeve are respectively provided with a flared bell mouth structure. Therefore, the flare structure slows down the rigidity abrupt change at the reinforced boundary, and effectively avoids the phenomenon of stress cutting on the original pile at the two ends of the rein