Cylindrical caisson structure for ultra-large water depth tower and construction method

Abstract

The invention relates to the technical field of bridge foundation construction, in particular to a tower drum type caisson structure for an ultra-large water depth and a construction method. Comprising a cylinder base, and the cylinder base comprises a bottom plate supported on a lower steel pipe pile, an annular side plate fixed to the bottom plate and a top plate fixed to the side plate; a hole is formed in the circle center of the top plate, and the top plate, the side plates and the bottom plate form a hollow prefabricated reinforced concrete structure. The cylinder body comprises an inner cylinder positioned in the cylinder seat and an outer cylinder positioned outside the cylinder seat; the inner cylinder and the cylinder base are coaxial, and the two axial ends of the inner cylinder are fixed to the bottom plate and the top plate respectively. The outer barrel is of a barrel-shaped structure which is poured at the upper end of the inner barrel in a staged mode on a construction site and extends out of the barrel base. The caisson structure in the ultra-large water depth environment and the construction method have the advantages of being high in construction precision, good in economical efficiency, good in adaptability, high in construction efficiency and high in safety.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of bridge foundation construction, in particular to a super-large water-depth tower-cylinder type caisson structure and a construction method. BACKGROUND

[0002] In the field of marine engineering construction, with the increasing demand of human beings for the development and utilization of marine resources, various marine infrastructure constructions such as bridges, ports and offshore wind power projects are increasing, and are expanding to deeper waters. When engineering construction is carried out in super-large water-depth areas, many technical challenges are faced, especially in terms of caisson structures and construction methods.

[0003] For example, a Chinese invention patent with the patent number CN101148890B, named "Bridge caisson composite pile foundation and reverse construction method thereof", introduces a caisson construction method. After the bridge caisson is sunk to the bed, pile construction is carried out inside the caisson, and the upper part of the pile is connected with the bottom of the caisson to form a caisson composite pile foundation. This method forms a composite foundation by arranging steel pipe piles on the caisson bottom plate. After the land prefabricated caisson is launched, it is floated and sunk to the dredged seabed and leveled and positioned, personnel enter the caisson interior from the top of the caisson, steel pipe piles are driven through the preformed holes in the caisson bottom plate, and at the same time, the upper structure is constructed. After the steel pipe piles are completed, the caisson bottom plate and the steel pipe piles are connected by pouring concrete, and the load is borne by the caisson bottom plate and the pile. This foundation construction technology is suitable for the construction of bridge foundations in deep water, thick soft soil foundation.

[0004] However, this method is only suitable for construction in shallow water areas, and for super-large depth water areas, it is not possible to carry out steel pipe pile construction after the caisson is sunk. This caisson structure has some limitations when applied in deep water areas. The structure design of the cylinder seat and tower column is not optimized, resulting in insufficient overall strength and stability, making it difficult to adapt to the complex hydrogeological conditions of super-large water depth. In the construction process, this caisson sinking method is complex to operate and has complicated process conversion, not only low construction efficiency, but also prone to problems such as inaccurate positioning, sinking difficulty, etc., which seriously affects the engineering progress and quality, increases the engineering cost and risk.

[0005] In addition, the construction environment in deep water areas has very high requirements for foundation stability. The previous foundation treatment methods, such as simply using steel pipe piles or gravel foundations, cannot guarantee long-term stability and bearing capacity under super-large water depth conditions, and are easily affected by factors such as water flow scouring and foundation settlement, thereby affecting the safety of the entire caisson structure. Moreover, there is a risk of pollution to the surrounding water environment during the construction process, which does not meet the requirements of modern marine engineering construction for environmental protection. SUMMARY

[0006] The purpose of the present application is to solve the problems in the background art, and provide a tower cylinder type caisson structure for super deep water and a construction method.

[0007] The technical solution of the present application is as follows: a tower cylinder type caisson structure for super deep water, comprising: a cylinder base, which comprises a bottom plate supported on a lower steel pipe pile, an annular side plate fixed on the bottom plate, and a top plate fixed on the side plate; the top plate is provided with a hole at the center, and the side plate and the bottom plate form a hollow prefabricated reinforced concrete structure; a cylinder body, which comprises an inner cylinder located in the cylinder base and an outer cylinder located outside the cylinder base; the inner cylinder is coaxial with the cylinder base, and the two axial ends of the inner cylinder are fixed on the bottom plate and the top plate respectively; the outer cylinder is a cylindrical structure poured on the upper end of the inner cylinder in stages at the construction site, and extends to the outside of the cylinder base.

[0008] According to the tower cylinder type caisson structure for super deep water provided by the present application, the cylinder base is provided with an inner wall and a plurality of caisson inner ribs arranged in a circumferential direction; the inner wall is a cylindrical structure arranged coaxially with the cylinder base; the caisson inner rib is a vertical support rib with its upper end and lower end fixedly connected to the top plate and the bottom plate respectively, and one side of the caisson inner rib is connected to the inner side of the side plate, and the other side extends radially to be connected to the outer side of the inner wall.

[0009] According to the tower cylinder type caisson structure for super deep water provided by the present application, the cylinder base is loaded with ballast during the sinking construction process.

[0010] The present application also relates to a construction method for the tower cylinder type caisson structure for super deep water, comprising: flattening and reinforcing the water bottom at the caisson construction position; preparing the cylinder base and the inner cylinder at a shore-side prefabrication plant; building a trestle at the caisson construction position; transporting the prepared cylinder base to the trestle; positioning the cylinder base; adjusting the draft depth and the levelness of the cylinder base, pouring the outer cylinder on the top part of the inner cylinder in stages, and until the bottom plate of the cylinder base is completely sunk to the water bottom; throwing and backfilling the water bottom around the cylinder base with stones.

[0011] According to the construction method provided by the present application, the method for flattening and reinforcing the water bottom at the caisson construction position comprises: excavating the water bottom at the caisson construction position to form a foundation trench; inserting and driving a plurality of steel pipe piles in the foundation trench; throwing and filling broken stones in the foundation trench to form a broken stone layer; tamping the broken stone layer, and performing surface scraping treatment on the tamped broken stone layer.

[0012] According to the construction method provided in the application, the method for building the trestle at the caisson construction position comprises: building a semicircular trestle at the caisson construction position, and the trestle is arranged coaxially with the caisson outside the caisson in the construction position.

[0013] According to the construction method provided in the application, the method for adjusting the draft and the levelness of the cylinder seat comprises: placing temporary loads in the cylinder seat, and adjusting the draft and the levelness of the cylinder seat by the weight and the placement position of the temporary loads.

[0014] According to the construction method provided in the application, the method for pouring the outer cylinder in the top stage of the inner cylinder comprises: after the adjustment of the draft and the levelness of the cylinder seat is completed, building a formwork on the top of the inner cylinder to pour the first part of the outer cylinder; after the first part is completely stable, building a formwork on the top of the first part to pour the second part of the outer cylinder; after the bottom plate of the cylinder seat is completely sunk to the bottom of the water, building a formwork on the top of the second part to pour the third part of the outer cylinder, and the pouring construction of the outer cylinder is completed.

[0015] According to the construction method provided in the application, after the pouring construction of the second part of the outer cylinder is completed, permanent ballast is poured into the cylinder seat until the bottom plate of the cylinder seat is completely sunk to the bottom of the water.

[0016] According to the construction method provided in the application, the method for backfilling the bottom of the water around the cylinder seat with riprapping comprises: dividing the designed riprapping area of the bottom of the water around the cylinder seat into multiple squares, and throwing riprapping to each square according to a zigzag route to form a filter layer on the riprapping layer; and throwing anti-scour riprapping on the filter layer.

[0017] The caisson cylinder seat of the application adopts a prefabricated reinforced concrete structure, and the hollow design reduces the self-weight. Meanwhile, through the combination of the bottom plate, the annular side plate and the top plate, a stable support system is formed, which can effectively disperse the load and adapt to high pressure and complex hydraulic conditions under the environment of super large water depth. The prefabrication of the inner cylinder of the cylinder body ensures the precision and quality, and the on-site staged pouring of the outer cylinder allows flexible adjustment of the height according to the actual water depth, avoiding the difficulty of one-time lifting or pouring of the traditional caisson, and is particularly suitable for scenarios where the water depth exceeds 50 meters. The cylinder seat and the inner cylinder are prefabricated in a shore-side prefabrication plant, reducing the on-site construction time and cost, improving the quality control, and only requiring staged pouring of the outer cylinder on site, reducing the demand for large lifting equipment and saving resources. This modular design also facilitates transportation and installation, shortens the overall construction period, and is suitable for large-scale offshore engineering construction. The cylinder seat is supported on steel pipe piles, providing a reliable foundation, and the hollow structure reduces the influence of buoyancy and enhances the overturning resistance. The fixed connection between the inner cylinder and the cylinder seat ensures the overall rigidity, and the gradual pouring of the outer cylinder allows the structure to gradually adapt to load changes, reducing the risk of cracking and prolonging the service life. Meanwhile, the gradual pouring of the outer cylinder can be coordinated with the ballast to slowly sink the caisson, reducing the difficulty of caisson sinking construction, and improving the construction efficiency and precision. 2、The inner wall of the application is arranged coaxially with the cylinder base as a cylindrical structure, and forms an internal support network together with the inner ribs of the caisson, significantly improving the bending and shear resistance of the cylinder base; in an environment with ultra-deep water, the water pressure and wave load are large, and the inner wall and the rib plate can effectively resist lateral pressure to prevent deformation or damage of the cylinder base; the upper and lower ends of the inner ribs are fixed with the top plate and the bottom plate respectively, and one side is connected with the side plate and the other side is connected with the inner wall; this design uniformly transmits the load from the side plate to the bottom plate and the inner wall, reduces stress concentration, and avoids local fatigue damage; this is crucial for caisson structures that bear long-term dynamic loads (such as wind and waves); the arrangement of the inner wall and the rib plate divides the internal space of the cylinder base, facilitating the placement of ballast or equipment during construction, and providing convenience for subsequent maintenance; this structure also enhances the overall stability and reduces the risk of tilting caused by uneven loads during sinking; 3、The use of ballast in the application allows construction personnel to precisely control the draft and levelness of the cylinder base by adjusting the weight and position, ensuring smooth sinking of the cylinder base to the designed position; this is particularly important in an environment with ultra-deep water, as water flow and waves can cause structural drift or oscillation; ballast increases the sinking force of the cylinder base, avoiding the structure from floating or losing control due to excessive buoyancy, reducing the risk of accidents; at the same time, ballast can be used as a temporary stabilizing measure to resist external disturbances during construction, ensuring construction accuracy; ballast usually uses inexpensive materials (such as sand or concrete), with low cost and easy adjustment; this method reduces the dependence on complex mechanical equipment (such as large ballast systems), simplifies the construction process, and is suitable for various site conditions; 4、The application also relates to a construction method, the method of the application covers the complete process from water bottom leveling to riprap backfilling, ensuring the coherence and coordination of construction; the caisson construction method of the application improves overall efficiency, especially suitable for complex projects in ultra-deep water environments; by combining prefabrication and site pouring, the uncertainty of site operation is reduced; water bottom leveling and trestle construction provide a stable foundation for caisson positioning and sinking, reducing construction errors; the method also focuses on environmental adaptability, reducing interference with marine ecology; the caisson construction method of the application is clear in steps and easy to operate, allowing parallel work (such as prefabrication and trestle construction at the same time), shortening the construction period; suitable for batch construction of multiple caisson structures, with good repeatability and scalability; 5、The application forms a foundation layer with high strength and high flatness through excavating a foundation trench, driving a steel pipe pile, throwing and filling broken stones, and tamping, ensuring the close contact of the caisson bottom plate with the water bottom and preventing uneven settlement; in an ultra-large water depth environment, the water bottom geology may be weak or uneven, and the method effectively improves the foundation bearing capacity; the steel pipe pile provides deep support, and the broken stone layer acts as a buffer layer to disperse the load; surface scraping treatment further optimizes the flatness, reduces the gap under the bottom plate, and avoids base erosion caused by water flow; this prolongs the service life of the structure and reduces the maintenance requirements; the leveling construction steps of the application are detailed and quantifiable, facilitating monitoring and quality control; the driving of the steel pipe pile increases the integrity of the foundation, is suitable for high water pressure and dynamic load conditions, and improves the engineering safety; 6、The semicircular trestle designed by the application is arranged around the caisson and coaxial with the caisson, creating a full-range working channel for material transportation, equipment installation, and personnel operation; in an ultra-large water depth environment, the trestle reduces the risk of water operation and improves construction efficiency; the trestle rationally utilizes the construction area and avoids interference with other operations; its stable structure can withstand the influence of wind and waves, providing reliable support for caisson positioning and pouring; at the same time, the trestle can serve as a temporary observation point for real-time monitoring of the sinking process; the shape and size of the trestle can be adjusted according to the size of the caisson and the water depth, making it suitable for various engineering scenarios; the construction materials are usually recyclable, reducing costs and environmental impact; 7、The application can fine-tune the floating state and attitude of the cylinder seat by the weight and placement position of temporary loads (such as sand bags or counterweights), ensuring its levelness and designed draft depth; this is crucial in ultra-large water depths, as slight tilting can cause structural instability or installation failure; this adjustment method does not require complex sensors or control systems, relying on simple physical principles to achieve, reducing equipment investment and operational complexity; temporary loads are easy to obtain and adjust, adapting to site changes and shortening adjustment time; precise control of draft depth and levelness avoids cylinder seat collision or deviation with the foundation during the sinking process, reducing the risk of structural damage; at the same time, this method allows for correction during construction, improving fault tolerance; 8、The application allows the outer cylinder concrete to gradually consolidate and bear by pouring in stages, avoiding the impact of excessive load caused by one-time pouring; this ensures the slow sinking of the cylinder seat under control, preventing stress concentration caused by the sudden bottom plate touching the bottom; waiting for the concrete to stabilize after each stage of pouring reduces the risk of cracking and deformation, ensuring the integrity and durability of the outer cylinder; the template erection and pouring process is easy to monitor, ensuring dimensional accuracy and appearance quality; the pouring method of the application is synchronized with the sinking of the cylinder seat, and the increase in the height of the outer cylinder gradually increases the sinking force, allowing the bottom plate to finally contact the water bottom smoothly; this dynamic construction method optimizes resource utilization and reduces waiting time; 9. The permanent ballast in this application provides continuous sinking force, ensuring that the base plate of the cylinder sinks completely to the bottom of the water and enhancing anti-buoyancy capability; in extremely deep water, the permanent ballast counteracts water pressure and buoyancy, preventing the structure from floating or shifting; the casting of the permanent ballast is carried out simultaneously during the casting of the outer cylinder, optimizing the construction sequence and avoiding delays caused by separate operations; the ballast is integrated with the structure, improving overall stiffness and stability; the permanent ballast typically uses low-cost materials but provides long-term protection, reducing maintenance requirements; this method also avoids the removal and disposal of temporary ballast, saving resources and time; 10. This application, by dividing the rock into squares and placing it along a zigzag path, forms a uniform filter layer and an anti-erosion riprap layer, preventing water flow from eroding the foundation and reducing the risk of base erosion. In extremely deep water environments where water flow velocity may be high, this method provides reliable protection. The square division and zigzag path ensure the uniformity of riprap distribution, avoiding voids or accumulation, and improving the density and stability of the backfill layer. The filter layer allows water flow permeability, reduces hydrostatic pressure, and prevents the loss of fine particles. This riprap backfilling method is simple and easy to implement, and is suitable for various underwater conditions. The anti-erosion riprap layer enhances the overall structure's impact resistance and extends its service life. The construction process can be mechanized, improving efficiency and reducing labor costs.

[0018] This application provides a caisson structure and construction method for ultra-deep water environments, which has the advantages of high construction precision, good economy, good adaptability, high construction efficiency and strong safety, and has great potential for promotion. Attached Figure Description

[0019] Figure 1 : A schematic diagram of the caisson structure in this application; Figure 2 : A schematic cross-sectional view of the caisson structure in this application; Figure 3 This application includes a schematic diagram of steel pipe pile driving. Figure 4 : A schematic diagram of the caisson structure being towed in this application; Figure 5 : A schematic diagram showing the relative positional relationship between the trestle bridge and the caisson structure in this application; Figure 6 : A schematic diagram of the caisson structure sinking in this application; Wherein: 1—Cylinder base; 1.1—Bottom plate; 1.2—Side plate; 1.3—Top plate; 1.4—Inner wall; 1.5—Inner rib of caisson; 1.6—Ballast material; 2—cylinder body; 2.1—inner cylinder; 2.2—outer cylinder; 3—Trestling bridge; 4—Steel pipe pile; 5—Impact riprap; 6—Filter layer; 7—Gravel layer; 8—Bubble launching device; 9—Gas pipeline. Detailed Implementation

[0020] The embodiments of this application are described in detail below, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0021] In the description of this application, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0023] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0024] This application relates to a tower-type caisson structure and construction method for ultra-deep water (e.g., over 50 meters), such as... Figures 1 to 6 As shown, the structure mainly includes a cylindrical base 1 and a cylindrical body 2. The cylindrical base 1 is a hollow precast reinforced concrete structure, including a bottom plate 1.1, annular side plates 1.2, and a top plate 1.3. The bottom plate 1.1 is supported on pre-constructed steel pipe piles 4 below. The top plate 1.3 has a hole at its center, which, together with the side plates 1.2 and the bottom plate 1.1, forms a closed cavity. The top plate 1.3 has a tapered structure that is smaller at the top and larger at the bottom, which further enhances the structural strength of the entire cylindrical base 1. A pull ring is installed on the top plate 1.3, which can serve as a hoisting point for the entire cylindrical base 1.

[0025] The cylindrical body 2 includes an inner cylinder 2.1 and an outer cylinder 2.2. The inner cylinder 2.1 is a prefabricated structure located inside the cylinder base 1, with its two axial ends fixedly connected to the bottom plate 1.1 and the top plate 1.3, respectively, and arranged coaxially with the cylinder base 1. The outer cylinder 2.2 is a cylindrical concrete structure cast in stages and sections at the construction site above the inner cylinder 2.1. It extends upward from the holes in the top plate 1.3 and far beyond the outside of the cylinder base 1, forming a towering tower.

[0026] The caisson structure of the present application is a combination of prefabrication and cast-in-situ. The cylinder base 1 and the inner cylinder 2.1 are prefabricated onshore, ensuring the quality and accuracy of the key components. After the caisson is towed to the site, the outer cylinder 2.2 is poured in sections on top of the inner cylinder 2.1, gradually and controllably increasing the total weight of the structure. This gradually increasing weight acts as a sinking force, slowly and smoothly sinking the cylinder base 1 until the bottom plate 1.1 is seated at the design elevation. This design avoids the huge difficulties and risks of towing and lifting the traditional monolithic caisson in ultra-deep water.

[0027] The cylinder base 1 of the present application provides a stable base, and the cylinder body 2 is prefabricated with the inner cylinder 2.1 and cast-in-situ with the outer cylinder 2.2, balancing quality and flexibility. This structure is particularly suitable for ultra-deep water environments, and the height of the outer cylinder 2.2 can be flexibly adjusted according to the actual water depth, solving the problem of height limitation of single component; greatly reducing the scale and risk of offshore lifting operations, reducing the use of large special ships, and effectively controlling the engineering cost.

[0028] In other embodiments of the present application, the cylinder base 1 structure described above is optimized, specifically, as shown in Figure 1 and 2 The inner wall 1.4 and the plurality of caisson inner ribs 1.5 are further arranged in the cavity of the cylinder base 1. Manholes are opened on the caisson inner ribs 1.5 to facilitate the passage of construction personnel.

[0029] The inner wall 1.4 is a cylindrical reinforced concrete wall coaxially arranged with the cylinder base 1. The caisson inner rib 1.5 is a vertical support rib plate, the upper and lower ends of which are fixedly connected with the top plate 1.3 and the bottom plate 1.1 respectively. One side of the caisson inner rib 1.5 is connected with the inner side of the annular side plate 1.2, and the other side extends radially inward until it is connected with the outer side of the inner wall 1.4 (part of the side wall of the caisson inner rib 1.5 is connected with the side wall of the inner cylinder 2.1).

[0030] The inner wall 1.4 and the caisson inner rib 1.5 together divide the large cavity inside the cylinder base 1 into multiple small compartments, and the manholes on the caisson inner rib 1.5 facilitate the passage of construction personnel. This grid-like support system greatly enhances the overall stiffness and strength of the cylinder base 1. When the cylinder base 1 bears the huge load transmitted by the upper tower and the external water pressure and wave force, these inner walls 1.4 and inner ribs can effectively disperse and transmit the load to the bottom plate 1.1 and the foundation, avoiding excessive deformation of the top plate 1.3, the bottom plate 1.1 and the side plate 1.2.

[0031] The embodiment forms a grid support in the cylinder base 1, and the internal grid support system converts the cylinder base 1 from a cavity structure to a honeycomb structure, and the bending, shearing and torsional resistance is significantly improved. The inner wall 1.4 and the inner rib 1.5 of the caisson ensure that the load is uniformly transmitted from the cylinder 2 to the bottom plate 1.1 and the steel pipe pile 4 foundation, reducing stress concentration and improving structural durability. The multiple cabins formed in the cylinder base 1 facilitate the placement of ballast in different zones during construction, allowing for more accurate adjustment of the level during sinking.

[0032] In a further embodiment of the present application, the embodiment explicitly loads the cavity of the cylinder base 1 with ballast 1.6 during the sinking construction process of the caisson. These ballasts can serve as temporary loads at the beginning of construction and can be replaced by permanently poured concrete as permanent ballasts at the later stage of construction.

[0033] The ballast 1.6 is used to increase the structural self-weight and provide the required gravity for sinking. By adjusting the distribution and weight of the ballast 1.6 in different cabins, the draft depth and horizontal attitude of the cylinder base 1 can be accurately controlled to ensure smooth and vertical sinking.

[0034] The design of the ballast 1.6 in the cylinder base 1 can accurately control the sinking process, effectively overcome the interference of environmental factors such as water flow and waves on the attitude of the caisson, and ensure construction safety. The ballast 1.6 can be made of inexpensive materials such as sand and water, which is low in cost and easy to operate.

[0035] The present application also relates to a construction method, and the construction method of the present application is used for constructing the caisson structure described above. Specifically, the construction method of the present application comprises the following steps: S1: flattening and reinforcing the water bottom at the caisson construction site, as shown in Figure 3 ; S2: prefabricating the cylinder base 1 and the inner cylinder 2.1 of the caisson in the shore-side prefabrication plant; S3: building a trestle 3 at the caisson construction site, as shown in Figure 5 ; S4: transporting the prefabricated cylinder base 1 (including the inner cylinder 2.1) to the trestle 3 by floating, as shown in Figure 4 ; S5: accurately positioning the cylinder base 1; S6: adjusting the draft depth and level of the cylinder base 1, and partially pouring the outer cylinder 2.2 on the top of the inner cylinder 2.1 in stages until the bottom plate 1.1 of the cylinder base 1 is completely sunk to the water bottom, as shown in Figure 6 ; S7: backfilling the water bottom around the cylinder base 1 with riprap to form a protection.

[0036] The construction method of the present application is land prefabrication, water assembly and staged loading sinking. Through a series of orderly steps, the complex offshore cast-in-situ operation is converted into a controllable, prefabricated-based assembly and incremental operation.

[0037] The construction method of the present application divides the entire construction process into clear, standardizable operation steps, improving management efficiency and construction quality; the construction method of the present application prefabricates the key structure on the shore, only performs pouring and assembly on site, and is less affected by bad sea conditions. Each step is linked, ensuring seamless connection from foundation treatment to structure installation to protection.

[0038] In some embodiments of the present application, the step S1 described above is optimized, and specifically, as shown in Figure 3 The water bottom leveling and reinforcing method of the present embodiment includes the following steps: S11: A large grab ship is used to excavate the water bottom at the caisson construction position to form a foundation trench at the design elevation; The excavation is divided into two stages, rough excavation and fine excavation, the purpose of which is to remove the surface layer of the water bottom at the caisson construction position; S12: In the foundation trench, a plurality of steel pipe piles 4 are inserted and driven according to the design position as the foundation support of the caisson bottom plate 1.1; The steel pipe piles 4 inserted and driven in the foundation trench serve the purpose of reinforcement and support, and the steel pipe piles 4 are completely inserted and driven into the water bottom soil layer without direct fixed connection with the bottom plate 1.1 of the cylinder seat 1; The insertion and driving of the steel pipe piles 4 are based on the operation of a pile driving ship, which is anchored by a mooring line to a concrete cat; S13: Throw and fill well-graded gravel into the foundation trench to form a gravel layer 7; S14: Compact the gravel layer 7 to improve its density and bearing capacity; Through precise positioning of the barge side vibration hammer trolley, the vibration rammer is lowered to the top of the gravel and compacted to the design elevation; The gravel vibration and ramming equipment used in the present embodiment includes a barge, a support frame is installed on the barge, a horizontal track is provided on the support frame, a movable trolley is provided on the track and can move along the track, the movable trolley is driven by a motor on the barge; a lifting tool is connected to the lower end of the movable trolley, and a vibration rammer is installed on the lifting tool; a lifting auxiliary equipment is also installed on the support frame; when in use, the up and down movement of the vibration rammer is controlled by driving the movable trolley; S15: Finally, use the underwater leveling robot scraper to scrape the surface of the compacted gravel layer 7 to ensure that the flatness meets the requirements.

[0039] In this process, as Figure 3As shown, a circle of bubble emitting devices 8 is arranged around the construction area, the bubble emitting devices 8 include gas pipes 9 through which gas is supplied to the bubble emitting devices 8, the bubble emitting devices 8 generate fine bubbles in the water, forming a circle of barriers to prevent the pollution generated by the construction from spreading around.

[0040] The purpose of the embodiment is to create a foundation with high strength and high flatness. The steel pipe pile 4 provides deep bearing capacity, the gravel layer 7 serves as a leveling layer and a stress dispersion layer, and ramming and screeding ensure that the caisson bottom plate 1.1 can bear force uniformly.

[0041] The foundation treatment method of the embodiment combines the advantages of pile foundation and composite foundation, providing extremely stable support for the giant caisson. Fine flatness control avoids uneven stress on the bottom plate 1.1, preventing structural tilting or cracking.

[0042] In other embodiments of the application, the embodiment optimizes the above step S3, specifically, a semicircular construction trestle 3 is erected at the caisson construction site. The center of the trestle 3 coincides with the design center of the caisson (and the axis of the cylinder base 1), and is arranged around the outside of the caisson. The trestle 3 itself is fixed in the construction water area by steel piles, that is, a plurality of steel piles are first inserted around the design position of the construction area, and the construction of the concrete panels of the trestle 3 is based on the steel piles. The concrete panels are composed of a plurality of unit panels spliced together, the two sides of the unit panels are provided with joint welding steel plates, adjacent unit panels are connected to each other through the joint welding steel plates, the unit panels are provided with lifting eye holes for convenient lifting and installation; in addition, the unit panels are also provided with welding plates, which are structures for welding connection with cross beams, facilitating the connection of adjacent unit panels in the transverse direction.

[0043] The semicircular ring-shaped trestle 3 provides a stable annular working platform for the positioning, leveling, concrete pouring, material transportation and personnel operation of the caisson. Its coaxial arrangement ensures the accessibility and convenience of operating the caisson from all directions.

[0044] During construction, workers and equipment can approach the caisson from any radial position, with high construction efficiency. The trestle 3, as a temporary structure, has strong stability and can provide reliable protection for long-term construction.

[0045] In further embodiments of the application, the embodiment optimizes the above step S6, specifically, by placing or removing temporary loads (such as standard weight sandbags or counterweights) in different compartments of the cylinder base 1, the overall weight and center of gravity of the cylinder base 1 are changed, thereby achieving accurate adjustment of the draft and levelness.

[0046] Through calculation and experiment, the embodiment can control the floating state of the structure by increasing or decreasing the weight in a specific compartment, so that the structure reaches the expected sinking depth and remains level.

[0047] The adjustment method of the embodiment has high control precision and can realize dynamic fine adjustment, and the precision is much better than that of simply relying on concrete pouring. The adjustment method is simple to operate and low in cost: no complex equipment is needed, and general materials can be used to realize the method.

[0048] In the preferred embodiment of the present application, the method of the step S6 of pouring the outer cylinder 2.2 in stages is optimized, and specifically, the process is divided into three stages. S61: After the initial positioning and leveling are completed, a formwork is erected on the top of the inner cylinder 2.1, and the first part (the first part accounts for 40% of the entire outer cylinder 2.2, and in actual construction, the value is not limited to this value, and can be set according to actual conditions) of the outer cylinder 2.2 is poured; S62: After the first part of concrete reaches the predetermined strength, a formwork is erected on the top of the first part, and the second part (the second part accounts for 36% of the entire outer cylinder 2.2, and in actual construction, the value is not limited to this value, and can be set according to actual conditions) of the outer cylinder 2.2 is poured; S63: After the bottom plate 1.1 of the cylinder base 1 is completely sunk to the bottom of the water, a formwork is erected on the top of the second part, and the third part (the third part accounts for 24% of the entire outer cylinder 2.2, and in actual construction, the value is not limited to this value, and can be set according to actual conditions) of the outer cylinder 2.2 is poured until the design elevation.

[0049] The step of pouring the outer cylinder 2.2 in stages in the embodiment is equivalent to increasing the load in stages. The weight increased in each stage is controllable, so that the structure and the hydrological foundation have a gradual adaptation process, and sudden sinking or structural damage caused by instantaneous loading is avoided.

[0050] The pouring method is load-controllable, ensures that the sinking process is stable and uniform, and avoids “sudden sinking” accidents. The pouring method ensures the quality of concrete, and the layered pouring is beneficial to the dissipation of concrete hydration heat, reduces temperature cracks, and ensures the final molding quality.

[0051] In another embodiment of the present application, the step S6 is further optimized, and specifically, after the pouring construction of the second part of the outer cylinder 2.2 is completed (after S62 and before S63), concrete is poured into the cabin of the cylinder base 1 to form a permanent ballast.

[0052] In the key stage of structure sinking, the high-density concrete replaces the temporary ballast to provide a final and irreversible sinking force, and serves as a permanent counterweight of the structure to ensure the anti-floating stability of the structure during use.

[0053] This embodiment of the permanent ballast construction method provides a one-time solution, integrating the permanent ballast with the structure and offering permanent anti-buoyancy safety. By organically combining the ballast process with the main structure pouring process, the overall construction period is optimized.

[0054] In a preferred embodiment of this application, step S7 described above has been optimized, specifically including the following steps: S71: Divide the underwater design filling area around cylinder seat 1 into multiple virtual squares of equal area; S72: The trebuchet throws stones into each square in a zigzag pattern, first forming a graded filter layer 6 on the gravel layer 7. S73: On top of the filter layer 6, larger-diameter stones are thrown to form the anti-erosion riprap layer 5.

[0055] The grid combined with the "Z"-shaped dumping method ensures the uniformity of the filling and prevents the formation of voids or accumulations. The filter layer 6 formed by the "fine to coarse" dumping sequence can prevent fine soil particles from being sucked out by the water flow, while the surface erosion protection layer can directly resist the scouring effect of the water flow.

[0056] This embodiment of the riprap backfilling method produces high-quality backfill, with a uniform and dense backfill that effectively transmits lateral earth pressure, enhancing the overall stability of the caisson. It also boasts excellent erosion resistance, and the double-layer protection system provides long-term protection for the caisson foundation, extending the structural lifespan.

[0057] During actual construction, follow these steps: 1. Foundation treatment: At the designed location, a foundation trench is formed by excavating the underwater area; Multiple steel pipe piles 4 were driven into the foundation trench according to the design, such as Figure 3 As shown; The crushed stone is dumped, compacted, and leveled to form a flat, high-bearing-capacity crushed stone foundation. 2. Prefabrication and Transportation: At the onshore prefabrication plant, the caisson's base 1 (including bottom plate 1.1, annular side plate 1.2, and top plate 1.3) and inner cylinder 2.1 are precast, and the inner wall 1.4 and caisson inner rib 1.5 are cast inside the base 1 to form an overall structure with grid compartments. The prefabricated caisson structure was floated to the construction site, such as Figure 4 As shown; 3. Construct a construction platform: A semi-circular trestle bridge 3 will be built around the caisson as a construction platform, such as... Figure 5 As shown; 4. Positioning and Initial Adjustment: The caisson was towed to the center of the area encircled by the trestle bridge 3 for precise positioning; The draft and level of the caisson are precisely adjusted by placing temporary loads as ballast in different compartments; 5. Pouring in stages: First stage pouring: Formwork is built on the top of the inner cylinder 2.1, and the first part of the outer cylinder 2.2 is poured, and the increased weight makes the caisson slowly sink; Second stage pouring: After the first part of the concrete is stable, the second part of the outer cylinder 2.2 is poured, and the caisson continues to sink; Pouring permanent ballast: After the second stage of pouring is completed, permanent ballast (concrete) is poured into the compartments of the cylinder base 1, providing greater sinking force; Final sinking: Continue to load until the bottom plate 1.1 of the cylinder base 1 is completely and stably seated on the prepared water bottom foundation; Third stage pouring: The third part of the outer cylinder 2.2 is poured on the top of the second part until the design height, completing the construction of the entire tower cylinder structure, as shown in Figure 6 ; 6. Foundation protection: After the caisson is in place, a rock-throwing ship is used to divide the area around the cylinder base 1 into a grid, and the rock is thrown in a "Z" shaped route; First, graded gravel is thrown to form a filter layer 6, and then large stones are thrown to form a scour protection layer 5, completing the permanent protection of the entire structure foundation, as shown in Figure 1 .

[0058] Through the above complete process, the technical difficulties faced in the construction of high-rise tower cylinder structures in ultra-deep water environments are successfully solved, and a safe, economical, reliable and efficient integrated solution is provided.

[0059] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection claimed by the present application is defined by the appended claims and their equivalents.

Claims

1. A tower barrel type caisson structure for ultra deep water, characterized by, The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof.

2. A tower barrel caisson structure for ultra deep water as claimed in claim 1, wherein, The application relates to a tower cylinder type caisson structure and a construction method thereof.

3. A tower barrel caisson structure for ultra deep water as claimed in claim 1, wherein, The application relates to a tower cylinder type caisson structure and a construction method thereof.

4. A construction method, characterized by, The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof.

5. A method of construction as claimed in claim 4 wherein, The application relates to a tower cylinder type caisson structure and a construction method thereof.

6. A method of construction as claimed in claim 4 wherein, The application relates to a tower cylinder type caisson structure and a construction method thereof.

7. A method according to claim 4, wherein, The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof. The application relates to a tower cylinder type caisson structure and a construction method thereof. 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A method of construction as claimed in claim 4 wherein, The method for pouring the outer cylinder (2.2) on the top of the inner cylinder (2.1) comprises the following steps: after the water depth and levelness of the cylinder base (1) are adjusted, a template is built on the top of the inner cylinder (2.1) to pour the first part of the outer cylinder (2.2); after the first part is completely stabilized, a template is built on the top of the first part to pour the second part of the outer cylinder (2.2); after the bottom plate (1.1) of the cylinder base (1) is completely sunk to the bottom of the water, a template is built on the top of the second part to pour the third part of the outer cylinder (2.2), and the pouring construction of the outer cylinder (2.2) is completed.

9. A method of construction as claimed in claim 8 wherein, After the pouring construction of the second part of the outer cylinder (2.2) is completed, permanent ballast (1.6) is poured into the cylinder base (1) until the bottom plate (1.1) of the cylinder base (1) is completely sunk to the bottom of the water.

10. A method of construction as claimed in claim 5 wherein, The method for backfilling the bottom of the water around the cylinder base (1) with riprapping comprises the following steps: the designed riprapping area of the bottom of the water around the cylinder base (1) is divided into multiple squares, each square is thrown according to a Z-shaped route, and a filter layer (6) is formed on the gravel layer (7); the anti-scouring riprapping (5) is thrown on the filter layer (6).

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