Construction method of scouring silt solidified soil template for offshore wind power foundation

Abstract

The application discloses a construction method of a scouring silt solidified soil template for an offshore wind power foundation, relates to the field of scouring silt solidified soil for offshore wind power, and comprises the following steps: step 1, preliminary preparation: terrain measurement is conducted on a seabed plane around a foundation pile 1 by using an airborne laser detection technology, and whether a scouring pit 2 has been formed around the foundation pile 1 is checked; step 2, template prefabrication; step 3, template splicing; and step 4, filling of internal materials of the template. The application has the advantages that the kenaf fiber or jute fiber geotextile is a kind of green environmental protection material which is degradable, high in strength, corrosion resistant, high in seabed deformation adaptability and low in cost; the kenaf fiber or jute fiber geotextile, as the template, can not only protect the internal silt solidified soil, but also does not need to be recycled in the later period, and has a good market application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of offshore wind power solidified soil anti-scour, in particular to a construction method of offshore wind power foundation anti-scour silt solidified soil formwork. BACKGROUND

[0002] With the strong support of national policy, the new energy industry represented by offshore wind power has grown rapidly. However, after the construction of offshore wind power piles, the foundation pile changes the original hydrodynamic conditions of the sea area, and the foundation pile is subjected to strong scouring effect. If no protection is taken, scouring pits will gradually form, which will have irreversible impact on the stability of the foundation pile. Therefore, it is necessary to take necessary protection around the foundation pile of offshore wind power piles to resist the scouring of seawater.

[0003] Silt solidified soil is an underwater anti-scouring environmental composite material with high fluidity and slightly stronger early strength than seabed silt. It has superior performance in underwater foundation pile protection that other materials cannot match. However, due to its high fluidity and low strength, the silt solidified soil is greatly affected by water flow during construction, often accompanied by a large amount of material loss, uneven material filling, and uncontrollable protection range.

[0004] Traditional offshore wind power pile anti-scouring protection measures mainly include three types: sand and stone filling, ring protection, and anti-scouring solidified soil. However, each of them has many shortcomings. For the first two, not only is the maintenance amount large, but they are also prone to loss, limited protection effect, and more importantly, they are prone to secondary scouring, which has a huge impact on the wind power foundation pile. SUMMARY

[0005] In order to solve the problems of material loss, uneven material filling, and uncontrollable protection range caused by the high fluidity and low early strength of silt solidified soil, a construction method of offshore wind power foundation anti-scouring silt solidified soil formwork is proposed.

[0006] A construction method of offshore wind power foundation anti-scouring silt solidified soil formwork, comprising:

[0007] Step 1: preliminary preparation: use airborne laser detection technology to measure the terrain of the seabed plane around the foundation pile 1, and check whether a scouring pit 2 has been formed around the foundation pile 1; if the seabed plane has not formed a scouring pit 2, directly implement step 2; if the seabed plane has a scouring pit 2, sew single-layer jute fiber geotextile or single-layer red fiber geotextile into small sand bags 3 by an industrial sewing machine, pump silt solidified soil into the small sand bags 3 by a slurry pump 6, fill the scouring pit 2 around the foundation pile 1 with the small sand bags 3 filled with silt solidified soil, and the filling standard is that the seabed plane around the foundation pile 1 is flush with the seabed plane.

[0008] Step 2: Template prefabrication: In advance, single-layer jute fiber geotextile or single-layer red fiber geotextile is sewn into two identical closed semicircular ring sand bags 4 with an inner radius of 5 meters and an outer radius of 30 meters by an industrial sewing machine in the factory, facilitating direct application at the construction site later; the inside height of the closed semicircular ring sand bag 4 is 1 meter, and the outside height is 0 meter; a foundation pile penetration hole 401 with a length of 1 meter, a width of 0.5 meters, and an interval of 1 meter is reserved in advance at a distance of 0.3 meters from the inside joint surface of the closed semicircular ring sand bag 4, reserving enough space for the installation of the connecting device 407 later, and a mud injection port 402 is reserved on each closed semicircular ring sand bag 4; the outer ring 403 of the closed semicircular ring sand bag 4 is sewn from single-layer jute fiber geotextile or single-layer jute fiber geotextile, and the inner ring 404 is sewn from double-layer jute fiber geotextile or double-layer jute fiber geotextile, the surface of the closed semicircular ring sand bag 4 adopts a combination of concave parts 405 and convex parts 406, combining active protection with passive protection; the connecting device 407 is made of stainless steel material and can be prefabricated by the factory, then transported to the construction site for direct installation.

[0009] Step 3: Template splicing: AB two working surfaces are used to complete the splicing of jute fiber geotextile template or red fiber geotextile template, working surface A uses a full-rotation loading machine and a fixed boom crane ship to jointly work, and the prefabricated connecting device 407 is hoisted around the foundation pile 1; working surface B is responsible for splicing the two semicircular ring sand bags 4 around the foundation pile 1 through the connecting device 407 by workers on the construction ship, and two long mud injection pipelines 5 are fixedly connected with the mud injection ports 402 on the two semicircular ring sand bags 4, and then the template is freely settled to the seabed plane in seawater through its own gravity.

[0010] Step 4: Filling the internal material of the template: workers on the construction ship pump sludge solidified soil into the interior of the two semicircular ring sand bags 4 through two mud pumps 6, and after the two semicircular ring sand bags 4 are filled, the connection between the mud injection port 402 and the mud injection pipeline 5 is disconnected, and then the mud injection port 402 is closed.

[0011] The application also has the following additional technical features:

[0012] As a further specific optimization of the technical solution of the application: in step 1, if a protrusion is detected on the seabed plane around the foundation pile 1, the protrusion should be cleaned.

[0013] As the further specific optimization of the technical scheme of the present application: in step 2, the template prefabrication comprises: step 2.1: the single-layer jute fiber geotextile or single-layer red fiber geotextile is laid straight and flat, and is cut according to the size required by the small sand bag 3; step 2.2: thread is drawn at each sewing position, and is sewn by overlock sewing; the small sand bag 3 is sealed by lead wire after being filled with silt solidified soil; step 2.3: the jute fiber geotextile or red fiber geotextile is laid straight and flat, and is cut according to the size required by the two semi-circular ring sand bags 4, and at the same time, a rectangular through hole is reserved in advance at a distance of 0.3 meters from the inside splicing surface of the closed semi-circular ring sand bag 4 during cutting; step 2.4: the connecting device 407 is composed of two identical components, and the two components are generally processed from a stainless steel plate 4071, the bottom of the component is the stainless steel plate 4071, the upper part is uniformly distributed with a hollow stainless steel body 4072 composed of stainless steel, and the upper part of the hollow stainless steel body 4072 is formed in a round corner shape; at the same time, a circular ring 4073 is reserved on the upper part of the hollow stainless steel body 4072, and a steel cable 4074 is bound after the template splicing is completed on the construction site; step 2.5: thread is drawn at each sewing position, and is sewn by overlock sewing, and the four surfaces around the rectangular through hole reserved for the convenient installation of the connecting device 407 in the later period must be sewn with the jute fiber geotextile or red fiber geotextile.

[0014] As the further specific optimization of the technical scheme of the present application: in step 2.3, a shrinkage allowance is reserved during cutting, and the cutting size has a surplus amount, and at the same time, the slurry injection port 402 adopts an internal buckle type pipe tooth interface, and after the silt solidified soil is pumped, the connection can be directly disconnected, and the special structure can ensure that seawater cannot be poured in.

[0015] As the further specific optimization of the technical scheme of the present application: in step 2.3, after the template splicing is completed, the steel cable 4074 is bound by workers on the construction site.

[0016] The construction method of the present application combines geotextile and silt solidified soil for use in offshore wind power foundation scouring resistance, and has the following beneficial effects: the present application combines jute fiber geotextile or red fiber geotextile with silt solidified soil, uses two semi-circular ring red fiber or jute fiber geotextile bags as a template, and fills the inside with silt solidified soil, which can effectively solve the above problems, and the jute fiber geotextile or red fiber geotextile is a kind of green and environmentally friendly material with degradable, high strength, corrosion resistance, strong sea bed deformation adaptability and low cost, which can not only protect the internal silt solidified soil as a template, but also does not need to be recycled in the later period, and has good market application and promotion prospects.

[0017] Additional aspects and advantages of the present application will be given in the following description of the appendix part, and some will become apparent from the following description, or can be understood through practice. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic diagram of a template installation structure of the sludge solidified soil of the present application;

[0019] Figure 2 is a schematic diagram of a template size structure of the sludge solidified soil of the present application;

[0020] Figure 3 is a schematic diagram of a semi-circular sand bag 4 structure of the present application;

[0021] Figure 4 is a schematic diagram of a semi-circular sand bag 4 connection structure of the present application;

[0022] Figure 5 is a schematic diagram of a connection device 407 structure of the present application;

[0023] Figure 6 is a schematic diagram of a connection device 407 structure of the present application;

[0024] Figure 7 is a schematic diagram of a single connection device 407 front view structure of the present application;

[0025] Figure 8 is a schematic diagram of a slurry injection port 402 structure of the present application;

[0026] Figure 9 is a schematic diagram of a construction structure of the sludge solidified soil template of the present application. DETAILED DESCRIPTION

[0027] This part will describe the specific embodiments of the present application in detail, and the drawing part can make people have an intuitive understanding of the overall technical scheme of each technology of the present application, but cannot be understood as limiting the protection scope of the present application.

[0028] A construction method of a scour-resistant sludge solidified soil template for an offshore wind power foundation, comprising:

[0029] Step 1: preliminary preparation: using airborne laser detection technology to measure the terrain of the seabed plane around the foundation pile 1, and checking whether the seabed plane around the foundation pile 1 has formed a scour pit 2 as shown in Figure 1 In step 1, if it is detected that there is a protrusion on the seabed plane around the foundation pile 1, the protrusion should be cleaned.

[0030] If the seabed plane has not formed a scour pit 2 as shown in Figure 1 : directly implement the following steps.

[0031] If the seabed plane has already existed a scour pit 2 as shown in Figure 1The shown scouring pit 2: through the industrial sewing machine, the single layer of jute fiber geotextile or the single layer of red fiber geotextile is sewn into a small sand bag 3, the sludge solidified soil is pumped into the small sand bag 3 by the slurry pump 6, and the small sand bag 3 filled with the sludge solidified soil is used to fill the scouring pit 2 around the foundation pile 1, and the filling standard is that the foundation pile 1 is flush with the seabed plane.

[0032] Step 2: template prefabrication: in advance, in the factory, through the industrial sewing machine, the single layer of jute fiber geotextile or the single layer of red fiber geotextile is sewn into a small sand bag 3, the sludge solidified soil is pumped into the small sand bag 3 by the slurry pump 6, and the small sand bag 3 filled with the sludge solidified soil is used to fill the scouring pit 2 around the foundation pile 1, and the filling standard is that the foundation pile 1 is flush with the seabed plane. Figure 2 and Figure 3 As shown, two completely identical closed semicircular ring sand bags 4 with an inner circle radius of 5 meters and an outer circle radius of 30 meters are prefabricated in advance, which are convenient for direct application at the construction site in the later stage. The inner side height of the closed semicircular ring sand bag 4 is 1 meter, and the outer side height is 0 meter. As shown, a foundation pile penetration hole 401 with a length of 1 meter, a width of 0.5 meters and an interval of 1 meter is reserved in advance at a distance of 0.3 meters from the inner side joint surface of the closed semicircular ring sand bag 4, which reserves enough space for the installation of the connecting device 407 in the later stage as shown in Figure 3 and Figure 5 and Figure 6 As shown, a slurry inlet 402 is reserved on each closed semicircular ring sand bag 4, and the internal structure diagram is shown in Figure 1 Figure 8 .

[0033] The outer ring 403 of the closed semicircular ring sand bag 4 is sewn by a single layer of jute fiber geotextile or a single layer of jute fiber geotextile, and the inner ring 404 is sewn by a double layer of jute fiber geotextile or a double layer of jute fiber geotextile. The surface of the closed semicircular ring sand bag 4 adopts the design concept of combining concave parts 405 and convex parts 406 to meet the requirement of reducing the flow rate of seawater around the foundation pile 1, and combines active protection with passive protection. The specific structure diagram is shown in Figures 1-4 .

[0034] The connecting device 407 is entirely cast from stainless steel material, which can be prefabricated by relevant units. The specific structure is shown in Figure 5 and Figure 6 which can be directly installed at the construction site in the later stage, so as to greatly reduce the construction cost and construction period.

[0035] In step 2, the template prefabrication includes:

[0036] Step 2.1: The single layer of jute fiber geotextile or the single layer of red fiber geotextile is laid flat and straight, and is cut according to the size required by the small sand bag 3.

[0037] Step 2.2: thread at each sewing place, sew with overlock method; after the small sand bag 3 is filled with sludge solidified soil, it is sealed with lead wire.

[0038] ​Step 2.3: The jute fiber geotextile or kenaf fiber geotextile is laid flat and straight, and is cut to the size required by the closed semicircular ring sand bag 4 with the two inner circle radius of 5 meters, the outer circle radius of 30 meters, the 2 meters of the outer ring 404 as a single layer, the inner ring 403 as a double layer, the inner side height of 1 meter, the outer side height of 0 meter, and the surface concave-convex combination. At the same time, a rectangular through hole with a length of 1 meter, a width of 0.5 meter and an interval of 1 meter is reserved 0.3 meters away from the inner side joint surface of the closed semicircular ring sand bag 4 in advance to reserve enough space for the installation of the connecting device 407 in the later stage. The specific structure of the two semicircular ring sand bags 4 is shown in Figure 3 and Figure 4 .

[0039] In step 2.3, after the template splicing is completed, the 12mm steel cable 4074 is bound by workers at the construction site;

[0040] In step 2.3, the shrinkage allowance is reserved during cutting, and the cutting size has a surplus amount. At the same time, the slurry inlet 402 adopts an internal buckle type pipe tooth interface, and after pumping the sludge solidified soil, the connection can be directly disconnected, and its special structure can ensure that seawater cannot be poured in. The internal specific structure diagram is shown in Figure 8 .

[0041] Step 2.4: The connecting device 407 is composed of two identical components, and the two components are generally processed from a stainless steel plate 4071. The component bottom is a stainless steel plate 4071 with a length of 25 meters, a width of 3.6 meters and a thickness of 30mm. The upper part is uniformly distributed with a hollow stainless steel body 4072 composed of a stainless steel with a thickness of 20mm, a length of 1 meter, a width of 0.5 meter and a height of 1 meter. The upper part of the hollow stainless steel body 4072 is formed in a round corner shape to prevent stress concentration and damage to the component. At the same time, a circular ring 4073 with a diameter of 10mm is reserved on the upper part of the hollow stainless steel body 4072 to facilitate the binding of the steel cable 4074 with a diameter of 12mm after the template splicing is completed at the construction site.

[0042] Step 2.5: Thread the line at each sewing place, and sew with the overlock method. At the same time, the four sides around the rectangular through hole reserved for the convenient installation of the connecting device 407 must be sewn with jute fiber geotextile or kenaf fiber geotextile to ensure that the two semicircular ring sand bags 4 are completely closed.

[0043] Step 3: Template splicing: AB two working surfaces complete the splicing of jute fiber geotextile template or kenaf fiber geotextile template, working surface A is jointly operated by full slewing loading machine and fixed boom crane ship to hoist the prefabricated connecting device 407 around the foundation pile 1; working surface B is responsible for splicing two half-ring sand bags 4 around the foundation pile 1 through the connecting device 407 by workers on the construction ship, at the same time, two long enough mud injection pipelines 5 are fixedly connected with the mud injection openings 402 on the two half-ring sand bags 4, and then the template is freely settled to the seabed plane in seawater through its own gravity. It should be noted that the working ship position is reasonably arranged, which maintains 3-5 m with the foundation pile 1 to avoid collision damage of the working ship to the foundation pile 1.

[0044] Step 4: Filling the internal material of the template: workers on the construction ship pump the sludge solidified soil into the two half-ring sand bags 4 through two mud pumps 6. Figures 3-4 After the two half-ring sand bags 4 are filled, the connection between the mud injection opening 402 and the mud injection pipeline 5 can be disconnected.

[0045] The construction method of the application combines geotextile and sludge solidified soil for offshore wind power foundation scour resistance, which has the following beneficial effects:

[0046] The jute fiber geotextile or kenaf fiber geotextile as the template and the internal filling of sludge solidified soil can effectively avoid the problems of large material loss, uneven material filling and uncontrollable protection range caused by the influence of complex seabed environment on the low early strength and large flowability of sludge solidified soil during pouring.

[0047] Since the half-ring jute fiber geotextile or kenaf fiber geotextile bag and the connecting device 407 are prefabricated in advance, the construction site only needs to be spliced and poured, and the workers on the construction ship can pump the sludge solidified soil into the jute fiber geotextile or kenaf fiber geotextile ring bag using the mud pump 6, which effectively improves the construction efficiency, reduces the construction scale, reduces the construction time, speeds up the construction speed, and greatly saves the construction cost to a certain extent.

[0048] The jute fiber geotextile or kenaf fiber geotextile is a degradable, high-strength, corrosion-resistant, seabed deformation adaptable, low-cost, light and green environmental protection material. As a template, it not only can protect the internal sludge solidified soil to a certain extent, but also has low cost and will not produce any harmful substances after degradation, which will not cause any impact on the seabed environment, so it does not need to be recycled later, and has good market application and promotion prospect.

[0049] The outer ring 403 of the closed semi-circular sand bag 4 has a width of 2 meters, which is sewn by single-layer jute fiber geotextile or single-layer jute fiber geotextile, and the remaining part is sewn by double-layer jute fiber geotextile or red jute fiber geotextile. Different thicknesses result in different degradation rates of the inner and outer rings of the closed sand bag. After the single-layer jute fiber geotextile or single-layer red jute fiber geotextile bag is quickly degraded, the internal silt stabilized soil can flow to the secondary scouring point, thereby achieving the effects of self-repairing, filling pores, preventing secondary scouring, and realizing the secondary scouring protection of the outer ring in the dynamic water environment of the seabed. The healing of the internal silt stabilized soil greatly enhances the design service life of the foundation pile.

[0050] The design of the "concave-convex combination" surface of the closed semi-circular sand bag 4 can effectively adjust the flow field pattern of the seabed, reduce the flow velocity around the foundation pile 1, and combine active protection with passive protection to reduce the influence of complex environmental factors on the seabed on the silt stabilized soil in the semi-circular jute fiber geotextile or red jute fiber geotextile and the foundation pile protection.

[0051] The above describes the embodiments of the present application in detail in combination with the drawings. The skilled person or construction worker can also make various changes without departing from the purpose of the present application.

Claims

1. A construction method for an offshore wind power foundation anti-scour silt solidification soil formwork, characterized in that: include: Step 1: Preliminary preparation: Use airborne laser detection technology to conduct topographic measurement of the seabed plane around the foundation pile (1) to check whether a scour pit (2) has formed on the seabed plane around the foundation pile (1); No scour pit is formed on the seabed (2): directly implement step 2; A scour pit (2) already exists on the seabed: a single layer of jute fiber geotextile or a single layer of kenaf fiber geotextile is sewn into a small sand bag (3) by an industrial sewing machine, silt solidification soil is pumped into the small sand bag (3) by a mud pump (6), and the scour pit (2) around the foundation pile (1) is filled with the small sand bag (3) filled with silt solidification soil, and the filling standard is that the area around the foundation pile (1) is flush with the seabed plane; Step 2: Template prefabrication: Sewing a single layer of jute fiber geotextile or a single layer of kenaf fiber geotextile into two identical closed semicircular ring sand bags (4) with an inner radius of 5 meters and an outer radius of 30 meters in advance in the factory by an industrial sewing machine, so as to facilitate direct application at the construction site later; the inner height of the closed semicircular ring sand bag (4) is 1 meter, and the outer height is 0 meter; a foundation pile through hole (401) with a length of 1 meter, a width of 0.5 meters, and a spacing of 1 meter is reserved in advance at a distance of 0.3 meters from the inner splicing surface of the closed semicircular ring sand bag (4) to reserve sufficient space for the installation of the later connection device (407), and at the same time, a mud injection port (402) is reserved on each closed semicircular ring sand bag (4); The outer ring (403) of the closed semi-circular ring sand bag (4) is 2 meters wide and is made of a single layer of jute fiber geotextile or a single layer of jute fiber geotextile, and the inner ring (404) is made of a double layer of jute fiber geotextile or a double layer of jute fiber geotextile. The surface of the closed semi-circular ring sand bag (4) is combined with a concave portion (405) and a convex portion (406), combining active protection with passive protection. The connecting device (407) is made of stainless steel and can be prefabricated in a factory in advance and can be directly installed after being transported to the construction site. In step 2, template prefabrication includes: Step 2.1: Lay out a single layer of jute fiber geotextile or a single layer of kenaf fiber geotextile flat and straight, and cut it according to the required size of the small sand bag (3); Step 2.2: Draw lines at each sewing location and sew using the overlock method; fill the small sandbag (3) with silt and solidify the soil, and then seal it with lead wire; Step 2.3: Lay the jute fiber geotextile or kenaf fiber geotextile flat and straight, and cut it according to the required size of the two semi-circular ring sand bags (4). At the same time, when cutting, a rectangular through hole should be reserved in advance at a distance of 0.3 meters from the inner splicing surface of the closed semi-circular ring sand bags (4); Step 2.4: The connecting device (407) is composed of two identical components. Both components are generally processed from stainless steel plates (4071). The bottom of the component is the stainless steel plate (4071), and the upper portion is evenly distributed with a hollow stainless steel body (4072) composed of stainless steel. The upper portion of the hollow stainless steel body (4072) is made into a rounded form. At the same time, a circular ring (4073) is reserved on the upper portion of the hollow stainless steel body (4072). After the template is spliced ​​at the construction site, a steel cable (4074) is tied. Step 2.5: Draw the lines at each sewing location and sew with the overlock method. At the same time, the four sides around the rectangular through hole reserved for the convenience of installing the later connection device (407) must be sewn with jute fiber geotextile or kenaf fiber geotextile; Step 3: Template splicing: Use two working surfaces AB to complete the splicing of the jute fiber geotextile template or the kenaf fiber geotextile template. Working surface A is operated by a full-rotation loader and a fixed-rod crane to lift the prefabricated connecting device (407) to the surrounding of the foundation pile (1); working surface B is responsible for workers on the construction ship to splice two semi-circular sand bags (4) around the foundation pile (1) through the connecting device (407), and at the same time, two sufficiently long mud injection pipes (5) are fixedly connected to the mud injection ports (402) on the two semi-circular sand bags (4), and then the template is allowed to sink freely in the seawater to the seabed plane by its own gravity; Step 4: Filling the internal material of the formwork: Workers on the construction ship use two mud pumps (6) to pump silt solidified soil into the two semi-circular sand bags (4). After the two semi-circular sand bags (4) are filled, the connection between the mud injection port (402) and the mud injection pipe (5) can be disconnected, and then the mud injection port (402) can be closed.

2. The construction method of the offshore wind power foundation anti-scour silt solidification soil formwork according to claim 1 is characterized in that: In step 1, if it is detected that there are protrusions on the seabed plane around the foundation pile (1), the protrusions should be cleaned.

3. The construction method of the offshore wind power foundation anti-scour silt solidification soil formwork according to claim 1 is characterized in that: In step 2.3, shrinkage is reserved during cutting, and a margin is left for the cutting size. At the same time, the mud injection port (402) adopts an inner-buckled pipe thread interface, which can be directly disconnected after pumping the silt solidified soil. Its special structure can ensure that seawater cannot be poured in.

4. The construction method of the offshore wind power foundation anti-scour silt solidification soil formwork according to claim 3 is characterized in that: In step 2.3, after the templates are spliced, the steel cables (4074) are tied by workers at the construction site.

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