Green construction method for offshore bridge island steel platform pile foundation
By using an independent mud and freshwater storage system and solid-liquid separation technology, the problems of high mud treatment costs and cumbersome freshwater transportation in the construction of steel platform pile foundations for isolated offshore bridges have been solved, achieving a balance between environmental protection and economy, and protecting the marine ecological environment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA CONSTRUCTION SIXTH ENGINEERING DIVISION CO LTD
- Filing Date
- 2026-03-20
- Publication Date
- 2026-07-21
Smart Images
Figure CN121897015B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of marine bridge construction technology, specifically a green construction method for pile foundations of isolated steel platforms for marine bridges. Background Technology
[0002] During the construction of the steel platform pile foundation for the offshore bridge, drilling operations generate a large amount of mud and drilling cuttings. At the same time, construction and living require a large amount of fresh water. Existing construction techniques have many shortcomings in terms of environmental protection and cost, making it difficult to meet the dual requirements of green construction and marine ecological protection.
[0003] Traditional drilling mud and cuttings treatment faces three major challenges: transportation, dumping, and discharge. Transportation costs are extremely high, off-site dumping poses unknown ecological risks, and direct discharge severely pollutes the operating area. Existing technologies primarily focus on preventing discharge into the sea. Conventionally, mud vessels are deployed to transport drilling mud to shore for processing, but this fails to fundamentally address the more complex environmental issue of "how to scientifically and beneficially return it to the ocean." Directly discharging raw drilling cuttings containing chemical additives, with small particles and unstable properties, into the sea causes suspension, sludge formation, and chemical pollution.
[0004] Meanwhile, conventional construction methods also require freshwater supply vessels for construction and domestic water use. Frequent freshwater transportation not only increases construction costs but also generates a large amount of exhaust emissions from ship voyages, further exacerbating the environmental burden. Summary of the Invention
[0005] To address the shortcomings of existing technologies, the present invention aims to provide a green construction method for the pile foundation of isolated steel platforms for offshore bridges. This method solves the problems of high costs and significant ecological risks associated with the existing construction of pile foundations for isolated steel platforms for offshore bridges, as well as the cumbersome freshwater transportation and high emissions, which fail to achieve a balance between environmental protection and economic efficiency.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: a green construction method for steel platform pile foundations for offshore bridges on isolated islands, comprising the following steps:
[0007] S1. Platform and storage system pre-set: After the isolated steel platform is erected, a mud and fresh water storage system containing water bladders and matching steel pipe piles is set up on the platform. In the initial state, the water bladders are empty and the steel pipe piles are filled with seawater.
[0008] S2. Transportation of construction materials and equipment: Transportation of fresh water, bentonite and related construction equipment required for construction;
[0009] S3. Equipment installation and resource reserves: Install and debug the equipment, prepare mud and fill the mud water bladder, fill the fresh water bladder, and simultaneously discharge the seawater from the steel pipe pile;
[0010] S4. Hole drilling, cleaning, and cuttings resource utilization: Drilling and replenishing mud for wall protection, cleaning the hole, separating the solid and liquid of the mud containing cuttings, recycling the mud, and bagging the cuttings to backfill the seabed around the pile foundation.
[0011] S5. Lowering the reinforcing cage, pouring concrete and replenishing mud: Lower the reinforcing cage and pour underwater concrete, collect the overflow mud, and replenish the mud according to the loss.
[0012] S6. Construction completion and harmless disposal of waste: After all pile foundation construction is completed, a flocculant is added to the mud storage area. After the water and soil separation meets the standards, the clean water is discharged into the sea, and the water bag and separated slag are placed on the seabed for harmless disposal.
[0013] Preferably, in step S1, in the mud and freshwater storage system, the mud storage area and the freshwater storage area are independent of each other, and steel pipe piles are installed around the outside of the water bladder. The steel pipe piles are used to support and protect the water bladder, and the height of the steel pipe piles is 40-60cm higher than the top of the water bladder.
[0014] Preferably, in step S2, the relevant construction equipment includes a mud separation system, a mud pump, a freshwater pump, and a mud preparation tank; freshwater is transported by a freshwater supply vessel, and bentonite and all construction equipment are transported centrally by transport barges, with the bentonite packaged in sealed containers.
[0015] Preferably, in step S3, the mud preparation involves mixing fresh water and bentonite and pumping the mixture into the mud storage area. The amount of mud stored in the mud storage area is equivalent to the amount of mud required for the construction of a single bridge pile foundation. Fresh water from the fresh water supply ship is pumped into the fresh water bladder, and the amount of fresh water stored therein meets the needs of a single batch of pile foundation construction and domestic water use. At the same time, seawater is discharged from the steel pipe pile to complete the fresh water reserve.
[0016] Preferably, in step S4, after the drilling machinery is debugged, drilling is started, and mud is continuously added during the drilling process to ensure good wall protection; after drilling to the designed depth, the hole is cleaned, and the mud carrying the drill cuttings is transported to the mud separation system for solid-liquid separation. The separated mud is returned to the pile foundation hole for recycling; the separated drill cuttings are bagged and sealed, and backfilled around the pile foundation to form the seabed according to the principle of uniformity and symmetry.
[0017] Preferably, in step S4, during the drilling process, the mud is continuously and uniformly supplied, and the supply speed matches the drilling speed. The hole is cleaned by replacing the mud.
[0018] Preferably, in step S4, when backfilling the drill cuttings, they are evenly and symmetrically distributed around the pile foundation, with a backfill thickness of 2-3 cm and a backfill range of 2-3 m around the pile foundation.
[0019] Preferably, in step S5, underwater concrete pouring is carried out using the tremie pipe method; when replenishing mud loss, fresh water is extracted and mixed with bentonite according to the initial mud configuration ratio to ensure that the performance of the replenished mud is consistent with the initial mud configuration.
[0020] Preferably, in step S6, the precipitant is a composite precipitant of polyaluminum chloride and polyacrylamide, with a mass ratio of 5 to 8:1, and the dosage is 0.5% to 1.0% of the slurry mass. After addition, the mixture is stirred evenly and then allowed to settle.
[0021] Preferably, in step S6, water quality testing is required before the water is discharged, and it can only be discharged after passing the test; the water bag is made of biodegradable rubber material, and its degradation cycle is consistent with that of high-strength biodegradable geotextile sandbags; the steel pipe pile is pulled out slowly to avoid damaging the water bag.
[0022] Compared with existing technologies, this invention has the following advantages: by using a mud separation system to separate the solid and liquid components of drilling cuttings mud, the mud is recycled for subsequent drilling operations, and the drilling cuttings are bagged and backfilled into the seabed around the pile foundation. After degradation, they form a seabed that alleviates seawater erosion. This not only avoids the high cost of transporting mud off-site, but also eliminates the pollution of the marine environment caused by the dumping or discharge of drilling cuttings, thus achieving the environmental protection goal of scientifically and beneficially returning the mud to the ocean.
[0023] By storing construction and domestic water through an independent freshwater storage system, and centrally transporting materials and equipment, the number of voyages of freshwater supply ships is reduced, ship exhaust emissions are lowered, and freshwater transportation costs are reduced. This solves the problems of cumbersome, costly, and polluting freshwater supply in conventional construction.
[0024] At the end of the construction, a composite precipitant is used to separate the mud and water. After the clean water meets the standards, it is discharged into the sea. The water tank and the separated slag are made of biodegradable materials. After being placed on the seabed, they degrade naturally without leaving any pollutants. The whole process meets the requirements of green construction, protects the marine ecological environment to the greatest extent, and avoids the ecological risks caused by improper waste disposal in existing technologies. Attached Figure Description
[0025] Figure 1 This is a flowchart of an embodiment of the present invention. Detailed Implementation
[0026] The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments.
[0027] like Figure 1 As shown in the figure, this invention proposes a green construction method for the pile foundation of a steel platform on an isolated island for a marine bridge, which includes the following steps:
[0028] S1. Platform and storage system pre-set: After the isolated steel platform is erected, a mud and fresh water storage system containing water bladders and matching steel pipe piles is set up on the platform. In the initial state, the water bladders are empty and the steel pipe piles are filled with seawater.
[0029] S2. Transportation of construction materials and equipment: Transportation of fresh water, bentonite and related construction equipment required for construction;
[0030] S3. Equipment installation and resource reserves: Install and debug the equipment, prepare mud and fill the mud water bladder, fill the fresh water bladder, and simultaneously discharge the seawater from the steel pipe pile;
[0031] S4. Hole drilling, cleaning, and cuttings resource utilization: Drilling and replenishing mud for wall protection, cleaning the hole, separating the solid and liquid of the mud containing cuttings, recycling the mud, and bagging the cuttings to backfill the seabed around the pile foundation.
[0032] S5. Lowering the reinforcing cage, pouring concrete and replenishing mud: Lower the reinforcing cage and pour underwater concrete, collect the overflow mud, and replenish the mud according to the loss.
[0033] S6. Construction completion and harmless disposal of waste: After all pile foundation construction is completed, a flocculant is added to the mud storage area. After the water and soil separation meets the standards, the clean water is discharged into the sea, and the water bag and separated slag are placed on the seabed for harmless disposal.
[0034] A mud separation system separates the solid and liquid components of drilling cuttings. The mud is recycled for subsequent drilling operations, while the cuttings are bagged and backfilled onto the seabed surrounding the pile foundation. After degradation, they form seabed that mitigates seawater erosion. This avoids the high costs of transporting mud externally and eliminates the pollution to the marine environment caused by dumping or discharging drilling cuttings, achieving a scientific and beneficial environmental goal of returning the cuttings to the ocean. An independent freshwater storage system stores construction and domestic water, centrally transports materials and equipment, reduces the number of voyages for freshwater supply vessels, lowers ship exhaust emissions, and reduces freshwater transportation costs, solving the problems of cumbersome, costly, and polluting freshwater supply in conventional construction. At the end of construction, a composite precipitant is used to separate the mud from the soil. The clean water meets standards and is discharged into the sea. The water bags and separated cuttings are made of biodegradable materials and degrade naturally on the seabed without residual pollutants. The entire process meets green construction requirements, maximizing the protection of the marine ecological environment and avoiding the ecological risks caused by improper waste disposal in existing technologies.
[0035] like Figure 1As shown, in step S1, in the mud and freshwater storage system, the mud storage area and the freshwater storage area are independent of each other. Steel pipe piles are installed around the outside of the water bladders to support and protect them, and the height of the steel pipe piles is 40-60cm higher than the top of the water bladders. After the isolated steel platform is erected, the mud storage system and the freshwater storage system are installed in the pre-designated mud storage area and freshwater storage area of the platform, respectively. The mud storage system includes biodegradable and environmentally friendly mud water bladders and matching steel pipe piles, with the height of the steel pipe piles 40-60cm higher than the top of the water bladders, preferably 50cm. The freshwater storage system includes biodegradable and environmentally friendly freshwater water bladders and matching steel pipe piles. Each steel pipe pile has an opening to connect with seawater, ensuring that seawater can smoothly enter and exit the steel pipe without affecting the structural safety of the steel pipe due to water pressure differences. The water bladders in each area are connected by horizontal steel pipes between the steel pipe piles.
[0036] The specific method is as follows: pipes are installed in the horizontal connecting steel pipes between the steel pipe piles to directly connect all the water bladders in the entire area to form a whole, ensuring that the water bladders are filled and the drainage process is synchronized, thereby improving the stability and coordination of the storage system; in the initial state, both the mud water bladders and the fresh water bladders are empty, and the inner cavity of the steel pipe piles of both types of storage systems is naturally filled with seawater, ensuring that the storage system and the platform structure are coordinated and stable, and meeting the subsequent storage and operation requirements.
[0037] like Figure 1 As shown, in step S2, the relevant construction equipment includes a mud separation system, mud pumps, freshwater pumps, and a mud preparation tank. Freshwater is transported by a freshwater supply vessel, while bentonite and all construction equipment are transported centrally by transport barges. The bentonite is packaged in sealed containers. One freshwater supply vessel is used to transport construction and domestic water, with a total volume of 250 m³. One transport barge is used to centrally transport 100 t of bentonite, one centrifugal mud separator, two mud pumps, two freshwater pumps, and one mud preparation tank (with a volume of 50 m³). During transportation, the bentonite is packaged in waterproof sealed bags to prevent moisture absorption and clumping.
[0038] like Figure 1As shown, in step S3, the mud preparation involves mixing fresh water and bentonite and pumping the mixture into the mud storage area. The amount of mud stored in the mud storage area is equivalent to the amount of mud required for the construction of a single bridge pile foundation. Fresh water from the fresh water supply ship is pumped into the fresh water bladder, and the amount of fresh water stored in it meets the needs of a single batch of pile foundation construction and domestic water use. At the same time, seawater is discharged from the steel pipe pile to complete the fresh water reserve. The mud separation system, mud pump, freshwater pump, and mud preparation tank were installed at the designated location on the platform. The pipelines were connected and tested to ensure normal equipment operation. During mud preparation, freshwater from the freshwater storage area was drawn and mixed with bentonite at a mass ratio of 100:8. The mixture was stirred at 180 r / min for 45 minutes using a mixing device to prepare qualified mud. The mud was then pumped into the mud storage area until the mud bladder was full. At this point, the seawater inside the steel pipe pile was squeezed out by the mud, and the mud storage volume was 600 m³, which is equivalent to the amount of mud required for the construction of a single bridge pile foundation. At the same time, freshwater from the freshwater supply ship was pumped into the freshwater storage area until the freshwater bladder was full. The seawater inside the steel pipe pile was discharged simultaneously. The freshwater storage volume met the construction and domestic water needs for 7 to 10 days for the construction of a single pile foundation.
[0039] like Figure 1 As shown, in step S4, after the drilling machinery is debugged, drilling begins. During drilling, mud is continuously added to ensure good wall protection. After drilling to the designed depth, the hole is cleaned, and the mud carrying drill cuttings is transported to a mud separation system for solid-liquid separation. The separated mud is returned to the pile foundation hole for recycling. The separated drill cuttings are bagged and sealed, and backfilled around the pile foundation to form the seabed according to the principle of uniformity and symmetry. The drilling machinery is arranged and drilling begins. During drilling, mud is added at a uniform speed, and the mud level is 1.5m above the sea level to ensure the wall protection effect. After drilling is completed, the mud is replaced and the hole is cleaned. After cleaning, a mud separation system is used for solid-liquid separation. The sand content of the separated mud is ≤2%, and it is recycled. The drill cuttings are bagged in high-strength biodegradable geotextile sandbags, each with a capacity of 40kg. After sealing, they are evenly backfilled around the pile foundation. The degradation period of the high-strength biodegradable geotextile sandbags is 6 months, and the degradation rate is not less than 80%.
[0040] like Figure 1 As shown, in step S4, during drilling, the drilling mud is continuously and uniformly supplied at a rate matched to the drilling speed. This continuous and uniform supply, combined with the requirement that the mud level be 1.5m above sea level, effectively protects the borehole wall, preventing collapse during offshore construction, ensuring borehole quality, and adapting to the complex offshore construction environment. The borehole is cleaned using a mud replacement method, which effectively removes sediment from the bottom of the hole, meeting the construction standards for subsequent underwater concrete pouring, further improving the pile foundation construction qualification rate, and laying the foundation for the pile foundation's bearing capacity.
[0041] like Figure 1As shown, in step S4, during drill cuttings backfilling, the cuttings are evenly and symmetrically distributed around the pile foundation, with a backfill thickness of 2-3 cm and a backfilling range of 2-3 m around the pile foundation. A drill cuttings backfill thickness of 2.5 m and a backfilling range of 2.5 m can form a uniform protective layer, avoiding uneven local stress, improving the stability of the seabed around the pile foundation, and indirectly enhancing the bearing capacity of the pile foundation. After the drill cuttings are bagged and sealed, they are backfilled without the need for external transportation or off-site dumping, completely solving the traditional problems of "transporting, throwing, and discharging" drill cuttings. This reduces transportation costs, avoids drilling cuttings polluting the sea area, and realizes the resource utilization of drill cuttings.
[0042] like Figure 1 As shown, in step S5, underwater concrete pouring is carried out using the tremie pipe method. This method is suitable for offshore underwater construction environments and avoids problems such as segregation and seawater inclusion during concrete pouring, ensuring concrete density and guaranteeing the quality of pile foundation pouring. When replenishing mud, fresh water is extracted and mixed with bentonite according to the initial mud preparation ratio to ensure that the performance of the replenished mud is consistent with the initial mud preparation. Replenishing mud according to the initial mud preparation ratio accurately ensures that the performance of the replenished mud is consistent with the initial mud, avoiding the impact of mud performance fluctuations on the subsequent borehole wall protection effect and eliminating construction hazards such as borehole wall collapse.
[0043] like Figure 1 As shown, in step S6, the precipitant used is a composite precipitant of polyaluminum chloride and polyacrylamide, with a mass ratio of 5-8:1. Using this composite precipitant, with a ratio of 5-8:1, provides better sedimentation than a single precipitant, enabling rapid and thorough separation of mud and soil, meeting the needs of efficient disposal at the end of offshore construction. The dosage is 0.5%-1.0% of the mud mass. After addition, it is stirred evenly and then allowed to settle. Controlling the dosage to 0.5%-1.0% of the mud mass ensures thorough separation of water and soil while avoiding excessive precipitant addition that would lead to waste and increased costs. It also prevents excessive precipitant residue from polluting the sea, aligning with green environmental protection requirements. Stirring evenly after addition and then allowing it to settle ensures sufficient contact between the precipitant and the mud, preventing incomplete local sedimentation and ensuring that the separated water meets the standards (meeting the Class II seawater quality standards), providing a guarantee for compliant discharge of clean water into the sea and preventing water pollution.
[0044] like Figure 1As shown, in step S6, water quality testing is required before the discharge of clean water. Discharge is only permitted after the test results are satisfactory. Pre-discharge water quality testing ensures strict control over the discharged water quality, guaranteeing that the clean water meets the Class II seawater quality standards, preventing marine pollution caused by the discharge of substandard clean water, and thoroughly implementing harmless disposal requirements, aligning with green environmental protection principles. The water bladder is made of biodegradable rubber, with a degradation cycle consistent with that of high-strength biodegradable geotextile sandbags. This allows for simultaneous natural degradation of the water bladder and drilling cuttings sandbags, leaving no residual pollutants and preventing long-term ecological damage from waste remaining in the sea area, achieving environmentally friendly disposal throughout the entire process. The steel pipe piles are slowly pulled out to avoid damaging the water bladder. This slow extraction method effectively prevents damage to the water bladder due to rapid extraction, ensuring that the water bladder and its internal separated soil are completely delivered to the seabed, preventing soil leakage and marine pollution, while also ensuring a smooth final disposal process and improving construction standardization.
[0045] The implementation principle of this application embodiment is as follows: using the steel platform of the isolated island of the offshore bridge as the working carrier, firstly, a mud / fresh water storage system with perforated steel pipe piles and biodegradable connected water bags is deployed, and construction materials and equipment are transported and installed; preliminary preparations are completed by preparing mud and storing fresh water; mud is used to protect the wall during drilling, and after cleaning the hole, mud and drill cuttings are separated (mud is recycled, and drill cuttings are bagged and backfilled to protect the piles); after pouring concrete, overflowing mud is collected and losses are replenished; after all pile foundations are completed, the remaining mud is treated with a precipitant, the clean water is discharged into the sea, and the waste is placed on the seabed for natural degradation, thus achieving green, efficient, and safe pile foundation construction.
[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A green construction method for pile foundations of isolated steel platforms for offshore bridges, characterized in that, It includes the following steps: S1. Platform and storage system setup: After the isolated steel platform is erected, a mud and fresh water storage system containing water bladders and matching steel pipe piles is set up on the platform. In the initial state, the water bladders are empty and the steel pipe piles are filled with seawater. In the mud and fresh water storage system, the mud storage area and the fresh water storage area are independent of each other. Steel pipe piles are set around the outside of the water bladders. The steel pipe piles are used to support and protect the water bladders, and the height of the steel pipe piles is 40-60cm higher than the top of the water bladders. S2. Transportation of construction materials and equipment: Transportation of fresh water, bentonite and related construction equipment required for construction; S3. Equipment installation and resource reserves: Install and debug the equipment, prepare mud and fill the mud water bladder, fill the fresh water bladder, and simultaneously discharge the seawater from the steel pipe pile; S4. Hole drilling, cleaning, and cuttings resource utilization: Drilling and replenishing mud for wall protection, cleaning the hole, separating the solid and liquid of the mud containing cuttings, recycling the mud, and bagging the cuttings to backfill the seabed around the pile foundation. S5. Lowering the reinforcing cage, pouring concrete and replenishing mud: Lower the reinforcing cage and pour underwater concrete, collect the overflow mud, and replenish the mud according to the loss. S6. Construction Completion and Harmless Disposal of Waste: After all pile foundation construction is completed, a precipitant is added to the mud storage area. The precipitant is a composite precipitant of polyaluminum chloride and polyacrylamide, with a mass ratio of 5 to 8:
1. The amount added is 0.5% to 1.0% of the mud mass. After addition, the mixture is stirred evenly and then allowed to settle. After the water and soil separation meets the standards, the clear water is discharged into the sea, and the water bag and separated slag are placed on the seabed for harmless disposal.
2. The green construction method for steel platform pile foundation of offshore bridges on isolated islands according to claim 1, characterized in that, In step S2, the relevant construction equipment includes a mud separation system, a mud pump, a fresh water pump, and a mud preparation tank; fresh water is transported by a fresh water supply vessel, and bentonite and all construction equipment are transported centrally by transport barges, with the bentonite being sealed in packaging.
3. The green construction method for steel platform pile foundations for offshore bridges on isolated islands according to claim 1, characterized in that, In step S3, the mud is prepared by mixing fresh water and bentonite and pumping it into the mud storage area. The amount of mud stored in the mud storage area is equivalent to the amount of mud required for the construction of a single bridge pile foundation. Fresh water in the fresh water supply ship is pumped into the fresh water bladder. The amount of fresh water stored in the bladder meets the construction and domestic water needs of a single batch of pile foundation construction. At the same time, the seawater in the steel pipe pile is discharged to complete the fresh water reserve.
4. The green construction method for steel platform pile foundation of offshore bridges on isolated islands according to claim 1, characterized in that, In step S4, after the drilling machinery is debugged, drilling is started. During the drilling process, mud is continuously added to ensure good wall protection. After drilling to the designed depth, the hole is cleaned and the mud carrying the drill cuttings is transported to the mud separation system for solid-liquid separation. The separated mud is returned to the pile foundation hole for recycling. The separated drill cuttings are bagged and sealed, and backfilled around the pile foundation to form the seabed according to the principle of uniformity and symmetry.
5. The green construction method for steel platform pile foundation of offshore bridges on isolated islands according to claim 4, characterized in that, In step S4, during the drilling process, the mud is continuously and uniformly supplied, and the supply speed is matched with the drilling speed. The hole cleaning is carried out by mud replacement method.
6. The green construction method for steel platform pile foundation of offshore bridges on isolated islands according to claim 5, characterized in that, In step S4, when backfilling the drill cuttings, they are evenly and symmetrically distributed around the pile foundation, with a backfill thickness of 50-80cm and a backfill range of 1-2m around the pile foundation.
7. The green construction method for steel platform pile foundations for offshore bridges on isolated islands according to claim 1, characterized in that, In step S5, underwater concrete is poured using the tremie pipe method; when replenishing mud loss, fresh water is extracted and mixed with bentonite according to the initial mud configuration ratio to ensure that the performance of the replenished mud is consistent with the initial mud configuration.
8. The green construction method for steel platform pile foundation of offshore bridges on isolated islands according to claim 1, characterized in that, In step S6, water quality testing is required before water discharge, and water can only be discharged after passing the test. The water bladder is made of biodegradable rubber, and its degradation cycle is consistent with that of high-strength biodegradable geotextile sandbags. The steel pipe piles are pulled out slowly to avoid damaging the water bladder.