JP6286193B2 - Revetment structure - Google Patents

Description

  The present invention relates to a revetment structure built in a harbor or the like.

  A revetment structure using a steel plate cell is adopted when building a revetment for cargo handling by bringing cargo ships and the like together. As illustrated in FIG. 7, the revetment structure 1X includes a plurality of steel plate cells 2X arranged side by side at intervals, a steel plate arc 3X that connects between adjacent steel plate cells 2X, and a plurality of steel plate cells. 1X and the upper surface body 4X formed in the upper surface of the steel plate arc 3X.

  In order to build this revetment structure 1X, first, a cylindrical steel plate cell 2X made of steel plates is placed on the seabed near the coastline. At this time, vibration is applied to the steel plate cell 2X from the upper end side by a vibrator called a vibro hammer. By this vibration, the lower end side of the steel plate cell 2X is driven into the seabed ground.

  Thereafter, the filling material 5 such as stone or sand is introduced into the steel plate cell 2X. After the installation of the plurality of steel plate cells 2X is completed, a curved plate-shaped steel plate arc 3X is placed on the seabed ground so as to fill between the adjacent steel plate cells 2X. Thereafter, the steel plate arc 3X is welded to the steel plate cell 2X, and the filling material 5 is introduced into the inside thereof.

  Concrete is placed so as to cover the upper surface of the steel plate cell 2X and the steel plate arc 3X in which the filling material 5 is charged. As the concrete solidifies, an upper surface body 4X is formed on the upper surfaces of the steel plate cell 2X and the steel plate arc 3X. The wall-shaped revetment structure 1X is constructed through the above steps. After the revetment structure 1X is constructed, for example, the land side L of the revetment structure 1X is reclaimed and used as a harbor structure. Here, S in the figure indicates the offshore side (the side on which the waves come).

  Since this revetment structure 1X can manufacture the steel plate cell 2X and the steel plate arc 3X in a factory etc., there exists an advantage that a construction period can be shortened.

  However, the revetment structure 1X may adversely affect a ship that navigates in the vicinity of the revetment structure 1X. This is because the ship is affected by the reflected wave of the wake wave and the wind wave that collided with the revetment structure 1X. For this reason, there is a problem in that the navigating and berthing operations of the ship are adversely affected.

  On the other hand, although different from the revetment structure, a structure of a transmission type breakwater using a steel plate cell has been proposed (see, for example, Patent Document 1). A plan view of the transmission breakwater 30Y is shown on the upper side of FIG. 8, and a perspective view of the breakwater 30Y is shown on the lower side of FIG. Since this wave breakwater 30Y is a transmission type, it does not have a steel plate arc. Further, the upper surface body 4Y of the steel plate cell 2Y is made of concrete placed in a staircase shape, and has reflecting surfaces 31 and 32 having different depths. The arrow F in the figure indicates the direction of wave flow.

The wave breakwater 30Y has a function of generating reflected waves having different phase differences on the different reflecting surfaces 31 and 32 in the stepped upper surface body 4Y and canceling the reflected waves to each other (hereinafter referred to as a first function). ing. At this time, the positions of the reflection surfaces 31 and 32 determine the wavelength of the wave to be quenched based on the average wavelength of the incoming waves, etc., and the phase difference between the reflection waves generated on the reflection surfaces 31 and 32 is , And are configured to have an opposite phase (180 degree delay). In addition, the breakwater 30Y
It is said that it has an action of consuming wave energy (hereinafter referred to as a second action) due to the breaking of waves when the waves get over the step. Further, as shown in the upper side of FIG. 8, the breakwater 30Y has an action (hereinafter referred to as a third action) that cancels incident waves that have flowed into the upper surface body 4Y by colliding with each other. Therefore, in order to improve the wave-dissipating performance, it can be considered that the upper surface body 4X of the revetment structure 1X shown in FIG.

  However, even if the above-described stepped upper surface body 4Y is employed for the revetment structure 1X, sufficient wave-dissipating performance cannot be obtained. First, there is a problem that the wave-absorbing effect due to the first action cannot be obtained. This is different from the offshore where waves of a certain wavelength arrive throughout the year, which is assumed as the construction site of the breakwater 30Y, and the wake waves and wind waves that arrive at the revetment structure 1X have a wide variety of wavelengths. This is because the wavelength of the wave to be quenched by the upper surface body 4Y is not fixed to one. Specifically, the wavelength of wake waves varies greatly depending on the size of the ship. Also, the wavelength of wind waves varies greatly depending on weather conditions. In particular, the vicinity of the coastline where the revetment structure is constructed is also affected by the surrounding topography and the like, so the wavelength of the wind wave is rich in diversity. Therefore, the stepped upper surface body 4Y cannot obtain a sufficient wave-dissipating effect.

  Secondly, the stepped upper surface body 4Y has a problem that once the shape is determined and applied, the shape cannot be easily changed. As described above, it is difficult to determine the wavelength of the wave to be wave-dissipated, and even if the stepped upper surface body 4Y is manufactured in a preset shape, a sufficient wave-dissipating effect may not actually be obtained. is there. In particular, the reflected wave may be amplified depending on the wavelength of the incoming wave.

  Third, there is a problem that the wave-absorbing effect by the third action cannot be obtained. This is because in the revetment structure 1X in which it is an essential condition that the steel plate arc 3X is installed and the wave is not transmitted, there is no flow that causes the incident waves F to collide with each other as shown in the upper side of FIG.

JP 2001-20247 A

  The present invention has been made in view of the above problems, and its purpose is to provide a highly versatile revetment structure that can obtain a sufficient wave-dissipating effect even under environmental conditions in which the wavelength of the wave changes. It is to be.

In order to achieve the above object, the revetment structure according to the present invention is driven into a seabed connecting a plurality of steel plates placed side by side at a distance and between adjacent steel plate cells. Steel plate arc, and a plurality of steel plate cells and an upper surface body formed on the upper surface of the steel plate arc, in the revetment structure, the upper surface body is made of concrete, and the lower surface of the steel plate cell and the steel plate cell in a horizontal state. A protrusion that is disposed over the upper surface of the steel sheet arc, protrudes from the upper surface of the upper surface body and extends in the horizontal direction of the steel sheet cell, and on the upper surface of the upper surface body, on the offshore side of the protrusion. A plurality of wave-dissipating blocks arranged, and the upper surface of the block complex composed of the plurality of wave-dissipating blocks is inclined upward from the offshore side toward the land side. When waves collide Characterized in that it is set to monitor overtopping non heights.

With the configuration of the present invention, the block composite mainly exhibits a wave-dissipating effect, but by adjusting the number and arrangement of the wave-dissipating blocks, a sufficient wave-dissipating effect can be obtained for various environmental conditions. it can. In addition, since various adjustments of the wave-dissipating block can be performed flexibly according to environmental conditions, the versatility is extremely high.

  In addition, since the upper surface of the block complex is inclined upward from the offshore side to the land side, it is easy to capture the incoming wave into the block complex without reflecting it, and the energy of the wave within the block complex. It is advantageous to attenuate.

  Furthermore, it can be expected that the wave moving upward along the depression extending in the vertical direction of the arcuate wall of the steel plate cell and the steel plate arc is taken into the block composite and attenuated. That is, it is possible to expect a wave-dissipating effect due to cooperation between the arc-shaped wall and the block composite.

  In the above revetment structure, for example, the upper surface of the upper body is set at a position lower than the average water level. Preferably, the upper surface of the upper surface body is set at a position lower than the low tide water level. With this configuration, the revetment structure can obtain a sufficient wave-dissipating effect regardless of the tides.

  In the above revetment structure, the block composite may be arranged on an inclined surface inclined upward from the offshore side to the land side of the inclined body formed on the upper surface of the upper surface body. it can. With this configuration, the air gap inside the block composite and the wave (seawater) can be replaced smoothly, and an improvement in the wave-dissipating effect can be expected. In addition, the number of wave-dissipating blocks to be used can be suppressed.

  In the above revetment structure, the length from the offshore side end to the land side end of the block complex is set to, for example, 7 m to 12 m. In order to secure a sufficient wave-dissipating effect stably, the length of the block complex should be set within this range.

It is sectional drawing which showed the outline of embodiment of the revetment structure of this invention. It is the top view which showed the outline of embodiment of the revetment structure of this invention. It is explanatory drawing of the plane which illustrates the behavior of the wave which arrives at the revetment structure of this invention. It is explanatory drawing of the cross section which illustrates the behavior of the wave which arrives at the revetment structure of this invention. It is sectional drawing which showed the outline of another embodiment of the revetment structure of this invention. It is the schematic of the modification of a steel plate cell. It is the schematic which illustrates the conventional revetment structure. It is the schematic which illustrates the conventional breakwater.

  Hereinafter, the revetment structure of the present invention will be described with reference to the embodiments shown in the drawings. The revetment structure 1 of the embodiment illustrated in FIG. 1 and FIG. 2 is a steel plate arc (offshore side steel plate arc) that connects between a plurality of steel plate cells 2 that are installed side by side at intervals and adjacent steel plate cells 2. 3S and land-side steel plate arc 3L) and a plurality of steel plate cells 2 and top surface bodies 4 formed on the top surfaces of steel plate arcs 3S and 3L. Further, the revetment structure 1 protrudes from the upper surface of the upper surface body 4 and extends in the side-by-side direction (vertical direction in FIG. 2) of the steel plate cells 2, and the protrusion 11 on the upper surface of the upper surface body 4. And a plurality of wave-dissipating blocks 12 arranged on the offshore side S of the vehicle. The upper surface of the block composite 13 composed of the plurality of wave-dissipating blocks 12 is inclined upward from the offshore side S toward the land side L. Is set. The ratio of the gaps between the wave-dissipating blocks 12 with respect to the outer volume of the block composite 13, that is, the porosity in the block composite 13 is, for example, 45% to 70%. A support member 15 extends along the protruding body 11 on the land side L from the protruding body 11 on the upper surface of the upper surface body 4.

The lower end portions of the steel plate cell 2 and the steel plate arcs 3S, 3L are embedded in the seabed ground 7, and a solid structure 8 is constructed on the seabed ground 7 in the offshore side S and the land side L. The inside of the cylindrical steel plate cell 2 is filled with a filling material 5. Embedded land 9 is thrown into the land side L of the revetment structure 1. The support member 15 prevents the protruding body 11 and the wave-dissipating block 12 from moving toward the land side L.

  It is desirable that the upper surface of the upper surface body 4 is set at a position lower than the average water level WL. Furthermore, it is more desirable that the upper surface of the upper surface body 4 is set at a position lower than the envy average low tide level LWL (Low Water Level). HWL in FIG. 1 indicates the envy average high tide level (High Water Level). The average water level WL is an average value of the envy average low tide level LWL and the envy average high tide level HWL.

  As shown in FIG. 1, the projecting body 11 has a substantially L-shaped cross section having a vertical portion and a horizontal portion protruding from the lower end portion of the vertical portion to the offshore side S. The outer shape of the block complex 13 is indicated by a broken line.

  Next, the construction method of the revetment structure 1 is demonstrated. As in the conventional case, first, a cylindrical steel plate cell 2 made of a steel plate is driven into the seabed ground 7. The steel plate cell 2 driven into the seabed ground 7 is firmly supported by the root structure 8. Thereafter, the filling material 5 is introduced into the steel plate cell 2. Through the above steps, the plurality of steel plate cells 2 are fixed to the seabed ground 7 (steel plate cell installation step).

  After the steel plate cell 2 is installed, as shown in FIG. 2, plate-shaped offshore steel plate arcs 3S and land-side steel plate arcs 3L curved so as to close the space between the steel plate cells 2 are driven into the seabed ground 7. It is. At this time, it is desirable that the land-side steel sheet arc 3L has a double structure. This is because the water barrier property of the revetment structure 1 is improved. The steel plate arcs 3S and 3L driven into the seabed ground 7 are fixed to the steel plate cell 2 by underwater welding, and the filling material 5 is introduced into the inside thereof. A plurality of steel plate arcs 3S and 3L are installed by the above process (steel plate arc installation process).

  Next, the upper surface body 4 is installed on the upper surfaces of the steel plate cell 2 and the steel plate arc 3 (upper surface body installation step). Further, the projecting body 11 is installed on the upper surface body 4 (projecting body installation process). Further, the support member 15 is installed on the upper surface body 4 and on the land side L of the protruding body 11 (support member installation step). Here, the upper surface body 4, the protruding body 11, and the support member 15 may be formed by placing concrete on site, or may be transported and installed on the site after being formed in a factory or the like. When the upper surface body 4 is formed in a factory or the like, the construction period can be shortened. Moreover, the upper surface body 4 should just be formed so that the upper surface of the steel plate cell 2 and the steel plate arc 3S, 3L may be covered, and can employ | adopt various shapes.

  Next, a plurality of wave-dissipating blocks 12 are arranged on the upper surface of the upper surface body 4 and on the offshore side S of the projecting body 11 to form the block composite 13. The upper surface of the block composite 13 is configured to incline upward from the offshore side S toward the land side L (wave-dissipating block installation step). The inclination angle of the upper surface of the block composite 13 with respect to the horizontal is, for example, 15 ° to 55 °. Finally, the land side L of the revetment structure 1 is reclaimed by the landfill 9.

  Next, the wave-dissipating effect by the revetment structure 1 will be described. As illustrated in FIGS. 3 and 4, when the wave F arrives at the revetment structure 1, the seawater of the wave F colliding with the block composite 13 enters the block composite 13, and the internal void and the seawater are replaced. Due to the friction (resistance) at the time of this replacement, the energy of the wave F is attenuated, and a high wave extinction effect can be obtained. The energy of the wave F is also attenuated when the wave F collides with the block composite 13. In order to obtain an excellent wave-dissipating effect, as described above, it is preferable to set the porosity inside the block composite 13 to 45% to 70%.

  By adjusting and appropriately setting the number and arrangement of the wave-dissipating blocks 12, it is possible to obtain a sufficient wave-dissipating effect for various environmental conditions. Moreover, since various adjustments of the wave-dissipating block 12 can be performed flexibly according to the environmental conditions at the site, the revetment structure 1 has a highly versatile structure. Therefore, according to the revetment structure 1, a sufficient wave-dissipating effect can be obtained even for wake waves and wind waves having various wavelengths. Moreover, since the general-purpose wave-dissipating block 12 can be used, it is easy to obtain and is advantageous in reducing the cost.

  Since the upper surface of the block complex 13 is inclined upward from the offshore side S toward the land side L, the wave F that collides with the block complex 13 is difficult to be reflected. Therefore, seawater is easily taken into the block composite 13, and it is becoming more and more advantageous to obtain a high wave-dissipating effect. In order to suppress the reflection of the wave F colliding with the block composite 13, the inclination angle of the upper surface of the block composite 13 may be set to 15 ° to 55 ° as described above. If the inclination angle exceeds 55 °, it is difficult to suppress the reflection of the wave F, and if it is less than 15 °, the wave-dissipating effect due to the collision with the wave F is reduced. More preferably, the inclination angle is set to 25 ° to 45 °, and more preferably 34 ° to 38 °.

  When the upper surface of the upper surface body 4 is set at a position lower than the average water level WL, the period during which the seawater of the incoming wave F can be taken into the block complex 13 becomes longer, and the position is lower than the envy average low tide level LWL. If set, the period becomes even longer. That is, when the position of the upper surface of the upper surface body 4 is set in this way, the seawater of the incoming wave F can be taken into the block complex 13 regardless of the tides, so that it is easy to obtain a sufficient wave-dissipating effect constantly. Become. If the upper surface of the upper surface body 4 is set to be 2 m or more lower than the envy average low tide level LWL, the upper surface of the upper surface body 4 is not exposed on the sea surface even at the lowest position of the amplitude of the wave F, and the wave F is always blocked. It is possible to obtain a wave-dissipating effect by colliding with the composite 13.

  In many cases, the wave F directly collides with the block composite 13, but depending on the water level, along the indentation extending up and down of the continuous arc-shaped wall of the steel plate cell 2 and the steel plate arc 3, It can also be expected that the seawater moves upward and enters the block composite 13 to attenuate the energy of the wave F. In FIG. 3, the wave F arriving at right angles to the revetment structure 1 is illustrated, but even in the case of the wave F arriving obliquely, the seawater near the sea surface of the wave F is It can be expected to be guided to the block complex 13 along the depression. That is, a wave-dissipating effect due to the cooperation between the arc-shaped wall and the block composite 13 can be expected.

  The length in the horizontal direction (left and right direction in FIG. 1) from the offshore side end to the land side end of the block complex 13 constituted by the wave-dissipating block 12 is, for example, 7 to 12 m, preferably 8 to 10 m. To do. If the length is shorter than 7 m, the wave-dissipating effect by the block composite 13 becomes too small. Even if the length is longer than 12 m, the wave-dissipating effect cannot be obtained as long as the length is commensurate. This is because it makes it difficult to carry out the cargo handling work.

  In this embodiment, since the cross-sectional shape of the projecting body 11 is substantially L-shaped, the weight of the wave-dissipating block 12 on which a force to move to the land side L by the colliding wave F acts is stabilized. Can be supported. Thereby, the movement of the wave-dissipating block 12 to the land side L is prevented, and it becomes easy to ensure the wave-dissipating effect stably.

  Various shapes can be adopted as the cross-sectional shape of the projecting body 11, and for example, it can be substantially I-shaped. By installing the support member 15, it is possible to more reliably prevent the wave-dissipating block 12 and the protrusion 11 from moving to the land side L. If the wave-dissipating block 12 hardly moves even when the wave F collides, either the protruding body 11 or the support member 15 can be omitted.

  In order to adjust the wave-dissipating effect by changing the arrangement of the wave-dissipating block 12, for example, after the revetment structure 1 is built, the amount of reflected waves generated from the revetment structure 1 is investigated and grasped by observation. According to this result, the number of wave-dissipating blocks 12 and the arrangement position thereof can be changed, and optimization of the wave-dissipating effect can be realized.

  Specifically, the number, stacking, arrangement, etc. of the wave-dissipating blocks 12 with respect to changes in the seafloor topography associated with the construction of the revetment structure 1 and changes in wave wavelength due to sediment deposition associated with changes in ocean currents, etc. By changing the shape, the shape and the like of the block composite 13 are changed, and the revetment structure 1 can obtain an optimum wave-dissipating effect. In the survey before the construction of the revetment structure 1, the environmental conditions could not be predicted accurately, or because the environmental conditions changed after the survey, sufficient wave-breaking effects could not be obtained after the construction of the revetment structure 1 Even if it becomes clear, the revetment structure 1 can obtain a sufficient wave-dissipating effect by changing the shape or the like of the block composite 13 according to the on-site environmental conditions.

  In FIG. 5, the outline of the revetment structure 1A used as another embodiment of this invention is shown. The block composite 13 </ b> A of the revetment structure 1 </ b> A is disposed on an inclined surface 16 inclined upward from the offshore side S to the land side L of the inclined body 14 formed on the upper surface of the upper surface body 4. It is desirable that the inclined body 14 is made of concrete like the projecting body 11A and the support member 15A. In this embodiment, the support member 15A has a triangular cross section.

  By employing the inclined body 14, the seawater (wave F) that has entered the block complex 13 </ b> A is easily discharged to the offshore side S along the inclined surface 16. Therefore, the space | gap and the seawater inside the block composite 13 become smooth, and it can be expected to improve the wave-dissipating effect. Moreover, the number of wave-dissipating blocks 12 required for the revetment structure 1 can be suppressed, and the construction period can be shortened.

  In addition, the upper surface body 4, the protruding body 11A, the support member 15A, and the inclined body 14 may be formed independently, or may be integrally formed by combining arbitrary ones. The wave-dissipating block 12 constituting the block complex 13A may be constituted by two-tiered stacking in two upper and lower stages, or may be constituted by multi-tiered stacking, or may be constituted by random stacking. . These configurations can be similarly adopted in the embodiment shown in FIGS.

  The steel plate cell 2B illustrated in FIG. 6 is configured to have a step on the upper end side. This step is configured such that the land side L is higher than the offshore side S. Although not shown, the offshore steel plate arc 3S is configured at the same height as the offshore side S of the steel plate cell 2B, and the land side steel plate arc 3L is configured at the same height as the land side L of the steel plate cell 2B. And the upper surface body 4 is formed according to the height of the offshore side S of the steel plate cell 2B. Other structures are constructed in the same manner as the above-described embodiment.

  With the configuration employing the steel plate cell 2B and the like, the revetment structure can improve water shielding. This is because the land-side L steel plate cell 2A and the land-side steel plate arc 3L formed higher than the offshore side S make it easier to suppress the penetration of seawater and the like from the offshore side S to the land side L.

DESCRIPTION OF SYMBOLS 1, 1A Revetment structure 2, 2B Steel plate cell 3 Steel plate arc 3S Oki side steel plate arc 3L Land side steel plate arc 4 Top surface body 11, 11A Projection body 12 Wave-dissipating block 13, 13A Block complex 14 Inclined body 15 Inclining body 15 Support member 16 Slope S offshore L land

Claims (5)

Steel plate cells driven into a plurality of seabeds arranged side by side at intervals, steel plate arcs driven into the seabed connecting between adjacent steel plate cells, and the top surfaces of the plurality of steel plate cells and steel plate arcs In the revetment structure provided with the formed upper surface body,
The upper surface body is made of concrete, and the lower surface thereof is disposed in a horizontal state so as to cover the upper surface of the steel plate cell and the steel plate arc,
A projecting body protruding from the upper surface of the upper surface body and extending in the horizontal direction of the steel plate cells, and a plurality of wave-dissipating blocks disposed on the upper surface of the upper surface body on the offshore side of the projecting body. And
The upper surface of the block complex composed of a plurality of wave-dissipating blocks is inclined upward from the offshore side to the land side, and the block complex is set to a height at which the wave collides and does not overtop. A revetment structure characterized by that.   The revetment structure according to claim 1, wherein an upper surface of the upper surface body is set at a position lower than an average water level.   The revetment structure according to claim 2, wherein an upper surface of the upper body is set at a position lower than a low tide water level.   The block complex is disposed on an inclined surface that is inclined upward from the offshore side to the land side of a concrete inclined body formed on the upper surface of the upper surface body. Revetment structure described in 1. The upper end of the steel plate cell has a shape with a step protruding upward on the land side compared to the offshore side, and the steel plate arc on the offshore side is configured at the same height as the offshore side of the steel plate cell, The steel sheet arc is configured at the same height as the land side of the steel sheet cell,
The revetment structure according to any one of claims 1 to 4, wherein the upper surface body is formed in accordance with a height on an offshore side of the steel plate cell.

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