An underwater sand curtain suitable for offshore construction and a method for laying the same

Abstract

The present application relates to the technical research field of offshore engineering construction, and particularly relates to an underwater sand curtain suitable for offshore construction and a laying method thereof, which forms a shelter for a protected sea area by using a flexible sand curtain, changes a near-bottom flow field, promotes the deposition of silt in seawater, and achieves the purpose of sand interception. In addition, compared with traditional construction of engineering measures such as submerged dike and ecological sand fixation, the sand curtain of this form can be processed and modularly assembled on land, and only needs to be thrown and laid by a construction ship during offshore construction, so that the construction speed is extremely fast, the construction cost is greatly reduced, and meanwhile, the planar layout of the sand curtain can be flexibly corrected according to the actual situation on site, so that the optimal sand interception effect is finally achieved, and the laying flexibility is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of offshore engineering construction, and particularly relates to an underwater sand curtain suitable for offshore construction and a laying method thereof. BACKGROUND

[0002] A submerged dike is a submerged dike structure constructed on the seabed, which changes the local flow dynamic conditions and reduces the sediment transport to the channel or harbor basin, thereby playing a role in preventing and reducing siltation. Although the submerged dike technology is relatively mature, there are still significant limitations. The initial investment of the submerged dike is relatively high (about 15-20 million yuan / km), especially for a channel several kilometers long, which often requires a huge investment for construction. Since the submerged dike is laid once, a large amount of experimental research needs to be carried out during the design stage to demonstrate the design parameters such as the layout, height and width of the submerged dike to ensure the effect of preventing and reducing siltation, otherwise it will cause huge investment losses. A large number of engineering practices show that due to the complex mechanism of sediment deposition, the intervention effect of artificial engineering scheme often cannot achieve the expected goal, thereby leading to huge investment in the field of port channel siltation prevention and reduction in China, but the effect is general. At the same time, with the increasing emphasis on marine environmental protection in China, it is often difficult to obtain the sea use approval in large-scale submerged dike construction projects, which also limits the application of this scheme.

[0003] At present, the prevention and reduction of siltation of ports and channels in China still mainly relies on regular dredging, and there is a large amount of dredging cost every year. Therefore, it is necessary to develop a low-cost, convenient-to-construct, non-interfering-channel-normal-navigation and small-environment-impact siltation prevention and reduction engineering measure. SUMMARY

[0004] The present application provides an underwater sand curtain suitable for offshore construction, which comprises a flexible curtain body module and an anchoring assembly, the anchoring assembly is connected to the seabed beach, and the bottom of the flexible curtain body module is connected to the anchoring assembly.

[0005] The flexible curtain body module comprises a plurality of flexible curtain bodies A, a float belt is connected to the top of the plurality of flexible curtain bodies A, the flexible curtain body A is a reinforced synthetic fiber geotextile, a plurality of longitudinal main cables A arranged in longitudinal direction and a plurality of transverse secondary cables A arranged in transverse direction are arranged on the flexible curtain body A, the transverse secondary cable A and the longitudinal main cable A form a grid structure for dispersing stress, the longitudinal main cable A is used for bearing the main tension of the flexible curtain body A, and the transverse secondary cable A is used for bearing the secondary tension of the flexible curtain body A.

[0006] The anchoring assembly comprises a seabed pile foundation A, a Hall anchor A and a connecting anchor cable A, the seabed pile foundation A and the Hall anchor A are both connected to the seabed beach, one end of the connecting anchor cable A is connected to the top of the seabed pile, and the other end of the connecting anchor cable A is connected to the float belt.

[0007] Further, the bottom of the flexible curtain body A is provided with a counterweight chain A, the counterweight chain A is tied at the bottom of the flexible curtain body A, and the counterweight chain A is linked with the Hall anchor A.

[0008] Further, the buoy belt includes a plurality of buoy units, and the buoy units are connected with each other through flexible cables.

[0009] Further, the height of the flexible curtain body A in the water depth direction is higher than the water depth corresponding to the highest seawater tide level.

[0010] A laying method of an underwater sand curtain suitable for offshore construction, comprising the following steps:

[0011] Step 1: analyzing the environmental characteristics of the sea area where the pile-anchor integrated underwater sand curtain is applied, to provide input conditions for the parameter design of the pile-anchor integrated underwater sand curtain, wherein the environmental characteristics of the sea area where the pile-anchor integrated underwater sand curtain is applied include the water depth of the channel side beach, the current velocity and the wave condition;

[0012] Step 2: determining the design parameters of the pile-anchor integrated underwater sand curtain based on the water depth of the channel side beach, the current velocity and the wave condition;

[0013] Step 3: comparing and selecting the design parameters of the pile-anchor integrated underwater sand curtain through physical model test, and determining the combination of the design parameters of the pile-anchor integrated underwater sand curtain through the physical model test;

[0014] Step 4: constructing the pile-anchor integrated underwater sand curtain according to the combination of the design parameters of the pile-anchor integrated underwater sand curtain, wherein the pile-anchor integrated underwater sand curtain comprises a flexible curtain body module and an anchoring assembly, the flexible curtain body module comprises a plurality of flexible curtain bodies A, and the anchoring assembly comprises a seabed pile foundation A, a Hall anchor A and a connecting anchor cable A;

[0015] Step 5: laying the seabed pile foundation A at intervals of 200m in the sea area, and connecting the buoy belt with the seabed pile foundation A by using the connecting anchor cable A;

[0016] Step 6: segmentally and synchronously laying the pile-anchor integrated underwater sand curtain with a total length of 20km, a single segment is 1km long, and 5 construction ships are arranged for laying, the single segment flexible curtain body module is loaded on the construction ship, after reaching the predetermined position, the construction ship slowly sails along the planned route, during which the flexible curtain body A-counterweight chain A-buoy belt-Hall anchor A combination is gradually thrown, and the connecting anchor cable A is connected with the flexible curtain body A at the position of the seabed pile foundation A, finally the laying of the pile-anchor integrated underwater sand curtain is completed.

[0017] Further, the physical model test on the design parameters of the pile-anchor integrated underwater sand curtain in step 3 includes: scaling the pile-anchor integrated underwater sand curtain according to a preset scale, applying wave and flow velocity in a wave and current test harbor, forming wave and current load on the flexible curtain module, and measuring the underwater water retaining height of the flexible curtain module by using a steel ruler.

[0018] Further, the pile-anchor integrated underwater sand curtain is scaled according to a model scale of 1:25, and the scaled sand curtain model is arranged in the wave and current test harbor.

[0019] Further, after the underwater water retaining height of the flexible curtain module is measured by using a steel ruler, 20 kg of model sand with a median particle size of 0.1 mm is weighed, and the model sand is uniformly thrown into the test water body at a position 5 meters upstream of the pile-anchor integrated underwater sand curtain model within 2 minutes. After 2 minutes of throwing, the flow and wave system is turned off, the bottom sediment upstream of the sand curtain module is weighed after drying, the sand retaining ratio is calculated, and the sand retaining effect of the pile-anchor integrated underwater sand curtain is verified according to the sand retaining ratio.

[0020] The underwater sand curtain suitable for offshore construction has the following advantages:

[0021] The underwater sand curtain provided by the present application is used for forming a shelter for a protected sea area, changing a near-bottom flow field, promoting sediment deposition in seawater, and achieving the purpose of sand retaining. In addition, compared with traditional submerged dike and ecological sand retaining engineering measures, the sand curtain can be processed and modularly assembled on land, and only needs to be thrown into the sea during offshore construction, so that the construction speed is extremely fast, the construction cost is greatly reduced, the sand curtain layout can be flexibly corrected according to the actual situation on site, and the optimal sand retaining effect is finally achieved. DETAILED DESCRIPTION

[0022] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative labor.

[0023] Figure 1 The structure of the underwater sand curtain suitable for offshore construction is shown in the figure.

[0024] Figure 2 The load transmission of the integrated underwater sand curtain is shown in the figure.

[0025] Figure 3 The force analysis of the float belt A is shown in the figure.

[0026] Figure 4 Fig. 1 is a schematic diagram of a force analysis of a flexible curtain A.

[0027] Figure 5 Fig. 2 is a schematic diagram of a relationship between flow velocity and water blocking ratio of a partial sand blocking curtain test data.

[0028] Figure 6 Fig. 3 is a schematic diagram of a sand blocking curtain structure in an embodiment 2 of the present application.

[0029] Figure 7 Fig. 4 is a schematic diagram of a load transmission of a flexible curtain B in the embodiment 2 of the present application.

[0030] Figure 8 Fig. 5 is a schematic diagram of a sand blocking curtain structure in an embodiment 3 of the present application.

[0031] Figure 9 Fig. 6 is a schematic diagram of an enlarged structure of a longitudinal main cable B in the embodiment 3 of the present application.

[0032] Figure 10 Fig. 7 is a schematic diagram of an enlarged structure of a Hall anchor C in the embodiment 3 of the present application.

[0033] Wherein:

[0034] 1, flexible curtain A; 2, pontoon belt A; 3, connecting anchor cable A;

[0035] 4, transverse secondary cable A; 5, longitudinal main cable A; 6, submarine pile foundation A;

[0036] 7, counterweight iron chain A; 8, Hall anchor A; 9, pontoon belt B;

[0037] 10, submarine pile foundation B; 11, counterweight iron chain B; 12, Hall anchor B;

[0038] 13, flexible curtain B; 14, mooring chain; 15, connecting anchor cable B;

[0039] 16, pontoon belt C; 17, flexible curtain C; 18, longitudinal main cable B;

[0040] 181, connecting piece; 19, transverse secondary cable B; 20, pontoon belt D;

[0041] 21, connecting anchor cable C; 22, counterweight iron chain C; 23, Hall anchor C;

[0042] 231, anchor tip; 232, bearing piece; 233, connecting chain;

[0043] 234, assembly piece; 235, connecting shaft; 24, submarine pile foundation C. DETAILED DESCRIPTION

[0044] The technical solutions of the present application will be described clearly and completely in combination with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0045] Embodiment 1: The underwater sand curtain proposed in the present application can achieve the effect of silt reduction and protection of the approach channel at a low cost. The specific implementation process is as follows: first, analyze the environmental characteristics of the sea area where the sand curtain is applied to provide input conditions for the design of the sand curtain parameters. It includes the design water depth, current velocity, and wave conditions. Taking the approach channel of a coastal port in Bohai Sea in China as an example, under the extreme high tide level of this sea area, the water depth of the channel beach is 12 m, the maximum average flow velocity is 0.8 m / s, the design effective wave height is 3.5 m, and the average wave period is 9 s. Then, the underwater sand curtain based on the flexible mooring form is constructed. Figure 1 The structure diagram of the underwater sand curtain suitable for offshore construction according to the present application is shown in Figure 1 The underwater sand curtain suitable for offshore construction includes a flexible curtain module and an anchoring assembly, the anchoring assembly is connected to the seabed beach, and the bottom of the flexible curtain module is connected to the anchoring assembly.

[0046] The flexible curtain module includes a plurality of flexible curtains A1, a float belt A2 is connected to the top of the plurality of flexible curtains A1, the flexible curtains A1 are all reinforced synthetic fiber geotextiles, a plurality of longitudinally parallel longitudinally main cables A5 and a plurality of transversely parallel transversely secondary cables A4 are arranged on the flexible curtains A1, the transversely secondary cables A4 and the longitudinally main cables A5 form a grid structure for dispersing stress, the longitudinally main cables A5 are used to bear the main tension of the flexible curtains A1, and the transversely secondary cables A4 are used to bear the secondary tension of the flexible curtains A1; the anchoring assembly includes a seabed pile foundation A6, a Hall anchor A8, and a connecting anchor cable A3, the seabed pile foundation A6 and the Hall anchor A8 are both connected to the seabed beach, one end of the connecting anchor cable A3 is connected to the top of the seabed anchor pile, and the other end of the connecting anchor cable A3 is connected to the float belt A2. The bottom of the flexible curtain A1 is provided with a counterweight iron chain A7, the counterweight iron chain A7 is tied to the bottom of the flexible curtain A1, and the counterweight iron chain A7 is connected to the Hall anchor A8. The float belt A2 includes a plurality of float units, and the float units are connected to each other by flexible cables. As a preferred embodiment of the present application, the height of the flexible curtain A1 in the water depth direction is higher than the water depth corresponding to the highest sea water tide level.

[0047] The present application also provides a laying method of the underwater sand curtain suitable for offshore construction, which includes the following steps:

[0048] Step 1: Analyze the environmental characteristics of the sea area where the pile-anchor integrated underwater sand curtain is applied to provide input conditions for the parameter design of the pile-anchor integrated underwater sand curtain, including the water depth of the channel beach, the current velocity and the wave conditions.

[0049] Step 2: Based on the water depth of the channel beach, the current velocity and the wave conditions, determine the design parameters of the pile-anchor integrated underwater sand curtain, which is to be laid in the channel beach. The maximum water depth in this area is 12m, and the height of the flexible curtain A1 is greater than the maximum water depth, such as the height of the flexible curtain A1 being 15m. It is preliminarily estimated that the buoy belt A2 has a buoyancy of 1.5 tons per meter; the subsea pile foundation A6 has a spacing of 200m and can provide a shear and uplift resistance of 50 tons. Specifically, Figure 5 For the partial sand curtain test data-flow velocity and water retention ratio relationship diagram (the buoyancy of the buoy belt A2 is 1.5 tons per meter), as shown in Figure 5 Under the condition that the buoyancy of the buoy belt A2 is 1.5 tons per meter, the underwater water retention ratio of the sand curtain can exceed 50% under the normal sea area flow velocity condition. The vertical coordinate in the figure represents the ratio of the water passing height of the sand curtain buoy upper part to the water depth, and it can be seen that under the condition that the flow velocity does not exceed 1m / s, the water retention ratio (1-h / d) exceeds 50%. Wherein: V represents the flow velocity (m / s); L represents the curtain length (m); h represents the water passing height (m); d represents the water depth (m); F represents the single-width floating force of the top floating body structure (N / m); f represents the single-width anchor pulling force (N / m); V 2 ρd / F represents the dimensionless velocity; f / F represents the dimensionless pulling force; L / d represents the dimensionless curtain length; h / d represents the dimensionless water passing height.

[0050] The weight of the counterweight iron chain A7 is 50 kilograms per meter; a Hall anchor A8 is arranged at a spacing of 5 meters at the flexible connecting bottom cable, and the weight of a single Hall anchor A8 is 3.5 tons; the bearing capacity of the primary and secondary cables of the flexible curtain A1 is 50 tons per meter.

[0051] Step 3: Physical model test is carried out on the design parameters of the pile-anchor integrated underwater sand curtain, specifically including scaling the integrated underwater sand curtain according to a model scale of 1:25, arranging the scaled sand curtain model in a wave and current test harbor pool, and applying wave and current velocities in the wave and current test harbor pool to form wave and current loads on the flexible curtain body module, measuring the underwater water-retaining height of the flexible curtain body module by using a steel ruler, determining the design parameter combination of the pile-anchor integrated underwater sand curtain, after the above-mentioned measurement of the underwater water-retaining height of the flexible curtain body module by using a steel ruler, taking 20 kilograms of dry weight of model sand with a median particle size of 0.1 mm, uniformly throwing it into the test water body at a position 5 meters upstream of the pile-anchor integrated underwater sand curtain within 2 minutes, closing the water flow and wave making system 2 minutes after the throwing is completed, weighing the dried sand at the bottom of the upstream section of the sand curtain module, calculating the sand retention ratio, and verifying the sand retention effect of the pile-anchor integrated underwater sand curtain according to the sand retention ratio.

[0052] Step 4: Constructing the pile-anchor integrated underwater sand curtain according to the design parameter combination of the pile-anchor integrated underwater sand curtain, the pile-anchor integrated underwater sand curtain comprising a flexible curtain body module and an anchoring assembly, wherein the flexible curtain body module comprises a plurality of flexible curtain bodies A1, and the anchoring assembly comprises a seabed pile foundation A6, a Hall anchor A8 and a connecting anchor cable A3.

[0053] The flexible curtain body module functions to hinder water and sand transport, and appropriate synthetic fiber geotextile, longitudinal main cable A5 and transverse secondary cable A4 need to be selected in combination with the corresponding environmental load to ensure sufficient tensile strength of the flexible curtain body A1. Specifically, the flexible curtain body A1 is a reinforced synthetic fiber geotextile, and the longitudinal main cable A5 and the transverse secondary cable A4 of the flexible curtain body A1 are made of ultra-high molecular weight polyethylene material. The breaking force of this kind of cable is extremely strong, for example, the breaking force of a 24mm diameter ultra-high molecular weight polyethylene material cable is 50.4 tons. In the design process, the influence of the harsh marine environment is considered, so reinforced synthetic fiber geotextile is used as the main material of the curtain body, and at the same time, this kind of flexible curtain body A1 has a certain self-adaptability in water. When the external wave and current load is large, the curtain body will be depressed, the flow area will be reduced, and thus the load will be reduced.

[0054] The main function of the float belt A2 is to provide sufficient buoyancy to lift the flexible curtain module and maintain the good underwater posture of the flexible curtain A1. The anchoring assembly composed of the underwater pile foundation A6, the Hall anchor A8 and the counterweight chain A7 mainly functions to constrain the displacement of the flexible curtain A1 and resist the external load on the flexible curtain A1. Therefore, the length of the curtain, the spacing and shear resistance of the underwater pile foundation A6, the spacing and weight of the Hall anchor A8, and the weight of the counterweight chain A7 need to meet the sufficient bearing capacity. The above-mentioned related design parameters can be determined according to the environmental characteristics of the application sea area and by carrying out a sand curtain model test. The above-mentioned related design parameters are mutually restricted, and a parameter combination scheme needs to be developed, and the effect of the scheme needs to be evaluated. The evaluation criteria for the pros and cons of the scheme are that the load of the sand curtain anchoring system is small (the pulling force at each mooring point is not more than 30 tons), the underwater water retaining height is high (the ratio of the water retaining height to the water depth is greater than 50%), and in the case of meeting the above-mentioned targets, the maximum sand retaining capacity of the sand curtain is taken as the standard to select the best scheme to achieve good sand retaining effect. Specifically, in the process of carrying out a sand curtain physical model test, the main parameters can be cross-combined to form a test matrix. For example, a number of flow velocities (0.2 m / s, 0.4 m / s, 0.6 m / s, 0.8 m / s, 1.0 m / s), a number of test water depths (design high water level, average water level, and design low water level in the engineering sea area), a number of curtain heights (1.5 times, 1.0 times, 0.8 times, and 0.4 times the water depth value relative to the design high water level), and a number of float belt A2 buoyancy per meter (0.5 tons / m, 1 ton / m, 1.5 tons / m, and 2 tons / m) are selected. Under the cross-combination of the above-mentioned parameters, a test working condition matrix table covering typical parameter combinations is formed, and through the test, more comprehensive test results can be obtained.

[0055] The sediment conditions are different in different sea areas, such as different sediment discharge, different sediment particle size (which affects the movement of sediment), different flow dynamic conditions, and different flow direction characteristics (recurrent flow and rotating flow). Therefore, the evaluation criteria for judging the parameters of the sand curtain cannot be quantified, and a relative comparison method is adopted. Under the conditions of meeting the survival ability of the sand curtain, i.e. the load of the sand curtain anchoring system is small (the pulling force at each mooring point is not more than 30 tons), and the sufficient water retaining height, i.e. the ratio of the underwater water retaining height to the water depth is greater than 50%, the sand curtain can have better effect. Through the test, the sand retaining effect in the corresponding sea area is simulated, and a relative comparison is made to select the parameter combination with the largest sand retaining capacity of the sand curtain as the best scheme.

[0056] In the implementation process, by adjusting the size of the float belt A2, the float belt A2 can change the buoyancy of the sand curtain, and the water retaining height of the sand curtain will be increased under the same wave load, and the sand retaining effect will also be improved. However, when the float belt A2 buoyancy exceeds 1.5 tons per meter, it will lead to an increase in the load of the anchoring assembly, and the weight of the Hall anchor A8 needs to be increased, and the carrying capacity of the corresponding main and secondary cables and the connecting anchor cable A3 needs to be increased. The longer the length of the curtain body, the higher the underwater water retaining height. The weight and specification of the connecting anchor cable A3 affect the tension of the float belt A2, and increasing the weight of the connecting anchor cable A3 can better resist the wave load of the float belt A2, but it also has a pulling effect on the float belt A2, which reduces the water retaining height of the sand curtain.

[0057] Step 5: The seabed pile foundation A6 is arranged at intervals of 200m in the sea area, and the float belt A2 is connected to the seabed pile foundation A6 by the connecting anchor cable A3;

[0058] Step 6: The total length of the pile-anchor integrated underwater sand curtain is 20km, which is segmented and synchronized, with a single segment being 1km long. Five construction ships are arranged for deployment. The single segment flexible curtain body module is loaded on the construction ship, and after reaching the predetermined position, the construction ship slowly sails along the planned route. During this period, the flexible curtain A1-weighted iron chain A7-float belt A2-Hall anchor A8 combination is gradually thrown and placed, and the connecting anchor cable A3 is connected to the flexible curtain A1 at the position of the seabed pile foundation A6. Finally, the pile-anchor integrated underwater sand curtain is deployed. Specifically, Figure 2 is a load transmission diagram of the integrated underwater sand curtain, Figure 3 is a force analysis diagram of the float belt A2, Figure 4 is a force analysis diagram of the flexible curtain A1, as Figure 2 , Figure 3 and Figure 4 shown, wherein α is the angle between the top tangent of the flexible curtain A1 and the vertical direction, and θ is the angle between the bottom tangent of the flexible curtain A1 and the horizontal direction. It can be seen that by adjusting the parameters of each component of the flexible sand curtain, the purpose of controlling the underwater posture of the flexible curtain A1 and the force direction of the anchoring system can be achieved. The optimal parameter combination can be determined through model test research to meet the design goal of low cost and high efficiency. Then, a rapid deployment plan for the sand curtain construction at sea is developed. The sea area channel is about 20km long, and the sand curtain is arranged on the south side of the channel to block the sand invasion on the south side of the channel, with a total length of 20km.

[0059] As a preferred embodiment, first, for the sea area where the sand curtain is to be arranged, the environmental condition information of the maximum water depth, the engineering design wave height, the engineering design wave period, etc. of the sea area is collected to provide input conditions for the design, arrangement and construction of the sand curtain. Then, according to the sand curtain structure mentioned in the patent, the sand curtain is constructed, including the flexible curtain body module, the float belt A2 and the anchoring assembly. Then the design parameters of the corresponding components are selected, and the size of the float belt A2, the design bearing capacity of the primary and secondary cables of the flexible curtain body A1, the shear resistance and uplift resistance of the seabed anchor pile of the anchoring system, the weight of the Hall anchor A8, the length of the curtain body, etc. are selected in the process. The goal is to reduce the load of the anchoring system, improve the water retaining height and thus improve the sand retaining effect. The parameters interact with each other, and the sand curtain system is scaled according to a model scale of 1:25. The sand curtain model is arranged in the wave and current test harbor basin. Tension sensors are arranged at the connection between the bottom of the sand curtain and the anchoring system for monitoring the stress of the anchoring system. Wave and current velocities are applied in the wave and current test harbor basin to form wave and current loads on the sand curtain. The underwater water retaining height of the sand curtain is measured by using a steel ruler, and the amount of sand retained is observed to verify the effect of the sand curtain system. Then, according to the main direction of the sediment in the engineering sea area, one or more planning lines are arranged along the orthogonal direction of the sand curtain, which can be straight lines or curved lines. Considering the convenience of construction, the sand curtain is divided into several units for arrangement, and the weight of each unit of the sand curtain is matched with the capacity of the construction ship. Then the construction ship is arranged. Before the construction ship is used to lay the sand curtain, a seabed pile foundation A6 is arranged at an interval of about 200m in the predetermined sea area. The float belt A2 is connected to the top of the pile by using the connecting anchor cable A3, and the other end of the anchor chain is connected to the positioning buoy. In order to facilitate construction and arrangement, the total length of the sand curtain is 20km, which is segmented and arranged synchronously. The single segment is 1km long, and 5 construction ships are arranged for laying. The single segment of the sand curtain system is loaded on the construction ship, which slowly sails along the planning line after reaching the predetermined position. During this period, the combination of the flexible curtain body A1, the weight chain A7, the float belt A2 and the Hall anchor A8 is gradually thrown and laid, and the connecting anchor cable A3 is connected to the top cable of the flexible curtain body A1 at the position of the seabed pile foundation A6. Finally, the sand curtain is laid. Specifically, before the sand curtain is laid, the seabed pile foundation A is laid in advance. At each position of the seabed pile foundation A6, the connecting anchor cable A3 is arranged. In order to facilitate construction, one end of the connecting anchor cable A3 is connected to the seabed pile foundation A6, and the other end is hung with a positioning and tracking buoy, which floats on the water surface to provide an indication for the positioning of the construction ship.When the construction ship carrying the combination of flexible curtain A1, weight chain A7, buoy belt A2 and hall anchor A8 sails to the vicinity of a tracer buoy, the buoy belt A2 is first hooked and connected with the top of the anchor cable A3, and then the other parts of the combination of flexible curtain A1, weight chain A7, buoy belt A2 and hall anchor A8, including the weight chain A7 and the hall anchor A8, are thrown at the pile position, and under the action of gravity, the bottom of the combination is bedded on the seabed, and under the action of the buoyancy of the buoy belt A2, the top of the combination of flexible curtain A1, weight chain A7, buoy belt A2 and hall anchor A8 floats up, and finally the sand curtain is opened underwater.

[0060] Embodiment 2: Figure 6 The structure diagram of the sand curtain in this embodiment is shown in Figure 7 The load transmission diagram of the flexible curtain B in this embodiment is shown in Figure 6 And Figure 7 On the basis of embodiment 1, the present application also proposes a sand curtain deformation structure of “underwater sand curtain in flexible mooring form”, which can achieve the effect of reducing siltation and protecting the approach channel at a lower cost. The specific implementation process is as follows: first, analyze the environmental characteristics of the sea area where the sand curtain is applied to provide input conditions for the parameter design of the sand curtain. Including the design water depth, current speed, and wave conditions. Then, construct the underwater sand curtain based on the flexible mooring form. Design the overall underwater sand curtain structure composed of flexible mooring components (including buoy belt B9, buoy belt C16, and flexible curtain B13), dynamic anchoring components (including weight chain B11 and hall anchor B12). As shown in Figure 6 An underwater sand curtain, including a flexible mooring component and a dynamic anchoring component, the dynamic anchoring component is connected to the bottom of the flexible mooring component, and the dynamic anchoring component is used to constrain the displacement of the flexible mooring component; the flexible mooring component includes a buoy belt B9, a buoy belt C16, and a flexible curtain B13, a plurality of buoy belts B9 are connected to the flexible curtain B13, the buoy belt C16 is arranged above the side of the buoy belt B9, the buoy belt B9 and the buoy belt C16 are suspended by a plurality of connecting anchor cables B15, and the buoy belt C16 is suspended on the seabed pile foundation B10 fixed on the seabed beach through a plurality of connecting anchor cables B15; the dynamic anchoring component includes a weight chain B11 and a hall anchor B12, the weight chain B11 is tied to the bottom of the flexible curtain B13, and the weight chain B11 and the hall anchor B12 are linked to each other.

[0061] The flexible curtain B13 blocks the water and sand migration. The main function of the float belt B9 and the float belt C16 is to provide sufficient buoyancy to lift the flexible curtain B13 and keep it in a good flexible underwater posture. The float belt C16 is arranged on the water surface, and the flexible curtain B13 is constrained by the float belt C16, the mooring chain 14 and the submarine pile foundation B10. The main function of the dynamic anchoring assembly composed of the counterweight chain B11 and the Hall anchor B12 is to constrain the displacement of the flexible curtain B13 and resist part of the external load on the flexible curtain B13. Therefore, the submarine pile foundation B10 spacing, the shear resistance, the mooring chain 14 specification, the Hall anchor B12 spacing and weight, and the counterweight chain B11 weight need to meet the sufficient bearing capacity.

[0062] The application further provides a laying method of the underwater sand curtain, comprising the following steps:

[0063] Step 1: analyzing the environmental characteristics of the sea area where the sand curtain is applied to provide input conditions for the parameter design of the sand curtain, wherein the environmental characteristics of the sea area where the sand curtain is applied include the water depth of the channel side beach, the current velocity and the wave condition;

[0064] Step 2: determining the design parameters of the sand curtain based on the water depth of the channel side beach, the current velocity and the wave condition;

[0065] Step 3: The design parameters of the sand curtain need to be compared and selected through physical model tests. Through physical model tests, the design parameter combination of the sand curtain is determined. The design parameters of the sand curtain are determined through model tests according to the environmental characteristics of the application sea area. Further, in terms of the derivation of environmental parameters and sand curtain design parameters, the environmental parameters of the proposed project sea area are simulated using physical model test methods, including flow velocity and direction, wave conditions, water depth conditions, and sediment characteristics. By selecting different sand curtain design parameters, including the size of the float belt B9, the size of the float belt C16, the weight and specification of the mooring chain 14, the shear resistance and uplift resistance of the submarine pile foundation B10, the design bearing capacity of the primary and secondary cables of the flexible curtain body B13, the weight of the Hall anchor B12, and the length of the flexible curtain body B13, several typical parameters are selected for each design parameter. For example, the size of the float belt B9, the size of the float belt C16 (0.5 tons per meter, 1.0 tons, 1.5 tons), the weight and specification of the mooring chain 14 (diameter 18mm, 24mm, 30mm), the weight of the Hall anchor B12 (1 ton, 2 tons, 3 tons), and the length of the flexible curtain body B (relative to the design water depth ratio, curtain body length 0.5 times water depth, 1 times water depth, 1.5 times water depth). By cross-combining the above typical parameters, a test working condition matrix covering typical parameter combinations can be obtained. The corresponding anchor cable stress and sand trapping capacity measured by physical model tests can be used as a basis for evaluating the advantages and disadvantages of sand curtain parameters. Specifically, the size of the float belt C16, the weight and specification of the mooring chain 14, the shear resistance and uplift resistance of the submarine pile foundation B10, the weight of the Hall anchor B12, and the length of the flexible curtain body B13 are given during the design process. By adjusting the relevant parameters, a higher water retaining height can be achieved under smaller dynamic anchoring component loads, thereby achieving good sand trapping effect. The above-mentioned related design parameters are mutually constrained, and parameter combination schemes need to be developed and the effects of the schemes need to be evaluated. The evaluation criteria for the advantages and disadvantages of the schemes are small dynamic anchoring component loads (each mooring point tension not exceeding 30 tons) and the underwater water retaining height of the flexible curtain body B13 (water retaining height to water depth ratio greater than 50%). Under the condition of meeting the above targets, the maximum sand trapping capacity of the flexible curtain body B13 is used as the standard to select the optimal scheme to achieve good sand trapping effect. In the specific implementation process, by adjusting the size of the float belt B9 and the float belt C16, the buoyancy of the float belt B9 and the float belt C16 on the sand curtain body can be changed. According to the stress analysis, under the same wave and current load, the water retaining height of the sand curtain body will be increased, and the sand trapping effect will also be improved. If the buoyancy of the float belt B9 and the float belt C16 is large, it will also lead to an increase in the dynamic anchoring component load, which requires increasing the weight of the Hall anchor B12 and enhancing the bearing capacity of the anchor chain, while also increasing the shear resistance and uplift resistance of the submarine pile foundation B10. The longer the length of the flexible curtain body B13, the higher the underwater water retaining height.The weight and specification of the mooring chain 14 affect the tension of the pontoon belt B9, pontoon belt C16, increasing the weight of the mooring chain 14 can better resist the wave flow load of the pontoon belt B9, pontoon belt C16, but also has a pulling effect on the pontoon belt B9, pontoon belt C16, reducing the water retaining height of the yarn curtain.

[0066] The design parameters of the sand curtain need to be compared and selected by physical model test, including: scaling the sand curtain, arranging the scaled sand curtain model in the wave and current test harbor, arranging tension sensors at the connection between the bottom of the sand curtain model and the dynamic anchoring assembly for monitoring the stress of the dynamic anchoring assembly. Wave and current velocities are applied in the wave and current test harbor to form wave and current loads on the sand curtain, and the underwater water retaining height of the sand curtain is measured by a steel ruler, and the sand retaining amount is observed, thereby verifying the effect of the sand curtain. Specifically, according to the engineering sea area environmental conditions and the sand curtain design parameters, the physical model test parameters are designed; the prototype test water depth is 12 m, the average flow velocity is 0.8 m / s, the design effective wave height is 3.5 m, and the wave average period is 9 s as the input parameters of the physical model test. Through the physical model test input parameters, the required model test scale is determined according to the test site, instrument performance and test purpose; considering that the test is carried out in a two-dimensional wave and current tank, combined with the performance of the wave maker, the current making ability of the tank, the maximum test water depth of the tank and other factors, the model scale of this test is set to 1:25, and the model is a normal model. According to the model scale, combined with the design parameter combination of the sand curtain, the sand curtain model is processed and scaled, and is arranged in the test tank, and the model needs to meet the gravitational similarity criterion. At the connection between the bottom of the flexible curtain B13 model and the dynamic anchoring assembly, a DYLY-108 type tension sensor with a range of 50 N and an accuracy of 0.1% is arranged for monitoring the stress of the dynamic anchoring assembly. According to the gravitational similarity criterion, wave and current velocities are applied in the wave and current test harbor to form wave and current loads on the scaled sand curtain model, and the underwater water retaining height of the sand curtain is measured by a steel ruler. Then, 20 kilograms of model sand with a median particle size of 0.1 mm is weighed, and is uniformly thrown into the test water body at a position 5 meters upstream of the sand curtain model within 2 minutes. After 2 minutes of throwing, the water flow and wave making system is turned off, the sand at the bottom of the upstream section of the sand curtain is weighed after drying, the sand retaining ratio of the sand curtain is calculated, which is used as a scheme evaluation index, and the scheme with the highest sand retaining ratio is selected as the optimal scheme.

[0067] Step 4: Construct the sand curtain according to the design parameters of the sand curtain to be laid on the sea area, the sand curtain comprising a flexible mooring assembly and a dynamic anchoring assembly, wherein the flexible mooring assembly comprises a buoy belt B9, a buoy belt C16, and a flexible curtain body B13, and the dynamic anchoring assembly comprises a counterweight chain B11 and a Hall anchor B12; specifically, the underwater sand curtain is to be laid on the channel beach, the maximum water depth of the area is 12m, the selected sand curtain body 5 height is greater than the maximum water depth, and the flexible curtain body B13 is 15m high. It is preliminarily estimated that the buoy belt C16 has a buoyancy of 0.8 tons per meter; the underwater pile foundation B10 has a spacing of 200m and can provide a shear and uplift resistance of 20 tons; the mooring chain 14 has a diameter of 50mm; the counterweight chain B has a weight of 50kg per meter; a Hall anchor B12 is arranged at the bottom of the flexible curtain body B13 with a spacing of 5m, and the weight of a single Hall anchor B12 is 2 tons.

[0068] Step 5: Lay the underwater pile foundation B10 at intervals of 400m in the sea area, and lay the buoy belt C16 in the flexible mooring assembly on the sea surface, and connect the buoy belt C16 and the underwater pile foundation B10 by the mooring chain 14;

[0069] Step 6: According to the main direction of the sediment in the engineering sea area, one or more planning lines are laid along the orthogonal direction to lay the sand curtain. The planning line can be a straight line or an arc line. Considering the construction convenience, the sand curtain is divided into multiple units, and the multiple sand curtain units are laid by the construction ship. The sand curtain is loaded on the construction ship, the construction ship slowly sails along the planning line after reaching the predetermined position, and the combination of the flexible curtain body B13, the buoy belt B9, the buoy belt C16, the counterweight chain B11 and the Hall anchor B12 is gradually thrown and placed during the period. The buoy belt B9 in the flexible mooring assembly and the buoy belt C16 laid on the sea surface are connected by the connecting anchor cable B15, and finally the laying of the sand curtain is completed.

[0070] As a preferred embodiment, a rapid deployment scheme for sand curtain offshore construction is developed: the length of the sea area channel is 20 km, and to block the sand invasion on the south side of the channel, a sand curtain is arranged on the south side of the channel, with a total length of 20 km. For the sea area where the sand curtain is to be arranged, the design wave height and design wave period of the engineering sea area are calculated using a wave and current mathematical model, and the maximum ebb and flow velocity at the position where the sand curtain is to be arranged is calculated, providing input conditions for the design, arrangement and construction of the sand curtain. Then, the underwater sand curtain is constructed, including flexible mooring components and dynamic anchoring components. Then, the design parameters of the corresponding components are selected, including the size of the float belt B9 and the float belt C16, the weight and specification of the mooring chain 14, the shear resistance and uplift resistance of the submarine pile B10, the design bearing capacity of the primary and secondary cables of the flexible curtain body B13, the weight of the Hall anchor B12, and the selection of the length parameters of the curtain body. During the parameter selection process, the goal is to reduce the load of the anchoring system, improve the water retaining height and thus improve the sand retaining effect. The parameters interact with each other, and physical model tests are carried out for verification. According to the water transportation engineering simulation test regulations, the sand curtain is scaled according to a model scale of 1:25, and wave and current loads are applied in the wave and current test harbor pool. The load of the dynamic anchoring component and the water retaining height of the flexible curtain body B13 are measured, and the sand retaining effect is observed, thereby verifying the effect of the sand curtain. Then, the sand curtain model is arranged in the wave and current test harbor pool, and a tension sensor is arranged at the connection between the bottom of the sand curtain model and the anchoring system, for monitoring the stress of the anchoring system, Figure 5 The test data of the partial sand curtain are shown in the flow velocity and water retaining ratio relationship diagram as shown in Figure 5 The wave and current flow velocity are applied in the wave and current test harbor pool to form wave and current loads on the sand curtain. The underwater water retaining height of the sand curtain is measured using a steel ruler, and the sand retaining amount is observed, thereby further verifying the effect of the sand curtain.

[0071] Then, according to the main direction of the sediment in the engineering sea area, one or more planning lines are laid along the orthogonal direction of the main direction, which can be straight lines or curved lines. Considering the construction convenience, the sand curtain is divided into several units for laying, and the weight of each unit sand curtain is matched with the capacity of the construction ship. Then, the construction ship is laid. Before the construction ship lays the sand curtain, a seabed pile foundation B10 is laid at an interval of 400 m in the predetermined sea area, and a floating tube belt C16 is laid on the sea surface, and the floating tube belt C16 and the seabed pile foundation B10 are connected by using a mooring anchor chain 14. In order to facilitate construction and laying, the total length of the sand curtain is 20 km, which is segmented and laid synchronously, and the length of each segment is 1 km. Five construction ships are arranged to lay the sand curtain. The single-segment sand curtain is loaded on the construction ship, and after reaching the predetermined position, the construction ship slowly sails along the planning line. During this period, the combination of the flexible curtain B13, the floating tube belt B9, the floating tube belt C16, the weight iron chain B11 and the Hall anchor B12 is gradually thrown. The floating tube belt B9 in the flexible mooring assembly is connected with the floating tube belt C16 laid on the sea surface by the connecting anchor cable B15, and finally the laying of the sand curtain is completed.

[0072] When it is necessary to recover the sand curtain or change its laying direction, the construction ship can be used to sail along the laying planning line, and the flexible curtain B13 is dragged by using the construction ship hoisting equipment, and then the Hall anchor B12 is lifted, and the flexible curtain B13 is gradually collected.

[0073] Embodiment 3: Figure 8 The structure diagram of the sand curtain in this embodiment is shown in the figure, Figure 9 The enlarged structure diagram of the longitudinal main cable B in this embodiment is shown in the figure, Figure 10 The enlarged structure diagram of the Hall anchor C in this embodiment is shown in the figure, Figure 8 , Figure 9 and Figure 10As shown, the present application is also designed on the basis of example 1, a pile anchor separation type underwater sand curtain suitable for offshore construction, including: flexible curtain body C17, flexible curtain body C17 is used for sand blocking, flexible curtain body C17 includes at least one longitudinal main cable B18 and transverse secondary cable B19, which is composed of reinforced synthetic fiber geotextile, the manufacturing process includes weaving high-strength longitudinal cable into synthetic fiber geotextile as longitudinal main cable B18 to bear the main tension, weaving cable with relatively low strength into geotextile as transverse secondary cable B19 to form grid structure to disperse stress, high-strength longitudinal cable is used as top cable and bottom cable at the top and bottom, longitudinal main cable B18 and transverse secondary cable B19 are staggered, which can better block the sediment and expand the blocking density, flexible curtain body C17 further includes connecting piece 181 provided on longitudinal main cable B18, connecting piece 181 is used for connecting with float belt D20, connecting piece 181 is connected with float belt D20 through flexible cable to transfer buoyancy, the bottom of flexible curtain body C17 is provided with counterweight iron chain C22, which is used for pulling down flexible curtain body C17, counterweight iron chain C22 is tied at the bottom of flexible curtain body C17, the weight of counterweight iron chain C22 is fifty kilograms per meter, which ensures that the bottom cable of flexible curtain body keeps dynamic contact with seabed through the action of falling, avoids the curtain body from separating from the seabed to produce sand penetration under the action of water flow, and maintains the relaxed posture of the curtain body under water, the bottom end of longitudinal main cable B18 is connected with Hall anchor C23, and Hall anchor C23 assists in fixing the axial position of the curtain body through the grip force.

[0074] Float belt D20 is provided on flexible curtain body C17, and the specific position is the top of flexible curtain body C17, which is used for pulling up flexible curtain body C17, float belt D20 is at least one, and all float belts D20 are connected with each other by cable, part of float belts D20 is connected with one end of connecting anchor cable C21, float belt D20 provides upward floating force for the flexible curtain body, and the size of the floating force directly affects the underwater posture of the curtain body and the stress of the bottom anchoring system, which needs to be designed according to the model test results, the ratio of water blocking height to water depth can be greater than 50%, the upward floating force of float belt D20 and the downward pulling force of counterweight iron chain C22 form a synergistic effect, so that the flexible curtain body presents a certain floating posture under the action of current and wave force, cuts off the near-bottom sediment transport path, the other end of connecting anchor cable C21 is connected with seabed pile foundation C24, and seabed pile foundation C24 and connecting anchor cable C21 are used for pulling float belt D20, which is used to reduce the influence of ocean current on float belt D20, so that flexible curtain body C17 and float belt D20 form a C shape, and the sand blocking effect is expanded.

[0075] The Hall anchor C23 is arranged on the flexible curtain C17, and is arranged at the bottom of the flexible curtain C17. The Hall anchor C23 is used for limiting the flexible curtain C17. The Hall anchor C23 comprises an assembly 234 connected with the longitudinal main cable B18. The assembly 234 is used for connecting a plurality of anchor body units into one. The assembly 234 is connected with a connecting chain 233. The connecting chain 233 is used for connecting the anchor body unit and the assembly 234 into one. One end of the connecting chain 233 is provided with the anchor body unit. The anchor body unit is used for fixing the flexible curtain C17. The anchor body unit comprises a bearing 232 connected with the connecting chain 233. The bearing 232 is provided with a connecting shaft 235. The connecting shaft 235 is provided with an anchor tip 231. The connecting end of the bearing 232 and the connecting chain 233 is provided with a connecting hole. The connecting hole is used for connecting with the connecting chain 233. The anchor tip 231 rotates on the bearing 232 through the connecting shaft 235. When the Hall anchor C23 is arranged, the Hall anchor C23 is arranged along the sand curtain axis at an interval of 5 m. The plane arrangement can be at an appropriate angle with the axis of the seabed pile C24. After being thrown, the anchor tip 231 rotates on the bearing 232 through the connecting shaft 235 and enters the river bottom mud, so as to provide the gripping force for the flexible curtain C17 to assist the flexible curtain C17 to share the wave load.

[0076] The seabed pile C24 is connected with the pontoon belt D20. The seabed pile C24 is used for limiting the pontoon belt D20. When the seabed pile C24 is arranged, the seabed pile C24 needs to be arranged at an interval of 200 m along the sand curtain arrangement line. The top of the seabed pile C24 is connected with the pontoon belt D20 through the connecting anchor cable C21. The connecting anchor cable C21 is in a catenary line posture under water. The seabed pile C24 can provide a shear resistance of 50 tons and an uplift resistance. The wave load is transmitted through the pontoon belt D20, the connecting anchor cable C21 and the seabed pile C24. The catenary line posture converts most of the horizontal load into the pile shear resistance, so as to reduce the stress of the anchoring system single point.

[0077] In terms of environmental adaptability, the height of the flexible curtain C17 along the water depth direction needs to be slightly higher than the water depth corresponding to the highest seawater tide level. If the sea area is 12 m deep, the height of the selected flexible curtain C17 should be 15 m, so as to ensure that the flexible curtain C17 is stretched in the tidal change. The buoyancy parameter of the pontoon belt D20 needs to be adjusted in combination with the sea current flow rate and wave conditions. If the flow rate is 0.8 m / s, the buoyancy of 1.5 tons per meter can meet the water retaining height requirement. If the flow rate increases to 1.2 m / s, the buoyancy needs to be increased to 2.0 tons. However, the weight of the Hall anchor C23 needs to be increased to at least 4.5 tons, and the shear resistance of the seabed pile C24 needs to be increased to 60 tons. The weight of the counterweight chain C22 is related to the seabed bottom. The chain weight needs to be increased to 60 kg / m to ensure that the bottom cable is attached to the ground.

[0078] In use of the pile-anchor separated underwater sand-retaining screen suitable for offshore construction, first, the seabed pile foundation C24 is set at intervals of 200 meters along the edge of the engineering area, such as the beach between the channels, and the seabed pile foundation C24 is connected with the pontoon belt D20 through the catenary-shaped connecting anchor cable C21; the flexible screen body C17 is made of reinforced synthetic fiber geotextile, the longitudinal main cable B18 and the transverse secondary cable B19 of which form a grid structure in staggered manner, the top of which is connected with the pontoon belt D20 through the connecting piece 181, and the bottom of which is connected with the Hall anchor C23 by binding every meter of 50 kilograms of counterweight iron chain C22 at intervals of five meters. The upward floating force provided by the pontoon belt D20 and the downward pulling force of the counterweight iron chain C22 form a balance, so that the flexible screen body C17 assumes an inclined posture under the action of the sea current and the wave, cuts off the sediment-laden water body transport path near the bottom, and changes the water flow field to promote sediment settlement; the wave and flow load is transmitted to the seabed pile foundation C24 through the connecting anchor cable C21 of the pontoon belt D20, and the catenary-shaped connecting anchor cable C21 converts most of the horizontal load into the shear resistance of the seabed pile foundation C24, while the Hall anchor C23 is thrown and the anchor tip 231 is rotated into the soil on the bearing 232 through the connecting shaft 235 to provide grip force to assist in restraining the position of the screen body. The pile-anchor separated underwater sand-retaining screen in the application is optimized and designed according to the sea environment parameters through model test, so as to ensure that the ratio of the water retaining height to the water depth is more than 50%, and high-efficiency sand cutting and siltation promotion are realized; when recovered, the longitudinal main cable B18 of the flexible screen body C17 is pulled by the construction ship, and the Hall anchor C23 is lifted to complete the recovery of the sand-retaining screen.

[0079] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An underwater sand-blocking curtain suitable for offshore construction, characterized in that, It includes a flexible mooring assembly and a dynamic anchoring assembly. The dynamic anchoring assembly is connected to the bottom of the flexible mooring assembly and is used to restrain the displacement of the flexible mooring assembly. The flexible mooring assembly includes float belts B (9), float belts C (16), and flexible curtains B (13). Multiple float belts B (9) are connected to the flexible curtains B (13). Float belts C (16) are located above the sides of float belts B (9). Float belts B (9) and float belts C (16) are connected to each other by multiple connecting anchor cables B (15). Float belts C (16) are connected to seabed piles B (10) fixed to the seabed surface by multiple connecting anchor cables B (15). The dynamic anchoring assembly includes a counterweight chain B (11) and a Hall anchor B (12). The counterweight chain B (11) is tied to the bottom of the flexible curtain B (13), and the counterweight chain B (11) and the Hall anchor B (12) are linked together.

2. The underwater sand-blocking curtain suitable for offshore construction according to claim 1, characterized in that, The pontoon belt B (9) includes multiple pontoon units, which are interconnected by flexible cables.

3. A method for deploying underwater sand-blocking curtains suitable for offshore construction, characterized in that: Includes the following steps: Step 1: Analyze the environmental characteristics of the marine area where the sand barrier curtain is applied to provide input conditions for the design of the sand barrier curtain parameters. The environmental characteristics of the marine area where the sand barrier curtain is applied include the water depth of the channel beach, the current velocity and wave conditions. Step 2: Determine the design parameters of the sand-blocking curtain based on the water depth, current velocity, and wave conditions along the channel. Step 3: Conduct physical model tests to compare and select the design parameters of the sand-blocking curtain. Through physical model tests, determine the combination of design parameters for the sand-blocking curtain. The design parameters of the sand-blocking curtain are determined by conducting sand-blocking curtain model tests based on the characteristics of the marine environment in which it is to be deployed. The environmental parameters of the marine area to be deployed are simulated using physical model tests. The environmental parameters include water flow velocity and direction, wave conditions, water depth conditions and sediment characteristics. Different sand-blocking curtain design parameters are selected according to the environmental parameters. The design parameters of the sand-blocking curtain include the size of the buoy belt B (9) and buoy belt C (16), the weight and specifications of the mooring anchor chain (14), the shear and pull-out resistance of the seabed pile foundation B (10), the design bearing capacity of the main and secondary cables of the flexible curtain B (13), the weight of the Hall anchor B (12) and the length parameters of the flexible curtain B (13). Through the cross combination of the above sand-blocking curtain design parameters, a test condition matrix covering typical parameter combinations is obtained. Step 4: Construct the sand barrier to be deployed in the sea area according to the design parameters of the sand barrier. The sand barrier includes a flexible mooring component and a dynamic anchoring component. The flexible mooring component includes float belt B (9), float belt C (16), and flexible curtain B (13). The dynamic anchoring component includes counterweight iron chain B (11) and Hall anchor B (12). Step 5: Install underwater sand-blocking curtains on the channel side beach. The maximum water depth of the channel side beach is 12m. The height of the selected sand-blocking curtain (5) is greater than the maximum water depth of the channel side beach. The height of the flexible curtain (13) is 15m. Install seabed piles (10) at intervals of 400m in the sea area. Set the spacing between each seabed pile (10) to be 200m. Arrange a Hall anchor (12) at a spacing of 5m at the bottom of the flexible curtain (13). Install the buoy belt (16) in the flexible mooring assembly on the sea surface. Connect the buoy belt (16) to the seabed pile (10) using the mooring anchor chain (14). Step 6: Based on the main direction of the sediment in the engineering sea area, lay out one or more planned lines along its orthogonal direction to lay out the sand-blocking curtains, and divide the sand-blocking curtains into multiple units. The construction vessel lays out multiple sand-blocking curtain units. The sand-blocking curtains are loaded on the construction vessel. After the construction vessel reaches the predetermined position, it slowly sails along the planned route. During this period, the combination of flexible curtain body B (13) - float belt B (9) - float belt C (16) - counterweight iron chain B (11) - Hall anchor B (12) is gradually released. The float belt B (9) in the flexible mooring component is connected to the float belt C (16) laid on the sea surface through the connecting anchor cable B (15) to finally complete the laying of the sand-blocking curtain.

4. The method for deploying underwater sand-blocking curtains suitable for offshore construction according to claim 3, characterized in that, In step 3, the physical model test to compare and select the design parameters of the sand-blocking curtain includes: scaling up the sand-blocking curtain, placing the scaled-up sand-blocking curtain model in the wave and current test basin, placing a tension sensor at the connection between the bottom of the sand-blocking curtain model and the dynamic anchoring component to monitor the stress on the dynamic anchoring component; applying wave and water flow velocity in the wave and current test basin to form wave and current load on the sand-blocking curtain, measuring the underwater water-blocking height of the sand-blocking curtain with a steel ruler, observing the amount of sand blocked, and verifying the effect of the sand-blocking curtain.

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