Immersion system and immersion method for HDPE (High-Density Polyethylene) pipeline

Abstract

The invention relates to the technical field of HDPE pipeline sinking, in particular to a sinking system and method for an HDPE pipeline, and the sinking system for the HDPE pipeline comprises a plurality of air bags, hanging belts, sacrifice ropes, first lengthening hanging belts and / or second lengthening hanging belts; the air bag is connected with the hanging belt through the sacrificial rope, and the hanging belt wraps the HDPE pipeline to be immersed. The first lengthening sling and / or the second lengthening sling are / is installed between the air bag and the sling, and the first lengthening sling and / or the second lengthening sling are / is used for lengthening the distance between the air bag and the sling. According to the sinking system, the first lengthening hanging belt and / or the second lengthening hanging belt are / is arranged between the air bag and the hanging belt, first-time sinking of the pipeline is achieved after the pipeline is filled with water, one-time sinking in place is not needed, the bending stress borne by the pipeline in the initial stage of sinking is effectively reduced, and the sinking efficiency is improved. And then the distance between the air bag and the lifting belt is prolonged by selecting the first lengthening lifting belt and / or the second lengthening lifting belt according to the depth of first-time sinking, so that the pipeline is more stably and accurately sunk.

Description

Technical Field

[0001] The invention relates to the technical field of HDPE pipeline laying, and in particular to a laying system and a laying method for HDPE pipeline. Background Art

[0002] HDPE pipe (High Density Polyethylene) can be used as the seaside water intake pipe of the seawater cooling system because of its excellent properties, such as reliable connection, strong material impact resistance, outstanding crack resistance, aging resistance and corrosion resistance.

[0003] At present, the commonly used pipeline laying method is to first make the pipe section on land, seal the two ends of the pipe section with temporary sealing walls, then slide it into the water, float the pipe section in the water, and then tow it to the designed position. After positioning, load the pipe section to make it sink into the pre-dug underwater trench, and finally remove the sealing wall to connect the sections of the pipe into a whole. However, when the HDPE pipe is used as the seaside water intake pipe of the seawater cooling system, the HDPE pipe has the characteristics of large diameter (inner diameter exceeds 3m), heavy weight (pipe section length exceeds 5.5m, linear weight exceeds 0.9t / m), and long pipe section length (single section pipe length is about 100m-500m). The traditional laying method is easy to cause the HDPE pipe to be laid in place, increase unnecessary subsequent adjustment steps, and improperly increase the construction period. In addition, the driving pipeline laying method has a single laying step, and a single laying is easy to cause excessive bending and damage of the HDPE pipe, increasing the construction cost. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the existing pipeline sinking technology that is not suitable for the sinking of large-diameter, overweight and overlong HDPE pipelines, easily causes damage to the HDPE pipelines, and has low sinking accuracy, and to provide a sinking system and sinking method for HDPE pipelines.

[0005] In a first aspect, the present invention provides a sinking system for HDPE pipes, comprising a plurality of airbags, slings, a sacrificial rope, a first extension sling and / or a second extension sling; the airbag is connected to the sling via the sacrificial rope, and the sling wraps around the HDPE pipe to be sunk; the first extension sling and / or the second extension sling are installed between the airbag and the sling, and the first extension sling and / or the second extension sling are used to extend the distance between the airbag and the sling.

[0006] The traditional method of sinking the pipeline in place at one time is prone to excessive bending and damage to large-diameter, overweight, and over-length HDPE pipelines, and the sinking accuracy is low, making it difficult to resist the impact of ocean currents on the pipeline. The sinking system for HDPE pipelines provided by the present invention, by setting a first extension sling and / or a second extension sling between the airbag and the sling, realizes the first sinking of the HDPE pipeline to be sunk after the pipeline is filled with water, and does not need to be sunk in place at one time, effectively reducing the bending stress of the pipeline in the initial stage of sinking, and protecting the structural integrity of the pipeline; then, according to the depth of the first sinking, the first extension sling and / or the second extension sling are selected to extend the distance between the airbag and the sling, so that the pipeline can be sunk twice or three times in a more stable manner in subsequent operations. This step-by-step sinking method avoids the positioning deviation problem in the traditional one-time sinking, and finally completes the precise sinking of the HDPE pipeline by fine-tuning the air pressure in the airbag, greatly improving the construction accuracy. Through the precise step-by-step sinking and air pressure fine-tuning method, a large amount of subsequent adjustment work caused by inadequate sinking in the traditional method is significantly reduced. The pipeline laying is more accurate, which effectively shortens the construction period and improves the overall construction efficiency. In addition, during the multiple laying process, the pipeline can gradually adapt to the dynamic force brought by the ocean current, avoiding the risk of the pipeline being impacted or deflected by the ocean current in the one-time laying method. The step-by-step operation enhances the ability of the pipeline to resist ocean currents during the laying process and ensures the stability and safety of the laying.

[0007] Preferably, when only the first extension sling is set, the upper end of the sacrificial rope and the upper end of the first extension sling are both connected to the airbag, the lower end of the sacrificial rope and the lower end of the first extension sling are both connected to the sling, and the length of the first extension sling is ≥ the length of the sacrificial rope.

[0008] The length of the first extension sling is greater than that of the sacrificial rope, which provides a larger operating range for pipeline sinking. In the initial stage of pipeline sinking, the sacrificial rope serves to connect the airbag and the pipeline, limiting the excessive sinking of the pipeline and avoiding the bending damage of large-diameter and overweight pipelines caused by sinking too fast or too deep in one time. After the first sinking, the length of the first extension sling can be released by cutting the sacrificial rope, and the depth of the second sinking can be accurately controlled, gradually achieving accurate positioning of the pipeline and sinking it to the designed depth. The sacrificial rope and the first extension sling have clear division of labor and mutual cooperation in the entire sinking process, which can significantly reduce the number and complexity of adjustments in the sinking operation, thereby improving construction efficiency and shortening the construction period.

[0009] Preferably, when both the first extension sling and the second extension sling are provided, the upper end of the sacrificial rope and the upper end of the first extension sling are both connected to the airbag, the lower end of the sacrificial rope is connected to the sling, the lower end of the first extension sling is connected between the two ends of the sacrificial rope, the upper end of the second extension sling is connected to the lower end of the first extension sling, the lower end of the second extension sling is connected to the sling, and the length of the first extension sling and the length of the second extension sling are both ≥ the length of the sacrificial rope.

[0010] Through the step-by-step setting of the sacrificial rope, the first extension sling, and the second extension sling, multi-stage sinking operations can be achieved, which improves the adaptability and flexibility of the sinking system and adapts to the needs of different water depths, ocean current strengths, and pipeline lengths. The sinking depth of each stage can be controlled by sacrificial ropes and extension slings of different lengths, avoiding excessive bending moment loads on the pipeline during the sinking stage, and the protective effect is particularly significant for large-diameter, overweight, and over-length HDPE pipelines.

[0011] In a second aspect, the present invention provides a method for laying a HDPE pipe, using the above-mentioned laying system for a HDPE pipe, comprising the following steps:

[0012] S1: Inflate the airbags reserved for the installed HDPE pipes, and control the degree of inflation so that the butt end of the installed HDPE pipes floats to 0.8m-1.2m from the bottom of the base trench; select the length L1 of the first extension sling and / or the length L2 of the second extension sling, connect several airbags to the slings through sacrificial ropes, and wrap the HDPE pipes to be sunk with the slings. According to the number of times the sacrificial ropes are cut N, the first extension sling and / or the second extension sling are arranged between the airbags and the slings; the HDPE pipes to be sunk are moored and positioned on the water surface;

[0013] S2: Release the airbag fixing rope of the HDPE pipe to be sunk, first open the water valve at the non-butt end of the HDPE pipe to be sunk to fill it with water, then open the air valve at the butt end of the HDPE pipe to be sunk to exhaust the air and allow the HDPE pipe to sink, thus completing the first sinking of the HDPE pipe to be sunk;

[0014] S3: After the HDPE pipe to be laid is laid for the first time and stably suspended, measure the axis deviation of the HDPE pipe to be laid. If the axis deviation of the HDPE pipe to be laid exceeds 1m, make a secondary adjustment to the horizontal position and elevation of the HDPE pipe to be laid until the axis deviation of the HDPE pipe to be laid is ≤1m;

[0015] S4: Cut the sacrificial rope between the two ends of the first extension sling, release the first extension sling, and complete the secondary sinking of the HDPE pipe to be sunk. If the height of the HDPE pipe to be sunk from the bottom of the base trench after the secondary sinking is H2≤L2+1, continue to deflate the airbag to adjust the height of the HDPE pipe to be sunk, so that the butt end of the HDPE pipe to be sunk is aligned with the butt end of the installed HDPE pipe, and the sinking of the HDPE pipe to be sunk is completed;

[0016] If the height H2 of the HDPE pipe to be sunk from the bottom of the base trench after the second sinking is greater than L2+1, cut the sacrificial rope between the two ends of the second extension sling, release the second extension sling, and complete the third sinking of the HDPE pipe to be sunk. Then continue to deflate the airbag to adjust the height of the HDPE pipe to be sunk, so that the butt end of the HDPE pipe to be sunk is aligned with the butt end of the installed HDPE pipe, and complete the sinking of the HDPE pipe to be sunk.

[0017] The HDPE pipeline sinking method provided by the present invention adopts the method of air bag buoyancy assistance and gradual release of the growth sling, avoiding the operation of sinking the pipeline into place at one time. Through staged sinking (first, second (even third), final air bag deflation to fine-tune the sinking depth), the bending stress of the pipeline during the sinking process is significantly reduced, thereby protecting the structural integrity of the HDPE pipeline; the sinking depth and suspension state of the pipeline are controlled by cutting the sacrificial rope and adjusting the air bag deflation amount, so that the sinking of each stage can reach the precise position required by the design, and the measurement and adjustment of the pipeline axis deviation are carried out after the first sinking to ensure that the deviation is ≤1m, which greatly reduces the subsequent position adjustment work caused by the inadequate sinking in the traditional method; through the reasonable arrangement of the first growth sling and the second growth sling and the flexible length selection, the sinking steps and depth can be adjusted according to the specific construction environment (such as different water depths and foundation trench conditions), which has strong adaptability.

[0018] The multi-stage HDPE pipeline sinking method provided by the present invention significantly improves the protection, accuracy and efficiency of pipeline sinking by combining airbag-assisted buoyancy, multiple releases of growth slings and gradual and precise adjustment, and overcomes the defects of the traditional one-time sinking method. The method has obvious advantages in protecting the HDPE pipeline structure, reducing construction risks, improving engineering quality and economic benefits, and provides an innovative solution for the marine sinking of large-diameter, overweight and over-length HDPE pipelines.

[0019] Preferably, the number of times N of cutting the sacrificial rope is determined in S1, if the height H1 of the HDPE pipe to be laid from the bottom of the base trench after the first laying is ≤ L1 + L2 + 1, then N = 1, and if the sacrificial rope is only cut once, the second extension sling is not used;

[0020] If the height of the HDPE pipe to be laid from the bottom of the foundation trench after the first laying is H1>L1+L2+1, then N=2. If the sacrificial rope is only cut twice, both the first extension sling and the second extension sling are used.

[0021] When N=1, the second extension sling is not used, and the construction workers only need to cut the sacrificial rope once to complete the operation, simplifying the sinking process; when N=2, two extension slings are arranged in advance and used reasonably, without the need to repeatedly adjust the sling settings, which significantly improves the efficiency of the sinking operation. The number of times the sacrificial rope is cut and the use of the sling is accurately controlled through the logical judgment of the cleaning, reducing tentative operations and ensuring rapid completion of the sinking.

[0022] Preferably, the airbag reserved for the installed HDPE pipe in S1 is located within the range of 0-40m of the butt end of the installed HDPE pipe.

[0023] The reserved airbag is located within the range of 0-40m of the butt end. Local buoyancy is achieved by inflation, so that the butt end of the installed HDPE pipe is slightly floated, which provides sufficient support and ensures the stability of the butt end.

[0024] Preferably, in S2, starting from the butt-jointed end of the HDPE pipe to be laid, the fixing ropes of the airbags connected to the HDPE pipe to be laid are sequentially released toward the non-butt-jointed end of the HDPE pipe to be laid.

[0025] By adopting this method of releasing the fixing rope, starting from the butt end of the HDPE pipe to be sunk, the fixing ropes of the airbags are released in sequence towards the non-butt end, with the airbag at the butt end being released first to facilitate the subsequent water filling operation of the HDPE pipe to be sunk.

[0026] Preferably, the length L1 of the first extension sling is 4 m, and the length L2 of the second extension sling is 1 m.

[0027] The first extension sling = 4m and the second extension sling = 1m provide the system with flexible sinking adjustment space. By selecting the appropriate sling combination and the number of times the sacrificial rope is cut, the sinking depth of the HDPE pipe to be sunk can be accurately controlled to ensure that the pipeline position meets the predetermined requirements. When the initial sinking depth of the pipeline meets the conditions, the first extension sling with a longer length is used, allowing the system to gradually place the pipeline and make fine adjustments. If a greater depth adjustment is required, the second extension sling can be continued to make fine adjustments.

[0028] Preferably, the HDPE pipe to be sunk in S2 is sunk 4.5 m for the first time, and the single sinking depth of the HDPE pipe to be sunk is not more than 5 m.

[0029] Limiting the maximum depth of each sinking to 5m can effectively prevent uneven force or damage to the pipeline due to sinking too deep. Control the depth of each sinking to avoid sudden excessive load during the sinking process due to excessive sinking, and reduce the impact on the pipeline. The initial sinking depth of 4.5m is relatively moderate, ensuring that the pipeline descends steadily and maintains a certain buoyancy, preventing it from contacting the bottom of the foundation trench too early and affecting subsequent sinking operations.

[0030] Preferably, when the HDPE pipe to be sunk is filled with water in S2, a crane ship is used to lift the butt end of the HDPE pipe to be sunk so that the air valve is located above the water; when the HDPE pipe to be sunk sinks to 9-10 pipe sections, the lifting point of the crane ship is released.

[0031] Lifting the air valve to the water surface helps to discharge the gas smoothly and avoid gas pressure or blockage. By controlling the timely discharge of gas during the sinking process of the pipeline, the buoyancy caused by gas accumulation in the pipeline can be avoided, which will lead to instability in the sinking process or floating of the pipeline, affecting the efficiency of the entire sinking operation; when the pipeline to be sunk sinks to 9-10 sections, the lifting point is released, which means that the pipeline has basically completed the initial sinking, and can be further fine-tuned according to the sinking status of the pipeline. This method of gradually loosening the lifting point allows each stage of the pipeline sinking to be precisely controlled, avoiding sudden accelerated sinking of the pipeline or uneven settlement.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The sinking system for HDPE pipes provided by the present invention can realize the first sinking of the HDPE pipe to be sunk after the pipe is filled with water by setting the first extension sling and / or the second extension sling between the airbag and the sling. It is not necessary to sink the pipe in place at one time, which effectively reduces the bending stress of the pipe in the initial stage of sinking and protects the structural integrity of the pipe. Then, according to the depth of the first sinking, the first extension sling and / or the second extension sling are selected to extend the distance between the airbag and the sling, so that the pipe can be sunk twice or three times in a more stable manner in subsequent operations. This step-by-step sinking method avoids the positioning deviation problem in the traditional one-time sinking, and finally completes the precise sinking of the HDPE pipe by fine-tuning the air pressure in the airbag, greatly improving the construction accuracy. Through the precise step-by-step sinking and air pressure fine-tuning method, a large amount of subsequent adjustment work caused by inadequate sinking in the traditional method is significantly reduced. The pipeline is sunk more accurately, which effectively shortens the construction period and improves the overall construction efficiency. In addition, during the multiple laying process, the pipeline can gradually adapt to the dynamic force brought by the ocean current, avoiding the risk of the pipeline being impacted or deflected by the ocean current in the one-time laying method. The step-by-step operation enhances the pipeline's ability to resist ocean currents during the laying process and ensures the stability and safety of the laying process.

[0034] 2. The HDPE pipeline sinking method provided by the present invention adopts the method of air bag buoyancy assistance and gradual release of the growth sling, avoiding the operation of sinking the pipeline into place at one time. Through staged sinking (first, second (even third), and final air bag deflation to fine-tune the sinking depth), the bending stress on the pipeline during the sinking process is significantly reduced, thereby protecting the structural integrity of the HDPE pipeline; the sinking depth and suspension state of the pipeline are controlled by cutting the sacrificial rope and adjusting the air bag deflation volume, so that the sinking in each stage can reach the precise position required by the design, and the deviation of the pipeline axis is measured and adjusted after the first sinking to ensure that the deviation is ≤1m, which greatly reduces the subsequent position adjustment work caused by inadequate sinking in traditional methods; through the reasonable arrangement of the first growth sling and the second growth sling and the flexible length selection, the sinking steps and depth can be adjusted according to the specific construction environment (such as different water depths and foundation trench conditions), and it has strong adaptability;

[0035] 3. The HDPE pipeline sinking method provided by the present invention significantly improves the protection, accuracy and efficiency of pipeline sinking by combining airbag-assisted buoyancy, multiple releases of the growth sling and gradual and precise adjustment, and overcomes the defects of the traditional one-time sinking method. This method has obvious advantages in protecting the HDPE pipeline structure, reducing construction risks, improving engineering quality and economic benefits, and provides an innovative solution for the ocean sinking of large-diameter, overweight and over-length HDPE pipelines. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic diagram of a sinking system for HDPE pipes in Example 2;

[0037] Figure 2 This is a schematic diagram of a sinking system for HDPE pipes in Example 3;

[0038] Figure 3 This is a schematic diagram of three sinkings;

[0039] Figure 4 This is a schematic diagram of four sinkings;

[0040] Figure 5 This is a schematic diagram of the installed HDPE pipe floating;

[0041] Figure 6 This is a schematic diagram of the water filling process of the HDPE pipe to be sunk;

[0042] Figure 7 This is a schematic diagram of the HDPE pipe to be sunk after being filled with water;

[0043] Figure 8 Schematic diagram of the HDPE pipe to be sunk by cutting the rope in one go.

[0044] Markings in the figure:

[0045] 1-airbag, 21-first extension sling, 22-second extension sling, 23-sling, 24-sacrificial rope, 3-crane vessel, 100-HDPE pipe to be sunk, 200-installed HDPE pipe. DETAILED DESCRIPTION

[0046] The present invention is further described in detail below in conjunction with specific embodiments. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0047] Unless otherwise specified, in the description of the specific embodiments of the present invention, the terms indicating the orientation or position relationship such as "up", "down", "left", "right", "center", "inside", "outside", etc. are all based on the expression of the orientation or position relationship shown in the drawings, or are the orientation or position relationship when the invented product / equipment / device is usually used. These terms of orientation or position relationship are only for the convenience of describing the scheme of the present invention or simplifying the description in the specific embodiments, so as to facilitate the technicians to quickly understand the scheme, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the present invention.

[0048] In addition, if the terms "horizontal", "vertical", "overhanging", "parallel" and the like appear, it does not mean that the corresponding devices / components / elements are required to be absolutely horizontal or vertical or overhanging or parallel, but may be slightly tilted or have deviations. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but may be slightly tilted. Alternatively, it can be simplified to mean that the corresponding devices / components / elements are set in directions such as "horizontal", "vertical", "overhanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its role in the scheme of the present invention.

[0049] In addition, the expressions “first”, “second”, “third”, etc., which appear in the terms, are merely used to distinguish the description of the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0050] In addition, in the description of the embodiments of the present invention, "several", "plurality" and "a number" represent at least 2. It can be any number such as 2, 3, 4, 5, 6, 7, 8, 9, and even more than 9.

[0051] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threading, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0052] Example 1

[0053] The traditional method of sinking the pipeline in place at one time is prone to excessive bending and damage to large-diameter, overweight, and overlong HDPE pipelines, and the sinking accuracy is low, making it difficult to resist the impact of ocean currents on the pipeline. Therefore, this embodiment provides a sinking system for HDPE pipelines, including a plurality of airbags 1, slings 23, sacrificial ropes 24, a first extension sling 21, and / or a second extension sling 22; the airbag 1 is connected to the sling 23 through the sacrificial rope 24, and the sling 23 wraps around the HDPE pipeline 100 to be sunk; the first extension sling 21 and / or the second extension sling 22 are installed between the airbag 1 and the sling 23, and the first extension sling 21 and / or the second extension sling 22 are used to extend the distance between the airbag 1 and the sling 23.

[0054] The sinking system for HDPE pipes provided in this embodiment is provided with a first extension sling 21 and / or a second extension sling 22 between the airbag 1 and the sling 23. When the pipe is filled with water, the first sinking of the HDPE pipe 100 to be sunk is realized, and it is not necessary to sink it in place at one time, which effectively reduces the bending stress of the pipe in the initial sinking stage and protects the structural integrity of the pipe; then, according to the depth of the first sinking, the first extension sling 21 and / or the second extension sling 22 are selected to extend the distance between the airbag 1 and the sling 23, so that the pipe can be sunk twice or three times in a more stable manner in subsequent operations. This step-by-step sinking method avoids the positioning deviation problem in the traditional one-time sinking, and finally completes the precise sinking of the HDPE pipe by fine-tuning the air pressure in the airbag 1, greatly improving the construction accuracy. Through the precise step-by-step sinking and air pressure fine-tuning method, a large amount of subsequent adjustment work caused by inadequate sinking in the traditional method is significantly reduced. The pipeline is sunk more accurately, thereby effectively shortening the construction period and improving the overall construction efficiency. In addition, during the multiple laying process, the pipeline can gradually adapt to the dynamic force brought by the ocean current, avoiding the risk of the pipeline being impacted or deflected by the ocean current in the one-time laying method. The step-by-step operation enhances the pipeline's ability to resist ocean currents during the laying process and ensures the stability and safety of the laying process.

[0055] Example 2

[0056] On the basis of Example 1, Figure 1 As shown, in this embodiment, only the first extension sling 21 is provided, the upper end of the sacrificial rope 24 and the upper end of the first extension sling 21 are both connected to the airbag 1, the lower end of the sacrificial rope 24 and the lower end of the first extension sling 21 are both connected to the sling 23, and the length of the first extension sling 21 is ≥ the length of the sacrificial rope 24.

[0057] The length of the first extension sling 21 is greater than the length of the sacrificial rope 24. This setting provides a larger operating range for pipeline sinking. In the initial stage of pipeline sinking, the sacrificial rope 24 serves to connect the airbag 1 and the HDPE pipe 100 to be sunk, limiting the excessively deep sinking of the pipeline and avoiding the bending damage of large-diameter and overweight pipelines caused by sinking too fast or too deep in one time. After the first sinking is in place, the length of the first extension sling 21 can be released by cutting the sacrificial rope 24, and the depth of the secondary sinking can be accurately controlled, so as to gradually achieve accurate positioning of the pipeline and sink it to the designed depth. The sacrificial rope 24 and the first extension sling 21 have clear division of labor and cooperate with each other in the entire sinking process, which can significantly reduce the number and complexity of adjustments in the sinking operation, thereby improving construction efficiency and shortening construction period.

[0058] Example 2

[0059] Different from Example 2, Figure 2 As shown, in this embodiment, when both the first extension sling 21 and the second extension sling 22 are provided, the upper end of the sacrificial rope 24 and the upper end of the first extension sling 21 are connected to the airbag 1, the lower end of the sacrificial rope 24 is connected to the sling 23, and the lower end of the first extension sling 21 is connected between the two ends of the sacrificial rope 24, preferably connected to one-half of the sacrificial rope 24; the upper end of the second extension sling 22 is connected to the lower end of the first extension sling 21, and the lower end of the second extension sling 22 is connected to the sling 23, and the length of the first extension sling 21 and the length of the second extension sling 22 are both ≥ the length of the sacrificial rope 24.

[0060] This embodiment can realize multi-stage sinking operation by setting up the sacrificial rope 24, the first extension sling 21, and the second extension sling 22 step by step, thereby improving the adaptability and flexibility of the sinking system and meeting the requirements of different water depths, ocean current strengths, and pipeline lengths. The sinking depth of each stage can be controlled by sacrificial ropes 24 and extension slings 23 of different lengths, thereby avoiding the pipeline from bearing excessive bending moment loads during the sinking stage, and the protective effect on large-diameter, overweight, and overlong HDPE pipelines is particularly significant.

[0061] Example 3

[0062] like Figure 3-Figure 8As shown, this embodiment provides a method for laying a HDPE pipe, using the laying system for a HDPE pipe provided in Example 1, comprising the following steps:

[0063] S1: Figure 5 As shown, the diver inflates the airbag 1 reserved for the installed HDPE pipe 200. In this embodiment, the airbag 1 reserved for the installed HDPE pipe 200 is arranged within a range of 0-40m from the butt end of the installed HDPE pipe 200 to the non-butt end. The diver controls the inflation degree of the airbag 1 reserved for the installed HDPE pipe 200 so that the butt end of the installed HDPE pipe 200 floats to 0.8m-1.2m from the bottom of the base trench. The local buoyancy of the installed HDPE pipe 200 is achieved by inflation, so that the butt end of the installed HDPE pipe 200 floats slightly, ensuring the stability of the butt end.

[0064] Select the length L1 of the first extension sling 21 and / or the length L2 of the second extension sling 22. Specifically, the length L1 of the first extension sling 21 can be 4m-5m, preferably L1=4m; specifically, the length L2 of the second extension sling 22 can be 1m-2m, preferably L2=1m. Connect several airbags 1 to the sling 23 through the sacrificial rope 24. The sling 23 wraps the HDPE pipe 100 to be laid. According to the number of times N of cutting the sacrificial rope 24, choose to arrange the first extension sling 21 and / or the second extension sling 22 between the airbag 1 and the sling 23;

[0065] If the height H1 of the HDPE pipe 100 to be laid from the bottom of the foundation trench after the first laying is ≤ L1 + L2 + 1, then N = 1, and if the sacrificial rope 24 is cut only once, the second extension sling 22 is not used;

[0066] If the height H1 of the HDPE pipe 100 to be laid from the bottom of the foundation trench after the first laying is greater than L1+L2+1, then N=2, and if the sacrificial rope 24 is cut only twice, both the first extension sling 21 and the second extension sling 22 are used;

[0067] The HDPE pipe 100 to be sunk is moored and positioned on the water surface;

[0068] S2: After the mooring positioning measurement and verification of both ends of the HDPE pipe 100 to be sunk are correct, starting from the butt end of the HDPE pipe 100 to be sunk, the fixing ropes of the airbag 1 of the HDPE pipe 100 to be sunk are released one by one towards the non-butt end of the HDPE pipe 100 to be sunk, so as to facilitate the subsequent water filling operation of the HDPE pipe 100 to be sunk. Once all the fixing ropes of the airbag of the HDPE pipe 100 to be sunk are untied, the conditions for water release are met.

[0069] After the diver goes into the water to check that there is no abnormality in the fastening of the positioning anchor and the airbag lashing sling 23 of the HDPE pipe 100 to be sunk, the water valve of the non-butt end of the HDPE pipe 100 to be sunk is opened first to fill water, and then the air valve of the butt end of the HDPE pipe 100 to be sunk is opened to exhaust the air and sink the HDPE pipe 100 to be sunk, and the preset airbag 1 performs the floating operation in turn, such as Figure 6 As shown, the first laying of the HDPE pipe 100 to be laid is completed.

[0070] In this embodiment, the HDPE pipe 100 to be sunk is sunk for the first time to a depth of 4.5 m, and the single sinking depth of the HDPE pipe 100 to be sunk is not greater than 5 m.

[0071] In this embodiment, when the HDPE pipe 100 to be sunk is filled with water, Figure 7 As shown, the butt end of the HDPE pipe 100 to be sunk can be lifted by the crane ship 3 so that the air valve is above the water to prevent the air valve from entering the water in advance; when the HDPE pipe 100 to be sunk is sunk to about 9-10 pipe sections remaining, the lifting point of the crane ship 3 is released. During the water filling process of the HDPE pipe 100 to be sunk, the positioning anchor of the HDPE pipe 100 to be sunk is not released, and the axis and mileage position of the HDPE pipe 100 to be sunk are monitored to ensure that the HDPE pipe 100 to be sunk is at a safe distance of more than 5m from the installed HDPE pipe 200.

[0072] S3: After the HDPE pipe 100 to be sunk is sunk for the first time and stably suspended, the axis deviation of the HDPE pipe 100 to be sunk is measured. If the axis deviation of the HDPE pipe 100 to be sunk exceeds 1m, the horizontal position and elevation of the HDPE pipe 100 to be sunk are adjusted for the second time by the winches on the crane ship and barge at both ends of the HDPE pipe 100 to be sunk, until the axis deviation of the HDPE pipe 100 to be sunk is ≤1m;

[0073] S4: Figure 3 , Figure 8 As shown, the sacrificial rope 24 between the two ends of the first extension sling 21 is cut, the first extension sling 21 is released, and the secondary laying of the HDPE pipe 100 to be laid is completed.

[0074] If the height H2 of the HDPE pipe 100 to be laid from the bottom of the trench after the second laying is less than or equal to L2+1, the airbag 1 is further deflated to adjust the height of the HDPE pipe 100 to be laid (for example, Figure 3 The butt end of the HDPE pipe 100 to be laid is aligned with the butt end of the installed HDPE pipe 200, and the laying of the HDPE pipe 100 to be laid is completed;

[0075] like Figure 4As shown, if the height H2 of the HDPE pipe 100 to be laid from the bottom of the base trench after the second laying is greater than L2+1, the sacrificial rope 24 between the two ends of the second extension sling 22 is cut, the second extension sling 22 is released, and the third laying of the HDPE pipe 100 to be laid is completed. Then, the airbag 1 is continuously deflated to adjust the height of the HDPE pipe 100 to be laid (for example, Figure 4 The butt end of the HDPE pipe 100 to be laid is aligned with the butt end of the installed HDPE pipe 200, and the laying of the HDPE pipe 100 to be laid is completed.

[0076] The HDPE pipeline sinking method provided in this embodiment adopts the method of buoyancy assistance of the airbag 1 and gradual release of the growth sling, avoiding the operation of sinking the pipeline into place at one time. By sinking in stages (first, second (even third), and final deflation of the airbag 1 to fine-tune the sinking depth), the bending stress on the pipeline during the sinking process is significantly reduced, thereby protecting the structural integrity of the HDPE pipeline. The sinking depth and suspension state of the pipeline are controlled by cutting the sacrificial rope 24 and adjusting the deflation amount of the airbag 1, so that the sinking in each stage can reach the precise position required by the design. After the first sinking, the deviation of the pipeline axis is measured and adjusted to ensure that the deviation is ≤1m, which greatly reduces the subsequent position adjustment work caused by inadequate sinking in the traditional method; through the reasonable arrangement of the first growth sling 21 and the second growth sling 22 and the flexible length selection, the sinking steps and depth can be adjusted according to the specific construction environment (such as different water depths and foundation trench conditions), which has strong adaptability.

[0077] The multi-stage HDPE pipeline sinking method provided in this embodiment significantly improves the protection, accuracy and efficiency of pipeline sinking by combining the airbag 1 auxiliary buoyancy, multiple releases of the growth sling and gradual and precise adjustment, and overcomes the defects of the traditional one-time sinking method. This method has obvious advantages in protecting the HDPE pipeline structure, reducing construction risks, improving engineering quality and economic benefits, and provides an innovative solution for the marine sinking of large-diameter, overweight and over-length HDPE pipelines.

[0078] 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 in the protection scope of the present invention.

Claims

1. A sinking system for HDPE pipes, characterized in that: It comprises a plurality of air bags (1), a sling (23), a sacrificial rope (24), a first extension sling (21) and / or a second extension sling (22); The airbag (1) is connected to the sling (23) via the sacrificial rope (24), and the sling (23) wraps around the HDPE pipe (100) to be sunk; the first extension sling (21) and / or the second extension sling (22) are installed between the airbag (1) and the sling (23), and the first extension sling (21) and / or the second extension sling (22) are used to extend the distance between the airbag (1) and the sling (23).

2. A sinking system for HDPE pipes according to claim 1, characterized in that: When only the first extension sling (21) is provided, the upper end of the sacrificial rope (24) and the upper end of the first extension sling (21) are both connected to the airbag (1), the lower end of the sacrificial rope (24) and the lower end of the first extension sling (21) are both connected to the sling (23), and the length of the first extension sling (21) is ≥ the length of the sacrificial rope (24).

3. A sinking system for HDPE pipes according to claim 1, characterized in that: When both the first extension sling (21) and the second extension sling (22) are provided, the upper end of the sacrificial rope (24) and the upper end of the first extension sling (21) are both connected to the airbag (1), the lower end of the sacrificial rope (24) is connected to the sling (23), the lower end of the first extension sling (21) is connected between the two ends of the sacrificial rope (24), the upper end of the second extension sling (22) is connected to the lower end of the first extension sling (21), the lower end of the second extension sling (22) is connected to the sling (23), and the length of the first extension sling (21) and the length of the second extension sling (22) are both ≥ the length of the sacrificial rope (24).

4. A method for laying a HDPE pipe, characterized in that: The use of the HDPE pipe sinking system according to any one of claims 1 to 3 comprises the following steps: S1: Inflate the air bag (1) reserved for the installed HDPE pipe (200), and control the degree of inflation so that the butt end of the installed HDPE pipe (200) floats to a distance of 0.8m to 1.2m from the bottom of the base trench; The length L1 of the first extension sling (21) and / or the length L2 of the second extension sling (22) are selected, a plurality of airbags (1) are connected to the sling (23) via a sacrificial rope (24), the sling (23) wraps around the HDPE pipe (100) to be laid, and the first extension sling (21) and / or the second extension sling (22) are arranged between the airbag (1) and the sling (23) according to the number of times N of cutting the sacrificial rope (24); The HDPE pipe (100) to be sunk is moored and positioned on the water surface; S2: releasing the fixing rope of the air bag (1) of the HDPE pipe (100) to be sunk, first opening the water valve of the non-butt end of the HDPE pipe (100) to be sunk to fill it with water, and then opening the air valve of the butt end of the HDPE pipe (100) to be sunk to exhaust air and allow the HDPE pipe (100) to be sunk, thus completing the first sinking of the HDPE pipe (100) to be sunk; S3: After the HDPE pipe (100) to be sunk is sunk for the first time and stably suspended, the axis deviation of the HDPE pipe (100) to be sunk is measured. If the axis deviation of the HDPE pipe (100) to be sunk exceeds 1 m, the horizontal position and elevation of the HDPE pipe (100) to be sunk are adjusted for a second time until the axis deviation of the HDPE pipe (100) to be sunk is ≤ 1 m. S4: cutting the sacrificial rope (24) between the two ends of the first extension sling (21), releasing the first extension sling (21), and completing the secondary sinking of the HDPE pipe (100) to be sunk. If the height H2≤L2+1 of the HDPE pipe (100) to be sunk from the bottom of the base trench after the secondary sinking, continue to deflate the airbag (1) to adjust the height of the HDPE pipe (100) to be sunk, so that the butt end of the HDPE pipe (100) to be sunk is aligned with the butt end of the installed HDPE pipe (200), and the sinking of the HDPE pipe (100) to be sunk is completed. If the height H2 of the HDPE pipe (100) to be laid from the bottom of the base trench after the second laying is greater than L2+1, the sacrificial rope (24) between the two ends of the second extension sling (22) is cut, and the second extension sling (22) is released to complete the third laying of the HDPE pipe (100) to be laid, and then the airbag (1) is continuously deflated to adjust the height of the HDPE pipe (100) to be laid, so that the butt end of the HDPE pipe (100) to be laid is aligned with the butt end of the installed HDPE pipe (200), and the laying of the HDPE pipe (100) to be laid is completed.

5. A method for laying a HDPE pipe according to claim 4, characterized in that: In S1, the number of times N to cut the sacrificial rope (24) is determined. If the height H1 of the HDPE pipe (100) to be laid from the bottom of the base trench after the first laying is ≤ L1+L2+1, then N=1. If the sacrificial rope (24) is only cut once, the second extension sling (22) is not used. If the height of the HDPE pipe (100) to be laid from the bottom of the base trench after the first laying is H1>L1+L2+1, then N=2, and if the sacrificial rope (24) is only cut twice, both the first extension sling (21) and the second extension sling (22) are used.

6. A method for laying a HDPE pipe according to claim 4, characterized in that: The air bag (1) reserved for the installed HDPE pipe (200) in S1 is located within a range of 0-40m from the butt end of the installed HDPE pipe (200).

7. A method for laying a HDPE pipe according to claim 4, characterized in that: In S2, starting from the butt end of the HDPE pipe (100) to be sunk, the fixing ropes of the airbag (1) connected to the HDPE pipe (100) to be sunk are sequentially released toward the non-butt end of the HDPE pipe (100) to be sunk.

8. A method for laying a HDPE pipe according to claim 4, characterized in that: The length L1 of the first extension sling (21) is 4 m, and the length L2 of the second extension sling (22) is 1 m.

9. A method for laying a HDPE pipe according to claim 4, characterized in that: The HDPE pipe (100) to be sunk in S2 is sunk 4.5 m for the first time, and the single sunk depth of the HDPE pipe (100) to be sunk is not greater than 5 m.

10. A method for laying a HDPE pipe according to claim 4, characterized in that: When the HDPE pipe (100) to be sunk is filled with water in S2, the butt end of the HDPE pipe (100) to be sunk is lifted by a crane ship (3) so that the air valve is located above the water; when the HDPE pipe (100) to be sunk is sunk to 9-10 pipe sections, the lifting point of the crane ship (3) is released.

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