JP5771027B2 - Avalanche prevention structure - Google Patents

Description

The present invention relates to an avalanche prevention structure provided with an avalanche prevention fence that prevents an avalanche from occurring , and more particularly to an avalanche used to prevent an avalanche in a small step formed in the middle of a slope using the avalanche prevention fence. Regarding prevention structure.

  Conventionally, an avalanche prevention fence has been provided in order to prevent avalanches on slopes in snowy regions.

  As described in Patent Document 1, a conventional avalanche prevention fence includes a plurality of support columns arranged upright from a slope, a plurality of cross members laid between the support columns, and troughs. It has a pillar that supports it diagonally from the side. The lower ends of these pillars and stanchions are fixed to a concrete base portion embedded in the slope soil. The avalanche prevention fence constructed in this way receives snow on the slope on the surface surrounded by the pillars and cross members, and the pressure received from the snow is buried in the soil of the slope through the pillars and the conservatory pillars. The avalanche is prevented by catching it on the foundation part of the concrete.

Japanese Patent Laid-Open No. 7-180116

  However, since the avalanche prevention fence as described above needs to be provided with a concrete base portion in order to support the support column and the retaining column, it takes time and labor for the construction.

  On the other hand, a structure using a pedestal made of a steel plate or the like is conceivable as a structure that facilitates construction without using a concrete base portion. In this structure, a pillar is erected near the mountain side end of a steel pedestal, a conserving column is provided on the trough side of the column, the lower end of the conserving column is fixed to the pedestal, and the pedestal uses an anchor bolt. Fixed to the slope.

  However, in such a structure, the weight of the snow on the slope is received only on the surface surrounded by the pillars and cross members, so a large moment acts to cause the avalanche prevention fence to fall to the valley side, and the avalanche works. There is a risk that the prevention fence will fall from the anchor bolt that fixes the base. Therefore, in order to prevent the avalanche prevention fence from falling, it is necessary to suppress the falling by fixing it to the ground with more anchor bolts, which may increase the labor of construction.

  In addition, it has been conventionally practiced to form a step in the middle of the slope to prevent avalanches and to prevent snow falling on the slope on the mountain side from falling by the resistance of the snow that accumulates on the step. However, depending on the installation location of the steps, it may be difficult to widen the steps due to obstacles such as trees and rocks. In such a case, it is conceivable that the width of the step is substantially expanded by installing an avalanche prevention fence below the step and receiving the snow that protrudes from the step to the valley side by the avalanche prevention fence. However, when an avalanche prevention fence is installed on the slope to expand such a small step, the avalanche prevention fence is given a weight of snow that protrudes continuously from the snow on the small step, causing a large overturning moment to occur. Since it is attached to the prevention fence, it will be easier to fall.

  Therefore, as a result of intensive studies to solve such problems, the present inventor has actively used the weight of the snow on the slope, so that the avalanche prevention fence that exceeds the fall moment or greatly diminishes. The pedestal portion can be positively pressed by the snow on the slope so that a moment to prevent the fall of the snow is generated, and the snow protruding continuously from the snow on the step can be received. Proposed avalanche fence.

  The present invention has been made in view of the circumstances as described above, and while using the weight of snow to prevent the fall of the fence, an avalanche prevention fence that is easy to construct, and a step using the same An object is to provide an avalanche prevention structure that can be easily expanded.

In order to solve the above problems, the avalanche prevention structure of the present invention includes an avalanche prevention fence that prevents avalanches from occurring on a slope, and an anchor bolt that fixes the avalanche prevention fence to the ground of the slope. The avalanche prevention fence has a shape that can be installed on a slope, and has a mountain side end and a valley side end, and the mountain side end is on the mountain side of the slope. Arranged, a pedestal portion whose valley side end is arranged on the valley side of the slope, a plurality of columns rising from the pedestal unit, and spanned between the columns, and snow between the columns A snow receiving portion having a shape that can be received, and a connecting portion that connects a mountain side surface of the support column and a portion of the pedestal portion closer to the mountain side than the support column. It is arranged at a position closer to the valley side end than the mountain side end of the pedestal, Part of the mountain side than the strut of the seat portion has a shape capable of placing the snow, the anchor bolt, mountain side end of the upper said pedestal portion together with the lower portion is embedded in the ground of the slopes It is characterized by fixing the mountain side edge part of the said base part to the ground of the said slope by being connected to a part .

According to such a configuration, the strut of the avalanche prevention fence is disposed at a position closer to the valley end than the mountain end of the pedestal portion, and the mountain side portion of the pedestal portion on the mountain side from the strut has snow. Since it has a shape that can be placed, it is possible to place more snow on the slope on the mountain side than the support on the pedestal, and the snow on the slope presses the part on the mountain side than the support on the pedestal be able to. As a result, the weight of the snow on the slope is actively used to generate a moment that prevents the avalanche fence from overturning that exceeds or significantly reduces the moment to overturn the avalanche fence. As a result, the fall of the avalanche prevention fence can be effectively prevented, and as a result, avalanche can be prevented.
And according to said structure, since a connection part connects between the mountain | side side surface of a support | pillar, and the mountain side part rather than the said support | pillar of the said pedestal part, the connection between a support | pillar and a pedestal part becomes stronger. , Struts are hard to break. A bending load is applied to the support column in the direction from the mountain side to the valley side under the pressure of snow, but the connecting portion supports the support column from the mountain side, so that a tensile load is applied to the connecting portion. Moreover, the bending load by the snow pressure from the mountain side also acts on a connection part. Therefore, the connecting portion may be designed to have a tensile strength capable of supporting a tensile load while taking this bending load into consideration.
Further, according to the above configuration, the anchor bolt has its lower part embedded in the ground of the slope and its upper part connected to the mountain side end of the pedestal part, whereby the mountain side end of the pedestal part is regulated. Since it is fixed to the ground of the surface, it is possible to reliably prevent the avalanche fence from falling over at a position far from the column.

Also, since by using the weight of the snow on slopes to prevent the overturning of the avalanche fences, can adopt a simple and inexpensive to reduce the number of anchor bolts to secure the pedestal to the ground of slopes Therefore, the construction is greatly facilitated.

  It is preferable that the snow receiving portion rises from a valley side end portion of the pedestal portion.

  According to this configuration, the mountain side portion of the pedestal portion is wider than the support column, and therefore the fall prevention effect can be improved by making full use of the weight of snow accumulated on the pedestal portion.

  It is preferable to further include a biting portion that is provided so as to protrude toward the slope at a portion of the pedestal portion that is closer to the mountain than the column, and has a shape that can bite into the ground of the slope.

  According to this configuration, the biting portion provided on the mountain side portion of the pedestal portion protrudes toward the slope and bites into the slope ground, so that the snow on the slope is a snow receiving portion between the posts. When a force is applied to the avalanche, the avalanche prevention fence is prevented from shifting to the valley side along the slope surface. At the same time, the frictional resistance between the biting part and the slope ground further increases the moment to prevent the avalanche prevention fence from overturning, so it is possible to more effectively prevent the avalanche prevention fence from overturning. .

  The biting portion is preferably provided so as to protrude toward the slope at the mountain side end portion of the pedestal portion. In this case, since the biting portion is provided at the mountain side end portion of the pedestal portion and is disposed at the position farthest from the support column in the pedestal portion, the moment that suppresses the overturn generated by the biting portion is the largest.

  The pedestal portion further includes a snow mounting portion that extends along the width direction of the pedestal portion at a portion of the pedestal portion from the support column and has a shape capable of placing snow piled on the mountain side of the snow receiving portion. Is preferred.

  According to such a configuration, since the snow on the slope is placed on the snow placing portion provided on the mountain side of the pedestal portion of the pedestal portion, the moment for preventing the avalanche prevention fence from falling further increases, thus preventing the avalanche. It becomes possible to prevent the fall of the fence more effectively.

It is preferable that the snow placing portion extends along the width direction of the pedestal at the mountain side end of the pedestal. In this case, since the snow-carrying part is provided at the mountain side end of the pedestal part and is disposed at the position farthest from the support column in the pedestal part, the moment for preventing the fall caused by the snow-carrying part is the largest.
The pedestal portions may be arranged on both sides in the width direction of the avalanche prevention fence, and the snow placing portions may connect the pedestal portions on both sides.

  From the bite part which is provided so as to protrude toward the slope at the mountain side portion of the pedestal part than the pillar, and has a shape capable of biting into the ground of the slope, and from the pillar of the pedestal part And a snow placing portion extending along the width direction of the pedestal portion at the mountain side portion and having a shape capable of placing snow piled on the mountain side with respect to the support column, the biting portion and the snow placing portion It is preferable that the part is integrally formed.

According to this configuration, the biting portion and the snow placing portion can be easily integrally formed of steel or the like, and the work for attaching the biting portion and the snow placing portion to the pedestal portion is facilitated.
It is preferable that the said anchor bolt has fixed the said snow mounting part to the ground of the said slope with the mountain side edge part of the said base part. According to this structure, it is possible to obtain the moment which suppresses the fall of the avalanche prevention fence by both the snow and the anchor bolt that are placed on the snow placing portion at the mountain side end portion of the pedestal portion.

The avalanche prevention structure is used to prevent an avalanche from occurring in a small step formed in the middle of a slope, and the avalanche prevention fence is on the small step on the valley side of the slope. It is preferable that it is installed at a position where it can receive the snow protruding continuously to the valley side of the step .

  According to this configuration, the avalanche prevention fence is installed at a position on the valley side of the slope so that it can receive the snow protruding to the valley side of the small step continuously with the snow on the small step. Therefore, the avalanche prevention fence is given the weight of the snow that protrudes continuously from the snow on the steps to the pedestal as well as the snow receiving part between the supporting pillars. The overturning moment generated in the step is largely offset by the overturning inhibiting moment generated in the pedestal portion, making it difficult to overturn, and the width of the small step can be substantially enlarged.

  The pedestal portion has an extended portion that extends by extending a mountain side end portion of the pedestal portion along the surface of the small step, and further includes a small step fixing means for fixing the extended portion to the ground of the small step. It is preferable that the extension portion is fixed to the ground of the small step by the small step fixing means.

  According to such a configuration, since the extended portion extending to the mountain side of the pedestal portion extends to the surface of the small step and is fixed to the small step ground by the small step fixing means, it can be easily and reliably fixed to the small step ground.

  In addition, the weight of the snow on the steps is applied on the extended portion, and the fall prevention moment is further increased, so that the avalanche prevention fence is more difficult to fall.

As described above, according to the avalanche prevention structure of the present invention, the weight of the snow on the slope is actively used to prevent the avalanche prevention fence from being overturned so as to exceed the fallover moment or greatly reduce it. Moment can be generated, and the avalanche prevention fence can be effectively prevented from falling, and as a result, avalanche can be effectively prevented. Also, since by using the weight of the snow on slopes to prevent the overturning of the avalanche fences, can adopt a simple and inexpensive to reduce the number of anchor bolts to secure the pedestal to the ground of slopes Therefore, the construction is greatly facilitated.

  Further, according to the avalanche prevention structure of the present invention, the weight of snow continuously protruding from the snow on the steps is given to the avalanche prevention fence in a distributed manner not only in the support column but also in the pedestal part. The overturning moment generated in the snow receiving portion is largely offset by the overturning inhibiting moment generated in the pedestal portion, and the avalanche prevention fence becomes difficult to fall over. As a result, the width of the small step can be substantially enlarged.

It is a partially notched side view concerning embodiment of the avalanche prevention fence of this invention. It is a top view of the avalanche prevention fence of FIG. It is a front view of the avalanche prevention fence of FIG. It is sectional drawing which shows the avalanche prevention structure which installed the avalanche prevention fence of FIG. 1 in the valley side of the small step in a slope as one embodiment of the avalanche prevention structure of this invention. It is an expanded sectional view of the avalanche prevention fence of FIG. It is sectional drawing which shows the avalanche prevention structure which installed the avalanche prevention fence in the valley side of the small step in a slope, and extended the base part to the small step as other embodiment of the avalanche prevention structure of this invention. It is a front view which shows the example provided with the snow receiving part comprised by the wire rope which is a modification of the avalanche prevention fence of this invention, and a wire mesh. It is a front view which shows the example provided with the snow receiving part comprised by the several ladder-shaped member which is the other modification of the avalanche prevention fence of this invention. It is a front view which shows the example provided with the snow receiving part comprised by the several grating panel which is the other modification of the avalanche prevention fence of this invention. It is a front view which shows the example provided with the snow-receiving part comprised by the some punching metal which is another modification of the avalanche prevention fence of this invention. As a modification of the avalanche prevention structure of the present invention, a sectional view showing an avalanche prevention structure in which two avalanche prevention fences are arranged side by side in the vertical direction of the slope on the valley side of the slope on the slope and the pedestal is extended to the stage. It is. It is a figure which shows the plane arrangement | positioning on the slope of the avalanche prevention structure of FIG. It is a figure which shows the plane arrangement | positioning on the slope of the avalanche prevention structure which connected the base part of the two avalanche prevention fences with the connection material as another modification of the avalanche prevention structure of this invention.

  Hereinafter, an avalanche prevention fence according to the present invention will be described with reference to the drawings.

  An avalanche prevention fence 1 shown in FIG. 1 is an avalanche prevention fence that prevents an avalanche from occurring on a slope S1.

  The avalanche prevention fence 1 shown by FIGS. 1-3 is the avalanche prevention fence 1 which prevents generation | occurrence | production of the avalanche in slope S1. The avalanche prevention fence 1 includes a pedestal portion 2, a plurality of support columns 3, a snow receiving portion 4, an L-shaped tipping prevention member 5, and a connecting portion 8.

  The pedestal portion 2 is made of a pair of I-shaped steels or flat steel plates, and has a shape that can be installed in surface contact with the surface of the slope S1. The pedestal portion 2 has a mountain side end 2a and a valley side end 2b, the mountain side end 2a is arranged on the mountain side of the slope S1, and the valley side end 2b is arranged on the valley side of the slope S1. Is done.

  The pedestal 2 transmits most of the external force received from the snow A1 on the slope S1 to the slope anchor bolts SB1 and SB2. The forces transmitted to the anchor bolts SB1 and SB2 are received by the frictional resistance between the anchor bolts SB1 and SB2 and the ground G.

  The pedestal portion 2 is preferably manufactured from a lightweight and high-strength steel plate or precast concrete plate in consideration of various conditions such as reduction of assembly work and snow load.

  The plurality of struts 3 are columnar bodies made of H-shaped steel or the like, and stand up vertically from the pedestal portion 2. In the present embodiment, one column 3 is erected on each of the I-shaped steels constituting the pedestal portion 2.

  The column 3 is disposed closer to the valley side end 2b than the mountain side end 2a of the pedestal portion 2, and the mountain side portion 2c of the pedestal portion 2 is capable of carrying snow. Have

  The snow receiving portion 4 is constructed between the columns 3 and has a shape capable of receiving snow between the columns 3. In the snow receiving portion 4 of the present embodiment, a plurality of beam members 11 and 12 made of round steel or the like are disposed between the support columns 3 in the horizontal direction with a space therebetween.

  As shown in FIGS. 4 to 5, the uppermost beam member 11 and the beam member 12 positioned below the upper beam member 11 have a force in the direction in which snow A1 on the slope S1 is directed toward the valley along the slope S1. Although F1 acts, load F2 by the snow A1 located above the beam material 11 also acts on the uppermost beam material 11. Therefore, the uppermost beam member 11 is designed to have a cross-sectional shape and dimensions such that the bending strength is higher than the beam member 12 located below the upper beam member 11 (for example, a round steel with a large diameter). Etc.).

  The installation interval between the beam members 11 and 12 or between the beam members 12 is preferably about 20 cm, although it depends on the snow quality in the area.

  In the avalanche prevention fence 1 shown in FIGS. 1 to 3, the column 3 is arranged closer to the valley side end 2 b than the mountain side end 2 a of the pedestal portion 2, and is closer to the mountain side than the column 3 in the pedestal portion 2. Since the portion 2c has a flat shape on which snow can be placed, more snow A1 (see FIG. 4) on the slope S1 can be placed on the mountain-side portion 2c than the column 3 in the pedestal portion 2. The snow-side A1 on the slope S1 can hold down the mountain-side portion 2c of the pedestal 2 relative to the support column 3. Accordingly, the weight of the snow A1 on the slope S1 is positively used to prevent the avalanche prevention fence 1 from being overturned so as to exceed the moment M1 that attempts to overturn the avalanche prevention fence 1 or to significantly reduce the loss. The moment M2 can be generated, and the avalanche prevention fence 1 can be effectively prevented from falling, and as a result, an avalanche can be prevented.

  The L-shaped toppling prevention member 5 is provided so as to protrude toward the slope S1 in the portion 2c on the mountain side of the column 3 of the pedestal 2. The fall prevention member 5 includes a biting portion 6 and a snow placing portion 7, and the biting portion 6 and the snow placing portion 7 are integrally formed of L-shaped steel or the like.

  The biting portion 6 is provided along the width direction D (see FIG. 2) of the pedestal portion 2 so as to protrude toward the slope S1 at the portion 2c on the mountain side of the column 3 of the pedestal portion 2, and the slope S1. It has a shape that can bite into the ground G. The biting portion 6 provided in the portion 2c on the mountain side of the support column 3 of the pedestal portion 2 protrudes toward the slope S1, and can bite into the ground G of the slope S1.

  The snow placing portion 7 extends along the width direction D (see FIG. 2) of the pedestal portion 2 at the mountain-side portion 2 c of the pedestal portion 2, particularly at the mountain-side end portion 2 a, and is hillside from the support column 3. It has a shape that can be loaded with snow. When the snow A1 on the slope S1 is placed on the snow-carrying portion 7, the moment M2 for preventing the avalanche prevention fence 1 from overturning further increases, so that the avalanche prevention fence 1 can be more effectively prevented from overturning. It becomes possible.

  The connecting portion 8 is a columnar member that connects the mountain side surface of the support column 3 and the portion 2c of the pedestal portion 2 that is closer to the mountain side than the support column 3, and can be used not only for tensile load but also for bending load due to snow pressure from the mountain side. Manufactured from a material that can withstand strength, for example, square steel or H-shaped steel. Since the connection part 8 connects between the mountain side surface of the support column 3 and the portion 2c of the pedestal part 2 which is closer to the mountain side than the support column 3, the connection between the support column 3 and the pedestal part 2 becomes stronger. Become.

(Calculation of the fall prevention moment of the avalanche prevention fence 1)
As shown in FIG. 5, the snow receiving portion 4 of the avalanche prevention fence 1 has a force exerted downward by the force due to the snow A1 on the slope S1, that is, the force F1 pushed along the slope S1 and the snow weight. F2 acts, whereby a fall moment M1 that falls the avalanche prevention member 1 to the valley side acts on the snow receiving portion 4.

  When calculating the overturning moment M1, for example, the slope S1 in the forces F1 and F2 received from the snow A1 on the slope S1 acting on the observation points of the beam members 11 and 12 constituting the column 3 and the snow receiving portion 4 The moment at each observation point is obtained from the component in the direction parallel to the base and the distance from the valley side end 2b of the pedestal 2 to each observation point, and this is parallel to the slope S1 of the columns and beams 11 and 12. Further, the overturning moment M1 can be obtained by integrating the moment over the entire surface of the portion facing the mountain side.

  Here, the parallel component of the force received from the snow A1 on the slope S1 is not only the force F1 pushing along the slope S1, but also the component parallel to the slope S1 of the load F2 acting downward due to the snow weight. It becomes the resultant force of F21.

  On the other hand, when the fall prevention moment M <b> 2 that prevents the avalanche prevention fence 1 from falling is calculated, it is given to the observation points on the surface of the pedestal 2 of the avalanche prevention fence 1 and the snow placing part 7 of the L-shaped fall prevention member 5. Of the forces F1 and F2 received from the snow A1 on the slope S1, the vertical downward component going vertically downward toward the slope S1 and the distance from the valley side end 2b of the pedestal 2 to each observation point, The fall prevention moment M2 can be obtained by obtaining the moment at the observation point and integrating the moment over the entire surface of the pedestal 2 and the part of the fall prevention member 5 facing the normal plane S1. .

  Here, the downward components of the forces F1 and F2 received from the snow A1 on the slope S1 are substantially equal to the component F22 vertically downward toward the slope S1 of the load acting downward due to the weight of snow.

  The difference moment between the overturning moment M1 and the overturning suppression moment M2 calculated as described above is received by the slope anchor bolts SB1 and SB2 and the biting portion 6 of the overturn prevention member 5.

  The portion of the pedestal portion 2 that is closer to the valley than the support column 3 and the snow receiving portion 4 is concealed from above by the snow receiving portion 4, so that snow does not accumulate or only a small amount of snow accumulates. It is considered that there is no possibility of giving a falling moment to the part 2.

  In addition, when the avalanche prevention fence 1 is actually installed on the slope S1, a suspension rope may be attached from the mountain side of the slope S1 to the upper part of the avalanche prevention fence 1, and in that case, due to the tension by the suspension rope. Further, the overturning suppression moment M2 increases.

(Description of the avalanche prevention structure 30)
As shown in FIG. 4, using the avalanche prevention fence 1 configured as described above, an avalanche prevention structure 30 that prevents the occurrence of avalanches in the small steps S2 formed in the middle of the slope S1 can be configured. it can. The avalanche prevention structure 30 includes the avalanche prevention fence 1 configured as described above, and slope anchor bolts SB1 and SB2 for fixing the pedestal portion 2 to the ground G of the slope S1.

  A lower portion of the slope anchor bolt SB1 is embedded in the ground G, and an upper portion of the slope anchor bolt SB1 passes through an intermediate position of the base portion 2. And the base part 2 is being fixed to the ground G by the nut N being fastened by the upper part of the said slope anchor bolt SB1. Similarly, the lower portion of the slope anchor bolt SB2 is embedded in the ground G, and the upper portion of the slope anchor bolt SB2 penetrates the portion near the mountain side end portion 2a of the pedestal portion 2 and the fall prevention member 5. . And the base part 2 and the fall prevention member 5 are being fixed to the ground G by fastening the nut N to the upper part of the said slope anchor bolt SB2. As a result, the avalanche preventing member 1 is firmly fixed to the ground G by the slope anchor bolts SB1 and SB2.

  In this structure, the avalanche prevention fence 1 allows the snow A1 on the slope S1 that protrudes toward the valley side of the small step S2 continuously from the snow A2 on the small step S2 on the valley side of the small step S2 in the slope S1. It is installed in a position where it can be received. Therefore, the avalanche prevention fence 1 is provided with a snow load that continuously protrudes from the snow A2 on the small step S2 and is distributed and applied not only to the snow receiving part 4 between the pillars 3 but also to the pedestal part 2. 3 and the falling moment M1 generated in the snow receiving portion 4 are largely offset by the falling-inhibiting moment M2 generated in the pedestal portion 2, thereby greatly reducing the falling moment M1 acting on the slope anchor bolts SB1 and SB2. be able to. As a result, the avalanche prevention fence 1 becomes difficult to fall to the valley side, and the width of the small step S2 can be substantially enlarged.

  In the present embodiment, in addition to the slope anchor bolt SB1 that fastens the intermediate position of the pedestal portion 2, the slope anchor bolt SB2 penetrates the fall prevention member 5 together with the portion near the mountain end 2a of the pedestal portion 2. Then, the pedestal 2 and the overturning prevention member 5 are fastened to the ground G with the nut N, so that the overturning inhibiting moment M2 can be increased at a position far from the support column 3, and the overturn of the avalanche prevention fence 1 can be prevented more reliably. .

(Description of other avalanche prevention structure 31)
In the avalanche preventing structure 30 shown in FIG. 4, the pedestal 2 is in contact with the slope S1 below the step S2, but the present invention is not limited to this, and is shown in FIG. As described above, the mountain side portion of the base 2 may be extended to the surface of the small step S2.

  Specifically, in the avalanche prevention structure 31 shown in FIG. 6, the pedestal portion 2 has an extension portion 21 that extends by extending the mountain side end portion 2 a of the pedestal portion 2 along the surface of the small step S <b> 2. . The avalanche preventing structure 31 includes a small anchor bolt FB for fixing the extended portion 21 to the ground G of the small step S2. The extended portion 21 is fixed to the ground G of the small step S2 by the small anchor bolt FB. Yes. Therefore, it can be easily and reliably fixed to the ground G of the small step S2.

  Moreover, since the load due to the snow A2 on the small step S2 acts on the extended portion 21, the overturning inhibiting moment M2 further increases, and as a result, the avalanche prevention fence 1 becomes more difficult to fall.

  Further, in the avalanche prevention structure 31 shown in FIG. 6, since the L-shaped fall prevention member 5 is arranged on the surface of the small step S2, the snow A2 on the small step S2 is placed on the snow placing portion 7 of the fall prevention member 5. As a result, the overturning inhibiting moment M2 is further increased.

(Features of this embodiment)
(1)
In the avalanche prevention fence 1 of the present embodiment, the support column 3 is arranged at a position closer to the valley side end portion 2b than the mountain side end portion 2a of the pedestal portion 2, and the portion 2c of the pedestal portion 2 on the mountain side from the support column 3 is located. Therefore, the snow A1 on the slope S1 can be placed on the mountain side portion 2c more than the support 3 in the pedestal 2, and the snow A1 on the slope S1 can place the pedestal. The part 2c on the mountain side of the column 2 in the part 2 can be pressed. Thereby, the load of the snow A1 on the slope S1 is positively used, and the fall of the avalanche prevention fence 1 that exceeds or greatly reduces the moment M1 that causes the avalanche prevention fence 1 to fall is suppressed. The moment M2 can be generated, and the avalanche prevention fence 1 can be effectively prevented from falling, and as a result, an avalanche can be prevented.

Moreover, since the fall of the avalanche prevention fence 1 is prevented using the load of the snow A1 on the slope S1, the number of anchor bolts B for fixing the pedestal portion 2 to the ground G of the slope S1 can be reduced easily and easily. Since an inexpensive one can be adopted, construction is greatly facilitated.

(2)
Since the snow receiving portion 4 rises from the valley side end portion 2 b of the pedestal portion 2, the mountain side portion 2 c is wider than the support column 3 in the pedestal portion 2, and the snow load that accumulates on the pedestal portion 2 is Sufficiently can be used to improve the fall prevention effect.

(3)
Moreover, in the avalanche prevention fence 1 of this embodiment, the biting part 6 provided in the part 2c of the mountain side rather than the support | pillar 3 of the base part 2 protrudes toward the slope S1, and bites into the ground G of the slope S1. When the snow A1 on the slope S1 applies a force to the snow receiving portion 4 between the columns 3, the avalanche prevention fence 1 is prevented from shifting to the valley side along the surface of the slope S1. At the same time, the frictional resistance between the biting portion 6 and the ground G of the slope S1 further increases the moment M2 for preventing the avalanche prevention fence 1 from overturning, so that the avalanche prevention fence 1 can be prevented more effectively. It becomes possible to do.

(4)
Moreover, in the avalanche prevention fence 1 of this embodiment, since the biting part 6 is provided so that it may protrude toward the slope S1 in the mountain side edge part 2a of the base part 2, in the base part 2, it is most from the support | pillar 3. The fall prevention moment M2 that is arranged at a distant position and is generated by the biting portion 6 becomes the largest, and as a result, the fall prevention effect is improved.

(5)
Moreover, in the avalanche prevention fence 1 of this embodiment, it extends along the width direction of the said base part 2 in the part 2c on the mountain side rather than the support | pillar 3 of the base part 2, and mounts the snow which accumulates on the mountain side rather than the snow receiving part 4. Is further provided with a snow mounting portion 7 having a shape that allows the snow A1 on the slope S1 to be placed on the snow mounting portion 7 provided in the portion 2c on the mountain side of the column 3 of the pedestal portion 2, Since the moment M2 for preventing the avalanche prevention fence 1 from overturning further increases, it is possible to more effectively prevent the avalanche prevention fence 1 from overturning.

(6)
Moreover, in the avalanche prevention fence 1 of this embodiment, since the snow mounting part 7 is provided in the mountain side edge part 2a of the base part 2, and is arrange | positioned in the position farthest from the support | pillar 3 in the base part 2, a snow mounting part The moment M2 that suppresses the overturn caused by 7 is the largest.

(7)
Moreover, in the avalanche prevention fence 1 of this embodiment, since the L-shaped fall prevention member 5 is comprised by integrally forming the biting part 6 and the snow mounting part 7, this fall prevention member 5 is made into L It can be easily integrally formed with mold steel or the like, and the work of attaching the biting portion 6 and the snow placing portion 7 to the pedestal portion 2 is also easy.

(8)
Moreover, in the avalanche prevention fence 1 of this embodiment, since the connection part 8 has connected between the mountain side side of the support | pillar 3, and the part 2c of the base part 2 rather than the said support | pillar 3, the support | pillar 3 and the base The connection with the portion 2 becomes stronger and the support column 3 is less likely to be broken. A bending load is applied to the support column 3 in a direction toward the valley side under the snow pressure from the mountain side. However, the connecting portion 8 supports the support column 3 from the mountain side, so that a tensile load is applied to the connecting portion 8. Further, a bending load due to snow pressure from the mountain side also acts on the connecting portion 8. Therefore, the connecting portion 8 may be designed to have a tensile strength capable of supporting a tensile load while taking this bending load into consideration.

(9)
Moreover, in the avalanche prevention structure 30 of this embodiment, as shown in FIGS. 4-5, it is the avalanche prevention structure 30 which prevents generation | occurrence | production of the avalanche in the small step S2 formed in the middle of slope S1, Comprising: The avalanche prevention fence 1 and the slope anchor bolt SB that fixes the pedestal 2 to the ground G of the slope S1 are provided, and the avalanche prevention fence 1 is smaller than the step S2 of the slope S1. On the valley side, it is installed at a position where it can receive the snow that protrudes toward the valley side of the small step S2 continuously with the snow A2 on the small step S2.

  According to this structure, the avalanche prevention fence 1 can receive the snow which protrudes to the valley side of the said small step S2 continuously with the snow A2 on the small step S2 in the valley side rather than the small step S2 in the slope S1. Since the avalanche prevention fence 1 is installed at such a position, the snow load continuously protruding from the snow A2 on the small step S2 is distributed not only to the snow receiving part 4 between the support columns 3 but also to the pedestal part 2. To be granted. As a result, the overturning moment M1 generated in the support column 3 and the snow receiving portion 4 is largely offset by the overturning inhibiting moment M2 generated in the pedestal portion 2, and it becomes difficult to overturn, and the width of the small step S2 is substantially enlarged. Is possible.

  Further, as shown in FIG. 5, by combining the small step S2 and the avalanche prevention fence 2, the height of the avalanche prevention fence 1 is higher than the case where the avalanche prevention fence 1 is provided alone on the slope without the steps. Even if the height is lowered, the snow protruding to the valley side at the upper end portions of the support column 3 and the snow receiving portion 4, that is, the snowfall is hardly generated, and the avalanche preventing effect is greatly improved.

(10)
Further, in the avalanche prevention structure 31 of the present embodiment, as shown in FIG. 6, the pedestal portion 2 has an extension portion 21 that extends so that the mountain side end portion 2 a of the pedestal portion 2 extends along the surface of the small step S <b> 2. Further, a small anchor bolt FB for fixing the extended portion 21 to the ground G of the small step S2 is further provided, and the extended portion 21 is fixed to the ground G of the small step S2 by the small step anchor bolt FB. In this configuration, since the extension portion 21 extending to the mountain side of the pedestal portion 2 extends to the surface of the small step S2 and is fixed to the ground G of the small step S2 by the small step anchor bolt FB, it is easily and surely fixed to the ground G of the small step S2. can do.

  In addition, since the load of the snow A2 on the small step S2 is applied on the extended portion 21 and the fall prevention moment M2 is further increased, the avalanche prevention fence 1 is more difficult to fall.

(Modification)
In the present embodiment, as shown in FIGS. 1 to 3, the snow receiving portion 4 has a plurality of beam members 11, 12 made of round steel or the like arranged in the horizontal direction at intervals between the columns 3. However, the present invention is not limited to this, and a snow receiving portion having another configuration may be adopted as long as it can receive the snow A1 on the slope S1. Also good.

  For example, in the snow receiving portion 40 shown in FIG. 7, a plurality of wire ropes 41 are horizontally arranged between the support posts 3 and are fixed to the support posts 3 with a wire grip or the like. The wire 41 is fixed to the rope 41. In the case of the snow receiving portion 40 having such a configuration, a small snow lump can be held by the wire mesh 42. Moreover, not only the snow pressure received from the mountain side along the slope S1 but also the load due to the snow accumulated above the upper end of the fence (see the vertical load F2 in FIG. 4) acts on the upper end of the avalanche prevention fence. A large load is applied. Therefore, in order to reinforce the upper end portion of the fence, a reinforcing beam member 49 is provided between the upper end portions of the column 3 in the avalanche prevention fence shown in FIG. The beam member 49 is manufactured from a member having high bending strength such as a round pipe, H-shaped steel, and square steel.

  Further, the snow receiving portion 43 shown in FIG. 8 is provided with a plurality of ladder-like members 44 in which steel pipes are combined vertically and horizontally between the pillars 3, and the end portions of the ladder-like members 44 are fixed to the pillars 3. It is comprised by. The ladder-like member 44 includes a pair of beam members 44a that are bridged between the columns 3 and a vertical member 44b that connects the beam members 44a at a predetermined interval. In the case of the snow receiving portion 43 having such a configuration, since the beam members 44a extending in the horizontal direction are joined together by the vertical members 44b, the strength of the entire snow receiving portion 43 is improved. Further, since the gap between the beam members 44a is divided into small pieces by the vertical members 44b, a small snow lump can be held. In the avalanche prevention fence shown in FIG. 8, similarly to FIG. 7, a reinforcing beam member 49 may be provided between the upper ends of the columns 3 in order to reinforce the upper ends of the fence. When the ladder-shaped member 44 has sufficient strength of the avalanche prevention fence as a whole, the head of the column 3 may be set to the same height as the upper end of the ladder upper member 44 without providing the beam members 49.

  Moreover, the snow receiving part 45 shown by FIG. 9 is comprised by providing the grating | lattice-like grating | lattice-like grating panel 46 between the support | pillars 3 with multiple sheets. The grating panel 46 is made of steel or the like, has high strength, and can be drained. When the grating panel 46 is used, sufficient strength can be obtained and a small snow lump can be held because the gap is small. In the avalanche prevention fence shown in FIG. 9, similarly to FIG. 7, a reinforcing beam member 49 may be provided between the upper ends of the columns 3 in order to reinforce the upper ends of the fence. In addition, when the strength of the entire avalanche prevention fence is sufficient by the grating panel 46, the head of the column 3 may be set to the same height as the upper end of the ladder upper member 44 without providing the beam members 49.

  Similarly to the grating panel 46, the snow receiving portion 47 shown in FIG. 10 is configured by providing a plurality of punching metals 48 made of a metal plate with a large number of small holes between the support posts 3. Yes. The punching metal 48 is made of a steel material or the like, has a high strength, and can be well drained. When the punching metal 48 is used, sufficient strength can be obtained and a small snow lump can be held because the gap is small. Also in the avalanche prevention fence shown in FIG. 10, a reinforcing beam member 49 may be provided between the upper ends of the columns 3 in order to reinforce the upper ends of the fence as in FIG. 7. When the punching metal 48 has sufficient strength of the entire avalanche prevention fence, the head of the column 3 may be set to the same height as the upper end of the ladder upper member 44 without providing the beam members 49.

  Further, although not shown, expanded metal may be used instead of punching metal. Expanded metal is manufactured by forming many short slits in a thin steel plate and enlarging the opening of the slits by pulling the steel plate from both ends. Even when such an expanded metal is used, sufficient strength can be obtained and a small snow lump can be held because the gap is small.

  In the avalanche prevention structure 31 shown in FIG. 6 of the above embodiment, as an example of fixing one avalanche prevention fence, an example in which the extension portion 21 of the pedestal portion 2 is fixed on the small step S2 by the small step anchor bolt FB is shown. However, the present invention is not limited to one avalanche prevention fence, and two or more avalanche prevention fences may be fixed along the vertical direction of the slope.

  For example, as a modified example of the present invention, as in the avalanche prevention structure 51 shown in FIGS. 11 to 12, in a field where the snow accumulation depth is shallow, the scale of the avalanche fence work is small, and the slope S1 is weak, You may connect the two avalanche prevention fences 1 by extending the base part 2 along the up-down direction of surface S1. That is, the two avalanche prevention fences 1 arranged side by side along the vertical direction of the slope S1 share the pedestal portion 2 extending along the vertical direction of the slope S1. At predetermined positions on the pedestal portion 3, pillars 3 of each avalanche prevention fence 1 are erected, and a snow receiving part 4 is further provided between the pillars 3. The pedestal portion 2 is fixed to the slope S1 by a slope anchor bolt SB1. The slope anchor bolts SB1 are arranged at positions on the mountain side of the support column 3, respectively. In addition, in the avalanche prevention fence 1 of FIGS. 11 to 12, the mountain side end portion of the pedestal portion 2 has an extension portion 21 extending along the surface of the small step S <b> 2, and the extension portion 21 is L-shaped to prevent overturning. Together with the member 5, it is fixed to the ground G of the small step S2 by the small step anchor bolt FB. With such a structure, a plurality of avalanche prevention fences 1 can be collectively fixed on the slope using the small anchor bolts FB embedded in one small step S2.

  Further, like the avalanche prevention structure 52 according to another modification of the present invention shown in FIG. 13, instead of extending and commonizing the pedestal portions 3 of the multiple-level avalanche prevention fences 1, You may make it connect the base parts 3 by the connection material 53 extended along the up-down direction of slope S1. The connecting material 53 is made of, for example, a wire rope or a rod-shaped steel material. The pedestal portion 3 of the uppermost avalanche prevention fence 1 is connected to the L-shaped toppling prevention member 5 embedded on the small step S <b> 2 via a connecting member 54 and a bracket 55. Similarly to the connecting material 53, the connecting material 54 is made of a wire rope, a rod-shaped steel material, or the like. The L-shaped toppling prevention member 5 and the connecting bracket 55 are fixed to the ground G of the small step S2 by the small step anchor bolts FB. In such a structure shown in FIG. 13 as well, a plurality of avalanche prevention fences 1 can be collectively fixed on the slope using the small anchor bolts FB embedded in one small step S2. . In addition, in the structure shown in FIG. 13, the length of the flat pedestal portion 3 is short, so that it is not easily affected by the unevenness of the slope S1. That is, there are few restrictions by the state of slope S1 about installation of the avalanche prevention fence 1, and an installation freedom degree is improved correspondingly.

DESCRIPTION OF SYMBOLS 1 Avalanche prevention fence 2 Base part 2a Mountain side edge part 2b Valley side edge part 2c Mountain side part 2d Valley side part 3 Support | pillar 4,43,45,47 Snow receiving part 5 Fall prevention member 6 Biting part 7 Snow mounting part 8 Connection Part 21 Extension part 30, 31, 51, 52 Avalanche prevention structure S1 Slope S2 Snow on step A1 Snow on slope A2 Snow on step F1 Force on the slope pushing the avalanche prevention fence along the slope F2 Slope Snow load on

Claims (11)

An avalanche prevention structure comprising an avalanche prevention fence that prevents an avalanche from occurring on a slope, and an anchor bolt that fixes the avalanche prevention fence to the ground of the slope,
The avalanche prevention fence is
It has a shape that can be installed on a slope, and has a mountain side end and a valley side end, the mountain side end is arranged on the mountain side of the slope, and the valley side end is a valley of the slope. A pedestal arranged on the side,
A plurality of columns rising from the pedestal,
A snow receiving portion constructed between the columns and having a shape capable of receiving snow between the columns;
A connecting portion that connects the mountain side surface of the support column and the mountain side portion of the pedestal portion than the support column;
With
The column is disposed at a position closer to the valley end than the mountain end of the pedestal,
The part of the pedestal portion on the mountain side of the support column has a shape on which snow can be placed,
The anchor bolt has a lower part embedded in the slope ground and an upper part connected to the mountain end of the pedestal, thereby fixing the mountain end of the pedestal to the slope ground. avalanche prevention structure according to claim <br/> things are. The support column is raised from the valley side end of the pedestal,
The avalanche prevention structure according to claim 1. The pedestal portion further includes a bite portion that is provided so as to protrude toward the slope in a portion on the mountain side of the column, and has a shape that can bite into the ground of the slope.
The avalanche prevention structure according to claim 1 or 2. The biting portion is provided to protrude toward the slope at the mountain side end of the pedestal portion,
The avalanche prevention structure according to claim 3. A snow-mounting portion that extends along the width direction of the pedestal portion at a portion of the pedestal portion that is closer to the mountain side than the support column and that has a shape capable of placing snow piled on the mountain side of the support column;
The avalanche prevention structure according to any one of claims 1 to 4. The snow-carrying portion extends along the width direction of the pedestal at the mountain side end of the pedestal,
The avalanche prevention structure according to claim 5.   The pedestal portions are respectively arranged on both sides in the width direction of the avalanche prevention fence,
  The snow placing part connects the pedestal parts on both sides,
The avalanche prevention structure according to claim 5 or 6. A bite portion having a shape capable of biting into the ground of the slope, provided to protrude toward the slope in a portion of the pedestal portion on the mountain side of the column;
A snow-mounting portion that extends along the width direction of the pedestal portion in the mountain-side portion of the pedestal portion of the pedestal portion, and has a shape capable of placing snow piled on the hillside of the support column; and
The biting part and the snow-carrying part are integrally formed,
The avalanche prevention structure according to claim 1 or 2. The anchor bolt is fixed to the ground of the slope with the snow-carrying portion together with the mountain side end portion of the pedestal portion,
The avalanche prevention structure according to any one of claims 6 to 8. The avalanche prevention structure is used to prevent the occurrence of avalanches in the steps formed in the middle of the slope ,
The avalanche prevention fence is installed at a position that can receive the snow that protrudes toward the valley side of the small step continuously from the snow on the small step on the valley side of the small step. ,
The avalanche prevention structure according to any one of claims 1 to 9 . The pedestal portion has an extended portion that extends and extends along the surface of the small step at the mountain side end of the pedestal portion,
It further comprises a step fixing means for fixing the extended portion to the ground of the step.
The extension portion is fixed to the ground of the step by the step fixing means.
The avalanche prevention structure according to claim 10.

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