JP2958542B2 - Construction method of anchor body in soft underground - Google Patents

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 anchor for mooring an object to be moored, such as a workboat, on a submarine ground covered with a thick soft layer.

[0002]

2. Description of the Related Art Conventionally, in the case of mooring an object to be moored, such as a workboat, in a marine work, a concrete block is sunk or a pile is put into place, and these are anchored. The mooring line is connected to moor the object to be moored.

[0003]

SUMMARY OF THE INVENTION The above prior arts include:
The following problems exist. <A> When using concrete blocks or piles as anchors, a production period including a curing period for them or a casting period is required, which leads to a longer construction period. <B> Work to transport and sink existing heavy concrete,
Alternatively, the work of placing a pile requires a lot of work. <C> In a place where a thick soft layer where concrete lumps spontaneously settle is deposited thickly, it is difficult to predict how far the sink will sink, and it is difficult to specify the place where the concrete is settled. <D> It is difficult to pull up and reuse concrete masses or piles that have been laid. <E> The method of mooring the pile driving ship itself for driving the piles is a problem.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an anchor body in a soft underground where the construction can be simplified and the construction period can be shortened. The purpose is to provide a construction method. That is, the present invention provides a support plate having an opening, and a bottomed bag body which is communicated with the opening portion of the support plate and is hung down on a soft underwater ground, and a mooring line is provided in the bag body. The anchor body connected with the anchor body is stored, sand is pressed into the bag body from the top of the anchor body, the bag body is expanded downward, and the anchor body is settled to a predetermined depth and installed.
This is a method of constructing an anchor body on soft underground. In addition, an anchor having an opening and a bottomed bag connected to the opening of the support plate and hanging therefrom is installed on a soft underground, and a mooring line is connected to the bag. The body is stored, the jet end of the air or water injection hose is fixed near the upper part of the anchor body, sand is pressed into the bag body from the upper part of the anchor body, the bag body is expanded downward, and the anchor body is expanded. After setting the jet hose down to the specified depth and installing it, air or water is jetted from the jet end of the jet hose, and the mooring line is pulled up while the sand on the anchor body is stirred and liquefied, and the anchor body is removed. This is a method of constructing an anchor body on soft underground. Further, in the above method, during or after the sedimentation of the anchor body in the soft underground, the anchor body in the soft underground that vibrates and compacts the sand pressed into the bag body via the mooring line. The construction method. Further, in the above method, the present invention is a method for constructing an anchor body in a soft underground where a bag body is formed of a water-permeable material.

[0005]

An embodiment of the present invention will be described below with reference to the drawings. <A> Installation of Support Plate with Bag The support plate 1 is a steel plate or the like having an opening 11 at the center or the like as shown in FIG. The support plate 1 has a large area so that a sufficient reaction force can be taken on the ground surface so that the entire sand pile described below does not sink into the soft layer even in a place where the soft layer is thickly deposited. Used. Also, the opening 1 of the support plate 1
1 and the bottomed bag 2 is hung down. The bag 2 is made of a flexible material that can be contracted and expanded. When the bag body 2 is made of a water-permeable material, moisture in the surrounding ground can be absorbed by the sand piles, and the consolidation of the surrounding ground can be promoted.
Further, a press-fit end 31 of a press-fit hose 3 for press-fitting sand into the bag 2 is fixed to the opening 11 of the support plate 1. Then, the support plate 1 and the bag body 2 configured as described above are installed on soft ground as shown in FIG.

<B> Installation of Anchor Body The anchor body 4 can adopt various shapes as long as it has a sufficient pull-out resistance. For example, as shown in FIG. A disk can be used. The anchor body 4 may be given a weight using a steel plate or the like in order to easily settle into the soft ground described later. In addition, the anchor body 4 includes a mooring line 41 such as a chain.
And the other end of the mooring line 41 is connected to an offshore mooring object such as a workboat. Further, near the upper part of the anchor body 4, the jet end 51 of the air or water jet hose 5 is fixed. When the jetting end 51 is arranged upward, a sand liquefaction effect described later can be more effectively obtained. And the anchor body 4 comprised as mentioned above is installed in the bag body 2 installed on soft ground as shown in FIG.

<C> Press-in of Sand Next, as shown in FIG. 2, sand 6 is pressed into the bag 2 from above the anchor 4 through the press-in hose 3. Then, as shown in FIG. 3, the bag body 2 is expanded downward, the anchor body 4 and the injection hose 5 are settled to a predetermined depth, and the installation work of the anchor body 4 is completed.
As described above, the sand 6 is pressed into the bag body 2 to form a sand pile, and the anchor body 4 is positioned at the bottom of the sand pile, whereby a sufficient pull-out resistance required for mooring can be obtained. . In the meantime, while the anchor body 4 is submerged in the soft ground as described above or after the subsidence is completed, the sand 6 pressed into the bag body 2 via the mooring line 41 is subjected to vibration to compact the sand 6. Since the shear resistance of the pile can be increased, the pull-out resistance can be further increased.

<D> Removal of the anchor body When removing the anchor body 4 installed as described above,
As shown in FIG. 4, the mooring line 41 is pulled up and the anchor body 4 is removed while jetting air or water from the jet end 51 of the jet hose 5. In this way, the air 6 or the water is jetted from the jet end 51, whereby the sand 6 above the anchor body 4 is agitated and liquefied, and the shear resistance is reduced, so that the anchor body 4 can be easily pulled out.

[0009]

Since the present invention has been described above, the following effects can be obtained. <B> By inserting sand into the bag placed on soft ground to create a sand pile and positioning the anchor at the bottom of the sand pile, sufficient pulling resistance required for mooring can be obtained. . Therefore, unlike the concrete block and the pile, the production period including the curing period or the casting period is not required, and thus the construction period can be shortened.

<B> Since a simple operation of merely pressing sand into the bag body is sufficient, the construction can be simplified.

<C> Even in a place where the soft layer is thickly deposited, the reaction force against the settlement of the sand pile can be applied to the ground surface by the support plate. Therefore, the entire sand pile does not sink into the soft ground, and the construction can be performed as designed. Therefore, the present invention can be applied to a wide range of construction regardless of the location of the submerged place.

<D> By vibrating and compacting the sand in the bag body, the shear resistance of the sand pile can be increased, and the pull-out resistance of the anchor body can be increased.

<E> By making the bag body of a water-permeable material, moisture in the surrounding ground can be absorbed by the sand piles, and the compaction of the surrounding ground can be promoted. Therefore, the pull-out resistance of the anchor body can be further increased.

<F> When removing the anchor, the anchor is pulled out while blowing air or water into the bag. Therefore, the sand in the bag is stirred and liquefied, and the shear resistance is reduced, so that the anchor can be easily pulled out.

<G> Since the anchor body is removable,
Reusable and economical.

<H> After the completion of the construction, only the sand pile and the bag remain in the ground, so that there is no influence on the environment.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an anchor structure.

FIG. 2 is an explanatory view of an installation state of a support plate.

FIG. 3 is an explanatory diagram of a completed installation state of the anchor body.

FIG. 4 is an explanatory view of a method of removing an anchor body.

Claims (4)

(57) [Claims] 1. A support plate having an opening and a bottomed bag body which is communicated with the opening of the support plate and hung down are installed on a soft underground ground, and a mooring cable is provided in the bag body. An anchor in soft underground where the connected anchor body is stored, sand is pressed into the bag body from the top of the anchor body, the bag body is expanded downward, and the anchor body is settled down to a predetermined depth and installed. Body construction method. 2. A support plate having an opening and a bottomed bag body which is communicated with the opening of the support plate and is hung down on a soft underwater ground, and a mooring line is provided in the bag body. The connected anchor body is housed, the jet end of the air or water injection hose is fixed near the upper part of the anchor body, sand is pressed into the bag body from the upper part of the anchor body, and the bag body is expanded downward. At the same time, the anchor body and the injection hose are settled down to the specified depth and installed, and then air or water is injected from the injection end of the injection hose, and the mooring rope is pulled up while stirring and liquefying the sand above the anchor body. A method for installing anchors on soft underground to remove the body. 3. The softness according to claim 1, wherein the sand pressed into the bag body via the mooring line is compacted by vibrating the sand while the anchor body is submerged in the soft underground or after the subsidence is completed. Construction method of anchor body on underwater ground. 4. The bag according to claim 1, wherein the bag is made of a water-permeable material.
4. The method for constructing an anchor body in a soft underground ground according to any one of items 3 to 3.