CN106836117A - A kind of porous floating breakwater - Google Patents

Abstract

The invention discloses a porous floating breakwater, which comprises several breakwater units connected in sequence. The breakwater unit comprises a first buoyancy tank, a second buoyancy tank, connecting rods and two layers of vertical plates. The first buoyancy The tank and the second buoyant tank are rigidly connected by connecting rods, the first buoyant tank and the second buoyant tank are connected to the mooring counterweight through anchor chains for mooring, and the two vertical plates are fixedly installed on the connecting rods. The straight plates are all provided with a number of water holes, and the opening rate of the water holes of the vertical plates is 9% to 11%. The porous floating breakwater of the present invention has good wave dissipation effect, small structural stress, good safety, simple structure, convenient construction and wide application range, and has important practical significance for wave prevention in port engineering.

Description

A porous floating breakwater

technical field

The invention relates to a porous floating breakwater and belongs to the field of breakwaters.

Background technique

The breakwater is an important port and coastal engineering structure, mainly used to defend against the invasion of waves on the port waters, to provide stable and safe berthing conditions and operating waters in the port, and to improve the design conditions of the hydraulic structures in the port. Protection of port hydraulic structures. In addition, on sandy or muddy coasts, breakwaters can also reduce or prevent sediment from entering the port. For frozen ports, breakwaters can also reduce the flow of ice outside the port into the port. The structural types of breakwaters mainly include slope type, vertical type, hybrid type, air-through type and floating type, etc., among which the first three are traditional bottom-sitting type breakwaters. The traditional bottom-seat breakwater can better protect the waters in the port and has a long service life. However, the bottom-seat breakwater has inevitable limitations: with the increase of project water depth and the deterioration of foundation conditions, the project cost increases sharply, and The difficulty of construction is increased; the water circulation in the shelter area is restricted, and sediment deposition and water pollution in the port are prone to occur. At the same time, the pile-based permeable breakwater has poor ability to adapt to changes in tidal levels, and the shielding effect is difficult to control.

With the development of comprehensive needs such as coastal environmental protection, tourism and aquaculture, people's ideas about coastal and port development are undergoing major changes. In order to meet the needs of deep water, weak foundation, introduction of seawater exchange to improve the water quality environment in the port and low cost, the port engineering structure will develop into new structural types such as air-permeable structure, energy dissipation structure and multi-functional structure.

In recent years, floating breakwaters have drawn close attention from domestic and foreign port, coastal and marine engineering circles, because it has the following advantages compared with traditional bottom-sitting breakwaters: (1) When the water depth is large, the floating breakwaters are greatly reduced The project cost is generally relatively low; (2) No foundation treatment is required during construction, and it is not limited by foundation conditions, which reduces the difficulty of construction; (3) It has a strong water exchange function, which can prevent seawater pollution and prevent It affects the sediment movement and fish migration, and protects the aquatic biological environment in the shelter; (4) The amount of work is small, the construction is simple and fast, and it is easy to demolish and adjust the layout; (5) The floating body can rise and fall with the change of the tide level, and can adapt to large tidal ranges The sea area is beautiful. In view of the above advantages, the floating breakwater can be used as a permanent building or a temporary building, and has broad application prospects in the following fields: (1) Constructing a deep-water wharf in a natural deep-water harbor with good wind shelter conditions, in order to prevent perennial dominant wind and waves A small number of floating breakwaters can be installed in suitable areas to achieve better effect of sheltering from wind and waves; (2) floating breakwaters can be used as temporary berthing docks for ships; (3) floating breakwaters can protect aquaculture, Water areas such as bathing beaches, in order to achieve the dual effect of saving investment and maintaining good water quality; (4) The construction site of offshore engineering can be temporarily covered by floating breakwaters to increase the number of construction days, shorten the construction period, and improve efficiency; (5) In the military, the floating breakwater can be used to cover the waters of the sea motor wharf, and it is also an ideal structure type; (6) the floating breakwater can be used as a wave-proof measure for disaster prevention and emergency at sea. However, there are also many factors that limit the application of floating breakwaters, such as the shielding effect is not as good as that of the bottom-seat breakwater, the wave dissipation effect is poor when the wave period is long, and the dynamic response under the action of waves will lead to fatigue damage of the structure and large mooring force As a result, maintenance requirements are high, and the safety of the floating breakwater structure itself is difficult to guarantee under extreme storm conditions.

The floating breakwater is composed of a floating body and an anchoring system, and the wave is dissipated through the interaction between the floating body and the wave. According to the wave dissipation principle of the floating breakwater structure, the floating breakwater can be divided into wave energy reflection type (such as buoy box type, buoy type floating breakwater type), wave energy loss type (such as bamboo raft, waste tires and other floating raft type floating type) breakwater) and reflection-loss hybrid (such as fence type, floating box fence type floating breakwater) three categories.

The following is an introduction to the research results and development of floating breakwater structures, focusing on the analysis of the wave dissipation principle, wave dissipation performance and structural stress of different structural types of floating breakwaters.

Buoyant type (pontoon type) floating breakwater

The traditional pontoon-type floating breakwater mainly uses pontoons to reflect incident wave energy to the open sea to reduce transmitted waves. It is generally made of steel plates or reinforced concrete. The width of a single pontoon generally ranges from 8 to 16m and the depth of entry Generally 1.5 ~ 4.0m. Among the pontoon type floating breakwaters, the structure is the simplest and the most widely used is the single pontoon type floating breakwater. In order to improve the wave dissipation performance of the pontoon-type floating breakwater and expand the application range of the floating breakwater, scholars at home and abroad have improved the structure of the pontoon from the perspectives of increasing wave reflection and wave energy loss. Box-vertical slab, pontoon-horizontal slab and pontoon-other wave energy loss structural floating breakwater, etc.

(1) Multi-pontoon floating breakwater

Compared with the single pontoon type floating breakwater, the multi-pontoon type can improve the wave dissipation performance. According to the two-dimensional potential flow theory, Williams et al. applied the boundary element method to carry out numerical simulation research on the hydrodynamic characteristics of the floating breakwater composed of two rigidly connected buoyant boxes and two unconnected buoyant boxes. It shows that the wave reflection coefficient of the double-pontoon floating breakwater is largely determined by the width of the structure, the draft, the distance between the two pontoons and the rigidity of the anchor chain. Koftis and Prinos applied the unsteady Reynolds-averaged N-S method (URANS) to solve the problem of the interaction between waves and fixed double pontoon floating breakwaters, and studied the influence of the relative width of the levee and the relative spacing of the front and rear pontoons on the wave dissipation performance , the results show that the transmission coefficient decreases with the increase of the relative width, and the change of the transmission coefficient with the relative spacing of the front and rear pontoons is not monotonous. Diamantoulaki et al. used three-dimensional hydrodynamic analysis combined with static and dynamic analysis of anchor chains to study the hydrodynamic characteristics of different types of double pontoon floating breakwaters. The results show that the wave dissipation effect of the front and rear pontoons is better than that of The situation when the single pontoon and the front and rear pontoons are not connected; only when the distance between the front and rear pontoons is increased in the medium wave frequency range can the wave dissipation effect be improved; when the distance between the front and rear pontoons increases, the maximum anchor chain force tends to decrease . Syed and Mani also used the boundary element method to analyze the wave dissipation performance of a floating breakwater composed of three rigidly connected pontoons. The research results show that the spacing of pontoons has a significant impact on the wave transmission coefficient and reflection coefficient.

(2) Floating tank - vertical slab floating breakwater

Floating tank—Vertical slab floating breakwater increases wave reflection and interferes with the movement of water bodies near it through vertical inserts, thereby improving wave dissipation performance. The common types are π and T. Christian has conducted a series of experimental studies on floating breakwaters connected with vertical panels. The results show that in general, the greater the penetration depth of the panels, the smaller the transmission coefficient. However, when the penetration depth of the panels is too large, especially under short-period waves The induced radiation waves will increase the transmission coefficient. Gesraha used the characteristic function expansion method to carry out numerical simulation research on the π-type floating breakwater connected with vertical plates on both sides. The transmission coefficient will increase when acting on short-period waves. Ruol et al. conducted a series of physical model test studies on 8 π-type floating breakwaters of different sizes (anchored by anchor chains and anchored by vertical guide piles), and introduced the relative period (the ratio of the incident wave period to the natural period of the structure heave) Parameters The formula for calculating the transmission coefficient of π-type floating breakwaters is proposed. Alizadeh et al. compared the wave dissipation effects of the π-shaped floating breakwater anchored by vertical guide piles and the T-shaped floating breakwater with only one insert plate connected to the lower part of the pontoon through physical model tests. Significantly better than T-type. Koriam and Rageh specifically studied the influence of vertical boards on the wave dissipation performance of floating breakwaters through physical model tests. The transmission coefficient can be less than 0.25 when inserting the board.

(3) Floating tank—horizontal slab floating breakwater

Buoyancy—Horizontal Plate Floating Breakwater uses the horizontal plate at the bottom of the pontoon to interfere with the movement of water around it and increase the overall stability of the structure, thereby improving wave dissipation performance. Ikesue et al. proposed a double pontoon type floating breakwater with inner and outer wings, and calculated its transmission coefficient using a wave numerical tank. The research results show that the inner and outer wings have a significant impact on the wave dissipation performance of the floating breakwater, with The wave dissipation effect of the double pontoon type floating breakwater of the inner and outer wings is better than that of the single pontoon type floating breakwater of the same size. Dong Huayang conducted physical model tests and numerical simulation studies on the floating breakwater with horizontal slabs installed at the bottom of the single pontoon. The results show that when the vertical guide piles are anchored, setting a layer of horizontal slabs at the bottom of the pontoon can reduce the transmission coefficient by about 0.3. , the transmission coefficient continues to decrease, but the reduction range is not obvious. The buoy box with a layer of slab-type vertical guide piles anchored at the bottom of the pontoon-horizontal slab floating breakwater has an ideal wave dissipation effect; when the anchor chain is anchored, set a The transmittance coefficient of the laminate can be reduced by 0.2 at most, and the motion response and anchor chain force are smaller than those of the single pontoon type floating breakwater. Xiao Xiao, Wang Yongxue and others used the boundary element method to study the interaction between waves and double pontoon-horizontal slab floating breakwaters. The structure includes a layer of horizontal slab placed under the double pontoon. The numerical simulation results show that the total width of the pontoon Under certain conditions, the double pontoon-horizontal slab floating breakwater has a better wave dissipation effect than the single box-horizontal slab floating breakwater, but the movement amplitude is larger and the force on the anchor chain is larger. Yang Biao et al ^. conducted a physical model test on a floating breakwater with horizontal slabs installed at the lower part of double pontoons. The results showed that the wave dissipation effect of two slabs is better than that of one slab, and its transmission coefficient is lower than that of the case without horizontal slabs. It can be reduced by about 0.4 at most; when the relative width is greater than 0.30, the transmission coefficient can be controlled below 0.35, and the motion response is also significantly reduced, but the force on the anchor chain will increase.

(4) Floating tanks - other structural floating breakwaters with loss of wave energy

The combination of buoyancy tanks and other lossy wave energy structures can improve the wave dissipation performance of floating breakwaters, because the combined structure changes the structure of buoyant tanks from wave energy reflection to wave energy reflection-loss hybrid floating breakwaters. Wave energy loss structures mainly include fence structures, truss structures, membrane structures, and air chamber structures.

The pontoon-type floating breakwater combined with a pontoon and a fence or truss structure uses a fence structure or a truss structure to enhance water turbulence, break waves and increase wave energy loss, thereby improving wave dissipation performance. Mani proposed a Y-shaped floating breakwater in which cylinders are installed at equal intervals at the bottom of the floating tank. A row of cylinders at the bottom can attenuate the wave energy. The research results show that the floating breakwater can reduce the transmission coefficient when the relative width is about 0.15 If it is less than 0.5, it reduces the requirement for the width of the buoy when the wave period is long. Murali and Mani proposed a "cage" floating breakwater consisting of front and rear rows of pontoons and close-packed circular tubes below. The research results show that the floating breakwater can reach most of the floating breakwater structures when the relative width is 0.15 Wave dissipation effect when the relative width is 0.4. Huang Zhenhua et al. compared the hydrodynamic characteristics of the slotted structure connected to the bottom of the floating tank through physical model tests, and the results showed that the slotted structure connected to the bottom of the floating tank can significantly improve the wave dissipation effect of the floating breakwater without Increased motion response of floating banks. Matsunaga et al. studied the wave dissipation performance of the floating breakwater designed by Saiki Iron and Steel Company in Japan. The floating breakwater is composed of a pontoon and front and rear steel trusses. wave effect.

Single-layer or multi-layer membrane structures (nylon membrane, glass fiber cloth, etc.) can be used as floating breakwaters to dissipate waves and protect related waters. Arranging a single-layer or multi-layer film structure at the bottom of the floating tank can improve the wave dissipation performance of the floating breakwater. Hermanson proposed a pontoon-type floating breakwater with a bottom connected to a single-layer film. Experimental results show that the wave dissipation effect of the pontoon-type floating breakwater with a bottom connected to a single-layer film is better than that without a film. The transmission coefficient The average reduction is about 12%, and the reduction can be as high as 17%. Sung Tai Kee conducted a numerical simulation study on the floating box-type floating breakwater with a three-layer membrane structure connected at the bottom. wave effect.

(5) Floating raft type floating breakwater

The floating raft type floating breakwater is a wave energy loss type floating breakwater, which mainly uses the friction between the floating body and the water body near the water surface to interfere with the movement of the water body near the water surface to attenuate the incident waves. The floating raft type floating breakwater is easy to manufacture and maintain, and compared with the buoy box type and buoy type floating breakwater, the cost is relatively low, but the wave dissipation effect is relatively poor, and the width of the floating raft structure generally needs to be about double the wavelength to effectively Play a role in eliminating waves. There are relatively many researches and applications on waste tire type floating breakwaters at home and abroad. The waste tire type floating breakwater is divided into Wave-Maze type, Goodyear type and Wave-Guard type according to different layout types. The Wave-Guard type uses rods to connect the tires into a rigid whole. Compared with other types of waste tire type floating breakwaters Type breakwater has better wave dissipation effect. Wu Weideng et al. improved the structure of the steel pipe-tyre floating breakwater from the aspects of raft body stiffness, inclination, wave-retaining area, and natural frequency, which can increase the reflection and consumption of wave energy by the floating raft, and can be used in more unfavorable conditions. Under the incident wave condition, the transmission coefficient of the floating raft can be at least 0.22. Yu Lilun and Yu Yijun in Taiwan conducted experimental research on a waste tire-type floating breakwater, which showed that the floating breakwater has a better wave dissipation effect on sea conditions with small current velocity and high wave height. Zhang Yu and Wang Yongxue conducted experimental research on the waste tire floating breakwater, and the results showed that within the test range, when the embankment width is greater than 0.6 times the wavelength, the transmission coefficient is less than 0.5; The effect is not obvious; the anchor chain force increases with the increase of wave height and anchor chain stiffness, and decreases with the increase of anchor chain drag length.

For the floating raft type floating breakwater, in addition to the waste tire type, there are other types of floating raft type floating breakwater proposed. Wu Jingping and others imitated the structural form of aquatic plants "floating" and designed a new form of breakwater, which flexibly connected multiple circular planks into one and laid them flat on the water surface. When the way of mooring underwater is fixed, the effect of wave dissipation is better than that of mooring on the shore. Wu Xuan and Wu Songren conducted a physical model test study on the bamboo raft floating breakwater used to shield the construction area of the wharf. The test results show that the bamboo raft floating breakwater has certain engineering practical value as a wave dissipation measure. The wave elimination effect is obvious. Hegde et al. carried out a physical model test study on a floating raft-type floating breakwater formed by horizontally interlaced multi-layer PVC circular pipes. In the test range, when the relative width of the floating breakwater is 1.0, the transmission coefficient is about 0.6.

(6) Other types of floating breakwaters

In addition to a variety of floating box (pontoon) and floating raft floating breakwater structures, there are also other structural types of floating breakwaters proposed, such as A-frame floating breakwaters, plate-network and porous structure floating breakwaters, etc. . The A-frame floating breakwater was proposed by Canadian scholars, and its design principle is to make the floating dike structure have a large moment of inertia. Dong Guohai and Zheng Yanna proposed a slab-net floating breakwater composed of slabs, nets and sinkers, and studied the effect of the slab-net floating breakwater under the action of pure waves and the combined action of waves and currents through physical model tests. The research results show that this kind of floating breakwater has a good wave dissipation effect, and it can be applied to deep-sea aquaculture, but the specific design parameters need to be determined according to the actual local wave and current conditions. Wang Huanyu and Sun Zhaochen, on the basis of considering blocking reflection, turbulent energy consumption and wave peak dissipation, proposed a porous structure floating embankment assembled by multi-layer and multi-diamond modules, and carried out a physical model test on the structural floating embankment Research, the research results show that the structure of the floating embankment has more wave energy loss, less wave reflection, good wave dissipation effect and small wave force. The design methods and research ideas of these floating breakwater structures provide positive references for further research on the structure types of floating breakwaters and improving the wave dissipation effect of floating breakwaters.

Double pontoon-horizontal slab floating breakwater, the structure is a rigid member composed of two floating square boxes and two layers of horizontal plates, connected to the bottom of the water through anchor chains to form a floating breakwater, its wave dissipation performance is related to the relative width, relative The wave height is related to factors such as the stiffness of the anchor chain. The existing floating breakwater structure mainly has the following disadvantages:

(1) The existing floating breakwater has the disadvantage of poor wave dissipation effect, especially when the wave period is long. This is because when the wave period is longer, the floating breakwater moves more with the wave, and its reflection effect on the outer sea wave and the wave energy loss effect are weakened, and the wave penetrating behind the embankment becomes larger;

(2) When the wave height is high, the structure of the floating breakwater is subjected to a large force, and it is difficult to guarantee the safety of the structure during the service period. This is because floating breakwaters are generally anchored by anchor chains or vertical guide piles. Under the action of waves, the floating breakwater moves with the waves. When large waves act, the floating breakwater will move violently. Limiting the movement of the pontoon will generate a lot of force on the structure. security is difficult to guarantee.

(3) For some complex structure floating breakwaters with better wave dissipation performance, although there are many structural types proposed at home and abroad, the structure of floating breakwaters is subject to large wave forces during large waves, and the safety of the structure itself is difficult to guarantee. reduced sex. For example, for the double pontoon-horizontal slab floating breakwater, although its wave dissipation effect is improved compared with the traditional single pontoon floating breakwater, the force on the anchor chain increases, and the wave force on the lower horizontal plate is also large, and the structural Reduced security.

Contents of the invention

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a porous floating breakwater, which has good wave dissipation effect, small structural force, good safety, simple structure, convenient construction, and wide application range, which is suitable for port engineering Anti-wave has important practical significance.

Technical solution: In order to solve the above-mentioned technical problems, a porous floating breakwater of the present invention comprises several breakwater units connected in sequence, and the breakwater unit comprises a first buoyancy tank, a second buoyancy tank, a connecting rod and two vertical layers. Straight plates, the first buoyant tank and the second buoyant tank are rigidly connected by connecting rods, the first buoyant tank and the second buoyant tank are connected to the mooring counterweight through anchor chains for mooring, and the two vertical plates are fixedly installed on the On the connecting rod, several water holes are arranged on the two vertical plates, and the opening ratio of the water holes of the vertical plates is 9% to 11%.

Preferably, the first pontoon and the second pontoon have the same shape and a width of B, the distance between the first pontoon and the second pontoon is D, and the range of D/2B is 1.0-1.5.

Preferably, the two vertical plates have holes within the height range of the first pontoon tank and the second pontoon tank, and the opening ratio of the water holes of the vertical plates is 9% to 11%.

As a preference, a horizontal baffle is installed at both ends of the two vertical plates respectively, and the horizontal baffle and the vertical plate form a "well" shape, and several water holes are also arranged on the horizontal baffle, and the holes of the water holes The porosity is 9% to 11%.

As a preference, external threads are provided on the connecting rod, and the vertical plate is locked on the connecting rod through the first locking nuts on both sides. Grooves are arranged at both ends of the vertical plate, and the horizontal baffle plate Bosses are extended at both ends of the body, the bosses pass through the grooves, an L-shaped connector is connected between the boss and the vertical plate, and the L-shaped connector is connected to the boss and the vertical plate by bolts.

Preferably, the vertical plate is arc-shaped.

Preferably, the four corners of the vertical plate are provided with connecting bosses, the connecting bosses are connected with support rods through bolts, the supporting rods are connected with the connecting sleeve, and the connecting sleeve is locked on the connecting rod through the second locking nut .

Beneficial effects: the porous floating breakwater of the present invention has good wave dissipation effect, small structural stress, good safety, simple structure, convenient construction and wide application range, and has important practical significance for wave prevention in port engineering. Porous floating breakwaters can be used in waters with medium wave intensity, in port docks, offshore construction, mariculture, bathing beaches and other fields. The advantages of convenient maintenance will play a positive role in promoting the construction of my country's ports and coastal projects, the development and utilization of coastal resources and environmental protection; the popularization and application of porous floating breakwaters will bring great social and economic benefits.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

Figure 2 is a side view of the present invention.

Fig. 3 is a schematic structural view of a "well"-shaped vertical plate in the present invention.

Fig. 4 is a schematic structural view of the vertical plate in the present invention in an arc shape.

Fig. 5 is a comparative relationship diagram between the present invention and the existing single pontoon type floating breakwater.

Fig. 6 is a comparative relationship diagram of the effect of the opening of the vertical plate structure on the force of the structure in the present invention.

detailed description

As shown in Fig. 1 and Fig. 2, a kind of porous floating breakwater of the present invention comprises several breakwater units connected in sequence, adjacent breakwater units can be flexibly connected by hinges, and said breakwater unit comprises a first buoyancy tank 1 , the second pontoon 4, connecting rod 2 and two layers of vertical plates 3, the first pontoon 1 and the second pontoon 4 are rigidly connected by the connecting rod 2, the first pontoon 1 and the second pontoon 4 are all The anchor hole 5 and the anchor chain 6 are connected to the mooring counterweight 7 for mooring. The opening rate of the water hole of the straight plate is 9% to 11%. When there are too many openings on the vertical plate 3, the propagation of waves cannot be well blocked, and the energy dissipation effect is not good. Straight plate 3 bears a large force and is easy to wear and tear, which reduces the safety and durability of the structure, and has poor practicability for long-term use. After long-term research, when the opening ratio of the water hole is 9% to 11%, the vertical The energy dissipation effect of the board is good, and the safety and durability of the vertical board are good, and the service life is long.

In the present invention, the shape of the first pontoon 1 and the second pontoon 4 are consistent, the width is B, the distance between the first pontoon 1 and the second pontoon 4 is D, and the range of D/2B is 1.0 to 1.5, and when the relative spacing D/2B of the front and rear pontoons is 1.0 to 1.5, the wave transmission coefficient of the double pontoon buoy is the smallest, and the wave dissipation effect of the double pontoon buoy is the best. The vertical plate 3 is perforated within the height range of the first pontoon tank 1 and the second pontoon tank 4, and when the vertical plate between the double pontoon tanks is perforated within the full plate height range, the wave transmission coefficient of the buoyant embankment is greater than that of the vertical slab. The situation when the straight plate opens holes within the height range of the pontoon. Within the test range, compared with the situation when the vertical slabs are perforated within the height range of the buoy, the wave transmission coefficient of the buoy increases by an average of 5.6% when the vertical slabs are perforated within the full height range of the slab. Therefore, in order to improve the wave dissipation performance of the porous floating breakwater, the porous vertical plate structure arranged between the double pontoon tanks should open holes within the height range of the pontoon tanks.

In the present invention, a horizontal baffle 9 is installed at both ends of the two vertical plates 3 respectively, and the horizontal baffle 9 and the vertical plate 3 form a "well" shape. The water hole, the opening ratio of the water hole is 9% to 11%. By providing a "well"-shaped wave dissipation structure between the first buoyancy tank 1 and the second buoyancy tank 4, waves can be reduced in multiple directions, greatly reducing the impact of waves. The connecting rod 2 is provided with an external thread, and the vertical plate 3 is locked on the connecting rod 2 by the first locking nuts 10 on both sides, and grooves are arranged at both ends of the vertical plate 3, The two ends of the cross baffle 9 extend with a boss, the boss passes through the groove, and an L-shaped connector 8 is connected between the boss and the vertical plate 3, and the L-shaped connector 8 is connected to the boss and the vertical plate by bolts. Board 3 is connected. Through the L-shaped parts, it is very convenient to install and disassemble the "well" shaped wave dissipation structure, and all the structures can be installed and adjusted on site, and the transportation and construction are very convenient.

In the present invention, the vertical plate 3 is arc-shaped, and the four corners of the vertical plate 3 are provided with connecting bosses, and the connecting bosses are connected with support rods 11 by bolts, and the support rods 11 and the connecting sleeves 12 The connecting seat bolts on the top are connected by bolts, and the connecting sleeve 12 is locked on the connecting rod 2 through the second locking nut 14. The whole structure is similar to an umbrella structure. For the entire arc-shaped vertical plate 3, because the wave action will be out of sync, the floating embankment structure will become smaller with the wave movement, and the wave dissipation effect will be better. And because the vertical plate is arc-shaped, the strength structure of the entire vertical plate 3 is also well improved, and the service life will be greatly enhanced.

The front and rear pontoons are combined with the porous structure. On the one hand, the double pontoon structure makes the moment of inertia of the floating breakwater larger, the movement of the floating breakwater with the waves becomes smaller, and the reflection of the floating breakwater to waves is enhanced. On the other hand, the wave is transparent The front buoyancy tank is much lost by the porous vertical plate between the double buoyancy tanks, and the perforated vertical plate between the double buoyancy tanks enhances the wave energy loss. The porous floating breakwater constitutes a wave energy reflection-loss hybrid structure, which improves the wave dissipation effect of the floating breakwater from two aspects: increasing wave reflection to the outer sea and enhancing wave energy loss. Simple and easy to build.

The wave transmission coefficient C _t is an important indicator of the wave dissipation effect of the floating breakwater, which is the ratio of the transmitted wave height behind the embankment to the incident wave height in front of the embankment. The smaller the wave transmission coefficient C _t is, the better the wave dissipation effect of the floating breakwater is. The wave transmission coefficient of the porous floating breakwater was compared with that of the existing single pontoon floating breakwater through the two-dimensional flume physical model test, as shown in Fig. The comparison relationship between the wave transmission coefficient of the porous floating breakwater and the existing single pontoon floating breakwater, Figure b shows the comparison between the wave transmission coefficient of the porous floating breakwater and the existing single pontoon floating breakwater when the wave height is 2.5m relation. The wave transmission coefficient of the porous floating breakwater is reduced by 0.16 to 0.25 compared with the existing single pontoon floating breakwater, with an average relative reduction of 33.5%. The wave dissipation effect of the porous floating breakwater is comparable to that of the existing single pontoon floating Much improved compared to breakwaters.

Fig. 6 is the comparison relation of the wave force F _b on the vertical plate on the first floor when the vertical plate between the double pontoons is opened and not opened when the wave height is 2.5m (the positive force means the same positive direction as the wave direction Horizontal force, reverse force represents the reverse horizontal force opposite to the direction of the wave), where a represents the relationship diagram between the forward force and the wave period, and b represents the relationship diagram between the reverse force and the wave period. When two layers of vertical slabs are arranged between the double pontoon tanks, the vertical slabs open 10.7% of the holes within the height of the pontoon tanks compared with the case of no holes, and the positive wave force on the first layer of vertical slabs is reduced by an average of 10.1%. Reverse wave forces were reduced by an average of 16.7%. Compared with the vertical slab without openings, when the vertical slab is open, the forward and reverse wave forces on the vertical slab are significantly reduced, and the vertical slab opening can improve the safety of the floating breakwater structure .

Since the porous floating breakwater constitutes a wave energy reflection-loss hybrid structure, the wave dissipation effect of the floating breakwater is greatly improved from two aspects: increasing the wave reflection to the outer sea and enhancing the wave energy loss. Compared with the single floating box type floating breakwater, the improvement is 33.5%; the vertical plate openings can significantly reduce the wave force on the structure, and the vertical plate openings can improve the safety of the structure. At the same time, the porous floating breakwater has a simple structure and is easy to construct, which expands the scope of application of the floating breakwater, and can be applied to waters with medium wave intensity, and can be used in ports, offshore construction, mariculture, bathing beaches and other fields.

The wave energy reflection-loss hybrid structure of the porous floating breakwater greatly improves the wave dissipation effect of the floating breakwater by increasing the wave reflection to the outer sea and enhancing the wave energy loss. At the same time, the structure has small stress, good safety, simple structure, It is easy to construct and can be applied to waters with medium wave intensity. It can be used in port terminals, offshore construction, mariculture, bathing beaches and other fields. It can play an uninterrupted exchange of water bodies inside and outside the port, reduce siltation in the port, and is limited by water depth. Construction is quick and easy to maintain. The advantages of convenience play a positive role in promoting the construction of my country's ports and coastal projects, the development and utilization of coastal resources and environmental protection.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (7)

1. A kind of porous floating breakwater, it is characterized in that: comprise several breakwater units connected in sequence, adjacent breakwater units can be flexibly connected by hinges, and described breakwater unit comprises first pontoon, second pontoon, connection Rods and two layers of vertical plates, the first buoyant tank and the second buoyant tank are rigidly connected by connecting rods, the first buoyant tank and the second buoyant tank are connected to the mooring counterweight through anchor chains for mooring, and the two vertical buoyant tanks The straight plates are fixedly installed on the connecting rods, and several water holes are arranged on the two vertical plates, and the opening ratio of the water holes on the vertical plates is 9% to 11%. 2. The porous floating breakwater according to claim 1, characterized in that: the shape of the first pontoon and the second pontoon are consistent, the width is B, and the distance between the first pontoon and the second pontoon The spacing is D, and the range of D/2B is 1.0 to 1.5. 3. The porous floating breakwater according to claim 2, characterized in that: the vertical plate has holes in the height range of the first pontoon and the second pontoon, and the opening of the water hole of the vertical plate The rate is 9% to 11%. 4. The porous floating breakwater according to claim 1, characterized in that: the two ends of the two vertical plates are respectively equipped with a horizontal baffle, and the horizontal baffle and the vertical plate form a "well" shape. A number of water holes are also arranged on the baffle, and the opening ratio of the water holes is 9% to 11%. 5. The porous floating breakwater according to claim 4, characterized in that: the connecting rod is provided with an external thread, and the vertical plate is locked on the connecting rod through the first locking nuts on both sides , grooves are provided at both ends of the vertical plate, bosses are extended at both ends of the horizontal baffle, the boss passes through the groove, and an L-shaped connector is connected between the boss and the vertical plate, and the L-shaped connector is connected by bolts. The connecting piece is connected with the boss and the vertical plate. 6. The porous floating breakwater according to claim 1, characterized in that: said vertical plates are arc-shaped. 7. The porous floating breakwater according to claim 6, characterized in that: the four corners of the vertical plate are provided with connecting bosses, the connecting bosses are connected with support rods through bolts, and the support rods are connected with the connecting sleeves , the connecting sleeve is locked on the connecting rod through the second locking nut.