JP2000144679A - Revetment construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a revetment construction method which purifies water quality and grows plants. SOLUTION: This revetment construction method is constituted of a three- layer structure. Net bag bodies 1 containing natural stones in net bags are installed on the ground surface as a first layer, and net bag bodies 2 containing porous ceramic lumps in net bags are stacked on the first layer to form a second layer. The second layer is covered with clinker ash or soil mixed with clinker ash to form a third layer for planting plants.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to river shores, coasts, lake shores,
The bank protection method to protect the embankment.

[0002]

[Prior Art] Japan has a lot of rainfall and topographically rivers are steep and floods are huge, so the revetment is an anti-natural type of river. It has been regarded as an effective flood control measure to create a straight river like a waterway in an efficient way. Such anti-natural rivers have poor natural purification ability, the water quality of rivers and lakes has gradually deteriorated, and the living environment has been destroyed, and the organisms living in the clear watershed have disappeared. On the other hand, when an underwater structure is installed in the seabed, the structure becomes a tidal resistor, causing eddy currents, the undersea ground surrounding the structure is cut off, and the structure collapses, a phenomenon called scouring. It is well known that this occurs. In addition, scouring phenomena are also observed on the piers of river bridges, and similar phenomena occur on the ground erosion of coasts, river embankments and underwater structures. Conventionally, to prevent such scouring, measures to install a gabion filled with pebbles or crushed stones at the bottom near the underwater structure, cast a large amount of concrete, or increase the burial depth of the structure Has been taken. For the revetment, concrete placement and wave-dissipating blocks such as tetrapots have been used. However, the ground where these underwater structures are installed still suffers scouring. In the gabion, the pebbles in the basket do not flow out, but they do not fit well with the shape of the installation ground, and scouring occurs at the installation part of the gabion.

[0003]

The purpose of revetment is to protect coasts, river banks, lake shores and dikes to protect them from floods and to protect the natural environment. The present invention provides a seawall protection method that protects natural shores and embankments and protects the natural environment by purifying water quality and breeding plants in addition to protecting against flood damage.

[0004]

Means for Solving the Problems The present invention relates to a seawall construction method having a three-layer structure, in which a first layer is provided with a net bag body made of natural stone in a net bag on the ground surface. The second layer is formed by stacking a net bag formed by placing a porous ceramic mass in a net bag, forming a second layer, covering the second layer with clinker ash or soil mixed with clinker ash, and planting a plant. Seawall construction method by laminating layers 2. Porosity of interconnected pores in which the ceramic mass constituting the second layer is a mixed fired product of clinker ash and a viscous mineral and has a water absorption of 10% or more. 2. The seawall construction method according to item 1, which is a ceramic 3. The mesh bag is knitted or knot-knitted with synthetic fiber yarn, has a porosity of 45% or more, an elongation of 15% or more, and the length L of one side of the mesh. Between the natural stone or the diameter D of the porous ceramic body

[0005]

(Equation 2)

The revetment method according to paragraph 1 or 2, which is a net bag formed by a netting satisfying the above relationship. 4. 3. The revetment method according to item 3, wherein the net bag is formed by Russell knitting. 5. 5. The third layer according to any one of items 1 to 4, wherein the third layer is formed of a net bag body by putting clinker ash or soil mixed with clinker ash into a small inner bag of mesh arranged in the net bag. Seawall construction method. About.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention comprises a first layer in which natural stone is placed in a mesh bag, a second layer in which a porous ceramic mass is placed in a mesh bag,
The third planting was carried out by putting a mixed soil of clinker ash and clinker ash in a bag having a composite structure of a mesh bag and a woven bag and planting the plant.
This is a seawall construction method consisting of layers, which improve water quality by combining the water purification function of the porous ceramic mass and the water purification mechanism by growing plants, thereby improving the environment and building a safe seawall. is there.

The third layer is a layer for planting plants. Clinker ash or clinker ash-mixed soil may be laminated as it is, but it is preferable to use the third layer by placing it in a small mesh inner bag arranged in a mesh bag. It is preferable to use biodegradable synthetic fibers for net and inner bags, but in places where river flooding is likely to occur, it is better to use synthetic fibers that are not biodegradable for both net and inner bags. It is preferred. Further, in a place where the flow is gentle, a net bag may be used only at the water's edge, and without the net bag, the third layer may be clinker ash or clinker ash and a mixed soil such as soil generated at the construction site and humus soil up to the glue ass. . What is necessary is just to use the structure of a 3rd layer properly according to the environment of a construction place.

For the first layer, natural stone is packed in a net bag and placed and stacked. This is the foundation of the revetment. The size of the natural stone is from a fist size to a human head size, but a cobble stone shape is particularly preferable. It does not specify. Since the water flows through the natural stone filled in the net bag and the gap between the stones, the flow resistance is small, and the first layer is not washed away by the water pressure.
The stone is held by the mesh bag and does not flow out, so scouring is prevented. In addition, the gap between the stones serves as a dwelling place for aquatic organisms such as fish, and the first-layer net bag and the stones serve as a breeding ground for aquatic plants and seaweeds. Second
The layer is a layer that helps water purification and plant growth. The porous ceramic mass is packed in a net bag and laminated on the natural stone of the first layer, the base layer. This second layer is the midway point between the water and the ground, and corresponds to the waterline part when compared to a ship. The porous ceramic mass purifies water by pores that maintain a water absorption rate of 10% or more, and supplies water to plants on the ground by capillary action.・ We work for upbringing. If the water absorption rate is 10% or less, the supply of water and nutrients becomes insufficient, so that there is no effect. The third layer is a layer in which plants are planted on a porous ceramic layer on clinker ash or a mixture of clinker ash, construction site generated soil and mulch, and the like. Reeds and reeds are perennials and are the most suitable plants. Reeds and reeds develop roots as they grow and extend the roots up to the second porous ceramic layer to help purify water,
Stabilize. In this way, the three layers that function differently from each other constitute a revetment together with the original purpose of the revetment, contribute to the cultivation of plants on the ground, create a green environment, and purify the water. This is a revetment method that promotes the growth of underwater organisms such as fish.

[0010] The porous ceramic mass used in the second layer is a brick-shaped mass having no corners, which is obtained by firing clinker ash and having a water absorption of 10% or more. The clinker ash used for the third layer is, for example, a sand-shaped material mainly composed of silica and alumina obtained by burning coal in a thermal power plant. Clinker ash can also be used as a mixture with the soil generated at the construction site and mulch, but the mixing ratio is preferably 4: 5: 1.

The mesh bag used in the present invention is a mesh bag made of natural fibers and synthetic fibers and has a porosity of 45% or more. Water penetrates into the net bag body, and the net bag body is filled with natural stone having a specific gravity of 1 or more by a weight against the water pressure of flowing water, so that the net bag body can be rapidly deposited on the target water bottom. Further, since the water easily passes through a large void portion of 45% or more of the mesh bag, the water flow resistance is remarkably reduced and the water does not flow from a predetermined position. In addition, since the net of the first layer has an elongation of 15% or more, the shape is freely deformed according to the topography, the structure, etc., so that it is in close contact with the seabed riverbed and the shore or the embankment. Even if a plurality of the first layers are deposited, the bags adhere to each other and can cover all necessary portions.

As described above, the netting constituting the first layer, the second layer and the third layer in the present invention is characterized by having an elongation of 15% or more. It is preferred to use. In the case of Russell netting, it is possible to arbitrarily design the elongation from about 10% to about 100% on the structure of the net. Preferably it is about 15% to 80%. The shape of the Russell netting is rhombic, turtle-shaped, square, and the like. Conventionally, the net has a single mesh foot.
The same purpose can be constituted even if it is constituted by a double net foot consisting of a book. Of course, the strength of the netting may be such that the netting does not break when the weight of the natural stone or the ceramic mass is hung. Further, when the porosity of the netting is 45% or more, the water conveyance coefficient is low, and it can sufficiently cope with the speed of natural water flow. Both knotted nets and knotless nets can be used.

Further, the distance between the diameter (D) of the lump having a specific gravity of 1.00 or more to be filled in the bag and the length (L) of one side of the mesh forming the bag.

[0014]

(Equation 3)

According to the above relationship, in any case, the filled natural stone or ceramic mass does not flow out of the mesh. This relational expression represents a condition for preventing the filled natural stone or ceramic lump obtained from the repeated experiment from escaping from the net, and 1.8 is a safety factor. If a net that satisfies this equation is used, the filled natural stone or ceramic mass does not escape even at a high water flow, a large sinking depth, or at the bottom of various changed shapes. In addition, if the diameter of the inner layer portion, that is, the bottom of the water, is large, the flowing water energy is large if the natural stone or the ceramic mass filled in the first layer and the second layer in the surface layer portion in contact with the water flow is large. Since the water is sequentially dispersed, the energy of flowing water at the bottom of the water can be reduced. As described above, since the present invention is a scouring prevention material that is easy to handle and produce, it can be performed quickly and with low labor and cost in construction work, and an effect that cannot be predicted by the prior art is obtained.

The lower limit of the size of the net bag is such that the net bag contains a mass that can withstand the flowing water pressure, and the upper limit is sufficient if the strength of the net bag can hold the packed mass. And workability. The material of the mesh bag is made of synthetic fibers such as polyester, polyamide, aromatic polyamide, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, polylactic acid, etc., or natural fibers such as cotton and hemp. Any of fibers may be used. The first and second layers of the mesh bag body have excellent elasticity, strength, and abrasion resistance, and can satisfy the object of the present invention.

[0017]

[Example] Manufacture of porous ceramic The porous ceramic constituting the second layer of the seawall construction method is a sintered ceramic with many continuous pores and high water absorption. This is Clinker Ash. Clinker ash is used for roadbed materials, golf courses and the like, but there are few uses of fine grains of 2 mm or less. Clinker ash particle size is also 2.0 to 0.07
The range of mm is 60 to 70%, and these fine particles are also excellent in water purification and plant growth experiments, and are suitable as the main raw material of the second layer. As an example of the production, 60% of clinker ash by weight ratio and 40% of quarry waste mud
%, A raw material of sewage sludge as a raw material for pores, and 50 kg of a blended raw material of 12% in outer ratio were mixed and added with a mixing and adding machine, and then a lump of 50 to 10 mm was formed through a clay molding machine. After drying, a porous ceramic mass was placed in a fireproof container and baked at 1150 ° C. The water absorption of the ceramic for 60 minutes is 17
%, Pressure resistance (50 mm chunk) was 320 kg.

Example 1 Manufacture of a mesh bag body A Russell knitted fabric made of nylon fiber, using a mesh of 25 mm, cutting it into 4 mx 3 m, and stacking two sheets of 2 mx 3
Fold it in two so that it becomes m. The remaining two sides are stitched while leaving the side opposite to the folded part as an opening, and a 9 mm-thick hanging rope is inserted into the mesh from the periphery of the opening of the double-meshed mesh bag, and suspended. A 6-mm-thick squeezing rope is disposed below the second eye of the rope.
80 net bags are manufactured. Manufacture of the first-layer mesh bag body Place the mesh bag in the measuring box along the inside of the measuring box, expand the opening of the mesh bag, fill it with about 2 tons of natural stone with a grain size of around 150 mm, and open the mesh bag. Close the section. The hanging rope is pulled out evenly from the upper mesh of the mesh bag from six places, and the six places are lifted up by hooks of heavy equipment and lifted to such an extent that the filling in the mesh bag body becomes familiar, and lowered when the shape becomes stable. At the same time, tie it to the suspension ring at six places on the suspension rope with a lark. Hook the suspension ring and suspend it temporarily, stop with the opening of the mesh bag in the drawstring state, wrap it around the lower part of the hanging rope of the drawstring portion of the mesh bag with a mouth drawing rope, tie the opening, The remaining tying ropes are wound around six hanging ropes coming out of the opening of the mesh bag and bound so that the hanging ropes do not fall apart, and the natural stone-filled mesh bag body 1 of the first layer in FIGS. Becomes 40 bags are manufactured.

Manufacture of Second Layer Mesh Bag The second layer of porous ceramic lump-filled mesh bag 2 shown in FIGS. 2 to 5 has a square-porous brick-like porous material having a particle size of about 2 tons and a particle size of about 60 mm. It is made by filling 20 ceramic lumps.

Manufacture of the third-layer mesh bag 3 The third-layer mesh bag 3 shown in FIGS. 2 to 5 has a composite structure using an inner bag as the mesh bag. The inner bag is made of biodegradable polylactic acid fiber and cut into 3m mesh fabric into 6m x 2m and 2m x
One that is folded in two so as to have a length of 3 m, and two sides of the L-shape are sewn together with the 3 m side as an opening. Insert the mesh bag into the measuring box along the inside of the measuring box, expand the opening of the mesh bag, put the bag-shaped inner bag in the mesh bag, expand the opening of the inner bag, and open the opening from the opening. A site-generated soil containing about 2 tons of clinker ash and reed stock is filled with a 1: 1 mixture of soil and the opening is closed. Pull the hanging rope evenly from the upper mesh of the net bag from 6 places. Then, six places are lifted and hooked on heavy machinery hooks and lifted to such an extent that the filling in the net bag becomes familiar, and lowered when the shape of the filling becomes stable.
At the same time, tie it to the suspension ring at six places on the suspension rope with a lark. Hook the suspension ring temporarily and suspend it with the opening of the mesh bag in a drawstring state, stop with the mouth drawing rope wrapped around the lower part of the hanging rope in the drawstring portion of the mesh bag, tie the opening, and leave Wrap the tied rope around the six hanging ropes coming out of the opening of the net bag. In addition, the hanging ropes are tied so as not to fall apart to form a reed-grown floor-soil-filled net bag 3 composed of three layers of clinker ash and soil generated on site. Make 20 of them.

Construction method As shown in FIG. 2, the riverbed on which the first-layer natural stone-filled mesh bag body 1 is to be installed is leveled so that there is no excessive unevenness, and five natural stone mesh bags are located offshore from the nori-butt. The body 1 is placed in two layers. That is, five rows and two stages are installed. When laminating the second tier, it is set off the first tier along the bottom. The shape of the bag body at the time of installation is about 2 m in diameter and about 40 cm in height.
On the first layer, on the third layer, the second layer of the porous ceramic lump-filled net bag 2 is stacked in five rows in the same manner as on the first layer, and on the fourth layer, clinker ash for the third layer and soil generated in the field The reed-growing floor soil-filled net bag 3 with the above is placed in five rows in the same manner as the first layer. The second layer and the third layer are also displaced along their respective bottoms in the same manner as the second layer of the first layer. FIG. 2 shows a cross section of the revetment method constructed in the above steps. FIG. 4 shows a cross section in a state where six months have passed after the construction. At the time of rising water, sediment in running water accumulates as sedimentary soil 6,
Due to the water absorption effect, water retention effect of the porous ceramic mass and clinker ash, and the absorption of nutrients from river water, a large number of reed shoots grew from the inner bag of the third layer from about one month. It is recognized that the reed root penetrates the inner bag, penetrates the bag inside the adjacent bag, and the rhizosphere is expanded, so that the net bag and the reed root are united to withstand excessive water flow. Become. The biodegradable polylactic acid fiber woven fabric used for the inner bag of the third layer has a tensile strength retention of 75% after 6 months, shows biodegradation, and almost decomposes and disappears after several years.

Example 2 In the same manner as in Example 1, 32 pieces of the net layer 1 filled with natural stone of the first layer and 2 pieces of the net mesh 2 filled with the porous ceramic mass of the second layer were used.
Zero, 24 mixed reed breeding floor soil filling net bags with clinker ash of the third layer and soil generated in the field are manufactured.

The construction method will be described with reference to FIG. FIG. 3 is a sectional view of the constructed revetment. Level the riverbed where the net bag 1 is installed so that there is no excessive unevenness. Next, a single row of porous ceramic lump-filled mesh bag 2 is installed along the slope, and a reed-growing floor soil-filled mesh bag of clinker ash and on-site generated soil is placed above the slope along the slope from the bottom. 3 is installed in two rows. Next, four first-layer natural stone-filled net bags 1 are arranged on the surface of the ground, and four of them are stacked two-tiered offshore from Hojiri. That is, four rows and two stages are installed. When laminating the second stage, it is shifted along the bottom of the first stage. Next, on the first layer, four porous ceramic mass-filled bags 2 for the second layer are stacked in four rows in the same manner as the first layer, and clinker ash for the third layer and the soil generated on site are placed thereon. Negative electrodes 3 filled in an inner bag formed of polylactic acid fibers and placed in a net bag are mixed with the mixed reed cultivation soil, and four negative electrodes 3 are arranged in four rows in the same manner as the first layer. The second layer and the third layer are also similar to the second layer of the first layer,
It is staggered along each butt. The shape of the filled net bag when placed alone is about 2 m in diameter and about 4 in height.
It is about 0 cm. Fig. 3 shows the cross section of the revetment constructed in the above process.

Even when the river is drought, as long as the natural stone-filled net bag 1 for the first layer is in contact with the waterline, the porous ceramic block of the second layer can be filled even when the embankment soil is dry. Due to the water-absorbing effect due to the porous capillary phenomenon of the mesh bag 2, it was confirmed that water was retained by the water absorption up to the uppermost portion of the reed-growing floor soil filling bag 3 mixed with clinker ash installed on the slope and the soil generated on site. . In addition, the sediment that has flowed down from the embankment whose cross-sectional state has passed six months after the construction is shown in FIG.
Due to the water retention effect of the porous ceramic mass and clinker ash and the absorption of nutrients from river water, a large number of reed shoots have grown from the inner bag of the third layer from about one month. It is recognized that the reed root penetrates the inner bag, penetrates the bag inside the adjacent bag, and the rhizosphere is expanded, so that the net bag and the reed root are united to withstand excessive water flow. Become. The biodegradable polylactic acid fiber woven fabric used for the inner bag of the third layer has a tensile strength retention of 75% after 6 months and biodegradation is observed, and after several years almost decomposes and disappears.

Test Example The experimental vessel was 100 cm long and 30 cm wide as shown in FIG.
A 70 cm deep container is provided with a water outlet at the bottom of the container opposite to the water inlet and a pump capable of supplying water at a circulation flow rate of 300 ml / min by a pump.
20cm porous ceramic mass put in 30cm thickness,
20mm to 10mm of the same porous ceramic mass
Was spread about 2 cm, and clinker ash of 5 mm or less was spread thereon. Two such containers were prepared, one was planted with reeds growing on the river site, the other was left unplanted, and the lake water shown in Table 1 was used for 70 days. Circulation was performed to compare the changes in water quality. Table 2 shows the results of the water quality analysis. Examining the suitability of clinker ash as a growth floor for reeds, the reeds supported the reed firmly in the clinker ash. Clinker ash, which has a granular and porous structure, creates suitable voids in the rhizosphere and is suitable as a material for extending the roots of plants. By planting reeds using clinker ash as a growth floor material, it will be a countermeasure against construction and flood pollution problems. Planting reeds on clinker ash reduces total nitrogen and total phosphorus, indicating that absorption by plants and rhizosphere microorganisms is taking place in clinker ash.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

The present invention has the effect of protecting the shore, embankments, etc. and at the same time protecting the natural environment.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an experimental device for water quality change.

FIG. 2 is a cross-sectional view of the revetment of the first embodiment.

FIG. 3 is a sectional view of a revetment according to a second embodiment.

FIG. 4 is a cross-sectional view of the revetment according to the first embodiment when it is aged.

FIG. 5 is a cross-sectional view of the revetment according to the second embodiment when it is aged.

[Explanation of symbols]

A container for water quality change experiment apparatus B pump for circulation C lake water D direction of water flow E porous ceramic with a particle size of 50 mm to 20 mm F porous ceramic with a particle size of 20 mm to 10 mm G clinker ash H Yoshino plant 1 Natural stone for the first layer Filling net bag 2 Porous ceramic filling net bag for the second layer Meaning 3 Mixing of clinker ash for the third layer and on-site generated soil Reed growing bed soil filling net bag 4 Water surface 5 Riverbed 6 Sedimentary soil

 ──────────────────────────────────────────────────続 き Continued on the front page (71) Applicant 596025250 Techno Chubu Co., Ltd. 3-12 Oecho, Minato-ku, Nagoya-shi (71) Applicant 598170486 Sakura Greenery Co., Ltd. 236-34 Okumachi 34 Yokkaichi-shi, Mie 34 (72) Inventor Akira Saji20, Kita-Sekiyama, Odaka-cho, Midori-ku, Nagoya-shi, Aichi Prefecture Inside Electricity Research Laboratory, Chubu Electric Power Co., Inc. (72) Inventor Ryo Nagai 5-530, Fujimae, Minato-ku, Nagoya-shi, Aichi Prefecture ) Inventor Jiji Ito 5-530 Fujimae, Minato-ku, Nagoya-shi, Aichi Prefecture Inside Meihan Resources Co., Ltd. (72) Inventor Yoshikazu Ishikawa 1-13-20 Minamisenba, Chuo-ku, Osaka-shi, Osaka Kyowa Co., Ltd. (72 ) Inventor Toshio Tanaka 236-34, Okumachi, Yokkaichi-shi, Mie Pref. Sakura Greenery Co., Ltd. 12 stock company Techno Chubu in the F-term (reference) 2D018 DA02 DA06

Claims (5)

[Claims] 1. A seawall construction method comprising a three-layer structure, wherein a first layer is provided on a ground surface with a net bag formed of natural stone in a net bag,
A mesh bag formed by placing a porous ceramic mass in a mesh bag is stacked on the mesh to form a second layer. A seawall construction method in which a third layer for planting a plant is covered by covering the surface with clinker ash or soil mixed with clinker ash, and planting the third layer. 2. The ceramic mass constituting the second layer is a mixed fired product of clinker ash and a viscous mineral, and is a porous ceramic having interconnected pores which has been solidified to maintain a water absorption of 10% or more. The revetment method described in 1. 3. A knitted or non-knotted knitted synthetic fiber yarn having a porosity of 45% or more and an elongation of 15% or more, and the length L of one side of the mesh and the diameter of natural stone or a porous ceramic body. During D, The revetment method according to claim 1 or 2, wherein the revetment is a net bag formed of netting satisfying the following relationship. 4. The revetment method according to claim 3, wherein the net bag is formed by Russell knitting. 5. The netting body according to claim 1, wherein the third layer is formed by putting clinker ash or soil mixed with clinker ash into a small inner bag having a mesh arranged in the netting bag.
The revetment method described in any one of Items 4 to 4.