A new type of HDPE gravity net cage system and its construction method

Abstract

The application discloses a novel HDPE gravity type net cage system and a construction method thereof. The net cage system comprises a net cage frame, a flexible netting system and a mooring system. The net cage frame is connected with the seabed through the mooring system. The flexible netting system is installed in the net cage frame. The net cage frame comprises a lifting rope, an upper floating pipe structure and a lower floating pipe structure. The upper floating pipe structure is connected with the top of the lower floating pipe structure through the multiple lifting ropes. The inner sides of the upper floating pipe structure and the lower floating pipe structure are provided with frame-tying ropes which are connected with the flexible netting system. The bottom of the lower floating pipe structure is connected with the mooring system. The floating pipe component is preferably a standard component. The structure is simple and can be conveniently assembled. The load transmission path of the net cage is optimized, the load and the local load component of the net cage are reduced, the integrated design purpose is achieved, the sea space can be saved to the maximum extent compared with the traditional net cage anchor arrangement form, the utilization rate of the breeding sea area can be greatly improved, and the overall economic benefit is improved.

Description

Technical Field

[0001] This invention relates to the technical field of gravity gabion systems, and in particular to a novel HDPE gravity gabion system and its construction method. Background Technology

[0002] With limited nearshore aquaculture space, deep-sea aquaculture relies heavily on marine aquaculture cages, especially wave-resistant gravity cages. Benefiting from the high strength and price advantage of HDPE materials, most offshore cages currently utilize HDPE main frame structures, resulting in various types, including floating HDPE circular cages, floating HDPE square cages, lifting HDPE circular cages, metal frame cages, and floating rope cages. Traditional gravity cages maintain water volume by adding weights to the bottom to stretch the netting. The netting is often made of flexible material, which presents challenges. Firstly, in environments with high current speeds exceeding 1 m / s, the netting deforms significantly, leading to excessive loss of aquaculture volume. Secondly, strong winds and waves cause the main frame structure to be insufficiently strong, resulting in severe buckling and deformation. The anchoring system also requires reinforcement, often resulting in a large mooring radius and high anchoring costs, ultimately leading to poor overall aquaculture economics.

[0003] Therefore, in order to cope with strong typhoons and severe sea conditions, ensure the aquaculture volume and strength of net cages, and reduce the sea area used by a single net cage in order to improve the efficiency of large-scale net cage aquaculture, it is urgent to design a new type of gravity net cage system. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and propose a novel HDPE gravity gabion system and its construction method. By optimizing the load transfer path of the main frame, the mesh system, and the anchoring system of the gabion, the load on the gabion and the local load components are reduced, achieving the goal of integrated design, ultimately reducing the cost of the gabion and improving the overall economic benefits.

[0005] The objective of this invention is achieved through the following technical solution: a novel HDPE gravity-fed gabion system, comprising a gabion frame, a flexible netting system, and a mooring system. The gabion frame is connected to the seabed via the mooring system. The flexible netting system is installed within the gabion frame. The gabion frame includes slings, an upper floating tube structure, and a lower floating tube structure. The upper floating tube structure includes multiple annular floating tubes and brackets, with the annular floating tubes connected side-by-side via brackets. The lower floating tube structure includes multiple component-ring floating tubes and clamp connectors, with the component-ring floating tubes connected by multiple clamp connectors, resulting in a cross-sectional shape resembling a grid. The upper floating tube structure is connected to the top of the lower floating tube structure via multiple slings. Both the upper and lower floating tube structures have mooring ropes on their inner sides, which are connected to the flexible netting system. The bottom of the lower floating tube structure is connected to the mooring system, thus optimizing the load transfer path of the gabion.

[0006] Furthermore, the clamp connector includes a stop block, a left clamp component, and a right clamp component. The left clamp component and the right clamp component are spliced ​​together. Each of the left clamp component and the right clamp component has a large circular hole arranged vertically side by side for inserting the force-shaping ring float tube. Each of the left clamp component and the right clamp component also has a small circular hole. Multiple stop blocks are arranged on both sides of the clamp connector for fastening and locking the clamp connector.

[0007] Furthermore, the thickness of the clamp connector is 0.2 times the diameter of the force-shaping ring float tube.

[0008] Furthermore, the bracket has multiple circular holes for inserting annular floating tubes, and the bracket is equipped with handrails and walkway steps.

[0009] Furthermore, both the annular float and the force-sharing float are high-density polyethylene round tubes, and the interior of the force-sharing float is filled with water or sand to maintain the counterweight.

[0010] Furthermore, the flexible netting system includes a rope, a top net, side nets, and a bottom net. The rope is arranged longitudinally and laterally in the top net, side nets, and bottom net. The top net is connected to the upper floating tube structure via a tie rope. The side nets are connected to the inner sides of the upper floating tube structure and the lower floating tube structure via tie ropes, respectively. The bottom net is connected to the force-sharing floating tube located on the upper inner side of the lower floating tube structure via a tie rope.

[0011] Furthermore, a counterweight is provided at the bottom of the bottom net to maintain the shape of the net.

[0012] Furthermore, the mooring system includes multiple anchor cables and an anchor body. The multiple anchor cables are evenly arranged around the perimeter of the cage frame. One end of the anchor cable is connected to the force-sharing floating pipe at the bottom of the lower floating pipe structure, and the other end of the anchor cable is connected to the anchor body. The anchor cables and the anchor body are connected in a tensioned manner and form an angle with the sea level. The anchor points of all anchor cables are located on the same horizontal circle.

[0013] A construction method for the above-mentioned novel HDPE gravity gabion system includes the following steps:

[0014] 1) On shore, the prefabricated handrails, annular floating pipes and force ring floating pipes are assembled using round pipe sealing joints. Then, the annular floating pipes and force ring floating pipes are connected by prefabricated brackets and clamp connectors, and the handrails are installed. The clamp connectors are then locked by the stop blocks on both sides. Finally, the walkway steps are installed on the upper floating pipe structure to complete the assembly of the entire cage frame.

[0015] 2) According to the deployment requirements of the rope and flexible netting system, the netting of the top net, side net and bottom net is tied to the ropes arranged longitudinally and laterally using net lines to expand the netting and form a flexible netting skeleton. The binding and assembly of each piece of netting and rope is completed on the shore in sequence.

[0016] 3) The cage frame is towed to the designated sea area by tugboat. After the cage frame floats and stabilizes, the flexible netting system is installed by binding the frame with mooring ropes. The extended ends of the top net's ropes are connected to the mooring ropes and tied to the upper handrail. The extended ends of the side net's ropes are connected to the mooring ropes and tied to the inner floating pipes of the cage frame. The outer side of the bottom net is circumferentially connected to the mooring cable and tied to the force ring floating pipe located on the upper inner side of the lower floating pipe structure. The force ring floating pipe is pre-filled with water and sandbags are evenly suspended to achieve complete submersion. The lowering speed of the force ring floating pipe is controlled by the hoisting rope connected to the force ring floating pipe located on the upper outer side of the lower floating pipe structure, so that the force ring floating pipe is lowered to the designated water depth. At this time, the bottom of the bottom netting stretches and opens vertically under the gravity of the force ring floating pipe.

[0017] 4) After the netting is installed, the cage frame is installed in the designated sea area using the mooring system. The pre-laid anchor cables are then tied around the force ring float located on the lower outer side of the lower float structure. The remaining anchor cables are tied in sequence. The force ring float is kept in the designated position by adjusting the anchor cable pretension. Then the sandbags tied to the force ring float are removed, completing the integrated construction of the HDPE gravity cage system structure.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0019] 1. This invention provides a novel gravity-type cage system that is easy to assemble and has good resistance to current and typhoons. By optimizing the load transfer path of the cage frame, the netting system, and the anchoring system, the load on the cage and the local load components are reduced, achieving the purpose of integrated design, ultimately reducing the cost of the cage and improving the overall economic benefits.

[0020] 2. The present invention adopts a tensioned mooring system, which on the one hand achieves the function of resisting wind and current, and on the other hand can greatly save the sea area occupied by a single cage, realize the arrangement of multiple cages in a limited sea area, and improve the efficiency of intensive marine aquaculture.

[0021] 3. The cage frame components and accessories of the present invention are all standard parts, and are made of high-strength, highly malleable HDPE material, which can be mass-produced and reduce manufacturing costs;

[0022] 4. The cage frame system and netting system of the present invention are manufactured in sections and then assembled on the shore, which can save time occupied by the general assembly site. Attached Figure Description

[0023] Figure 1 This is a structural schematic diagram of a new type of HDPE gravity cage system.

[0024] Figure 2 This is a structural side view of a novel HDPE gravity cage system.

[0025] Figure 3 This is a top view of the structure of a new type of HDPE gravity cage system.

[0026] Figure 4 This is a schematic diagram of the motion state of a new type of HDPE gravity cage system under the action of strong winds and waves.

[0027] Figure 5 This is a schematic diagram of the cage frame structure.

[0028] Figure 6 This is a structural schematic diagram of the clamp connector.

[0029] Figure 7 This is a side view of the clamp connector.

[0030] Figure 8 This is a structural diagram of the bracket.

[0031] Figure 9 This is an enlarged structural diagram of a new type of HDPE gravity cage system.

[0032] Figure 10 This is one of the schematic diagrams showing the stress state of a new type of HDPE gravity cage system.

[0033] Figure 11This is the second schematic diagram of the stress state of the new HDPE gravity cage system. Detailed Implementation

[0034] The present invention will be further described below with reference to specific embodiments.

[0035] Example 1

[0036] See Figures 1 to 9 As shown, the novel wind and wave resistant HDPE gravity cage system provided in this embodiment includes a cage main frame 1, a netting system 2, and an anchoring system 3. The cage frame 1 floats on the sea surface and is connected to the seabed through the anchoring system 3. The netting system 2 is connected to the inside of the cage frame 1 through a mooring rope 26.

[0037] The cage frame 1 includes a suspension rope 25, an upper floating pipe structure composed of three annular floating pipes 11, and a lower floating pipe structure 12 composed of four force-shaping ring floating pipes at the bottom of the cage. The upper floating pipe structure is connected to a handrail 13 and a walkway tread 14. The annular floating pipes 11 and the force-shaping ring floating pipes are connected by suspension ropes 25. The three annular floating pipes 11 are connected and fixed side by side by brackets 15. The force-shaping ring floating pipes are connected and fixed by clamp connectors 16, so that the cross-sectional shape of the lower floating pipe structure forms a grid-like shape.

[0038] Both the annular float and the force-sharing float are standard hollow circular pipes. The annular float has a size of φ450sdr17, and the force-sharing float has a size of φ315sdr9. The force-sharing float is filled with water or sand to increase the counterweight at the bottom of the net and maintain the volume of the net cage.

[0039] The bracket 15 is an integrated three-channel structure made of high-density polyethylene through injection molding. It contains a channel round hole 151 and an inner small round hole 152. The inner small round hole 152 can connect to a small round tube with a diameter of φ140mm or φ63mm. Three rows of inner small round holes 152 are arranged vertically on the side for connecting the handrail 13. The handrail is made of a round tube with a diameter of φ125mm, and three tubes are arranged vertically.

[0040] The clamp connector 16 is a four-hole structure bracket. The clamp connector includes a stop block, a left clamp component, and a right clamp component. The left clamp component and the right clamp component are spliced ​​together. Each of the left clamp component and the right clamp component has a large circular hole 161 arranged vertically and horizontally, as well as multiple small circular holes 162. The large circular holes 161 are used to connect the force-sharing ring float tube, and the small circular holes 162 are used to connect small-diameter circular tubes. The thickness of the clamp connector 16 is approximately 0.2 times the diameter of the force-sharing ring float tube. It has a total of 4 stop blocks 163 on both sides, which can be used to finally lock it in place.

[0041] The location of the cable mooring point of the lower floating pipe structure conforms to the stress characteristics of the net cage. The force-sharing floating pipe 121 is connected to the sling 25, the force-sharing floating pipe 122 is connected to the bottom net reinforcing frame rope 26, and the force-sharing floating pipe 123 is connected to the anchor cable 31. With this connection method, the net cage will be subjected to an upward net torque, and the net cage will move upward. This connection arrangement can effectively resist the excessive sinking movement of the net cage.

[0042] The flexible netting system 2 includes steel ropes 24, a top net 21, a bottom net 22, and side nets 23. The netting wire diameter is 2.1mm, and the material is ultra-high molecular weight polyethylene. Multiple longitudinal and transverse steel ropes 24 with a wire diameter of 20mm are evenly distributed in the middle of each netting to form the netting skeleton. The load of each netting is transferred to the main frame 1 of the net box through the steel ropes, and then the load energy is absorbed by the anchor cable 31. The outer side of the bottom netting 22 is connected to a thicker mooring rope 26, which is used to bear and absorb the load of the bottom netting and to connect to the force-sharing floating pipe located on the upper inner side of the lower floating pipe structure.

[0043] The mooring system 3 includes anchor cables 31 and anchors 32. The mooring system is a tensioned mooring system. The mooring cables are 60mm diameter PP cables. There are 28 anchor cables, which are evenly distributed. When the cables are taut, they form an angle of 25 to 30° with the sea level. All anchor points are located on the same horizontal circle, and the mooring radius of the circle where the anchor points are located is 15.49m.

[0044] The working principle of this novel gravity-type cage system is as follows:

[0045] See Figure 10 When the cage is subjected to the combined force of wind, waves and current in the V1 direction, the upper annular floating pipe 11 of the cage frame shifts away from the initial position under the action of this force, and the lower force-sharing floating pipe 12 moves in the same direction. Furthermore, since the anchor cable 31 exerts a force on the force-sharing floating pipe 12, the anchor cable 31 is in a tensioned state. At this time, the cage frame is in an unbalanced state under the combined action of multiple forces such as wind, waves and current, and anchor cable force.

[0046] See Figure 11 After the cage is moved by wind, waves and current, the annular floating pipe 11 on the cage begins to rise and fall under the drag of the force ring floating pipe 12 via the suspension rope 25. At the same time, under the pull of the anchor cable 31, the cage will have a small swaying motion. The overall horizontal movement amplitude of the cage is smaller than that of a conventional catenary mooring cage, and the movement range is limited to a circle with a circumference of 12m. The anchor cable 31 on the wave-facing side is kept taut, while the anchor cable on the wave-repelling side is less taut.

[0047] Example 2

[0048] The construction method of the novel HDPE gravity gabion system according to Embodiment 1 provided in this embodiment includes the following steps:

[0049] 1) On shore, the prefabricated handrails, annular floating pipes and force ring floating pipes are assembled using round pipe sealing joints. Then, the annular floating pipes and force ring floating pipes are connected by prefabricated brackets and clamp connectors, and the handrails are installed. The clamp connectors are then locked by the stop blocks on both sides. Finally, the walkway steps are installed on the upper floating pipe structure to complete the assembly of the entire cage frame.

[0050] 2) According to the deployment requirements of the rope and flexible netting system, the netting of the top net, side net and bottom net is tied to the ropes arranged longitudinally and laterally using net lines to expand the netting and form a flexible netting skeleton. The binding and assembly of each piece of netting and rope is completed on the shore in sequence.

[0051] 3) The cage frame is towed to the designated sea area by tugboat. After the cage frame floats and stabilizes, the flexible netting system is installed by binding the frame with mooring ropes. The extended ends of the top net's ropes are connected to the mooring ropes and tied to the upper handrail. The extended ends of the side net's ropes are connected to the mooring ropes and tied to the inner floating pipes of the cage frame. The outer side of the bottom net is circumferentially connected to the mooring cable and tied to the force ring floating pipe located on the upper inner side of the lower floating pipe structure. The force ring floating pipe is pre-filled with water and sandbags are evenly suspended to achieve complete submersion. The lowering speed of the force ring floating pipe is controlled by the hoisting rope connected to the force ring floating pipe located on the upper outer side of the lower floating pipe structure, so that the force ring floating pipe is lowered to the designated water depth. At this time, the bottom of the bottom netting stretches and opens vertically under the gravity of the force ring floating pipe.

[0052] 4) After the netting is installed, the cage frame is installed in the designated sea area using the mooring system. The pre-laid anchor cables are then tied around the force ring float located on the lower outer side of the lower float structure. The remaining anchor cables are tied in sequence. The force ring float is kept in the designated position by adjusting the anchor cable pretension. Then the sandbags tied to the force ring float are removed, completing the integrated construction of the HDPE gravity cage system structure.

[0053] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Therefore, any changes made in accordance with the shape and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A construction method for a novel HDPE gravity gabion system, characterized in that, The novel HDPE gravity cage system includes a cage frame, a flexible netting system, and a mooring system. The cage frame is connected to the seabed via the mooring system. The flexible netting system is installed inside the cage frame. The cage frame includes slings, an upper floating tube structure, and a lower floating tube structure. The upper floating tube structure includes multiple annular floating tubes and brackets. The annular floating tubes are connected side-by-side via the brackets, which are equipped with handrails and walkways. The lower floating tube structure includes multiple component ring floating tubes and clamp connectors. The lower floating pipe structure is connected by multiple clamp connectors, forming a grid-like cross-sectional shape. The interior of the force-shaping ring floating pipe is filled with water to maintain the counterweight. The upper floating pipe structure is connected to the top of the lower floating pipe structure by multiple hoisting ropes. Both the upper and lower floating pipe structures have mooring ropes on their inner sides, which are connected to the flexible netting system. The bottom of the lower floating pipe structure is connected to the mooring system, optimizing the load transfer path of the net cage. The clamp connectors include a stop block, a left clamp component, and a right clamp component. The left and right clamp components are spliced ​​together. Each of the left and right clamp components has large, parallel circular holes for inserting the force-shaping ring float tube. Each of the left and right clamp components also has small circular holes. Multiple stop blocks are located on both sides of the clamp connector for fastening and locking the clamp connector. The flexible netting system includes ropes, a top net, side nets, and a bottom net. The ropes are arranged longitudinally and laterally in the top, side, and bottom nets. The top net is connected to the upper float tube structure via a tie rope. The side nets are connected to the inner sides of the upper and lower floating pipe structures respectively via mooring ropes. The bottom net is connected to the force-sharing floating pipe located on the upper inner side of the lower floating pipe structure via mooring ropes. The mooring system includes multiple anchor cables and an anchor body. The multiple anchor cables are evenly arranged around the perimeter of the net cage frame. One end of each anchor cable is connected to the force-sharing floating pipe at the bottom of the lower floating pipe structure, and the other end of each anchor cable is connected to the anchor body. The anchor cables and the anchor body are connected in a tensioned manner and form an angle with the sea level. The anchor points of all anchor cables are located on the same horizontal circle. The construction method includes the following steps: 1) On shore, the prefabricated handrails, annular floating pipes and force ring floating pipes are assembled using round pipe sealing joints. Then, the annular floating pipes and force ring floating pipes are connected by prefabricated brackets and clamp connectors, and the handrails are installed. The clamp connectors are then locked by the stop blocks on both sides. Finally, the walkway steps are installed on the upper floating pipe structure to complete the assembly of the entire cage frame. 2) According to the deployment requirements of the flexible netting system, the netting of the top net, side net and bottom net is tied to the longitudinal and transverse distributed ropes in sequence using net lines to expand the netting and form a flexible netting skeleton. The binding and assembly of each piece of netting and ropes is completed on the shore in sequence. 3) The cage frame is towed to the designated sea area by tugboat. After the cage frame floats and stabilizes, the flexible netting system is installed by binding the frame with mooring ropes. The extended ends of the top net ropes are connected to the mooring ropes and tied to the upper handrail. The extended ends of the side net ropes are connected to the mooring ropes and tied to the inner floating pipes of the cage frame. The outer side of the bottom net is circumferentially connected to the mooring cable and tied to the force ring floating pipe located on the upper inner side of the lower floating pipe structure. The force ring floating pipe is pre-filled with water and sandbags are evenly suspended to achieve complete submersion. The lowering speed of the force ring floating pipe is controlled by the hoisting rope connected to the force ring floating pipe located on the upper outer side of the lower floating pipe structure, so that the force ring floating pipe is lowered to the designated water depth. At this time, the bottom of the bottom netting stretches and opens vertically under the gravity of the force ring floating pipe. 4) After the netting is installed, the cage frame is installed in the designated sea area using the mooring system. The pre-laid anchor cables are then tied around the force ring float located on the lower outer side of the lower float structure. The remaining anchor cables are tied in sequence. The force ring float is kept in the designated position by adjusting the anchor cable pretension. Then the sandbags tied to the force ring float are removed, completing the integrated construction of the HDPE gravity cage system structure.

2. The construction method of a novel HDPE gravity gabion system according to claim 1, characterized in that: The thickness of the clamp connector is 0.2 times the diameter of the force-shaping ring float tube.

3. The construction method of a novel HDPE gravity gabion system according to claim 1, characterized in that: The bracket has multiple circular holes for inserting annular float tubes.

4. The construction method of a novel HDPE gravity gabion system according to claim 1, characterized in that: Both the annular float and the force-sharing float are high-density polyethylene round tubes.

5. The construction method of a novel HDPE gravity gabion system according to claim 1, characterized in that: The bottom of the bottom net is equipped with a counterweight to maintain the shape of the net.

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