JP2014105460A - Snowslide energy dissipator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a snowslide energy dissipator capable of reducing the cost of manufacture and mitigating the impact of snowslide without being overturned or damaged.SOLUTION: A snowslide energy dissipator 1 is installed in a valley V and decreases energy of snowslide S. The snowslide energy dissipator 1 comprises: cable fixing parts 2 installed on opposing slopes G of the valley V, respectively; a plurality of cables 3 which are routed side by side at mutually different heights so as to extend across the valley V and of which both end portions are fixed to the cable fixing parts 2; and a net 4 which is installed across the valley V and supported by the cables 3. Further, the snowslide energy dissipator 1 comprises post supporting parts 6, and posts 5 which are supported by the post supporting parts 6 so as to swing at a downstream side in a direction B of travel of the snowslide S and include U bolts 22 for holding the cables 3 in such a manner that the heights of the cables are maintained and a sedimentation load of the snowslide applied from an upper side to the cables is retained.

Description

  The present invention relates to an avalanche reduction work that reduces the avalanche momentum flowing along a valley.

  Conventionally, various prevention fences have been proposed to prevent avalanches flowing along the slopes of mountains. For example, an avalanche / falling rock prevention fence described in Patent Document 1 includes a large and heavy retaining wall made of a concrete block to stop an avalanche.

JP 2008-255632 A

  There are avalanches that flow along the valleys that extend linearly downstream from the entire slope of the mountain. However, in order to reduce the avalanche momentum flowing along such a valley, when the prevention fence made of a large and heavy concrete block as described above is installed so as to cross the valley, the manufacturing cost is reduced. There is a problem that it is difficult.

  In addition, avalanche reduction works such as group piles with multiple pillars or piles standing on the ground have been proposed in the past, but in such a structure, pressure in the avalanche traveling direction acts sideways on the pillars. Then, a large moment is applied to the base portion of the support column, and the support column may fall or be damaged.

  The present invention has been made in view of the circumstances as described above, and can reduce the manufacturing cost and can reduce the avalanche impact without causing overturn or damage. The purpose is to provide.

  In order to solve the above-mentioned problems, the avalanche stress reducing device of the present invention is an avalanche stress reducing device that is installed in a valley and reduces the avalanche momentum, and is provided with cable fixings that are respectively installed on slopes facing the valley. And a plurality of cables arranged at different heights so as to extend in a direction crossing the valley, and both ends fixed to the cable fixing portion, and installed so as to cross the valley And a net supported by the cable.

  According to such a configuration, the avalanche flowing along the valley is received by the net and the cable supporting the net, so the manufacturing cost is significantly reduced compared to the case of installing a heavy-weight concrete retaining wall. Is possible. Moreover, since both ends of the cable are fixed to the cable fixing part installed in the valley, the pressure in the avalanche traveling direction can be elastically received by the tension of the cable. There is no risk that the members constituting the avalanche reduction work will fall or be damaged.

  At least one column support unit installed in the valley, and a column supported by the column support unit so as to be able to swing downstream in the advancing direction of the avalanche flowing along the valley, each of the cables And at least one strut having a holding portion for holding the cable so as to maintain the height of the cable and to receive a sinking load of the avalanche from above on the cable. preferable.

  According to such a configuration, by holding the cable by the support portion of the support column, it is possible to maintain the height of the cable and receive the avalanche sinking load from above on the cable. Thereby, it is possible to disperse the settling load applied to the cable to the support, and to prevent the cable from being pushed down and distorted by the settling load of snow.

  In addition, since the support column is supported by the support column so that it can swing to the downstream side in the advancing direction of the avalanche flowing along the valley, it is downstream when the support column receives impact and pressure in the advancing direction of the avalanche. It is possible to disperse the impact and pressure to the cable while swinging to the side, and as a result, it is possible to prevent the column from falling or breaking.

  It is preferable that the support columns are installed on slopes facing each other between the valleys, and the support columns are supported by the support columns.

  According to such a configuration, when the cable receives an avalanche sinking load, it can be received by the columns disposed on the slopes on both sides of the valley. As a result, even when the avalanche sinking load applied to the cable is large, the possibility that the cable is pushed down by the avalanche sinking load and distorted is reduced.

  The support columns are preferably supported by the support columns in a state where the support columns are inclined with respect to the vertical line so that the ends of the support columns face the center of the valley.

  In the middle of the valley, there is a large amount of snow, and in the vicinity there is a large avalanche sinking load on the cable, which tends to be distorted by the cable being pushed down. Therefore, in the above configuration, since the column is supported by the column support part installed on the slope facing the valley so that the tip of the column is inclined with respect to the perpendicular so as to face the center of the valley, In the vicinity, the distance between the ends of the support columns becomes narrow, so that even when the width of the valley is wide, when the cable receives the avalanche sinking load, it can be reliably dispersed and received on the support columns on both sides. As a result, even when the width of the valley is wide and the avalanche sinking load applied to the cable is large, the possibility that the cable is pushed down by the avalanche sinking load and distorted is reduced.

  It is preferable that the holding portion holds the cable so as to allow movement in a direction crossing the valley of the cable.

  According to such a configuration, when the cable receives pressure from the avalanche in the advancing direction of the avalanche, the cable bends in the advancing direction while moving in the direction crossing the valley without being restrained by the support portion of the support column. It is possible to reliably transmit the cable tension to the cable fixing portion.

  As described above, according to the avalanche reducing work of the present invention, the manufacturing cost can be reduced, and the impact of the avalanche can be reduced without causing the constituent members of the current reducing work to fall or break. .

It is a front view concerning one embodiment of an avalanche reduction work according to an embodiment of the present invention. It is an expanded sectional view of the connection part of the cable fixing | fixed part and cable of FIG. FIG. 2 is an enlarged view of a portion near the anchor bolt head portion of the cable fixing portion of FIG. 1. It is the IV-IV sectional view taken on the line of FIG. FIG. 5 is an enlarged view of the vicinity of a U bolt in FIG. 4. It is an enlarged view of the connection part of the support | pillar and support | pillar support part of FIG. It is a top view of the base plate for support | pillars of FIG. It is a side view of the base plate for support | pillars of FIG.

  Next, the avalanche reduction work 1 of the present invention will be described in more detail with reference to the drawings.

  1 is installed in the valley V and reduces the momentum of the avalanche S flowing along the valley V.

  The avalanche reduction work 1 is supported by a pair of cable fixing portions 2, a plurality of cables 3 (five in the example of FIG. 1) fixed to both ends of the pair of cable fixing portions 2, and each cable 3. A net 4, a support column 5 that supports a plurality of cables 3, and a support column support unit 6 that supports a base side end of the support column 5 in a swingable manner. In the example of FIG. 1, the column 5 supports four cables 3 except for the lowest stage. The lowermost cable 3 is less affected by the settling load F (see FIGS. 4 to 5) of the avalanche S, so that it is less likely to be greatly distorted downward by the settling load even if it is not supported by the support column 5. In the present invention, the settling load F of the avalanche S refers to a downward load generated when the snow is compacted in a state where the avalanche S is accumulated or when the snow sinks downward due to a cause such as melting snow.

  The cable fixing portions 2 are respectively installed on slopes G facing the valley V. As shown in FIGS. 1 to 3, the cable fixing unit 2 includes a frame 11 embedded in the ground of the slope G, and an anchor bolt 12 embedded in the ground of the slope G through the law frame 11. A fixing bracket 13 fixed to the head 12 a of the anchor bolt 12, a nut 14 that fastens the fixing bracket 13 to the surface of the normal frame 11, and a link 16 that connects the fixing bracket 13 and the cable 3. ing.

  The frame 11 is a concrete long and narrow pedestal, and is entirely or partially embedded in the ground of the slope G in a direction substantially along the direction in which the slope G extends.

  As shown in FIGS. 2 to 3, the anchor bolt 12 penetrates through the legal frame 11 at intervals along the longitudinal direction of the method frame 11 so that the head 12 a protrudes above the method frame 11. And embedded in the ground of the slope G. A male screw portion 12b is formed on the head portion 12a.

  As shown in FIGS. 2 to 3, the fixing bracket 13 includes a pair of upright plate portions 13 a erected on both sides of the head 12 a of the anchor bolt 12, and a washer portion that connects the pair of upright plate portions 13 a. 13b, and a shaft member 13c that is fixed at both ends to the pair of upright plate portions 13a and engages the link 16. The washer portion 13b has a through hole 13b1. By inserting the head 12a of the anchor bolt 12 into the through hole 13b1 and tightening the nut 14 from above the washer 13b, the fixed bracket 13 is pressed against the upper surface of the modulus frame 11. At the same time, the anchor bolt 12 is pulled toward the ground surface by the reaction force tightened by the nut 14.

  Note that the nut 14 may be fixed in advance to the washer portion 13b of the fixed bracket 13, and in this case, the nut 14 is rotated on the head 12a of the anchor bracket 12 by simultaneously rotating the fixed bracket 13 and the nut 14. It can be screwed into the threaded portion 12b.

  As shown in FIG. 3, the shaft member 13 c includes a bolt 13 c 1, a nut 13 c 2 that is screwed to the bolt 13 c 1, and a cylinder portion 13 c 3 that covers a part of the male thread portion of the bolt 13 c 1. The cylinder part 13c3 is arrange | positioned between a pair of standing board parts 13a in the state engaged with the link 16, as FIG. 2 shows. The bolt 13c1 is inserted into the cylindrical portion 13c3 while penetrating the pair of standing plate portions 13a. The nut 13c2 is screwed to the front end portion of the bolt 13c from the outside of the pair of standing plate portions 13a.

  The link 16 is formed of an elliptical metal ring and has a tensile strength that can withstand the impact load of the avalanche S. As shown in FIG. 2, the link 16 is engaged with the cylindrical portion 13 c 3 of the shaft member 13 c between the pair of standing plate portions 12 a of the fixed bracket 13.

  As shown in FIG. 1, the plurality of cables 3 are arranged side by side at different heights so as to extend in a direction A crossing the valley V. Both end portions of each cable 3 are fixed to the links 16 connected to the fixing bracket 13 of the cable fixing portion 2 as described above. When the end portion of the cable 3 is connected to the link 16, for example, as shown in FIG. 2, the end portion of the cable 3 can be easily connected by connecting via a shackle 17. The shackle 17 includes a ring-shaped main body 17a whose one end is open, and a closing pin 17b that closes an open portion of the main body 17a. The main body 17a has an arc-shaped portion 17a1 and a pair of opposed portions 17a2. After fixing the end portion of the cable 5 to the main body 17a of the shackle 17, a part of the link 16 is inserted inside the arc-shaped portion 17a1 of the main body 17a, and then a gap between the pair of opposed portions 17a2 of the main body 17a is formed. By closing with the closing pin 17b, the cable 5 and the link 16 can be connected.

  Note that the end of the cable 3 may be directly connected to the link 16.

  As shown in FIG. 1, the net 4 is installed so as to cross the valley V and is supported by each cable 3. The net 4 is connected to each cable 3 by a conventionally known connecting means such as a splicing rope made of a thin steel wire not shown. The net 4 is made of, for example, a high-strength wire net that can withstand falling rocks.

  The net 4 has a height between the uppermost cable 3 and the lowermost cable 3, and has a trapezoidal shape that can cover both ends of each cable 3. Thereby, the net 4 can be covered so as to cross the valley V.

  The support columns 6 are respectively installed on slopes G facing the valley V.

  The support column support 6 includes a base 26 installed on the ground surface of the slope G, an angle adjusting member 27 installed on the base 26, and a base plate 28.

  As shown in FIG. 6, the base portion 26 includes an upper portion 26 a disposed on the upper surface side of the modulus frame 11 and a lower portion 26 b disposed on the lower surface side of the modulus frame 11. The upper part 26 a and the lower part 26 b are each made of concrete and are integrally formed with the frame 11. Note that the base 26 may be a member separate from the frame 11. Moreover, the shape of the base part 26 should just be a shape which can receive the settling load of the support | pillar 5 and the avalanche S concerning it.

  The upper part 26a has a horizontal surface 26a1. An angle adjusting member 27 is installed on the horizontal surface 26a1.

  As shown in FIG. 6, the angle adjusting member 27 has an inclined surface 27 a serving as a reference surface for setting the inclination angle of the support column 5 on the upper surface side. The inclined surface 27a is inclined with respect to the horizontal surface 26a1 of the base portion 26 so as to face the center of the valley V.

  5-7, the base plate 28 is being fixed on the inclined surface 27a of the angle adjustment member 27 in the state inclined from the horizontal surface 26a1. The base plate 28 includes a bottom plate portion 28a and a pair of upright plate portions 28b provided upright from the bottom plate portion 28a. The pair of upright plate portions 28b are spaced apart from each other in a direction A (see FIG. 6) crossing the valley V.

  The bottom plate portion 28a is fixed on the inclined surface 27a of the angle adjusting member 27 by being sandwiched by a pair of nuts 19 from above and below in the head portion 18a of the anchor bolt 18 embedded in the ground of the slope G.

  The support 5 is supported by the support 6 so that it can swing downstream in the traveling direction B (see FIG. 4) of the avalanche S flowing along the valley V, and the cable 3 is maintained at the height of the cable 3. And it hold | maintains so that it may hold | maintain so that the settling load F (refer FIGS. 4-5) of this avalanche S may be received with respect to the said cable 3 from the upper direction.

  Specifically, as shown in FIGS. 4 to 6, the support column 5 includes a support column body 21 that is swingably supported by the base plate 28 of the support column support portion 6, and a space in the longitudinal direction between the support column body 21. And a U-bolt 22 for holding the installed cable 3. The U bolt 22 corresponds to the holding portion of the present invention.

  The column main body 21 is made of a long rod-shaped body, for example, H-shaped steel. A pair of connecting plates 21 a are provided at the lower end of the column main body 21 so as to protrude downward. The pair of connecting plates 21a are spaced apart in a direction A (see FIG. 6) that crosses the valley V. The pair of connecting plates 21a is rotatably supported by the shaft member 25 with respect to the pair of standing plate portions 6c2 of the base plate 6c. As a result, as shown in FIG. 4, the support column 5 is supported by the support column support portion 6 so that it can swing around the shaft member 25 as the rotation center on the downstream side in the traveling direction B of the avalanche S flowing along the valley V. The

  Further, the base plate 28 that supports the column main body 21 in a swingable manner is fixed on the inclined surface 27a of the angle adjusting member 27 in an inclined state so as to face the center of the valley V from the horizontal surface 26a1. As shown in FIG. 4, the support column 5 is disposed so as to be inclined so that the tip 5a thereof faces the center of the valley V.

  4 to 5, the U-bolt 22 supports the cable 3 at a preset height of the cable 3 on the side surface 21b facing the upstream side in the advancing direction B of the avalanche S in the column main body 21. It is fixed by a nut 23 at a possible position.

  As shown in FIG. 5, the cable 3 is inserted into a through hole 24 that opens in a direction crossing the valley V formed by the U bolt 22 and the side surface 21 b of the column main body 21. Thereby, the U bolt 22 receives each cable 3 from below and holds it so as to maintain the height of the cable 3. Moreover, the U-bolt 22 can receive an avalanche settling load F (see FIGS. 4 to 5) applied to the cable 3.

  In addition, as shown in FIG. 5, the through hole 24 is set to have a width larger than the outer diameter of the cable 3, so that the cable 3 inserted into the through hole 24 crosses the valley V. Movement to A (see FIG. 1) is possible.

  As shown in FIG. 1, the pillars 5 are respectively supported by the above-mentioned pillar support portions 6 in a state where the tip 5 a is inclined by an angle θ with respect to the perpendicular VL so as to face the center of the valley V. This inclination angle θ is determined by conditions such as the width of the valley V and the length of the column 5 so that the uppermost cable 3 is divided into approximately three divisions by the uppermost U bolts 22 of the pair of columns 5. It is set as appropriate in consideration. Thereby, it is possible to disperse the settling load F of the avalanche S applied to the uppermost cable 3 to the cable fixing portions 2 and the pair of columns 5 on both sides in the valley V almost evenly.

  In the avalanche reduction work 1 configured as described above, when the avalanche S travels in the valley V along the traveling direction B, as shown in FIGS. The impact and pressure are received by the net 4 and the cable 3 that supports the net 4. The impact and pressure transmitted to the cable 3 are transmitted from both ends of the cable 3 to the cable fixing portion 2 embedded in the valley V, and can be received by the cable fixing portion 2.

  Further, the cable 3 is held by the U bolt 22 of the support column 5 so as to maintain the height of the cable 3. Moreover, when the avalanche S melts down and a downward settling load F acts on the cable 3, the settling load F can be received by the support 5. Thereby, it is possible to disperse the settling load F applied to the cable 3 to the support 5 and prevent the cable 3 from being pushed down and distorted by the settling load F of the avalanche S.

  In particular, in this embodiment, the support column 5 is supported by the support column support portion 6 installed on the slope G facing the valley V so that the tip of the support column 5 is inclined with respect to the perpendicular VL so as to face the center of the valley V. Therefore, in the vicinity of the center of the valley V, the interval between the ends of the columns 5 becomes narrow. Therefore, even when the width of the valley V is wide, the columns 5 on both sides when the cable 3 receives the settling load F of the avalanche S. It is possible to receive in a distributed manner.

  Moreover, since the support | pillar 5 is supported so that it can rotate to the periphery of the shaft member 25 with respect to the support | pillar support part 6 so that it can rock | fluctuate to the downstream of the advancing direction B of the avalanche S flowing along the valley V, avalanche When the strut 5 receives an impact and pressure in the traveling direction B of S, the strut 5 swings in the counterclockwise direction C in FIG. It is possible to disperse the impact and pressure to 3, and as a result, it is possible to prevent the support column 5 from falling or being damaged.

(Feature)
(1)
Since the avalanche reduction work 1 of the present embodiment configured as described above has a structure in which the avalanche S flowing along the valley V is received by the net 4 and the cable 3 that supports the net 4, it is made of heavy concrete. Compared with the case where the retaining wall is installed, the manufacturing cost can be greatly reduced. Moreover, since both end portions of the cable 3 are fixed to the cable fixing portion 2 installed in the valley V, the pressure in the traveling direction B of the avalanche S can be elastically received by the tension of the cable 3. As a result, there is no possibility that the members constituting the avalanche reduction work such as the columns and piles will fall over or be damaged as in the prior art.

(2)
In addition, in the avalanche reduction work 1 of the present embodiment, the height of the cable 3 is maintained by holding the cable 3 by the U bolts 22 that are spaced apart in the length direction of the column main body 21 in the column 5. The avalanche sinking load F is applied to the cable 3 from above. Thereby, it is possible to disperse the settling load F applied to the cable 3 to the support column 5 and to prevent the cable 3 from being pushed down and distorted by the settling load F of the avalanche S.

  In addition, since the column 5 is supported by the column support 6 so as to be able to swing downstream in the traveling direction of the avalanche S flowing along the valley V, the impact and pressure in the traveling direction B of the avalanche S are applied to the column. When receiving 5, it is possible to disperse the impact and pressure to the cable 3 while swinging downstream, and as a result, it is possible to prevent the support column 5 from being overturned or damaged.

(3)
In the avalanche reduction work 1 of the present embodiment, since the columns 5 are respectively arranged on the slopes G facing the valley V, the slopes on both sides of the valley V when the cable 3 receives the sink load F of the avalanche S are applied. It can be received by the arranged pillars 5. As a result, even when the settling load F of the avalanche S applied to the cable 3 is large, the possibility that the cable 3 is pushed down and distorted by the settling load F of the avalanche S is reduced.

  Moreover, if the support | pillar 5 and the support | pillar fixing | fixed part 6 are each installed in the slope G which the valley V opposes, it will become difficult to receive the influence of the water and snow which accumulate in the bottom of the valley V, and has an advantage that installation work becomes easy.

(4)
In the avalanche reduction work 1 of the present embodiment, the support column 5 is installed on the slope G facing the valley V so that the tip of the support column 5 is inclined with respect to the vertical line VL so as to face the center of the valley V. 6, since the gap between the ends of the columns 5 is narrow near the center of the valley V, even when the cable 3 receives the settling load F of the avalanche S even when the width of the valley V is wide. It is possible to reliably receive it on the columns 5 on both sides. As a result, even when the width of the valley V is wide and the avalanche sinking load F applied to the cable 3 is large, the possibility that the cable 3 is pushed down by the sinking load F of the avalanche S and is distorted is reduced.

(5)
In the avalanche reduction work 1 of this embodiment, when the cable 3 receives a pressure in the advancing direction C of the avalanche S from the avalanche S, the cable 3 is not restrained by the U bolts 22 of the support columns 5 and has a valley V. The moving direction C can be bent while moving in the transverse direction, and the tension of the cable 3 can be reliably transmitted to the cable fixing portion 2.

(Modification)
(A)
In the above embodiment, an example is shown in which the support column 5 and the support column fixing portion 6 are respectively installed on the slope G facing the valley V, but the present invention is not limited to this, and at least in the valley V One strut 5 and a strut fixing part 6 may be installed. Therefore, the column 5 and the column fixing part 6 may be installed only on one slope G of the valley V, or the column 5 and the column fixing unit 6 may be installed at the bottom of the valley V. Also in these cases, as in the above embodiment, it is possible to prevent the cable 3 from being distorted by being pushed downward by the sinking load F of the avalanche S, and to prevent the support column 5 from being overturned or damaged. It is.

(B)
Furthermore, although the avalanche reduction work 1 of the said embodiment is provided with the support | pillar 5 and the support | pillar fixing | fixed part 6, you may abbreviate | omit these support | pillar 5 and the support | pillar fixing | fixed part 6, and in that case, it follows along the valley V. By receiving the avalanche S flowing through the net 4 and the cable 3 that supports the net 4, it is possible to significantly reduce the manufacturing cost compared to the case of installing a heavy concrete retaining wall, And it is possible to suppress the possibility that the members constituting the avalanche reduction work will fall or be damaged.

(C)
In the above-described embodiment, the U bolt 22 is described as an example of the holding portion of the support column 5 that holds each cable 3, but the present invention is not limited to this, and each cable 3 is Various types of holding portions can be employed as long as the height of the cable 3 is maintained and the cable 3 is held so as to receive the avalanche sinking load F from above. . Therefore, in addition to the U-bolt, it may be a member having an open groove on the upper side. In this case, each cable 3 is received from below by inserting a cable into the groove. The height of the cable 3 can be maintained, and the cable 3 can be held so as to receive the avalanche settling load F from above.

DESCRIPTION OF SYMBOLS 1 Avalanche reduction 2 Cable fixing part 3 Cable 4 Net 5 Post 6 Post support part 21 Post body 22 U bolt (holding part)
B Traveling direction G Slope S Avalanche V Valley

Claims (5)

An avalanche mitigator installed in the valley to reduce the avalanche momentum,
Cable fixing portions respectively installed on the slopes facing the valleys;
A plurality of cables that are arranged side by side at different heights so as to extend in a direction crossing the valley, and both ends are fixed to the cable fixing part,
A net installed across the valley and supported by the cable;
An avalanche reducer characterized by having At least one support column installed in the valley;
The struts supported by the strut support portion so as to be able to swing to the downstream side in the advancing direction of the avalanche flowing along the valley, and maintaining the height of each of the cables, and The avalanche reduction device according to claim 1, further comprising at least one strut having a holding portion for holding the cable so as to receive a sinking load of the avalanche from above on the cable. The support columns are respectively installed on the slopes facing the valleys, and the support columns are supported by the support columns, respectively.
The avalanche reduction work according to claim 2. The struts are supported by the strut support portions in a state inclined with respect to the vertical line so that the front ends thereof are directed to the center of the valley.
The avalanche reduction work according to claim 3. The holding portion holds the cable so as to allow movement in a direction crossing the valley of the cable;
The avalanche reduction work according to claim 2.

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