JP4336323B2 - Seawater exchange caisson - Google Patents

Description

  The present invention relates to improvement of a seawater exchange caisson formed by a seawall and a breakwater to form a port, a fishing port, etc., and more specifically, the seawater exchange using the flow of seawater that collides with a seawall or a breakwater. The present invention relates to a seawater exchange caisson that effectively purifies the quality of seawater in a port sea area by promoting it.

  In harbor areas where the replacement of seawater is slow, fresh water due to river inflow and precipitation tends to stay and surface water is generated by sunlight, etc., as shown in FIG. 26, which is a sectional view conceptually showing the formation of seawater density stratification. Since the water temperature of the seawater tends to rise, the seawater density of the surface layer tends to decrease. As this progresses, the difference in seawater density between the surface and bottom layers increases and so-called density stratification is formed.

  Due to this density stratification, oxygen supply from the water surface is cut off in the bottom layer, and oxygen is consumed by the decomposition of organic matter and bacteria that inhabit the mud on the seabed, resulting in an anoxic state. In addition, plankton carcasses and zooplankton droppings settle to the bottom layer, where they are decomposed and return to nutrients (mainly nitrogen and phosphorus).

  For this reason, it exists in an anoxic state and a eutrophication state in the bottom layer area. On the contrary, the surface layer region is rich in oxygen and is in a state of little nutrient salt. Due to the stagnation of density stratification, the bottom layer becomes anaerobic, and the bottom mud undergoes reductive decomposition to produce sulfide. In response to such water quality problems in harbor sea areas, there is a need for a technology that efficiently promotes seawater exchange and purifies water quality.

  A conventional seawall and breakwater that promotes seawater exchange will be described below with reference to FIGS. 27 and 28. FIG. 27 is a cross-sectional view showing a conventional seawater purification type revetment and quay wall, in which a water reserving chamber 54 is provided in a dam body 53, and a slit-shaped sea water inlet 55 communicating with the water reserving room 54 is provided as a front wall 56. The lower end 57 of the seawater inlet is positioned near the sea level L, and further, the difference between the sea level of the aquatic chamber 54 and the sea level L in front of the dam body 53 is utilized to enter the water chamber 54. A water guide portion 58 for leading the introduced seawater toward the front of the dam body 53 is provided, and the surface seawater is led to the bottom layer (see Patent Document 1).

  FIG. 28 is a perspective view showing a breakwater having a conventional seawater exchange function, which is a partial cross-sectional view, and an opening 61a that opens over the seawater surface provided on the front wall 61; In the breakwater 73 formed in the levee body 60 in the breakwater body 63, which is connected to the seawater outside the port 71 and the seawater in the port 72 through the opening 62 a provided in the rear wall 62 that opens below the seawater surface, An inclined wall 65 having an inclined surface 65a that rises toward the rear wall 62 is provided in 63 so as to prevent a return flow in the direction of the open sea during a pulling wave (see Patent Document 2).

  Further, the inventors of the present invention have provided a dike having a water intake chamber provided with an introduction port for introducing seawater and a water introduction hole for deriving the introduced seawater. By making the orifice shape smaller than the cross-sectional area on the side, seawater exchange type seawalls and breakwaters that can significantly increase the flow rate of seawater flowing from the reclaimer side to the harbor side than the flow rate from the harbor side to the reclaimer side are provided. It has been proposed (see Patent Document 3).

However, all of the above seawater exchange technologies are so-called one-dimensional seawater exchange technologies that transfer surface seawater to the bottom layer only in the vertical direction, so in the sea area of harbors formed by seawalls and breakwaters. Extensive seawater exchange could not be promoted efficiently, and it was insufficient to solve the water quality problems in the harbor area described above.
JP 2001-159115 A JP-A-9-41341 JP 2004-156306 A

  Therefore, the object of the present invention is to change the water quality in the port inner area by exchanging sea water not only in the vertical direction but also in the horizontal direction between the inner sea side and the outer sea side of the sea area in the port sea area formed by the revetment and the breakwater. It is to provide a seawater exchange type caisson that can improve purification.

  In order to achieve the above object, the means adopted by the seawater exchange type caisson according to claim 1 of the present invention is a revetment that protects the coast from being eroded by the wave force of collision, and extends from the revetment in the offshore direction. In the seawater exchange caisson, which is formed from a breakwater that relaxes in response to incoming waves, the seawall rises due to the impacting wave force, and the flow velocity component parallel to the front wall of the seawall The revetment unit is composed of a plurality of revetment units having a current conversion path for converting into a current having a flow velocity component in a direction away from the front wall surface of the revetment.

  The means adopted by the seawater exchange type caisson according to claim 2 of the present invention is a revetment that protects the coast from being eroded by the impacting wave force, and the incoming waves that extend from the revetment in the offshore direction. In the seawater exchange caisson formed by the breakwater to be relaxed, the breakwater causes the seawater flowing from the outer sea side to the inland sea side to flow in a direction parallel to the inner sea wall of the breakwater and the inland sea of the breakwater. It consists of a plurality of breakwater units provided with a seawater introduction path for converting into a sea current having a flow velocity component in a direction away from the side wall surface.

  The means adopted by the seawater exchange type caisson according to claim 3 of the present invention is a revetment that protects the coast from being eroded by the impacting wave force, and an incoming wave that extends from the revetment in the offshore direction. In the seawater exchange type caisson formed by the breakwater to be relaxed, the seawall moves away from the seawater rising by the wave force that collides with the flow velocity component parallel to the front wall of the seawall and the front wall of the seawall The breakwater is composed of a plurality of revetment units having a current conversion path for converting into a current having a flow velocity component in the direction, and the breakwater is parallel to the inland sea wall of the breakwater. And a plurality of breakwater units having a seawater introduction path for converting into a sea current having a flow velocity component in a direction away from the inner sea side wall of the breakwater.

  The means employed by the seawater exchange type caisson according to claim 4 of the present invention is the seawater exchange type caisson according to any one of claims 1 or 3, wherein the seawall rises by wave power. The rear surface where the seawater collides, the inclined surface that causes the seawater to flow obliquely downward along the front wall of the revetment, and the collision surface that converts the flow direction flowing down this inclined surface to a direction away from the front wall of the revetment The ocean current conversion path is composed of a plurality of revetment units provided along the longitudinal direction of the wall surface of the revetment.

  The means adopted by the seawater exchange caisson according to claim 5 of the present invention is the seawater exchange caisson according to any one of claims 1 or 3, wherein the seawall rises by wave power. , The water receiving part that receives the collided seawater, the drain that allows the seawater received by the water receiving part to flow in one direction along the front wall of the revetment, and the water that flows from the drain There are a plurality of ocean current conversion paths that are provided along the longitudinal direction of the wall surface of the revetment, including a bottom surface that receives seawater and a collision surface that transforms the flow direction of the seawater received on the bottom surface away from the front wall surface of the revetment. It consists of a revetment unit.

  Means employed by the seawater exchange caisson according to claim 6 of the present invention is the seawater exchange caisson according to any one of claims 2 or 3, wherein the breakwater is a seawater on the open sea side, It is composed of a plurality of breakwater units provided with seawater introduction passages that flow into the inland side in a direction that is obliquely downward and has a flow velocity component in a direction along the wall of the breakwater on the inland side. Is.

  The means adopted by the seawater exchange caisson according to claim 7 of the present invention is the seawater exchange caisson according to any one of claims 2 and 3, wherein the breakwater is launched upward from the open sea side. The upper inclined surface that causes the seawater to flow down obliquely downward along the longitudinal direction of the breakwater, and the collision surface that converts the flow direction of the seawater flowing down the upper inclined surface to the inward sea side away from the breakwater The seawater introduction path is composed of a plurality of breakwater units provided along the longitudinal direction of the top surface of the breakwater.

  The means adopted by the seawater exchange type caisson according to claim 8 of the present invention is the seawater exchange type caisson according to claim 7, wherein the breakwater is directed obliquely downward to the sea water on the outer sea side, and It consists of a plurality of breakwater units provided with a seawater introduction path that flows into the inland sea in a direction having a flow velocity component in a direction along the wall surface on the inland sea side of the breakwater.

  According to the seawater exchange type caisson according to claim 1 of the present invention, the revetment that protects the coast from being eroded by the wave force that collides, and the offshore direction extending from this revetment, mitigates the incoming waves In the seawater exchange caisson formed from the breakwater to be driven, the seawall rises due to the impacting wave force, and the flow velocity component parallel to the front wall of the seawall and the direction away from the front wall of the seawall By comprising a plurality of revetment units equipped with ocean current conversion paths that convert into ocean currents having flow velocity components, not only the vertical direction but also the tidal current that flows between the inland sea side and the outside sea side is generated in the sea area near the revetment. In other words, two-dimensional seawater exchange can be performed, so that the water quality in the vicinity of the seawall in the port sea area can be effectively purified and improved.

  Moreover, according to the seawater exchange type caisson of claim 2 of the present invention, the revetment that protects the coast from being eroded by the impacting wave force, and the incoming wave that extends from the revetment in the offshore direction. In the seawater exchange caisson formed by the breakwater to be relaxed, the breakwater causes the seawater flowing from the outer sea side to the inland sea side to flow in a direction parallel to the inner sea wall of the breakwater and the inland sea of the breakwater. In the sea area in the vicinity of the breakwater, not only in the vertical direction, but also on the inland side and the outside sea side As a result, it is possible to generate two-dimensional seawater exchange, so that the water quality in the vicinity of the breakwater in the port sea area can be effectively purified and improved.

  Furthermore, according to the seawater exchange type caisson according to claim 3 of the present invention, the revetment that protects the coast from being eroded by the impacting wave force, and the incoming waves that extend from the revetment in the offshore direction are received. In the seawater exchange type caisson formed by the breakwater to be relaxed, the seawall moves away from the seawater rising by the wave force of collision with the flow velocity component parallel to the front wall of the seawall and the front wall of the seawall The breakwater is composed of a plurality of revetment units having a current conversion path for converting into a current having a flow velocity component in the direction, and the breakwater is parallel to the inland sea wall of the breakwater. And a plurality of breakwater units having seawater introduction paths for converting into ocean currents having a flow velocity component in a direction away from the inner sea wall of the breakwater. Not only the vertical direction but also the tidal current from the inland sea side to the outside sea side can be generated throughout the entire area, so that two-dimensional seawater exchange is possible, so that the water quality in the entire port area can be effectively purified and improved. obtain.

  Furthermore, according to the seawater exchange type caisson according to claims 4 and 5 of the present invention, in the seawater exchange type caisson according to any one of claims 1 or 3, Multiple revetments with specific ocean current conversion paths that convert seawater rising due to force into ocean currents that have a flow velocity component parallel to the front wall of the revetment and a flow velocity component away from the front wall of the revetment Since it consists of units, it is possible to substantially generate a two-dimensional tidal current along the longitudinal direction of the revetment.

  Alternatively, according to the seawater exchange type caisson according to claims 6 and 7 of the present invention, in the seawater exchange type caisson according to any one of claims 2 and 3, the breakwater is connected from the outside sea side to the inside sea. There is a concrete seawater introduction channel that converts seawater flowing into the seawater into a sea current that has a flow velocity component parallel to the inner sea wall of the breakwater and a flow velocity component away from the inner sea wall of the breakwater. Furthermore, since the breakwater unit is composed of a plurality of breakwater units, it is possible to substantially generate a two-dimensional tidal current from the inner sea side to the outer sea side along the longitudinal direction of the breakwater.

  Furthermore, according to the seawater exchange type caisson according to claim 8 of the present invention, the breakwater is constituted by a plurality of breakwater units having two kinds of seawater introduction paths, so that the breakwater extends along the longitudinal direction of the breakwater. Therefore, it is possible to generate a two-dimensional tidal current from the inland sea to the outside sea more reliably.

Hereinafter, a seawater exchange type caisson according to the present invention will be described with reference to FIGS. The caisson in the present invention is a general term for a seawall and a seawall constructed by a seawall unit and a seawall unit.
FIG. 1 is a plan view conceptually showing an embodiment in which the seawater exchange caisson of the present invention is applied to a seawall and a breakwater in a harbor. The code | symbol C shown in FIG. 1 is the seawater exchange type caisson which comprises a harbor, and this seawater exchange type caisson C is the revetment A constructed | assembled by the revetment unit 1 on the coast of the land G, and both ends of this revetment A It is formed from a breakwater B extending in the offshore direction and constructed by a plurality of breakwater units 2.

That is, in FIG. 1, the revetment A forming the seawater exchange type caisson C according to the first embodiment of the present invention uses the flow velocity component in the direction parallel to the front wall surface 3 of the revetment A to the seawater rising by the wave force that collides. 4 and a plurality of revetment units 1 having a sea current conversion path, which will be described later, which is converted into a sea current 6 having a flow velocity component 5 in a direction away from the front wall 3 of the revetment A, and a seawater exchange type caisson C The breakwater B to be formed is a direction in which the seawater flowing from the open sea side S ₁ to the inland sea side S ₂ is separated from the flow velocity component 8 parallel to the inward sea wall 7 of the breakwater B and the inland sea wall 7 of the breakwater. It consists of a plurality of breakwater units 2 provided with a seawater introduction path to be described later.

By configuring as described above, the aggregate of the flow velocity component 4 parallel to the front wall 3 of the revetment A and the aggregate of the flow velocity component 8 parallel to the inner wall 7 of the breakwater B As shown in FIG. 1, a tidal current 11 along the revetment A and a tidal current 12 along the breakwater B are generated on the inland sea side S ₂ , creating a tidal current from the harbor back side to the outside sea side S ₁ as well as the vertical direction. It promotes horizontal seawater exchange and performs effective water purification.

  Next, FIG. 2 is a plan view conceptually showing another example in which the seawater exchange caisson C according to Embodiment 1 of the present invention is applied to a seawall and a breakwater in a harbor. That is, the direction of the ocean current conversion path of some revetment units 1 forming the revetment A and the seawater introduction path of some breakwater units 2 forming the breakwater B are different from those in FIG. The rest of the configuration is exactly the same as that shown in FIG.

In other words, the seawall that has the ocean current conversion path that converts the seawater rising by the wave force that collides into the ocean current 6 having the flow velocity component 4 parallel to the front wall surface 3 and the flow velocity component 5 away from the front wall surface 3. By constructing the revetment A by constructing the unit 1 in the direction in which the flow velocity component 4 in the parallel direction is directed toward the back of the harbor, the aggregate of the flow velocity component 8 in the parallel direction with the wall surface 7 on the inner sea side of the breakwater B Causes a tidal current 11 along the revetment A and a tidal current 12 along the breakwater B to be generated on the inland sea side S _2, and not only in the vertical direction but also in the port counterclockwise from the inland sea side S ₂ to the outside sea side S ₁ . Tidal currents 11 and 12 are created, and horizontal seawater exchange is promoted to effect effective water quality purification.

  1 and 2, the seawater exchange type caisson C according to the first embodiment of the present invention is formed by the seawater exchange type revetment A according to the present invention and the seawater exchange type breakwater B according to the present invention. As described in the case, the seawater exchange type caisson C according to the present invention can be combined such that either the revetment A or the breakwater B is a conventional revetment or breakwater.

For example, although not shown in the figure, when the seawater exchange caisson C is formed of a seawall A composed of a plurality of seawall units 1 according to the present invention and a seawall B composed of a conventional seawall unit, the front wall surface of the seawall A 3, a tidal current 11 along the revetment A is generated on the inland sea side S ₂ , and a tidal current is generated not only in the vertical direction but also on the outside sea side S _1. Accordingly, it is possible to exchange seawater in the horizontal direction.

On the contrary, when the seawater exchange type caisson C is formed by a breakwater A comprising a plurality of conventional breakwater units and a breakwater B comprising a plurality of breakwater units 2 according to the present invention, the front wall surface 7 of the breakwater B and By generating the tidal current 12 along the breakwater B on the inland sea side S ₂ by the assembly of the flow velocity component 8 in the parallel direction, and creating the tidal current toward the outside sea side S ₁ as well as the vertical direction in the inland sea area near the breakwater, Horizontal seawater exchange is also possible.

  In other words, the conventional seawater exchange caisson that combines a seawall and a breakwater is a one-dimensional seawater exchange technology that transports surface seawater to the bottom layer only in the vertical direction. Although the exchange could not be effectively promoted, by combining either the seawall or the breakwater as described above in the form of the seawater exchange caisson according to the present invention, at least the vicinity of either the seawall or the breakwater The inland sea area is effectively purified by horizontal seawater exchange.

  Next, the structure of the seawater exchange caisson C according to Embodiment 1 of the present invention will be described with reference to FIGS. 3 to 6. First, FIG. 3 which is the perspective view which looked at the bank protection unit 1 which forms the said bank protection A of the seawater exchange type caisson C which concerns on Embodiment 1 from the front wall surface 3 side is shown. The revetment unit 1 has a rear surface 20 on which seawater rising by wave force collides with the revetment A, an inclined surface 21 that flows down obliquely along the front wall surface 3, and a flow that flows down the inclined surface 21. By providing an ocean current conversion path 23 including a collision surface 22 that changes the direction away from the front wall surface 3 of the revetment A along the longitudinal direction of the wall surface of the revetment A, as described above, It functions to convert into a sea current 6 having a flow velocity component in a direction parallel to the front wall surface 3 and a flow velocity component in a direction away from the front wall surface 3 of the revetment A.

As a result, a tidal current 11 along the revetment A is generated on the inland sea side S ₂ due to a flow velocity component parallel to the front wall 3 of the revetment A of the sea current 6. The angle θ between the inclined surface 21 of the revetment unit 1 and the horizontal plane is 10 to 30 degrees, and the positional relationship with the sea tide level is such that the intersection point P between the inclined surface 21 and the collision surface 22 is about the average tide level. From the viewpoint of the efficiency of seawater exchange, which is the object of the present invention, it is preferable.

Next, the breakwater unit 2 of the seawater exchange type caisson C according to Embodiment 1 of the present invention that forms the breakwater B is shown in FIGS. Figure 4 is a front view of a part of the breakwater B from the open sea side S _1, FIG. 5 is a plan view seen from above FIG. 4, FIG. 6 is a side view of the FIG. 4 from the right. The breakwater unit 2 forming the breakwater B has a flow velocity in the direction along the wall surface 7 of the inner sea side S ₂ of the breakwater B in the downward direction of the seawater W ₁ on the outer sea side S ₁ due to the water pressure of the incoming waves. A seawater introduction path 26 is provided to flow into the inland sea side S ₂ as the sea current 25 in the direction having components. As a result, a tidal current 12 along the breakwater B is generated by an aggregate of flow velocity components in a direction parallel to the wall surface 7 of the inland sea side S ₂ of the breakwater B of the sea current 25.

In FIG. 4 and FIG. 6, symbol L indicates the sea level, and the height of the breakwater B is set to the level of the sea bottom so that the sea-side S ₁ entrance height of the sea water introduction channel 26 is approximately the same as the sea level L at low tide. It is better to adjust on the basis. Further, the diameter of the seawater introduction path 26 is 500 to 1,000 mm, the angle α between the seawater introduction path 26 and the wall surface 7 of the inland sea side S ₂ of the breakwater B in FIG. 5 is 50 to 70 degrees, and the seawater introduction path in FIG. The angle β formed by 26 with respect to the horizontal plane is preferably 10 to 30 degrees in order to exchange the seawater between the open sea side S ₁ and the inland sea side S ₂ by generating the tidal current 12.

  FIG. 7 is a plan view showing the XX cross section in the perspective view 2 of the seawall-exchangeable caisson C according to the first embodiment for forming the seawall A, and FIGS. It is a top view of the same cross section which shows an embodiment. In the first embodiment, as shown in the plan view of FIG. 7, the collision surface 22 for converting the flow direction of the seawater flowing down the inclined surface 21 of the unit 1 into the ocean current 6 in the direction away from the front wall surface 3 is: Although shown as a configuration perpendicular to the rear surface 20 on the plan view 6, the angle δ formed by the collision surface 22 and the rear surface 20 exceeds 90 degrees as shown in the plan view of FIG. 8, preferably also in the case of FIG. 7. Including 90 to 135 degrees is preferable. If the angle δ is less than 90 degrees, the parallel component of the tidal current 6 is directed in the opposite direction, and if it exceeds 135 degrees, the inclined surface 21 becomes too long and the tidal current 6 is stalled. Further, as shown in the plan view of FIG. 9, the collision surface 22 can be formed in an arc shape having a certain curvature R.

  Next, a second embodiment of the present invention will be described below with reference to FIGS. FIG. 10 is a perspective view showing a seawall-exchangeable caisson C revetment unit according to Embodiment 2 of the present invention that forms the revetment A shown in FIG. Reference numeral 1 denotes a revetment unit that forms the revetment A, and includes a rear surface 20 on which seawater rising due to wave forces collides, a water receiving unit 30 that receives the collided seawater, and seawater received by the water receiving unit 30. A drainage port 31 that flows down in one direction along the front wall 3 of the revetment from the discharge port, a bottom surface 33 that receives seawater flowing down from this drainage port 31, and the flow direction of this seawater that is received at the bottom surface 33 indicates the front wall surface of the revetment A 3 is provided along the longitudinal direction of the wall surface of the revetment A to provide a flow velocity component parallel to the front wall 3 of the revetment A, It functions to convert to sea current 6 having a flow velocity component in a direction away from the front wall surface 3 of the revetment A.

Furthermore, the breakwater unit of the seawater exchange type caisson C according to Embodiment 2 of the present invention that forms the breakwater B shown in FIG. 1 will be described below with reference to FIGS. 11 to 13. Figure 11 is a front view of the breakwater unit 2 from the open sea side S _1, FIG. 12 is a plan view seen from above FIG. 11, FIG. 13 shows a side view of the breakwater B of FIG. 11 from the right side. The breakwater B has an upper inclined surface 40 that causes seawater launched upward from the open sea side to flow obliquely downward along the longitudinal direction of the breakwater B, and a flow direction of seawater flowing down the upper inclined surface 40, a seawater inlet passage 42 made Utsumi side S ₂ direction converted to impact surface 41. away from breakwater B, by providing along the longitudinal direction of the upper surface of the breakwater B, a direction parallel to the front wall surface 7 of the breakwater B And a flow velocity component in a direction away from the wall surface 7 on the inland sea side S ₂ of the breakwater B is converted into the ocean current 6. By the breakwater velocity components of the wall 7 parallel direction Utsumi side S ₂ of the B ocean current 6, by generating power flow 12 along the breakwater B Utsumi side S _2, efficient water exchange with the open sea side S ₁ Make it smooth.

In FIG. 11, the angle γ between the upper inclined surface 40 of the breakwater unit 2 and the horizontal plane is 10 to 30 degrees, and the positional relationship with the seawater tide level is such that the intersection point Q between the inclined surface 40 and the collision surface 41 is as high as the average tide level. It is preferable from the viewpoint of the efficiency of seawater exchange that is the object of the present invention. Although not shown in the figure, the angle on the plan view that the collision surface 41 forms with the wall surface 7 of the inland sea side S ₂ of the breakwater B does not have to be a right angle. The flow velocity component in the direction parallel to the wall surface 7 can be increased.

  FIG. 14 is a plan view showing a YY cross section in a perspective view 10 of the seawall-exchangeable caisson C according to the second embodiment forming the seawall A, and FIGS. 15 and 16 are other views described below. It is a top view of the same cross section which shows an embodiment. In the second embodiment, as shown in FIG. 14, the collision surface 22 that converts the seawater received by the water receiving unit 30 into the ocean current 6 in a direction away from the front wall surface 3 is shown as a configuration perpendicular to the back surface 20. However, as shown in the plan view of FIG. 15, the angle δ formed between the collision surface 22 and the back surface 20 may be an angle exceeding 90 degrees, and δ is 90 for the same reason as described with reference to FIG. It is preferable to set it to -135 degrees. Further, as shown in the plan view of FIG. 16, the collision surface 22 can be formed in an arc shape having a certain curvature R.

Furthermore, FIG. 17 and FIG. 17 of the front view which looked at the breakwater unit 2 of the seawater exchange type caisson C according to another embodiment forming the breakwater B from a part of the breakwater B from the open sea side S ₁ were viewed from above. It is shown in FIG. 19 of the side view seen from the right direction of FIG. 18, FIG. 17 of a top view. As shown in the present embodiment, an upper inclined surface 40 that causes seawater launched from the open sea side S ₁ to the upper portion of the unit 2 to flow obliquely downward along the longitudinal direction of the breakwater B, and the upper inclined surface 40 the flow direction of the sea water flowing down, the seawater inlet passage 42 made Utsumi side S ₂ is converted into the direction impact surface 41. away from breakwater B, provided with the longitudinal direction of the upper surface of the breakwater B, open sea side S ₁ seawater W ₁ is directed obliquely downward, and seawater 25 flows into the inland sea side S ₂ in a direction having a flow velocity component along the wall surface 7 of the breakwater B on the inland sea side S _2. An introduction path 26 can also be provided.

Thus, by providing different types of seawater introduction paths 26 and 42 along the longitudinal direction of the breakwater B, the aggregate of flow velocity components parallel to the wall surface 7 of the inland sea side S ₂ of the breakwater B is obtained. tide 12 along the breakwater B is generated in Utsumi side S _2, it makes it more effectively allow the water exchange with the open sea side S _1.

  As mentioned above, about embodiment of the seawater exchange type caisson according to the present invention, a revetment A constructed by a plurality of revetment units 1 on the coast of land G, and a plurality of breakwaters extending from both ends of the revetment A in the offshore direction. The seawater exchange type caisson C that forms a harbor from the breakwater B constructed by the unit 2 has been described according to the conceptual diagram of FIG. 1, but the breakwater B of FIGS. 11 to 13 described in the second embodiment is implemented. It can also be applied to the first form. Conversely, the breakwater B of FIGS. 4 to 6 described in the first embodiment can be applied to the second embodiment, and the combination of the revetment A and the breakwater B is not particularly limited. Absent.

  As described above, according to the seawater exchange type caisson according to claims 1 to 8 of the present invention, the revetment that protects the coast from being eroded by the impacting wave force, and the incoming wave extending from the revetment in the offshore direction. In the seawater exchange type caisson formed by a breakwater that relaxes by receiving, the revetment is composed of a plurality of revetment units equipped with ocean current conversion paths, or the breakwater is composed of a plurality of breakwater units equipped with seawater introduction paths As a result of the configuration, the aggregate of flow velocity components parallel to the walls of the revetment or breakwater generates a tidal current along the revetment or breakwater on the inner sea side, enabling effective seawater exchange with the outer sea side. .

  Furthermore, in the seawater exchange type caisson formed from a revetment that protects the coast from being eroded by the wave force that collides, and a breakwater that extends from this revetment in the offshore direction and relaxes in response to incoming waves, The revetment is composed of a plurality of revetment units equipped with ocean current conversion paths, and the breakwater is composed of a plurality of breakwater units equipped with seawater introduction paths. It is possible to generate two-dimensional seawater exchange by generating a tidal current, so that the water quality in the port sea area can be effectively purified and improved.

  Next, an embodiment of the revetment that forms the seawater exchange caisson of the present invention will be described with reference to FIGS. FIG. 20 is a plan view showing an embodiment of the present invention, in which water having a depth of 0.3 m is spread on a plane wave-making water tank 45 having a length of 5 m, a width of 5 m, and a depth of 0.5 m. As shown in FIG. 20, the model 46 of the revetment A according to the present invention described with reference to FIG. 20 is arranged at one end of the water tank 45 so as to be parallel to the wave plate 47, and the wave plate 47 generates a uniform wave 48. The effect was confirmed by measuring the flow velocity in the X direction shown in the figure, that is, parallel to the revetment model 46, using the electromagnetic anemometer S indicated by a circle.

  Specific dimensions (mm) of the used revetment model 46 are as shown in 46a of FIG. 21 and 46b of FIG. For comparison, a model having substantially the same external dimensions as described above was also created for the revetment disclosed in Japanese Patent Application Laid-Open No. 2001-159115 described with reference to FIG. 27 as a conventional revetment. The generated wave is a regular wave having a wave height of 7 cm, a period of 1.0 s, and a wavelength of 1.56 m.

  The experimental results are shown in Table 1. The numerical values in the table indicate the maximum value of the X direction flow velocity at the measurement position shown in FIG. In the conventional revetment model shown in FIG. 27 in which a water guide pipe is provided at the lower part of the water reserving room, there is almost no flow in the X direction. You can see that it has occurred.

  Next, an embodiment of a breakwater that forms the seawater exchange caisson of the present invention will be described with reference to FIGS. FIG. 23 is a plan view showing an embodiment of the present invention, in which water having a depth of 0.3 m is applied to the same plane wave-making water tank 45 as described above, and has been described with reference to FIGS. 4 to 6 and FIGS. As shown in FIG. 23, the breakwater model 50 according to the present invention is arranged in a substantially central part of the water tank 45 so as to be parallel to the wavemaking plate 47, and the wavemaking plate 47 generates a uniform wave 48. The effect was confirmed by measuring the flow velocity in the X direction shown in the figure, that is, in the direction parallel to the breakwater model 50, using the electromagnetic current meter S shown.

  Specific dimensions (mm) of the used breakwater model 50 are as shown by 50a in FIG. 24 and 50b in FIG. In the seawater introduction passage 51 of FIG. 24, three through holes having a diameter of 50 mm were opened in each unit so that α = 60 degrees and β = 20 degrees. Further, the angle γ formed by the upper inclined surface in FIG. 25 with the horizontal plane was set to 20 degrees. For comparison, a model having substantially the same external dimensions as described above was created for the breakwater disclosed in Japanese Patent Application Laid-Open No. 9-41341 described with reference to FIG. 28 as a conventional breakwater, and the same experiment was performed. The generated wave is a regular wave having the same wave height of 7 cm, period of 1.0 s, and wavelength of 1.56 m as described above.

  The experimental results are shown in Table 2. The numerical values in the table indicate the maximum value of the X direction flow velocity at the measurement position shown in FIG. In the conventional breakwater model in which an inclined wall is provided in the recreational water chamber, almost no flow in the X direction is generated, but in the breakwater models 50a and 50b of the present invention, a flow of about 60 cm / s is generated.

  From the above results, according to the seawater exchange type caisson according to the present invention, which is formed of a seawall and a breakwater and constitutes a port, a fishing port, etc., not only in the vertical direction of the port sea area but also in the longitudinal direction of the seawall and the breakwater, A tidal current from the inland sea to the outside sea is also generated, so that two-dimensional seawater exchange is possible, so that the water quality in the port sea area can be effectively purified and improved.

It is a top view which shows notionally as embodiment of the seawater exchange type caisson based on this invention which is formed with a seawall and a breakwater, and comprises a harbor. It is a top view shown notionally as other embodiments of the seawater exchange type caisson concerning the present invention which is formed with a seawall and a breakwater and constitutes a harbor. It is a perspective view of the bank protection unit which forms the bank protection of the seawater exchange type caisson concerning Embodiment 1 of the present invention. It is a front view of the breakwater unit which forms the breakwater of the seawater exchange type caisson concerning Embodiment 1 of the present invention. It is a top view of the breakwater unit which forms the breakwater of the seawater exchange type caisson concerning Embodiment 1 of the present invention. It is a side view of the breakwater unit which forms the breakwater of the seawater exchange type caisson concerning Embodiment 1 of the present invention. It is a top view which shows the XX cross section of FIG. It is a top view applicable to the XX cross-section part of FIG. 3 which shows the bank protection unit which forms the bank protection of the seawater exchange type caisson which concerns on other embodiment of this invention. It is a top view applicable to the XX cross-section part of FIG. 3 which shows the bank protection unit which forms the bank protection of the seawater exchange type caisson which concerns on other embodiment of this invention. It is a perspective view of the bank protection unit which forms the bank protection of the seawater exchange type caisson concerning Embodiment 2 of the present invention. It is a front view of the breakwater unit which forms the breakwater of the seawater exchange type caisson concerning Embodiment 2 of the present invention. It is a top view of the breakwater unit which forms the breakwater of the seawater exchange type caisson concerning Embodiment 2 of the present invention. It is a side view of the breakwater unit which forms the breakwater of the seawater exchange type caisson concerning Embodiment 2 of the present invention. It is a top view which shows the YY cross section of FIG. It is a top view applicable to the YY cross section of FIG. 10 which shows the bank protection unit which forms the bank protection of the seawater exchange type caisson which concerns on other embodiment of this invention. It is a top view applicable to the YY cross section of FIG. 10 which shows the bank protection unit which forms the bank protection of the seawater exchange type caisson which concerns on other embodiment of this invention. It is a front view of the breakwater unit which forms the breakwater of the seawater exchange type caisson which concerns on other embodiment of this invention. It is a top view of the breakwater unit which forms the breakwater of the seawater exchange type caisson which concerns on other embodiment of this invention. It is a side view of the breakwater unit which forms the breakwater of the seawater exchange type caisson which concerns on other embodiment of this invention. It is a top view which shows the Example of the bank protection concerning the seawater exchange type caisson of this invention. It is a perspective view which shows the dimension of the revetment model used in the Example of the revetment which concerns on the seawater exchange type caisson of this invention. It is a perspective view which shows the dimension of the other revetment model used in the Example of the revetment which concerns on the seawater exchange type caisson of this invention. It is a top view which shows the Example of the breakwater which concerns on the seawater exchange type caisson of this invention. It is a perspective view which shows the dimension of the breakwater model used in the Example of the breakwater which concerns on the seawater exchange type caisson of this invention. It is a perspective view which shows the dimension of the other breakwater model used in the Example of the breakwater which concerns on the seawater exchange type caisson of this invention. It is sectional drawing which shows notionally formation of the density stratification of seawater. It is sectional drawing which shows the conventional seawater purification type revetment and quay. It is the perspective view which represented the breakwater which has the conventional seawater exchange function, and represented a part with sectional drawing.

Explanation of symbols

A ... Seawall, B ... Breakwater, C ... Seawater exchange caisson, G ... Land
L ... sea level, S ... electromagnetic current meter, S ₁ ... open sea side, S ₂ ... Utsumi side,
W ₁ ... Sea water of the open sea side S ₁ , W ₂ ... Sea water of the inland sea side S ₂ ,
1 ... Revetment unit, 2 ... Breakwater unit, 3 ... Front wall of revetment A,
4 ... direction parallel velocity components and front wall 3 of the ocean currents 6, 5 ... the direction of the velocity components away from the front wall 3 of the ocean currents 6, 6,10 ... ocean currents, 7 ... wall Utsumi side S ₂ of the breakwater B,
8: Flow velocity component parallel to the wall surface 7 of the ocean current 10 9: Flow velocity component away from the wall surface 7 of the ocean current 10
11 ... Tidal current along revetment A, 12 ... Tidal current along breakwater B,
20 ... Back side, 21 ... Inclined surface, 22, 41 ... Collision surface, 23, 32 ... Current flow conversion path,
25 ... sea current, 26,42 ... seawater introduction channel,
30 ... Water receiving part, 31 ... Drain port, 33 ... Bottom surface, 40 ... Upper inclined surface,
45 ... Plane wave tank, 46, 46a, 46b ... Seawall model, 47 ... Wave plate,
48 ... generated wave, 49 ... wave-dissipating material, 50, 50a, 50b ... breakwater model

Claims (8)

  In the seawater exchange caisson formed of a revetment that protects the coast from being eroded by the wave force that collides, and a breakwater that extends offshore from this revetment and relaxes in response to incoming waves, the revetment However, there are a plurality of ocean current conversion paths that convert seawater rising due to the impacting wave force into ocean currents having a flow velocity component parallel to the front wall of the revetment and a flow velocity component away from the front wall of the revetment. A seawater exchange caisson characterized by the seawall unit.   In the seawater exchange caisson formed of a revetment that protects the coast from being eroded by a wave force that collides, and a breakwater that extends offshore from the revetment and relaxes in response to incoming waves, the breakwater However, the introduction of seawater that converts seawater flowing from the open sea side into the inland sea side into a sea current having a flow velocity component parallel to the inner sea wall of the breakwater and a flow velocity component away from the inner sea wall of the breakwater. A seawater exchange caisson comprising a plurality of breakwater units with roads.   In the seawater exchange caisson formed of a revetment that protects the coast from being eroded by the wave force that collides, and a breakwater that extends from the revetment in the offshore direction and relaxes in response to incoming waves, the revetment However, there are a plurality of ocean current conversion paths that convert seawater rising due to the impacting wave force into ocean currents having a flow velocity component parallel to the front wall of the revetment and a flow velocity component away from the front wall of the revetment. The breakwater is composed of a revetment unit, and the breakwater has a flow velocity component parallel to the inner sea wall of the breakwater and a flow velocity component away from the inner wall of the breakwater. A seawater exchange caisson comprising a plurality of breakwater units equipped with a seawater introduction path for converting into a sea current having   The revetment has a rear surface where seawater rising by wave force collides, an inclined surface that causes the seawater to flow obliquely downward along the front wall surface of the revetment, and a flow direction that flows down this inclined surface from the front wall surface of the revetment. The ocean current conversion path composed of a collision surface to be converted in a separating direction is composed of a plurality of revetment units provided along the longitudinal direction of the wall surface of the revetment. Sea water exchange type caisson according to item.   The revetment causes the back surface where seawater rising by wave power collides, a water receiving part that receives the collided seawater, and the seawater received by the water receiving part to flow down in one direction along the front wall of the revetment from the discharge port. An ocean current conversion path comprising a drainage port, a bottom surface for receiving seawater flowing down from the drainage port, and a collision surface for converting the flow direction of the seawater received at the bottom surface away from the front wall surface of the revetment The seawater exchange type caisson according to any one of claims 1 and 3, comprising a plurality of revetment units provided along a longitudinal direction of the seawater.   A plurality of seawater introduction passages, wherein the breakwater is provided with a seawater introduction path for flowing the seawater on the outer sea side into the inland sea side in a direction obliquely downward and having a flow velocity component in a direction along a wall surface on the inner sea side of the breakwater. The seawater exchange caisson according to any one of claims 2 and 3, wherein the seawater exchange caisson is composed of a breakwater unit.   The breakwater has an upper inclined surface that causes seawater launched upward from the open sea side to flow downward obliquely along the longitudinal direction of the breakwater, and the flow direction of seawater that flows down the upper inclined surface is separated from the breakwater. 4. The seawater introduction path comprising a collision surface to be converted in a lateral direction is composed of a plurality of breakwater units provided along the longitudinal direction of the top surface of the breakwater. Seawater exchange caisson according to one of the items. A plurality of seawater introduction passages, wherein the breakwater is provided with a seawater introduction path for flowing the seawater on the outer sea side into the inland sea side in a direction obliquely downward and having a flow velocity component in a direction along a wall surface on the inner sea side of the breakwater. The seawater exchange type caisson according to claim 7, comprising a breakwater unit.

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