JP3693613B2 - Protective mat - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a foundation for constructing a breakwater constructed by installing a structure such as a caisson, a landfill revetment such as a waste sea surface disposal site, or a coastal structure that partitions the interior of an artificial island from the open sea. The present invention relates to an asphalt mat used for protection.
[0002]
[Prior art]
When constructing coastal structures such as breakwaters and revetments, perform ground improvement work to strengthen the seabed ground, level the ground surface in the construction area, and then remove large and small crushed stones from the ship. A foundation mound having a predetermined height and width is constructed by dropping and stacking, a top surface of the foundation mound is leveled, and a structure such as a caisson is installed on the foundation. Since the foundation mound is constructed by stacking stones, there are naturally many gaps between the mounds of the mound, and seawater circulates due to the tide being full. In addition, when the submarine ground is sand, etc., there is water flowing between the sand of the submarine ground that supports the foundation mound. Even if the foundation mound is constructed on the ground as described above, the waves are rough. When constructing in the sea area, the seabed supporting the foundation mound may be easily scoured, and there is a problem that a structure such as a caisson cannot be installed in a stable state.
[0003]
As described above, in order to prevent water from flowing through the foundation mound and scouring the foundation ground, over a predetermined range of the surface of the foundation mound and the seabed ground on the inner and outer water surface side of the foundation mound, A perforated mat (also referred to as “mat member” in the following description) is laid as a protective mat. And the construction method which protects the foundation of a structure from scouring by giving a water-impervious treatment between the inside and outside water surfaces partitioned and partitioned by the structure such as the caisson is used. The asphalt mat used for constructing the protective mat is an asphalt mixture having a thickness of about 5 to 10 cm, a width of about 5 m, and a length of about 10 to several tens of meters. An internal reinforcing member is provided and integrated between the layers, and a cargo handling wire is provided around the plate-like member. The protective mat is used to protect the caisson from slipping on the foundation mound, and the coastal structure is constructed as a partition revetment for a waste landfill site. Even in this case, it is used as a water shielding member between the inner and outer water surfaces.
[0004]
When using the protective mat as a water-blocking member, laying a large number of perforated mats without gaps, placing an asphalt mixture at the seam portion of the perforated mats laid adjacently, Water stoppage and adhesion means using rubber asphalt etc. are being constructed. In addition, in order to protect the seabed ground from scouring in rough seas, etc., a number of holes are provided at the tip of the perforated mat, and a mat member having water permeability at the tip is laid. Has been done. In the case of using the perforated mat, water flows through a hole provided in the water passing portion of the tip portion of the perforated mat formed longer than the range that does not have the water permeability of the mat covering the foundation mound and the seabed ground. As a result, the tip of the perforated mat is buried in the sand (ground), and after a predetermined period, the tip of the perforated mat is stabilized in the ground.
[0005]
[Problems to be solved by the invention]
However, even when the perforated mat is used, it is inevitable that the tip of the mat is covered with waves in the sea where the tide is fast and in the sea around the Sea of Japan where the waves during the winter are very rough. There was a risk that the ground would be greatly scoured before the tip of the protective mat was buried and stabilized in the ground. In particular, when the specific gravity of the perforated mat is about 2.3 and the thickness is about 5 cm, when a large number of holes are provided at the free end, the water passage portion in the perforated mat is used. The underwater weight of the water becomes small, and it is easy to cause inconveniences such as being swollen by the influence of waves, and there is a problem that the action of submerging in the ground cannot be exhibited well. Therefore, in addition to applying a treatment such as forming a thick tip portion (water passage portion) provided with holes in the perforated mat, and having a function of resisting waves, a chain or the like having a large specific gravity is used. Countermeasures such as attaching to the tip of the mat are used. And, as mentioned above, by applying the treatment to increase the specific gravity of the tip part and improve the stability, the tip part of the perforated mat sinks into the ground at an early stage in the place where it is actually used. , Exhibits the effect of improving stability.
[0006]
However, when the tip side of the perforated mat is formed thicker than other parts, there are many inconveniences when storing the perforated mats having different thicknesses in a stacked state or when handling the cargo. . Also, when attaching a heavy object such as a chain to the tip of the perforated mat, it is laborious to produce the perforated mat, and it is transported to the construction site after production and constructed using a crane or the like. In doing so, there is a drawback that the work efficiency of laying the perforated mat is not good because heavy objects such as the chain at the end obstruct. Therefore, in the conventional perforated mat, in order to effectively use the protective mat as a more stable ground protection means, the manufacturing process is simplified and stored in a stacked manner as described above. The current situation is that it is required to solve the problem of cases and cargo handling.
[0007]
The present invention can improve the stability of the mat member after construction by holding a hole mold with a large specific gravity integrally and applying a treatment to increase the weight of the tip of the perforated mat in water. It is intended to provide a perforated mat that facilitates.
[0008]
[Means for Solving the Problems]
The present invention lays over a predetermined range from the foundation mound built on the seabed to the foundation ground, increases the coefficient of friction of structures such as caissons, and protects the ground and foundation against water shielding and scouring. Relates to a protective mat.
According to the first aspect of the present invention, when a perforated mat used as the protective mat is manufactured, a steel hole mold having a large specific gravity is predetermined over a predetermined length from the tip end side of the mat. The perforated formwork used as a formwork for forming a hole in the mat is removed from the produced perforated mat. It is used as a weighting member for the mat.
[0009]
According to a second aspect of the present invention, the perforated mat provided integrally with the perforated mat is subjected to a treatment for improving the adhesion with the asphalt mixture on the portion of the perforated frame that contacts the asphalt mixture. The surface of the hole mold frame exposed from the surface is subjected to rust prevention treatment.
According to a third aspect of the present invention, the hole mold provided integrally with the perforated mat includes a reinforcing means for connecting the hole molds together with an internal reinforcing member embedded in the mat member, and the hole mold The reinforcing means for connecting the frames is made of a flexible material having a large specific gravity and is subjected to a treatment for improving the adhesion with the asphalt mixture.
[0010]
The invention according to claim 4 is characterized in that the hole mold is attached with a steel material added to the inside of the hole wall, and the specific gravity of the tip of the perforated mat is increased.
According to a fifth aspect of the present invention, in the perforated mat in which the hole mold is integrally provided in the water passing portion of the mat front end portion and the water permeability is improved through the hole, the perforated mat has a predetermined range including the water passing portion. The means for reinforcing the mat is provided on at least one of the front and back surfaces of the perforated mat.
[0011]
According to a sixth aspect of the present invention, the perforated mat provided with water permeability by the hole mold is provided with a water flow portion using a lightweight material at a portion where the hole mold is not provided, and the water flow portion Is formed integrally with the asphalt mixture of the mat member.
[0012]
With the configuration as described above, it is not necessary to use a removable form when manufacturing the perforated mat, and the manufacturing process of the perforated mat can be shortened. Moreover, since the internal formwork used as the formwork is made of a material having a large specific gravity, it is possible to increase the weight of the perforated part by laying it on the seabed ground in a state where it is embedded. It becomes possible. Further, the mat can be prevented from being affected by the influence of waves and the like, and the subsidence can be formed at an early stage, so that the construction ground of the coastal structure can be protected from scouring. Further, when a weight member is added to the internal mold, it is possible to increase the weight of the perforated part and improve the stability of the perforated part. In addition to the above effects, when forming a water flow part in a part other than the perforated part, the buoyancy from the lower part of the mat can be released, and the stability of the perforated mat can be further improved. It can create an environment that seaweeds nurture.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the protective mat according to the present invention will be described with reference to the illustrated example. As shown in FIG. 1, a general landfill revetment is provided with a ground improvement section 4 in which a construction for improving the ground is applied to a predetermined area where a seawall load acts on the seabed ground 3. On the part 4, the foundation mound 5 is constructed by stacking stones having a size of 10 to 200 kgf / piece to a predetermined height. The upper surface of the foundation mound 5 is leveled and then the caisson 2 is installed thereon. As the caisson 2, a caisson having an arbitrary structure such as a concrete one or a hybrid caisson is used. Then, by placing the caisson on the upper surface of the foundation mound 5 via the friction increasing member 7 such as an asphalt mat, the caisson can be installed on the foundation mound in a stable state. A wave-dissipating block layer or front rubble layer 6 is constructed on the outer sea side of the area partitioned by the caisson 2 so as to cover the base of the caisson 2 at a predetermined height, and the front rubble layer 6 is a slope of the foundation mound 5. It is constructed so as to cover the portion with a predetermined thickness, and a slope corresponding to the slope of the foundation mound 5 of the front rubble layer 6 is provided.
[0014]
The protective mat 7 for covering the surface of the foundation mound 5 to prevent the caisson 2 from slipping is laid as extending from the slope of the foundation mound 5 to the seabed ground 3 to a predetermined length. When the area to be laid as the protective mat is large, a plurality of asphalt mats are connected and used as the protective mat 7. In the protective mat 7, the perforated mat 10 disposed on the submarine ground 3 is configured as a perforated portion 11 having a predetermined length from the tip thereof, and the perforated portion 11 has a predetermined length. A large number of holes 12 that are penetrated are used. And since the perforated part 11 of the perforated mat 10 has water permeability, the lower sand flows along with the water flow caused by the lifting pressure, so that the perforated part 11 is gradually buried in the sand and the subsidence part 11a. And is held in a stable state in the ground.
Therefore, when the tip of the perforated mat 10 is buried in the ground as the subsidence 11a, the tip is not covered by waves or the like, and the seabed ground 3 supporting the foundation mound 5 is largely washed thereafter. It is prevented from being dug.
[0015]
The perforated mat 10 laid down to the surface of the seabed ground 3 of the protective mat is configured as shown in FIG. 2, but the configuration of the perforated mat 10 is the construction of the coastal structure 1 conventionally. It has almost the same structure as the asphalt mat used at the time. The perforated mat 10 is formed by integrating an internal reinforcing member 15 such as a glass cloth between upper and lower layers constructed by an asphalt mixture, and is integrated with a cargo handling wire 17. The end portions 17... Are exposed for a predetermined length, and the eye portions 18 are arranged at both end portions. Further, an end reinforcing member 19 such as an iron plate is embedded in the inside of the asphalt mixture at the base exposed from the perforated mat of the wires 17, so that the wire does not break through the asphalt mixture layer and escape. ing. Then, when the perforated mat 10 is hung by a hanging tool provided on a crane, the both ends of the wires 17 are locked to hooks so that they can be handled stably. .
[0016]
A perforated portion 11 is provided over a predetermined range on the tip end side of the perforated mat 10 that is extended and laid on the seabed ground. As the hole 12 provided in the perforated portion 11, Hereinafter, the case will be described using the internal mold 20, but the hole mold used as a mold at the time of manufacture is used as it is embedded. In addition to embedding and integrating the hole molds, additional reinforcing means as described below are used to securely hold a large number of hole molds inside the asphalt mixture of the mat layer. Yes. As the additional reinforcing means, a perforated portion 11 is buried in the seabed ground by using a member that has a large specific gravity such as a chain and can increase the weight of the tip of the mat member. Be able to assist in the action.
[0017]
In addition, when using a thick steel pipe or the like as the internal mold 20, the surface in contact with the asphalt mixture is coated with asphalt or the like to improve the adhesion with the asphalt mixture and added. For the reinforcing means, the same surface treatment is used. Further, the portion of the internal mold 20 that contacts seawater, that is, the surface that is not bonded to the asphalt mixture is treated with a rust preventive paint or the like, and when the perforated mat is laid in the sea, Processing to prevent corrosion of steel members such as molds.
[0018]
When the perforated mat 10 is produced, the ground for ground production is leveled, and then the mold 25 is assembled to the size of the perforated mat as shown in FIG. A release paper is placed underneath, and a treatment for facilitating peeling of the asphalt mixture to be cast is performed. Then, the inner molds 20... As the hole molds are arranged at predetermined intervals in the interior partitioned by the mold 25, and the asphalt mixture is placed as shown in FIG. First, the lower layer portion 13 corresponding to half the thickness of the mat member is constructed, and the space between the mat body and the inner mold 20 is filled and scraped, and the wire 17 is formed on the surface of the lower layer portion 13. Are arranged at predetermined intervals, and the internal reinforcing member 15 is laid thereon. Further, an additional reinforcing means 22 for connecting the internal molds 20... To each other is arranged on the part corresponding to the perforated part 11, and a large number of internal molds are used by using any connecting means. 20 ... are connected to each other. After arranging the internal reinforcing member 15 and the like on the lower layer portion 13 of the perforated mat, the asphalt mixture of the upper layer portion 14 is cast to prepare the perforated mat 10, and after the predetermined curing period has passed, the formwork When 25 is removed, the perforated mat 10 is created with the inner mold 20... Embedded and held in the perforated part 11.
[0019]
In the perforated mat 10 configured as described above, since the reinforcing means by the internal reinforcing member 15 is embedded inside the mat body, the same resistance to bending as the conventional perforated mat can be exhibited. However, when the perforated portion 11 is greatly bent to form the subsidence portion 11a, a crack may occur in the asphalt layer at the bent portion. Therefore, in order to strengthen and protect the asphalt layer from cracks and the like, as shown in FIG. 4, surface reinforcing layers 16 and 16a are integrated with the asphalt mat body on the upper and lower surfaces of the mat member. It may be formed by bonding. As the surface reinforcing layer, for example, a two-component rubber asphalt is applied at a predetermined thickness to form a reinforcing layer, and a glass cloth impregnated with asphalt or a rubber asphalt impregnated roofing is used. The sheet-like member can be subjected to processing such as sticking with an asphalt adhesive.
[0020]
The surface reinforcing layer may be formed on both the upper and lower surfaces of the mat member. However, when the surface reinforcing layer is formed on at least the upper surface, the resistance to bending action applied to the mat member can be satisfactorily exhibited. The formation of the surface reinforcing layer on the upper surface of the perforated mat 10 can be performed at an arbitrary timing after the construction of the asphalt layer of the perforated mat. In addition, in order to create a reinforcing layer on the lower surface, a sheet-like reinforcing member such as glass cloth or rubber asphalt-impregnated roofing is laid on the ground in the first stage of manufacturing a perforated mat, This can be dealt with by placing an asphalt mixture as a lower layer.
[0021]
When the inner mold 20 is cut from a thick iron pipe and a chain is used as the additional reinforcing means 21, they can be connected and used as shown in FIGS. First, a thick iron pipe is cut into a predetermined length with the same length as the mat member to create an internal mold 20, and then an additional reinforcing means 22 is provided at an intermediate portion in the height direction. The connecting tool 21 for connecting to is attached. As the connection tool 21, for example, a wire or the like may be fixed by welding, but in addition, a ring-shaped or arbitrary-shaped protrusion is fixed by welding and prepared. And after arranging according to a predetermined pattern in the position corresponding to the perforated part of a perforated mat, and constructing the lower layer part of the asphalt layer of a mat, laying of an internal reinforcement member and a wire are arranged, and FIG. The additional reinforcing means 22 is arranged as shown in FIG. 3 and the additional reinforcing means 22 is connected to the connecting tool of the internal mold 20 by the connecting portion 23. In order to connect the internal formwork to the additional reinforcing means, for example, a number wire is tied to a link of the chain, or any other connecting means is used as the connecting means of the connecting portion 23.
[0022]
The example shown in FIG. 8 shows an example in which a weighting means for increasing the weight is provided inside the pipe of the internal mold 20. First, for the internal mold 20 formed by cutting a thick pipe having a predetermined diameter, a connecting member 21 is attached at a predetermined position around the internal mold 20, and a weight member 24 is welded inside the internal mold 20. A heavy object is attached by means such as fixing. As the weight member 24, any material can be used as long as it allows water to flow inside the internal mold 20 and does not prevent the perforated portion from sinking into the seabed ground. For example, a thick iron plate is used after being cut according to the inner diameter of the internal mold, or a thick H, I-type steel or the like cut according to the inner diameter of the internal mold is welded inside the internal mold 20. What is necessary is just to fix using arbitrary means, such as doing.
[0023]
In addition to ensuring water permeability at the perforated portion of the perforated mat and using a means for increasing the weight at the perforated portion, the following auxiliary means may be provided for the perforated mat. Is possible. For example, in places where the water pressure from the ground acts on areas other than the perforated part of the perforated mat through the sea area where the tidal current is fast or gravel, etc., the water pressure that lifts the perforated mat acts greatly from the lower surface. To do. In such a sea area, in addition to the perforated part of the perforated mat, a water permeable part through which the seawater circulates is formed. If provided, the stability after laying the perforated mat can be improved. The perforated mat provided with the water permeable portion can be configured, for example, as shown in FIG. 9, and the perforated mat 10 a is provided with a perforated portion 11 at the distal end portion and the perforated portion 11. As the water permeable portion 30 formed in the predetermined range on the main body side, the water flow portions 31... Are arranged according to a predetermined pattern.
[0024]
In the example shown in FIG. 9, as the water passing portion 31 formed in the perforated mat 10 a, a member having water permeability such as nonwoven fabric but not allowing sand or the like to pass therethrough can be provided as shown in FIG. 10. In the example shown in FIG. 10, when the water-permeable portion 31 is formed using a water-permeable material such as a nonwoven fabric, the lower portion of the mold 32 is disposed corresponding to the lower layer portion 13, and the asphalt in the lower layer of the mat 10 a A layer is constructed, and a water-permeable material 33 is disposed thereon together with the internal reinforcing member 15 and the like, and a peripheral portion of the water-permeable material is attached so as to be sandwiched between upper and lower layers. Next, a formwork corresponding to the upper layer portion 14 is arranged, and the asphalt mixture of the upper layer portion 14 is cast and integrated so as to protect the water-permeable material. The mold can be made of paper or any other material that does not adversely affect the environment, and the mold is not removed after the perforated mat is manufactured. You can use it as it is.
[0025]
Moreover, as the water-permeable material, as shown in FIG. 11, a block-shaped water-permeable material 34 in which a cotton-like member is formed as a block having a predetermined size can be used.
The water-permeable material 34 may be formed as a cylindrical block using a synthetic resin fiber such as polyester, or may be made of a resin material having an arbitrary water permeability and impervious to sand. . Then, a part of the water permeable material 34 is embedded in the asphalt mixture layer and integrated so as not to leave the perforated mat. In addition, when attaching a block such as the water permeable material 34, a means such as passing a wire or the like through the block and fixing the end of the wire between the upper and lower asphalt layers together with the seabed ground is used. It can be easily held so as not to be separated from the hole.
[0026]
As described above, when the water passing portion that has been treated to reduce the lifting pressure is provided in the perforated mat, the fiber material placed in the water passing portion of the perforated mat is easily seaweed or the like. An environment that adheres to the surface can be formed. It is also possible to reduce the lift pressure received by the mat by the water flow part and to reduce the influence of the tidal current received by the mat by covering the surface of the mat with seaweed that grows in the sea area where the perforated mat is laid. become. Furthermore, if seagrass can be grown on the surface of the perforated mat, naturally, fry fish and the like depending on the seagrass are protected, so that the natural environment in the construction area of the coastal structure can be recovered early.
[0027]
As described above, a mold member for forming a hole in the perforated portion of the perforated mat is created using a heavy object, and even after the perforated mat is created, the mold member is attached to the mat. In order to increase the weight, it can be used as an auxiliary member. In addition to using the internal formwork, in order to connect the internal formwork and hold it inside the mat, in the case of using additional reinforcement means, taking into account the weight of the additional reinforcement means, It can be used as means for increasing the weight of the perforated part. Therefore, after laying the perforated mat, it becomes possible to form the subsidence at an early stage, and after constructing the protective mat in the rough sea area, easily stabilize the tip of the perforated mat, The ground can be protected from scouring and the stability of the foundation mound can be guaranteed.
[0028]
When a large number of holes are formed in the perforated part of the perforated mat, assuming that the thickness of the mat is 5 cm, the increase in weight due to the provision of the weighting means is calculated as follows. Come to explain.
"For perforated form only"
(1) Front end mat area A1 (when provided at 1.6 m from the front end)
A1 = 1.6 × 5.5 (m) = 8.8 m²
(2) When formed as a hole area A2 (D = 20 cm),
A2 = (πD²/ 4) x N
= {(3.14 × 0.2²) / 4} × 48 = 1.51m²
[0029]
(3) Mat substantial area A3 provided with a tip hole, and air weight W1
A3 = A1-A2 = 8.8-1.51 = 7.29 m²/Sheet
W1 = A3 × specific gravity of internal formwork (γ1)
= 7.29 x 0.05 m x 2.30 = 0.84 t / sheet
(4) Weight of internal mold: carbon steel specific gravity (γ2) = 7.86, outer diameter 216.3 mm, wall thickness 8.2 mm, inner diameter 199.9 mm, w = 42.1 kg / m The weight of the inner mold having a length of 0.05 m is W2-2.1 kg / piece.
・ Weight of internal formwork Wp = 2.1kg × 48 pieces = 100.8kg
Internal cavity Vp = Wp / γ2 = 100.8 / 7.86
= 12.82 liters = 0.0128m^Three/Sheet
-Underwater weight Wo = 0.0128m of internal formwork^ThreeX (7.86-1.03) = 0.0874t
[0030]
(5) Real underwater weight Wam1 of the perforated part
Wam1 = 7.29m²× 0.05 × (2.3-1.03) = 0.463t
(6) Underwater weight Wamw of mat with internal formwork
・ Wamw = Wam1-Underwater weight of perforated part
= 0.463t-0.0128m^Three(2.3 × 1.03) = 0.447t
Since Wo is 0.0874t,
The underwater weight W of the perforated part is
W = 0.447t + 0.0874t = 0.534t
[0031]
(7) Weight comparison with no internal formwork
Mat without holes (Wam1): Mat with internal formwork (W)
= 0.463: 0.534 = 1: 153
That is, it is 15.3% up.
The above calculation is for a mat with a thickness of 5 cm. For example, when a mat with a thickness of 10 cm is used, the weight increases twice as much as the calculated value, and the stability in water is further increased. It becomes possible to improve.
[0032]
As described above, if the hole provided in the perforated portion with respect to the perforated mat is used with the internal mold attached, the underwater weight in the perforated portion can be increased by 15% or more. In addition to the above structure, when steel material such as a chain is used as an additional reinforcing means to connect the internal formwork, and when a weight member is added inside the internal formwork, it is further perforated. The weight of the part can be increased.
Therefore, the hole mold provided for the perforated part is made of steel, and connection members and weighting members are added to the perforated part. Improve the sinking can be achieved early.
[0033]
When constructing the perforated part with increased weight, the aggregate used for the asphalt mixture is replaced with gravel or other materials, and when iron aggregate ore with high specific gravity is used as the aggregate It is possible to increase the specific gravity of the asphalt mixture. If a thick pipe is used as an internal mold in addition to the asphalt mixture, and a unit having a large unit weight is used as an additional reinforcing means, the weight of the perforated portion can be increased. Therefore, the stability on the seabed after the perforated mat is laid can be improved without forming the thickness of the perforated part larger (thicker) than that of the other part.
[0034]
Furthermore, when manufacturing the perforated mat, a manufacturing method similar to that of a conventional mat member can be applied, and the thickness of the mat can be arbitrarily set according to the wave conditions of the sea area to be constructed. Can be created. In addition, it is possible to use an internal reinforcing member disposed inside the mat and an arrangement relationship such as attachment of a wire for cargo handling in the same manner as a conventional asphalt mat. Further, the length of the perforated part can also be configured according to the conditions of the construction sea area, and conventionally known technical means can be used as means for connecting a large number of asphalt mats in the sea.
[0035]
【The invention's effect】
Since the protective mat of the present invention is configured as described above, it is not necessary to use a removable form when manufacturing the perforated mat, and the manufacturing process of the perforated mat can be shortened. In addition, since the internal formwork as the formwork is made of a material having a large specific gravity, it is possible to increase the weight of the perforated part by laying it on the seabed ground in a state where it is embedded. Become. Further, the mat can be prevented from being affected by the influence of waves and the like, and the subsidence can be formed at an early stage, so that the construction ground of the coastal structure can be protected from scouring. Further, when a weight member is added to the internal mold, it is possible to increase the weight of the perforated part and improve the stability of the perforated part. In addition to the above effects, when forming a water flow portion in a portion other than the perforated portion, the lifting pressure from the lower portion of the mat can be released, and the stability of the perforated mat can be further improved. It can create an environment that seaweeds nurture.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a configuration of a coastal structure.
FIG. 2 is a plan view of a perforated mat.
FIG. 3 is an explanatory view of the arrangement state of the mold when manufacturing the perforated mat.
FIG. 4 is an explanatory diagram of a state of an internal mold provided in a perforated portion.
FIG. 5 is an explanatory diagram of another arrangement state of the internal formwork.
FIG. 6 is an explanatory diagram of a configuration of an internal mold.
FIG. 7 is an explanatory diagram of a relationship between an internal formwork and additional reinforcing means.
FIG. 8 is an explanatory diagram of an example in which a weight member is provided inside the internal mold.
FIG. 9 is an explanatory diagram of an example of another configuration of a perforated mat.
FIG. 10 is an explanatory diagram of an example in which a non-woven fabric layer is provided in a water flow portion.
FIG. 11 is an explanatory diagram of an example in which a block layer is provided in a water flow portion.
[Explanation of symbols]
1 coastal structure, 2 caisson, 3 submarine ground,
4 Ground improvement department, 5 Foundation mound, 6 Masonry department,
7 Asphalt mat, 10 perforated mat, 11 perforated part,
12 holes, 13 lower layer, 14 upper layer,
15 internal reinforcing member, 16 surface reinforcing layer, 17 wire,
20 internal formwork (pipe formwork), 21 connector,
22 additional reinforcing means, 23 connecting member, 24 weighting member,
25 molds, 30 water permeable parts, 31 water flow parts, 32 molds,
33 fiber layers, 34 fiber blocks.

Claims (6)

For the purpose of protection, it is laid from the foundation mound constructed on the seabed ground to the foundation ground to increase the coefficient of friction of structures such as caisson, and protects the ground and foundation against water shielding and scouring Mat,
When manufacturing a perforated mat used as the protective mat, a steel hole mold frame having a large specific gravity is disposed over a predetermined length from the tip end side of the mat through a predetermined arrangement interval, Forming a water flow part of a predetermined thickness by the asphalt mixture,
A protective mat, wherein a hole mold used as a mold for forming a hole in the mat is used as a weighting member of the mat without being removed from the manufactured perforated mat. In the hole mold provided integrally with the perforated mat,
The portion of the hole mold that contacts the asphalt mixture is subjected to a treatment for improving the adhesion with the asphalt mixture,
2. The protective mat according to claim 1, wherein the surface of the perforated form frame exposed from the perforated mat is a rust-proof surface. The hole mold provided integrally with the perforated mat has an internal reinforcing member embedded in the mat member,
Reinforcing means for connecting the hole molds to each other is provided,
The protective means according to claim 1 or 2, wherein the reinforcing means for connecting the hole form is made of a flexible material having a large specific gravity and is subjected to a treatment for improving adhesion to the asphalt mixture. mat. 4. The hole mold according to any one of claims 1 to 3, wherein a steel material is added and attached to the inside of the hole wall, and a process for increasing the specific gravity of the tip of the perforated mat is performed. Protective mat. In the perforated mat that is provided integrally with the water passing portion at the tip of the mat to improve the water permeability through the hole,
The protective mat according to any one of claims 1 to 4, wherein means for reinforcing the mat is provided on at least one of the front and back surfaces of the perforated mat within a predetermined range including the water flow portion. In the perforated mat with water permeability by the hole mold,
6. A water passage portion using a lightweight material is provided in a portion where the hole mold is not provided, and the water passage portion is formed integrally with an asphalt mixture of a mat member. Protective mat according to crab.

Images