A vibration reduction structure and vibration reduction method for a hollow breakwater

Abstract

The present invention discloses a vibration reduction structure and vibration reduction method for a hollow breakwater, the structure includes three grooves in a horizontal row on the top of the breakwater wave plate, the left and right grooves are connected to the middle groove through a horizontal channel, a hydraulic system and a telescopic rod controlled by the hydraulic system and extending vertically upward out of the groove are installed at the bottom of the left and right grooves, a pad for tightening the telescopic rod is arranged on the side walls of the left and right grooves opposite to the above-mentioned channels, a press is installed in the middle groove, the pressure rods on the left and right sides of the press pass through the corresponding channels and are opposite to the telescopic rods in the left and right grooves, and more than two counterweights are placed between the left and right grooves on the top of the wave plate. The vibration reduction structure disclosed by the present invention has a simple structure and is convenient and quick to construct. Based on the principle of a dynamic vibration absorber, it can significantly improve the stability of the hollow breakwater structure and protect it from vibration damage. Although the cost is low, the vibration reduction effect is significant.

Description

Technical Field

[0001] The invention belongs to the field of hollow breakwaters, and in particular relates to a vibration reduction structure and a vibration reduction method of a hollow breakwater in the field. Background Art

[0002] Breakwaters are an important part of port hydraulic structures. They can protect the port waters from the influence of wind and waves, form sheltered waters, and maintain the stability of the port waters. In recent years, with the acceleration of the construction of "Blue Bay" in my country, permeable breakwaters have become a hot topic of research. Permeable breakwaters are generally composed of upper wave-breaking boards and lower supporting piles. They have a simple structure and low construction cost. According to wave theory, waves mainly occur in the range of 2 to 3 times the wave height in the upper layer of the water body, and the concentrated wave energy is about 90% to 98% of the total energy. Therefore, the arrangement of wave-breaking boards near the water surface of permeable breakwaters can play a better role in reducing waves. In addition, its bottom is generally composed of supporting piles inserted into the seabed, which can meet the needs of ensuring seawater exchange and improving the water quality environment in the port. Permeable breakwaters have gradually been implemented in some projects at home and abroad.

[0003] Compared with traditional breakwaters, the bottom of the hollow breakwater is hollow, so the stability and safety of the hollow breakwater are greatly challenged under extreme sea conditions. Under extreme sea conditions, the horizontal displacement of the hollow breakwater is too large, which can easily cause the internal forces on the wave boards and supporting piles to exceed the design requirements. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a vibration reduction structure and a vibration reduction method of a hollow breakwater based on the principle of a dynamic vibration absorber.

[0005] The present invention adopts the following technical solution:

[0006] A vibration reduction structure of a hollow breakwater, the improvement of which is as follows: three grooves in a horizontal row are opened on the top of the breakwater wave plate, the left and right grooves are connected to the middle groove through a horizontal channel, a hydraulic system and a telescopic rod controlled by the hydraulic system and extending vertically upward out of the groove are installed at the bottom of the left and right grooves, a pad for tightening the telescopic rod is arranged on the side walls of the left and right grooves opposite to the above-mentioned channels, a press is installed in the middle groove, the pressure rods on the left and right sides of the press respectively pass through the corresponding channels and are opposite to the telescopic rods in the left and right grooves, and two plates with The two sides of each counterweight plate are respectively inserted into the telescopic rods of the left and right grooves, the upper parts of the two telescopic rods are wound with electromagnetic coils, and the tops are installed with pulleys that can pull the counterweight plates up and down, a wave height meter and a water level meter are installed on the wave-facing side of the wave breakers, and a control system is installed on the top of the wave breakers. The control system is electrically connected to the wave height meter and the water level meter and receives the data sent by them, and is electrically connected to the hydraulic system, the press and the pulley and controls their operation. The battery supplies power to the various components in the vibration reduction structure, and the power switch between the battery and the electromagnetic coil is controlled by the control system.

[0007] Furthermore, the middle groove is located in the middle between the left and right grooves.

[0008] Furthermore, a cushion block is installed at the end of the compression rod opposite to the telescopic rod.

[0009] Furthermore, the length of the electromagnetic coil is greater than the sum of the heights of the weight plates.

[0010] Furthermore, the control system consists of a signal processor and a controller, wherein the signal processor is electrically connected to the wave height meter and the water level meter and receives the data sent by them; the controller is electrically connected to the hydraulic system, the press and the pulley and controls their operation, and the power switch between the battery and the electromagnetic coil is controlled by the controller.

[0011] Furthermore, the magnitude of the current between the battery and the electromagnetic coil is controlled by a controller.

[0012] A vibration reduction method for a hollow breakwater, using the above-mentioned vibration reduction structure, has the following improvements:

[0013] (1) When the waves exceed the set sea conditions, the wave height and period parameters are measured by the wave height meter, the sea level is measured by the water level meter, and the data is transmitted to the control system in the form of electrical signals;

[0014] (2) The signal processor of the control system analyzes the data of step (1) and sets the horizontal displacement limit value Y2 of the vibration reduction structure according to the wave load amplitude F P and formula Calculate the stiffness coefficient k2 of the telescopic rod, and use the stiffness coefficient calculation formula The height l of the telescopic rod can be obtained, where E is the elastic modulus and I is the moment of inertia of the material cross section about the neutral axis of bending; then from the load frequency θ and the stiffness coefficient k2, according to the formula k2 = θ 2 m2 calculates the weight m2 of the required weight plate. If m2 is greater than the total weight of all weight plates, reset the horizontal displacement limit Y2 until the calculated telescopic rod height l and the required weight m2 of the weight plate are both within the adjustment range of the vibration reduction structure;

[0015] (3) The controller of the control system sends instructions to the hydraulic systems in the left and right slots according to the calculation results of the signal processor, and the hydraulic systems in the left and right slots respectively control their telescopic rods to be synchronously extended to a height of l. The controller sends instructions to the pulleys at the top of the telescopic rods in the left and right slots, and the pulleys in the left and right slots synchronously raise the counterweight plates with a total weight of m2 to the top of the telescopic rods;

[0016] (4) If the wave drops below the set sea condition, the controller sends a command to the pulleys at the top of the telescopic rods in the left and right slots, and the pulleys in the left and right slots synchronously lower the counterweight plate back to the top of the wave breakers. The controller of the control system sends a command to the hydraulic systems in the left and right slots, and the hydraulic systems in the left and right slots respectively control their telescopic rods to synchronously retract to the initial positions; if the wave still exceeds the set sea condition, repeat steps (1)-(3).

[0017] Furthermore, in step (3), the controller sends a command to the press in the middle groove, and the pressure rods on the left and right sides of the press respectively pass through the channels to press the telescopic rods opposite to them against the pad; in step (4), the controller sends a command to the press in the middle groove, and the pressure rods on the left and right sides of the press respectively disengage from the telescopic rods opposite to them.

[0018] Furthermore, in step (3), the controller turns on the power switch between the battery and the electromagnetic coil to adsorb each weight plate onto the telescopic rod; in step (4), the controller turns off the power switch between the battery and the electromagnetic coil.

[0019] The beneficial effects of the present invention are:

[0020] The vibration reduction structure disclosed in the present invention has a simple structure and is convenient and quick to construct. Based on the principle of a dynamic vibration absorber, it can significantly improve the stability of the hollow breakwater structure and protect it from vibration damage. Although it has a low cost, it has a significant vibration reduction effect.

[0021] To achieve the sliding of the counterweight plate along the telescopic rod, there must be a gap between the two, and the existence of the gap will cause the telescopic rod and the counterweight plate to have a relative displacement when the vibration reduction structure is reducing vibration, which has a great impact on the vibration reduction effect. The vibration reduction structure disclosed in the present invention is wound with an electromagnetic coil in the section of the upper part of the telescopic rod that is in contact with the counterweight plate. By controlling the connection or disconnection between the battery and the electromagnetic coil, the magnetism of the electromagnetic coil is controlled; by changing the magnitude of the current in the electromagnetic coil, the strength of the magnetism of the electromagnetic coil is controlled. When encountering extreme sea conditions, the pulley raises the counterweight plate to the upper part of the telescopic rod through a rope and then energizes the electromagnetic coil. The counterweight plate is adsorbed by the strong magnetic force generated by the electromagnetic coil, and no displacement occurs between the counterweight plate and the telescopic rod, forming a stable overall structure; when the marine environment returns to normal sea conditions, the electromagnetic coil is powered off, the magnetic force disappears, the counterweight plate and the telescopic rod are separated into two independent individuals, and the pulley descends the counterweight plate along the telescopic rod through a rope.

[0022] Pads for tightening the telescopic rod are arranged on the side walls of the left and right grooves opposite to the above-mentioned channels, and a press is installed in the middle groove, and the pressure rods on the left and right sides of the press pass through the corresponding channels respectively and are opposite to the telescopic rods in the left and right grooves. When encountering extreme sea conditions, after the telescopic rods are synchronously extended to a specified height, the press applies pressure to the telescopic rod opposite to it through the pressure rods on the left and right sides at the same time, so that it is pressed against the pads and cannot produce any lateral displacement, so that the telescopic rod and the hollow breakwater form a stable whole; when the marine environment returns to normal sea conditions, the pressure of the pressure rods on the left and right sides is removed, the telescopic rod and the pad are separated, and the telescopic rod is allowed to retract.

[0023] The vibration reduction method disclosed in the present invention can automatically adjust the extension and retraction of the telescopic rod and the lifting and lowering of the counterweight plate of the vibration reduction structure according to changes in sea conditions under extreme sea conditions, providing timely and effective protection for the hollow breakwater, thereby significantly reducing the horizontal vibration of the hollow breakwater. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the main structure of the vibration reduction structure when it is below the set sea condition;

[0025] Figure 2 It is a schematic diagram of the main structure of the vibration reduction structure when the sea condition exceeds the set value;

[0026] Figure 3 is a schematic diagram of the structure of the vibration reduction structure viewed from above;

[0027] Figure 4 It is a partial enlarged view of the electromagnetic coil part in the vibration reduction structure;

[0028] Figure 5 It is a schematic diagram of the press acting on the telescopic rod through the pressure rod;

[0029] Figure 6It is a schematic diagram of the signal transmission relationship and control relationship between various parts in the vibration reduction structure;

[0030] Figure 7 is an equivalent double-degree-of-freedom system diagram of a hollow breakwater after the vibration reduction structure disclosed in this embodiment is installed;

[0031] Figure 8 is a numerical model diagram of a hollow breakwater when the vibration reduction structure disclosed in this embodiment is not installed;

[0032] Fig. 9 It is a numerical model diagram of the permeable breakwater after the vibration reduction structure disclosed in this embodiment is installed. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] Before introducing the embodiments of the present invention in detail, the principle of the dynamic vibration absorber is briefly introduced as follows:

[0035] Simple harmonic load acts on a dual-degree-of-freedom system. According to the vibration equation under dynamic load, the displacement amplitude is solved as follows:

[0036]

[0037]

[0038] Where: D0 = (k 11 -θ 2 m1)(k 22 -θ 2 m2)-k 12 k 21

[0039] D1=(k 22 -θ 2 m2)F P1 -k 12 F P2

[0040] D2=-k 21 F P1 +(k 11 -θ 2 m1)F P2

[0041] When the load acts only on the main structure, that is, F P1 (t) = F P sinθt, the stiffness coefficient is: k 11=k1+k2, k 12 =k 21 =-k2, k 22 = k2; load amplitude is: F P1 =F P , F P2 =0;

[0042] Substituting in:

[0043]

[0044]

[0045] in:

[0046] When k2=θ 2 When m2:

[0047]

[0048] Y1=0

[0049]

[0050] Where Y1 and Y2 are the displacement amplitudes of the main body and the auxiliary part, k1 and k2 are the stiffness coefficients of the main body and the auxiliary part, and θ is the load frequency.

[0051] When there is no auxiliary structure to absorb vibration, the displacement amplitude of the main structure is:

[0052]

[0053] Where ω is the natural frequency of the structure,

[0054] This shows that when the main part of the breakwater is designed, k2 = θ 2 m2 method to design the auxiliary structure, the main body of the open-type breakwater and the auxiliary structure approximately constitute a double-degree-of-freedom system under the action of dynamic load, which can play a vibration reduction effect. Therefore, when designing the auxiliary structure, the allowable displacement amplitude Y2 of the auxiliary part and the external load amplitude F P Select the rod stiffness coefficient k2, and then determine the weight m2 of the counterweight plate by the load frequency θ and the stiffness coefficient k2.

[0055] In summary, according to the principle of dynamic vibration absorber, the air-permeable breakwater vibration reduction structure disclosed in this embodiment should comply with the following when working:

[0056] Telescopic rod stiffness:

[0057] Telescopic rod height:

[0058] Weight stack weight:

[0059] Embodiment 1, as Figure 1-5 As shown, this embodiment discloses a vibration reduction structure of a hollow breakwater, which is composed of piles 1 on both sides and a wave-breaking board 2 between the upper parts of the piles. The wave-breaking board can be regarded as a rigid body. Three grooves in a horizontal row are opened on the top of the breakwater wave-breaking board. The left and right grooves are connected to the middle groove through a transverse channel. A hydraulic system 8 and a telescopic rod 3 (equivalent to the piles of the vibration reduction structure) vertically extending upward out of the groove and controlled by the hydraulic system are installed at the bottom of the left and right grooves. Pads for tightening the telescopic rod are arranged on the side walls of the left and right grooves opposite to the above-mentioned channels. A press 12 is installed in the middle groove. The pressure rods 13 on the left and right sides of the press pass through the corresponding channels respectively and are opposite to the telescopic rods in the left and right grooves. Two or more counterweight plates are placed between the left and right grooves on the top of the wave-breaking board. 4. Both sides of each counterweight are respectively passed through the telescopic rods of the left and right grooves. The electromagnetic coils 10 are wound around the upper parts of the two telescopic rods, and the pulleys 9 that can pull the counterweights up and down are installed on the top. The wave height meter 5 and the water level meter 6 are installed on the wave-facing side of the wave-breaking board. The control system 7 is installed on the top of the wave-breaking board. The control system is electrically connected to the wave height meter and the water level meter and receives the data sent by them, and is electrically connected to the hydraulic system, the press and the pulley and controls their operation. The battery supplies power to the various components in the vibration reduction structure, and the power switch between the battery and the electromagnetic coil is controlled by the control system.

[0060] In this embodiment, the middle slot is located in the middle between the left and right slots. A cushion block 11 is installed at the end opposite to the compression rod and the telescopic rod. The length of the electromagnetic coil is greater than the sum of the heights of the weight plates. Figure 6 As shown, the control system consists of a signal processor and a controller, wherein the signal processor is electrically connected to the wave height meter and the water level meter and receives the data sent by them; the controller is electrically connected to the hydraulic system, the press and the pulley and controls their operation, and the power switch between the battery and the electromagnetic coil is controlled by the controller. The current between the battery and the electromagnetic coil is controlled by the controller. The pulley controls the lifting and lowering of the counterweight plate through the rope, the hydraulic system controls the extension and retraction of the telescopic rod, and the press controls the pressing rod to squeeze and separate the telescopic rod.

[0061] like Figure 7 As shown, the vibration reduction structure and the hollow breakwater body together constitute a dual-degree-of-freedom system under dynamic loads.

[0062] The following numerical simulation of the model structure under extreme sea conditions is performed to illustrate the effectiveness of the vibration reduction structure disclosed in this embodiment:

[0063] The open-type breakwater pile foundation uses 0.5m×0.5m prestressed concrete square piles with a length of 35m and an elastic modulus of E1=2.06×10 11 N / m 2 ; The size of the wave board is 4m×2.5m×0.2m, and the density is 2500kg / m 3 ; Elastic modulus of telescopic rod E2 = 2.678 × 10 11 N / m 2 , the cross-sectional size is 0.1m×0.1m; the wave parameters of extreme sea conditions are: wave height H=3m, period T=8s, wavelength 71m, wave number 0.088, water depth h=10m. The horizontal wave force of the wavebreak can be calculated by the wave pressure calculation formula:

[0064]

[0065] Substituting the data into the structure under the most unfavorable conditions F p =159.667kN; the allowable displacement of the vibration reduction structure is set to Y2 = 1.5m, according to the formula It can be seen that k2 = 106.445 kN / m, and the calculated height of the telescopic rod l is 3.98 m, and the load frequency From k2 = θ 2 m2 is calculated to be m2 = 172.74kg. The density of the weight plate is 6356kg / m 3 The high-density material is small in size. When it rises under extreme sea conditions, the wind load it receives is much smaller than the wave force on the breakwater, that is, the load amplitude F p2 Close to 0; by the formula It can be seen that the displacement of the lower structure is Y1 = 0.54m when the combined structure is not used under extreme sea conditions. This shows that the 172.74kg counterweight and 3.98m telescopic rod can eliminate the impact force of 159.667kN, which greatly ensures the stability of the open-type breakwater.

[0066] The numerical model is established based on the above parameters. Under extreme sea conditions, when the vibration reduction structure is not installed, the numerical model is as follows: Figure 8 As shown in the figure, the maximum displacement of the open-type breakwater under the action of waves is about 0.54m; after installing the vibration reduction structure, the numerical model is as follows Fig. 9 As shown in the figure, the amplitude of the vibration reduction structure is 1.5m, which meets the design requirements, and the maximum displacement of the hollow breakwater under the action of waves does not exceed 0.1m. This shows that the vibration reduction structure protects the main body of the hollow breakwater very well and avoids vibration damage to the hollow breakwater in extreme marine environments.

[0067] This embodiment also discloses a vibration reduction method for a hollow breakwater, using the above-mentioned vibration reduction structure:

[0068] (1) When the waves exceed the set sea conditions, the monitoring system measures the offshore water level and load frequency θ, that is, measures the wave height and period parameters through the wave height meter, measures the sea surface water level through the water level meter, and transmits the data to the control system in the form of electrical signals;

[0069] (2) The signal processor of the control system analyzes the data of step (1) and sets the horizontal displacement limit value Y2 of the vibration reduction structure according to the wave load amplitude F P and formula Calculate the stiffness coefficient k2 of the telescopic rod, and use the stiffness coefficient calculation formula The height of the telescopic rod can be obtained as l, where E is the elastic modulus, that is, the stress required to produce unit strain. Different materials have different elastic moduli, which can be found in the material manual. I is the moment of inertia of the material cross section about the neutral axis of bending, which can be calculated manually for conventional shapes. EI is the bending stiffness, which represents the ability of an object to resist its bending deformation; then, according to the load frequency θ and the stiffness coefficient k2, according to the formula k2=θ 2 m2 calculates the weight m2 of the required weight plate. If m2 is greater than the total weight of all weight plates, reset the horizontal displacement limit Y2 until the calculated telescopic rod height l and the required weight m2 of the weight plate are both within the adjustment range of the vibration reduction structure;

[0070] (3) The controller of the control system sends instructions to the hydraulic systems in the left and right slots according to the calculation results of the signal processor, and the hydraulic systems in the left and right slots respectively control their telescopic rods to be synchronously extended to a height of l. The controller sends instructions to the pulleys at the top of the telescopic rods in the left and right slots, and the pulleys in the left and right slots synchronously raise the counterweight plates with a total weight of m2 to the top of the telescopic rods;

[0071] (4) If the wave drops below the set sea condition, the controller sends a command to the pulleys at the top of the telescopic rods in the left and right slots, and the pulleys in the left and right slots synchronously lower the counterweight plate back to the top of the wave breakers. The controller of the control system sends a command to the hydraulic systems in the left and right slots, and the hydraulic systems in the left and right slots respectively control their telescopic rods to synchronously retract to the initial positions; if the wave still exceeds the set sea condition, repeat steps (1)-(3).

[0072] In step (3), the controller sends a command to the press in the middle groove, and the pressure rods on the left and right sides of the press respectively pass through the channels to press the telescopic rods opposite to them against the pad; in step (4), the controller sends a command to the press in the middle groove, and the pressure rods on the left and right sides of the press respectively disengage from the telescopic rods opposite to them.

[0073] In step (3), the controller turns on the power switch between the battery and the electromagnetic coil, and adsorbs each weight plate on the telescopic rod; in step (4), the controller turns off the power switch between the battery and the electromagnetic coil.

Claims

1. A vibration reduction structure of a hollow breakwater, characterized in that: Three grooves in a horizontal row are opened on the top of the breakwater wave plate, and the left and right grooves are connected with the middle groove through a horizontal channel. A hydraulic system and a telescopic rod controlled by the hydraulic system and extending vertically upward out of the groove are installed at the bottom of the left and right grooves. Pads for tightening the telescopic rod are arranged on the side walls of the left and right grooves opposite to the above-mentioned channels. A press is installed in the middle groove. The pressure rods on the left and right sides of the press respectively pass through the corresponding channels and are opposite to the telescopic rods in the left and right grooves. More than two counterweight plates are placed between the left and right grooves on the top of the wave plate. The two sides are respectively passed through the telescopic rods of the left and right grooves, the upper parts of the two telescopic rods are wound with electromagnetic coils, and the tops are installed with pulleys that can pull the weight plates up and down, the wave height meter and the water level meter are installed on the wave-facing side of the wave-breaking board, and the control system is installed on the top of the wave-breaking board. The control system is electrically connected to the wave height meter and the water level meter and receives the data sent by them, and is electrically connected to the hydraulic system, the press and the pulley and controls their operation. The battery supplies power to the various components in the vibration reduction structure, and the power switch between the battery and the electromagnetic coil is controlled by the control system; The middle slot is located in the middle between the left and right slots; The control system consists of a signal processor and a controller, wherein the signal processor is electrically connected to the wave height meter and the water level meter and receives the data sent by them; the controller is electrically connected to the hydraulic system, the press and the pulley and controls their operation, and the power switch between the battery and the electromagnetic coil is controlled by the controller.

2. The vibration reduction structure of the hollow breakwater according to claim 1 is characterized in that: Install a cushion block at the end of the compression rod opposite to the telescopic rod.

3. The vibration reduction structure of the hollow breakwater according to claim 1 is characterized in that: The length of the electromagnetic coil is greater than the sum of the heights of the weight plates.

4. The vibration reduction structure of the hollow breakwater according to claim 1 is characterized in that: The current between the battery and the electromagnetic coil is controlled by the controller.

5. A vibration reduction method for a hollow breakwater, using the vibration reduction structure according to claim 1, characterized in that: (1) When the waves exceed the set sea conditions, the wave height and period parameters are measured by the wave height meter, the sea level is measured by the water level meter, and the data is transmitted to the control system in the form of electrical signals; (2) The signal processor of the control system analyzes the data of step (1) and sets the horizontal displacement limit value Y2 of the vibration reduction structure according to the wave load amplitude F P and formula Calculate the stiffness coefficient k2 of the telescopic rod, and use the stiffness coefficient calculation formula The height l of the telescopic rod can be obtained, where E is the elastic modulus and I is the moment of inertia of the material cross section about the neutral axis of bending; then from the load frequency θ and the stiffness coefficient k2, according to the formula k2 = θ 2 m2 calculates the weight m2 of the required weight plate. If m2 is greater than the total weight of all weight plates, reset the horizontal displacement limit Y2 until the calculated telescopic rod height l and the required weight m2 of the weight plate are both within the adjustment range of the vibration reduction structure; (3) The controller of the control system sends instructions to the hydraulic systems in the left and right slots according to the calculation results of the signal processor, and the hydraulic systems in the left and right slots respectively control their telescopic rods to be synchronously extended to a height of l. The controller sends instructions to the pulleys at the top of the telescopic rods in the left and right slots, and the pulleys in the left and right slots synchronously raise the counterweight plates with a total weight of m2 to the top of the telescopic rods; (4) If the wave drops below the set sea condition, the controller sends a command to the pulleys at the top of the telescopic rods in the left and right slots, and the pulleys in the left and right slots synchronously lower the counterweight plate back to the top of the wave breakers. The controller of the control system sends a command to the hydraulic systems in the left and right slots, and the hydraulic systems in the left and right slots respectively control their telescopic rods to synchronously retract to the initial positions; if the wave still exceeds the set sea condition, repeat steps (1)-(3).

6. The vibration reduction method of the hollow breakwater according to claim 5, characterized in that: In step (3), the controller sends a command to the press in the middle groove, and the pressure rods on the left and right sides of the press respectively pass through the channels to press the telescopic rods opposite to them against the pad; in step (4), the controller sends a command to the press in the middle groove, and the pressure rods on the left and right sides of the press respectively disengage from the telescopic rods opposite to them.

7. The vibration reduction method of the hollow breakwater according to claim 5, characterized in that: In step (3), the controller turns on the power switch between the battery and the electromagnetic coil, and adsorbs each weight plate on the telescopic rod; in step (4), the controller turns off the power switch between the battery and the electromagnetic coil.

Images