JPH08269929A - Protecting construction method for submarine buried object - Google Patents

Abstract

PURPOSE: To protect nature in the sea by arranging a protecting mat member so as to cover the upper part of the back filling earth, and forming environment where a sea weed can grow on the surface of the protecting mat member in the case where an accommodating groove is excavated on a sea bottom ground to execute a buried object, preventing the occurrence of the scouring of back filling earth. CONSTITUTION: An accommodating groove 2 having a fixed depth is excavated on a sea bottom ground 1, and a pipe line and other buried objects 3 are executed, and back filling earth 4 is executed in the accommodating groove 2 to make its height the same as the sea bottom surface. A protecting mat member 10 is arranged on the surface of the back filling earth 4 to composite a means for preventing the scouring of the back filling earth 4, and the protecting mat member 10 is composed as a member formed by laminating a base mat member and an elastic body layer. A material suitable to adhering and growth of a sea weed such as a natural fiber or iron is arranged on the surface of the protecting mat member 1 to newly form the growing environment of the sea weed or the like on the surface of the protecting mat member 10 for facilitating to give good influence to fishing industry.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of protecting buried objects by excavating and burying a seabed ground, and in particular, a protective mat member is laid on the upper surface of the backfilled soil to protect the buried object, The present invention relates to a method for protecting an undersea buried object, which can prevent scouring due to waves and the like and can easily propagate seaweed and the like on the surface of the protective mat member.

[0002]

2. Description of the Related Art A long buried object to be laid on the seabed such as a pipeline, an electric wire, a telephone line, etc. has a housing groove 2 in a seabed 1 as shown in FIG. It is constructed by excavating to a depth, arranging the buried object 3, and applying backfill soil 4 on the upper part of the buried object 3. The thickness H of the backfill soil 4 to be applied on the buried object 3 is 3 to 4 m so that the buried object can be protected against the impact when the anchor of the ship falls. ing. When burying the above-mentioned buried object in the seabed, by excavating the storage groove, laying the buried object, and constructing the backfill soil in parallel, the construction sea area becomes cloudy and the fishing industry Consideration such as shortening the period that affects

However, since the backfill soil for protecting the above-mentioned buried matter uses the earth and sand collected in other sea areas and the earth and sand excavated in the storage ditch, it is washed by the influence of the ocean current. There is. And as shown in FIG. 7, a scour part 5 may be formed in the upper part of the backfill soil 4, and the thickness of the backfill soil that protects the buried object becomes H1, and the anchor of the ship is The impact of falling is directly transmitted to the buried object, and the problem that the buried object cannot be protected by the backfill soil is likely to occur. As the scouring progresses further, the layer of backfill soil becomes thinner, and the force that pushes the buoyancy of the backfill soil by the backfill soil decreases, and there is a problem such as exposure to the seabed surface with a relatively light backfill, If the ship drags on the anchor, the buried object may be damaged.

Therefore, as described above, in order to prevent the scour portion from being formed in the backfilled soil, the state of the seabed ground is monitored at any time, and soil or the like is collected at the place where the scour portion occurs. It is also possible to discard and keep the thickness of backfill soil constant.
One way. However, if the sea area where the buried object is laid is a good fishing ground, performing work such as dumping sediment into the sea area may cause turbidity in the sea area near the sea area, which may greatly affect the fishing industry. Therefore, there is a problem that it is not possible to obtain the approval of the fishery association. further,
One method is to throw a large stone such as crushed stone against the area where the scour is formed, and use a means to counteract the scour, but the impact of dumping a large stone adversely affects the buried object. However, it is difficult to find a solution to the problem of scouring of backfill soil.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problem of protecting a seabed laying, and prevents a scour portion from being formed by laying a protective mat member on top of backfill soil. At the same time, it is an object of the present invention to provide a method for protecting a submarine buried object in which seagrass or the like is easily attached to the surface of the protective mat member and propagated, thereby improving the environment of the seabed.

[0006]

The present invention relates to a method of excavating a storage groove having a predetermined depth in a seabed, laying a buried object on the bottom of the storage groove, and then applying backfill soil. In the present invention, a protective mat member is laid on the surface of the backfilled soil, and the protective matte member is a seaweed, a surface layer subjected to a treatment that allows microorganisms in the sea to easily attach, and the backfilled soil is protected by pressing. And a base layer having a certain weight are integrally formed, and the surface of the backfill soil can be protected by the protective mat member. Further, in the present invention, an elastic layer in which a material to which seaweed is easily attached, such as a natural fiber, a woven cloth, an iron plate or a wire is exposed, and a base layer having high strength are integrally formed in the surface layer. Alternatively, the surface of the backfilled soil can be protected by the protective mat member. Further, in the present invention, the base layer of the protective mat member is constituted by an asphalt mat, and the wire or reinforcing member arranged inside the asphalt mat and the elastic layer constituting the surface layer are formed by using a wire. It can be configured by being integrally connected.

[0007]

As described above, in the protection method of the present invention, when the buried object is laid, the protection mat member is laid on the top of the backfilled soil so that the backfilled soil and the like are discarded. Since the protective mat member is placed on the soil, it is possible to prevent scouring of the backfill soil. Also, when the main body of the protective mat member is made of a material having a large specific gravity such as asphalt mat, both ends will naturally sneak from the surface of the seabed, and the protective mat member causes scouring of the backfilled soil. Can be prevented. The protective mat member allows the protective mat member to receive the impact of the drop of the anchor, and it is possible to prevent an excessive impact from being applied to the embedded object, and also for the relatively lightweight embedded object, It is possible to exert a pressing action, and it is possible to maintain the protective action for the buried object for a long period of time.

Further, the protective mat member of the present invention has an elastic layer on the surface of which a material such as natural fiber, woven cloth, iron plate or wire to which seaweed is easily attached is exposed. Therefore, when the protective mat member is laid on the seabed, seagrass, marine microorganisms and the like can be easily attached and propagated, and the environment of the seabed can be favorably maintained.
Further, since the surface layer of the protective mat member is configured as an elastic body, it is possible to mitigate the impact and the like when the anchor is dropped, and prevent the buried object from being adversely affected. In addition to the above action, in the protective mat member of the present invention, it is also possible to lay the elastic layer of the protective mat member facing downward, and by having the base layer having a large strength located above, It is possible to mitigate the effect of the impact of the dropping of the anchor by the lower elastic body layer and prevent the surface of the protective mat member from being caught. By forming a layer to which seaweed easily adheres on the base layer as the surface layer of the protective mat member, the natural environment of the seabed can be maintained in a good state.

[0009]

EXAMPLE A method for protecting a submarine buried object according to the present invention will be described with reference to the illustrated example. The example shown in FIG. 1 shows the concept of a method for protecting a submarine buried object according to the present invention. Construction of 3 and protection with backfill soil 4 is carried out in the same manner as in the case of the conventional construction method. In the present invention, the protective mat member 10 is spread over the portion corresponding to the upper portion of the backfill soil 4 and the construction is carried out. The unit member of the protective mat member, which is formed to be slightly wider than the width, is arranged as a protective member by arranging so that there is no gap between the respective connecting portions. Then, when the anchor 7 of the ship is dropped, the impact of the anchor is received by the protective mat member 10 to prevent a large impact from being applied to the layer of backfill soil 4 and the buried object 3. , Means for preventing scouring of backfilled soil due to the influence of tidal current.

As described above, when the protective mat member 10 is placed on the backfill soil 4, the protective mat member 1
Due to the large weight of 0 and the elasticity of the protective mat member, the end 11 of the protective mat member may sink from the surface of the seabed due to the influence of tidal currents and waves as shown in FIG. Be affected. Then, since the protective mat member 10 stabilizes in a state of covering the backfilled soil portion above the accommodation groove 2 in a relatively short period after the construction of the protective mat member, the protective mat member 10 is buried due to the influence of tidal current or waves. It is possible to prevent scouring on the backfill soil. Therefore, by covering the backfill soil 4 constructed by throwing earth and sand or the like into the storage groove with the protective mat member 10,
The thickness of the backfill soil can be maintained constant, and the function of protecting the buried object by the protective mat member and the backfill soil can be exhibited in a good state.

As described above, the protective mat member 10 disposed on the backfill soil is constructed as shown in the sectional view of FIG. 3, and the base mat member 12 is constructed of asphalt mat or the like. The wire 13 and the like are embedded and provided inside the asphalt mat. The base mat member 12 composed of the asphalt mat is molded in two layers in the same manner as in the production of a conventional asphalt mat. After the lower layer 12a is applied to a predetermined thickness, the glass fiber is formed. A reinforcing member such as a net-shaped member or a wire mesh formed of the like and a wire 13 for lifting are arranged. The wire can be used when hoisting with a crane or the like by providing the eye parts exposed from both ends of the protective mat member, and also when connecting adjacent protective mat members. , The ends of the wires can be connected. Then, an asphalt mastic having a predetermined thickness is applied to the upper portion of the reinforcing layer to form an upper layer 12b, and the upper and lower layers 12a and 12b are bonded to each other by using an asphalt component, and the reinforcing member is internally provided. It can be configured as an integrally provided mat.

On the upper surface of the base mat member 12 constructed as described above, an elastic body layer 15 having an arbitrary thickness is arranged with an adhesive layer 14 interposed between the base mat member 12 and the elastic body layer 15. The protection mat member 10 provided integrally is configured.
In addition, when the base mat member 12 is formed, a large number of connecting members such as the wires 18 are attached to the wire 13 and the reinforcing member disposed inside the mat at predetermined intervals, and the end portions of the wire 18 are matted. It is provided so as to largely project from the surface of the layer above. Then, when the elastic body layer 15 is attached to the surface of the upper layer of the base mat member 12 via the adhesive layer 14, the wire 18 is extended to the upper surface of the elastic body layer 15 and the elastic body layer 15 is formed. Connect the wire on the upper surface of and fix it.

The elastic layer 15 integrally arranged with the base mat member 12 is formed by laminating, for example, a natural fiber member such as cotton or hemp, and a woven fabric, or
It can be constituted by the non-woven fiber layer 16 using a natural fiber member. In addition, a felt-like material composed of any natural material can be used, and by using such a natural material, seagrass and marine microorganisms can easily attach to the roots and propagate inside. Configure an environment like this. A relatively net-like net member 17 is arranged on the upper surface of the non-woven fiber layer 16 to cause the net member 17 to press and hold the fibers of the non-woven fiber layer 16. . Further, when the base mat member 12 and the elastic layer 15 are integrated with each other by the wire 18, in addition to simply twisting and binding the part of the wire 18 projecting above the net member 17, It is also possible to use a means for binding the wires 18 via an iron rod 19 or the like.

In the protective mat member 10 of FIG. 3, the elastic layer 15 is integrally arranged on the upper surface of the base mat member 12 with a predetermined thickness, and the base mat member 12 is constructed as a member having high strength. By doing so, it is possible to deal with the impact when the anchor is dropped from the ship, the impact when the heavy object falls, and the like. Further, since the elastic body layer 15 is arranged on the upper surface of the base mat member 12, when a heavy object such as an anchor falls, the impact of the base mat member due to the elasticity of the elastic body layer can be alleviated. It is possible to reduce the impact directly applied to the base mat member. Then, by placing the protective mat member 10 formed as a composite mat on the backfill soil 4, it is possible to prevent the impact from being transmitted to the buried subject through the backfill soil, and to protect the buried article safely. can do.

In addition to the above-mentioned protective action against the buried object, the protective mat member 10 of the present invention constitutes an environment in which seagrass adheres to the upper surface of the base mat member 12 to grow. That is, since the elastic layer 15 is composed of natural fibers, the spores of seaweed are non-woven fiber layers 1.
It adheres to the surface of No. 6 and forms an environment where it can grow naturally, and provides an environment in which microorganisms in the sea can enter the inside of the elastic layer and organisms in the sea can lay eggs. Then, even when the storage trench is excavated in the sand and the buried object is buried, a band-shaped layer of a fiber having a different property from the sand is formed on the seabed at a portion where the buried object is constructed, so that the sand It is possible to provide a new growth environment for marine organisms such as seaweeds and fishes in the environment of slaughter. Therefore, as compared with the case of the conventional method for burying buried objects, when the method for covering backfill soil with the protective mat member of the present invention is used, a new growth environment can be provided for marine organisms. Therefore, the natural undersea environment can be formed as a more effective one.

The asphalt mat constituting the protective mat member does not have a harmful asphalt component to the natural environment and does not become an obstacle when weeds extend their roots through a gap as seen in road pavement. It is known that when it is constructed in the sea, it does not hinder the growth of seagrass. Even when a protective mat member is used as the backfill soil coating material of the present invention, the asphalt component forming the base mat member has no effect on the action of marine organisms adhering to and multiplying the elastic layer. It does not give. However, when the asphalt component is exposed, spores such as seaweed cannot adhere. Therefore, in the present invention, by providing a member, such as natural fiber, which has a good effect on living organisms in the sea, on the surface, it is possible to prevent disturbing the natural environment in the sea and create a new natural environment. To be able to.

As shown in FIG. 3, the protective mat member 1
In addition to forming the elastic layer 15 on the surface of No. 0 and arranging the base mat member 12 having high strength under the elastic layer 15, a protective mat member 10a as shown in FIG. You can also do it. The protective mat member 10a of FIG. 4 is constructed by reversing the protective mat member 10 of FIG. 3, in which the base mat member 12 is arranged on the upper surface and the elastic layer 15 is arranged on the lower surface. The non-woven fiber layer 16 and the net member 17 constituting the elastic layer 15 are integrally connected to the base mat member 12 by the adhesive layer 14 and the wire 18. Further, a groove 20 having a groove shape or an arbitrary shape is formed on the surface of the base mat member 12 configured as an upper layer at a predetermined interval, and a natural fiber such as a fiber layer 21 such as felt is formed in the groove 20. The member composed of is attached. And the fiber layer 21
By arranging on the surface of the asphalt mat, it is possible to form an environment in which sea life grows on the sea floor. Further, the fiber layer arranged on the surface of the base mat member can be attached to the groove using any adhesive component, and the adhesive component is naturally harmless. .

The protective mat member 10a shown in FIG.
When using as a protection member for backfill soil, the base mat member 12 arranged on the surface is subjected to impact such as dropping an anchor, but may be damaged even if impact is applied due to the strength of the base mat member. There is no. Since the impact applied to the base mat member is mitigated by the elastic layer 15, the impact is not transmitted to the buried object through the backfill soil, and the buried object can be safely protected. it can. Further, since the fiber layer 21 made of natural fibers is integrally provided on the surface portion of the protective mat member exposed to the seabed, seagrass or the like can adhere to the fiber layer to grow.

Further, in the present invention, a protective mat member 10b as shown in FIG. 5 can be constructed and used as a protective member for backfill soil. The protective mat member 10
b is a base mat member 12 arranged on the upper surface and an elastic layer 1 arranged on the lower surface, similar to the protective mat member of FIG.
5 are integrally connected to each other through the adhesive layer 14 and the wire 18. Further, in the base mat member 12 arranged on the upper surface of the protective mat member 10b, a large number of concave grooves 20 ... Are arranged at arbitrary intervals with respect to the exposed surface thereof, and a fiber layer 21 made of natural fibers or the like. Is installed in the groove. The fiber layer 21 is a wire 1 to be arranged on the base mat member 12.
3, a wire 23 can be connected and fixed, and like the wire 18 to which the elastic layer is attached,
The fiber layer 21 is integrally fixed and held on the surface of the base mat member with the wire penetrating the fiber layer 21 or by using any fixing means.

In the protective mat member 10b, an iron-containing layer 22 having iron protrusions arranged on one surface is provided on the exposed surface of the base mat member 12 so that it does not adhere to the asphalt mat, but it does not adhere to the iron content. Care is taken to attach seagrass. In order to form the iron-containing layer 22, it is possible to use a means for applying an asphalt mastic on a short wire or a small piece of scrap iron or the like, and adhering and holding the iron content to the asphalt mat by the asphalt component. The iron-containing layer 22 can also be configured by integrally disposing a wire mesh or the like on the exposed surface of the base mat member, and in order to hold the wire mesh on the exposed surface of the base mat member 12, the wire 23 is used. It is also possible to use a means for fixing using. Further, in the concave groove 20 arranged on the exposed surface of the base mat member, a member in which the fiber layer 21 is integrally covered with the metal net 24 is arranged, and a composite of iron and fiber can be provided.

As shown in FIG. 5, the iron component is arranged on the surface of the protective mat member because it is known that seaweed adheres to iron and grows. Further, in the backfill soil protection member of the present invention, by arranging iron and fiber on the surface of the asphalt mat in a composite manner, it is possible to provide an environment in which a plurality of types of seaweed can grow on the surface of the protection mat member. be able to. Therefore, in the protection mat member, a protection mat member is constructed as a protection member against scouring of backfilled soil to protect buried objects, and the protection mat member creates a new growth environment for seaweeds and the like. It becomes possible to form a growth environment for seagrass on the seabed and the organisms associated with the seagrass.

As described above, the protective mat member 1 is provided after the backfill soil is applied to the storage groove in which the buried object is laid.
When 0 is applied to the upper surface of the backfill soil, a protective mat member having a width capable of covering the backfill soil and having an arbitrary length is closely arranged in the length direction of the accommodation groove. be able to. And when constructing the protective mat member, it suffices to lay the protective mat member manufactured on land sequentially on the backfill soil using a crane ship or the like, and to easily construct the protective mat member. You can In addition, when replacing the protective mat member or when redoing the construction of the buried object, it is possible to easily remove the protective mat member using a crane, and the protective mat member is dragged by the anchor and backfilled. Even if the soil moves out of the protected position, the repair work can be easily performed. Furthermore, when another material suitable for growing seaweed is to be attached to the surface of the protective mat member, a fixing member such as wire is exposed on the surface of the protective mat member and the wire is used to separate the fixing member. It is also possible to arbitrarily arrange the fiber member and the like.

The protective mat member of the present invention has been described by taking the case where the base mat member 12 is made of an asphalt mat, but the base mat member 12 may be a rubber mat, for example. Therefore, when the specific gravity of the rubber is small, an iron member or the like having a large specific gravity can be inserted between the two layers of rubber. In addition, it is possible to use any other mat member as long as it can exhibit good weight and impact resistance. Further, in the elastic body layer that is integrally arranged with the base mat member, a very large amount of water has entered inside the non-woven fiber layer, so the impact when the anchor or the like falls is included in the elastic body layer. It will also be relaxed by water. Also in the protective mat member shown in FIG. 3, a metal piece such as iron is attached to the fiber layer arranged on the upper surface, or a wire mesh is arranged on the surface of the net member and integrally fixed by wire. The means can be used to improve the durability of the elastic layer or to configure the environment against seaweed.

[0024]

Since the method for protecting a seabed buried object according to the present invention uses the protective mat member constructed as described above, when the buried object is laid, a protective mat is placed on the backfill soil. Since the protection mat member is placed on the backfilled soil in which the earth and sand have been discarded, it is possible to prevent scour on the backfilled soil by laying the members and performing the construction. Also, when the main body of the protective mat member is made of a material having a large specific gravity such as asphalt mat, both ends will naturally sneak from the surface of the seabed, and the protective mat member causes scouring of the backfilled soil. Can be prevented. The protective mat member allows the protective mat member to receive the impact of the drop of the anchor, and it is possible to prevent an excessive impact from being applied to the embedded object, and also for the relatively lightweight embedded object, It is possible to exert a pressing action, and it is possible to maintain the protective action for the buried object for a long period of time. Furthermore, the protective mat member used in the present invention is
It can be easily moved, and even when the protective mat member is removed, the work can be easily performed using a crane ship or the like.

In addition to the above-mentioned effects, the protective mat member of the present invention has an elastic body for exposing and holding a material to which seaweed is easily attached, such as natural fiber, woven fabric, iron plate or wire on its surface. Since a layer is formed, when the protective mat member is laid on the seabed, seagrass easily attaches and propagates.
In addition, it is possible to create an environment in which marine microorganisms can reproduce, and it is possible to maintain an excellent environment of the seabed. Further, since the surface layer of the protective mat member is configured as an elastic body, it is possible to mitigate the impact and the like when the anchor is dropped, and prevent the buried object from being adversely affected. In addition to the above action, in the protective mat member of the present invention, it is also possible to lay the elastic layer of the protective mat member facing downward, and by having the base layer having a large strength located above, It is possible to mitigate the effect of the impact of the dropping of the anchor by the lower elastic body layer and prevent the surface of the protective mat member from being caught. By forming a layer to which seaweed easily adheres on the base layer as the surface layer of the protective mat member, the natural environment of the seabed can be maintained in a good state.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a construction state of a protective mat member of the present invention.

FIG. 2 is an explanatory view showing a state in which an end portion of the protective mat member is stable.

FIG. 3 is an explanatory diagram showing a configuration of a protective mat member of the present invention.

FIG. 4 is an explanatory view showing another embodiment of the protective mat member of the present invention.

FIG. 5 is an explanatory view showing another embodiment of the protective mat member of the present invention.

FIG. 6 is an explanatory diagram of a conventional buried object protection structure.

FIG. 7 is an explanatory diagram of a state in which scour has occurred in the backfill soil.

[Explanation of symbols]

1 submarine ground, 2 storage trenches, 3 buried objects,
4 backfill soil, 10 protective mat members, 12
Base mat member, 15 elastic layer, 16 non-woven fiber layer, 17 net member, 20 groove, 21
Fiber layer, 22 iron-containing layer, 24 wire mesh.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takaki Waki 1-29-4 Tsurugamine, Asahi-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Mitsuru Nonoda 2-chome, Tamagawa, Ota-ku, Tokyo 11 No. 20 Japan Road Co., Ltd. (72) Inventor Mitsuhiro Sato 3-13-1, Kyobashi, Chuo-ku, Tokyo Yuraku Building Taisei Rotec Co., Ltd. (72) Inventor Katsuo Matsuzaki 2-10 Akasaka, Minato-ku, Tokyo No. 9 Sea of Japan Construction Co., Ltd.

Claims (3)

[Claims] 1. A method of constructing a backfill soil by excavating a storage trench having a predetermined depth in the seabed ground, laying an embedded object at the bottom of the storage trench, and then constructing a backfill soil on the surface of the backfill soil. Along with laying the members, the protective mat member is a seaweed, a surface layer that has been subjected to a treatment capable of attaching marine microorganisms, and a member that is integrated by stacking a base layer that protects the backfill soil by pressing. A method of protecting a submarine buried object, characterized in that the surface of backfilled soil is protected by the protective mat member. 2. An elastic body layer exposing a surface layer of the protective mat member, such as a natural fiber, a woven cloth, an iron plate or a wire, to which sea grass or a material to which microorganisms in the sea easily attach is exposed, The method for protecting a submarine buried object according to claim 1, wherein the surface of the backfilled soil is protected by the protective mat member, which is configured by integrally mounting a large base layer. 3. A base layer of the protective mat member is formed of asphalt mat, and a wire or a reinforcing member arranged inside the asphalt mat and an elastic layer forming a surface layer are integrally formed by using a wire. The construction method for protecting a submarine buried object according to claim 1 or 2, wherein the method is a connection construction.