A floatation assisting structure for reducing the draft of a immersed tube segment and a method for installing the same

Abstract

The application relates to a floatation assisting structure for reducing the draught of a immersed tube segment and a mounting method thereof. The floatation assisting structure for reducing the draught of the immersed tube segment comprises float boxes arranged symmetrically on two sides and connected by a bottom support. Under the action of the buoyancy of the float boxes on the two sides, the bottom support can lift the immersed tube segment upwards, so that the immersed tube segment can have a shallower draught during floatation, the immersed tube segment has a shallower draught, the excavation depth of a long-distance shallow and narrow waterway can be reduced, the engineering quantity is smaller, the construction period is shorter, and the cost is lower; the influence of the excavation of the waterway on existing buildings and structures is reduced, and the influence on the ecological environment in the waterway range is smaller. The risk of grounding during the tide passing in the window period is smaller, and in some places where the water depth meets the demand, the tide passing in the window period is not needed, so that the conditions for floatation of the immersed tube segment are easier to meet.

Description

Technical Field

[0001] This invention relates to the field of immersed tube floating technology, and in particular to a buoyancy aid structure for reducing the draft of immersed tube sections and its installation method. Background Technology

[0002] Currently, immersed tunnels are increasingly widely used in transportation projects spanning rivers, lakes, and seas. However, due to the constraints of prefabrication yard location, these yards are often far from the tunnel site, requiring temporary waterways to transport the tunnel sections to the tunnel for installation. Given current immersed tunnel specifications and floating technology, the draft of the sections often reaches approximately 10 meters. Therefore, strict control over the bottom elevation of the temporary waterway is crucial, resulting in substantial dredging and rock drilling work, long construction periods, and high costs. Furthermore, in immersed tunnel projects within urban core areas, the floating waterway often runs alongside numerous existing buildings and structures, such as subways, tunnels, utility tunnels, and bridges. The safety impact of waterway excavation on these structures cannot be ignored. This significantly constrains the overall project's cost, safety, and overall performance.

[0003] The water transport process for immersed tunnel sections is determined by a comprehensive comparison of factors such as water transport distance, channel wave and current conditions, and existing equipment. Methods such as tugboat floating transport, winch floating transport, tugboat + winch floating transport, and barge transport can be adopted.

[0004] The above-mentioned water transport technology currently used for floating and transporting immersed tunnel sections has the following problems:

[0005] 1. The existing immersed tunnel water transport method has a relatively deep overall draft, which makes the excavation of long-distance shallow and narrow channels a huge project with a long construction period and high cost.

[0006] 2. Due to the deep draft, channel excavation often involves rock drilling, which adversely affects the safety of nearby existing buildings and structures. Furthermore, existing rock drilling techniques generate significant noise, hindering civilized construction practices and nighttime work in urban core areas. Large-scale underwater excavation projects also have a substantial impact on the ecological environment of the surrounding waters, affecting fish populations and vegetation.

[0007] 3. Due to the deep draft of the immersed tunnels under current technology, they often have to pass through during the tide window, which poses a risk of running aground midway. In addition, the safety risks during the floating and transporting of the immersed tunnels are also relatively high. Summary of the Invention

[0008] The purpose of this invention is to address the problem of excessive draft of immersed tunnel sections in existing water transport processes, and to provide a buoyancy-aiding structure and its installation method for reducing the draft of immersed tunnel sections.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A buoyancy aid structure for reducing the draft of a submerged pipe section includes pontoons symmetrically arranged on both sides, the pontoons on both sides being connected by a bottom support, and a placement space between the pontoons on both sides being located above the bottom support.

[0011] The buoyancy-aiding structure for reducing the draft of the immersed tunnel section described in this scheme connects the two pontoons on both sides to form a whole through a bottom support. The space between the two pontoons, located above the bottom support, serves as the placement space for the immersed tunnel section. By placing the tunnel section above the bottom support, because the draft of the buoyancy-aiding structure is less than the draft of the tunnel section itself, the tunnel section can be supported upwards by the bottom support. Furthermore, the pontoons on both sides provide upward buoyancy to the tunnel section, allowing it to float in a shallower draft during transport. In this scheme, because the pontoons are subjected to significant pressure, their structural strength must meet the requirements of actual use, such as using steel pontoons or various alloy pontoons that meet structural strength requirements.

[0012] Furthermore, the pontoons on both sides are symmetrically arranged, which means they are symmetrical about the longitudinal central axis of the immersed tunnel section, thus ensuring the balance of both sides of the immersed tunnel section.

[0013] Furthermore, the friction between the immersed tunnel section and the bottom support ensures a relatively stable positional relationship between the immersed tunnel section and the buoyancy aid structure that reduces the draft of the immersed tunnel section, guaranteeing continuous buoyancy assistance during the floating of the tunnel section. If the positional relationship between the immersed tunnel section and the buoyancy aid structure is unstable, connecting the immersed tunnel section to the buoyancy aid structure can ensure a stable shallow draft during floating.

[0014] The buoyancy-assisted structure described in this solution, which reduces the draft of the immersed tunnel segment, allows the bottom support to lift the segment upwards under the buoyancy of the pontoons on both sides. This results in a shallower draft during the floating process, thus reducing the excavation depth of long, shallow, and narrow channels, leading to less work, shorter construction time, and lower costs. Furthermore, it reduces the impact of channel excavation on existing structures and the ecological environment within the channel area. The risk of grounding during high tide is also lower, and in areas where the water depth meets the requirements, it may not even be necessary to use high tide during the window period, making it easier to meet the conditions for floating the immersed tunnel segment.

[0015] As a preferred embodiment of the present invention, the base support includes a plurality of base support components, all of which are arranged at intervals along the longitudinal direction of the immersed tube section.

[0016] The bottom support uses support components spaced longitudinally along the immersed tube section, which facilitates connection with the buoyancy box, and each individual support component has higher structural strength. Compared to a single, integral bottom support, the longitudinally spaced support components are lighter, which helps reduce the draft of the buoyancy aid structure itself, which reduces the draft of the immersed tube section. Furthermore, it saves materials and lowers costs.

[0017] As a preferred embodiment of the present invention, the bottom support component is connected to the bottom of the pontoon at both ends, and the end of the bottom support component is aligned with or extends beyond the side of the pontoon away from the submerged tube section.

[0018] The connection length is longer, the connection effect is better, and the bottom of the pontoon can be strengthened, resulting in higher overall structural strength.

[0019] As a preferred embodiment of the present invention, the base support component includes a first component and a second component, the first component and the second component being arranged opposite each other about the longitudinal centerline of the immersed tube section, and the adjacent ends of the first component and the second component being detachably connected by a docking assembly.

[0020] The buoyancy-aiding structure for reducing the draft of the immersed tunnel section is divided into two transverse sides, facilitating its installation on both sides and the bottom of the tunnel section. The first and second components are detachably connected via a docking assembly to form a unified structure that aids buoyancy of the tunnel section. Furthermore, after use, the buoyancy-aiding structure can be easily removed from the tunnel section using the docking assembly and can be reused.

[0021] As a preferred embodiment of the present invention, the docking assembly can adjust the docking length, adapt to immersed tube sections of different widths, and more easily install the buoyancy aid structure that reduces the draft of the immersed tube section at the designated position of the immersed tube section. After installation, the immersed tube section and the buoyancy aid structure that reduces the draft of the immersed tube section are more compact as a whole, and the floating is more stable.

[0022] As a preferred embodiment of the present invention, the docking assembly includes a first docking component and a second docking component, the first docking component and the second docking component are arranged opposite to each other about the longitudinal centerline of the immersed tube section, and the connection length of the first docking component and the second docking component can be adjusted to facilitate the adjustment of the width of the base support.

[0023] As a preferred embodiment of the present invention, the bottom support includes a buffer pad layer, which is located between the two floating boxes and above the bottom support component. The buffer pad layer is in direct contact with the bottom of the immersed tunnel section. The buffer pad layer can prevent the bottom support component from directly contacting the buffer pad layer, thereby reducing the possibility of damage to the bottom surface of the immersed tunnel section due to impacts when installing the buoyancy aid structure that reduces the draft of the immersed tunnel section and when floating the immersed tunnel section.

[0024] As a preferred embodiment of the present invention, the pontoon has a connection point, which is connected to the mooring pile on the immersed tube section by a steel rope; the immersed tube section is connected to the pontoon by the steel rope, and the immersed tube section is fixed together with the buoyancy aid structure that reduces the draft of the immersed tube section, so as to ensure stable shallow draft during floating.

[0025] And / or,

[0026] The pontoon is equipped with a water inlet, which allows water to be injected or pumped into the pontoon. This is used to adjust the draft of the buoyancy aid structure that reduces the draft of the immersed tube section. It also facilitates the installation of the buoyancy aid structure that reduces the draft of the immersed tube section and can be used to adjust the lateral balance of the floating process.

[0027] As a preferred embodiment of the present invention, the bottom of the pontoon is inclined, and the bottom elevation of the side of the pontoon closer to the immersed tube section is lower than the bottom elevation of the side of the pontoon farther from the immersed tube section.

[0028] By tilting the bottom of the pontoon, the buoyancy of the water on the pontoon is tilted upwards towards one side of the immersed tunnel section. When the left and right attitudes of the immersed tunnel section are unbalanced, the buoyancy of the pontoon can correct the attitude of the immersed tunnel section. Therefore, the stability of the immersed tunnel section during floating and transportation is improved, and safety is enhanced.

[0029] A method for installing a buoyancy-aiding structure to reduce the draft of a submerged tunnel section, employing the aforementioned buoyancy-aiding structure, includes the following steps:

[0030] S1. Water is poured into the pontoons on both sides of the buoyancy aid structure that reduces the draft of the immersed tunnel section, so that the top height of the first and second components of the buoyancy aid structure that reduces the draft of the immersed tunnel section is lower than the bottom height of the immersed tunnel section.

[0031] S2. Move the buoyancy aid structure that reduces the draft of the immersed tube section to below the immersed tube section, so that the immersed tube section is located between the two pontoons and above the first and second components.

[0032] S3. Drain the water from the pontoon to make it float, so that the first and second components come into contact with the bottom of the submerged pipe section.

[0033] S4. After adjusting the distance between the two pontoons to match the width of the immersed tube section, the corresponding first and second components are connected and fixed by the first and second docking components of the bottom support.

[0034] S5. Connect and fix the mooring piles on the immersed tunnel section and the connection points on the pontoon using steel ropes;

[0035] S6. Drain the water inside the pontoon to bring the draft of the submerged pipe section to the preset value.

[0036] The installation method of the buoyancy aid structure for reducing the draft of the immersed tunnel section as described in this scheme involves increasing the draft of the buoyancy aid structure to allow it to be moved to below the immersed tunnel section. Then, by decreasing the draft of the buoyancy aid structure, the docking operation of the first and second docking components of the bottom support is facilitated. The immersed tunnel section is then fixed to the pontoon to ensure a stable overall structure. Finally, the water inside the pontoon is pumped out, allowing the buoyancy aid structure to achieve the preset draft of the immersed tunnel section. This installation method requires no manipulation of the immersed tunnel section and enables rapid, stable, and safe installation in water. The buoyancy aid structure can stably assist in the floating of the immersed tunnel section, reducing its floating draft.

[0037] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0038] 1. The buoyancy-assisted structure for reducing the draft of the immersed tunnel segment as described in this invention, under the buoyancy of the pontoons on both sides, allows the bottom support to lift the immersed tunnel segment upwards, thus enabling the segment to float in a shallower draft during transport. This shallower draft reduces the excavation depth of long, shallow, and narrow waterways, resulting in less work, shorter construction time, and lower costs. Furthermore, it reduces the impact of waterway excavation on existing structures and has a smaller impact on the ecological environment within the waterway area. The risk of grounding during high tide is also lower, and in areas where the water depth meets the requirements, it may not even be necessary to navigate during high tide, making it easier to meet the conditions for floating the immersed tunnel segment.

[0039] 2. The buoyancy-aiding structure for reducing the draft of immersed tunnel sections according to the present invention includes a bottom support comprising several bottom support components. Each bottom support component includes a first component and a second component. The adjacent ends of the first and second components are detachably connected via a docking assembly. The docking assembly is adjustable in length to accommodate immersed tunnel sections of different widths. It also facilitates the easier installation of the buoyancy-aiding structure for reducing the draft of the immersed tunnel sections at designated locations on the tunnel sections. After installation, the immersed tunnel sections and the buoyancy-aiding structure together are more compact, resulting in more stable floating. The pontoon can be used for immersed tunnel sections of different widths within a certain range, thereby enabling the reuse of immersed tunnel sections of different sizes and reducing equipment research and development and manufacturing costs. Furthermore, the water injection volume of the pontoon can be calculated based on the weight and dimensions of the immersed tunnel sections and the pontoon dimensions, according to the immersed tunnel section freeboard control standard, achieving precise adjustment.

[0040] 3. The buoyancy aid structure for reducing the draft of the immersed tunnel section described in this invention, by tilting the bottom of the pontoon, causes the buoyancy of the water on the pontoon to tilt upwards towards one side of the immersed tunnel section. When the left and right attitudes of the immersed tunnel section are unbalanced, the buoyancy of the pontoon can correct the attitude of the immersed tunnel section. Therefore, it can make the immersed tunnel section more stable during floating and transportation, and improve safety.

[0041] 4. The installation method of the buoyancy aid structure for reducing the draft of the immersed tube section described in this invention can be installed quickly, stably and safely in water without manipulating the immersed tube section. This allows the buoyancy aid structure for reducing the draft of the immersed tube section to stably assist in the floating of the immersed tube section and reduce the floating draft of the immersed tube section. Attached Figure Description

[0042] Figure 1 This is a front view of the buoyancy-aiding structure for reducing the draft of the immersed tube section as described in this invention;

[0043] Figure 2 This is a front view of the base;

[0044] Figure 3 This is a schematic diagram of the interior of the pontoon;

[0045] Figure 4 This is a front view of the buoyancy aid structure for reducing the draft of the immersed tube section during installation.

[0046] Figure 5 This is a schematic diagram of the bottom surface of the buoyancy-aiding structure for reducing the draft of the immersed tube section as described in this invention;

[0047] Figure 6 This is a schematic diagram of the bottom surface of the buoyancy aid structure for reducing the draft of the immersed tube section as described in this invention, in its installation state.

[0048] Figure 7 This is a structural diagram of the docking components.

[0049] Icons: 1-Immersed pipe section; 11-Anti-anchoring layer; 12-Precast concrete edge protection block; 13-Mooring pile; 2-Floating box; 21-Connection point; 22-Water injection port; 23-Longitudinal stiffening rib; 24-Vertical stiffening rib; 3-Steel rope; 4-Bottom support; 41-First component; 42-Second component; 43-Docking assembly; 431-First docking component; 432-Second docking component; 433-Bolt hole; 434-Bolt; 44-Buffer pad layer; 5-Placement space. Detailed Implementation

[0050] The present invention will now be described in detail with reference to the accompanying drawings.

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0052] Example 1

[0053] This embodiment provides a buoyancy aid structure to reduce the draft of the submerged pipe section. See [link to relevant documentation]. Figures 1-6 It includes pontoons 2 located on both sides and symmetrically arranged. The pontoons 2 on both sides are connected by a base 4. There is a placement space 5 between the pontoons 2 on both sides, and the placement space 5 is located above the base 4.

[0054] In this scheme, the bottom support 4 should have a certain rigidity, be able to stably support the immersed tube section 1 upwards, and ensure that the distance between the two pontoons 2 remains unchanged after the two sides are connected.

[0055] The buoyancy-aiding structure for reducing the draft of the immersed tunnel section described in this scheme connects the two pontoon boxes 2 on both sides to form a whole through the bottom support 4, such as... Figure 1 As shown, the space between the two pontoons 2 and above the bottom support 4 is the placement space 5 for the immersed tunnel section 1. The immersed tunnel section 1 is placed above the bottom support 4, as shown... Figure 4 As shown, because the buoyancy-aiding structure that reduces the draft of the immersed tunnel section is less than the draft of tunnel section 1, tunnel section 1 can be supported upwards by the bottom support 4, and the two side pontoons 2 can provide upward buoyancy to both sides of tunnel section 1, thus allowing tunnel section 1 to float in a shallower water during transport. In this scheme, because the pontoons 2 are subjected to greater pressure, the structural strength of the pontoons 2 needs to meet the actual usage requirements, such as using steel pontoons or various alloy pontoons that meet structural strength requirements. Alloy pontoons can be made of materials such as aluminum alloy. Generally, using steel pontoons is the best option.

[0056] like Figure 1 and Figure 4 As shown, the pontoons 2 on both sides are symmetrically arranged, meaning they are symmetrical about the longitudinal central axis of the immersed tunnel section 1, ensuring the balance of both sides of the immersed tunnel section 1. Furthermore, under normal circumstances, because the draft of the buoyancy-aiding structure that reduces the draft of the immersed tunnel section is less than the draft of the immersed tunnel section 1, the immersed tunnel section 1 exerts a downward squeezing force on the bottom support 4, creating friction. This friction between the immersed tunnel section 1 and the bottom support 4 ensures a relatively stable positional relationship between the immersed tunnel section 1 and the buoyancy-aiding structure that reduces the draft of the immersed tunnel section, guaranteeing that the buoyancy-aiding structure can continuously assist in buoyancy during the floating of the immersed tunnel section 1.

[0057] If the positional relationship between the immersed tunnel section 1 and the buoyancy aid structure that reduces the draft of the immersed tunnel section is unstable—that is, if the friction between the immersed tunnel section 1 and the bottom support 4 alone cannot guarantee a relatively stable positional relationship—then a stable shallow draft can be ensured during floating by connecting the immersed tunnel section 1 to the buoyancy aid structure that reduces the draft of the immersed tunnel section. In this embodiment, "shallow draft" is a relative term, meaning that the draft can be reduced compared to the actual draft of the immersed tunnel section 1. The extent to which the draft can be reduced depends on the specific dimensions and weight of the immersed tunnel, as well as the dimensions, weight, and water volume of the buoy 2.

[0058] As a preferred implementation method, such as Figure 4 As shown, the pontoon 2 has a connection point 21, which is connected to the mooring bollard 13 on the immersed tunnel section 1 via a steel rope 3. The steel rope 3 can be a steel wire rope or steel strand, etc. The steel rope 3 connects the immersed tunnel section 1 to the pontoon 2, fixing the immersed tunnel section 1 to the buoyancy aid structure that reduces the draft of the immersed tunnel section, ensuring stable shallow draft during floating. The mooring bollard 13 on the immersed tunnel section 1 can also be used for towing and floating the immersed tunnel section 1. The connection point 21 on the pontoon 2 can be a welded lifting ring, etc., that is, the lifting point on the pontoon 2 is used as the connection point 21. Figure 1 As shown, the connection point 21 is located on the upper surface of the float 2, allowing the steel cable 3 to be straightened without bending, thus extending its service life. Furthermore, in this embodiment, as... Figure 4 As shown, precast concrete edge protection blocks 12 are provided on both sides of the top of the immersed tunnel section 1. The top of the immersed tunnel section 1 has an anti-anchoring layer 11. It is connected to the pontoon 2 through the mooring pile 13, which can reduce the damage to the pontoon 2. Moreover, the height of the pontoon 2 is lower than that of the precast concrete edge protection blocks 12, so that the steel rope 3 can be better stressed and avoid positional conflict with the precast concrete edge protection blocks 12.

[0059] With the buoyancy-assisted structure for reducing the draft of the immersed tunnel section as described in this embodiment, the bottom support 4 can lift the immersed tunnel section 1 upwards under the buoyancy of the pontoons 2 on both sides. This allows the immersed tunnel section 1 to float in shallower water during the floating process. A shallower draft reduces the excavation depth of long-distance, shallow, and narrow waterways, resulting in less work, shorter construction time, and lower costs. It also reduces the impact of waterway excavation on existing structures and the ecological environment within the waterway area. Furthermore, the risk of grounding during high tide is lower, and in areas where the water depth meets the requirements, it may not even be necessary to float during high tide, making it easier to meet the conditions for floating the immersed tunnel section 1. The buoyancy-assisted structure for reducing the draft of the immersed tunnel section 1 is mainly used to reduce the draft of the immersed tunnel section 1. The floating of the immersed tunnel section 1 still requires the use of other equipment, such as tugboat floating, winch floating, tugboat + winch floating, and barge transport.

[0060] In this embodiment, as Figure 5 and Figure 6 As shown, the two pontoons 2 can each be considered as a single unit. Because the pontoon 2 has a relatively long longitudinal length along the immersed tube and a relatively wide width, it needs to be reinforced. For example... Figure 3 As shown, the inner wall of the pontoon 2 has an internal support structure that strengthens the pontoon 2. Specifically, the inner wall of the pontoon 2 has longitudinal stiffening ribs 23 arranged along the longitudinal direction of the immersed tube section 1. The longitudinal stiffening ribs 23 are spaced apart to ensure the longitudinal strength of the pontoon 2; and vertical stiffening ribs 24 are provided on the inner sides of the longitudinal end faces of the pontoon 2 to strengthen the longitudinal end faces of the pontoon 2. The strength of the pontoon 2 is ensured through the above reinforcement. The longitudinal stiffening ribs 23 and the vertical stiffening ribs 24 can be made of angle steel, H-beams, or other structural steel.

[0061] In this embodiment, a buffer pad 44 can also be provided on the side of the bottom support 4 that contacts the immersed tube section 1. The buffer pad 44 is located between the two floating boxes 2 on both sides, and the buffer pad 44 is in direct contact with the bottom of the immersed tube section 1. Figure 4 As shown, the buffer pad 44 prevents the bottom support components from directly contacting the buffer pad 44, thus reducing the possibility of damage to the bottom surface of the immersed tunnel section due to impacts during the installation of the buoyancy aid structure that reduces the draft of the immersed tunnel section and during the floating and transporting of the immersed tunnel section 1. The buffer pad 44 needs to have a certain strength to provide support for the buoy box 2. For example, the buffer pad 44 can be made of high-strength rubber buffer pads or other buffer pads with a certain strength.

[0062] Except, such as Figure 1 and Figure 3 As shown, the pontoon 2 is equipped with a water inlet 22, through which water can be injected or pumped into the pontoon 2. This is used to adjust the draft of the buoyancy aid structure that reduces the draft of the immersed tunnel section, facilitating the installation of the buoyancy aid structure and adjusting the lateral balance of the floating process. In this embodiment, the water inlet 22 is located on the top surface of the pontoon 2, maximizing the utilization of the pontoon 2's internal cavity. The water inlet 22 and the connection point 21 connecting to the mooring bollard 13 on the immersed tunnel section 1 can coexist, or only one of them can exist.

[0063] In a preferred embodiment, the bottom of the pontoon 2 is inclined, and the bottom elevation of the side of the pontoon 2 closest to the immersed tube section 1 is lower than the bottom elevation of the side of the pontoon 2 furthest from the immersed tube section 1. For example... Figure 3 and Figure 4As shown, by tilting the bottom of the pontoon 2 as a self-balancing structure for the submerged tunnel section 1, the buoyancy of the water on the pontoon 2 tilts upwards towards the submerged tunnel section 1. When the submerged tunnel section 1 is unbalanced from left to right, the buoyancy of the pontoon 2 can correct the attitude of the submerged tunnel section 1, thus making the submerged tunnel section 1 more stable and improving safety during floating. When the bottom support 4 is connected to the bottom of the pontoon 2, the bottom support can also form a tilted bottom structure, causing the buoyancy of the water on the pontoon 2 to tilt upwards towards the submerged tunnel section 1.

[0064] Using the buoyancy aid structure for reducing the draft of the immersed tube section as described in this embodiment, during installation, the entire buoyancy aid structure for reducing the draft of the immersed tube section is placed in the water. Then, water is injected into the pontoon 2 to increase the draft of the buoyancy aid structure for reducing the draft of the immersed tube section, so that the immersed tube section 1 can be directly towed to the space 5 between the two pontoons 2 and above the bottom support 4, which is the placement space of the immersed tube section 1. Then, the water in the pontoon 2 is pumped out, so that the buoyancy aid structure for reducing the draft of the immersed tube section can help the immersed tube section 1 float.

[0065] Example 2

[0066] This embodiment provides a buoyancy aid structure to reduce the draft of the immersed tube section. Based on embodiment 1, the bottom support structure can be further optimized. The bottom support 4 includes several bottom support components, and all the bottom support components are arranged at intervals along the longitudinal direction of the immersed tube section 1.

[0067] In this embodiment, the bottom support 4 uses bottom support components spaced longitudinally along the immersed tube section 1, which facilitates connection with the buoy 2. Each individual bottom support component has higher structural strength, such as using H-beams or other steel structural members. Compared to a single, integral bottom support 4, the longitudinally spaced components result in a lighter structure, which helps reduce the draft of the buoyancy aid structure itself, thus reducing the draft of the immersed tube section. Furthermore, it saves materials and lowers costs. The longitudinal spacing of the bottom support components can be adjusted according to actual needs.

[0068] Besides directly connecting the bottom support component to the float 2 as a whole, the position of the bottom support component connecting to the float 2 can also be optimized, such as... Figure 4 As shown, the bottom support component is connected to the bottom of the pontoon 2 at both ends, and the ends of the bottom support component are aligned with or extend beyond the side of the pontoon 2 away from the immersed tube section 1. A longer connection length results in a better connection effect, such as by welding; and it can strengthen the bottom of the pontoon 2, leading to higher overall structural strength.

[0069] In this embodiment, if the buoyancy-aiding structure for reducing the draft of the immersed tunnel section is a single unit, then in order for the immersed tunnel section 1 to enter between the two pontoons 2, the distance between the two pontoons 2 needs to be greater than the width of the immersed tunnel section 1. This would result in a large gap between the immersed tunnel section 1 and the pontoons 2 after it enters the space, thus reducing the stability of the immersed tunnel section 1 during floating. In this embodiment, if... Figure 2 As shown, the bottom support component includes a first component 41 and a second component 42. The first component 41 and the second component 42 are arranged opposite each other about the longitudinal central axis of the immersed tube section 1. The adjacent ends of the first component 41 and the second component 42 are detachably connected by a docking assembly 43. That is, the buoyancy aid structure for reducing the draft of the immersed tube section is divided into two transverse sides, which facilitates the installation of the buoyancy aid structure for reducing the draft of the immersed tube section on both sides and the bottom of the immersed tube section 1. The detachable connection of the first component 41 and the second component 42 through the docking assembly 43 can form a whole to assist the buoyancy of the immersed tube section 1, which is convenient for installation. After installation, there can be no gap between the immersed tube section 1 and the buoy box 2, resulting in better overall stability. Moreover, after use, it can be removed through the docking assembly 43, making it easy to remove the buoyancy aid structure for reducing the draft of the immersed tube section from the immersed tube section 1 and reuse it.

[0070] In a preferred embodiment, the docking assembly 43 not only enables docking and fixing but also allows for adjustment of the docking length, accommodating immersed tube sections 1 of different widths. Furthermore, it facilitates the easier installation of the buoyancy-aiding structure that reduces the draft of the immersed tube section at the designated location on the immersed tube section 1. After installation, the immersed tube section and the buoyancy-aiding structure are more compact overall, with no gaps, resulting in more stable floating. In this embodiment, as... Figure 2 As shown, the docking assembly 43 includes a first docking component 431 and a second docking component 432. The first docking component 431 and the second docking component 432 are arranged opposite each other about the longitudinal central axis of the immersed tube section 1. The first docking component 431 and the second docking component 432 can be connected to the first component 41 and the second component 42 by welding or other fixing methods. The connection length of the first docking component 431 and the second docking component 432 is adjustable, which facilitates the adjustment of the width of the base support 4. The length can be adjusted by telescopic fixing or by different overlap lengths. In addition to adjusting the connection length, the length can also be increased.

[0071] In this embodiment, when adjusting the width of the base 4 by using different overlap lengths, such as... Figure 7As shown, the first docking component 431 has a plurality of bolt holes 433 along its length, and the second docking component 432 also has a plurality of bolt holes 433 along its length. A fixed connection can be formed by bolts 434 passing through the corresponding bolt holes 433 of the first docking component 431 and the second docking component 432. Furthermore, by changing the number of bolt connections along the length of the first docking component 431 and the second docking component 432, the overlap length can be changed, thereby changing the width of the base support 4 to accommodate immersed tube sections 1 of different widths. Figure 7 As shown, increasing the number of bolt connections along the length of the first docking component 431 and the second docking component 432 will tighten the two side buoys 2 and narrow the distance between the two side buoys 2, thus accommodating narrower immersed tunnel sections 1; decreasing the number of bolt connections along the length of the first docking component 431 and the second docking component 432 will move the two side buoys 2 further apart and increase the distance between the two side buoys 2, thus accommodating wider immersed tunnel sections 1.

[0072] In this embodiment, the buffer pad 44 is located between the two floating boxes 2 and above the bottom support component. The buffer pad 44 is in direct contact with the bottom of the immersed tube section 1 by the bottom support 4. The buffer pad 44 can prevent the bottom support component from directly contacting the buffer pad 44, thereby reducing the possibility of damage to the bottom surface of the immersed tube section due to impact when installing the buoyancy aid structure that reduces the draft of the immersed tube section and when floating the immersed tube section 1.

[0073] The buoyancy aid structure for reducing the draft of the immersed tunnel section described in this embodiment includes a base support 4 comprising several base support components, including a first component 41 and a second component 42. The adjacent ends of the first component 41 and the second component 42 are detachably connected via a docking assembly 43. The docking assembly 43 is adjustable in length to accommodate immersed tunnel sections 1 of different widths. It also facilitates the installation of the buoyancy aid structure for reducing the draft of the immersed tunnel section at designated locations on the immersed tunnel section 1. After installation, the immersed tunnel section and the buoyancy aid structure are more compact, resulting in more stable floating. The buoy box 2 can accommodate immersed tunnel sections 1 of different widths within a certain range, thus enabling the reuse of immersed tunnel sections 1 of different sizes and reducing equipment research and development and manufacturing costs. Furthermore, the water injection volume of the buoy box 2 can be calculated based on the weight and dimensions of the immersed tunnel section 1 and the dimensions of the buoy box 2, according to the freeboard control standard for the immersed tunnel section 1, achieving precise adjustment.

[0074] Example 3

[0075] This embodiment provides an installation method for a buoyancy aid structure to reduce the draft of a submerged pipe section. The method utilizes the buoyancy aid structure for reducing the draft of a submerged pipe section as described in Embodiment 2 above, and includes the following steps:

[0076] S1. Water is poured into the buoyancy aids 2 on both sides of the buoyancy aid structure that reduces the draft of the immersed tunnel section, so that the top height of the first component 41 and the second component 42 of the bottom support 4 of the buoyancy aid structure that reduces the draft of the immersed tunnel section is lower than the bottom height of the immersed tunnel section 1; In this embodiment, during the floating mooring of the immersed tunnel section 1 in the storage area, buoyancy aids 2 that reduce the draft of the immersed tunnel section need to be installed on its left and right sides. The bottom of the left buoyancy aid 2 is connected to the first component 41 of the bottom support 4, and the bottom of the right buoyancy aid 2 is connected to the second component 42 of the bottom support 4, such as Figure 4 As shown; when there is a buffer pad 44 above the first component 41 and the second component 42, the height of the buffer pad 44 is lower than that of the immersed tube section 1.

[0077] S2. The buoyancy-aiding structure for reducing the draft of the immersed tube section is moved to below the immersed tube section 1, so that the immersed tube section 1 is located between the two pontoons 2 and above the first component 41 and the second component 42; when there is a buffer pad 44 above the first component 41 and the second component 42, the immersed tube section 1 is located above the buffer pad 44; the buoyancy-aiding structure for reducing the draft of the immersed tube section can be moved using an existing moving device;

[0078] S3. Drain the water from the pontoon 2 to make it float, so that the first component 41 and the second component 42 come into contact with the bottom of the submerged pipe section 1, which will facilitate subsequent docking and installation.

[0079] S4. After adjusting the distance between the two pontoons 2 to match the width of the immersed tube section 1, the corresponding first component 41 and second component 42 are connected and fixed by the first docking component 431 and the second docking component 432 of the bottom support 4. In this embodiment, the distance between the two pontoons 2 can be adjusted by a winch device.

[0080] S5. Connect and fix the mooring pile 13 on the immersed tunnel section 1 and the connection point 21 on the pontoon 2 with steel rope 3.

[0081] S6. Drain the water inside the pontoon 2 so that the draft of the immersed tunnel section 1 reaches the preset value. That is, by simultaneously pumping water from the pontoons 2 on both the left and right sides, a shallow draft of the immersed tunnel section 1 is achieved.

[0082] The installation method of the buoyancy aid structure for reducing the draft of the immersed tunnel section described in this scheme involves increasing the draft of the buoyancy aid structure to allow it to be moved to below the immersed tunnel section 1. Then, by decreasing the draft of the buoyancy aid structure, the docking operation of the first docking component 431 and the second docking component 432 of the bottom support 4 is facilitated. The immersed tunnel section 1 is then fixed to the pontoon 2 to ensure a stable whole. Finally, the water inside the pontoon 2 is pumped out, allowing the buoyancy aid structure to achieve a preset draft for the immersed tunnel section 1. This installation method does not require manipulation of the immersed tunnel section 1 and can be installed quickly, stably, and safely in the water. The buoyancy aid structure can stably assist the floating of the immersed tunnel section 1, reducing its floating draft.

[0083] After the buoyancy aid structure for reducing the draft of the immersed tunnel section is installed, the immersed tunnel section and the buoyancy aid structure for reducing the draft of the immersed tunnel section can be transported as a whole using a water transport device.

[0084] The following effects can be achieved through the above embodiments:

[0085] First, reduce the draft of the immersed tunnel segment during the floating process, thereby effectively reducing the amount of excavation work for the floating channel, reducing costs, and shortening the construction period.

[0086] II. Self-balancing structure for immersed tunnel segment attitude: When the left and right attitudes of immersed tunnel segment 1 are unbalanced, the buoyancy of the downward chamfer of the left and right side float boxes 2 can correct the attitude of immersed tunnel segment 1, thus making the immersed tunnel segment 1 more stable and improving safety during floating.

[0087] Third, the pontoon 2 can be used for immersed tunnel sections 1 of different widths within a certain range, thereby realizing the reuse of immersed tunnel sections 1 and reducing the cost of equipment research and development and manufacturing.

[0088] Fourth, the water injection volume of pontoon 3 can be calculated based on the freeboard control standard of immersed tunnel section 1, the weight and size of immersed tunnel section 1, and the size of pontoon 2, so as to achieve precise adjustment.

[0089] Fifth, the structure of pontoon 2 is reasonably stressed, and it is convenient to connect and install with the immersed tube section 1, resulting in high work efficiency.

[0090] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A buoyancy-aiding structure for reducing the draft of a submerged pipe section, characterized in that, The system includes pontoons (2) located on both sides and symmetrically arranged. The pontoons (2) on both sides are connected by a base support (4). There is a placement space (5) between the pontoons (2) on both sides. The placement space (5) is located above the base support (4). The base support (4) includes several base support components. All the base support components are arranged at intervals along the longitudinal direction of the immersed tunnel section (1). The base support components include a first component (41) and a second component (42). The first component (41) and the second component (42) are arranged opposite each other about the longitudinal centerline of the immersed tunnel section (1). The adjacent ends of the first component (41) and the second component (42) are detachably connected by a docking assembly (43). The docking assembly (43) can adjust the docking length so that there is no gap between the immersed tunnel section (1) and the pontoons (2) after installation.

2. The buoyancy-aiding structure for reducing the draft of the submerged pipe section according to claim 1, characterized in that, The bottom support component is connected to the bottom of the pontoon (2) at both ends, and the end of the bottom support component is aligned with or extends beyond the side of the pontoon (2) away from the submerged pipe section (1).

3. The buoyancy-aiding structure for reducing the draft of the submerged pipe section according to claim 1, characterized in that, The docking assembly (43) includes a first docking component (431) and a second docking component (432). The first docking component (431) and the second docking component (432) are arranged opposite each other about the longitudinal centerline of the immersed tube section (1). The connection length of the first docking component (431) and the second docking component (432) can be adjusted.

4. The buoyancy-aiding structure for reducing the draft of the submerged pipe section according to claim 1, characterized in that, The base (4) includes a buffer pad (44) located between the two floats (2) and above the base component.

5. The buoyancy-aiding structure for reducing the draft of the submerged pipe section according to any one of claims 1-4, characterized in that, The pontoon (2) has a connection point (21), which is connected to the mooring pile (13) on the immersed tube section (1) by a steel rope (3); And / or, the float (2) is provided with a water inlet (22).

6. The buoyancy-aiding structure for reducing the draft of the submerged pipe section according to any one of claims 1-4, characterized in that, The bottom of the pontoon (2) is inclined, and the bottom elevation of the side of the pontoon (2) closer to the immersed tube section (1) is lower than the bottom elevation of the side of the pontoon (2) away from the immersed tube section (1).

7. A method for installing a buoyancy-aiding structure to reduce the draft of a submerged pipe section, characterized in that, The buoyancy-aiding structure for reducing the draft of the immersed tube section as described in any one of claims 1-6 includes the following steps: S1. Water is poured into the buoy boxes (2) on both sides of the buoyancy aid structure that reduces the draft of the immersed tube section, so that the top height of the first part (41) and the second part (42) of the bottom support (4) of the buoyancy aid structure that reduces the draft of the immersed tube section is lower than the bottom height of the immersed tube section (1). S2. The buoyancy aid structure that reduces the draft of the immersed tube section is moved to the bottom of the immersed tube section (1), so that the immersed tube section (1) is located between the two floating boxes (2) and above the first component (41) and the second component (42). S3. Drain the water from the pontoon (2) to make it float, so that the first component (41) and the second component (42) come into contact with the bottom of the submerged pipe section (1); S4. After adjusting the distance between the two pontoons (2) to match the width of the immersed tube section (1), the corresponding first part (41) and second part (42) are connected and fixed by the first docking part (431) and the second docking part (432) of the bottom support (4) so ​​that there is no gap between the immersed tube section (1) and the pontoon (2) after installation. S5. Connect and fix the mooring pile (13) on the immersed tube section (1) and the connection point (21) on the pontoon (2) with steel rope (3); S6. Drain the water inside the pontoon (2) so that the draft of the submerged pipe section (1) reaches the preset value.

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