JP5669189B2 - Construction method of transmission type sea area control structure - Google Patents

Description

  The present invention relates to a method for constructing a transmission type sea area control structure composed of a transmission type dam body with wave-dissipating performance and a foundation structure that supports the dam body.

  In order to ensure the calmness of the port, it is effective to construct an impermeable breakwater (preventing transmitted waves to the land side) on the offshore side. However, impervious breakwaters are not suitable for preventing beach erosion such as sandy beaches. Whether or not this coastal erosion occurs is mainly determined by the characteristics of sand (specific gravity and shape) and constant wave characteristics. Therefore, it is considered that the influence of erosion due to waves (storms) that strike once every several years to several decades is small in the long term.

  If a breakwater is constructed at a point where coastal erosion is dominant, the reflectance on the front of the breakwater will increase, and the sand off the installation point will be eroded. On the other hand, since sand accumulates on the land side, new measures against erosion on the front surface and accumulation on the back surface are required. In order to prevent coastal erosion, a transmission structure that reduces both the transmission and reflectance around the target point (wave-dissipating performance) is always effective against waves. For example, as shown in FIG. 21, when a transmission structure A is constructed and an incident wave arrives at the transmission structure A from the offshore side, a reflected wave and a transmission wave generated by the incident wave are transmitted in the transmission structure A. By reducing both, it is possible to reduce erosion of the front sand and accumulation of back sand. Since the transmission structure A has a hollow inside and cannot be kept stable by a weight type such as a normal breakwater, the foundation pile B is driven and fixed.

  As the transmissive structure as described above, for example, Patent Document 1 discloses a transmissive sea area control structure and a construction method thereof, and Patent Document 2 discloses a sea area control structure. Each structure has an opening in a member around it and communicates with an internal cavity.

  In the conventional method for constructing a transmission type sea area control structure, after the foundation pile is driven in, the upper levee body is installed using a hoist ship, and the installed dam body and the foundation pile are constructed by connecting mortar grout and the like. There is a method of installing the levee body in several times with an integrated or horizontally divided structure.

An example of the construction procedure of the conventional transmission type sea area control structure will be described.
(1) [Guide tube installation] Transport the guide tube manufactured at the factory to the production yard, and install and fix it at the specified position. (2) [Manufacture of levee body] The dam body is made of reinforced concrete with the guide pipe as a framework. (3) [Steel pipe pile placement] A steel pipe pile with brackets is placed on the sea floor using a vibro hammer. (4) [Installation of the levee body] The dam body is transported by a large hoist ship and installed on the bracket of the steel pipe pile. (5) [Filling mortar] Fill the gap between the steel pipe pile and the guide pipe with mortar grout and fix the dam body.

  Cited document 3 discloses a construction method for an underwater foundation such as caisson, and cited document 4 discloses a construction method for an underwater embankment structure such as caisson.

JP 2007-262890 A JP 2010-59705 A JP-A-2005-330718 JP 58-62210 A

  As shown in FIG. 22, the hoist ship used when installing the upper levee body of the transmission type sea area control structure is large in size because the weight of the dam body A1 constituting the transmission type structure A as shown in FIG. 21 is large. The hoist ship 100 must be used. There is a method of installing multiple vessels without using a large hoisting vessel, but it is disadvantageous in terms of safety, economics, and increase in the area occupied by the sea area.

  However, the large hoist ship 100 has a very high crane height (about 70 to 100 m) and almost no adjustment of the boom height H, so there are places where restrictions on altitude restrictions, electric wires, piers, etc. are near the airport. Construction at a large hoist ship is difficult at the point existing in the area. In addition, when the installation is night work due to the restriction of altitude, the visibility is poor, which is very disadvantageous in terms of safety and installation accuracy.

  The impervious structure such as caisson can adopt the construction method to carry and install in the floating state with the inside of the embankment hollow as in Patent Document 3, in which case a large hoist ship is not required . On the other hand, since the transmission type sea area control structure has an opening penetrating therearound, the construction method cannot be applied.

  It is possible to use a ship with a low crane height by reducing the size of the hoisting ship by dividing the transmission type sea area control structure in advance, but the work period at sea is greatly increased. And it will be very disadvantageous in terms of economy.

  In view of the problems of the prior art as described above, the present invention provides a transmission type sea area control structure composed of a transmission type levee body having an opening in terms of safety and economy without using a large hoisting vessel. It is an object of the present invention to provide a method for constructing a transmission type sea area control structure that can be advantageously constructed.

A construction method of a transmission type sea area control structure for achieving the above object is a transmission type dam body having an opening on each of an upper surface, a bottom surface, a front surface and a rear surface so as to communicate with an internal cavity and having a wave-dissipating performance And a foundation structure comprising a foundation pile that supports the levee body, and a method for constructing a transmissive sea area control structure composed of the pier body , except for the opening on the upper surface of the transmissive dam body Each opening is closed with a water stop plate, and the water stop plate is provided with a communication mechanism capable of communicating inside and outside of the water stop plate, and the water area to be installed in a state where the levee body is lifted by buoyancy The dam body is submerged into water by installing the dam body by opening the communication mechanism and allowing water to flow into the cavity from the outside of the water blocking plate .

According to the construction method of this transmission type sea area control structure, the levee body can be transported to the water area to be installed in a state where the levee body is lifted by buoyancy by closing each opening of the dam body, The levee body can be submerged into the water by flowing water into the cavity in the levee body using the water stop plate communication mechanism at the installation position. In this way, the dam body can be transported and installed in a simple process, so that it is possible to construct a transparent sea area control structure safely and at low cost without the need for a large hoisting ship as in the past. it can. Occlusion of the opening of the upper surface is omitted.

  In the construction method, it is preferable that the foundation pile is placed in advance, water is allowed to flow into the cavity to sink the dam body, and the placed foundation pile is joined to the dam body side.

  In this case, a foundation pile placed in advance and another foundation pile inserted into the bank body can be connected and integrated. Alternatively, a foundation pile that has been cast in advance may be inserted into the dam body, and then concrete may be laid from the upper part of the dam body to obtain the supporting force of the dam body.

  Further, the foundation pile may be driven after the bank body is sunk by discharging air from the cavity.

  In this case, the foundation pile can be temporarily fixed to the bank body and transported, and the foundation pile can be dropped after dropping at the installation position. Alternatively, the foundation pile may be driven after the levee body is installed on the leveling surface with the water bottom leveled.

  In addition, the dam body is kept floating in water by the air in the cavity, and a receiving member for receiving the dam body is attached to the foundation pile in a state where the installed foundation pile is inserted into the dam body. be able to. Since the laid foundation pile is inserted into the dam body, the dam body does not move in the horizontal direction, and the levee body is in a floating state in the water, so that the mounting of the receiving member is not hindered.

Further, the communication mechanism is preferably provided with a valve provided in the waterstop. In this case, the inflow of water and the discharge of air can be controlled by opening and closing the valves constituting the communication mechanism. A pump or the like can be used as the water injection mechanism.

Moreover, the opening part of the said upper surface is not obstruct | occluded among each said opening part . That is, the opening on the upper surface does not necessarily need to be closed, and each opening except the opening on the upper surface is closed .

  According to the construction method of a transmission type sea area control structure of the present invention, a transmission type sea area control structure composed of a transmission type bank body having an opening is constructed in a simple process without using a large hoist ship. It is possible to provide a construction method that is advantageous in terms of safety and economy.

It is a figure which shows an example of the transmission type sea area control structure which can apply the construction method of this embodiment, and is a top view (a), a front view (b), a side view (c), and a rear view (d). It is sectional drawing (b) which cut | disconnected along the II-II line | wire of the bottom view (a) and FIG.1 (b) of the transmission type sea area control structure of FIG. Drawing (a) for explaining the method of levitating and sinking a levee body of a permeation type sea area control structure by this embodiment, a partial enlarged view (b), and the example of composition which attaches a waterstop to a dam body It is a figure (c). It is a block diagram for demonstrating process S01-S07 in the 1st construction method of the penetration type sea area control structure by this embodiment. It is a figure which shows the towing state of a bank body with a 1st construction method. It is a figure which shows the fall state of a foundation pile by a 1st construction method. It is a figure which shows the water injection state to the inside of a dam body by the 1st construction method. It is a figure which shows the placement state of a foundation pile with a 1st construction method. It is a block diagram for demonstrating process S11-S14 in the 2nd construction method of the transmission type sea area control structure by this embodiment. It is a figure which shows the towing state of an installation ground leveling and a bank body with a 2nd construction method. It is a figure which shows the subsidence state of a bank body with a 2nd construction method. It is a figure which shows the placement state of a foundation pile with a 2nd construction method. It is a block diagram for demonstrating process S21-S25 in the 3rd construction method of the transmission type sea area control structure by this embodiment. It is a figure which shows the placement state of a foundation pile and the towing state of a levee body by the 3rd construction method. It is a figure which shows the connection state of a foundation pile by a 3rd construction method. It is a figure which shows the installation state of a bank body by the 3rd construction method. It is a block diagram for demonstrating process S31-S35 in the 4th construction method of the transmission type sea area control structure by this embodiment. It is a figure which shows the placement state of a foundation pile and the towing state of a bank body with a 4th construction method. It is a figure which shows the connection state of a foundation pile by the 4th construction method. It is a figure which shows the installation state of a bank body by the 4th construction method. It is the schematic for demonstrating the reflected wave and transmitted wave which arise by an incident wave when an incident wave arrives at the transmission type structure constructed | assembled in the sea area. It is a side view which shows roughly the large-sized hoist ship used for the installation process of the bank body of the conventional transmission type sea area control structure. It is the bottom view (a), front view (b), and sectional drawing (c) which show another sea area control structure roughly. It is a figure for demonstrating the collection process of a water stop apparatus by the 1st-4th construction method. It is the figure (a) which shows another water stop apparatus which obstruct | occludes the bottom face opening part of a bank body in this embodiment, and its partially expanded view (b).

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a view showing an example of a transmission type sea area control structure to which the construction method of this embodiment can be applied, and is a plan view (a), a front view (b), a side view (c), and a rear view (d). It is. 2 is a bottom view (a) of the transmission type sea area control structure of FIG. 1 and a cross-sectional view (b) taken along line II-II of FIG. 1 (b).

  The transmission type sea area control structure 10 shown in FIGS. 1 and 2 includes a transmission type dam body 11 having a wave-dissipating performance, and a foundation structure 12 including a plurality of foundation piles 29 a and 29 b that support the dam body 11. Is done. The plurality of foundation piles 29a are arranged on the front side (offshore side), and the plurality of foundation piles 29b are arranged on the rear side (land side).

  The dam body 11 has a front vertical wall 13 which is located on the front side (offshore side) and extends in the vertical direction, and a front inclined wall 14 which is inclined from the upper end of the front vertical wall 13, and on the rear side (land side). It has a rear wall 15 which is positioned and extends in the vertical direction, has an intermediate wall 16 parallel to the front vertical wall 13 between the front surface and the rear surface, and side walls 17 and 18 on both side surfaces. Moreover, the bank body 11 has a top plate 19 on the top surface and a bottom plate 20 on the bottom surface.

  The front vertical wall 13 is provided with front vertical wall openings 21 that extend in the horizontal direction and open in the middle of the wall surface, and the front inclined wall 14 extends in the horizontal direction and opens in the middle of the slope. A wall opening 22 is provided. The rear wall 15 is provided with a plurality of rear wall openings 23 on the left and right in the horizontal direction. The intermediate wall 16 is provided with a plurality of intermediate wall openings 24 in the vertical direction. Further, the top plate 19 is provided with an upper surface opening 25, and the bottom plate 20 is provided with a plurality of bottom surface openings 26. Moreover, although the recessed part 18a is formed in the side walls 17 and 18, and the opening part is not provided, you may provide an opening part.

  In addition, in the bank body 11, the preferable opening ratio (ratio of the opening area with respect to a member area) of each opening part is 15 to 40% with the front vertical wall 13 and the front inclined wall 14, 20 to 40% with the rear wall 15, In the horizontal plates of the top plate 19 and the bottom plate 20, the ratio is 10 to 35%.

  As described above, the dam body 11 has the intermediate wall 16 with the intermediate wall opening 24 inside, but the inside is hollow as a whole, the surrounding members, each opening 21 provided inside, 22, 23, 24, 25, and 26 form a permeable structure that allows water to pass therethrough.

  Guide pipes are arranged in the portions of the dam body 11 where the foundation piles 29a and 29b are located so that the foundation piles 29a and 29b are inserted. A foundation structure 12 is constructed by inserting and integrating foundation piles 29 a and 29 b into the guide pipe of the dam body 11, and the dam body 11 is supported by the foundation structure 12.

  The above-described transmission type sea area control structure 10 is a low top end transmission type in which the top end height or the jetty height is about the sea level at the time of high tide and allows the passage of water from the opening. . The main dimensions of the dam body 11 are, for example, a horizontal width parallel to the coastline of 16 m, a height of 8 m, and a depth perpendicular to the coastline of 9.5 m, but these dimensions are examples and can be changed as appropriate. It is. The distance between the bottom plate 20 of the dam body 11 and the water bottom G is preferably about 0 to 2 m. That is, when installing the dam body 11 at intervals with respect to the water bottom G, 2 m or less is preferable.

  According to the transmission type sea area control structure 10 of FIGS. 1 and 2, energy loss due to breaking waves due to overtopping of incident waves from the offshore side (waves going over the upper part of the dam body 11), Energy due to vortices generated in opposite directions due to the outflow water at the front inclined wall opening 22, energy loss due to turbulence due to the inflow water, the intermediate wall opening 24, the rear wall opening 23, and the bottom opening 26. Each energy loss effect such as loss can synergistically promote wave-dissipation and improve the wave-dissipating performance due to energy loss.

  Next, a method for levitating and sinking the above-mentioned bank body 11 will be described with reference to FIG. FIG. 3 is a drawing (a) for explaining a method of levitating and sinking a levee body of a transmission type sea area control structure according to the present embodiment, a partially enlarged view (b) thereof, and attaching a water stop device to the dam body. It is a figure (c) which shows an example of composition.

  As shown in FIG. 3A, the front vertical wall opening 21, the front inclined wall opening 22, the rear wall opening 23 and the bottom opening 26 of the dam body 11 are closed. However, the upper surface opening 25 of the top plate 19 is not closed. That is, for example, as shown in FIG. 3 (b), from a water stop plate 31 covering each opening, and a rubber material for preventing leakage disposed between the water stop plate 31 and the member of the bank body 11. Each opening part 21, 22, 23, 26 is obstruct | occluded using the water stop apparatus 30 provided with the packing 32 which becomes and the opening-and-closing valve 33 provided in the water stop board 31. FIG. The open / close valve 33 constitutes a communication mechanism that enables communication between the inside and the outside of the water stop plate 31. In addition, when the side walls 17 and 18 are provided with openings, they are similarly closed.

  In order to attach the water stop device 30 to the dam body 11, for example, as shown in FIG. 3 (c), embedded anchors AC are provided around the respective openings of the dam body 11, and are stopped using bolts BT. The water stop device 30 is attached by fixing the water plate 31 to the dam body 11 by bolting. In addition, in the case of removal, the bolt BT can be removed by the diver and the water stop device 30 can be removed. Moreover, the attachment means to the bank body 11 of the water stop apparatus 30 is not limited to the structure of FIG.3 (c), You may use another well-known means.

  As shown in FIGS. 3 (a) and 3 (b), the water blocking device 30 including the water blocking plate 31, the packing 32, and the valve 33 closes each opening except the upper surface opening 25 of the dam body 11. Thus, the bank 11 can be floated on the water surface S. In addition, the pump P is installed as a drainage mechanism at the bottom of the dam body 11, and the water in the cavity C of the dam body 11 is discharged by the pump P in a state in which the dam body 11 is submerged into water. It can be lifted back to a '. The pump P can be composed of a submersible pump or the like, and can be used as a drainage mechanism or a water injection mechanism for the cavity C.

  In addition, by opening the valve 33 of the water stop device 30 from the state in which the bank body 11 of FIG. 3 (a) has floated, water flows into the cavity C of the bank body 11 from the valve 33 submerged in water, Air is discharged from the valve 33 and the upper surface opening 25 exiting from S. Thus, by opening the valve 33 as the communication mechanism, the dam body 11 can be submerged in the water from the water surface S in the direction b '. In addition, the pump P may be used to inject water into the cavity C as a water injection mechanism.

  As described above, the floating and sinking of the levee body 11 can be controlled by the outflow / inflow of water to the cavity C in the dam body 11 with the openings except the upper surface opening 25 of the dam body 11 being closed. it can. That is, as shown in FIG. 3A, water is discharged to the cavity C in the levee body 11 in a state where the openings except the upper surface opening 25 of the dam body 11 are closed by the water stop device 30. Moreover, the levee body 11 can be easily levitated and subsidized by being caused to flow.

  Furthermore, by controlling the inflow / discharge amount of water in the cavity C of the levee body 11 by the opening / closing time of the valve 33, the pump P, and the like, the floating state and the subsidence state of the dam body 11 can be appropriately controlled. Thereby, the dam body 11 can be maintained in a state of sinking from the water surface but floating in water.

  The transmission-type dam body 11 has an opening communicating with the cavity C in the dam body 11 in each member due to its structure, and thus it is difficult to float and transport it on the water surface. 3 can be easily levitated and transported by the method shown in FIG. Furthermore, such subsidence can be easily performed when the dam body 11 is sunk to the bottom for installation. For this reason, installation of the dam body 11 can be performed without requiring a large-sized hoist ship as in the prior art, and can be performed safely and at low cost.

  In addition, by closing the bottom opening 26 of the levee body 11, when the levee body 11 is in a floating state, the pump P can be poured into the cavity C, so that a stable state can be easily maintained and towed. It is also possible to pour water inside. Further, the floating / sinking can be adjusted only by the pump P without adjusting the valve 33 of the water stop device 30. This reduces the work of divers.

  Further, in order to maintain the stability of the levee body 11 in a floating state, it is possible to increase the restoring force by pouring water into the cavity C. In this case, a counterweight or the like may be installed at the bottom of the bank body 11. In addition, when towing a place where the water bottom ground is shallow, an auxiliary floating member may be attached to reduce draft.

  Next, first to fourth construction methods for constructing the transmission type sea area control structure 10 of FIGS. 1 and 2 will be described.

<First construction method>
A first construction method of the transmission type sea area control structure according to the present embodiment will be described with reference to FIGS.

  FIG. 4 is a block diagram for explaining steps S01 to S07 in the first construction method of the transmission type sea area control structure according to the present embodiment. FIG. 5 is a diagram showing the towing state of the bank body in the first construction method. FIG. 6 is a diagram illustrating a falling state of the foundation pile by the first construction method. FIG. 7 is a diagram showing a state of water injection into the dam body by the first construction method. FIG. 8 is a diagram showing a foundation pile driving state in the first construction method.

  First, after closing each opening part other than the upper surface opening part 25 of the levee body 11 using the water stop apparatus 30 like Fig.3 (a)-(c), the dam body 11 is suspended and the water surface S is suspended. (S01).

  Next, as shown in FIG. 5, the leveed body 11 that has been levitated is towed by the tow ship F to the water area where the transmission type sea area control structure 10 is constructed (S02). In this case, water is injected slightly into the bottom of the cavity C of the levee body 11 as shown in the figure, and the restoring force is increased to maintain the stability of the dam body 11. The foundation piles 29a and 29b are set in advance on the guide pipe of the dam body 11. That is, as shown in FIG. 5, the foundation piles 29a and 29b are inserted into the guide pipe of the dam body 11 and temporarily held using the stoppers 28a and 28b.

  Next, when the leveed levee body 11 is towed to the installation position of the transmission type sea area control structure 10, the foundation piles 29a and 29 previously set on the guide pipe of the dam body 11 are lowered as shown in FIG. (S03). That is, the foundation piles 29a and 29b are dropped by releasing the stoppers 28a and 28b. Positions G1 and G2 in the bottom G of FIG. 6 are the placement positions of the foundation piles 29a and 29b.

  Next, after dropping the foundation piles 29a and 29b, the stoppers 28a and 28b are mounted again, and the foundation piles 29a and 29b and the dam body 11 are provisionally integrated (S04).

  Next, the valve 33 of the water stop device 30 is opened, air is discharged from the cavity C of the dam body 11, and water is allowed to flow into the cavity C, so that the dam body 11 and the foundation piles 29a and 29b as shown in FIG. And sink to the bottom G (S05). In this case, since the foundation piles 29a and 29b and the bank body 11 are integrated, a downward force is generated in the foundation piles 29a and 29b, and the stability is increased. At this time, the levee body 11 does not reach the bottom G due to underwater floating due to the buoyancy caused by the air remaining in the cavity C.

  Next, the stoppers 28a and 28b are released, and the foundation piles 29a and 29b are driven to the bottom G by the pile driving boat D and driven to a predetermined depth as shown in FIG. 8 (S06).

  Next, the temporary support bracket 27 is attached to the lower side of the bottom plate 20 of the dam body 11 on the foundation piles 29a and 29b (S07). The temporary receiving bracket 27 can be installed on the foundation piles 29a and 29b using a known band or the like. The bottom plate 20 of the dam body 11 is received by the temporary receiving bracket 27, and the dam body 11 can maintain a predetermined gap between the bottom plate 20 and the water bottom G, and the installation of the dam body 11 is completed. In addition, when air remains in the cavity C in the bank 11, water is appropriately introduced through the valve 33.

  Then, the construction at the predetermined installation position of the transmission type sea area control structure 10 is completed by removing the water stop device 30.

<Second construction method>
A second construction method of the transmission type sea area control structure according to the present embodiment will be described with reference to FIGS.

  FIG. 9 is a block diagram for explaining steps S11 to S14 in the second construction method of the transmission type sea area control structure according to the present embodiment. FIG. 10 is a diagram showing the ground leveling and the towing state of the levee body by the second construction method. FIG. 11 is a diagram illustrating a subsidence state of the bank body by the second construction method. FIG. 12 is a diagram showing a foundation pile driving state by the second construction method.

  First, as shown in FIG. 10, if the ground of the bottom G where the transmission type sea area control structure is installed is in a non-land state, the leveling surface Ga is formed in advance (S11). At this time, a stone is placed on the leveling surface Ga where the levee body 11 is placed, and a mountain portion Gb protruding from the leveling surface Ga is formed.

  Next, after closing each opening part other than the upper surface opening part 25 of the bank body 11 using the water stop apparatus 30 like Fig.3 (a)-(c), the bank body 11 is hung down and water surface As shown in FIG. 10, the levee body 11 is towed by the tow ship F to the water area where the permeable sea area control structure 10 is constructed as shown in FIG. 10 (S12). In this case, water is injected slightly into the bottom of the cavity C of the levee body 11 as shown in the figure, and the restoring force is increased to maintain the stability of the dam body 11.

  Next, after the levitated levee body 11 is towed to the installation position of the transmission type sea area control structure 10, the valve 33 of the water stop device 30 is opened as shown in FIG. Is discharged and water is allowed to flow into the cavity C, so that the levee body 11 is sunk into the mountain portion Gb on the leveling surface Ga of the water bottom G while adjusting the position of the dam body 11 (S13).

  Next, when the installation of the dam body 11 is completed, the foundation piles 29a and 29b are driven to the bottom G by the pile driving boat D and driven to a predetermined depth as shown in FIG. 12 (S14). Thereby, installation of the bank 11 is completed.

  Then, the construction at the predetermined installation position of the transmission type sea area control structure 10 is completed by removing the water stop device 30.

<Third construction method>
A third construction method of the transmission type sea area control structure according to the present embodiment will be described with reference to FIGS.

  FIG. 13 is a block diagram for explaining steps S21 to S25 in the third construction method of the transmission type sea area control structure according to the present embodiment. FIG. 14 is a diagram showing the foundation pile driving and the towing state of the dam body by the third construction method. FIG. 15 is a diagram showing a connection state of foundation piles by the third construction method. FIG. 16 is a diagram showing the installation state of the bank body by the third construction method.

  First, as shown in FIG. 14, foundation piles 29c and 29d are previously driven by a pile driving ship to the bottom G of the installation position of the transmission type sea area control structure 10 and driven to a predetermined depth (S21). In this case, it is preferable that the foundation piles 29c and 29d are driven to a height that does not hinder the towing of the dam body 11 in the next process.

  Next, after closing each opening part other than the upper surface opening part 25 of the bank body 11 using the water stop apparatus 30 like Fig.3 (a)-(c), the bank body 11 is hung down and water surface As shown in FIG. 14, the levee body 11 is towed by the tow ship F to the water area where the permeable sea area control structure 10 is constructed as shown in FIG. 14 (S22). In this case, water is injected slightly into the bottom of the cavity C of the levee body 11 as shown in the figure, and the restoring force is increased to maintain the stability of the dam body 11. The foundation piles 29a and 29b are set in advance on the guide pipe of the dam body 11. That is, as shown in FIG. 14, the foundation piles 29a and 29b are inserted into the guide pipe of the dam body 11 and temporarily held using the stoppers 28a and 28b.

  Next, as shown in FIG. 15, with the dam body 11 positioned at a predetermined position, the foundation piles 29a and 29b are lowered by releasing the stoppers 28a and 28b, and the foundation piles 29c and 29b previously placed are placed. In the meantime, the foundation piles 29a and 29c and the foundation piles 29b and 29d are connected and integrated by a known connecting means such as underwater welding at a connecting portion 29e (shown by hatching in FIG. 15) (S23). At this time, the dam body 11 floats and is in a floating state in water.

  Next, as shown in FIG. 16, the temporary support bracket 27 is attached to the foundation pile 29a or 29c, 29b or 29d at a predetermined position below the bottom slab 20 of the dam body 11 (S24). The temporary bracket 27 can be installed on the foundation pile using a known band or the like.

  Next, as shown in FIG. 16, the valve 33 of the water stop device 30 is opened, air is discharged from the cavity C of the bank body 11, and water is allowed to flow into the cavity C, so that the bank body 11 sinks and the bottom plate 20 The dam body 11 is received by the temporary receiving bracket 27, and the dam body 11 can maintain a predetermined gap between the bottom plate 20 and the water bottom G, and the installation of the dam body 11 is completed (S25).

  Then, the construction at the predetermined installation position of the transmission type sea area control structure 10 is completed by removing the water stop device 30.

<Fourth construction method>
A fourth construction method of the transmission type sea area control structure according to the present embodiment will be described with reference to FIGS.

  FIG. 17 is a block diagram for explaining steps S31 to S35 in the fourth construction method of the transmission type sea area control structure according to the present embodiment. FIG. 18 is a diagram showing the foundation pile driving and the towing state of the dam body by the fourth construction method. FIG. 19 is a diagram showing a connection state of foundation piles by the fourth construction method. FIG. 20 is a diagram showing an installation state of the bank body by the fourth construction method.

  First, as shown in FIG. 18, foundation piles 29a and 29b are driven in advance by a pile driving ship to the bottom G of the installation position of the transmission type sea area control structure 10 and driven to a predetermined depth (S31). In this case, it is preferable that the foundation piles 29a and 29b are driven to a height that does not hinder the towing of the dam body 11 in the next process.

  Next, as shown in FIG. 18, the temporary receiving brackets 27 are respectively attached to the foundation piles 29a and 29b (S32). The temporary bracket 27 can be installed on the foundation pile using a known band or the like.

  Next, after closing each opening part other than the upper surface opening part 25 of the bank body 11 using the water stop apparatus 30 like Fig.3 (a)-(c), the bank body 11 is hung down and water surface As shown in FIG. 18, the levee body 11 is towed by the tow ship F to the water area where the permeable sea area control structure 10 is constructed as shown in FIG. 18 (S33). In this case, water is injected slightly into the bottom of the cavity C of the levee body 11 as shown in the figure, and the restoring force is increased to maintain the stability of the dam body 11.

  Next, with the bank body 11 positioned at a predetermined position, as shown in FIG. 19, the valve 33 of the water stop device 30 is opened, air is discharged from the cavity C of the bank body 11, and water is allowed to flow into the cavity C. Then, the levee body 11 and the foundation piles 29a and 29b are joined by sinking the levee body 11 and inserting the foundation piles 29a and 29b that are placed in the guide pipe of the dam body 11. Further, by sinking the levee body 11, the bottom plate 20 is received by the temporary receiving bracket 27, and the dam body 11 is installed (S34). Thereby, the bank 11 can maintain a predetermined gap between the bottom plate 20 and the water bottom G.

  Next, as shown in FIG. 20, concrete or mortar is cast from the upper part of the dam body 11 into the guide pipe and filled to the pile heads of the foundation piles 29a and 29b, and the foundation pile filling parts 29f and 29g (hatching in FIG. 20). The supporting force of the levee body 11 is secured together with the lower foundation piles 29a and 29b (S35).

  Then, the construction at the predetermined installation position of the transmission type sea area control structure 10 is completed by removing the water stop device 30.

  As described above, according to the first to fourth construction methods of the present embodiment, the dam body 11 is lifted by buoyancy by closing each opening except for the upper surface opening 25, and While being able to transport to a water area, water can be made to flow in from the valve | bulb 33 to the cavity in the bank body 11 in an installation position, and the bank body 11 can be sunk in water. Since the dam body 11 can be installed in a simple process as described above, the transmission type sea area control structure 10 can be constructed safely and at low cost without requiring a large-sized hoisting ship as in the prior art. it can.

  Note that, when the dam body 11 is submerged in the water, the water is poured into the cavity of the dam body through the valve 33 of the water stop device 30, but water may be poured using the pump P. Alternatively, water may be injected using the valve 33 and the pump P together.

  Moreover, the recovery of the water stop device 30 in the first to fourth construction methods can be performed by connecting the water stop device 30 to the tip of the wire W and winding up using the winch V as shown in FIG. .

  Moreover, after installing a bank body in the 1st-3rd construction method, filling the mortar grout into the clearance gap between the guide pipe of the bank body 11 and a foundation pile, and aiming at integration with a bank body and a foundation pile. preferable. In addition, when the temporary support bracket 27 is attached, the temporary support bracket 27 may be removed, but may be left, and when left, it can be attached to the foundation pile by underwater welding or the like.

  Next, another water stop device for closing the bottom opening 26 of the bottom plate 20 will be described with reference to FIG. As shown in FIGS. 25 (a) and 25 (b), the water stop device 40 includes a water stop plate 41 made of a steel plate formed so as to cover the entire bottom plate 20 of the dam body 11, a rubber material arranged thereon, and the like. And a plurality of bottom openings 26 can be collectively closed. At both ends of the water stop device 40, a plurality of holes 42a are formed so that the plurality of foundation piles 29a, 29b pass therethrough. The water stop device 40 can be attached by bolting the embedded anchor of the dam body 11 at a plurality of locations in the same manner as in FIG.

  25, the plurality of bottom openings 26 of the dam body 11 are closed with the water stop device 40 described above, and the installation process of the dam body 11 is performed. After the installation is completed, the water stop device 40 is removed and left without being collected. As shown in (a), by sinking to the bottom G and covering the bottom G, it is possible to prevent scouring around the foundation piles 29a and 29b in the transmission type sea area control structure 10 after construction. The water stop device 40 shown in FIGS. 25A and 25B can be applied as appropriate in the first to fourth construction methods described above.

  As described above, the modes for carrying out the present invention have been described. However, the present invention is not limited to these, and various modifications can be made within the scope of the technical idea of the present invention. For example, the transmission type sea area control structure to which the construction method of the present invention can be applied is not limited to the structure shown in FIGS. 1 and 2, but may be other structures. For example, the present invention can be applied to a sea area control structure as shown in FIGS.

  That is, in the sea area control structures of FIGS. 23A to 23C, a box-shaped block 91 whose inside is hollowed out is fixed to the bottom of the water by a plurality of piles 90. A front side wall 92 having an opening 93 (offshore side), a rear side wall 94 having a plurality of openings 95 (land side), an intermediate wall 96 having a plurality of intermediate wall openings 97, and The bottom plate 98 has a plurality of openings 99, and the top plate has a plurality of openings similar to the openings 99. The rear wall 94 is provided with a protruding portion 94a on the upper surface side so as to protrude from the average sea level. The sea area control structure shown in FIGS. 23 (a) to 23 (c) closes each opening in the same manner as in the above-described embodiment, and lifts, conveys, and sinks without closing the opening of the top plate. Can be installed at. In addition, although the opening part is not provided in the both sides | surfaces of the box-shaped block 91, you may provide, and when it provides an opening part, it will block | close similarly.

  Moreover, in this embodiment, although the upper surface opening part 25 of the upper surface of the dam body 11 was not obstruct | occluded, you may obstruct | occlude with the water stop apparatus 30 grade | etc., Like other opening parts.

  In addition, the valve 33 of the water stop device 30 in the dam body 11 in FIG. 3A is arranged on the inner side (the cavity C side) in the bottom plate 20 and arranged outside on the other side, but is not limited to this. It may be arranged on the opposite side. When the valve 33 is arranged on the cavity C side, the valve 33 can be opened and closed in the cavity C.

  Moreover, although the dam body 11 of FIG. 1 is the structure which has the front vertical wall 13 and the front inclined wall 14 in the front side (offshore side), you may comprise the whole front surface in a vertical wall, and the whole front surface. May be configured as an inclined wall.

  According to the construction method of the transmission type sea area control structure of the present invention, the transmission type sea area control structure can be constructed by a simple process without using a large hoisting ship, which is advantageous in terms of safety and economy. Since the construction method can be provided, the transmission type that can reduce the erosion of sand on the front side (offshore side) and the accumulation of sand on the back side (land side) by reducing both reflected waves and transmitted waves caused by incident waves in the sea area A sea area control structure can be constructed at low cost and safely.

DESCRIPTION OF SYMBOLS 10 Transmission type sea area control structure 11 Deck body 12 Foundation structure 13 Front vertical wall 14 Front inclined wall 15 Rear wall 16 Rear wall 16 Intermediate wall 17, 18 Side wall 19 Top plate 20 Bottom plate 21 Front vertical wall opening 22 Front inclined wall opening 23 Rear wall opening 24 Middle wall opening 25 Upper surface opening 26 Bottom surface opening 27 Temporary receiving brackets 28a, 28b Stoppers 29a, 29b Foundation pile 30 Water stop device 31 Water stop plate 32 Packing 33 Open / close valve, valve (communication mechanism)
G Water bottom Ga Leveling surface Gb Mountain P Pump (water injection mechanism, drainage mechanism)

Claims (6)

Consists of a transmission type levee body having an opening on the top surface, bottom surface, front surface and rear surface so as to communicate with the internal cavity, and a foundation structure including a foundation pile supporting the dam body A method for constructing a transmitted sea area control structure,
Wherein each of said openings, except for the opening of the upper surface of the transmission type embankment closed by waterstop, wherein the waterstop is communicable communication mechanism is mounted inside and outside of the waterstop ,
Carrying the levee body up to the target water area in a state where it is levitated by buoyancy,
A transmission type sea area control structure characterized in that the communication mechanism is opened and water is allowed to flow into the cavity from the outside of the water blocking plate so that the bank body is submerged into the water and the bank body is installed. Construction method.   The permeation type sea area control structure according to claim 1, wherein the foundation pile is placed in advance, the levee body is sunk by flowing water into the cavity, and the placed foundation pile is joined to the dam body side. How to build things.   The construction method of a transmission type sea area control structure according to claim 1, wherein the foundation pile is driven after the dam body is sunk.   The dam body is kept in an underwater floating state by air in the cavity, and a receiving member for receiving the dam body is attached to the foundation pile in a state where the placed foundation pile is inserted into the dam body. The construction method of the transmissive | pervious sea area control structure of any one of 1-3. The communication mechanism, method of constructing of claims 1 to translucent waters control structure according to any one of 4 comprises a valve provided in the waterstop. The uplift / sink of the levee body is controlled by controlling inflow of water into the cavity by the communication mechanism and / or water injection mechanism and drainage from the cavity by a drainage mechanism . The construction method of the transmission-type sea area control structure of any one of Claims 1.

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