JP6615403B1 - Revetment structure and construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a revetment structure capable of preventing vegetation mats arranged at the upstream end or the downstream end of a vegetation revetment area from being peeled or washed away, and as a result, ensuring a vegetation revetment in a vegetation revetment area, and a construction method thereof. . A downstream vegetation mat D is a vegetation mat laid at least at an upstream portion of an upstream vegetation mat D which is a vegetation mat laid at an upstream end of a river vegetation revetment area or a downstream end of the vegetation revetment area. The holding material 16 which covers at least the downstream part of is comprised. The holding material 16 is a net installed so as to hold down the upstream vegetation mat D or the downstream vegetation mat D. [Selection] Figure 6

Description

  The present invention relates to a revetment structure used for a vegetation revetment such as a river dike and a construction method thereof.

  Conventionally, there has been a revetment method in which multiple vegetation mats are laid on top and bottom, left and right in a river vegetation revetment area (vegetation revetment area), and adjacent vegetation mats are joined together. For the upper vegetation mat placed on the upper end (top end) and the lower vegetation mat placed on the lower end (dyke pier), there are various concerns regarding peeling and runoff caused by running water. It has been proposed (see, for example, Patent Document 1).

JP 2001-120052 A

  By the way, in addition to the above-mentioned upper end side vegetation mat and lower end side vegetation mat, the upstream vegetation mat arranged at the upstream end of the vegetation revetment area and the downstream vegetation mat arranged at the downstream end are also peeled off by running water, etc. It can be said that there is a fear. However, compared to the upper end vegetation mat and lower end vegetation mat installed from the upstream end to the downstream end of the vegetation revetment area, the upstream vegetation mat and the downstream vegetation mat installed only at the upstream end and the downstream end The problem itself such as peeling is rarely specified, and no special solution has been proposed at present.

  The present invention has been made in consideration of the above-mentioned matters. The purpose of the present invention is to prevent the vegetation mat placed on the upstream end or the downstream end of the vegetation revetment area from being peeled off or washed away, and thus to ensure the vegetation revetment of the vegetation revetment area. It is to provide a revetment structure and its construction method that can be realized.

In order to achieve the above-mentioned object, the revetment structure according to the present invention is laid at least at an upstream portion of an upstream vegetation mat, which is a vegetation mat laid at the upstream end of a river vegetation revetment region, or at a downstream end of the vegetation revetment region. A holding member that covers at least the downstream portion of the downstream vegetation mat that is the vegetation mat, and an embedded structure is provided on the upstream side of the upstream vegetation mat or the downstream side of the downstream vegetation mat that is covered by the holding member. communicating (claim 1).

  In the above revetment structure, the holding material may be a net installed so as to hold down the upstream vegetation mat or the downstream vegetation mat (Claim 2).

  In the revetment structure, a part of the holding material may be an embedded portion embedded in the ground (claim 3).

  In the bank protection structure, the buried portion may be fixed in the ground by an anchor member buried in the ground (claim 4).

In the revetment structure, the holding material may be connected to the embedded structure (claim 5).

In the revetment structure, it may be provided with suction-preventing member on the lower surface side of the holding member (claim 6).

In the above revetment structure, the vegetation mat may be one in which a lawn mat is integrated with a flexible net material (Claim 7 ).

On the other hand, in order to achieve the said objective, the construction method of the revetment structure which concerns on this invention installs the revetment structure as described in any one of Claims 1-7 by installing the said holding material in the said vegetation revetment area. (Claim 8 ).

  In the present invention, a revetment structure capable of preventing the vegetation mat disposed at the upstream end or the downstream end of the vegetation revetment area from being peeled or washed away, and thus ensuring the vegetation revetment in the vegetation revetment area, and a method for constructing the same are obtained. .

  That is, in the revetment structure of the invention according to each claim of the present application, the upstream vegetation mat or the downstream vegetation by running water is covered with the holding material at least the upstream part of the upstream vegetation mat or at least the downstream part of the downstream vegetation mat. It is possible to prevent the mat from peeling off or running away. Then, when the upstream vegetation mat or the downstream vegetation mat peels or runs away, there is a risk that the vegetation mats connected to these will start to peel off or run away in a chain. In the structure, it is possible to prevent the upstream vegetation mat or the downstream vegetation mat from peeling off, which is the starting point of such chain vegetation mats. it can.

  In the revetment structure according to the second aspect of the present invention, the retaining material that is a net has water permeability, and water supply due to rainfall or the like on the grass of the vegetation mat pressed by the retaining material is not hindered, so that the grass grows well. Can be expected.

  In the revetment structure according to the third and fourth aspects of the present invention, the retaining material partially embedded in the ground is less likely to be washed away by running water, and in particular, if the buried portion is fixed with an anchor member, it is more difficult to be washed away. Thus, it can be expected that the vegetation mat will be further prevented from peeling off.

In the revetment structure according to the first aspect of the present invention, the soil on the upstream side of the upstream vegetation mat or the downstream side of the downstream vegetation mat is eroded by the erosion action caused by running water, and this erosion is caused by the upstream vegetation mat or the downstream vegetation mat. It is possible to reliably avoid the situation where the soil reaches the lower soil and eventually the upstream vegetation mat or the downstream vegetation mat peels away.

In the revetment structure of the invention which concerns on Claim 5 , it becomes difficult to peel a holding | maintenance material more, and it can improve the stability of the holding | maintenance material which covers a vegetation mat, and by extension, stability of a vegetation mat.

In the revetment structure of the invention according to claim 6 , even if a missing portion is generated in the vegetation mat, the sucking prevention material can prevent the soil from being sucked out from the portion, and the function of the missing portion can be complemented.

In the revetment structure of the invention which concerns on Claim 7 , the operation | work which sticks a lawn mat on a vegetation revetment area can be facilitated.

It is explanatory drawing which shows roughly the structure in the middle of construction of the bank protection structure which concerns on one embodiment of this invention. It is a perspective view which shows the structure of the vegetation mat used for the said bank protection structure. It is a perspective view which shows roughly the structure of the said vegetation mat and its manufacturing method. (A)-(D) are explanatory drawings which show schematically the structure of the manufacturing method of the said vegetation mat, (E) and (F) are explanatory drawings which show schematically the structure of the construction method of the said vegetation mat. It is a longitudinal cross-sectional view which shows schematically the structure of the construction method of the said vegetation mat. It is a longitudinal cross-sectional view which shows the structure of the principal part of the said bank protection structure. (A)-(C) are the front view of the net pin used for the construction method of the said vegetation mat, a side view, and a bottom view. It is a longitudinal cross-sectional view which shows the use condition of the said net pin.

  Embodiments of the present invention will be described below with reference to the drawings.

  The revetment structure according to the present embodiment is constructed by arranging a plurality of vegetation mats D shown in FIG. 2 vertically and horizontally on the vegetation revetment area of a river, and the state of the revetment structure during the construction is shown in FIG. ing.

  Here, the vegetation mat D is, for example, a rectangular shape having a plan view of 2000 mm × 3000 mm or a square shape having a size of 2000 mm × 2000 mm, and a flexible net material 2 in which the nonwoven fabric 1 is disposed on the lower surface. And the grass mat 3 are integrated (see FIG. 2).

The nonwoven fabric 1 is a member having a substantially rectangular shape in a plan view and a chemical fiber basis weight of 40 to 80 g / m ^2, and is a polyester fiber that is a material having high durability and corrosion resistance. It is formed using a mat or the like.

  The net material 2 has substantially the same shape as the nonwoven fabric 1 in a plan view, and has a tensile strength of about 0.5 to 5 tons per 1 m width and a mesh of about 5 to 9 × 5 to 9 mm. Has been. The net material 2 is formed in a lattice shape using fibers having high durability, such as nylon, polyester, aramid, carbon, polyacetal, and the like. You may braid into the mesh body of the same mesh.

  The lawn mat 3 includes a plurality of lawns 3a and soil 3b held by the roots of the lawn 3a.

  The vegetation mat D is composed of a main body part 4 on which the lawn mat 3 is formed and a peripheral part 5 formed on the periphery of the main body part 4 and on which the lawn mat 3 is not formed. That is, the main portion 4 is a portion composed of the nonwoven fabric 1, the net material 2, and the lawn mat 3, and the peripheral edge portion 5 is a portion composed of the nonwoven fabric 1 and the net material 2. In addition, when the main-body part 4 and the peripheral part 5 of the vegetation mat D which adjoins are overlapped, the nonwoven fabric 1 is not provided in the peripheral part 5, but the peripheral part 5 may consist only of the net material 2. FIG.

  The peripheral portion 5 is formed on one side in the width direction of the vegetation mat D, for example, a peripheral portion 5a having a width of 150 mm, the peripheral portion 5b having a width of 100 mm, for example, formed on one side in the longitudinal direction of the vegetation mat D, and the vegetation mat. For example, the peripheral portion 5c having a width of 100 mm is formed on the other side in the longitudinal direction of D.

  The vegetation mat D is manufactured as follows. That is, first, as shown in FIG. 4 (A), after the nonwoven fabric 1 is laid on the field 6, a flexible net material 2 is stacked on the nonwoven fabric 1 (FIG. 4 (B)). A lawn mat 3 separately grown on the field 6 is spread over the material 2 (FIG. 4C). Then, at the stage where the roots of the turf 3a are entangled with the nonwoven fabric 1 and the net material 2 (FIG. 4D), the net material 2 together with the nonwoven fabric 1 is cut while cutting the roots of the turf 3a extending below the nonwoven fabric 1. The vegetation mat D is manufactured by peeling off from the field 6 (see FIG. 3).

  In addition, in the manufacturing method of the vegetation mat D described above, when the vegetation mat D is manufactured at the stage where the square material K (see FIG. 3) is disposed around the net material 2 at the start of the manufacture of the vegetation mat D, If the square material K etc. are taken out, the peripheral part 5 in which the lawn mat 3 is not formed can be provided in the vegetation mat D.

  Moreover, you may make it abbreviate | omit the arrangement | positioning of said square | corner K etc. and form the peripheral part 5 by crushing the peripheral part of the lawn mat 3 after vegetation mat D manufacture.

  In addition, it is desirable to form a dense mesh portion with a width of about 2 to 5 cm at each end of the peripheral portions 5a to 5c in order to prevent misalignment when the net is connected.

  According to the method for manufacturing the vegetation mat D having the above-described configuration, since the nonwoven fabric 1 is formed on the lower surface of the vegetation mat D, the amount of the roots of the turf 3a entering the vegetation mat D is less than the nonwoven fabric 1. Compared to the case where the vegetation mat D is not provided, the work of peeling off the vegetation mat D from the field 6 can be performed with a smaller force.

  The nonwoven fabric 1 can be attached to the net material 2 of the vegetation mat D by entwining the roots of the lawn 3a of the lawn mat 3 with the nonwoven fabric 1 and the net material 2. You may make it mount | wear using an adhesive agent.

  The manufacturing method of the vegetation mat D is not restricted to said structure, For example, it is good also as a structure shown below. That is, first, after laying the nonwoven fabric 1 on the field 6, the flexible net material 2 is layered on the nonwoven fabric 1, and the runner of the turf 3a is planted on the net material 2 to cover the turf 3a. At the stage where the roots are entangled with the nonwoven fabric 1 and the net material 2 and the runner grows on the lawn mat 3, the net material 2 and the nonwoven fabric 1 together with the nonwoven fabric 1 are cut while cutting the root of the lawn 3a extending below the nonwoven fabric 1. You may make it peel from.

  Further, as another method for producing the vegetation mat D, the nonwoven fabric 1 is appropriately developed on, for example, a work table, a flexible net material 2 is overlaid thereon, and a lawn mat 3 is further disposed thereon. The vegetation mat D can also be obtained by uniting these three members by bundling with staples or the like, or by other connecting means such as sewing (both not shown).

  According to this manufacturing method, although the roots of the grass 3a of the lawn mat 3 are not entangled with the nonwoven fabric 1 and the net material 2, the three parts are integrated by the connecting means. By placing anchors on the overlapping portion of 5, the lawn mat 3 can be substantially firmly attached to the slope via the nonwoven fabric 1 and the net material 2, and over time, The grass roots of the grass mat 3 are rooted on the slope while being entangled with the nonwoven fabric 1 and the net material 2. According to this manufacturing method, in addition to using the grass mat 3 grown in advance, the grass Since it is not necessary to wait for the entanglement of the mat 3 to the non-woven fabric 1 and the net material 2, the manufacturing time of the vegetation mat D can be further shortened by that time.

  Next, the construction method of the vegetation mat D is demonstrated using FIG. 1, FIG.4 (E), (F) and FIG. In FIG. 1, R is the direction in which water flows. In order to construct a vegetation mat D on a river slope (an example of a vegetation revetment area) N for vegetation revetment, first, as shown in FIG. A is excavated as appropriate, and, for example, a basket mat 7 is stretched on the excavated portion A (in addition, laying stones and futon baskets are also suitable).

  At this time, a net material 8 similar to the net material 2 described above is laid on the lower side of the cage mat 7 over an appropriate width, and the upper side portion 8a is placed on the slope N side (vegetation revetment area side) of the upper portion of the cage mat 7. ). On the other hand, as shown in FIG. 5, a net material 9 similar to the above net material 2 is provided in the vicinity of the highest water level H when water is expected, preferably in a vegetation revetment area slightly above the highest water level H. The protruding side 9a (see FIG. 1) on the river side is protruded and embedded.

  Furthermore, in the vegetation revetment area, the net material 10 similar to the net material 2 is buried over the upper and lower net materials 9 and 8. The net member 10 is embedded in consideration of the flow rate at the time of water increase, for example, in the direction in which the river flows, with an interval of 10 m to 30 m and with a part 10 a exposed to the downstream side.

  The net members 9 and 10 are preferably fixed to the river slope N with anchor pins 11 (see FIG. 5) as necessary.

  And as shown in FIG. 1, in the vegetation mat D which turned the peripheral part 5a to the upstream side, the peripheral part 5c located on the upper side (when the water flow direction R is opposite to the direction shown in FIG. 1 is installed on the opposite shore of the slope N shown in FIG. 1, it is not the peripheral portion 5 c but the peripheral portion 5 b, but the description of the case where it is the peripheral portion 5 b is omitted below. Using a crane 13 or the like, a plurality of vegetation mats D configured as described above are stretched on the slope N, for example, from the downstream side to the upstream side of the vegetation revetment area and from the lower side to the upper side of the vegetation revetment area. (See FIG. 4E).

  At this time, as shown in FIG. 5, for the vegetation mat D arranged at the lower end of the vegetation revetment area, the lower side vegetation is formed on the upper side 8 a that is projected from the net member 8 laid on the lower side of the basket mat 7. The lower part (peripheral part 5b) of the peripheral part 5 of the mat D1 is overlapped from above, and the anchor pin 11 is driven on both of them.

  Moreover, about the vegetation mat D adjacent to the up-down direction of a vegetation revetment area, the lower part of the peripheral part 5 of the upper vegetation mat D in the upper part (peripheral part 5c) of the peripheral part 5 of the lower vegetation mat D The (peripheral part 5b) is overlapped from above, and the anchor pin 11 is driven on both.

  Furthermore, about the vegetation mat D arrange | positioned by the vicinity of the highest water level H of a vegetation revetment area (connected with the protrusion side part 9a of the net material 9), the upper part (peripheral part 5c) of the peripheral part 5 is made into a net. The anchor pin 11 is placed on both sides of the projecting side 9a of the material 9 from above, and at this time, the upper end of the vegetation mat D is the projecting side due to the length dimension of the vegetation mat D. The length of the vegetation mat D may be reduced by cutting the net material 2 or the like by placing an anchor pin 11 on the overlapping portion of the protruding side 9a. It may be adjusted so that both 5c and 9a are overlapped.

  On the other hand, when a plurality of vegetation mats D are stretched from the downstream side to the upstream side of the vegetation revetment area, the downstream portion of the upstream vegetation mat D is attached to the upstream peripheral portion 5a of the downstream vegetation mat D. They are overlapped from above, and anchor pins 11 are placed on the overlapped portion, and the upstream peripheral portion 5a of the vegetation mat D on the downstream side is overlapped with the net member 10, and both the portions 10 and 5a are overlapped. Are connected by a connecting means (not shown) such as a coil wire or staple, the downstream portion of the vegetation mat D on the upstream side is overlapped with this overlapping portion, and the anchor pin 11 is hit on the overlapping portion of these three members. Set up.

  At this time, the vegetation mat D may exceed the net member 10 due to the width dimension of the vegetation mat D. In this case, the connection by the connecting means is stopped and the overlapping portion to the net member 10 is anchored. The pins 11 may be placed, or the vegetation mat D may be cut and its width dimension adjusted so that the vegetation mat D does not exceed the net material 10.

  And about each overlapping part of the vegetation mat D which adjoins in the up-down and the left-right direction, and the overlapping part of the vegetation mat D and the net material 9, these net materials 2 and 9 are embed | buried in the vegetation revetment area beforehand. The connecting member 14 may be locked. Moreover, you may make it give the covering material 15 (refer FIG. 1) to the lawn mat 3 so that all or arbitrary vegetation mats D may be covered as needed.

  In the above embodiment, as shown in FIGS. 1 and 5, the lawn mat S in which the nonwoven fabric 1 and the net material 2 are not integrated in the vegetation revetment area above the embedding area of the net material 9. Although it is stretched, it goes without saying that the vegetation mat D having the above configuration may be stretched instead of the lawn mat S.

  According to the construction method of the vegetation mat D described above, the vegetation mat D used in the construction method is a vegetation mat D having a high shape retaining property in which the strong surface root of the lawn mat 3 is firmly rooted in the nonwoven fabric 1 and the net material 2. Then, since the adjacent vegetation mats D are overlapped and fixed to the slope N with the anchor 11 or the like, the lawn mat 3 substantially connected to each other on the four sides is made of the nonwoven fabric 1 and the net material 2. Thus, the lawn mat 3 is firmly rooted on the slope N over time (see FIG. 4F).

  Therefore, it is possible to expect uniform greening vegetation on the entire slope N, and even if the river is increased immediately after the construction of the vegetation mat D, for example, the vegetation mat D does not easily collapse or peel off due to running water. In addition, it exhibits the function of a high water revetment immediately after construction, and is excellent on the landscape as well as effectively preventing erosion of the slope N by running water.

  In particular, since the net material 2 on the upper side and the upstream side of the adjacent vegetation mat D is superimposed on the net material 2 of the vegetation mat D on the lower side and the downstream side from above, the end of the net material 2 is increased when water is increased. The edge does not oppose the flowing water, and the water flows smoothly, and the flow of the vegetation mat D is more effectively prevented.

  Moreover, the nonwoven fabric 1 is formed in the lower surface of the vegetation mat D, and this nonwoven fabric 1 is the suction which prevents the suction of the soil from the back side of the vegetation mat D by flowing water like the lawn mat 3 at the time of water increase. Has a preventive effect. For this reason, for example, a deficient portion of turf 3a occurs due to insufficient growth of turf 3a at the beginning of construction, or weed intrusion after construction (including replacement of lawn with a plant-like plant). Even if the vegetation mat D has a portion where the lawn mat 3 is lost due to an increase in the loss area of the turf 3a due to the decline of the grass 3a or the lawn 3a, the non-woven fabric 1 sucks out the soil from the portion. This can be prevented and the function of the missing turf 3a can be complemented. Furthermore, it is possible to prevent the nonwoven fabric 1 from sucking soil and sand from the lower side of the peripheral portion 5 where the lawn mat 3 is not formed and the joint portion of the vegetation mat D.

  In order to obtain the above-mentioned sucking prevention effect, the non-woven fabric 1 has a plurality of holes or gaps through which the soil or sand forming the slope N is difficult to pass, and through the roots of the lawn 3a of the lawn mat 3 to some extent. Is desirable.

  Moreover, since the nonwoven fabric 1 is provided in the junction part in the vegetation mat D, in order to prevent the suction | inhalation of soil, sand, etc. by running water, a suction prevention member (for example, a suction prevention sheet) etc. is constructed on-site. This saves labor and can reduce costs in terms of construction.

  Furthermore, since the nonwoven fabric 1 does not allow soil or sand to pass therethrough, it is possible to suppress and hinder the growth of weeds that have scattered and invaded from the surroundings to the vegetation mat D after construction, thereby preventing weeds from entering.

  In the construction method of the vegetation mat D having the above-described configuration, the vegetation mat D is stretched on the slope N by using the crane 13 or the like as described above according to the weight of the vegetation mat D. You may go on.

  According to the vegetation mat D having the above configuration, and the manufacturing method and the construction method thereof, the speed of flowing water that contacts the vegetation mat D is 3 (m / s) or more by combining the nonwoven fabric 1 and the lawn mat 3. Even so, it is possible to prevent soil and sand from being sucked out by running water, and because the rhizome of the lawn mat 3 of the lawn mat 3 is entangled with the tough net material 2, the lawn is not easily peeled off by running water. Furthermore, it is possible to prevent erosion of river slopes and improve the landscape immediately after construction.

  In addition, in the construction of conventional vegetation mats that use general suck-out prevention materials, if general suck-out prevention materials are installed directly under the vegetation mat, rhizomes such as lawn will not be able to enter the slope. After construction on the lower layer, the soil was covered with about 10 to 30 cm, and lawn was pasted thereon (that is, construction was required for at least two steps), but the vegetation mat D having the above configuration and its According to the construction method, construction can be completed in only one step.

  And the revetment structure of this embodiment is at least of the vegetation mat (upstream vegetation mat) D laid in the upstream end of the slope N by the construction method of the vegetation mat D which consists of said structure, as shown in FIG. It is constructed by installing a holding material 16 that covers at least the downstream part of the vegetation mat (downstream vegetation mat) D laid at the upstream part or the downstream end of the slope N.

  Here, the holding material 16 is a net installed so as to press down at least the upstream portion of the upstream vegetation mat D or at least the downstream portion of the downstream vegetation mat D, and the same material as the net material 2 described above is used. Can do.

  Further, a part of the holding material 16 (portion that does not cover the vegetation mat D) is a buried portion 16a buried in the ground, and this buried portion 16a is brought into the ground by an anchor member 17 buried in the ground. Fixed. Specifically, before laying the upstream vegetation mat D or the downstream vegetation mat D, a hole for digging soil and burying the burying portion 16a is formed, for example, the burying portion 16a laid on the bottom of the hole. The anchor member 17 is driven into and fixed to the hole, and then the hole is backfilled in a state where the portion not to be buried in the holding material 16 is pulled out to the ground, and after rolling as necessary, on the backfill portion. A vegetation mat (upstream vegetation mat or downstream vegetation mat) D is arranged, and the holding material 16 is stacked thereon, and the holding material 16 and the anchor pin 11 penetrating the vegetation mat D are driven into an appropriate place to hold the holding material 16. The vegetation mat D is pressed down.

  In this way, a part of the holding material 16 is buried in the ground and further fixed by the anchor member 17, so that it is difficult for the holding material 16 to be washed away by running water.

  Further, as shown in FIG. 6, if the embedded structure 18 is connected to the upstream side of the upstream side vegetation mat D covered by the holding material 16 or the downstream side of the downstream vegetation mat D, the upstream side vegetation mat D can be The soil on the downstream side of the upstream side or downstream side vegetation mat D is eroded by the erosion action by running water, and this erosion reaches the soil below the upstream side vegetation mat D or the downstream side vegetation mat D, and consequently the upstream side vegetation mat. It is possible to reliably avoid the situation where D or the downstream vegetation mat D is peeled off from the slope N and washed away. As described above, the structure in which the embedded structures 18 are connected is such that the soil is backfilled when a part of the holding material 16 is embedded in the ground, and a vegetation mat (upstream vegetation) is formed in the backfill portion. This is particularly effective when a mat or a downstream vegetation mat) D is disposed. This is because the backfill portion of the soil has a lower pressure than the surroundings even if rolling is performed, and is susceptible to erosion by running water.

  Accordingly, the buried structure 18 is preferably one having high durability and imperviousness, and may be constructed, for example, by mortar or concrete being cast on site, or an existing concrete block. It may be constructed by embedding a lump such as a concrete plate or the like. In addition, although it has water permeability, the embedded structure 18 may be constructed by embedding sandbags, basket mats, discarded stones, futon baskets, and the like.

  In the revetment structure configured as described above, the upstream vegetation mat D or the downstream vegetation mat is formed by running water by covering at least the upstream part of the upstream vegetation mat D or at least the downstream part of the downstream vegetation mat D with the holding material 16. D can be prevented from peeling or running away. When the upstream vegetation mat D or the downstream vegetation mat D is peeled off or run off, the vegetation mat D connected to the upstream vegetation mat D may be peeled off or run away in a chain. In the revetment structure of the embodiment, it is possible to prevent the upstream side vegetation mat D or the downstream side vegetation mat D from peeling off as a starting point of such chained vegetation mats. Certainty can also be achieved.

  In addition, the holding material 16 that is a net has water permeability, and water supply due to rain or the like on the turf 3a of the vegetation mat D pressed by the holding material 16 is not hindered. Can do.

  In addition, this invention is not limited to said embodiment at all, Of course, it can change and implement variously in the range which does not deviate from the summary of this invention. For example, the following modifications can be given.

  In the above-described embodiment, the vegetation mat D in which the nonwoven fabric 1 is integrated in advance is used for the construction of the vegetation mat D. However, the present invention is not limited to this. Therefore, the flexible net member 2 and the lawn mat 3 that are integrated in advance may be stretched by using, for example, binding by stapling or by connecting means such as sewing.

  In this case, in order to stretch the non-woven fabric 1 on the slope N, for example, the peripheral edge of the non-woven fabric 1 or an appropriate portion may be anchored to the net members 8, 9, 10 and the like. Alternatively, the lawn mat 3 may be stretched.

  In addition, the nonwoven fabric 1 may be stretched over the entire surface of the slope N, but if it is stretched only at the portion corresponding to the joint portion of the vegetation mat D to be constructed, the necessary amount of the nonwoven fabric 1 The cost can be reduced.

  As a connecting structure of the overlapping portions of the peripheral portions 5a, 5b, and 5c of the net member 2, the peripheral portions 5a to 5c may be folded to the lower surface side, and this may be locked to the connection fitting 14, as necessary. The anchor 11 may be driven accordingly.

  Since the vegetation mat D of the said embodiment has the peripheral part 5a-5c which protrudes on the three sides, when the water flow direction R becomes the reverse of FIG. 1, or on the opposite bank of the slope N shown in FIG. Even in the case of construction, it is possible to lay the vegetation mat D by reversing the direction of FIG. 1, and the structure is simplified and compact compared to the vegetation mat D having a peripheral edge protruding on the four sides. It has become possible to achieve. However, the present invention is not limited to this, and the vegetation mat D may have peripheral portions 5a and 5b (or 5a and 5c) projecting only on two adjacent sides. In this case, for example, in order to construct the vegetation mat D on both banks of the river, two types of vegetation mats D (vegetation mat D having peripheral portions 5a and 5b and vegetation mat D having peripheral portions 5a and 5c) are used. Use it.

  Or you may drive the anchor pin 11 in the vegetation mat D itself, without providing the peripheral parts 5a-5c.

  The embedded structure 18 is not limited to a new structure when a revetment structure is constructed, but may be an existing structure. In this case, the upstream vegetation mat D or the downstream vegetation mat D or the holding material 16 may be provided so as to be continuous with the existing embedded structure 18.

  When newly installing the embedded structure 18, the holding material 16 is embedded in the embedded structure 18, used as an underlay of the embedded structure 18, locked to the embedded structure 18, or tied. May be connected to the embedded structure 18. In this case, the holding material 16 is less likely to be peeled off, and the stability of the holding material 16 covering the vegetation mat D, and thus the stability of the vegetation mat can be improved.

  In the holding material 16, a suction preventing material such as a nonwoven fabric may be provided at least on the lower surface of the portion covering the vegetation mat D.

  Further, a part of the holding material 16 may be connected to, for example, a heavy object (not shown) without being embedded. In this case, sandbags, basket mats, discarded stones, futon baskets, etc. can be used as heavy objects, and as a connection method, a heavy object is placed on the retaining material 16, and the retaining material 16 is directly or indirectly attached to the heavy object. Locking and fastening can be considered.

  The holding member 16 and the embedded structure 18 may be provided only on either the upstream part (upstream side) of the upstream vegetation mat D or the downstream part (downstream side) of the downstream vegetation mat D, but are provided on both. Is preferred.

  In addition, without using the holding material 16, the upstream portion of the upstream vegetation mat D or the downstream portion of the downstream vegetation mat D may be embedded in the ground, and further, the heavy object is placed above the embedded portion. You may make it mount. In this case, the soil or heavy material that is on the upstream side of the upstream vegetation mat D or the downstream side of the downstream vegetation mat D functions as a holding material.

  In the said embodiment, although the anchor pin 11 and the connection member 14 are used for fixation of the vegetation mat D, the net pin 19 shown to FIG. 7 (A)-(C) is used instead of one or both of these. It may be. The net pin 19 has a substantially rectangular plate-like base portion 19a and at least two (four in total in the illustrated example) insertion portions 19b provided in a row in the longitudinal direction of the base portion 19a. Presents a cross-shaped cross-shaped rod formed by sharpening the tip, and has a barb structure 19c near its root.

  The net pin 19 can firmly fix the net material 2 or the like to the ground by being pierced into the ground so as to pass through the mesh of the net material 2 or the like, as shown in FIG. By using the base portion 19a in such a direction that the longitudinal direction of the base portion 19a is the vertical direction of the slope N, the displacement of the vegetation mat D can be most effectively prevented.

  Needless to say, the above modifications may be combined as appropriate.

DESCRIPTION OF SYMBOLS 1 Nonwoven fabric 2 Net material 3 Lawn mat 3a Lawn 3b Soil 4 Main part 5 Peripheral part 5a-5c Peripheral part 6 Farm 7 Basket mat 8 Net material 8a Upper side 9 Net material 9a Protruding side 10 Net material 10a Part 11 Anchor pin 12 Hook member 13 Crane 14 Connection member 15 Covering soil 16 Holding material 17 Anchor member 18 Embedded structure 19 Net pin 19a Base portion 19b Insertion portion 19c Return structure D Vegetation mat S Lawn mat

Claims (8)

Cover at least the upstream part of the upstream vegetation mat, which is a vegetation mat laid at the upstream end of the river vegetation revetment area, or at least the downstream part of the downstream vegetation mat, which is a vegetation mat laid at the downstream end of the vegetation revetment area It has a holding material ,
A revetment structure in which an embedded structure is connected to the upstream side of the upstream side vegetation mat or the downstream side of the downstream side vegetation mat covered with the holding material .   The revetment structure according to claim 1, wherein the holding material is a net installed so as to hold down the upstream vegetation mat or the downstream vegetation mat.   The revetment structure according to claim 1 or 2, wherein a part of the holding material is a buried portion buried in the ground.   The revetment structure according to claim 3, wherein the buried portion is fixed in the ground by an anchor member buried in the ground. The revetment structure according to any one of claims 1 to 4, wherein the holding material is connected to the embedded structure. The revetment structure as described in any one of Claims 1-5 by which the suction prevention material is provided in the lower surface side of the said holding material . The revetment structure according to any one of claims 1 to 6, wherein the vegetation mat is obtained by integrating a lawn mat with a flexible net material . The construction method of the bank protection structure which builds the bank protection structure as described in any one of Claims 1-7 by installing the said holding material in the said vegetation bank protection area.