Simulation and prediction method for dumping disposal condition of dredged soil

Abstract

The invention discloses a dredged soil dumping disposal condition simulation and prediction method. The method comprises the following steps: collecting and sorting parameter information; a dumping area hydrodynamic numerical model is established, and numerical simulation is conducted on the characteristic wave and tidal current flow field conditions; establishing a ship three-dimensional model, establishing a ship motion response model under the hydrodynamic condition by combining with numerical simulation results of waves and flow fields, calculating the motion condition of an operation ship under the action of waves and tidal currents, and performing simulation prediction on the sediment source intensity position and the motion condition in the dredged soil dumping operation process; building a sediment movement numerical model in the dredged soil underwater deposition and transportation process by using the parameter information and combining a hydrodynamic numerical model and a ship movement response model, and performing deposition and transportation prediction on the dredged soil poured into water; and analyzing a calculation result of the sediment movement numerical model to obtain a deposition transportation rule of the dredged soil. By means of the method, prediction of underwater sediment movement and the accumulation form of the underwater sediment is closer to the reality, and guidance is provided for dredged soil dumping operation.

Description

Technical Field

[0001] The invention belongs to the technical field of dredging engineering, and in particular relates to a method for simulating and predicting the dumping and disposal of dredged soil. Background Art

[0002] In recent years, a large amount of dredged soil has been disposed of mainly by ocean dumping using suction hopper dredgers.

[0003] With the increasing requirements for environmental protection and engineering design, the dumping of dredged soil (sediment) also needs to be refined accordingly. Currently, there have been many studies on the conventional movement of sediment in rivers, lakes, oceans and other waters. However, at this stage, there are still few in-depth studies on the movement process of sediment generated by waterway dredging projects during dumping and disposal. Due to the lack of quantitative analysis methods for the sediment dumping process, it is impossible to determine the amount of sediment deposited and the sedimentary form after dumping, which restricts the quantitative evaluation of dumping areas and dumping projects. Due to the lack of relevant research on the influence of control parameters on the dumping of dredged soil by hopper-type suction dredgers, the dumping construction process is often based on experience, making it impossible to optimize and guide the dumping project of hopper-type suction dredgers. In addition, after the dredged soil is deposited, a localized pile of sand will be formed. Currently, there is not much research on the laws of sediment movement and sedimentary form changes in the dumping area. The selection of the location for ship dumping of dredged soil and the strength of the dredged soil dumping mostly relies on experience, which is somewhat blind. Summary of the Invention

[0004] The present invention is made to solve the above problems and aims to provide a method for simulating and predicting the dumping and disposal of dredged soil.

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

[0006] A method for simulating and predicting dredged soil dumping and disposal conditions, comprising:

[0007] Step S1: collecting and arranging dredged soil and sediment parameter information, dumping area environmental parameter information, operating vessel parameter information, and engineering construction parameter information;

[0008] Step S2: establishing a hydrodynamic numerical model of the dumping area based on the environmental parameter information of the dumping area, and performing numerical simulation on the characteristic waves and tidal flow field of the dumping area;

[0009] Step S3: Building a three-dimensional model of the vessel based on the parameter information of the operating vessel. Combined with the numerical simulation results of the characteristic waves and tidal flow fields in the dumping area, CFD software is used to build a ship motion response model under the hydrodynamic conditions of the dumping area. The motion of the operating vessel under the action of waves and tidal currents is calculated, and the location and motion of the sediment source during the dredged soil dumping operation are simulated and predicted.

[0010] Step S4: Using the dredged soil and sediment parameter information and the engineering construction parameter information, combined with the hydrodynamic numerical model and the ship motion response model, a sediment movement numerical model for the underwater deposition and transport process of the dredged soil is further established to predict the deposition and transport of the dredged soil dumped into the water;

[0011] Step S5: Analyze the calculation results of the sediment movement numerical model through post-processing software to obtain the deposition and transportation law of the dredged soil dumped into the water.

[0012] Furthermore, in step S1, the dredged soil and sediment parameter information includes sediment particle grading, density, starting flow velocity, and sedimentation velocity; the dumping area environmental parameter information includes underwater topography, water depth, bottom roughness, historical tide level, and sea surface wind speed; the operating vessel parameter information includes ship lines, ship size, and draft depth; and the engineering construction parameter information includes dredged soil dumping location, dredged soil dumping volume, and dredged soil dumping rate.

[0013] Furthermore, in step S2, the computational domain is meshed using hydrodynamic numerical simulation software, and a hydrodynamic numerical model is established by inputting environmental parameter information of the dumping area to obtain numerical simulation results of characteristic waves and tidal flow fields in the dumping area.

[0014] In the hydrodynamic numerical model, the basic governing equation of water motion is:

[0015]

[0016] Where h is the water depth; x, y, and t are the coordinate axes and time of the Cartesian coordinate system; u and v are the velocity components of the fluid in the x and y directions in the Cartesian coordinate system, respectively; ρ is the fluid density; E is the eddy viscosity coefficient of the fluid; g is the gravitational acceleration; a is the bottom elevation; n is the Manning coefficient; τ wx and τ wy are the wind stress components in the x and y directions respectively; f is the Coriolis force coefficient, f = 2ΩsinФ, Ω is the angular velocity of the earth's rotation, and Ф is the local latitude of the computational domain;

[0017] The basic governing equations for waves are:

[0018]

[0019] Where N(δ,θ) is the wave action density, e(δ,θ) is the wave energy spectrum density, δ is the relative angular frequency, and θ is the wave direction.

[0020] Furthermore, in step S3, the numerical simulation results of the characteristic waves and tidal flow fields are used as boundary input parameters of the ship motion response model, and the CFD software is used to build a ship motion response model of the dumping area operating ship under hydrodynamic conditions. The computer is used to calculate and simulate the motion of the operating ship under the action of waves and tidal currents, including transverse, longitudinal and vertical motion forms. Based on the calculation simulation results of the ship motion response model and combined with the relative position of the dredged soil dumping outlet and the operating ship, the change of the position of the dredged soil dumping outlet with the wave and tidal current under the action of waves is determined, and the sediment source strength position and sediment movement during the dredged soil dumping operation are simulated and predicted.

[0021] Furthermore, in step S3, when establishing the ship motion response model using CFD software, water is regarded as an incompressible viscous fluid, and the expressions for conservation of mass and momentum are:

[0022]

[0023] Where V F is the volume fraction of the flowing fluid, u, v, and w are the velocity components of the fluid in the x, y, and z directions respectively, and A X 、A Y 、A Z are the area fractions of the flowable fluid in the x, y, and z directions in the spatial coordinate system, ρ is the fluid density, p is the pressure acting on the microelement, g is the acceleration of gravity, and fx, fy, and fz are the viscous accelerations in the x, y, and z directions, respectively.

[0024] The motion control equation of the operating ship is:

[0025]

[0026] Where V P represents the velocity of any point P on the operating vessel, V G represents the velocity of the center point G of the operating vessel, ω represents the angular velocity of the operating vessel, r P / G represents the vector length from point G to point P; F represents the resultant force acting on the operating vessel, m represents the mass of the operating vessel, T G represents the total torque acting on point G, and [J] represents the instantaneous inertia tensor of the operating ship system.

[0027] Furthermore, in step S4, the ship motion conditions obtained through the ship motion response model are used as input conditions for the motion trajectory of the dredged soil dumping outlet position in the sediment motion numerical model to simulate the motion conditions of the actual dredged soil dumping outlet position under the action of waves and currents; the dredged soil and sediment parameter information is used as the sediment setting condition, and the engineering construction parameter information is used as the dredged soil source strength setting during the dredged soil dumping process; the numerical simulation results of waves and tidal currents in the dumping area are used as the hydrodynamic conditions of the dumping area, and the sediment transport equation is used to simulate the movement process of sediment under hydrodynamic conditions, including the sedimentation, resuspension, and diffusion processes of sediment, to determine the sediment movement characteristics during the dredged soil dumping operation under the influence of actual sea conditions.

[0028] Furthermore, in step S4, when establishing the sediment transport equation, the sediment movement during the dredged soil dumping operation is calculated in the form of suspended load and bed load, wherein the sediment transport formula of bed load is: Where, subscript i corresponds to the sediment of type i particle size, q b,i is the bed load transport rate of sediment of the i-th particle size, Ф i is the bed load transport coefficient; ∥g∥ is the value of gravitational acceleration; ρ i is the density of sediment; ρ is the fluid density; d i is the median particle size; the governing equation for suspended matter is the convection-diffusion equation, namely: Where C s,i is the mass concentration of suspended sediment; D is the sediment diffusion coefficient; u s,i is the suspended sediment velocity.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The simulation and prediction method for dredged soil dumping and disposal of the present invention comprehensively considers the influence of the hydrodynamic environment of the dumping area, the movement of the dumping construction vessel, and the intensity of the dredged soil dumping operation. It can accurately analyze the sediment deposition and transport patterns during the process of dredged soil dumping by the operating vessel, and provide a reference for optimizing the dredged soil dumping treatment plan for offshore dredging projects.

[0031] 2. The simulation and prediction method for the dumping and disposal of dredged soil of the present invention combines a large-scale hydrodynamic numerical model of the dumping area with a small-scale three-dimensional model of the ship, solving the problem that the deposition and transport of dredged soil cannot be accurately predicted because the ship is always in motion during the dumping of dredged soil in the dumping area under the influence of the hydrodynamic environment. This method can make the prediction of sediment movement and its accumulation form during the underwater dumping of dredged soil closer to reality, and provide guidance for dredging ships to dump dredged soil in offshore dumping areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1is a flow chart of the method for simulating and predicting the dumping and disposal of dredged soil according to the present invention;

[0033] Figure 2 This is a schematic diagram of the engineering area in Example 2;

[0034] Figure 3a-3b Schematic diagram of the numerical simulation results of the hydrodynamics of the dumping area in Example 2;

[0035] Figure 4 This is a three-dimensional model diagram of the operating vessel in Example 2;

[0036] Figure 5 2 is a schematic diagram of the numerical simulation results of the underwater dumping of dredged soil in Example 2;

[0037] Figure 6 Schematic diagram of the post-processing analysis results in Example 2. DETAILED DESCRIPTION

[0038] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the following embodiments and accompanying drawings specifically illustrate the method for simulating and predicting the dumping and disposal of dredged soil of the present invention.

[0039] Example 1

[0040] like Figure 1 As shown, this embodiment provides a method for simulating and predicting the disposal of dredged soil, including:

[0041] Step S1: collecting and arranging dredged soil and sediment parameter information, dumping area environmental parameter information, operating vessel parameter information, and engineering construction parameter information;

[0042] Step S2: establishing a hydrodynamic numerical model of the dumping area based on the environmental parameter information of the dumping area collected in step S1, and numerically simulating the characteristic waves and tidal flow field of the dumping area;

[0043] Step S3: Based on the parameter information of the operating vessel collected in step S1, a three-dimensional model of the vessel is established. Combined with the numerical simulation results of the characteristic waves and tidal flow fields in the dumping area in step S2, a ship motion response model under the hydrodynamic conditions of the dumping area is established using CFD software. The motion of the operating vessel under the action of waves and tidal currents is calculated, and the location and motion of the sediment source during the dredged soil dumping operation are simulated and predicted.

[0044] Step S4: Using the dredged soil and sediment parameter information and engineering construction parameter information collected in step S1, combined with the hydrodynamic numerical model of step S2 and the ship motion response model of step S3, a sediment movement numerical model of the underwater deposition and transport process of the dredged soil is further established to predict the deposition and transport of the dredged soil dumped into the water;

[0045] Step S5: Analyze the calculation results of the sediment movement numerical model through post-processing software to obtain the deposition and transportation law of the dredged soil dumped into the water.

[0046] Specifically, in step S1, dredged soil and sediment parameter information includes sediment particle size distribution, density, starting velocity, and settling velocity; dumping area environmental parameter information includes underwater topography, water depth, bottom roughness, historical tide levels, and sea surface wind speed; operating vessel parameter information includes vessel lines, vessel dimensions, and draft; and construction parameter information includes dredged soil dumping location, dredged soil dumping volume, and dredged soil dumping rate. The bottom roughness parameter is related to bed sediment characteristics, water depth, and topography. The value of the bottom roughness parameter can be determined by combining the range of Manning's coefficient values from similar studies and debugging based on actual site conditions.

[0047] After collecting dredged soil and sediment parameters, dumping area environmental parameters, operating vessel parameters, and engineering construction parameters, all data is collated and processed to meet the needs of subsequent numerical simulations. Data processing specifically involves data cleaning and data format conversion to ensure data quality and usability, providing a reliable data foundation for subsequent numerical simulations.

[0048] Furthermore, in step S2, the calculation domain is gridded using hydrodynamic numerical simulation software, and a hydrodynamic numerical model is established by inputting environmental parameter information of the dumping area to obtain numerical simulation results of characteristic waves and tidal flow fields of the dumping area.

[0049] In the hydrodynamic numerical model, the basic governing equation of water motion is:

[0050]

[0051] Where h is the water depth; x, y, and t are the coordinate axes and time of the Cartesian coordinate system; u and v are the velocity components of the fluid in the x and y directions in the Cartesian coordinate system, respectively; ρ is the fluid density; E is the eddy viscosity coefficient of the fluid; g is the gravitational acceleration; a is the bottom elevation; n is the Manning coefficient; τ wx and τ wy are the wind stress components in the x and y directions respectively; f is the Coriolis coefficient, f = 2ΩsinФ, Ω is the angular velocity of the earth's rotation, and Ф is the local latitude of the calculation domain.

[0052] The basic governing equations for waves are:

[0053]

[0054] Where N(δ,θ) is the wave action density, e(δ,θ) is the wave energy spectrum density, δ is the relative angular frequency, and θ is the wave direction.

[0055] Furthermore, in step S3, the numerical simulation results of the characteristic wave and tidal flow fields obtained in step S2 are used as boundary input parameters of the ship motion response model. CFD software is used to construct a ship motion response model of the vessel operating in the dumping area under hydrodynamic conditions. The motion of the vessel under the influence of waves and tidal currents is simulated using a computer. This includes sway, surge, and heave. Based on the simulation results of the ship motion response model and the relative position of the dredged soil dumping outlet and the operating vessel, the position of the dredged soil dumping outlet changes with the influence of waves and tidal currents, and the sediment source intensity location and sediment movement during the dredged soil dumping operation are simulated and predicted.

[0056] Specifically, when using CFD software to establish a ship motion response model, water is regarded as an incompressible viscous fluid, and the expressions for conservation of mass and momentum are:

[0057]

[0058] Where V F is the volume fraction of the flowing fluid, u, v, and w are the velocity components of the fluid in the x, y, and z directions respectively, and A X 、A Y 、A Z are the area fractions of the flowable fluid in the x, y, and z directions in the spatial coordinate system, ρ is the fluid density, p is the pressure acting on the microelement, g is the acceleration of gravity, and fx, fy, and fz are the viscous accelerations in the x, y, and z directions, respectively.

[0059] The motion control equation of the operating ship is:

[0060]

[0061] Where V P represents the velocity of any point P on the operating vessel, V G represents the velocity of the center point G of the operating vessel, ω represents the angular velocity of the operating vessel, r P / G represents the vector length from point G to point P; F represents the resultant force acting on the operating vessel, m represents the mass of the operating vessel, T G represents the total torque acting on point G, and [J] represents the instantaneous inertia tensor of the operating ship system.

[0062] Furthermore, in step S4, the ship motion conditions obtained through the ship motion response model are used as input conditions for the motion trajectory of the dredged soil dumping outlet position in the sediment motion numerical model, simulating the actual motion of the dredged soil dumping outlet position under the action of waves and currents. Dredged soil and sediment parameter information is used as the sediment setting condition, and the engineering construction parameter information is used as the dredged soil source intensity setting during the dredged soil dumping process. The numerical simulation results of waves and tidal currents in the dumping area are used as the hydrodynamic conditions of the dumping area. The sediment transport equation is used to simulate the movement process of sediment under hydrodynamic conditions, taking into account the sedimentation, resuspension, diffusion and other processes of sediment, and determining the sediment movement characteristics during the dredged soil dumping operation under the influence of actual sea conditions.

[0063] Specifically, when establishing the sediment transport equation, the sediment movement during the dredged soil dumping operation is mainly calculated in the form of suspended load and bedload. The movement of sediment is estimated by predicting the erosion, advection and deposition of sediment. It is determined by the suspended load, the sediment settling caused by gravity, the sediment entrainment caused by riverbed shear and water disturbance, and the bedload transport (i.e., the rolling, jumping or sliding of sediment particles along the filled riverbed). The bedload transport formula is: Where, subscript i corresponds to the sediment of type i particle size, q b,i is the bed load transport rate of sediment of the i-th particle size, Ф i is the bed load transport coefficient; ∥g∥ is the value of gravitational acceleration; ρ i is the density of sediment; ρ is the fluid density; d i is the median particle size. The governing equation for suspended matter is the convection-diffusion equation, namely: Where C s,i is the mass concentration of suspended sediment; D is the sediment diffusion coefficient; u s,i is the suspended sediment velocity.

[0064] Furthermore, in step S5, the calculation results of the numerical model are analyzed by post-processing software to obtain the deposition and transport rules of the dumped dredged soil, which provides technical support for subsequent dredging projects and helps to predict the diffusion range of sediment during the dredged soil dumping process.

[0065] When it is necessary to carry out dredged soil dumping operations in areas with high environmental protection requirements, the above steps can be used to obtain the deposition, transport and diffusion patterns of dredged soil during the dumping process according to the actual project situation. On this basis, a construction plan can be formulated or optimized, and appropriate wave and tidal conditions can be selected to carry out dredged soil dumping operations. At the same time, the mud gate opening can be adjusted to control parameters such as the mud unloading speed, so that the mud and sand diffusion range during the dumping process can meet environmental protection requirements and reduce the impact of the dumping construction on the environment.

[0066] Example 2

[0067] On the basis of Example 1, this example takes a waterway dredged soil dumping project in a typical domestic estuary area as an example to further illustrate the simulation and prediction method for dredged soil dumping disposal of the present invention.

[0068] The construction area of this embodiment is as follows: Figure 2 As shown in the figure, the dredged soil is mainly composed of silt.

[0069] First, in step S1, dredged soil and sediment parameter information, dumping area environmental parameter information, operating vessel parameter information, and engineering construction parameter information are collected and organized. The collected dumping area environmental parameter information is organized and analyzed, and the data format is modified to meet the data requirements for establishing the dumping area hydrodynamic numerical model.

[0070] In step S2, the computational domain is meshed using ocean hydrodynamic numerical simulation software. By inputting environmental parameter information of the dumping area, including the water depth, topography, sea surface wind field, tide level, bottom roughness, etc., a hydrodynamic numerical model of the dumping area is established, and the characteristic wave and tidal flow fields of the dumping point in the dumping area are calculated. The results are as follows: Figure 3a-3b As shown (taking the data of a certain day as an example). In this embodiment, the velocity of the rapid current in the dumping area during the spring tide is mostly around 2.5m / s, and can reach 3m / s in some areas. The highest velocity during the neap tide is about 1.5m / s, and the wave height is within 0.4m. The waves propagate southward, which is basically consistent with the wind direction.

[0071] In step S3, a three-dimensional model of the ship is established based on the operating ship parameter information, such as Figure 4 As shown, in this embodiment, the operating ship is selected as 10000m 3 A trailing suction hopper dredger has 10 mud gates (two in a row) on its bottom for mud dumping; each gate has a diameter of 4 meters. Combining the characteristic wave and tidal flow fields at the dumping point calculated in Step 2, CFD software was used to establish a ship motion response model under the hydrodynamic conditions of the dumping area. The motion of the operating vessel under the influence of waves and tidal currents was calculated, and the location and movement of sediment sources during the dredged soil dumping operation were simulated and predicted.

[0072] In step S4, the dredged soil and sediment parameter information and engineering construction parameter information collected in step S1 are used, combined with the hydrodynamic numerical model of step S2 and the ship motion response model of step S3, to further establish a sediment movement numerical model of the underwater deposition and transport process of dredged soil, and to predict the deposition and transport of dredged soil dumped into the water.

[0073] In this embodiment, the operation time of the fully loaded dumping operation of the operating vessel is usually 5 minutes, and the mud is unloaded simultaneously through 10 mud gates, and the overall unloading time is 300 seconds. Statistical analysis determined that the characteristic wave height during the mud unloading process is 0.4m, the tidal flow velocity is 1.5m / s, and the wave propagates southward. The characteristic wave and tidal flow field conditions calculated in step 2 are used as the hydrodynamic input conditions of the dumping area to simulate the sediment movement characteristics during the dredged soil dumping process under the influence of actual sea conditions. The results are as follows: Figure 5 shown.

[0074] Finally, in step S5, the calculation results of the sediment movement numerical model are analyzed by post-processing software, such as Figure 6 As shown in the figure, the deposition and transport law of dumped dredged soil is obtained, and the water diffusion concentration, maximum pile height and accumulation range during the dumping process are analyzed to provide a reference for subsequent dredged soil dumping operations.

[0075] The above embodiments are preferred examples of the present invention and are not intended to limit the scope of protection of the present invention.

Claims

1. A method for simulating and predicting the disposal of dredged soil, characterized in that: include: Step S1: collecting and arranging dredged soil and sediment parameter information, dumping area environmental parameter information, operating vessel parameter information, and engineering construction parameter information; Step S2: establishing a hydrodynamic numerical model of the dumping area based on the environmental parameter information of the dumping area, and performing numerical simulation on characteristic waves and tidal flow fields in the dumping area; Step S3: Based on the parameter information of the operating vessel, a three-dimensional model of the vessel is established. Combined with the numerical simulation results of the characteristic waves and tidal flow fields of the dumping area, a CFD software is used to establish a ship motion response model under the hydrodynamic conditions of the dumping area. The motion of the operating vessel under the action of waves and tidal currents is calculated, and the location and motion of the sediment source during the dredged soil dumping operation are simulated and predicted. Step S4: using the dredged soil and sediment parameter information and the engineering construction parameter information, combined with the hydrodynamic numerical model and the ship motion response model, further establishing a sediment movement numerical model for the underwater deposition and transport process of the dredged soil, and performing deposition and transport prediction for the dredged soil dumped into the water; Step S5: Analyze the calculation results of the sediment movement numerical model through post-processing software to obtain the deposition and transportation law of the dredged soil dumped into the water.

2. The method for simulating and predicting the disposal of dredged soil according to claim 1, characterized in that: In step S1, the dredged soil and sediment parameter information includes sediment particle gradation, density, starting flow velocity, and sedimentation velocity; the dumping area environmental parameter information includes underwater topography, water depth, bottom roughness, historical tide level, and sea surface wind speed; the operating vessel parameter information includes ship lines, ship size, and draft depth; and the engineering construction parameter information includes dredged soil dumping location, dredged soil dumping volume, and dredged soil dumping rate.

3. The method for simulating and predicting the disposal of dredged soil according to claim 1, characterized in that: In step S2, the computational domain is meshed using hydrodynamic numerical simulation software. By inputting environmental parameter information of the dumping area, a hydrodynamic numerical model is established to obtain numerical simulation results of the characteristic waves and tidal flow fields of the dumping area. In the hydrodynamic numerical model, the basic governing equation of water motion is: Where h is the water depth; x, y, and t are the coordinate axes and time of the Cartesian coordinate system; u and v are the velocity components of the fluid in the x and y directions in the Cartesian coordinate system, respectively; ρ is the fluid density; E is the eddy viscosity coefficient of the fluid; g is the gravitational acceleration; a is the bottom elevation; n is the Manning coefficient; τ wx and τ wy are the wind stress components in the x and y directions respectively; f is the Coriolis force coefficient, f = 2ΩsinФ, Ω is the angular velocity of the earth's rotation, and Ф is the local latitude of the computational domain; The basic governing equations for waves are: Where N(δ,θ) is the wave action density, e(δ,θ) is the wave energy spectrum density, δ is the relative angular frequency, and θ is the wave direction.

4. The method for simulating and predicting the disposal of dredged soil according to claim 1, wherein: In step S3, the numerical simulation results of the characteristic waves and tidal flow fields are used as the boundary input parameters of the ship motion response model, and the CFD software is used to build a ship motion response model of the dumping area operating ship under hydrodynamic conditions. The motion of the operating ship under the action of waves and tidal currents is simulated by computer calculation, including transverse, longitudinal and vertical motion forms. Based on the calculation simulation results of the ship motion response model and combined with the relative position of the dredged soil dumping outlet and the operating ship, the change of the position of the dredged soil dumping outlet with the wave and tidal current under the action of waves is determined, and the sediment source strength position and sediment movement during the dredged soil dumping operation are simulated and predicted.

5. The method for simulating and predicting the disposal of dredged soil according to claim 4, characterized in that: In step S3, when establishing the ship motion response model using CFD software, water is considered as an incompressible viscous fluid, and the expressions for conservation of mass and momentum are: Where V F is the volume fraction of the flowing fluid, u, v, and w are the velocity components of the fluid in the x, y, and z directions respectively, and A X 、A Y 、A Z are the area fractions of the flowable fluid in the x, y, and z directions in the spatial coordinate system, ρ is the fluid density, p is the pressure acting on the microelement, g is the acceleration of gravity, and fx, fy, and fz are the viscous accelerations in the x, y, and z directions, respectively. The motion control equation of the operating ship is: Where V P represents the velocity of any point P on the operating vessel, V G represents the velocity of the center point G of the operating vessel, ω represents the angular velocity of the operating vessel, r P / G represents the vector length from point G to point P; F represents the resultant force acting on the operating vessel, m represents the mass of the operating vessel, T G represents the total torque acting on point G, and [J] represents the instantaneous inertia tensor of the operating ship system.

6. The method for simulating and predicting the disposal of dredged soil according to claim 1, characterized in that: In step S4, the ship motion condition obtained by the ship motion response model is used as the input condition of the motion trajectory of the dredged soil dumping outlet position in the sediment motion numerical model to simulate the motion condition of the actual dredged soil dumping outlet position under the action of waves and currents; the dredged soil and sediment parameter information is used as the setting condition of sediment, and the engineering construction parameter information is used as the setting of the dredged soil source strength during the dredged soil dumping process; the numerical simulation results of waves and tidal currents in the dumping area are used as the hydrodynamic conditions of the dumping area, and the sediment transport equation is used to simulate the movement process of sediment under hydrodynamic conditions, including the sedimentation, resuspension and diffusion processes of sediment, to determine the sediment movement characteristics during the dredged soil dumping operation under the influence of actual sea conditions.

7. The method for simulating and predicting the dumping and disposal of dredged soil according to claim 6, characterized in that: In step S4, when establishing the sediment transport equation, the sediment movement during the dredged soil dumping operation is calculated in the form of suspended load and bedload. The sediment transport formula of bed load is: Where, subscript i corresponds to the sediment of type i particle size, q b,i is the bed load transport rate of sediment of the i-th particle size, Ф i is the bed load transport coefficient; ∥g∥ is the value of gravitational acceleration; ρ i is the density of sediment; ρ is the fluid density; d i is the median particle size; The governing equation for suspended matter is the convection-diffusion equation, namely: Where C s,i is the mass concentration of suspended sediment; D is the sediment diffusion coefficient; u s,i is the suspended sediment velocity.

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