A rigid skeleton-flexible filling synergistic scour prevention body and a construction method and application thereof

Abstract

The application relates to the technical field of underwater engineering protection, in particular to a rigid framework-flexible filling collaborative scour protection body and a construction method and application thereof. The rigid framework-flexible filling collaborative scour protection body is constructed by using a homologous silt-based solidified soil material system, has close interface combination, high integrity, outstanding scour resistance, can effectively block secondary scouring, is suitable for complex marine hydrodynamic environments, and can meet the actual needs of offshore wind power, cross-sea bridges and other marine engineering structure foundation scour protection and repair. Meanwhile, the preparation method and the construction method of the rigid framework-flexible filling collaborative scour protection body are controllable, feasible, the raw materials are widely sourced and solid waste resource utilization is realized, green low-carbon benefits are remarkable, and the method is suitable for large-scale engineering application.

Description

Technical Field

[0001] This application relates to the field of underwater engineering protection technology, and in particular to a rigid frame-flexible fill synergistic scour protection body and its construction method and application. Background Technology

[0002] Marine engineering structures, as core carriers for human development and utilization of marine resources, are directly related to energy supply, transportation, and economic development through their safe and stable operation. Key facilities such as offshore wind turbine foundations, cross-sea bridge piers, and port and wharf piles inevitably face the severe engineering challenge of localized scour during long-term exposure to the complex marine environment. The construction and operation of these structures significantly and continuously disturb the surrounding hydrodynamic environment, fundamentally altering the equilibrium state of the region's original natural flow field. Specifically, when water flows over solid structures, it triggers a series of complex hydrodynamic phenomena, including flow around the structure, sudden changes in velocity, vortex generation, and even turbulent diffusion. These changes drastically enhance the critical conditions for initiation and transport intensity of the seabed sediment, which is mainly composed of sediment, around the foundations of various types of structures, including monopiles, pile groups, and caissons. Ultimately, this leads to the formation and continuous development of localized scour pits around the foundations.

[0003] Localized scour is essentially a dynamic geological and geomorphological reshaping process, and its harm to marine engineering structures is both gradual and destructive. As the scour pit deepens and expands, the effective burial depth of the foundation decreases continuously, directly leading to a significant weakening of the foundation's lateral and vertical bearing capacity, and a sharp decline in the structural stability reserve. More seriously, non-uniform or excessive scour alters the dynamic response characteristics of the structural system, easily inducing uneven foundation settlement, structural tilting, and other defects. In extreme cases, it may even trigger structural resonance, fundamentally threatening the long-term safety and service life of the entire engineering structure. Under extreme sea conditions such as typhoons and storm surges, severe localized scour can directly cause foundation instability, leading to the overturning or collapse of the superstructure. This not only results in huge economic losses but may also lead to a chain of disasters such as energy supply disruptions and ecological damage. Therefore, developing efficient, reliable, green, and low-carbon scour prevention technologies has become a critical issue that urgently needs to be addressed in the field of marine engineering.

[0004] To address the threat of localized scour and ensure the safety of marine structures throughout their entire lifecycle, the engineering community has gradually developed and applied various active and passive scour prevention technologies. The core design concepts of these technologies can be summarized into two categories: one is to achieve energy dissipation and deceleration by setting up physical barriers, directly weakening the dynamic intensity of the scour flow; the other is to stabilize or reshape the seabed sediment, enhancing its resistance to initiation and transport, thereby suppressing scour at its source. Currently, commonly used scour protection methods in major projects such as offshore wind power and cross-sea bridges mainly include riprap protection, geotextile concrete protection, and soil stabilization protection, but all of these methods face significant technical bottlenecks in practical applications.

[0005] Rockfill protection, due to its simple construction and strong adaptability, has become the most widely used traditional protection technology. Its principle is to form a protective layer by dumping rocks into the erosion area to resist the erosion of the seabed by water flow. However, the rockfill body is a granular accumulation structure with numerous voids between the rocks. Water flow can easily penetrate these voids, creating localized turbulence and triggering secondary erosion, leading to the failure of the protective layer. To compensate for this deficiency, cemented rockfill technology has emerged, which involves casting cement-based cementitious materials into the rockfill body to bind the granular rocks into a monolithic structure. However, this improved technology still has significant drawbacks. The rocks and cement-based cementitious materials are dissimilar materials with poor interfacial compatibility and weak bonding strength. Under repeated wave and water flow, interfacial cracks easily form, leading to overall structural failure. The mining and transportation of rocks are energy-intensive and costly, and large-scale quarrying can severely damage the terrestrial ecological environment, failing to meet ecological protection requirements. Furthermore, the high carbon emission intensity of cement production contradicts the current green and low-carbon engineering construction concept and is difficult to adapt to the development needs under dual-carbon goals.

[0006] Solidified soil protection technology, as a waste resource utilization technology, corely utilizes dredged silt or local seabed soil mixed with a solidifying agent for solidification, followed by pouring or dumping to form a protective structure. This achieves waste reduction and resource recovery, resulting in significant environmental benefits. Existing technologies use solidified soil pouring to form the foundation protection structure of underwater structures, providing a reference for the engineering application of this technology. However, existing single solidified soil protection systems still have key technological shortcomings. On the one hand, the erosion resistance of the solidified soil pouring body is limited, with its critical erosion velocity typically not exceeding 3 m / s, making it difficult to withstand the erosion effects of strong water flow areas. On the other hand, single solidified soil structures lack rigid framework support, resulting in insufficient impact resistance and deformation resistance of the overall structure. Under the combined action of strong water flow and waves, it is prone to overall failure, limiting its application range in complex marine environments.

[0007] To address the aforementioned technical shortcomings, there is an urgent need to improve existing technologies. Summary of the Invention

[0008] In view of this, this application provides a rigid-frame-flexible-fill synergistic scour protection body, its construction method, and its application. This rigid-frame-flexible-fill synergistic scour protection body is constructed using a homogeneous silt-based solidified soil material system, exhibiting tight interfacial bonding, strong integrity, and outstanding scour resistance. It effectively blocks secondary scouring, is suitable for complex marine hydrodynamic environments, and can meet the practical needs of scour protection and repair for the foundations of marine engineering structures such as offshore wind power and cross-sea bridges. Furthermore, the preparation and construction methods of the rigid-frame-flexible-fill synergistic scour protection body provided in this application are process-controllable and feasible, with widely available raw materials that achieve solid waste resource utilization, resulting in significant green and low-carbon benefits, making it suitable for large-scale engineering applications.

[0009] In the first aspect, this application discloses a rigid skeleton-flexible filler synergistic erosion control body, including the following technical solution: A rigid skeleton-flexible filler synergistic erosion control body includes a rigid skeleton layer and a flexible filler layer; The rigid skeleton layer consists of precast multi-scale high-strength solidified soil blocks stacked in the scour pit according to the design gradation. Solidified soil blocks of different sizes fill each other to form a multi-point support main load-bearing structure. The precast multi-scale high-strength solidified soil blocks include large-scale blocks with a side length of 500~800mm, medium-scale blocks with a side length of 300~500mm, and small-scale blocks with a side length of 100~300mm. The mass ratio of the large-scale blocks, medium-scale blocks, and small-scale blocks is 5~7:2~3:1~2. The flexible filling layer is a large-flow underwater non-dispersible solidified soil that fills the block gaps of the rigid skeleton layer and the irregular area around the scour pit. The prefabricated multi-scale high-strength solidified soil block and the large-flow underwater non-dispersible solidified soil are prepared using the same silt-based solidified soil material system. After solidification, the prefabricated multi-scale high-strength solidified soil block and the large-flow underwater non-dispersible solidified soil form a continuous interface transition zone through chemical bonding. The width of the interface transition zone is 50~200μm, and the interface bond strength is ≥0.8MPa. The overall erosion resistance of the anti-erosion body is ≥5m / s.

[0010] Preferably, the method for preparing the prefabricated multi-scale high-strength solidified soil block includes the following steps: Dry sludge is mixed with solid waste-based solidifying agent and then dry-mixed to obtain dry-mixed material; Water is added to the dry mixture and stirred to obtain a plastic mixture; The plastic mixture is loaded into a mold and vibrated in layers to obtain a shaped blank; The molded blanks are subjected to static curing and standard curing in sequence to obtain prefabricated multi-scale high-strength solidified soil blocks.

[0011] Preferably, the mass ratio of the solid waste-based solidifying agent, dry sludge, and water is 3~4:6~8:4~6.

[0012] Preferably, the moisture content of the dried sludge is 0-15%.

[0013] Preferably, the dry mixing speed is 60~80 r / min and the time is 20~30 min.

[0014] Preferably, the stirring speed is 80~100 r / min and the time is 50~80 min.

[0015] Preferably, the frequency of the layered vibration is 50~60Hz and the time is 30~60s.

[0016] Preferably, the static curing temperature is 15~25℃, the humidity is 80~100%, and the curing time is 20~28h.

[0017] Preferably, the standard curing temperature is 18~22℃, the humidity is 95~100%, and the time is 20~28h.

[0018] Preferably, the preparation method of the solid waste-based solidifying agent includes the following steps: Granulated blast furnace slag powder, steel slag powder, furnace slag powder and desulfurized gypsum are mixed and dry premixed to obtain premixed dry material; The activator and early strength agent are added to the premixed dry material and stirred to obtain a solid waste-based solidifying agent.

[0019] Preferably, the mass ratio of the granulated blast furnace slag powder, steel slag powder, furnace slag powder, desulfurized gypsum, activator and early strength agent is 50~70:10~20:10~20:5~15:2~5:0.5~2.

[0020] Preferably, the specific surface area of ​​the granulated blast furnace slag powder is 400~600 m². 2 / kg, vitreous content is 90%~100%, and water content is 0~1.0%.

[0021] Preferably, the specific surface area of ​​the steel slag powder is 350~500 m². 2 / kg, with a free calcium oxide content of 1~3%.

[0022] Preferably, the specific surface area of ​​the slag powder is 300~450m². 2 / kg, loss on ignition is 1~5%.

[0023] Preferably, the desulfurized gypsum has a water content of 0.1-2.0% and a calcium sulfate dihydrate content of 90%-100%.

[0024] Preferably, the activator is selected from one or both of water glass or sodium metasilicate.

[0025] Preferably, the dry material premixing is carried out under stirring conditions, with a rotation speed of 40~60 r / min and a time of 3~5 min.

[0026] Preferably, the stirring speed is 70~90 r / min and the time is 5~8 min.

[0027] Preferably, the method for preparing the high-flow-state underwater non-dispersible solidified soil includes the following steps: Dry sludge, underwater non-dispersible solidifying agent and flocculation are mixed and then dry-mixed to obtain dry-mixed material; Water is added to the dry-mixed material and stirred to obtain a large-flow underwater non-dispersible solidified soil.

[0028] Preferably, the mass ratio of the underwater non-dispersible solidifying agent, dry sludge, water and flocculant is (10~18):(30~40):(50~60):(0.5~1.5).

[0029] Preferably, the moisture content of the dried sludge is 0-15%.

[0030] Preferably, the dry mixing speed is 60~80 r / min and the time is 10~15 min.

[0031] Preferably, the stirring speed is 80~100 r / min and the time is 30~40 min.

[0032] Preferably, the flocculant is selected from one or two of polyacrylamide and polyaluminum chloride.

[0033] Preferably, the preparation method of the underwater non-dispersible curing agent includes the following steps: Granulated blast furnace slag powder, steel slag powder, fly ash and desulfurization gypsum are mixed and dry premixed to obtain premixed dry material; An activator and a suspension stabilizer are added to the premixed dry material and stirred to obtain a special underwater non-dispersible curing agent. The mass ratio of the granulated blast furnace slag powder, steel slag powder, fly ash, desulfurized gypsum, activator and suspension stabilizer is 50~65:10~20:15~25:5~10:1~3:1~3.

[0034] Preferably, the specific surface area of ​​the granulated blast furnace slag powder is 400~600 m². 2 / kg, vitreous content is 90%~100%, and water content is 0~1.0%.

[0035] Preferably, the specific surface area of ​​the steel slag powder is 350~500 m². 2 / kg, with a free calcium oxide content of 1~3%.

[0036] Preferably, the specific surface area of ​​the fly ash is 300~450 m². 2 / kg, loss on ignition is 1~5%.

[0037] Preferably, the desulfurized gypsum has a water content of 0.1-2.0% and a calcium sulfate dihydrate content of 90%-100%.

[0038] Preferably, the activator is selected from one or two of water glass and sodium metasilicate.

[0039] Preferably, the suspension stabilizer is selected from one or two of hydroxypropyl methylcellulose and sodium carboxymethyl cellulose.

[0040] Preferably, the dry material premixing speed is 40~60 r / min and the time is 3~5 min.

[0041] Preferably, the stirring speed is 70~90 r / min and the time is 5~8 min.

[0042] Secondly, this application discloses a construction method for the rigid skeleton-flexible filler synergistic erosion control body described in the aforementioned scheme, including the following steps: Precast multi-scale high-strength solidified soil blocks and high-flow underwater non-dispersible solidified soil are available for use. The precast multi-scale high-strength solidified soil blocks were directionally dumped into the scour pit using the conduit method to construct a rigid skeleton layer; The high-flow underwater non-dispersible solidified soil is pumped into the block gaps and irregular areas of the rigid skeleton layer and scour pits to form a flexible filling layer. The static setting process solidifies the non-dispersible solidified soil in the high-flow-rate underwater environment, allowing it to form a continuous interface transition zone with the precast solidified soil blocks through chemical bonding between materials of the same origin, thus forming an integral erosion-resistant body. The precast multi-scale high-strength solidified soil blocks are placed at a height of 1-3m from the bottom of the scour pit, and the placement speed is controlled at 0.5-1.5m / s. 3 / min; The pumping velocity of the high-flow-rate underwater non-dispersible solidified soil is controlled at 0.2~0.5m. 3 The filling height is continuously monitored during the pumping process, and the filling liquid level is always 0.5~1.0m higher than the pumping pipe outlet.

[0043] Thirdly, this application discloses the application of the rigid frame-flexible fill synergistic scour protection body described in the aforementioned scheme in scour protection of offshore wind power pile foundations, scour protection of cross-sea bridge pier foundations, suspended protection of submarine pipelines, scour protection of artificial island revetments, port and wharf foundation protection, or scour protection of riverbank slopes.

[0044] The rigid-frame-flexible-filler synergistic scour protection body, its construction method, and application provided in this application achieve synergistic force sharing between the rigid frame and the flexible filler, avoiding problems such as weak interface bonding, insufficient scour resistance, high carbon emissions, and susceptibility to secondary scouring in existing scour protection technologies. Therefore, compared with existing technologies, the scour protection body provided in this application has the characteristics of strong integrity, excellent scour resistance, and good structural stability, and can resist erosion in complex hydrodynamic environments for a long time. In addition, the scour protection body provided in this application has controllable preparation and construction processes, a high degree of raw material resource utilization, and wide applicability, possessing both practical value and market prospects, and providing an efficient and green solution for marine engineering and riverbank protection. Detailed Implementation

[0045] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the solutions in the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific implementation methods described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0046] In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operating state, specifically the directions in the design; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "including" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish a numerical order.

[0047] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0048] In this application, "at least one" means one or more, and "more than one" means two or more. "One or more", "at least one of the following", or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0049] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0050] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0051] In the first aspect, this application discloses a rigid skeleton-flexible filler synergistic erosion control body, including the following technical solution: A rigid skeleton-flexible filler synergistic erosion control body includes a rigid skeleton layer and a flexible filler layer; The rigid skeleton layer consists of precast multi-scale high-strength solidified soil blocks stacked in the scour pit according to the design gradation. Solidified soil blocks of different sizes fill each other to form a multi-point support main load-bearing structure. The precast multi-scale high-strength solidified soil blocks include large-scale blocks with a side length of 500~800mm, medium-scale blocks with a side length of 300~500mm, and small-scale blocks with a side length of 100~300mm. The mass ratio of the large-scale blocks, medium-scale blocks, and small-scale blocks is 5~7:2~3:1~2. The flexible filling layer is a large-flow underwater non-dispersible solidified soil that fills the block gaps of the rigid skeleton layer and the irregular area around the scour pit. The prefabricated multi-scale high-strength solidified soil block and the large-flow underwater non-dispersible solidified soil are prepared using the same silt-based solidified soil material system. After solidification, the prefabricated multi-scale high-strength solidified soil block and the large-flow underwater non-dispersible solidified soil form a continuous interface transition zone through chemical bonding. The width of the interface transition zone is 50~200μm, and the interface bond strength is ≥0.8MPa. The overall erosion resistance of the anti-erosion body is ≥5m / s.

[0052] In this application, the rigid skeleton layer serves as the main load-bearing structure of the erosion control body. Through the graded stacking of multi-scale solidified soil blocks, a dense and stable support system is formed, directly resisting 60% to 70% of the water flow impact force and providing core erosion resistance for the erosion control body. The flexible filling layer, with its high fluidity, fills the gaps and irregular areas of the skeleton layer, completely blocking the water flow channel and avoiding secondary erosion. At the same time, it forms an integral whole with the rigid skeleton layer through chemical bonding of homologous materials, solving the technical bottleneck of weak interfaces between heterologous materials. The two work together to achieve integrated "load-bearing and sealing" protection.

[0053] In some embodiments, the method for preparing the prefabricated multi-scale high-strength solidified soil blocks includes the following steps: mixing dry sludge with a solid waste-based solidifying agent and performing dry mixing treatment to obtain a dry-mixed mixture; adding water to the dry-mixed mixture and performing stirring treatment to obtain a plastic mixture; loading the plastic mixture into a mold and performing layered vibration to obtain a molded blank; and sequentially performing static curing and standard curing on the molded blank to obtain prefabricated multi-scale high-strength solidified soil blocks.

[0054] In some embodiments, the mass ratio of the solid waste-based solidifying agent, dry sludge, and water is 3~4:6~8:4~6, for example, it can be 3:6:4, 3.5:7:5, 4:8:6, or any two of the above values. When the mass ratio of the three components is within the above range, the strength and density of the solidified soil blocks can be ensured, avoiding both insufficient solidifying agent dosage leading to low strength and excessive dosage leading to cost waste. At the same time, it adapts to the plasticity of the dry sludge, ensuring the molding performance of the mixture.

[0055] In some embodiments, the moisture content of the dried sludge is 0-15%, for example, it can be any two values ​​between 0%, 5%, 10%, 15% or higher. When the moisture content of the dried sludge is within the above range, it can ensure uniform mixing with the curing agent, avoid excessive moisture content leading to bleeding and segregation of the mixture, or excessive moisture content leading to difficulty in mixing and high internal porosity, thus ensuring the structural integrity and mechanical properties of the solidified soil blocks.

[0056] In some embodiments, the dry mixing speed is 60-80 r / min, for example, it can be any two values ​​between 60 r / min, 70 r / min, 80 r / min or above; the time is 20-30 min, for example, it can be any two values ​​between 20 min, 25 min, 30 min or above. This parameter combination can achieve sufficient premixing of dry sludge and solidifying agent, so that the solidifying agent uniformly coats the sludge particles, laying the foundation for the subsequent hydration reaction and avoiding localized enrichment or deficiency of solidifying agent.

[0057] In some embodiments, the stirring speed is 80-100 r / min, for example, it can be any two values ​​between 80 r / min, 90 r / min, 100 r / min or more; the time is 50-80 min, for example, it can be any two values ​​between 50 min, 65 min, 80 min or more. High speed and long stirring time can ensure deep integration of water and dry mixture, promote the full hydration reaction of curing agent, improve the uniformity of plastic mixture, and reduce internal defects.

[0058] In some embodiments, the frequency of the layered vibration is 50-60 Hz, for example, it can be any two values ​​between 50 Hz, 55 Hz, 60 Hz or higher; the time is 30-60 s, for example, it can be any two values ​​between 30 s, 45 s, 60 s or higher. These vibration parameters can effectively remove air bubbles from the plastic mixture, compact the mixture, avoid defects such as pores and honeycomb inside the molded blank, ensure the density of the block, and improve its compressive strength and impact resistance.

[0059] In some embodiments, the static curing temperature is 15~25℃, for example, it can be any two values ​​between 15℃, 20℃, 25℃ or above; the humidity is 80~100%, for example, it can be any two values ​​between 80%, 90%, 100% or above; the curing time is 20~28h, for example, it can be any two values ​​between 20h, 24h, 28h or above. Static curing can provide a stable hydration environment for the green body, avoid early water loss and cracking, promote the initial formation of strength, and lay the foundation for subsequent standard curing.

[0060] In some embodiments, the standard curing temperature is 18~22℃, for example, it can be any two values ​​between 18℃, 20℃, 22℃ or higher; the humidity is 95~100%, for example, it can be any two values ​​between 95%, 98%, 100% or higher; and the time is 20~28h, for example, it can be any two values ​​between 20h, 24h, 28h or higher. Standard curing conditions ensure that the curing agent's hydration reaction is sufficient and uniform, allowing the block strength to steadily increase, ultimately meeting design requirements and guaranteeing its load-bearing capacity as a skeleton layer.

[0061] In some embodiments, the preparation method of the solid waste-based solidifying agent includes the following steps: mixing granulated blast furnace slag powder, steel slag powder, furnace slag powder and desulfurization gypsum, performing dry material premixing to obtain premixed dry material; adding an activator and an early strength agent to the premixed dry material, and performing stirring treatment to obtain the solid waste-based solidifying agent.

[0062] In some embodiments, the mass ratio of the granulated blast furnace slag powder, steel slag powder, furnace slag powder, desulfurized gypsum, activator, and early-strength agent is 50~70:10~20:10~20:5~15:2~5:0.5~2, for example, it can be 50:10:10:5:2:0.5, 60:15:15:10:3:1, 70:20:20:15:5:2, or any two of the above values. This ratio achieves high activity and low cost of the curing agent through the synergistic effect of industrial waste residue, the activator can activate the potential hydration activity of the waste residue, and the early-strength agent accelerates the strength development, meeting the construction schedule requirements.

[0063] In some embodiments, the specific surface area of ​​the granulated blast furnace slag powder is 400~600 m². 2 / kg, for example, it can be 400m 2 / kg, 500m 2 / kg, 600m 2 The specific surface area and high glass content are within the range of any two values ​​between 90% and 100%, for example, between any two values ​​between 90%, 95%, 100%, or above; the moisture content is 0% to 1.0%, for example, between any two values ​​between 0%, 0.5%, 1.0%, or above. High specific surface area and high glass content ensure sufficient reactivity of the slag powder, while low moisture content avoids affecting the storage stability and hydration effect of the curing agent.

[0064] In some embodiments, the specific surface area of ​​the steel slag powder is 350~500 m². 2 / kg, for example, can be 350m 2 / kg, 420m 2 / kg, 500m 2 / kg or above, within the range of any two values; free calcium oxide content is 1~3%, for example, it can be 1%, 2%, 3% or above, within the range of any two values. A suitable specific surface area ensures the reaction rate of the steel slag powder, and a low free calcium oxide content avoids volume expansion and cracking after solidification, thus improving the structural stability of the solidified soil blocks.

[0065] In some embodiments, the specific surface area of ​​the slag powder is 300~450 m². 2 / kg, for example, can be 300m 2 / kg, 380m 2 / kg, 450m 2 / kg or a range between any two values; loss on ignition is 1~5%, for example, it can be 1%, 3%, 5% or a range between any two values. A reasonable specific surface area and low loss on ignition ensure that the slag powder can effectively participate in the hydration reaction, improve the bonding performance of the curing agent, and avoid the curing effect being affected by excessive impurities.

[0066] In some embodiments, the moisture content of the desulfurized gypsum is 0.1-2.0%, for example, it can be within the range of any two values ​​between 0.1%, 1.0%, 2.0%, or higher; the calcium sulfate dihydrate content is 90%-100%, for example, it can be within the range of any two values ​​between 90%, 95%, 100%, or higher. High-purity calcium sulfate dihydrate can react with the hydration products of waste residue to form ettringite, enhancing the strength of the solidified body, while the low moisture content avoids gypsum clumping, which affects the uniformity of mixing.

[0067] In some embodiments, the activator is selected from one or both of water glass and sodium metasilicate. Both water glass and sodium metasilicate can effectively activate the potential activity of industrial waste residue, promote the hydration reaction process, and improve the early and late strength of the solidifying agent. They are also widely available and low in cost, making them suitable for the design concept of solid waste-based solidifying agents.

[0068] In some embodiments, the dry material premixing is carried out under stirring conditions, with a rotation speed of 40-60 r / min, for example, any two values ​​between 40 r / min, 50 r / min, 60 r / min, or higher; and a time of 3-5 min, for example, any two values ​​between 3 min, 4 min, 5 min, or higher. Low-speed, long-time premixing ensures uniform mixing of all waste residue components, avoids localized concentration differences, and lays the foundation for the uniform dispersion of subsequent functional agents.

[0069] In some embodiments, the stirring speed is 70-90 r / min, for example, it can be any two values ​​between 70 r / min, 80 r / min, 90 r / min or above; the time is 5-8 min, for example, it can be any two values ​​between 5 min, 6.5 min, 8 min or above. These stirring parameters enable the activator, early-strength agent and premixed dry material to be fully integrated, ensuring uniform distribution of functional agents and giving full play to their activation and early-strength effects.

[0070] In some embodiments, the preparation method of the high-flow-state underwater non-dispersible solidified soil includes the following steps: mixing dry sludge, underwater non-dispersible solidifying agent and flocculant, and performing dry mixing treatment to obtain a dry-mixed mixture; adding water to the dry-mixed mixture and performing stirring treatment to obtain high-flow-state underwater non-dispersible solidified soil.

[0071] In some embodiments, the mass ratio of the underwater non-dispersible solidifying agent, dried sludge, water, and flocculant is (10~18):(30~40):(50~60):(0.5~1.5), for example, it can be 10:30:50:0.5, 14:35:55:1.0, 18:40:60:1.5, or any two of the above values. This ratio can balance the high fluidity and underwater stability of the solidified soil, and the flocculant effectively prevents underwater segregation and loss, ensuring the filling effect and the quality of the interface bonding.

[0072] In some embodiments, the moisture content of the dried sludge is 0-15%, for example, it can be any two values ​​between 0%, 8%, 15%, or higher. This is consistent with the moisture content requirement for dried sludge used in precast blocks, ensuring material compatibility and mixing uniformity, and avoiding fluctuations in curing effect due to differences in moisture content.

[0073] In some embodiments, the dry mixing speed is 60-80 r / min, for example, it can be any two values ​​between 60 r / min, 70 r / min, 80 r / min or above; the time is 10-15 min, for example, it can be any two values ​​between 10 min, 12 min, 15 min or above. Dry mixing allows the curing agent, flocculant, and dry sludge to be fully premixed, ensuring uniform distribution of the functional agent after subsequent water addition and mixing, and avoiding localized failure.

[0074] In some embodiments, the stirring speed is 80-100 r / min, for example, it can be any two values ​​between 80 r / min, 90 r / min, 100 r / min or more; the time is 30-40 min, for example, it can be any two values ​​between 30 min, 35 min, 40 min or more. Thorough stirring allows water and the dry mixture to deeply blend, forming a fluid slurry, while simultaneously promoting the hydration reaction of the curing agent, ensuring underwater non-dispersibility and curing strength.

[0075] In some embodiments, the flocculant is selected from one or both of polyacrylamide and polyaluminum chloride. Both polyacrylamide and polyaluminum chloride have excellent flocculation properties, effectively adsorbing particles in the slurry, preventing cement slurry loss during underwater pouring, ensuring the density and strength of the solidified soil, and adapting to the requirements of underwater construction environments.

[0076] In some embodiments, the preparation method of the underwater non-dispersible curing agent includes the following steps: mixing granulated blast furnace slag powder, steel slag powder, fly ash and desulfurized gypsum, and performing dry material premixing to obtain premixed dry material; adding an activator and a suspension stabilizer to the premixed dry material and performing stirring treatment to obtain the underwater non-dispersible curing agent.

[0077] In some embodiments, the mass ratio of the granulated blast furnace slag powder, steel slag powder, fly ash, desulfurized gypsum, activator, and suspension stabilizer is 50~65:10~20:15~25:5~10:1~3:1~3, for example, it can be 50:10:15:5:1:1, 58:15:20:8:2:2, 65:20:25:10:3:3, or any two of the above values. This ratio optimizes the flowability and water retention of the curing agent through the addition of fly ash, while the suspension stabilizer enhances the underwater stability of the slurry and prevents segregation.

[0078] In some embodiments, the performance parameters of the granulated blast furnace slag powder, steel slag powder, and desulfurized gypsum are consistent with the requirements of the corresponding raw materials in the solid waste-based solidifying agent, ensuring the stability of material performance and synergistic effect.

[0079] In some embodiments, the specific surface area of ​​the fly ash is 300~450 m². 2 / kg, for example, can be 300m 2 / kg, 380m 2 / kg, 450m 2 / kg or a range between any two values; loss on ignition is 1~5%, for example, it can be a range between any two values ​​of 1%, 3%, 5% or higher. High specific surface area and low loss on ignition ensure that fly ash can participate in the hydration reaction to generate products with cementing properties, while improving the fluidity and water retention of the slurry.

[0080] In some embodiments, the suspension stabilizer is selected from one or both of hydroxypropyl methylcellulose and sodium carboxymethyl cellulose. Hydroxypropyl methylcellulose and sodium carboxymethyl cellulose have excellent thickening and suspending effects, which can significantly improve the viscosity and stability of the solidified soil slurry, prevent the separation of aggregate and slurry during underwater pouring, and ensure the filling density and interfacial bonding quality.

[0081] In some embodiments, the dry material premixing speed is 40~60 r / min and the time is 3~5 min; the stirring speed is 70~90 r / min and the time is 5~8 min, which is consistent with the stirring parameters for the preparation of solid waste-based solidifying agent, to ensure that the components are mixed evenly and to give full play to the synergistic effect.

[0082] Secondly, this application discloses a construction method for the rigid skeleton-flexible filler synergistic erosion control body described in the aforementioned scheme, including the following steps: Precast multi-scale high-strength solidified soil blocks and high-flow-rate underwater non-dispersible solidified soil are provided for later use. The precast multi-scale high-strength solidified soil blocks are directionally dumped into the scour pit using a tremie pipe method to construct a rigid skeleton layer. The high-flow-rate underwater non-dispersible solidified soil is pumped into the gaps between the blocks of the rigid skeleton layer and the irregular areas of the scour pit to form a flexible filling layer. The high-flow-rate underwater non-dispersible solidified soil is allowed to stand to solidify, so that it forms a continuous interface transition zone with the precast solidified soil blocks through chemical bonding between homologous materials, forming an integral scour protection body.

[0083] In this application, the combined construction process of tremie dredging and pumping filling can adapt to complex underwater environments, ensure accurate stacking of the skeleton layer and dense and full filling layer, and has strong controllability and high efficiency in the construction process, making it suitable for large-scale engineering applications.

[0084] In some embodiments, the placement height of the prefabricated multi-scale high-strength solidified soil blocks is controlled within the range of 1 to 3 meters from the bottom of the scour pit, for example, it can be any two values ​​between 1 meter, 2 meters, 3 meters, or more; the placement speed is controlled at 0.5 to 1.5 meters per second. 3 / min, for example, can be 0.5m 3 / min, 1.0m 3 / min, 1.5m 3 / min or any two of the above values. A reasonable filling height avoids excessive block accumulation leading to collapse, and an appropriate filling speed ensures that the blocks are evenly stacked according to their gradation, forming a stable skeleton structure and avoiding local gaps or insufficient compaction.

[0085] In some embodiments, the pumping velocity of the high-flow-rate underwater non-dispersible solidified soil is controlled to be 0.2~0.5m. 3 / min, for example, can be 0.2m 3 / min, 0.35m 3 / min, 0.5m 3 The pumping speed should be within the range of any two values ​​above / min; the filling height should be continuously monitored during pumping, and the filling material level should always be 0.5~1.0m higher than the pumping pipe outlet, for example, it can be 0.5m, 0.8m, 1.0m or any two values ​​above. Low-speed pumping avoids displacement of the skeleton layer or segregation of the filling material due to excessive flow rate. The filling material level being higher than the pumping pipe outlet can prevent air from being drawn into the pipe, ensuring continuous and dense filling and avoiding the formation of air bubbles or unfilled areas in the gaps.

[0086] Thirdly, this application discloses the application of the rigid frame-flexible fill synergistic scour protection body described in the aforementioned scheme in scour protection of offshore wind power pile foundations, scour protection of cross-sea bridge pier foundations, suspended protection of submarine pipelines, scour protection of artificial island revetments, port and wharf foundation protection, or scour protection of riverbank slopes.

[0087] With its excellent scour resistance, integrity, and green and low-carbon characteristics, this anti-scour body can adapt to various complex hydrodynamic environments such as oceans and riverbanks, effectively solve the scour problem of foundations of different types of structures, provide reliable protection for the long-term safety of engineering structures, and has broad application prospects.

[0088] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0089] Prefabricated multi-scale high-strength solidified soil blocks, solid waste-based solidifying agents, high-flow-state underwater non-dispersible solidified soil, and underwater non-dispersible special solidifying agents are prepared according to the preparation methods of specific implementation embodiments. Example 1

[0090] Project Overview: An offshore wind farm, with a water depth of 15m and a single pile foundation diameter of 6m, has formed a scour pit with a depth of 4m and a diameter of 8m around the pile foundation. The technology of this invention is used for scour protection.

[0091] Material proportions: First solidified soil: 18 parts solid waste-based solidifying agent (including 70 parts granulated blast furnace slag powder, 15 parts steel slag powder, 5 parts furnace slag powder, 10 parts desulfurized gypsum, 3 parts activator (sodium silicate), 2 parts early strength agent (sodium sulfate), 35 parts dry silt (taken from dredged silt from nearby waterways), 25 parts water, with a compressive strength of 7 MPa after 28 days of standard curing.

[0092] Second solidified soil: 15 parts of underwater non-dispersible solidifying agent (including 60 parts of granulated blast furnace slag powder, 15 parts of steel slag powder, 15 parts of fly ash, 10 parts of desulfurized gypsum, 2 parts of activator (calcium oxide), and 1 part of suspension stabilizer (bentonite), 35 parts of dry sludge (same as the sludge used for precast blocks), 55 parts of water, 1 part of flocculant (hydroxymethylpropyl cellulose, viscosity 50000mPa·s), slump spread 650mm, underwater casting loss 4%, 28-day compressive strength 3.4MPa.

[0093] Construction steps: Step 1: Precast blocks with a mass ratio of large-scale blocks, medium-scale blocks, and small-scale blocks of 6:2.5:1.5, and use them after curing for 7 days.

[0094] Step 2: Use the tremie pipe method for backfilling, controlling the backfilling height at 2m and the backfilling speed at 1.0m / s. 3 / min, first throw large blocks, then medium blocks, and finally small blocks to fill the gaps.

[0095] Step 3: Fill with flexible material using a pumping method, with a pumping pressure of 0.5 MPa and a pumping flow rate of 0.3 m / s. 3 / min, the pumping pipe outlet is buried 0.8m below the material surface, and pumping is carried out continuously for 2.5 hours until the gap is completely filled.

[0096] Step 4: After 7 days of static curing, conduct testing.

[0097] Effect detection: Core sampling after curing: the width of the interface transition zone is about 120μm, and the bond strength is 0.8MPa.

[0098] Water tank test: After continuous flushing at a simulated flow rate of 5.2 m / s for 24 hours in the laboratory, the surface remained intact and the overall structure was intact.

[0099] Carbon footprint accounting: Based on the whole life cycle assessment, the carbon footprint is reduced by 76% compared to the traditional rubble and cement solutions. Example 2

[0100] Project Overview: A bridge pier of a cross-sea bridge is located in water with a depth of 20m. The pier foundation measures 10m x 8m, and localized scour pits with a depth of 3.5m have formed around it. The technology of this invention is used for protection.

[0101] Material proportions: First solidified soil (block): 16 parts solid waste-based solidifying agent (including 65 parts granulated blast furnace slag powder, 15 parts steel slag powder, 5 parts furnace slag powder, 15 parts desulfurized gypsum, 2 parts activator (sodium metasilicate), 1.5 parts early strength agent (sodium sulfate), 38 parts dry silt (taken from dredged silt from nearby waterways), 24 parts water, with a compressive strength of 6.2 MPa after 28 days of standard curing.

[0102] Second solidified soil (fill): 12 parts of underwater non-dispersible solidifying agent (including: 60 parts of granulated blast furnace slag powder, 15 parts of steel slag powder, 14 parts of fly ash, 12 parts of desulfurized gypsum, 2 parts of activator (calcium oxide), and 1 part of suspension stabilizer (bentonite), 35 parts of dry sludge (same as the sludge used for precast blocks), 58 parts of water, 1 part of flocculant (hydroxymethylpropyl cellulose, viscosity 50000 mPa·s), slump spread 670 mm, underwater casting loss 4.8%, 28-day compressive strength 3.1 MPa.

[0103] Construction steps: Step 1: Precast blocks with a mass ratio of large-scale blocks, medium-scale blocks, and small-scale blocks of 6:3:2, and use them after curing for 7 days.

[0104] Step 2: Use the tremie method for backfilling, controlling the backfilling height at 2.5m and the backfilling speed at 0.8m / s. 3 / min, first throw large blocks, then medium blocks, and finally small blocks to fill the gaps.

[0105] Step 3: Fill the flexible material using a pumping method, with a pumping pressure of 0.6 MPa and a pumping flow rate of 0.4 m / s. 3 / min, the pumping pipe outlet is buried 0.5m below the material surface, and pumping is carried out continuously for 2.5 hours until the gap is completely filled.

[0106] Step 4: After 7 days of static curing, conduct testing.

[0107] Effect detection: Core sampling after curing: the width of the interface transition zone is about 110 μm, and the bond strength is 0.9 MPa.

[0108] Water tank test: After continuous flushing at a simulated flow rate of 5.5 m / s for 24 hours in the laboratory, the surface remained intact and the overall structure was intact.

[0109] Carbon footprint accounting: Based on the whole life cycle assessment, the carbon footprint is reduced by 72% compared to the traditional rubble-laying + cement solution. Comparative Example 1

[0110] Solution: Use natural boulders (particle size 200~500mm) for backfilling, and then pour cement-based binder (42.5 grade ordinary Portland cement: water: sand = 1:0.5:2), with cement content calculated at 20% of the volume of boulders.

[0111] Test results: The width of the interface transition zone is approximately 500 μm, and the interface adhesion strength is 0.3 MPa. After being scoured at a flow rate of 5.5 m / s for 24 hours, the anti-scour structure experienced localized scouring and subsidence, leading to fracture and a weakening of its anti-scour effect. Comparative Example 2

[0112] Solution: Use only the flexible filler from Example 1, cast integrally, without a rigid skeleton layer.

[0113] Test results: Erosion resistance: 2.8 m / s; After scouring at a flow rate of 5.0 m / s for 24 hours, scour pits appeared around the pile foundation. Comparative Example 3

[0114] Solution: Use natural boulders (same as Comparative Example 1) as a rigid framework and use the flexible filler of Example 1 as filler.

[0115] Test results: The width of the interface transition zone is approximately 380 μm, and the interface adhesion strength is 0.5 MPa. After flushing at a flow rate of 5.0 m / s for 24 hours, the interface separated.

[0116] The technical solutions provided by the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A rigid frame-flexible filler synergistic erosion control body, characterized in that, It includes a rigid skeleton layer and a flexible filler layer; The rigid skeleton layer consists of precast multi-scale high-strength solidified soil blocks stacked in the scour pit according to the design gradation. Solidified soil blocks of different sizes fill each other to form a multi-point support main load-bearing structure. The precast multi-scale high-strength solidified soil blocks include large-scale blocks with a side length of 500~800mm, medium-scale blocks with a side length of 300~500mm, and small-scale blocks with a side length of 100~300mm. The mass ratio of the large-scale blocks, medium-scale blocks, and small-scale blocks is 5~7:2~3:1~2. The flexible filling layer is a large-flow underwater non-dispersible solidified soil that fills the block gaps of the rigid skeleton layer and the irregular areas around the scour pit. The prefabricated multi-scale high-strength solidified soil block and the large-flow underwater non-dispersible solidified soil are prepared using the same silt-based solidified soil material system. After solidification, the prefabricated multi-scale high-strength solidified soil block and the large-flow underwater non-dispersible solidified soil form a continuous interface transition zone through chemical bonding. The width of the interface transition zone is 50~200μm, and the interface bond strength is ≥0.8MPa. The overall erosion resistance of the anti-erosion body is ≥5m / s.

2. The rigid skeleton-flexible filler synergistic erosion control body according to claim 1, characterized in that, The method for preparing the prefabricated multi-scale high-strength solidified soil block includes the following steps: Dry sludge is mixed with solid waste-based solidifying agent and then dry-mixed to obtain dry-mixed material; Water is added to the dry mixture and stirred to obtain a plastic mixture; The plastic mixture is loaded into a mold and vibrated in layers to obtain a shaped blank; The molded blanks are subjected to static curing and standard curing in sequence to obtain prefabricated multi-scale high-strength solidified soil blocks.

3. The rigid skeleton-flexible filler synergistic erosion control body according to claim 2, characterized in that, The mass ratio of the solid waste-based solidifying agent, dry sludge, and water is 3~4:6~8:4~6; and / or The moisture content of the dried sludge is 0-15%; and / or The dry mixing process is carried out at a speed of 60-80 r / min for a time of 20-30 min; and / or The stirring speed is 80~100 r / min, and the time is 50~80 min; and / or The frequency of the layered vibration is 50-60 Hz, and the time is 30-60 s; and / or The static curing temperature is 15~25℃, the humidity is 80~100%, and the curing time is 20~28h; and / or The standard curing temperature is 18~22℃, the humidity is 95~100%, and the time is 20~28h.

4. The rigid skeleton-flexible filler synergistic erosion control body according to claim 2 or 3, characterized in that, The preparation method of the solid waste-based solidifying agent includes the following steps: Granulated blast furnace slag powder, steel slag powder, furnace slag powder and desulfurized gypsum are mixed and dry premixed to obtain premixed dry material; The activator and early strength agent are added to the premixed dry material and stirred to obtain a solid waste-based solidifying agent.

5. The rigid skeleton-flexible filler synergistic erosion control body according to claim 4, characterized in that, The mass ratio of the granulated blast furnace slag powder, steel slag powder, furnace slag powder, desulfurization gypsum, activator, and early strength agent is 50~70:10~20:10~20:5~15:2~5:0.5~2; and / or The specific surface area of the granulated blast furnace slag powder is 400-600 m 2 / kg, the glass content is 90%-100%, and the water content is 0-1.0%; and / or The specific surface area of the steel slag powder is 350-500 m 2 / kg, and the free calcium oxide content is 1-3%; and / or The specific surface area of the slag powder is 300-450 m 2 / kg, and the loss on ignition is 1-5%; and / or The desulfurized gypsum has a moisture content of 0.1-2.0% and a calcium sulfate dihydrate content of 90%-100%; and / or The activator is selected from one or both of water glass and sodium metasilicate; and / or The dry material premixing is carried out under stirring conditions, with a rotation speed of 40~60 r / min and a time of 3~5 min; and / or The stirring speed is 70~90 r / min and the time is 5~8 min.

6. The rigid skeleton-flexible filler synergistic erosion control body according to claim 1, characterized in that, The method for preparing the large-flow underwater non-dispersible solidified soil includes the following steps: Dry sludge, underwater non-dispersible solidifying agent and flocculant are mixed and dry-mixed to obtain dry-mixed material; Water is added to the dry-mixed material and stirred to obtain a large-flow underwater non-dispersible solidified soil.

7. The rigid skeleton-flexible filler synergistic erosion control body according to claim 6, characterized in that, The mass ratio of the underwater non-dispersible solidifying agent, dried sludge, water, and flocculant is (10~18):(30~40):(50~60):(0.5~1.5); and / or The moisture content of the dried sludge is 0-15%; and / or The dry mixing process is carried out at a speed of 60-80 r / min for a time of 10-15 min; and / or The stirring speed is 80~100 r / min, and the time is 30~40 min; and / or The flocculant is selected from one or two of polyacrylamide, polyaluminum chloride, and cellulose.

8. The rigid skeleton-flexible filler synergistic erosion control body according to claim 6 or 7, characterized in that, The preparation method of the underwater non-dispersible curing agent includes the following steps: Granulated blast furnace slag powder, steel slag powder, fly ash and desulfurization gypsum are mixed and dry premixed to obtain premixed dry material; An activator and a suspension stabilizer are added to the premixed dry material and stirred to obtain a special underwater non-dispersible curing agent. The mass ratio of the granulated blast furnace slag powder, steel slag powder, fly ash, desulfurization gypsum, activator, and suspension stabilizer is 50~65:10~20:15~25:5~10:1~3:1~3; and / or The granulated blast furnace slag powder has a specific surface area of 400-600 m 2 / kg, a glass content of 90-100%, and a water content of 0-1.0%; and / or The specific surface area of ​​the steel slag powder is 350~500 m². 2 / kg, free calcium oxide content 1~3%; and / or The specific surface area of ​​the fly ash is 300~450m². 2 / kg, loss on ignition is 1~5%; and / or The desulfurized gypsum has a moisture content of 0.1-2.0% and a calcium sulfate dihydrate content of 90%-100%; and / or The activator is selected from one or two of water glass and sodium metasilicate; and / or The suspension stabilizer is selected from one or two of hydroxypropyl methylcellulose and sodium carboxymethyl cellulose; and / or The dry material premixing speed is 40~60 r / min, and the time is 3~5 min; and / or The stirring speed is 70~90 r / min and the time is 5~8 min.

9. A construction method for a rigid frame-flexible filler synergistic erosion control body as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Precast multi-scale high-strength solidified soil blocks and high-flow underwater non-dispersible solidified soil are available for use. The precast multi-scale high-strength solidified soil blocks were directionally dumped into the scour pit using the conduit method to construct a rigid skeleton layer; The high-flow underwater non-dispersible solidified soil is pumped into the block gaps and irregular areas of the rigid skeleton layer and scour pits to form a flexible filling layer. The static setting process solidifies the non-dispersible solidified soil in the high-flow-rate underwater environment, allowing it to form a continuous interface transition zone with the precast solidified soil blocks through chemical bonding between materials of the same origin, thus forming an integral erosion-resistant body. The precast multi-scale high-strength solidified soil blocks are placed at a height of 1-3m from the bottom of the scour pit, and the placement speed is controlled at 0.5-1.5m / s. 3 / min; The pumping velocity of the high-flow-rate underwater non-dispersible solidified soil is controlled at 0.2~0.5m. 3 The filling height is continuously monitored during the pumping process, and the filling liquid level is always 0.5~1.0m higher than the pumping pipe outlet.

10. The application of the rigid frame-flexible fill synergistic scour protection body as described in any one of claims 1 to 8 in scour protection of offshore wind power pile foundations, scour protection of cross-sea bridge pier foundations, suspended protection of submarine pipelines, scour protection of artificial island revetments, port and wharf foundation protection, or riverbank slope protection.