Long-distance transportation method for immersed tubes of semi-submersible barge

Abstract

The invention provides a long-distance transportation method for a semi-submersible barge immersed tube, and is suitable for the field of semi-submersible barge transportation. The long-distance transportation method for the semi-submersible barge immersed tube comprises the steps of finite element analysis, mooring arrangement, transportation route planning, supporting facility configuration, transportation safety comprehensive monitoring and emergency plan establishment, and the optimal mooring point position is compared and selected through finite element analysis software. Then, static equilibrium analysis and dynamic effect analysis are carried out to determine fatigue damage and required design bearing capacity of the mooring cables, influences of catenaries are considered, the mooring forces required when the mooring cables of different materials and specifications reach the same design bearing capacity are compared, the mooring cable with the minimum mooring force is selected as the optimal mooring cable, and the optimal mooring cable with the minimum mooring force is selected as the optimal mooring cable. Cracks caused by overlarge local mooring force in the transportation process of the immersed tube are avoided; and through the improved JPS algorithm, the route path is updated in real time in the sailing process, a dangerous area is avoided, and the safety of the transportation process is ensured.

Description

Technical Field

[0001] The invention relates to the field of semi-submersible barge transportation, and in particular to a long-distance transportation method for a semi-submersible barge submerged pipe. Background Art

[0002] At present, the construction of undersea tunnels has changed from prefabricating immersed tubes at traditional construction sites to making immersed tubes in prefabricated factories, which are then transported to the construction site by semi-submersible barges. This method not only avoids the excavation restrictions on the construction site, but also significantly reduces the construction time and improves the overall efficiency and economy of the project.

[0003] However, due to the many uncertainties in maritime transportation, there are still many challenges in the process of long-distance transportation of immersed tubes by semi-submersible barges. For example, different mooring arrangements will produce significantly different tensions at the mooring points of the immersed tubes and semi-submersible barges. It is necessary to choose a reasonable mooring arrangement as much as possible to ensure the minimum tension at the mooring point of the immersed tube, and avoid excessive tension at the mooring point, which will cause local cracking of the immersed tube and affect its service life. In addition, there are many uncertainties that affect the safety of immersed tube transportation during maritime navigation, and it is necessary to continuously optimize the route during navigation to ensure transportation safety as much as possible. Summary of the invention

[0004] The purpose of the present invention is to optimize the solution to the problems of mooring arrangement and transportation safety when semi-submersible barges transport immersed tubes over long distances. A long-distance transportation method for semi-submersible barge immersed tubes is proposed, which avoids cracks in the immersed tubes due to excessive local mooring force during transportation, and also ensures the transportation safety of the semi-submersible barge during navigation. The method can be widely used in the field of semi-submersible barge transportation.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for long-distance transportation of a semi-submersible barge immersed tube, including finite element analysis of immersed tube transportation process, mooring arrangement, transportation route planning, supporting facilities configuration, comprehensive transportation safety monitoring and emergency plan establishment, characterized by:

[0007] The mooring arrangement includes the design of mooring points, the selection of mooring lines, the determination of mooring line weights and the design of connection devices;

[0008] The mooring point design adopts multi-point mooring to improve stability, and uses finite element analysis software to simulate the stress conditions of the submerged pipe under different mooring point layout schemes to select the optimal scheme;

[0009] The mooring cable selection firstly performs a static balance analysis to calculate the tension of each mooring cable in the static water state, and considers the constant environmental load to calculate the tension of the mooring cable. The time-varying characteristics of the mooring cable tension are calculated by using time domain and frequency domain methods and considering the dynamic effects of waves and wind. Based on the dynamic analysis results, the fatigue damage of the mooring cable during long-term use is evaluated, the fatigue life of the mooring cable is calculated, and the required immersed tube tension of the mooring cable under the maximum design wind speed and the maximum design water flow velocity is calculated. The sum of the required immersed tube tension and the pre-tension required for the stability of the immersed tube is used as the design bearing capacity of the mooring cable. Considering the strength, elastic modulus, corrosion resistance and fatigue life of the material, the available mooring cable materials and specifications are determined;

[0010] The weight of the mooring cable is determined by taking into account the influence of the catenary under the gravity of the mooring cable and the water resistance, and comparing the mooring forces of the mooring cables when the mooring cables of different weights are available to achieve the same design bearing capacity, and using the mooring cable corresponding to the minimum mooring force;

[0011] The connection device design includes designing reliable connection devices between the mooring cable and the immersed tube and semi-submersible barge, and performing fatigue analysis and ultimate strength verification;

[0012] The transportation route planning specifically includes the following steps:

[0013] S101. Collect data;

[0014] The data collection includes collecting the throughput capacity of all ports between the starting point and the end point, the water depth of the ports, the berthing fees and other additional charges of the ports, so as to determine whether the ports can provide the necessary services;

[0015] S102, preliminary selection of routes;

[0016] The preliminary route selection includes using the latest nautical chart data to identify feasible waterways, selecting ports that can be berthed according to the throughput capacity of the ports, the water depth of the ports and whether the ports can provide necessary services, obtaining weather forecasts along the way, including wind speed and wave height, obtaining ship traffic along the way, and avoiding bad weather and congested feasible waterways; obtaining navigation warning area warnings, International Convention for the Prevention of Pollution from Ships areas, port data and maritime safety information, excluding the above-mentioned areas from the feasible waterways, and obtaining the preliminary route;

[0017] S103, cost-benefit analysis;

[0018] The cost-benefit analysis includes calculating the sailing time of each route according to the preliminary route, estimating the fuel consumption according to the sailing speed and distance, evaluating the berthing and other costs of each port of the preliminary route, obtaining the total cost of each route, and selecting the scheduled route with the best cost;

[0019] S104, Risk assessment;

[0020] The risk assessment includes the formulation of emergency plans to deal with possible mechanical failures, damage to immersed tubes, severe weather, shoals and reefs, ship collisions, pirate activities and entry into special areas during the shipping process, and continuous monitoring of weather changes on the scheduled route and monitoring of the safety of the waterway;

[0021] S105, real-time path optimization;

[0022] The real-time optimization of the path includes dividing the global map based on the Web Mercator projection into grids, with the ratio of the grid length to the actual distance being R, and obtaining important information within a range of L nautical miles around the semi-submersible barge in real time, wherein the important information includes meteorological data, the latest navigation warning area information, ecological protection area information along the way, high-risk water area information, legally restricted area information, and shoal, reef, and seabed obstacle information; marking the grids corresponding to the areas involved in the important information in the global map as dangerous; and when the grids with the dangerous marking appear within the range, using the improved JPS algorithm to update the local path to avoid the dangerous area;

[0023] S106, Record and Feedback;

[0024] After each flight segment is completed, the important information collected in real time is recorded and saved, the actual navigation route is compared with the planned route, the deviation position is found, and a review is performed to form a case database.

[0025] Furthermore, the mooring point arrangement scheme must satisfy the requirement of symmetrical arrangement in both the horizontal and vertical directions of the immersed tube.

[0026] Furthermore, the constant environmental load includes the wind pressure load acting on the immersed tube.

[0027] P w =0.613C h C s v 2 (1)

[0028] Where P w - Wind pressure load of immersed tube, Pa, C h - Wind pressure height variation coefficient, C s - Wind load shape coefficient, v - wind speed at 10m above sea level, m / s; also includes the water flow resistance pressure acting on the immersed tube

[0029]

[0030] Where P wt - Water flow resistance pressure, Pa, ρ w- Water density, kg / m 3 , C w - water flow resistance coefficient, V-water flow velocity, m / s; the water flow velocity takes into account the towing speed of the semi-submersible barge and the natural sea current speed,

[0031] V=V s +V c +V t (3)

[0032] Where V s -Semi-submersible barge towing speed, m / s, V c -Natural current speed, m / s, V t - Flow velocity of water under the influence of tides in nearshore areas, m / s.

[0033] Furthermore, during the analysis of the dynamic effects of waves and wind, the JONSWAP wave spectrum was used to simulate the movement of the immersed tube under the action of wave loads.

[0034]

[0035] In the formula, α is a dimensionless constant; x is the length of the wind zone, m; U is the wind speed, m / s; γ is the peak-raising factor; ω is p - spectral peak frequency, Hz; σ-peak shape parameter.

[0036] Furthermore, the catenary effect includes calculating the water resistance of mooring cables of different materials.

[0037]

[0038] In the formula, F D - Mooring line water resistance, N, C D -Drag coefficient, depends on the shape of the mooring line, surface roughness and the Reynolds number of the water flow, A-projected surface area of ​​the mooring line facing the water, m 2 ; Calculate the resultant force of the mooring line water resistance and the mooring line gravity,

[0039]

[0040] In the formula, F G - the resultant force of the water resistance and gravity of the mooring cable, N, G - the gravity of the mooring cable, N; when the mooring cable with the smallest resultant force reaches the same design bearing capacity, the required mooring force is the smallest.

[0041] Furthermore, in step S105, the information of the shoal and reef seabed obstacles is acquired using a multi-beam bathymetric system and a side-scan sonar, and a high-precision seabed topographic map is drawn.

[0042] Furthermore, in step S105, the improved JPS algorithm includes defining a starting point and a target point, setting an initial value of the time dimension, adding known dynamic obstacle trajectory information to the search space, using Manhattan distance as a heuristic function, and using the canonical order of VHW to generate a path; starting from the starting point, expanding nodes in VHW order, for each possible movement, checking whether there is a time obstacle, if so, recording it and waiting at an appropriate time, if there is no obstacle, continuing to expand until the target point is found or all possible paths are explored, and outputting the optimal path finally found.

[0043] Furthermore, in step S105, the meteorological data includes air pressure, wind speed, wind direction, visibility, precipitation, wave current, sea fog and ice condition reports, wherein grids corresponding to waters with wind speed greater than the maximum design wind speed, waters with visibility less than 1 nautical mile, waters with wave height exceeding the design safety standard for semi-submersible barges, waters with sea ice and waters with rapidly decreasing air pressure need to be marked as dangerous.

[0044] The beneficial effects of the present invention are as follows: providing a long-distance transportation method for a semi-submersible barge immersed tube, comparing and selecting the optimal mooring point position through finite element analysis software, then determining the fatigue damage of the mooring cable and the required design bearing capacity through static balance analysis and dynamic effect analysis, considering the influence of the catenary, comparing the required mooring force when mooring cables of different materials and specifications reach the same design bearing capacity, selecting the mooring cable with the smallest mooring force as the optimal one, avoiding cracks in the immersed tube due to excessive local mooring force during transportation; and updating the route path in real time during navigation through the improved JPS algorithm, avoiding areas with poor weather conditions, navigation warning areas, ecological protection areas along the way, high-risk waters, legally restricted areas and areas with shallow reefs and submarine obstacles, thereby ensuring the safety of the transportation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a flow chart of transportation route planning of the method for long-distance transportation of immersed tubes by semi-submersible barge of the present invention;

[0046] Figure 2 It is a top view of the mooring arrangement of the method for long-distance transportation of immersed tubes by semi-submersible barge of the present invention;

[0047] Figure 3 It is a side view of the mooring arrangement of the method for long-distance transportation of immersed tubes by semi-submersible barge of the present invention;

[0048] Figure numerals: 1-semi-submersible barge, 2-immersed tube, 3-mooring cable. DETAILED DESCRIPTION

[0049] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments given here are only used to illustrate and explain the present invention and cannot be used to limit the present invention. It should be noted that many specific details are set forth in the following description to facilitate a full understanding of the present invention, but the present invention may also have other embodiments and variations thereof, and therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0050] The long-distance transportation method of the semi-submersible barge immersed tube in this embodiment includes finite element analysis of the immersed tube transportation process, mooring arrangement, transportation route planning, supporting facilities configuration, comprehensive transportation safety monitoring and emergency plan establishment. Among them, the mooring arrangement includes mooring point design, mooring cable selection, mooring cable weight determination and connection device design.

[0051] The mooring point design adopts multi-point mooring to improve stability. A mooring cable of any specification and material is selected, and finite element analysis software is used to simulate the stress conditions of the submerged tube under different mooring point layout schemes. The submerged tube has four corner points when viewed from above, and each corner point is arranged with a main force rope in both horizontal and vertical directions and an auxiliary force rope. The mooring point layout that makes the mooring force of the auxiliary force rope less than the mooring force of the main force rope and the mooring force of the main force rope is the smallest is selected as the optimal solution. The optimal solution must meet the requirements of symmetrical arrangement in the horizontal and vertical directions of the submerged tube.

[0052] The selection of mooring cables is firstly carried out through static balance analysis, which calculates the tension of each mooring cable in the static water state, taking into account the constant environmental loads, including the wind pressure load acting on the immersed tube.

[0053] P w =0.613C h C s v 2 (1)

[0054] Where P w - Wind pressure load of immersed tube, Pa, C h - Wind pressure height variation coefficient, C s - Wind load shape coefficient, v - wind speed at 10m above sea level, m / s; also includes the water flow resistance pressure acting on the immersed tube

[0055]

[0056] Where P wt - Water flow resistance pressure, Pa, ρ w - Water density, kg / m 3 , C w - water flow resistance coefficient, V-water flow velocity, m / s; the water flow velocity takes into account the towing speed of the semi-submersible barge and the natural sea current speed,

[0057] V=V s +Vc +V t (3)

[0058] Where V s -Semi-submersible barge towing speed, m / s, V c -Natural current speed, m / s, V t - The velocity of the water flow under the influence of tides in the nearshore area, m / s; the tension of the mooring cable is calculated, and the motion of the immersed tube under wave load is simulated using the JONSWAP wave spectrum, using time domain and frequency domain methods, considering the dynamic effects of waves and wind.

[0059]

[0060] In the formula, α is a dimensionless constant, x is the length of the wind zone, U is the wind speed, γ is the peak rise factor, the average value is 3.3, ω p - spectral peak frequency, σ-peak shape parameter;

[0061] α=0.076(gx / U 2 ) -0.22 (5)

[0062] ω p =22(g / U)(gx / U 2 ) -0.33 (6)

[0063]

[0064] The time-varying characteristics of the mooring cable tension are calculated using the general hydrodynamic analysis software. Based on the dynamic analysis results, the number of times n that the environmental conditions corresponding to each stress occur during the entire service life is calculated using Matlab compiled with the rainflow counting method SN curve and Miner linear cumulative damage theory. i From the SN curve, we can find the number of cycles N required to reach failure under this stress. i , and then calculate the n caused by each environmental condition i / N i Finally, the value of the mooring cable in one year ∑n is calculated by Miner linear cumulative damage theory i / N i , the fatigue life of the mooring cable can be calculated by formula (8):

[0065]

[0066] The required immersed tube tension of the mooring cable under the maximum design wind speed and the maximum design water flow velocity is calculated, and the sum of the required immersed tube tension and the pre-tension required for the stability of the immersed tube is taken as the design bearing capacity of the mooring cable. The strength, elastic modulus, corrosion resistance and fatigue life of the material are taken into consideration to determine the available mooring cable materials and specifications.

[0067] The weight of the mooring cable is determined, the influence of the catenary under the gravity and water resistance of the mooring cable is considered, and the water resistance of mooring cables of different materials is calculated.

[0068]

[0069] In the formula, F D - Mooring line water resistance, N, C D -Drag coefficient, depends on the shape of the mooring line, surface roughness and the Reynolds number of the water flow, A-projected surface area of ​​the mooring line facing the water, m 2 ; Calculate the resultant force of the mooring line water resistance and the mooring line gravity,

[0070]

[0071] In the formula, F G - the resultant force of the water resistance and gravity of the mooring cable, N, G-the gravity of the mooring cable, N; when the mooring cable with the smallest resultant force reaches the same design bearing capacity, the required mooring force is the smallest, and the mooring cable corresponding to the smallest mooring force is used;

[0072] Design of connection devices: design reliable connection devices between mooring cables and immersed tubes and semi-submersible barges, and conduct fatigue analysis and ultimate strength verification;

[0073] The transportation route planning specifically includes the following steps:

[0074] S101. Collect data;

[0075] Collect the throughput capacity of all ports between the starting point and the end point, the water depth of the ports, the berthing fees and other additional costs of the ports to determine whether the ports can provide necessary services such as loading and unloading, maintenance and replenishment;

[0076] S102, preliminary selection of routes;

[0077] Use the latest nautical chart data to identify feasible waterways, select ports that can be berthed according to the port's throughput capacity, the port's water depth and whether the port can provide necessary services, obtain weather forecasts along the way, including wind speed and wave height, obtain ship traffic along the way, and avoid bad weather and congested feasible waterways; obtain navigation warning area warnings, International Convention for the Prevention of Pollution from Ships areas, port data and maritime safety information, exclude the above areas from the feasible waterways, and obtain the preliminary route;

[0078] S103, cost-benefit analysis;

[0079] The cost-benefit analysis includes calculating the sailing time of each route according to the preliminary route, estimating the fuel consumption according to the sailing speed and distance, evaluating the berthing and other costs of each port of the preliminary route, obtaining the total cost of each route, and selecting the scheduled route with the best cost;

[0080] S104, Risk assessment;

[0081] The risk assessment includes the formulation of emergency plans to deal with possible mechanical failures, damage to immersed tubes, severe weather, shoals and reefs, ship collisions, pirate activities and entry into special areas during the shipping process, and continuous monitoring of weather changes on the scheduled route and monitoring of the safety of the waterway;

[0082] S105, real-time path optimization;

[0083] The real-time optimization of the path includes dividing the global map based on the Web Mercator projection into grids, with the ratio of the grid length to the actual distance being R, and obtaining in real time important information within a range of L nautical miles around the semi-submersible barge as the center, wherein the important information includes meteorological data, the latest navigation warning area information, ecological protection area information along the way, high-risk water area information, legally restricted area information, and shoal and reef seabed obstacle information. The meteorological data includes air pressure, wind speed, wind direction, visibility, precipitation, wave currents, sea fog, and ice condition reports, wherein grids corresponding to waters with wind speeds greater than the maximum design wind speed, waters with visibility less than 1 nautical mile, waters with wave heights exceeding the design safety standard of the semi-submersible barge, waters with sea ice, and waters with rapidly decreasing air pressure need to be marked as dangerous, and information on shoal and reef seabed obstacles is obtained using a multi-beam bathymetric system and a side-scan sonar, and a high-precision seabed topographic map is drawn, and grids corresponding to the areas involved in the important information in the global map are marked as dangerous, and when the grids marked as dangerous appear within the range, the improved JPS algorithm is used to update the local path to avoid the dangerous area;

[0084] S106, Record and Feedback;

[0085] After each flight segment is completed, the important information collected in real time is recorded and saved, the actual navigation route is compared with the planned route, the deviation position is found, and a review is performed to form a case database.

[0086] The improved JPS algorithm in this embodiment includes defining a starting point and a target point, setting an initial value of the time dimension, adding known dynamic obstacle trajectory information to the search space, using Manhattan distance as a heuristic function, and using the canonical order of V HW to generate a path; starting from the starting point, expanding nodes in VHW order, for each possible movement, checking whether there is a time obstacle, if so, recording it and waiting at an appropriate time, if there is no obstacle, continuing to expand until the target point is found or all possible paths are explored, and outputting the optimal path finally found.

[0087] In summary, the long-distance transportation method of the semi-submersible barge immersed tube of the present invention optimizes the mooring arrangement in the field of semi-submersible barge transportation, avoids cracks in the immersed tube due to excessive local mooring force during transportation, and ensures the transportation safety during the navigation of the semi-submersible barge.

[0088] It should be understood that the above-mentioned embodiments are one or more embodiments of the present invention, and there are many other embodiments and variations thereof based on the present invention; the variations and modifications made by ordinary technicians in this industry through the present invention without making pioneering innovations all fall within the scope of protection of the present invention.

Claims

1. A method for long-distance transportation of semi-submersible barge immersed tubes, including finite element analysis of immersed tube transportation process, mooring arrangement, transportation route planning, supporting facilities configuration, comprehensive transportation safety monitoring and emergency plan establishment, characterized by: The mooring arrangement includes the design of mooring points, the selection of mooring lines, the determination of mooring line weights and the design of connection devices; The mooring point design adopts multi-point mooring to improve stability, and uses finite element analysis software to simulate the stress conditions of the submerged pipe under different mooring point layout schemes to select the optimal scheme; The mooring cable selection firstly performs a static balance analysis to calculate the tension of each mooring cable in the static water state, and considers the constant environmental load to calculate the tension of the mooring cable. The time-varying characteristics of the mooring cable tension are calculated by using time domain and frequency domain methods and considering the dynamic effects of waves and wind. Based on the dynamic analysis results, the fatigue damage of the mooring cable during long-term use is evaluated, the fatigue life of the mooring cable is calculated, and the required immersed tube tension of the mooring cable under the maximum design wind speed and the maximum design water flow velocity is calculated. The sum of the required immersed tube tension and the pre-tension required for the stability of the immersed tube is used as the design bearing capacity of the mooring cable. Considering the strength, elastic modulus, corrosion resistance and fatigue life of the material, the available mooring cable materials and specifications are determined; The weight of the mooring cable is determined by considering the influence of the catenary under the gravity of the mooring cable and the water resistance, comparing the mooring forces of the mooring cables when the mooring cables of different weights are available to achieve the same design bearing capacity, and using the mooring cable corresponding to the minimum mooring force; The connection device design includes designing reliable connection devices between the mooring cable and the immersed tube and semi-submersible barge, and performing fatigue analysis and ultimate strength verification; The transportation route planning specifically includes the following steps: S101. Collect data; The data collection includes collecting the throughput capacity of all ports between the starting point and the end point, the water depth of the ports, the berthing fees and other additional charges of the ports, so as to determine whether the ports can provide the necessary services; S102, preliminary selection of routes; The preliminary route selection includes using the latest nautical chart data to identify feasible waterways, selecting ports that can be berthed according to the throughput capacity of the ports, the water depth of the ports and whether the ports can provide necessary services, obtaining weather forecasts along the way, including wind speed and wave height, obtaining ship traffic along the way, and avoiding bad weather and congested feasible waterways; obtaining navigation warning area warnings, International Convention for the Prevention of Pollution from Ships areas, port data and maritime safety information, excluding the above-mentioned areas from the feasible waterways, and obtaining the preliminary route; S103, cost-benefit analysis; The cost-benefit analysis includes calculating the sailing time of each route according to the preliminary route, estimating the fuel consumption according to the sailing speed and distance, evaluating the berthing and other costs of each port of the preliminary route, obtaining the total cost of each route, and selecting the scheduled route with the best cost; S104, Risk assessment; The risk assessment includes the formulation of emergency plans to deal with possible mechanical failures, damage to immersed tubes, severe weather, shoals and reefs, ship collisions, pirate activities and entry into special areas during the shipping process, and continuous monitoring of weather changes on the scheduled route and monitoring of the safety of the waterway; S105, real-time path optimization; The real-time optimization of the path includes dividing the global map based on the Web Mercator projection into grids, with the ratio of the grid length to the actual distance being R, and obtaining important information within a range of L nautical miles around the semi-submersible barge in real time, wherein the important information includes meteorological data, the latest navigation warning area information, ecological protection area information along the way, high-risk water area information, legally restricted area information, and shoal, reef, and seabed obstacle information; marking the grids corresponding to the areas involved in the important information in the global map as dangerous; and when the grids with the dangerous marking appear within the range, using the improved JPS algorithm to update the local path to avoid the dangerous area; S106, Record and Feedback; After each flight segment is completed, the important information collected in real time is recorded and saved, the actual navigation route is compared with the planned route, the deviation position is found, and a review is performed to form a case database.

2. The long-distance transportation method of a semi-submersible barge submerged pipe according to claim 1 is characterized by: The mooring point arrangement scheme must meet the requirements of symmetrical arrangement in the horizontal and vertical directions of the immersed tube.

3. The long-distance transportation method of a semi-submersible barge submerged pipe according to claim 1 is characterized by: The constant environmental load includes the wind pressure load acting on the immersed tube, P w =0.613C h C s v 2 (1) Where P w - Wind pressure load of immersed tube, Pa, C h - Wind pressure height variation coefficient, C s - Wind load shape coefficient, v - wind speed at 10m above sea level, m / s; also includes the water flow resistance pressure acting on the immersed tube Where P wt - Water flow resistance pressure, Pa, ρ w - Water density, kg / m 3 , C w - water flow resistance coefficient, V-water flow velocity, m / s; the water flow velocity takes into account the towing speed of the semi-submersible barge and the natural sea current speed, V=V s +V c +V t (3) Where V s -Semi-submersible barge towing speed, m / s, V c -Natural current speed, m / s, V t - Flow velocity of water under the influence of tides in nearshore areas, m / s.

4. The long-distance transportation method of a semi-submersible barge submerged pipe according to claim 1 is characterized by: During the analysis of the dynamic effects of waves and wind, the JONSWAP wave spectrum was used to simulate the movement of the immersed tube under the action of wave loads. Where, α is the dimensionless constant; x is the length of the wind zone, m; U is the wind speed, m / s; γ is the peak rise factor; ω is p - spectral peak frequency, Hz; σ-peak shape parameter.

5. The long-distance transportation method of a semi-submersible barge submerged pipe according to claim 1 is characterized by: The catenary effect includes calculation of the water resistance of mooring lines of different materials, In the formula, F D - Mooring line water resistance, N, C D -Drag coefficient, depends on the shape of the mooring line, surface roughness and the Reynolds number of the water flow, A-projected surface area of ​​the mooring line facing the water, m 2 ; Calculate the resultant force of the mooring line water resistance and the mooring line weight, In the formula, F G - the resultant force of the water resistance and gravity of the mooring cable, N, G - the gravity of the mooring cable, N; when the mooring cable with the smallest resultant force reaches the same design bearing capacity, the required mooring force is the smallest.

6. The long-distance transportation method of a semi-submersible barge submerged pipe according to claim 1 is characterized by: In step S105, the information of the shoal and reef seabed obstacles is acquired using a multi-beam bathymetric system and a side-scan sonar, and a high-precision seabed topographic map is drawn.

7. The long-distance transportation method of a semi-submersible barge submerged pipe according to claim 1 is characterized by: In step S105, the improved JPS algorithm includes defining a starting point and a target point, setting an initial value of the time dimension, adding known dynamic obstacle trajectory information to the search space, using Manhattan distance as a heuristic function, and using the canonical order of VHW to generate a path; starting from the starting point, expanding nodes in VHW order, for each possible movement, checking whether there is a time obstacle, if so, recording it and waiting at an appropriate time, if there is no obstacle, continuing to expand until the target point is found or all possible paths are explored, and outputting the optimal path finally found.

8. The long-distance transportation method of a semi-submersible barge submerged pipe according to claim 1 is characterized by: In step S105, the meteorological data includes air pressure, wind speed, wind direction, visibility, precipitation, waves and currents, sea fog and ice conditions reports, among which the grids corresponding to waters with wind speeds greater than the maximum design wind speed, waters with visibility less than 1 nautical mile, waters with wave heights exceeding the design safety standards for semi-submersible barges, waters with sea ice, and waters with rapidly decreasing air pressure need to be marked as dangerous.

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