JP6750372B2 - Submarine sabo dam - Google Patents

Description

The present invention relates to a seabed erosion control dam.

For example, for the purpose of maintaining the port function to secure the depth and width of the channel, channel dredging work is being carried out to remove the sediment from the seabed of the channel. In particular, in a port located downstream of a river or a port that is easily affected by tidal currents, sediment and mud are likely to accumulate in the channel, and the frequency of dredging work increases, so the cost of maintaining the port function is high. Conventionally, a levee is constructed on both sides of the channel to prevent the channel from being buried by quicksand or mud (for example, Patent Document 1).

JP 2007-16405 A

In the above-mentioned conventional technology, a sand embankment is constructed by stacking concrete blocks and gravel. Since concrete blocks and gravel have a large specific gravity, especially in the case of a muddy harbor where the seabed is covered with floating mud, the submergence of the sand levee will occur on the seabed, preventing sedimentation and mud deposits on the channel. Function may be reduced.

The present invention has been made in view of the above, in which the subsidence to the seabed is small, the deterioration of the function of preventing sedimentation and mud accumulation in the channel is suppressed, and the frequency of channel dredging work is reduced. Providing a seabed erosion control dam.

In order to solve the above-mentioned problems and achieve the object, the seabed erosion control dam of the present invention has a water depth larger than a predetermined depth in a region where the water depth at low tide near the harbor is below a predetermined depth. A submarine sabo dam constructed on the slope between the bottom of the channel where the dredging work was carried out and the existing bottom of the sea so that the top is higher than the bottom of the sea. It is constructed by using coal ash solidified as a raw material and shaped like crushed stone.

As a desirable mode of the present invention, the slope of the slope of the seabed sabo dam on the channel bottom side is larger than the slope of the slope between the seabed bottom and the seabed of the seabed sabo dam.

As a desirable aspect of the present invention, the slope of the slope on the sea bottom side of the seabed sabo dam is larger than the slope of the slope on the seabed bottom side of the seabed sabo dam.

As a preferred aspect of the present invention, the height from the bottom of the channel to the top is different depending on the location where the seabed sabo dam is constructed.

ADVANTAGE OF THE INVENTION According to this invention, the subsidence to the seabed is small, the fall of the function which prevents the accumulation of sediment and mud in a channel is suppressed, and the frequency of the channel dredging construction is provided. You can

FIG. 1 is a diagram showing an example of a route in which a seabed sabo dam is constructed according to an embodiment. FIG. 2 is a diagram showing an example of a harbor in which a seabed sabo dam according to the embodiment is constructed on a shipping route. FIG. 3 is an E-E arrow diagram of the main route shown in FIG. FIG. 4 is a GG arrow view of the sub route shown in FIG. 2.

Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following modes for carrying out the invention (hereinafter referred to as embodiments). The constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the constituent elements disclosed in the following embodiments can be combined appropriately.

FIG. 1 is a diagram showing an example of a route in which a seabed sabo dam is constructed according to an embodiment. In the sea near the port, in a region where the water depth d1 from the sea surface 12 to the sea bottom 11 at low tide is a predetermined depth D (for example, D=13 m) or less (d1≦D), a ship entering the port does not run aground. As described above, in the range of the width W (for example, about 100 m to 300 m), dredging work is performed so that the water depth d2 is larger than the predetermined depth D (d2>D), and the route 13 is provided.

The seabed erosion control dam 10 according to the present embodiment is formed on the slope between the channel bottom surface 11 a below the channel 13 and the existing seabed surface 11 so that the top surface is higher than the existing seabed surface 11.

The slope B of the slope on the channel bottom 11a side of the seabed sand control dam 10 is made larger than the slope A of the slope between the channel bottom 11a and the existing seabed 11. Further, the slope C of the slope on the side of the existing seabed 11 of the seabed sabo dam 10 is made larger than the slope B of the slope on the side of the bottom surface 11a of the seabed sabo dam 10 (A<B<C).

In the example shown in FIG. 1, the slope A between the channel bottom surface 11a and the existing seabed surface 11 is 1:5 or more and 1:3 or less (1:5≦A≦1.3), and the seabed sand control dam 10 The slope B of the slope on the channel bottom 11a side is larger than the slope A of the slope between the channel bottom 11a and the existing seabed 11 and is 1:1 or less (A<B≦1:1), The slope C of the slope on the side of the existing sea bottom 11 of the sea bottom sabo dam 10 is larger than the slope B of the slope on the side of the channel bottom 11a of the sea bottom sabo dam 10, and 1:0.5 or less (B<C≦ 1: 0.5) is shown.

By setting the slope B of the slope on the channel bottom 11a side of the seabed sabo dam 10 to be larger than the slope A of the slope between the channel bottom 11a and the existing seabed 11 (A<B), the seabed sabo dam 10 It is possible to prevent the slope between the channel bottom surface 11a and the existing sea bottom surface 11 from being exposed when the upper part of the vehicle collapses.

Further, by making the slope C of the slope of the seabed sabo dam 10 on the side of the existing seabed 11 larger than the slope B of the slope of the seabed sabo dam 10 on the side of the channel bottom 11a (B<C), the channel bottom 11a It is possible to prevent the floating mud 14 containing the quicksand and the mud from flowing into and accumulating.

In the present embodiment, the seabed erosion control dam 10 uses coal ash generated in a coal-fired power plant or the like as a main raw material, and uses a coal ash solidified product formed into a crushed stone shape (preferably 20 cm or more and 50 cm or less artificial rubble) Created. The solidified material of coal ash, which is mainly made of coal ash, has a smaller specific gravity (range of 2.1 or more and 2.4 or less) than general concrete blocks and gravel, and in particular, the seabed is a sludge-like mud quality. Even in such a case (the specific gravity of alluvial clay is about 2.5 to 2.75), the subsidence of the seabed erosion control dam 10 is small. For this reason, it is possible to suppress deterioration of the function of preventing sedimentation of the sludge 14 including sediment and mud on the bottom surface 11a of the channel, and reduce the frequency of channel dredging work.

In addition, coal ash solidified product using coal ash as a main raw material has an effect of suppressing elution into water by adsorbing hydrogen sulfide that causes malodor and nutrient salts (nitrogen, phosphorus) that cause red tide. Therefore, it is possible to improve the water quality in the sea near the harbor by constructing the seabed sabo dam 10 using the solidified coal ash.

FIG. 2 is a diagram showing an example of a harbor in which a seabed sabo dam according to the embodiment is constructed on a shipping route.

In the example shown in FIG. 2, the main route 13a is connected to an anchorage 16c surrounded by land 15b, 15c, 15d, and the sub route 13b is connected to a coastal anchorage 16a of the land 15a and a coastal anchorage 16b of the land 15b. The sub route 13c is connected to the anchorage 16d on the coast of the land 15d, and is connected to the waterway between the land 15d and the land 15e and the waterway between the land 15e and the land 15f. Submarine erosion control dams 10a, 10b, 10c, 10d, 10e according to the present embodiment are formed on both side slopes of the main route 13a and the sub routes 13b, 13c. Since the end of the submarine sabo dam 10d is connected to the land 15d in the sub route 13c, a submarine sabo dam 10e is formed on one side slope of the sub route 13c in some sections.

Further, in the example shown in FIG. 2, a breakwater 18 is provided in order to prevent the influence of the waves on the anchorages 16a and 16b due to the tidal current F from the offshore. A seabed sabo dam 10a of a main route 13a and a sub route 13b is provided in series with the breakwater 18. FIG. 3 is an E-E arrow diagram of the main route shown in FIG. In the example shown in FIG. 3, the dredging work is performed so that the water depth d2 is larger than the predetermined depth D (d2>D) within the width W1 (for example, about 300 m), and the route 13a is provided. There is.

Also in the example shown in FIG. 3, the slope B1 of the slope on the channel bottom 11a side of the seabed sabo dam 10a is made larger than the slope A1 between the channel bottom 11a and the existing seabed 11. Further, the slope C1 of the slope on the side of the existing sea bottom 11 of the seabed sabo dam 10a is made larger than the slope B1 of the slope on the side of the bottom surface 11a of the seabed sabo dam 10a (A1<B1<C1).

Further, the slope B2 of the slope on the channel bottom 11a side of the seabed erosion control dam 10b is made larger than the slope A2 of the slope between the channel bottom 11a and the existing seabed 11. Moreover, the slope C2 of the slope on the side of the existing sea bottom 11 of the seabed sabo dam 10b is made larger than the slope B2 of the slope on the side of the bottom surface 11a of the seabed sabo dam 10b (A2<B2<C2).

Specifically, in the example shown in FIG. 3, the slope A1 of the slope between the channel bottom 11a and the existing seabed 11 on the side of the seabed sand control dam 10a is 1:5 or more and 1:3 or less (1:5≦ A1≦1.3), the slope B1 of the slope on the channel bottom 11a side of the seabed erosion control dam 10a is larger than the slope A1 between the channel bottom 11a and the existing seabed 11, and 1:1. Below (A1<B1≦1:1), the slope C1 of the slope on the side of the existing sea bottom 11 of the seabed sabo dam 10a is larger than the slope B1 of the slope on the side of the bottom surface 11a of the seabed sabo dam 10a, and An example is shown in which 1:0.5 or less (B1<C1≦1:0.5).

Further, in the example shown in FIG. 3, the slope A2 of the slope between the channel bottom 11a and the existing sea floor 11 on the side of the seabed erosion control dam 10b is 1:5 or more and 1:3 or less (1:5≦A2≦1. .3), the slope B2 of the slope on the channel bottom 11a side of the seabed erosion control dam 10b is larger than the slope A2 between the channel bottom 11a and the existing seabed 11, and 1:1 or less (A2 <B2≦1:1), the slope C2 of the slope of the seabed sabo dam 10b on the existing seabed 11 side is larger than the slope B2 of the slope of the seabed sabo dam 10b on the channel bottom 11a side, and 1:0. An example is set to 0.5 or less (B2<C2≦1:0.5).

By setting the slope B1 of the slope on the channel bottom 11a side of the seabed sabo dam 10a to be larger than the slope A1 between the channel bottom 11a and the existing seabed 11 (A1<B1), the seabed sabo dam 10a It is possible to prevent the slope between the channel bottom surface 11a and the existing sea bottom surface 11 from being exposed when the upper part of the vehicle collapses.

Further, the slope B2 of the slope on the channel bottom 11a side of the seabed sabo dam 10b is made larger than the slope A2 of the slope between the channel bottom 11a and the existing seabed 11 (A2<B2). It is possible to prevent the slope between the channel bottom surface 11a and the existing sea bottom surface 11 from being exposed when the upper part of the dam 10b collapses.

Further, by making the slope C1 of the slope on the side of the existing sea bottom 11 of the submarine sabo dam 10a larger than the slope B1 of the slope on the side of the bottom 11a of the sea bottom sabo dam 10a (B1<C1), the bottom of the route 11a It is possible to enhance the effect of suppressing the flow and accumulation of the floating mud 14 including the quicksand and mud.

In addition, the slope C2 of the slope on the side of the existing sea bottom 11 of the seabed sabo dam 10b is made larger than the slope B2 of the slope on the side of the seabed bottom 11a of the seabed sabo dam 10b (B2<C2). It is possible to enhance the effect of suppressing the flow and accumulation of the floating mud 14 including the quicksand and mud.

Further, in the example shown in FIG. 3, the main passage 13a is easily flowed by the tidal current F from the left side of the drawing, from which the sludge 14 containing sediment and mud easily flows from the seabed erosion control dam 10a side. Therefore, as shown in FIG. 3, the height h1 of the seabed sabo dam 10a from the bottom surface 11a of the seabed is higher than the height h2 of the seabed sabo dam 10b from the bottom surface 11a of the roadway. As a result, it is possible to suppress the inflow of the floating mud 14 including the quicksand and the mud from the seabed erosion control dam 10a side due to the tidal current F from the left side in the figure.

Further, in the example shown in FIG. 2, the river mouth 17 flowing between the land 15f and the land 15g is located at the upper left of the figure, and the water flow from the river mouth 17 flows into the port. FIG. 4 is a GG arrow view of the sub route shown in FIG. 2. In the example shown in FIG. 4, the dredging work is performed so that the water depth d2 is larger than the predetermined depth D (d2>D) within the width W2 (for example, about 100 m), and the route 13c is provided. There is. Further, in the example shown in FIG. 4, an anchorage 16d having a water depth d2 (d2>D) similar to that of the route 13c is provided within a width W3 (for example, about 100 m). Although the example shown in FIG. 4 shows an example in which the water depth of the route bottom 11a and the water depth of the anchorage bottom 11b are equal, the relationship between the water depth of the route bottom 11a and the water depth of the anchorage bottom 11b is limited to this. Not a thing.

Also in the example shown in FIG. 4, the slope B3 of the slope on the channel bottom 11a side of the seabed sabo dam 10e is made larger than the slope A3 between the channel bottom 11a and the existing seabed 11. Further, the slope C3 of the slope on the side of the existing sea bottom 11 of the seabed sabo dam 10e is made larger than the slope B3 of the slope on the side of the bottom surface 11a of the seabed sabo dam 10e (A3<B3<C3).

Specifically, in the example shown in FIG. 4, the slope A3 of the slope between the channel bottom 11a and the existing seabed 11 on the side of the seabed erosion control dam 10e is 1:5 or more and 1:3 or less (1:5≦ A3≦1.3), the slope B3 of the slope on the channel bottom 11a side of the seabed erosion control dam 10e is larger than the slope A3 between the channel bottom 11a and the existing seabed 11, and 1:1. Below (A3<B3≦1:1), the slope C3 of the slope on the existing sea bottom 11 side of the seabed sabo dam 10e is larger than the slope B3 of the slope on the channel bottom 11a side of the seabed sabo dam 10e, and An example is shown where 1:0.5 or less (B3<C3≦1:0.5).

By making the slope B3 of the slope on the channel bottom 11a side of the seabed sabo dam 10e larger than the slope A of the slope between the channel bottom 11a and the existing seabed 11 (A3<B3), the seabed sabo dam 10e. It is possible to prevent the slope between the channel bottom surface 11a and the existing sea bottom surface 11 from being exposed when the upper part of the vehicle collapses.

Further, the slope C3 of the slope on the side of the existing sea bottom 11 of the seabed sabo dam 10e is made larger than the slope B3 of the slope on the side of the seabed bottom 11a of the seabed sabo dam 10e (B3<C3). It is possible to enhance the effect of suppressing the flow and accumulation of the floating mud 14 including the quicksand and mud.

Further, in the example shown in FIG. 4, the sub-passageway 13c is easily flowed by the water flow H from the right side of the drawing, from which the sludge 14 containing sediment and mud easily flows in from the seabed erosion control dam 10e side. Therefore, as shown in FIG. 4, the height h3 of the seabed sabo dam 10e from the channel bottom 11a in the vicinity of the GG arrow is higher than that of the seabed sabo dam 10e (dashed line) in the offshore area in the vicinity of the GG arrow. It is higher than the height h3′ from the bottom surface 11a of the route. As a result, it is possible to suppress the inflow of the floating mud 14 including the quicksand and the mud from the seabed sabo dam 10e side due to the water flow H from the right side in the figure.

As shown in FIGS. 3 and 4, by varying the height from the bottom of the channel 11a to the top surface of the submarine sabo dam 10 depending on the location where the submarine sabo dam 10 is constructed, the water flow across the channel 13 ( It is possible to more effectively suppress the flow of the sludge 14 including the quicksand and the mud due to the (tide).

As described above, the seabed erosion control dams 10, 10a, 10b, 10c, 10d, and 10e according to the embodiment have the predetermined water depth d2 in the region where the water depth d1 at low tide in the sea near the harbor is the predetermined depth D or less. On the slope between the channel bottom 11a of the channel 13 and the existing seabed 11 where the dredging work has been performed so that the water depth d2 is larger than the depth D, the top surface is higher than the existing seabed 11. As such, the specific gravity is smaller than that of a general concrete block or gravel, and the sea bottom erosion control dams 10, 10a, 10b, 10c, 10d, 10e are formed by using a coal ash solidified product formed into a crushed stone shape using coal ash as a main raw material. By creating the submarine erosion control dam 10, 10a, 10b, 10c, 10d, 10e, it is possible to reduce the subsidence to the seabed. As a result, it is possible to suppress the deterioration of the function of preventing the accumulation of the floating mud 14 including sediment and mud on the bottom surface 11a of the channel, and to reduce the frequency of the channel dredging work.

In addition, coal ash solidified product using coal ash as a main raw material has an effect of suppressing elution into water by adsorbing hydrogen sulfide that causes malodor and nutrient salts (nitrogen, phosphorus) that cause red tide. Therefore, the water quality near the harbor can be improved by constructing the seabed sabo dams 10, 10a, 10b, 10c, 10d, and 10e using the solidified coal ash.

Further, the slope B of the slope on the channel bottom 11a side of the seabed sabo dams 10, 10a, 10b, 10c, 10d, 10e is the same as the existing channel bottoms 11a of the seabed sabo dams 10, 10a, 10b, 10c, 10d, 10e. By making it larger than the slope A of the slope with the sea bottom 11, when the upper part of the sea bottom erosion control dam 10, 10a, 10b, 10c, 10d, 10e collapses, the channel bottom 11a and the existing sea bottom 11 It is possible to suppress the exposure of the slope between and.

In addition, the slope C of the slope on the side of the existing sea bottom 11 of the sea bottom sabo dams 10, 10a, 10b, 10c, 10d, and 10e is set to the channel bottom 11a side of the sea bottom sabo dams 10, 10a, 10b, 10c, 10d, and 10e. By making the slope B larger than the slope B, it is possible to enhance the effect of suppressing the sludge 14 including the quicksand and the mud from flowing into and accumulating on the bottom surface 11a of the channel.

Moreover, according to the water flow (tidal current) that crosses the channel 13, the height from the channel bottom 11a to the tops of the seabed erosion control dams 10, 10a, 10b, 10c, 10d, and 10e is made different, so that sediment and mud are removed. It is possible to more effectively suppress the inflow of the floating mud 14 containing the fluid.

10, 10a, 10b, 10c, 10d, 10e Submarine sabo dam 11 Sea bottom 11a Channel bottom 11b Anchorage bottom 12 Sea level 13, 13a, 13b, 13c Channel 14 Floating mud 15a, 15b, 15c, 15d, 15e, 15f, 15g Land 16a, 16b, 16c, 16d Anchorage 17 Estuary

Claims (4)

In the region where the water depth at low tide near the harbor is less than or equal to the specified depth, the method between the bottom of the channel and the existing seabed of the channel where the dredging work has been performed so that the water depth will be larger than the specified depth. A submarine erosion control dam constructed so that the top surface is higher than the sea bottom,
A submarine sabo dam constructed from ash-solidified ash that is made from coal ash as the main raw material. The seabed sabo dam according to claim 1, wherein the slope of the slope of the seabed sabo dam on the side of the bottom of the channel is larger than the slope of the slope between the bottom of the channel and the seabed of the seabed. The seabed sabo dam according to claim 1 or 2, wherein the slope of the slope of the seabed sabo dam on the sea bottom side is larger than the slope of the slope of the seabed sabo dam on the bottom side of the channel. The seabed sabo dam according to any one of claims 1 to 3, wherein a height from the bottom surface to the top surface of the channel differs depending on a location where the seabed sabo dam is formed.

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