JPH0475963B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a mound for protecting the base of a breakwater, and in particular to a footing mound for a breakwater protecting a sloping mound.

[Conventional technology]

Traditionally, concrete breakwaters have been built in areas that are subject to severe erosion due to waves from coasts and rivers.
The tip of the base of the breakwater is eroded by strong breaking waves at low water depths and by overlapping waves at high water depths.
This problem is gradually spreading, and accidents leading to the destruction of breakwaters are occurring frequently.

Generally, when the water depth in front of the breakwater is less than 1/2 of the wave height, it is calculated as a breaking wave, and when it is more than 1/2, it is calculated as a duplicate wave. The actual state of overlapping waves is still poorly understood, but in reality, some of the waves that hit the ground create pressure from below the ground and scatter the covering blocks on slopes. When constructing a breakwater, the cost of constructing a breakwater will increase even if the slope of the mound is reduced by deepening the wall, or even if the wall is kept at the normal height and the mound is built longer than the original ground. Therefore, it is preferable to build a normal quay and cover the mound according to the slope of the original ground.

In this case, the slope is naturally covered with concrete blocks in accordance with the slope of the original ground, but in the case of a steep slope, the concrete blocks are significantly scattered due to the uplift force within the mound caused by the overlapping waves.

[Problem that the invention seeks to solve]

Therefore, there has been a need for a covering mound construction method that not only prevents the mound from being blown away by overlapping waves but also allows it to be constructed on a steep slope, from both the safety and economical standpoints of the breakwater.

[Means of problem solving]

The present invention was completed by researching the properties of overlapping waves in order to solve the above problem, and consists of a column whose long sides are the bottom, top, and both sides, and a plurality of protrusions from both sides. Concrete blocks that extend alternately, where the side projections extend from one side of the column, there is a shape in which the side projections do not extend from the other side of the column. In a mound for protecting the base of a breakwater using an integrally formed concrete block for covering the slope,
A large number of the above-mentioned columns having approximately the same length as the inclined surface are arranged in parallel, the tips of the side protrusions are in contact with or close to the side surfaces of the adjacent columns, and the columns are parallel to each other through the protrusions. They are arranged side by side, and heavy large blocks are placed and fixed on the upper and lower horizontal surfaces of both ends of each of the concrete blocks for slope covering.

The mound of the present invention takes advantage of the natural shape of the ground as much as possible, and the ground is leveled so that there is an inclined part between the horizontal ground. Therefore, the slope of the slope portion becomes large, but in the present invention, the slope is 1:2 to 1:2.
Concrete blocks will not scatter even on steep slopes of about 1:1.5.

The concrete block of the invention has long columns. This column has a length approximately equal to the length from the top end to the bottom end of the inclined surface. Therefore, the slope can be covered from the top end to the bottom end with one column. This column has side protrusions extending alternately from both sides. That is, in a region where a side protrusion extends from one side, nothing extends from the other side. The number of side protrusions is 3 or more, preferably 5 to 7 on both sides. Therefore, when using this block to cover a sloped surface, the thickness and spacing of the side protrusions should be adjusted so that the side protrusions can be inserted into the side of the adjacent block from which nothing extends. It is fine as long as it is adjusted.

Furthermore, it is preferable that a through hole extending from the bottom surface to the top surface is bored in the column, preferably in the center thereof. In recent years, as concrete blocks have become larger and larger, the uplift force caused by overlapping waves has increased, and this method is effective in cases where it is insufficient to discharge pressurized water from the gaps between the columns. If the pore area on the bottom surface is larger than the pore area on the top surface, pressure water can be discharged from the bottom surface more smoothly, improving durability.

In addition, when arranging these blocks on the ground soil or crushed stone, in order to make the construction more stable, it is recommended to provide a shoe on the back side of the side protrusion or on the back side of the column, and bury this shoe in the crushed stone or ground soil. is preferred. Further, in some cases, it is preferable to stack such concrete blocks in two or more stages.

In the present invention, the slope is made somewhat steep, and horizontal surfaces are provided above and below this slope. The concrete block of the present invention having an integrally formed inclined surface,
The blocks according to the present invention are lined up with both ends facing toward the seawall and the sea to protect the slope, and the blocks according to the present invention have horizontal ground at both the upper and lower ends, and a large heavy block is placed on this horizontal ground, and the block according to the present invention Secure both ends of the block with weight blocks placed on horizontal ground.

[Effect]

In the present invention, a long column is used and the slope is covered with one concrete block in parallel, so the weight of each force is large and it is difficult to scatter. Moreover, since the concrete block of the present invention has side protrusions extending alternately from both sides, the side protrusions of the adjacent block can be attached to the portion of one side of the first block where the side protrusions do not extend. When inserted, the side protrusions of adjacent blocks will intertwine as shown in Figure 1, creating the effect that the entire slope is integrated vertically and horizontally, and even if the slope is steep, there will be no overlap. It is possible to prevent the covering block from scattering due to uplift force caused by waves. Further, in the mound of the present invention, both ends of the pillar bodies of the blocks of the present invention arranged in parallel and covering the inclined surface are fixed by weight blocks placed on horizontal surfaces provided above and below the inclined surface. Therefore, lateral movement of the block covering the inclined surface is prevented by the intertwining of the side protrusions, and vertical movement is prevented by the weight blocks placed on the upper and lower horizontal surfaces. As a result, even on a fairly steep slope, concrete blocks are prevented from being blown away by returning waves.

〔Example〕

FIG. 1 is an assembled view of one embodiment of concrete blocks according to the present invention, viewed from a direction perpendicular to a slope, and FIG. 2 is a perspective view of the blocks viewed from below. 1 is the column, 2 is the first side 3
Similarly, a side protrusion 5 extends from the second side surface 4 . In Fig. 1, the distance between the blocks is widened for easy understanding, but the tips of the side protrusions 2 touch or approach the side faces 4 from which the side protrusions of adjacent blocks do not extend. . Even in this state, the pressure water under the concrete block can be discharged from the space between the blocks, but if the through hole 6, especially the diameter of the lower surface is larger than the diameter of the upper surface, is provided, the pressure water can be discharged even more smoothly. It will be done. Reference numeral 7 in FIG. 2 indicates a shoe, which is provided on the back surface of the side projection in this embodiment, but there is no particular limitation on the location where it should be provided as long as it is on the back surface of the column 1. The through hole 6 has a large diameter on the back surface, but the diameter on the top surface is made smaller as shown in FIG.

FIG. 3 is an explanatory cross-sectional view showing one embodiment of a foot protection mound for a breakwater of the present invention constructed on the coast on the Sea of Japan side for a breakwater with a water depth of 15 m or more. In the drawing, the part indicated by the broken line is the 1/4 point of the maximum wavelength. The maximum wavelength is the average value of the maximum wavelength and wave height statistically obtained by continuously measuring the wavelength and wave height at each port. This is the basis for strength calculations. According to conventional experiments and experience, it has been found that in areas with high water depths, especially in mounds with a depth of 15 m or more, the areas with 1/4 wavelength of the maximum wavelength are the areas where the most severe scour occurs.

11 is a breakwater, 12 is a water surface, and 13 is crushed stone. A large weight block 14 was laid in front of the base of the breakwater. In this embodiment, a concrete block having a horizontal protrusion on the upper surface was used, but any heavy concrete block such as a rectangular one or one having an upward protrusion may be used.
15 is a concrete block according to the present invention, 6 is a through hole, and 7 is a shoe. The slope of the foot hardening section using this block was set to 1:2, but it is also possible to make the slope even steeper to about 1:1.5.
Reference numeral 16 indicates a root block for preventing the concrete block 15 according to the present invention from sliding down. Adjacent to this root stop block 16 is a sinking frame 1.
7 was buried. In this embodiment, the sinking frame 17 is a square type with horizontal bars on the bottom and sides, and the inside is filled with crushed stone. The position of this sinking frame 17 is 1/4 of the maximum wavelength
It was about 2/3 of the point on the breakwater side. Crushed stone was further laid in front of sinking frame 17, leaving the ground as it was in front of the 1/4 point of the maximum wavelength. That is, the third
In the figure, the part indicated by the two-dot chain line is the initial ground.

A submersible frame is a wooden frame filled with stones that has been used since ancient times for flood control in rivers and other areas. Although this sinking frame was used in this embodiment, it may be made of wood like the conventional one, but it is preferable to use concrete and assemble it after all the members are cast into a flat plate.

One year later, the concrete blocks of the foot hardening mound of the present invention did not scatter and maintained the same shape as when constructed. Furthermore, although deep scour occurred between the 1/4 point and sinking frame 17, according to this example, due to the effect of the sinking frame, the scoured soil and returning waves were scattered further ahead of the 1/4 point. Ground 1 where crushed stone and ground soil are integrated and integrated
8 was formed. Therefore, this unified ground 1
8, the returning waves also lost their scouring power, and equilibrium was reached with the topography shown by the solid line in Figure 3. on the other hand,
Although the slope covered with the conventional irregularly shaped blocks had a gentle slope of 1:3, scattering of the blocks due to water pressure was observed.

〔effect〕

The breakwater footing mound of the present invention is particularly effective when used for mounds of vertical breakwaters on coasts and ports where rapid waves often crash, such as those on the Sea of Japan side, and effectively covers the base and mounds of breakwaters. As a result, concrete blocks are prevented from being blown away by overlapping waves, and the angle of inclination can be increased, especially on sloped surfaces, making it possible to economically construct a safe breakwater.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention. Figure 1 is an assembled view of the foot protection mound seen from the slope, Figure 2 is a perspective view of the concrete block seen from below, and Figure 3 is a sectional view of the foot protection mound. It is. In the drawings, 1 is a column, 2 and 5 are side projections,
3 and 4 are side surfaces, 6 is a through hole, 7 is a shoe, 11 is a breakwater, 12 is a water surface, 13 is crushed stone, 14 is a weight block, 15 is a concrete block, 16 is a root block, 17 is a sinking frame, 18 is It is a unified ground.

Claims (1)

[Claims] 1 A column whose long sides are the bottom, top, and both sides,
A concrete block having a plurality of protrusions extending alternately from both sides, where a side protrusion extends from one side of the column, there is no side protrusion from the other side of the column. With a shape that does not extend,
In a mound for protecting the base of a breakwater using an integrally formed concrete block for covering a slope, a large number of the above-mentioned pillars of approximately the same length as the slope are arranged in parallel, and the tips of the side protrusions are adjacent to each other. In contact with or close to the side surfaces of the pillars, and arranging the pillars in parallel with each other through the projections, and on the upper and lower horizontal surfaces of both ends of each of the concrete blocks for covering slopes,
A breakwater footing mound characterized by placing and fixing large, heavy blocks.