JPH06116957A - Construction method of underwater foundation in break-water, etc. - Google Patents

Abstract

PURPOSE:To shorten a construction period by throwing footing riprap on the sea-bed, injecting hardener from a specific position on the surface of the footing riprap, and combining an injection part with the riprap to form an underwater foundation of a construction. CONSTITUTION:Excavation of sea bed on which a breakwater is installed is made from land or sea, throwing of footing riprap 10 starts from a complete part of the excavation of sea bed, and a specific thickness of the footing riprap and a surface of slope are ensured so as to have the planned shape of an underwater foundation to construct an underwater foundation body 12. After that, a breakwater body 14 is installed at a specific position on the body 12, and properly coating blocks 16 are arranged to the base of the body 14. Then, hardener 18 is injected into a gap on the surface in the body 12 to form a specific part 20a of the slope 20 as a unit, at the same time, to make it as a block. According to the constitution, leveling work of the footing riprap made by a diver, etc., can be eliminated, and construction work can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing an underwater foundation, and more particularly to a method for constructing an underwater foundation for a structure such as a breakwater.

[0002]

PRIOR ART AND PROBLEMS TO BE SOLVED BY THE INVENTION Conventionally,
For the underwater foundation used when constructing breakwaters, etc., first gravel rubble on the seabed and leveling work by a diver, then covering this foundation rubble with stones larger than this rubble, and further It is constructed by arranging a covering block on the upper surface.

By the way, in recent years, various port facilities including breakwaters are often developed offshore, and along with this, the construction is becoming larger and deeper. And such a tendency is that the leveling work efficiency by the diver of the rubble of the foundation is a big factor that influences the progress of the whole construction.

However, since the diving time is extremely shortened as the water depth becomes deeper, it is difficult to secure the divers in recent years even though a large number of dives are required for underwater work. Therefore, it has been pointed out that various problems to be solved, such as a long construction period and a high construction cost, should be solved.

[0005]

Therefore, in the present invention, a solidifying material is injected from a predetermined place on the surface of a foundation rubble thrown into the seabed, and the rubble at the injected portion is integrated to form an underwater foundation for a structure such as a breakwater. By adopting the method, not only the work of leveling the rubble of the foundation by the diver, but also the work of installing the covering stone to be placed on the rubble of the foundation will be omitted.

In this case, if a water-permeable sheet member is inserted in advance at a predetermined depth from the surface of the rubble, or if a crushed stone layer having a small grain size is formed and a solidifying material is injected,
It is possible to improve the efficiency of the injection work using the solidifying material, and it is preferable to use underwater non-separable concrete as the solidifying material.

[0007]

In the present invention, an underwater foundation for a structure can be formed simply by filling a solidifying material from a predetermined place on the surface of the foundation rubble and integrating the rubble in the filled portion as it is. Not only can the construction period be shortened by omitting the leveling work of rubble stones, but also the construction cost can be reduced.

[0008]

EXAMPLES Next, a method of constructing an underwater foundation for a structure according to the present invention will be described in detail below with reference to the accompanying drawings, exemplifying a case of constructing an underwater foundation for a breakwater installed at a port entrance. .

That is, in the method of constructing an underwater foundation according to the present invention, first, a floor moat is formed from the land and / or the sea at the place where the breakwater is to be installed. In this case, the floor excavation work may be carried out as necessary and can be omitted.

Then, the rubble 10 for the foundation is started from the portion where the floor moat is finished, and a predetermined stone thickness and slope are secured so that the shape of the underwater foundation is assumed, and the underwater foundation body 12 is formed. (See Figure 1). As the shape of this foundation rubble, the shape of the foundation rubble when constructing an underwater foundation by the conventional method is 10 kilograms / piece to 800 kilograms / piece, and the shape of the covering stone is 300 kilograms / piece to 800 kilograms / piece. Assuming the use of
From kilogram / piece to 800 kilogram, that is,
By unifying the shape of the foundation rubble, the leveling work of the foundation rubble surface is omitted.

Next, the underwater foundation body 1 thus formed
The breakwater main body 14 is installed at a predetermined position on the ground 2, and the covering block 16 is appropriately arranged at the base of the breakwater main body 14 (see FIG. 2).

The underwater foundation body 1 thus formed
The solidified material 18 is injected into the void portion of the surface of 2 to integrate the predetermined portion 20a of the slope 20 and form a block. In this case, it is preferable to use underwater non-separable concrete as the solidifying material 18. If the solidifying material 18 (underwater non-separable concrete) is directly filled with the tremie pipe 24 from the mixer ship 22 as shown in the figure. Good (see Figure 3).

Further, when the solidifying material 18 is injected from the voids on the surface of the underwater foundation body 12, as shown in FIG. 4, when the foundation rubble 10 is put in, a predetermined depth position from the surface of the underwater foundation body 12 is reached. If the water permeable sheet member 26 is inserted in advance and the solidifying material 18 is injected into the position where the water permeable sheet member 26 is disposed, efficient injection can be performed, which is preferable. In this case, instead of the water permeable sheet member 26, the solidified material 18 may be injected at a predetermined depth position from the surface of the underwater foundation body 12 by forming, for example, a crushed stone layer having a small particle size. It goes without saying that the same effect can be obtained.

Furthermore, when the solidified material 18 is injected from the voids on the surface of the underwater foundation body 12 to integrate the foundation rubble stone 10, it is not always necessary to integrate the entire surface, and for example, it is assumed. The intersections of the lattice-shaped figures may be integrated (see FIG. 5), or may be randomly injected and integrated.

[0015]

As described above, according to the method of constructing an underwater foundation according to the present invention, the solidified material is injected from a predetermined place on the surface of the underwater foundation body formed by the foundation rubble to remove the rubble of the filled portion. Since it is only integrated, it is possible to omit the work of leveling the rubble of the foundation by the diver, and also the work of installing covering stones placed on this rubble, so shortening the construction work of the underwater foundation and construction cost Can be reduced.

Further, when the water permeable sheet member is inserted in advance at a predetermined depth position from the surface of the rubble, it is possible to improve the efficiency of the injection work with the solidifying material, and further, the injection work with the solidifying material. Since it is not necessary to perform the entire surface, it has various advantages such as facilitating the construction.

Although the preferred embodiment of the method of constructing an underwater foundation in a breakwater according to the present invention has been described above, the present invention is not limited to this embodiment and does not depart from the spirit of the present invention. It goes without saying that various changes can be made in.

[Brief description of drawings]

FIG. 1 is an explanatory diagram in the case of constructing an underwater foundation for a breakwater as a preferred embodiment of a method for constructing an underwater foundation according to the present invention, and is an explanatory view of a state where an underwater foundation body is formed by throwing in a rubble of foundation. Is.

FIG. 2 is an explanatory view showing a state in which a breakwater is constructed on the underwater foundation body shown in FIG.

FIG. 3 is an explanatory diagram showing a state in which a solidifying material is filled into the underwater foundation body shown in FIG. 2 to integrate a predetermined portion and form a block.

FIG. 4 is an explanatory diagram when a water-permeable sheet member inserted in the underwater foundation body is used when filling the underwater foundation body shown in FIG. 2 with a solidifying material.

FIG. 5 is an explanatory plan view showing an example when the solidified material is filled in the underwater foundation body to integrate the foundation rubble.

[Explanation of symbols]

10 Foundation rubble, 12 Underwater foundation body, 14
Breakwater main body, 16 coated blocks, 18 solidifying material,
20 slopes, 22 mixer ships, 24
Tremie tube, 26 water permeable sheet member

Claims (4)

[Claims] 1. An underwater foundation for a structure is formed by performing foundation rubble on the seabed and then injecting solidifying material from a predetermined location on the surface of the foundation rubble to integrate the rubble at the injected portion. How to construct an underwater foundation for a breakwater. 2. The method for constructing an underwater foundation for a breakwater or the like according to claim 1, wherein the solidifying material is injected through a water permeable sheet member at a predetermined depth position from the surface of the foundation rubble. 3. The underwater in a breakwater or the like according to claim 1, wherein a crushed stone layer having a small grain size is formed at a predetermined depth position from the surface of the foundation rubble, and the solidifying material is injected through this crushed stone layer. How to build the foundation. 4. The method for constructing an underwater foundation for a breakwater or the like according to any one of claims 1 to 3, which comprises using underwater non-separable concrete as a solidifying material.