CN117890076B - Sinking power response fine simulation test device and method for open caisson - Google Patents

Abstract

The invention discloses a sinking power response fine simulation test device and a test method thereof for a sunk well, wherein the device is used for improving the reliability and the precision of the sinking power response simulation test result of the sunk well and exploring the sinking power response mechanism and rule of the sunk well, and the device comprises: the power environment simulation system is used for simulating the single action simulation and the combined action simulation of wind, wave and current on the open caisson; the open caisson model is used for simulating an embedded steel open caisson; the anchoring cable system model is used for installing the open caisson model in the dynamic environment simulation system; the test auxiliary support mechanism is used for assisting the test device to install the detection equipment; the physical parameter measurement system is used for monitoring and collecting data and test conditions of the test device; the method is applied to the sinking dynamic response fine simulation test device of the sinking well.

Description

A fine simulation test device for the dynamic response of sinking water in caisson and its test method

Technical Field

The invention relates to the technical field of physical models of dynamic response of moored floating bodies, in particular to a fine simulation test device for dynamic response of sinking wells and a test method thereof.

Background Art

Caisson foundation has the advantages of strong integrity, good stability and relative economy. It is a widely used type of pier foundation in cross-river and cross-sea bridges. It has unique advantages in deep and fast-flowing inland waters and offshore waters with harsher dynamic environments. Embedded caisson is a caisson foundation construction method that prefabricates the caisson, excavates the foundation pit, and then builds it through floating, sinking and bottom sealing construction processes. It has been applied in many actual projects.

The underwater sinking construction is one of the key construction links of the embedded caisson. This link mainly solves the problems of safe and stable sinking and precise landing control of the caisson. In this link, the caisson is a large floating structure. It not only faces the hydrodynamic problems involved in traditional large floating structures, but also faces some other scientific and technological problems closely related to its morphological characteristics. Clarifying the dynamic response characteristics and laws of the embedded caisson sinking in a complex dynamic environment is of great significance for scientifically guiding and optimizing the design of the caisson positioning system, and ensuring and improving the caisson landing positioning accuracy.

The caisson sinking construction process is subject to the effects of various dynamic factors such as wind, current, waves, and tides. In addition to the influence of the irregular geometric bottom boundary, the environmental dynamics will also show more significant three-dimensional characteristics in the depth direction, and the construction dynamic environment is complex. In addition, the mooring cable system used for caisson sinking positioning is a hyperstatic flexible constraint system composed of multiple cables. There is a complex interaction between the mooring cable system and the caisson. During the sinking process of the caisson, the buoyancy and stability parameters such as the deadweight, buoyancy center position, center of gravity position, and moment of inertia will change with the depth of entry into the water. Therefore, the caisson sinking system composed of the caisson-mooring cable system itself has more complex dynamic characteristics. The dynamic response of the caisson underwater sinking construction is a complex response of a complex structural system under the action of a complex dynamic environment, including the movement of the caisson and the force of the anchor cable. It involves disciplines such as fluid dynamics, rigid body dynamics, and cable dynamics. Accurately characterizing the properties of the caisson and the cable system, the dynamic environment, the fluid-solid interaction, and the caisson-cable interaction is the key to simulating this complex response. In view of the complexity of the problem process and the physical mechanisms involved, the physical model test method is currently a research method that is widely recognized and relied upon in the industry for studying the characteristics and laws of the dynamic response of caisson sinking.

Theoretically, the physical model test of the dynamic response of the embedded steel caisson sinking belongs to the mooring test of floating structure. The model design and test can be carried out according to the conventional mooring test procedures such as ship mooring. However, due to the particularity of the embedded steel caisson itself, when carrying out the physical model test of the dynamic response of the embedded steel caisson sinking, it is necessary to solve many problems that may not be faced in a series of conventional mooring tests. It is mainly reflected in: (1) The embedded steel caisson is a complex geometric structure with multiple wells, thin walls and hollows. In the sinking process, the key parameters affecting the dynamic response of the caisson, such as the deadweight and center of gravity, buoyancy and center of buoyancy, and moment of inertia, will gradually change with the sinking depth. The caisson model and prototype based on the existing technology are difficult to simultaneously meet the similarity of appearance scale and the similarity of mass distribution during the entire sinking process. Therefore, it is impossible to strictly meet the geometric similarity, dynamic similarity and motion similarity, and the experimental simulation of the dynamic response of the caisson sinking is difficult to implement. In engineering, the prototype wall thickness of a general steel caisson is 10 to 30 mm. According to the physical model test, the wall model thickness obtained by scaling with a geometric scale (1:50) is only 0.2 to 0.5 mm. The existing technology can use 0.2 to 0.6 mm thin iron sheets to make iron boxes with relatively simple regular shapes (such as cylinders, prisms or square boxes), but it is difficult to make complex caisson models with many holes inside. Even if it is barely feasible, the time and economic costs are very high, that is, the nested steel caisson model based on the idea of "completely proportional scaling and processing and manufacturing with the same material" is difficult to implement. At present, the conventional caisson models based on the idea of "scaling the appearance proportionally and processing and manufacturing with different materials" and their advantages and disadvantages are as follows: (a) Models with similar appearance scales but different mass distributions: plastic plates with relatively high density and high hardness are used as the basic material, and are formed after cutting, gluing, waterproofing, spray painting and other processes. The overall strength and stiffness of the caisson model made by this method are good, and it can better meet the geometric similarity and similarity of environmental loads such as wind, waves and currents, but it is difficult to achieve the similarity of its own weight and mass distribution. Therefore, it is mostly used for physical model tests to measure the environmental loads acting on the caisson, but it cannot be used for physical model tests that need to consider the motion response of the caisson itself. (b) Models with similar appearance and mass distribution: low-density hard foam board is used as the basic material for model making, and it is formed after cutting, gluing, waterproofing, painting and other processes, and a small volume of counterweight lead blocks are placed in appropriate positions to achieve the similarity of weight and mass distribution. The caisson model made by this method can better meet the geometric similarity and similarity of environmental loads such as wind, waves and currents, as well as the similarity of dynamic response under the action of environmental loads. It can be used for physical model tests to measure environmental loads on the caisson, and can also be used for physical model tests involving the motion response of the caisson itself. Although it is easy to achieve similar mass distribution under fixed deadweight conditions by using lead block counterweights, it is difficult to apply to situations where the deadweight changes with different water depths during the sinking construction process. In summary, the existing caisson model is difficult to apply to the simulation study of the dynamic response of caisson sinking. (2) The mooring cable system used for caisson positioning contains a large number of cables. The cable length and initial tension need to be adjusted before the test. During the cable adjustment process, the mutual interference between the cables is large and the adjustment process is complicated. A convenient cable fixing device and initial tension application method also need to be effectively solved.

Developing a practical caisson sinking dynamic response simulation test device and test method to achieve accurate inversion of the caisson's own motion and the positioning system cable force under different sinking depths is of great engineering and scientific value in guiding the caisson sinking construction.

Summary of the invention

The present invention can produce a caisson model that meets similar criteria with the prototype in terms of geometry, dynamics and motion, conveniently realizes complete similarity of the total weight and moment of inertia of the caisson under different water entry depths during the sinking process, accurately and efficiently applies a preset level of initial tension in a complex positioning cable system, effectively solves the problems of low similarity of caisson models and difficulty in applying a preset initial tension of the cable, effectively improves the reliability and accuracy of the simulation test results of the caisson sinking dynamic response, and constructs an effective way to explore the mechanism and law of the caisson sinking dynamic response to further guide the caisson sinking construction.

To achieve the above purpose, one of the technical solutions of the present invention is: a fine simulation test device for the dynamic response of caisson sinking, which is used to improve the reliability and accuracy of the simulation test results of the dynamic response of caisson sinking, and explore the mechanism and law of the dynamic response of caisson sinking. The device includes:

Dynamic environment simulation system, used to simulate the individual and combined effects of wind, waves and current on the caisson;

Caisson model, used to simulate embedded steel caisson;

The mooring cable model is used to install the caisson model in the dynamic environment simulation system;

A test auxiliary bracket mechanism, used to assist the test device in installing the testing equipment;

Physical parameter measurement system is used to monitor and collect data and test conditions of the test device.

Furthermore, the power environment simulation system includes:

The test pool has a main structure of side walls and a pool bottom, and a rectangular plane shape; the test pool is divided into a non-test area and a test area; the pool bottom terrain of the test area is scaled according to the actual terrain; the non-test area is used for the generation, transition or elimination of waves and flow forces; the non-test area is provided with an inlet, an outlet, a wave-making plate, and a wave-breaking facility; the inlet is located at one side wall of two opposite sides of the test pool; the outlet is located at the other side wall of the test pool; the outlet is connected to the inlet by a return pipe and/or a corridor; the return pipe and the corridor are both provided with a water pump; the water pump is driven by a motor;

The flow-making facility is used to construct the flow field, and is composed of a flow-making water pump group, a return corridor or pipeline, an energy dissipation and rectification device, and a flow control module; the energy dissipation and rectification device is located at the inlet, and is used to achieve a rapid and smooth transition of the water flow;

The wave-making facilities include a wave-making machine and a wave-breaking device, which are used to simulate a wave field; the wave-making machine is composed of a wave-making panel, a servo drive motor, and a wave-making module; the wave-making panel is arranged on one side wall, the wave-breaking device is located on the side wall corresponding to the wave-making panel, and the wave-making panel and the wave-breaking device are arranged above the inlet and the outlet; the wave-making module controls the servo drive motor to drive the wave-making panel to simulate various types of waves in the pool;

The wind-generating facilities are composed of multiple independent fans and frequency converters, which are used to simulate wind fields. The fans can be freely moved and arranged in any combination. They are installed at preset plane positions and vertical heights in the test area of the test pool through brackets to control the height and direction of the wind field. The wind speed is regulated by adjusting the fan speed through the frequency converter.

Furthermore, the caisson model includes:

Main wall panels, model wall panels, model wall surfaces, horizontal ribs between caisson model wall panels, vertical ribs between caisson model wall panels, and connecting holes;

The main wall panels, the model wall panels, the model wall surface, the horizontal ribs between the caisson model wall panels, and the vertical ribs between the caisson model wall panels are fixedly connected to each other;

The top and sides of the caisson model are equipped with cable-mooring platforms; the outer wall of the caisson model is equipped with plumb lines and horizontal loops;

Among them, by filling the hollow wall compartment formed between the wall panels of the caisson model with high-concentration salt water, the caisson can be counterweighted at different sinking depths to solve the problem of different weight and mass distribution at similar water filling heights caused by the fact that the wall thickness of the model and the prototype do not strictly meet the geometric similarity.

The concentration of the injected brine is calculated by the ratio of the total wall thickness inside and outside the caisson model to the wall plate thickness.

Furthermore, the mooring line model includes: a series of model cables and line locks;

The series of model cables include a single-segment spring and/or a multi-segment series-parallel spring group for simulating cable deformation, and a fiber rope.

Further, the test auxiliary support mechanism includes:

The instrument and equipment bracket is used to place instruments and equipment for measuring and collecting physical parameters such as caisson movement and cable tension; wherein the bracket is a frame structure, including supporting columns and a frame platform;

Positioning bracket, used to fix the caisson model, so as to efficiently and accurately apply the preset initial tension to the series of cables of the positioning cable system;

The caisson model is fixed to the positioning bracket, and the positioning bracket is fixed to the supporting column of the instrument and equipment bracket to achieve the fixation of the caisson model;

The connecting trestle is a trestle leading to the test auxiliary support and is used for pedestrians, observation and wiring functions.

Furthermore, the physical parameter measurement system includes a tension sensor for measuring cable tension, a motion measurement device for measuring the six-degree-of-freedom motion of the caisson rigid body, a camera for observing the caisson movement and water surface status, as well as a water level meter for measuring water level, a wave height meter for measuring wave height, a flow meter for measuring flow velocity, and an anemometer for measuring wind speed.

One of the technical solutions of the present invention is: a fine simulation test method for the dynamic response of sinking caisson, which is applied to the above-mentioned fine simulation test device for the dynamic response of sinking caisson.

Further, the method comprises:

S1. Based on the similarity criteria that should be followed in the mooring physical model test, comprehensively consider the test requirements, dynamic conditions, site conditions and other factors, determine the geometric scale of the model test. To ensure the test accuracy, the geometric scale should not be less than 1:80; calculate the model scale of relevant physical parameters such as force, displacement, velocity, etc.;

S2. Make the test site according to the designed test scale, strictly control the elevation error of the test site terrain, and the test area should meet the basic test requirements; set up wind, current and wave making equipment, and the power conditions provided should meet the basic test requirements; set up instrument and equipment brackets and connecting trestles; install wire lockers at the anchor point;

S3. According to the design test scale, a caisson model is made by combining 3D printing technology with traditional technology, and a salt water counterweight that meets the density requirements is configured. According to the specifications of the prototype cable, the model cable parameters are calculated, and a positioning cable model is made. The model cable meets the requirements of the test similarity criteria;

S4. Lay out instruments and equipment for measuring wind, waves, currents, and water levels, inspect and calibrate the instruments and equipment to ensure that they work properly; carry out calibration of environmental dynamic conditions to ensure that the simulation accuracy of environmental dynamics meets the test requirements;

S5. Install a wire locker on the mooring point of the caisson model, then move it to the test point and connect the model cable connected in series with a dynamometer and a spring; add salt water into the wall compartment so that the caisson model reaches a predetermined depth in the water, and determine whether it is in a positive floating state through the vertical scale lines and horizontal loops on the outer surface of the caisson model, otherwise make adjustments;

S6. Lay out instruments and equipment for measuring caisson movement, and start instruments and equipment for measuring cable tension and caisson movement;

S7, by using a positioning bracket to fix the caisson model, applying a preset level of initial tension to all model cables; after the initial tension is applied, the fixing bracket is removed;

S8. Start the test by operating the computer to turn on the environmental simulation system. The test duration and number of groups meet the test requirements. Save the test data for further analysis.

S9. After completing the test of one working condition, repeat S1-S8 to change the test dynamic conditions or the water depth of the caisson model to carry out tests under other working conditions.

Beneficial effects:

1. The overall structure of the caisson model is similar to the prototype, which is a thin-walled hollow watertight plastic wall panel structure; the appearance dimensions of the model and the prototype fully meet the geometric similarity, and the thickness of the model wall is controlled by mass similarity and mass distribution similarity. The caisson model itself fully meets the test similarity criteria and is suitable for dynamic response tests that need to consider the movement of the caisson itself. The caisson model can be made by combining advanced 3D printing technology with traditional model making technology. The model is solid and firm, and the molding scheme is economical and feasible.

2. There are wall compartments for water filling and counterweighting between the wall panels of the caisson model that are similar in volume. By filling with salt water with higher density to replace the conventional water with lower density, the total weight and height of water filling can be similar under different water entry depths during the caisson sinking process, thereby ensuring the similarity of the caisson mass distribution and moment of inertia at the corresponding water entry depth. It not only retains the same counterweight implementation method as in actual engineering, but also ensures the complete similarity of the counterweight, laying the foundation for efficient and accurate caisson sinking dynamic response tests.

3. In the test, the caisson model was fixed with a positioning bracket, and then the initial tension was applied to the cables of the mooring cable system of the caisson model, which effectively improved the efficiency and accuracy of applying the initial tension of the cables, and avoided the problem that the preset initial tension may not be achieved after repeated adjustment of the cables. It plays an important role in improving the accuracy of the test simulation.

4. The cable lock locks the cable, which greatly improves the convenience of adjusting the cable length and makes frequent adjustments of many cables flexible.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic side view of the overall test device of the present invention;

FIG2 is a schematic diagram of an overall top view of the test device of the present invention;

FIG3 is a schematic diagram of a caisson mooring cable model and a test auxiliary support;

Fig. 4 is an enlarged view of point A in Fig. 3;

Fig. 5 is an enlarged view of point B in Fig. 3;

Figure 6 is a schematic diagram of the overall structure of the caisson model;

FIG7 is an enlarged view of point C in FIG6;

FIG8 is an enlarged view of point D in FIG6;

FIG9 is an enlarged view of point E in FIG6 ;

FIG10 is an enlarged view of point F in FIG6 ;

Figure 11 is a schematic diagram of the layered and block-shaped forming of the main body of the caisson model;

Figure 12 is a diagram of vertical and horizontal scale lines on the outer wall of the caisson model;

FIG13 is an enlarged view of FIG12;

FIG14 is a schematic diagram of the water injection state of the caisson model at different water immersion depths;

FIG15 is a schematic diagram illustrating the effect of adding ordinary water and high-density brine on mass distribution;

Figure 16 is a time history curve of the caisson translation component obtained from the model test;

FIG17 is a time history graph of the caisson rotation component obtained from the model test;

FIG18 is a time history curve of cable tension of the mooring system obtained from the model test;

Figure 19 is a graph showing the relationship between the amplitude of the caisson translational component and the relative sinking depth and effective wave height obtained from the model test;

Figure 20 is a graph showing the relationship between the amplitude of the caisson rotation component and the relative sinking depth and effective wave height obtained from the model test;

Figure 21 is a graph showing the relationship between the maximum increase in cable tension in the mooring system and the relative sinking depth and effective wave height obtained from the model test.

Among them: 1. Test pool; 11. Test pool side wall; 12. Water surface line; 121. Backwater corridor; 13. Pool bed; 14. Project area topography; 21. Flow pump; 22. Efficiency facilities; 23. Rectifier plate; 24. Pool water inlet; 25. Pool water outlet; 31. Wave maker; 32. Wave breaking frame; 41. Wind-making facilities; 5. Caisson model; 50. Caisson foundation pit; 51. Caisson construction platform; 52. Caisson model main wall panel; 521. Model wall panel; 522. Model wall surface; 53. Horizontal ribs between the wall panels of the caisson model; 54. Vertical ribs between the wall panels of the caisson model; 55. Connecting holes; 6. Mooring cables; 61. Wire lock; 62. Tension gauge; 63. Spring; 64. Mooring platform; 65. Bed anchor point; 71. Instrument and equipment bracket; 711. Frame platform; 712. Support column; 72. Connecting pier; 73. Fixed bracket; 80. Water depth of caisson; 81. Filling of water into the caisson wall compartment; 91. Horizontal scale lines of the caisson model; 92. Vertical scale lines of the caisson model.

DETAILED DESCRIPTION

Embodiment 1:

The present invention is described in detail below in conjunction with the accompanying drawings, which include a fine simulation test device for the dynamic response of sinking water in a caisson and a fully automatic assembly device having the device.

As shown in Figure 1-13, the caisson sinking dynamic response fine simulation test device is used to improve the reliability and accuracy of the caisson sinking dynamic response simulation test results and explore the mechanism and law of the caisson sinking dynamic response. The device includes:

Dynamic environment simulation system, used to simulate the individual and combined effects of wind, waves and current on the caisson;

Specifically, the power environment simulation system includes:

The test pool has a main structure of side walls and a pool bottom, and a rectangular plane shape; the test pool is divided into a non-test area and a test area; the pool bottom terrain of the test area is scaled according to the actual terrain; the dynamic conditions in the test area are balanced and stable, and are used for conducting tests; the non-test area is used for the generation, transition or elimination of waves and flow forces; inlets, outlets, wave-making plates, and wave-breaking facilities are arranged in the non-test area; the inlet is located at one side wall of two opposite sides of the test pool; the outlet is located at the other side wall of the test pool; the outlet and the inlet are connected by a return pipe and/or a corridor; water pumps are provided on the return pipe and the corridor; the water pump is driven by a motor; the flow-making pump is a reversible water pump, and the motor is a variable frequency motor, and the direction and speed of the flow-making can be flexibly controlled by controlling the direction and speed of the variable frequency motor.

The flow-making facility is used to construct the flow field, and is composed of a flow-making water pump group, a return corridor or pipeline, an energy dissipation and rectification device, and a flow control module; the energy dissipation and rectification device is located at the inlet, and is used to achieve a rapid and smooth transition of the water flow;

The wave-making facilities include a wave-making machine and a wave-breaking device, which are used to simulate a wave field; the wave-making machine is composed of a wave-making panel, a servo drive motor, and a wave-making module; the wave-making panel is arranged on one side wall, the wave-breaking device is located on the side wall corresponding to the wave-making panel, and the wave-making panel and the wave-breaking device are arranged above the inlet and the outlet; the wave-making module controls the servo drive motor to drive the wave-making panel to simulate various types of waves in the pool;

The wind-generating facilities are composed of multiple independent fans and frequency converters, which are used to simulate wind fields. The fans can be freely moved and arranged in any combination. They are installed at preset plane positions and vertical heights in the test area of the test pool through brackets to control the height and direction of the wind field. The wind speed is regulated by adjusting the fan speed through the frequency converter.

Also included is the Caisson model, which simulates an embedded steel caisson;

Furthermore, the caisson model includes:

Main wall panels, model wall panels, model wall surfaces, horizontal ribs between caisson model wall panels, vertical ribs between caisson model wall panels, and connecting holes;

The main wall panels, the model wall panels, the model wall surface, the horizontal ribs between the caisson model wall panels, and the vertical ribs between the caisson model wall panels are fixedly connected to each other;

The top and sides of the caisson model are provided with mooring platforms; the outer wall of the caisson model is provided with plumb lines and horizontal loops;

Among them, by filling the hollow wall compartment formed between the wall panels of the caisson model with high-concentration salt water, the caisson can be counterweighted at different sinking depths to solve the problem of different weight and mass distribution at similar water filling heights caused by the fact that the wall thickness of the model and the prototype do not strictly meet the geometric similarity.

The concentration of the injected brine is calculated by the ratio of the total wall thickness inside and outside the caisson model to the wall plate thickness.

Specifically, the main body plane of the caisson model is divided into multiple independent parts, and each part is fixed by gluing or other means. The parts are composed of thin-walled hollow watertight plastic wall panels. The wall panels are hollow structures, consisting of inner wall surfaces, outer wall surfaces, and internal horizontal and vertical ribs. The ribs divide the internal space of the wall panels into many wall compartments. The ribs are provided with connecting holes for connecting the wall compartments. A mooring platform is provided on the top or side of the caisson model. A plumb line and a horizontal loop are provided on the outer wall surface of the caisson model. In addition to the main body, the caisson model also has models of auxiliary structures such as construction platforms and leveling columns. The thin-walled hollow structure of the wall panels can ensure that the surface density is similar while satisfying the similarity of the displacement volume to ensure the similarity of the buoyancy, thereby ensuring the similarity of the weight, mass distribution and moment of inertia. The ribs provided in the thin-walled hollow wall panels can ensure that the wall panels have sufficient strength and rigidity. The wall compartment in the wall panel can be used for water injection, so as to flexibly realize the similar simulation of the change of the deadweight of the caisson with different water depths during the sinking process of the caisson. The water injection of the wall compartment is realized through the connecting hole, the water pump and the water injection pipe. The mooring platform is used to fix the wire lock for mooring. The plumb line and the horizontal loop can be used to intuitively evaluate the floating state of the caisson after entering the water. It should be noted that the appearance scale of the caisson model and the prototype meets the geometric similarity, but the wall thickness is not required to strictly meet the geometric similarity.

The caisson model has a very thin wall (2-4 mm), so it is not feasible to form it entirely by traditional manual molding. Instead, it can be formed by injection molding or by combining 3D printing technology with traditional technology. In view of the fact that injection molding requires injection molds, has high production costs, long production cycles, and is not suitable for the production of single-piece small-batch plastic parts, it is recommended to use 3D printing technology combined with traditional technology for molding. The specific production process is as follows: (a) Using computer-aided design software, the appearance dimensions of the caisson prototype are scaled according to the designed geometric scale (the relationship between the appearance dimensions of the model and the appearance dimensions of the prototype is shown in formula (1)), and the three-dimensional geometric modeling of the appearance of the caisson model is implemented. (b) According to the total weight and mass distribution of the caisson, the surface density of the wall at each position of the caisson model is calculated (the calculation formula is shown in formula (2)), and combined with the density of the substrate used for model production, the wall thickness at each position of the model and the hollow thickness between the wall panels are determined (the calculation formulas are shown in formulas (3), (4), and (5)). (c) Considering that the wall thickness of the caisson model constructed according to the similar appearance geometry and mass distribution is relatively thin, the strength and stiffness of the hollow wall in a large area will be low, which is not conducive to ensuring the overall strength and stiffness of the model. The stiffness and strength of the thin-walled hollow plastic wallboard are enhanced by properly arranging horizontal and vertical ribs. The thickness of the ribs can be designed to be consistent with the wall thickness. After adding the ribs, the wall thickness is recalculated taking into account the mass of the ribs. (d) The overall size of the caisson model may be large. The geometric model can be divided into a series of smaller parts suitable for 3D printing through horizontal block division and vertical layer division. The horizontal block division position is between the vertical ribs, and the layer division position is set immediately below the horizontal ribs. In this way, the support structure required for 3D printing can be fully exposed, which is convenient for the later removal of the support structure. At the same time, each layer is a bottom-sealed open structure, which is convenient for the later watertight test. In addition, in order to facilitate the subsequent bonding of components, the wall thickness is thickened inward in the local range of the block-to-block joint and the layer-to-layer joint. (e) Export the 3D printing three-dimensional data file format of the caisson model components, use ABS or PLA materials to 3D print the layered and divided caisson model components through the FDM process, and use small wire diameter and small layer height printing (wire diameter and layer height are not greater than 0.2mm) to improve the density of the wall surface. (f) Remove the component support structure and perform layer smoothing on the outer surface of the component. On the one hand, it is beneficial to improve the surface smoothness of the component and improve the appearance. On the other hand, it is also beneficial to eliminate the hidden danger of water leakage caused by printing gaps to enhance its waterproof effect. (g) Use glue to stick the layers of the plane components, waterproof the bonding parts, perform watertightness test on the bonded plane components, and waterproof or reprint the parts that do not meet the requirements to ensure that all plane components have good waterproof effect. (h) Glue the plane components that pass the watertightness test to form a whole, apply atomic putty on the surface of the caisson model, and spray paint to further improve its overall waterproof performance and surface finish. (i) Use 3D printing technology or conventional methods to make the construction platform and leveling columns and other auxiliary structures on the caisson, and install them on the caisson model that has passed the watertight test. (j) Construct multiple plumb lines at equal intervals on the outer surface of the caisson by pasting a cloth ruler or manually, and construct multiple horizontal lines at appropriate heights. At this point, the caisson model is completed.

In order to solve the problem of different weight and mass distribution at similar water injection heights caused by the wall thickness of the model and the prototype not strictly meeting the geometric similarity, the counterweight at different sinking depths of the caisson is achieved by filling the hollow wall compartment between the wall panels of the caisson model with high-concentration salt water with a relatively high density, rather than filling it with conventional water. The concentration of the injected salt water is related to the ratio of the total thickness of the inner and outer walls of the caisson model to the thickness of the wall panels. Since the manufactured caisson model and the prototype meet the geometric similarity in the wall panel thickness, but the wall thickness does not completely meet the geometric similarity, the volume of the model and the prototype that can be injected at the corresponding water immersion depth cannot meet the volume similarity. Since the total thickness of the inner and outer walls in the caisson model is greater than the thickness scaled strictly according to the geometric scale, the volume of the caisson model that can be injected will be smaller than the volume scaled according to the scale. If the similarity of the injected weight is to be ensured, the water density needs to be increased. The present invention uses salt water of different salinities as the injected water body, and the density of the injected salt water can be calculated according to formulas (6) and (7), and the corresponding water body salinity can be preliminarily determined by formula (8).

d _m,void =d _m,board -2d _m,w3D (4)

d _m,board = λd _p,board (5)

In the above equations, L, W, H, and D represent the length, width, height, and wall thickness of the caisson, respectively (all in m), and the subscripts m and p are used to distinguish the model value from the prototype value, respectively; λ is the geometric scale (dimensionless); m _p,Area is the total mass of the wall of a certain area at a certain position of the caisson prototype (unit: kg); _Ap is the wall area at the corresponding position of the caisson prototype (unit: m ² ); ρ _m,Area is the wall density of the model (unit: kg/m ² ); ρ _p,Area is the wall density of the prototype (unit: kg/m ² ); d _m,w3D is the wall thickness of the model (unit: m); ρ _3D is the density of the material used for 3D printing the model (unit: kg/m ³ ); d _m,void is the hollow thickness of the model wall after removing the wall thickness (unit: m); d _m,board is the thickness of the model wall (unit: m); d _p,board is the thickness of the prototype wall (unit: m); ρ _m,S is the density of the brine used for filling the model (unit: kg/m ³ ); d _p,wCaisson is the thickness of the caisson prototype wall; d _m,wCaisson is the wall thickness corresponding to the model wall made of the same material as the caisson prototype wall (usually steel) (unit: m); ρ _p,Caisson is the density of the material used to make the caisson prototype wall (unit: kg/m ³ ); _ρ is the density of fresh water (unit: kg/m ³ ); ρ _m,S is the density of the brine used for counterweights (unit: kg/m ³ ); S is the salinity of the brine used for counterweights (unit: ‰).

It also includes a mooring cable model for installing the caisson model in the dynamic environment simulation system;

Furthermore, the mooring line model includes: a series of model cables and line locks;

The series of model cables include a single-segment spring and/or a multi-segment series-parallel spring group for simulating cable deformation, and a fiber rope.

Specifically, the mooring cable model consists of a series of model cables and wire locks. The model cable consists of two parts. The first part is a single-segment spring or a multi-segment series-parallel spring group used to simulate the deformation of the cable, and the second part is a steel wire rope or a lightweight and high-strength fiber rope. The model cable must meet the following three similarity conditions: (a) Geometric similarity: that is, the relative position and distance between the mooring point on the caisson and the anchor point on the base bed or the anchor pile are similar, and the cable length and cable thickness are similar. (b) Elastic similarity: The force-deformation curves of the original and model cables meet similarity conditions. If the linear relationship of the cable force-deformation curve in the working section is good, a single-segment spring can be used. If the nonlinear relationship is more obvious, a spring group can be used. (c) Weight similarity: The weight of the cable per unit length of the original and model cables meets the gravity similarity condition, that is, the linear density is similar. The weight similarity of the original and model cables is achieved by using a steel wire rope or a high-strength fiber rope of the same material with a diameter scaled according to the geometric ratio. If the linear density cannot meet the requirements, it is necessary to hang or connect tiny particles in series for counterweight.

The cable is fixed by a wire locker based on the principle of friction self-locking. The bottom end of the model cable is connected to the anchor point through the wire locker, and the top end is connected to the mooring point of the caisson model through the wire locker. A certain length of cable is reserved at both the bottom and the top. The spring and the dynamometer are connected in series near the top of the model cable to reduce the probability and influence of water disturbance on the spring and the dynamometer, and to facilitate the measurement of the maximum tension on the cable line length. By fixing the wire locker based on the principle of friction self-locking and capable of firmly locking the steel wire rope to the mooring point on the caisson and the anchor point on the bed, the cable can be quickly connected to the mooring point and the anchor point, and the length and tension of the cable can be flexibly and accurately controlled. The efficiency and accuracy of cable adjustment during the test can be greatly improved.

It also includes a test auxiliary bracket mechanism for assisting the test device in installing the detection equipment;

Further, the test auxiliary support mechanism includes:

The instrument and equipment bracket is used to place instruments and equipment for measuring and collecting physical parameters such as caisson movement and cable tension; the bracket is a frame structure, including supporting columns and a frame platform;

Specifically, the bracket is made of aluminum profiles, which can effectively avoid the problem of interference with electromagnetic motion measuring instruments caused by iron brackets while ensuring the strength and rigidity of the bracket; the bracket is arranged around the embedded foundation pit of the caisson and is fixed to the ground through supporting columns. In order to minimize the influence of the supporting columns on the flow field around the caisson, the distance between the supporting columns and the edge of the caisson should not be less than 1 times the horizontal scale of the caisson model, and the supporting columns should be as small as possible while ensuring a stable bracket; the frame platform includes an upper and lower frame platform, and a flat plate for placing instruments and equipment is set up at a corner of the lower frame platform, and the distance between the lower frame platform and the highest test water level is not less than 1 times the height of the caisson model to facilitate smooth entry and exit of the caisson model.

Positioning bracket, used to fix the caisson model, so as to efficiently and accurately apply the preset initial tension to the series of cables of the positioning cable system;

The caisson model is fixed to the positioning bracket, and the positioning bracket is fixed to the supporting column of the instrument and equipment bracket to achieve the fixation of the caisson model;

Specifically, applying initial tension to each cable on a fixed caisson model will not cause changes in the initial tension of other cables due to adjusting the initial tension of one cable, thereby avoiding the problem of repeatedly adjusting the cables but still possibly failing to reach the preset initial tension, and can effectively improve the efficiency and accuracy of applying the initial tension of the cables.

The connecting trestle is a trestle leading to the test auxiliary support and is used for pedestrians, observation and wiring functions.

Specifically, it is a combined structure of beams and columns, the beams are erected on the columns, and the columns are supported on the ground; it is made of iron material.

Physical parameter measurement system is used to monitor and collect data and test conditions of the test device.

Furthermore, the physical parameter measurement system includes a tension sensor for measuring cable tension, a motion measurement device for measuring the six-degree-of-freedom motion of the caisson rigid body, a camera for observing the caisson movement and water surface status, as well as a water level meter for measuring water level, a wave height meter for measuring wave height, a flow meter for measuring flow velocity, and an anemometer for measuring wind speed.

Specifically, the instruments and equipment used to collect cable tension, the instruments and equipment used to collect caisson movement, and the control computer are all placed on the instrument and equipment bracket.

Embodiment 2:

A fine simulation test method for the dynamic response of sinking caisson is applied to the fine simulation test device for the dynamic response of sinking caisson.

Further, the method comprises:

S1. Based on the similarity criteria that should be followed in the mooring physical model test, comprehensively consider the test requirements, dynamic conditions, site conditions and other factors, determine the geometric scale of the model test. To ensure the test accuracy, the geometric scale should not be less than 1:80; calculate the model scale of relevant physical parameters such as force, displacement, velocity, etc.;

S2. Make the test site according to the designed test scale, strictly control the elevation error of the test site terrain, and the test area should meet the basic test requirements; set up wind, current and wave making equipment, and the power conditions provided should meet the basic test requirements; set up instrument and equipment brackets and connecting trestles; install wire lockers at the anchor point;

S3. According to the design test scale, a caisson model is made by combining 3D printing technology with traditional technology, and a salt water counterweight that meets the density requirements is configured. According to the specifications of the prototype cable, the model cable parameters are calculated, and a positioning cable model is made. The model cable meets the requirements of the test similarity criteria;

S4. Lay out instruments and equipment for measuring wind, waves, currents, and water levels, inspect and calibrate the instruments and equipment to ensure that they work properly; carry out calibration of environmental dynamic conditions to ensure that the simulation accuracy of environmental dynamics meets the test requirements;

S5. Install a wire locker on the mooring point of the caisson model, then move it to the test point and connect the model cable connected in series with a dynamometer and a spring; add salt water into the wall compartment so that the caisson model reaches a predetermined depth in the water, and determine whether it is in a positive floating state through the vertical scale lines and horizontal loops on the outer surface of the caisson model, otherwise make adjustments;

S6. Lay out instruments and equipment for measuring caisson movement, and start instruments and equipment for measuring cable tension and caisson movement;

S7, by using a positioning bracket to fix the caisson model, applying a preset level of initial tension to all model cables; after the initial tension is applied, the fixing bracket is removed;

S8. Start the test by operating the computer to turn on the environmental simulation system. The test duration and number of groups meet the test requirements. Save the test data for further analysis.

S9. After completing the test of one working condition, repeat S1-S8 to change the test dynamic conditions or the water depth of the caisson model to carry out tests under other working conditions.

Experimental example:

In order to generate a large flow rate in the test pool, multiple high-power water pumps are arranged at both ends of the test pool. During the test, the water pump at one end fills the test pool with water, and the water pump at the other end pumps water out. Under the joint driving effect of the water pumps on both sides, a large flow rate can be generated in the test pool. In order to ensure the uniformity of the water flow within the width range in the test pool, the return corridors are symmetrically arranged, the water pumps of the same specifications are used, and the efficiency facilities and finishing facilities are set. The wind-making facilities are composed of multiple independent fans of the same specifications. In order to ensure the wind-making effect, the distance between the fan group and the caisson model is appropriately set. The wave-making facilities are composed of a wave maker and a wave-breaking frame. Instruments and equipment such as caisson movement and cable force measurement are placed on the frame platform of the instrument and equipment bracket. The size of the test area is determined according to the set model geometric scale. In this embodiment, the length of the test area is 25 times the diameter of the caisson model, and the width is 15 times the diameter of the caisson model. The terrain model of the surrounding area of the caisson and the caisson foundation pit model are constructed by scaling the geometric scale. The mooring point on the base bed is determined based on its relative position to the caisson pit.

Assume that the relevant parameters of the prototype caisson are: diameter (Φ _p ) 58m, total height (H _p ) 37m, wall thickness (d _p,board ) 2.0m, and the thickness of the inner and outer steel plates constituting the wall (d _p,wCaisson ) are both 25mm. The parameters of the caisson mooring cable system are: composed of 12 steel cables, cable diameter (φ _p ) 100mm, cable length (L _p ) 250m, cable stiffness (k _p ) 2.5×106N/m, and cable initial tension (F _p,initial ) 90t. The wave parameters are: significant wave height (H _s ) 1.5m, average period (T _m ) 5.0s. The relevant parameters of the counterweight are: when the caisson is immersed in the water at a depth of 21m, the height of the water body filled in the caisson is (h _p ) 10m. The geometric scale of the model selected for the test is set to (λ) 1:50. According to equations (1) to (5), the parameters of the caisson model can be determined as follows: model diameter (Φ _m ) 1.16m, model total height (H _m ) 0.74m, model well wall thickness (d _m,board ) 4cm. The caisson model is made of the commonly used 3D printing material ABS, and the density of the model making material ρ _3D is 1.1g/cm ³ , so the model wall thickness d _m,w3D is 3.568mm, and the wall thickness can be approximately 3.6mm. The wall thickness error of the obtained caisson model and the total mass error of the model will not exceed 1%. The hollow thickness d _m,void of the model wall board after removing the wall thickness is 32.8mm. If the wall thickness d _m,wCaisson of the model wall is made of iron material, it is 0.5mm. Taking the density of ordinary water as 1000kg/m ³ , according to formulas (6) to (8), the density of the salt water used for counterweight, ρ _m,S, can be calculated to be 1189.0kg/m ³ , and the salinity, S, is 159.0‰, which is lower than the concentration of saturated salt water at room temperature. The model cable uses a steel wire rope with a diameter (φ _m ) of 2.0mm to meet the similarity of linear density. The length of the model cable (L _m ) is 5.0m, the stiffness of the model cable (k _m ) is 10N/cm, and the initial tension of the model cable is (F _m,initial ) is 7.06N. The wave parameters in the test are an effective wave height of 3.0cm and an average period of 0.707s. When the caisson model is immersed in water at a depth of 0.42m, the height of the water body filled in the caisson is (h _m ) 0.20m.

According to the caisson model parameters and mooring cable model parameters calculated above, the caisson model and mooring cable model can be made. In the process of making the caisson model, the processing and manufacturing principle of "first breaking down the whole into parts, then forming" is followed (as shown in Figure 11), which reduces the printing difficulty of large-size caisson integrated molding. At the same time, the watertight test can be carried out in blocks, which is conducive to the overall meeting of the watertight requirements. The number of vertical ribs and horizontal ribs of the caisson model can be flexibly determined according to the size of the caisson model (as shown in Figure 6). For the caisson model described in this embodiment, 3 layers of horizontal ribs can be arranged, and 4 layers of vertical ribs can be arranged along the radial direction of the caisson. The wall panels between the vertical ribs are divided into many wall compartments, and the horizontal ribs are provided with connecting holes with diameters of 2 cm and 1 cm to realize the connection between the upper and lower wall compartments. For each wall compartment, there are at least two connecting holes, one inlet and one outlet, to meet the requirements of smooth water injection and drainage.

Since the diameter of the caisson model is 1.16m, the spacing of the supporting columns of the instrument and equipment bracket can be designed to be 2.5m, the spacing between the upper and lower platforms of the instrument and equipment bracket frame is 40cm, and the height of the lower platform from the water surface is 80cm. The supporting columns and frame platform are made of aluminum profiles with a cross-section of 4cm long × 4cm wide. The depth of the supporting column buried in the bed surface is 0.5m, and it is firmly connected to the base surface as a whole. One construction method of the fixed bracket is: a long wooden strip and two small wooden blocks are used. The two small wooden blocks are placed on the upper two opposite sides of the center of the caisson plane, and are fixed to the caisson by screws. The long wooden strip is placed on the two small wooden blocks, fixed by screws, and then the wooden strip is fixed to the supporting column of the instrument and equipment bracket (as shown in Figure 3). The connecting trestle is welded and formed by angle steel with a length of 3cm × a width of 3cm × a thickness of 4mm. One end is connected to the instrument and equipment bracket, and the other end leads to the side wall of the test pool.

Four plumb scale lines are evenly arranged in the circumferential direction on the outer wall of the caisson model, and eight horizontal circular lines are arranged in the height direction, which is achieved by pasting a ruler (as shown in Figure 12).

The water filling and weighting of the caisson model can be realized by using a water tank, a variable frequency water pump, a water filling pipe, and a flow regulating valve. When water needs to be added, the variable frequency water pump is turned on, and the salt water that meets the density requirements pre-configured in the water tank is injected into each wall compartment of the caisson model through the water filling pipe and the flow regulating valve. When the caisson is sunk to the predetermined depth, the water filling is finished.

Under different water immersion depths, the amount of water injection and the water injection height required for the counterweight in the caisson are different, as shown in Figure 6. As mentioned above, since the wall thickness is too thin when the caisson model is made of the same material as the prototype (usually steel), it is difficult to produce a caisson model that meets the requirements based on the existing technology, so it is necessary to use heterogeneous materials to appropriately increase the wall thickness to make the caisson model. However, the increase in wall thickness will lead to a decrease in the width of the gap between the wall panels, which will cause the problem of different center of gravity heights of the water body when the same weight of water is injected, and different water weights when the same height of water is injected (as shown in Figure 14). The present invention effectively overcomes the problem of dissimilar water injection quality caused by increased wall thickness by using salt water with adjustable density as the counterweight water body (as shown in Figure 14).

The specific test steps can be implemented according to the test method for fine simulation of the sinking dynamic response of the caisson. The caisson movement and cable tension time history curves of the caisson at a certain sinking depth obtained based on the test device and test method are shown in Figures 16-18, and the change rules of the caisson movement amplitude and cable tension amplitude with relative sinking depth and wave height are shown in Figures 19-21.

The above technical solutions only reflect the preferred technical solutions of the technical solutions of the present invention. Some changes that may be made to certain parts thereof by technicians in this technical field all reflect the principles of the present invention and fall within the protection scope of the present invention.

Claims (7)

1. A fine simulation test device for the dynamic response of sinking caisson, characterized in that the device comprises: Dynamic environment simulation system, used to simulate the individual and combined effects of wind, waves and current on the caisson; Caisson model, used to simulate embedded steel caisson; The mooring cable model is used to install the caisson model in the dynamic environment simulation system; A test auxiliary bracket mechanism, used to assist the test device in installing the testing equipment; Physical parameter measurement system, used to monitor and collect data and test conditions of the test device; Among them, the caisson model includes: Main wall panels, model wall panels, model wall surfaces, horizontal ribs between caisson model wall panels, vertical ribs between caisson model wall panels, and connecting holes; The main wall panels, the model wall panels, the model wall surface, the horizontal ribs between the caisson model wall panels, and the vertical ribs between the caisson model wall panels are fixedly connected to each other; The top and sides of the caisson model are equipped with cable-mooring platforms; the outer wall of the caisson model is equipped with plumb lines and horizontal loops; Among them, by filling the hollow wall compartment formed between the wall panels of the caisson model with high-concentration salt water, the caisson can be counterweighted at different sinking depths to solve the problem of different weight and mass distribution at similar water filling heights caused by the fact that the wall thickness of the model and the prototype do not strictly meet the geometric similarity. The concentration of the added brine is calculated by the ratio of the total wall thickness inside and outside the caisson model to the wall thickness. The calculation process is: d _m,void =d _m,board -2d _m,w3D (4) d _m,board = λd _p,board (5) In the above equations, L, W, H, and D represent the length, width, height, and wall thickness of the caisson, respectively (all in m), and the subscripts m and p are used to distinguish the model value from the prototype value, respectively; λ is the geometric scale (dimensionless); m _p,Area is the total mass of the wall of a certain area at a certain position of the caisson prototype (unit: kg); _Ap is the wall area at the corresponding position of the caisson prototype (unit: m ² ); ρ _m,Area is the wall density of the model (unit: kg/m ² ); ρ _p,Area is the wall density of the prototype (unit: kg/m ² ); d _m,w3D is the wall thickness of the model (unit: m); ρ _3D is the density of the material used for 3D printing the model (unit: kg/m ³ ); d _m,void is the hollow thickness of the model wall after removing the wall thickness (unit: m); d _m,board is the thickness of the model wall (unit: m); d _p,board is the thickness of the prototype wall (unit: m); ρ _m,S is the density of the brine used for filling the model (unit: kg/m ³ ); d _p,wCaisson is the thickness of the caisson prototype wall; d _m,wCaisson is the wall thickness corresponding to the model wall made of the same material as the caisson prototype wall (usually steel) (unit: m); ρ _p,Caisson is the density of the material used to make the caisson prototype wall (unit: kg/m ³ ); _ρ is the density of fresh water (unit: kg/m ³ ); ρ _m,S is the density of the brine used for counterweights (unit: kg/m ³ ); S is the salinity of the brine used for counterweights (unit: ‰). 2. The fine simulation test device for the sinking dynamic response of a caisson according to claim 1 is characterized in that the dynamic environment simulation system comprises: The test pool has a main structure of side walls and a pool bottom, and a rectangular plane shape; the test pool is divided into a non-test area and a test area; the pool bottom terrain of the test area is scaled according to the actual terrain; the non-test area is used for the generation, transition or elimination of waves and flow forces; the non-test area is provided with an inlet, an outlet, a wave-making plate, and a wave-breaking facility; the inlet is located at one side wall of two opposite sides of the test pool; the outlet is located at the other side wall of the test pool; the outlet is connected to the inlet by a return pipe and/or a corridor; the return pipe and the corridor are both provided with a water pump; the water pump is driven by a motor; The flow-making facility is used to construct the flow field, and is composed of a flow-making water pump group, a return corridor or pipeline, an energy dissipation and rectification device, and a flow control module; the energy dissipation and rectification device is located at the inlet, and is used to achieve a rapid and smooth transition of the water flow; The wave-making facilities include a wave-making machine and a wave-breaking device, which are used to simulate a wave field; the wave-making machine is composed of a wave-making panel, a servo drive motor, and a wave-making module; the wave-making panel is arranged on one side wall, the wave-breaking device is located on the side wall corresponding to the wave-making panel, and the wave-making panel and the wave-breaking device are arranged above the inlet and the outlet; the wave-making module controls the servo drive motor to drive the wave-making panel to simulate various types of waves in the pool; The wind-generating facilities are composed of multiple independent fans and frequency converters, which are used to simulate wind fields. The fans can be freely moved and arranged in any combination. They are installed at preset plane positions and vertical heights in the test area of the test pool through brackets to control the height and direction of the wind field. The wind speed is regulated by adjusting the fan speed through the frequency converter. 3. The fine simulation test device for the hydrodynamic response of caisson sinking according to claim 1 is characterized in that the mooring cable model comprises: a series of model cables and a wire lock; The series of model cables include a single-segment spring and/or a multi-segment series-parallel spring group for simulating cable deformation, and a fiber rope. 4. The fine simulation test device for the dynamic response of sinking well according to claim 1 is characterized in that the test auxiliary support mechanism comprises: The instrument and equipment bracket is used to place instruments and equipment for measuring and collecting physical parameters such as caisson movement and cable tension; the bracket is a frame structure, including supporting columns and a frame platform; Positioning bracket, used to fix the caisson model, so as to efficiently and accurately apply the preset initial tension to the series of cables of the positioning cable system; The caisson model is fixed to the positioning bracket, and the positioning bracket is fixed to the supporting column of the instrument and equipment bracket to achieve the fixation of the caisson model; The connecting trestle is a trestle leading to the test auxiliary support and is used for pedestrians, observation and wiring functions. 5. The fine simulation test device for the hydrodynamic response of caisson sinking according to claim 1 is characterized in that the physical parameter measurement system includes a tension sensor for measuring cable tension, a motion measurement device for measuring the six-degree-of-freedom motion of the caisson rigid body, a camera for observing the caisson movement and water surface status, a water level meter for measuring water level, a wave height meter for measuring wave height, a flow meter for measuring flow velocity and an anemometer for measuring wind speed. 6. A method for fine simulation test of the dynamic response of sinking caisson, characterized in that the method is applied to the fine simulation test device for the dynamic response of sinking caisson as described in any one of claims 1-5. 7. The fine simulation test method for the sinking dynamic response of a caisson according to claim 6, characterized in that the method comprises: S1. Based on the similarity criteria that should be followed in the mooring physical model test, comprehensively consider the test requirements, dynamic conditions, site conditions and other factors, determine the geometric scale of the model test. To ensure the test accuracy, the geometric scale should not be less than 1:80; calculate the model scale of relevant physical parameters such as force, displacement, velocity, etc.; S2. Make the test site according to the designed test scale, strictly control the elevation error of the test site terrain, and the test area should meet the basic test requirements; set up wind, current and wave making equipment, and the power conditions provided should meet the basic test requirements; set up instrument and equipment brackets and connecting trestles; install wire lockers at the anchor point; S3. According to the design test scale, a caisson model is made by combining 3D printing technology with traditional technology, and a counterweight salt water that meets the density requirements is configured; according to the specifications of the prototype cable, the model cable parameters are calculated, and a positioning cable model is made. The model cable meets the requirements of the test similarity criteria; S4. Lay out instruments and equipment for measuring wind, waves, currents, and water levels, inspect and calibrate the instruments and equipment to ensure that they work properly; carry out calibration of environmental dynamic conditions to ensure that the simulation accuracy of environmental dynamics meets the test requirements; S5. Install a wire locker on the mooring point of the caisson model, then move it to the test point and connect the model cable connected in series with a dynamometer and a spring; add salt water into the wall compartment so that the caisson model reaches a predetermined depth in the water, and determine whether it is in a positive floating state through the vertical scale lines and horizontal loops on the outer surface of the caisson model, otherwise make adjustments; S6. Lay out instruments and equipment for measuring caisson movement, and start instruments and equipment for measuring cable tension and caisson movement; S7, by using a positioning bracket to fix the caisson model, applying a preset level of initial tension to all model cables; after the initial tension is applied, the fixing bracket is removed; S8. Start the test by operating the computer to turn on the environmental simulation system. The test duration and number of groups meet the test requirements. Save the test data for further analysis. S9. After completing the test of one working condition, repeat S1-S8 to change the test dynamic conditions or the water depth of the caisson model to carry out tests under other working conditions.