CN216108586U

CN216108586U - Novel pile foundation scour prevention protective structure

Info

Publication number: CN216108586U
Application number: CN202122521348.3U
Authority: CN
Inventors: 黄晓敏; 谢红忠; 徐成剑; 张仲伟
Original assignee: Changjiang Institute of Survey Planning Design and Research Co Ltd
Current assignee: Changjiang Institute of Survey Planning Design and Research Co Ltd
Priority date: 2021-10-20
Filing date: 2021-10-20
Publication date: 2022-03-22
Anticipated expiration: 2031-10-20

Abstract

The utility model provides a novel pile foundation anti-scouring protection structure which comprises geotextile, a rubble layer and mould bag concrete, wherein the geotextile is flatly paved on a riverbed or a seabed around a pile foundation of a steel pipe pile and used for reducing the flow of silt and broken stone on the bed surface around the pile foundation; the stone throwing layer is laid on the upper part of the geotextile within the range of the scouring pit around the pile foundation, and the scouring pit around the pile foundation is filled; the mould bag concrete is positioned on the upper parts of the geotextile and the riprap layer, and concrete or cement mortar is poured into the mould bag through a high-pressure pump, so that a mould bag concrete integral structure with certain strength is formed after the mould bag concrete is solidified. The utility model has convenient construction, good application effect and strong adaptability, and can be widely applied to pile foundation protection of structures such as cross-sea bridges, ocean platforms, offshore wind power and the like. Each protective layer is tightly attached, the integrity is good, and the anti-scouring capability can be effectively improved.

Description

Novel pile foundation scour prevention protective structure

Technical Field

The utility model relates to the field of pile foundation protection in ocean engineering or bridge engineering, in particular to a novel pile foundation anti-scouring protection structure.

Background

Offshore wind power is continuously developed and matured in recent years, plays an important role in renewable energy technology, and attracts wide attention all over the world. With the rapid development of offshore wind power development in China, a large-diameter single-pile foundation is widely applied. In a complex marine environment, structures such as pile foundations can change the local flow field distribution, thereby causing the conditions of local flow velocity increase, vortex-induced vibration and the like, and even aggravating the transportation of silt to form scouring. Therefore, the scouring condition of the pile foundation is increasingly severe, the stability of the pile foundation is damaged, and a reasonable and applicable scouring prevention scheme is selected, so that the method has important significance for long-period safe and stable operation of the wind power plant and guarantee of economic benefits.

Under the action of sea currents and waves, the large-diameter steel pipe pile foundation of the offshore wind turbine changes the local hydrodynamic conditions, vortices which are impacted by water flows or rotate at high speed are locally generated around the pile, and the water flows or the vortices have high scouring capacity, so that local scouring is formed around the pile foundation, and the large-diameter steel pipe pile foundation is unfavorable for the pile foundation and an upper fan. According to the scouring principle, the wave current scouring and seabed erosion jointly act to form a scouring pit around the foundation pile, the larger the diameter of the pile foundation is, the more serious the scouring is, and therefore, it is necessary to take measures to prevent or slow down the influence of the scouring on the pile foundation.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problems, the utility model provides a novel pile foundation anti-scouring protection structure which is excellent in anti-scouring performance and can ensure the safety and stability of an upper fan. And the integral performance is good, the construction is simple, the offshore operation time is short, and the device can adapt to various complex terrains.

The technical scheme of the utility model is as follows:

a novel pile foundation anti-scouring protection structure comprises geotextile, a stone throwing layer and mould bag concrete,

the geotextile is laid on a riverbed or a seabed around the pile foundation of the steel pipe pile to reduce the flow of silt and broken stone on the bed surface around the pile foundation;

the stone throwing layer is laid on the upper part of the geotextile within the range of the scouring pit around the pile foundation, and the scouring pit around the pile foundation is filled;

the mould bag concrete is positioned on the upper parts of the geotextile and the riprap layer, and concrete or cement mortar is poured into the mould bag through a high-pressure pump, so that a mould bag concrete integral structure with certain strength is formed after the mould bag concrete is solidified.

The geotextile is 30kN/m woven geotextile, and the laying range can completely cover the scoured pits around the pile foundation.

The riprap layer adopts a bagged lump stone or a direct riprap filling mode, and the grain size of the lump stone of the riprap layer is 5-15 cm.

The rubdown layer fills and levels the scouring pit, and the filling height does not exceed the natural height of the seabed or the riverbed.

The thickness of the mould bag concrete is 20-50 cm.

Compared with the prior art, the utility model has the beneficial effects that: with the gradual development of the offshore wind turbine towards deep hydration and large-scale, the water flow velocity at the pile foundation is gradually increased, so that the cost of anti-scouring measures is higher and higher.

The utility model has wide application range and simple and safe construction, the thickness of the concrete in the mold bag can be controlled by restricting the hanging ribs in the mold bag, and one-time spray irrigation molding is usually adopted. When the wind power foundation is located in an area with larger water depth, the mould bag concrete can also be directly subjected to underwater pouring construction.

The utility model has strong anti-scouring capability, the mould bag concrete at the uppermost layer forms a mould bag concrete integral structure with certain strength after being solidified, and forms a rigid plate-shaped anti-scouring block together with the geotextile and the riprap layer which are laid previously, the rigid plate-shaped anti-scouring block is attached to the seabed and is tightly attached to a pile foundation, scouring points are not easy to generate, and the effect of resisting wave damage is obvious.

Drawings

FIG. 1 is a schematic view of the construction of the geotextile and gravel layer of the present invention;

FIG. 2 is an overall structural view of the present invention;

figure 3 is a three-dimensional cross-sectional view of the erosion protection design of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-3, the present invention provides a technical solution:

a novel pile foundation anti-scour protection structure comprises a geotextile 3, a stone throwing layer 4 and a mould bag concrete 5,

the geotextile 3 is paved on a riverbed or a seabed 1 around the pile foundation of the steel pipe pile 2 to reduce the flow of silt and broken stone on the bed surface around the pile foundation;

the stone throwing layer 4 is laid on the upper part of the geotextile 3 in the range of the scouring pit around the pile foundation, and the scouring pit around the pile foundation is filled;

and the mould bag concrete 5 is positioned on the upper parts of the geotextile 3 and the riprap layer 4, and concrete or cement mortar is poured into the mould bag through a high-pressure pump, so that a mould bag concrete integral structure with certain strength is formed after the mould bag concrete is solidified.

The geotextile 3 is a 30kN/m woven geotextile, and the laying range can completely cover the scoured pits around the pile foundation. The geotextile 3 is processed according to the laying range on the basis of geotextile produced by manufacturers. The paving is carried out according to the water flow direction, the paving is ensured to be uniform, and no edge curling or folding is generated.

The riprap layer 4 adopts a bagged lump stone or a direct riprap filling mode, and the grain size of the lump stone of the riprap layer 4 is 5-15 cm.

The rubble layer 4 fills and levels the scour pit, and the filling height does not exceed the natural height of the seabed or the riverbed.

The thickness of the mould bag concrete 5 is 20-50 cm. The strength of the mould bag concrete can bear stronger bed surface water flow velocity and 300Pa shear stress, and the uplifting force borne by the mould bag concrete is smaller than the underwater self weight of the mould bag concrete. The mould bag concrete need detect concrete mobility and product completion in the work progress, through reasonable proportion design, does not appear segregation bleeding again when realizing the high mobility of concrete.

During the specific construction and use process, firstly, the geotextile 3 is laid around the scouring pit on the seabed 1, meanwhile, the geotextile is temporarily fixed by using broken stones or bagged sand, after a diver performs launching inspection, a long-arm excavator or an open barge is used for throwing broken stones, and a broken stone layer 4 is laid. The construction process of the mould bag concrete 5 at the uppermost layer generally comprises two methods, namely a 'paving-before-pouring method' and a 'pouring-before-pouring method'. The construction operation of the 'paving before pouring' method is relatively simple, but is greatly influenced by the environment, is particularly limited by the water quality to the underwater visibility of divers, and water in the mold bags needs to be extruded out through concrete, so that the underwater concrete filling speed is relatively slow, the difficulty in controlling the strength and compactness of the concrete is relatively high, and after the construction is finished, the underwater concrete is well attached to a structure and the construction effect is good. The 'pouring-before-laying method' slowly drags and drops the mould bag concrete into water through the slide way, so that the strength and compactness of the concrete can be better ensured, the filling speed is high, more equipment is required to be put into the mould bag at one time, the slope protection engineering is more in application, and the mould bag concrete is not suitable for bottom protection with larger water depth and less engineering quantity. The construction of the mould bag concrete related in the utility model usually adopts a 'paving before pouring method'.

In this example, concrete is pumped by a concrete pump on board the vessel through a hose of about 7cm diameter into a submerged formwork. Firstly, a diver enters water to check a paved mould bag, a hose opening is inserted into the cuffs of the mould bag under the water, a pump pipe is moved to the next cuff to continue to be filled after the cuff accessory concrete is filled, the pump pipe in the cuff is immediately bound after being moved out, and finally whether the concrete mould bag is successfully filled or not is confirmed, and the filling quality of the mould bag is checked.

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

Claims

1. A novel pile foundation anti-scour protection structure is characterized by comprising geotextile (3), a stone throwing layer (4) and mould bag concrete (5),

the geotextile (3) is paved on a riverbed or a seabed (1) around the pile foundation of the steel pipe pile (2) to reduce the flow of silt and broken stone on the bed surface around the pile foundation;

the stone throwing layer (4) is laid on the upper part of the geotextile (3) in the range of the scouring pit around the pile foundation, and the scouring pit around the pile foundation is filled;

and the mould bag concrete (5) is positioned at the upper parts of the geotextile (3) and the riprap layer (4), and concrete or cement mortar is poured into the mould bag through a high-pressure pump, so that the mould bag concrete integral structure with certain strength is formed after the mould bag concrete is solidified.

2. A novel pile foundation anti-scour protection structure according to claim 1, wherein the geotextile (3) is a 30kN/m woven geotextile, and the laying range can completely cover scour pits around the pile foundation.

3. A novel pile foundation anti-scour protection structure according to claim 1, wherein the rubble layer (4) is in the form of bagged lump stones or direct rubble, and the grain size of the rubble layer (4) is 5-15 cm.

4. A novel pile foundation anti-scour protection structure according to claim 1, wherein the rubble layer (4) fills and levels the scour pit to a level not exceeding the natural height of the seabed or riverbed.

5. A novel pile foundation anti-scouring protection structure according to claim 1, wherein the thickness of the mould bag concrete (5) is 20-50 cm.