JPH0611976B2 - How to build an underwater structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for constructing an underwater structure such as a breakwater, a breakwater, a seawall, a jetty, and the like. The present invention relates to a method for constructing an underwater structure in which stones are not scattered or scoured at a foundation having a slope formed.

[Prior Art] For example, when constructing a breakwater, as shown in Fig. 5, stones such as rubble stones are put into water to form a foundation mound 1a, and caissons 2a are installed on both sides of the foundation mound. A general method is to fix the placed root block 3a. In the case of other underwater structures as well, it is constructed by stone-like materials called rubble stones, back-fill stones, rubble stones, etc., made of natural or artificial rocks and slag, and caisson, irregular shaped blocks, etc.

[Problems to be solved by the invention] However, in the case of the breakwater shown in Fig. 5, if the water depth is considerable, stones thrown in from the work boat are scattered especially on the front line of the foundation mound 1a. However, the basic mound 1a having the actual slope B that is more gently inclined than the planned slope A is formed. Therefore, if only the amount of stones estimated at the time of designing is applied, the top end surface C of the foundation mound 1a becomes low, which causes a problem in the function as a breakwater. In addition, it is uneconomical to add extra stones in order to bring the top surface C to the planned height.

Furthermore, after the construction of the underwater structure is completed, the slope part of the foundation mound 1a is scoured by waves, tidal currents, etc., and the slope collapses, resulting in a caisson 2a, root block 3a, etc. Tends to be unstable.

The present invention solves such a problem, and even if the water depth is considerably deep, it is possible to form a foundation mound and other stone-like foundations as designed without the need for extra stones, and after completion of construction. Provides a method of constructing an underwater structure with a foundation that is free of scour.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a first slope maintenance in which two long block bodies are connected to each other by a connecting piece with a proper distance therebetween. A block is installed on the bottom of the water, and stones are charged between the blocks, and the stones are deposited over the block to an appropriate height to form a first deposit having a trapezoidal cross section in the width direction. When this is done, the second slope protection block in which the two long block bodies are connected to each other by a connecting piece with a spacing approximately equal to the width of the top surface of the first deposit Are installed so as to match the respective shoulders of the first deposit facing each other, and the operation of further introducing a stone-like object is repeated to form a base portion of the stone-like object.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 to 4 show an embodiment of the present invention. First, as shown in FIG. 1, two long block bodies 11, 11 made of concrete, for example, having an end face L shape, are predetermined. They are arranged back to back with a space between them, and they are connected to each other by connecting parts 12 made of a plurality of parallel shaped steels and fixed to each other. The sheet-like material 13 is used as a block body 11, 11
And the first slope protection block 1 laid on the lower surface of the connecting piece 12 and fixedly fixed thereto, and the block bodies 11 and 11 are fitted to both planned slopes 21 and 21 of the water bottom 2, respectively. The sheet-like material 13 is placed on the bottom 2 of the water.
Lay in In this way, the slope protection block 1 is installed adjacent to each other in advance over all the planned construction points of the underwater structure, or is sequentially installed depending on the progress of the construction.

Next, as shown in FIG. 2, a stone-like object 4 such as a rubble loaded on the work boat 3 is put into water and the back-to-back block body 1 is placed.
The stones 4 are deposited between 1 and 11 and over the block bodies 11 and 11 to a proper height to form a first deposit 6 having a trapezoidal cross section in the width direction. At this time, the injection of the stone-like object 4 is stopped and, for example, a plurality of long block bodies 51, 51 made of concrete having an end face convex shape and having a length substantially equal to the width of the top end face 62 of the deposit 6 are formed. The second slope protection block 5 configured to be connected and fixed to each other by the connecting piece 52 made of a wire rope, and the block bodies 51, 51 are the shoulders of the deposit 6 while the connecting piece 52 is tensioned. They are sequentially installed adjacent to the top face 62 so as to match the parts 61, 61, respectively.

After that, the stone-shaped material 4 is further charged and piled up to a predetermined height to form a foundation mound 7 as shown in FIG. Then, as shown in FIG. 4, the top end surface of the basic mound 7
An underwater structure is constructed by placing the caisson 8 and the root block 9 at 71.

Underground structure foundation mound 7 constructed in this way
Is the block body 11, 11 of the upper and lower slope maintenance blocks 1, 5.
And 51, 51 front faces 11a, 11a and 51a, 51a are slopes.
It is installed so as to be exposed to 63, 63 and prevents the scattering of the stone-like object 4 at the time of charging, and forms slopes 63, 63 with the inclination angle as designed. Depending on the height of the foundation mound 7, the second method In some cases, two or more slope protection blocks, in which the spacing between the block bodies becomes smaller than that of the surface protection block 5, may be installed.

The block bodies 11, 11 and 51, 51 connected by the connecting pieces 12, 52 embedded in the foundation mound 7 respectively receive the stone-like object 4 along the slopes 63, 63 and prevent the collapse. The slopes 63, 63 are maintained at a predetermined inclination angle. Also,
The sheet-like material 13 laid on the water bottom 2 covers the water bottom ground at the tip of the slope to prevent scouring due to waves or tidal currents and stabilizes the foundation mound 7.

However, when the water bottom 2 is rock and there is no concern about scouring, a slope conservation block having no sheet-like material 13 may be installed.

Needless to say, the present invention is applied to an underwater structure having a configuration other than that of the above-described embodiment, as well as the basic mound 7
The slope protection blocks 1 and 5 are installed over the entire length of the slope of the foundation portion illustrated in 1. above.

[Effects of the Invention] According to the present invention, a block body connected to each other by a connecting piece is installed on the front line of the bottom of the water and in the middle of the slope to form a foundation part made of stones such as rubble stone, backfill stone, and rubble stone. As a result, the stones are scattered on the front line at the time of construction, and the slope becomes gentler than the planned slope, the crown surface becomes lower, or the extra stones are not needed. However, since the block body receives the stones on the slope, it is possible to form a fairly high foundation as designed.

And since the two blocks are connected to each other by the connecting piece and their outward movement is regulated, there is no concern that they will collapse together with the stone-like object on the slope, and they are stably fixed, and the foundation is kept even after construction. It maintains a predetermined shape.

[Brief description of drawings]

1, 2, 3 and 4 are perspective views for explaining the steps in one embodiment of the present invention, and FIGS. 5 and 6 are sectional views showing a conventional example of an underwater structure. . 1,5 …… Slope protection block, 11,51 …… Block body,
12,52 …… Connecting piece, 2 …… Water bottom, 4 …… Stony, 7…
… Basic mound, 63… Slope.

Claims (1)

[Claims] 1. A first slope protection block in which two long block bodies are appropriately spaced apart and are connected to each other by a connecting piece, and a first slope protection block is installed on the bottom of the water, and a stone-like object is introduced between the block bodies. However, when the stones are deposited over the block body to an appropriate height to form a first deposit having a trapezoidal cross section in the width direction, it is almost equal to the width of the top end face of the first deposit. A second slope protection block, in which two elongated block bodies having a distance are connected to each other by a connecting piece, is provided on each of the opposite shoulders of the first deposit, each block body having a second slope protection block. A method for constructing an underwater structure, characterized in that the foundation is made of stones by repeating the work of installing the stones so as to match and further introducing the stones.