JP2020012249A - Erection structure for post in guard fence - Google Patents

Abstract

To provide an erection structure for a post in a guard fence capable of relieving stress concentration on a lower part of a post at the time of receiving an impact, suppressing early deformation and buckling of the post, and sufficiently exhibiting the impact absorption performance inherent in a guard fence.SOLUTION: A lower part of a post 10 is erected on a slope face G via a ground plate 30. The ground plate 30 is slidably fixed to a ground plate anchor 42 through a plurality of slide holes 33 formed in the ground plate 30. The lower part of the post 10 is erected together with the ground plate 30 so as to be slidable in a specific direction of the slope face G at the time of receiving an impact.SELECTED DRAWING: Figure 2

Description

  TECHNICAL FIELD The present invention relates to a protective fence erected on a slope or a skirt of a hillside to catch fallen objects such as rockfall, earth and sand, and avalanches. The erecting structure of the pillars in

In general, a protective fence is basically composed of a plurality of pillars standing on slopes and the like at intervals, and a protective net attached between adjacent pillars. The cushioning device is interposed in a part of the rope material and a part of the stay rope supporting the column.
Most of the protective nets are made of wire mesh, metal or fiber ropes, or a combination of these. The supports are made of steel such as H steel or steel pipe, concrete-filled steel pipe, concrete-filled steel pipe with PC material embedded, etc. The materials used for the protective nets and columns are selected according to the shock absorbing performance of the protective fence.

In general, a protective fence is a structure that finally receives the impact force of a fallen object such as a falling rock acting on a protective net on a pillar, so the standing structure of the pillar becomes important.
As a standing structure of the support pillar, there are known a form in which the support is not tiltable and a form in which the support is tiltable.
As a form in which the column is erected so that it cannot be tilted, a form in which the lower part of the column is pierced into a concrete foundation (Patent Document 1) and a form in which the column is buried deep in the ground under the ground (Patent Document 2) are known. .
The configuration in which the column is tiltably erected is a structure in which the column is tiltably mounted on the ground plate without inserting the column, and a configuration in which a hinge element is provided below the column (Patent Documents 3 and 4). This is a form in which a holding rope is connected to an anchor for a strut driven into the inside, and a buffer metal fitting is provided at an end of the holding rope which is inserted into a ground plate and a hollow strut and is led out to the upper end of the strut (Patent Document 5).
In the form in which the hinge element is provided at the lower part of the support, a buffer device is interposed in a part of the support stay rope, and the support stay rope usually maintains the upright state of the support, and the support stay When the stay rope slips, the strut tilts toward the valley side around the hinge element.

JP-A-2003-34912 (FIG. 2) JP 2007-205109 A (FIGS. 1 and 3) JP 2007-32032 A (FIGS. 1 and 2) JP 2009-144472 A (FIGS. 1 and 7) JP 2001-107321 A (FIG. 3)

Conventional protective fences have the following problems to be solved.
<1> As disclosed in Patent Literatures 1 and 2, in a protective fence in which a column is erected so as not to be tilted, the base of the column is fixed so as not to be displaceable to withstand an impact force, and transmitted to the column. The structure is designed to receive a constant impact force at a fixed position.
Therefore, the transmission time of the impact force transmitted from the protective net to the support is extremely short, and the impact force acts instantaneously on the support, so that the base of the support before the protective fence exhibits the inherent shock absorption performance It suddenly bends and cannot fully demonstrate shock absorption performance.
<2> In the protective fence disclosed in Patent Literatures 3 and 4 in which the column is tiltable, the column is tilted at the time of receiving, but the impact force instantaneously acts on the base of the column. In addition, the shock absorbing performance inherent in the protective fence cannot be sufficiently exhibited.
<3> A general flexible protective fence is provided with a plurality of shock absorbers, and is configured to absorb an impact force when the shock absorber operates.
The use of a plurality of shock absorbers improves the shock absorbing performance of the guard fence, but requires replacement or maintenance of the deformable member after receiving the shock.

  The present invention has been made in order to solve the above problems, and its purpose is to reduce the concentration of stress on the lower part of the strut at the time of impact, thereby suppressing the early deformation and buckling of the strut. It is another object of the present invention to provide an erecting structure of a pillar in a protective fence, which can sufficiently exhibit the shock absorbing performance inherent in the protective fence.

The present invention includes a plurality of pillars standing at intervals and a protective net stretched between the pillars, and a lower part of the pillars stands on a slope via a grounding plate. The lower part of the support is erected along with the ground plate so as to be slidable in a specific direction of the slope.
In another aspect of the present invention, a plurality of slide holes are formed in the ground plate, and the ground plate is slidably fixed to the same number of ground plate anchors as the slide holes through the plurality of slide holes. .
In another embodiment of the present invention, the plurality of slide holes are parallel to each other and may be formed along a slope direction of the slope, or may be formed along a direction orthogonal to the slope direction of the slope. Alternatively, it may be formed along the oblique direction of the slope.
In another embodiment of the present invention, the support and the ground plate may be of an assembling type, or the support and the ground plate may be pre-assembled integrally.
In another embodiment of the present invention, the protective net is attached between adjacent columns in span units.

According to the present invention, the lower part of the column is erected so as to be slidable together with the ground plate in a specific direction of the slope, so that the lower part of the column can be slid at the time of impact, so that stress concentration on the lower part of the column can be reduced.
Therefore, it is possible to suppress early deformation and buckling of the column, and it is possible to sufficiently exhibit the shock absorbing performance inherent in the protective fence.

A perspective view of a protective fence according to the present invention, with a part thereof omitted. FIG. 3 is an exploded view of a support and a ground plate according to the first embodiment of the present invention. Longitudinal cross-section of support and ground plate It is explanatory drawing of a support | pillar and a grounding plate, (A) is a top view of the grounding plate which partly fractured, (B) is sectional drawing of BB in (A). Explanatory drawing of the trapping action of falling objects by the guard fence, and a plan model diagram of the guard fence before the support column slides Explanatory drawing of the trapping action of falling objects by the guard fence, and a plan model diagram of the guard fence when the support slides FIG. 4 is a plan view of a ground plate according to a second embodiment in which a slide hole is formed in the Y direction of the slope. Example 3 A plan view of a ground plate according to a third embodiment in which a slide hole is formed obliquely.

Hereinafter, the present invention will be described with reference to the drawings.
In the description, the inclination direction of the slope G is defined as Y direction, and the direction orthogonal to the inclination direction of the slope G is defined as X direction.

[Example 1]
<1> Outline of Protective Fence Referring to FIG. 1, the present invention provides a plurality of supports 10 (intermediate supports, terminal supports) erected at predetermined intervals, and a protection net stretched between the supports 10. It is assumed that a protective fence equipped with
Describing the protective fence exemplified in this example, each support 10 is erected on a slope G via a ground plate 30.
The lower part of the column 10 is slidable together with the ground plate 30 in a specific direction of the slope G. In this example, a form in which the support 10 slides in the X direction of the slope G will be described.
The slide structure of the column 10 will be described later.

A rope net 21 made of rope and a wire net 22 having a smaller mesh than the rope net 21 are superimposed and bridged between the plurality of columns 10. The rope net 21 and the wire net 22 constitute a protection net 23.
Both ends of the upper and lower horizontal ropes 21 a and 21 b constituting the rope net 21 are connected to adjacent columns 10 and 10.
The rope net 21 may be attached on a per-span basis of the support, or may be mounted on three or more supports 10. In either case, the left and right sides of the adjacent rope net 21 are connected by a separate connecting member (rope or the like) so that the joint does not open.

Further, a spacing rope 24 made of rope is routed between the upper portions of the adjacent pillars 10, 10, and the spacing rope 24 arranged in span units keeps the spacing between the neighboring pillars 10, 10 constant. It is possible to do.
The wire netting 22 may be attached to the spacing wire 24 so as to hang down, or may be attached to the rope net 21.

A mountain-side anchor 40 is provided immediately above each column 10 or between adjacent columns 10, and a side anchor 41 is provided beside the column 10 of the terminal.
Known anchors such as ground anchors and lock bolts are applied to these anchors 40 and 41.

A mountain side stay rope 45 is routed between the upper part of each support 10 and the mountain side anchor 40, and a mountain side positioning rope 46 is routed between each ground plate 30 and the mountain side anchor 40.
A side stay rope 47 is routed between the upper portion of the terminal post 10 and the side anchor 41, and a side positioning rope 48 is routed between the lower portion of the terminal post 10 and the side anchor 41. Have been.

  In this example, a description will be given of a type of protective fence in which the retaining ropes 45 and 47 and the horizontal ropes 21a and 21b constituting the rope net 21 are not provided with a known buffer metal. It is.

<2> Pillars Referring to FIGS. 2 to 4, the pillar 10 is moored around the outer peripheral surfaces of the upper and lower portions thereof by winding the spacing rope 24, the stay ropes 45 and 47, and the positioning rope 48 shown in FIG. A locking pin 11 for protruding is provided.
The connecting means of the plurality of ropes is not limited to the mooring type using the stopper pin 11, but may be connected to a bracket (not shown) projecting from the support post 10.

  In this example, a description will be given of a form in which the column 10 is formed of a hollow pipe (such as a steel tube). Is included.

<3> Grounding Plate The grounding plate 30 is a load transmitting plate for transmitting the load acting through the column 10 to the slope G and supporting it while positioning the lower portion of the column 10.
On the upper surface of the grounding plate 30, an outer cylinder 31 into which the lower part of the column 10 can be inserted is protrudingly provided. 32 are provided.
The outer cylinder 31 is reinforced by reinforcing ribs 34 arranged radially.
By inserting the lower part of the support 10 into the rubber plate 32 and fitting it, the lower part of the support 10 can be assembled to the ground plate 30.
The outer cylinder 31 and the rubber plate 32 may be in the form of a complete cylinder, or may be in a divided form in which the cylinder is vertically divided as shown.

  In this example, in order to improve the transportability of materials to the site and the workability at the site, a description will be given of an embodiment in which the support 10 and the ground plate 30 are constructed in an assembled manner. The connection may be made by fixing means such as screwing or screwing.

  In this example, one end of the mountain-side positioning rope 46 is connected to the connection hook 36 attached to the ground plate 30. However, even if one end of the mountain-side positioning rope 46 is directly moored and connected to the lower part of the column 10, it is connected. Good.

<4> Tension structure between support and ground plate Referring to FIGS. 2 to 4, the support 10 is in a tension state between the support 10 and the ground plate 30 via a tension member 50 penetrating the inside of the support 10. Are connected by
The tension member 50 is a rope member that can be inserted into the inside of the support column 10, and a lower portion thereof is moored with a suspension hook 35 provided upright on the ground plate 30, which is the bottom surface of the outer cylinder 31.
A tightening bolt 51 is integrally connected to the upper part of the tension member 50, and a tightening nut is attached to the tightening bolt 51 through which an annular contact plate 52, which is placed in order on the upper end of the column 10, and a spring 53 is inserted. 54 is screwed.
By tightening the tightening nut 54 to tension the tension member 50, the column 10 and the ground plate 30 are tightly connected to each other, so that the column 10 is held upright with respect to the ground plate 30.
The grounding plate 30 may be laid directly in contact with the slope G. However, if the grounding plate 30 is placed on the height adjusting mortar layer 44 constructed prior to the slope G, the stability and the bearing effect of the grounding plate 30 are improved. Will be better.

<5> Sliding Structure of Ground Plate The ground plate 30 is fixed to the slope G so as to allow the slope G to slide in the X direction at the time of receiving. The slide structure of the ground plate 30 will be described in detail with reference to FIGS.

<5.1> Sliding Holes of Grounding Plate The sliding structure of the grounding plate 30 will be described. A plurality of sliding holes 33 are formed on the plate surface of the grounding plate 30 with the outer cylinder 31 interposed therebetween. The plurality of slide holes 33 are in parallel with each other, and are arranged in parallel with the X direction of the slope G.
Since the sliding distance of the ground plate 30 is determined by the total length of the slide hole 33, the total length of the slide hole 33 is appropriately selected in consideration of the shock absorbing performance of the protective fence, the installation status at the site, and the like.

<5.2> Ground Plate Anchor The ground plate anchor 42 for fixing the ground plate 30 is a known anchor such as a lock bolt, and is provided at a plurality of locations along the Y direction of the slope G.
The number of the ground plate anchors 42 may be the same as the number of the slide holes 33.
The ground portion of the ground plate anchor 42 is formed with a screw so that the nut 43 can be screwed therein, and the nut 43 is screwed into the exposed screw portion of the ground plate anchor 42 inserted through each slide hole 33. Thus, the ground plate 30 can be fixed to the slope G.

[Behavior of protective fence]
With reference to FIGS. 5 and 6, the behavior of the protective fence at the time of receiving, in particular, the behavior of the column 10 will be described. In addition, the basic trapping action of the fallen object such as a falling rock on the protective fence is the same as that of the related art, and the description thereof is omitted here.

<1> Behavior of Posts Immediately After Receiving FIG. 5 is a plan view showing a model of the protective fence immediately after the impact F of the collapsed object collides with the protective net 23. The slide hole 33 of each grounding plate 30 has a slope G. It is arranged parallel to the X direction.

Immediately after the impact F acts on the protection net 23, the protection net 23 starts to bend toward the valley side and starts to be deformed, and the impact F acts as a pulling force f on each of the adjacent columns 10, 10 through the protection net 23. I do. The tensile force acting on each column 10 acts on the ground plate 30 as a displacement force f toward the X direction of the slope G.
When the displacement force f of the slope G acting on the ground plate 30 in the X direction is smaller than the fixing force of the ground plate 30 fixed to the ground plate anchor 42, no displacement occurs in the ground plate 30. In other words, standing position of the strut 10 remains initially unchanged even span _{L 1} of adjacent struts 10, 10.
Therefore, the impact energy is absorbed by the deformation resistance of the protection net 23 and the strength of the column 10 as in the conventional protection fence.

<2> Sliding of pillars FIG. 6 is a plan model diagram of the protective fence when the amount of deformation of the protective net 23 increases.

When the amount of deformation of the protection net 23 increases, the displacement force f of the slope G acting on the ground plate 30 in the X direction also increases.
When the displacement force f of the slope G acting on the ground plate 30 in the X direction exceeds the fixing force of the ground plate 30 fixed to the ground plate anchor 42, the ground plate 30 moves along the slide hole 33. The inclined surface G slides in the X direction.
That is, to vertically position the struts 10 are laterally displaced from the initial position, the span L ₂ adjacent strut 10, 10 is slightly shorter than the span L ₁ before the displacement.

  Even while the lower part of the column 10 is displaced toward the X direction of the slope G, the energy of the shock absorber is continuously absorbed by the deformation resistance of the protection net 23 and the strength of the column 10.

As described above, according to the present invention, since the application time of the load on the support post 10 is elongated by causing the slide displacement of the support post 10 at the time of receiving, all of the impacts F are instantaneously applied to the adjacent support posts 10, 10. Working can be avoided.
The longer load acting time means that impact force is slowly applied to the column 10.
Therefore, not only can the pillar 10 fully exhibit the shock absorption performance originally possessed, but also the protection net 23 can fully exhibit the shock absorption performance.
In other words, stress concentration on the lower part of the support 10 can be reduced, and sudden bending of the base of the support 10 can be suppressed.

<3> Propagation action to adjacent span When a collapsed object collides with a part of the protection net 23, the protection net 23 located in the receiving range bends and deforms toward the valley side. Absorbs shock energy.
When the amount of deformation of the protection net 23 increases, when the adjacent struts 10, 10 are displaced in the approaching direction, they are also propagated to the strut 10 (not shown) through the protection net 23 located outside thereof and are sequentially drawn.
Therefore, even in a span in which no impact is received, it functions to absorb impact energy.

[Example 2]
Hereinafter, other embodiments will be described. In the description, the same portions as those in the above-described embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

With reference to FIG. 7, an embodiment in which the lower portion of the column 10 is slidably provided along the Y direction of the slope G will be described.
In this embodiment, a plurality of slide holes 33 are provided in the ground plate 30 along the Y direction of the slope G. The plurality of slide holes 33 are in parallel with each other as in the first embodiment.
The fixing of the ground plate 30 via the ground plate anchor 42 is the same as in the first embodiment.

  In the present embodiment, the lower part of the column 10 can slide along the Y direction of the slope G together with the pressing plate 30 at the time of receiving, and the sliding displacement of the column 10 at the time of receiving as in the first embodiment. With this, the concentration of stress on the lower portion of the column 10 can be reduced, and the impact absorbing performance inherent in the protective fence can be sufficiently exhibited.

[Example 3]
With reference to FIG. 8, an embodiment in which the lower part of the column 10 is slidably provided along the oblique direction of the slope G will be described.
In this embodiment, a plurality of slide holes 33 are provided in the ground plate 30 along the oblique direction of the slope G.

  In the present embodiment, the lower portion of the column 10 can slide along the oblique direction of the slope G together with the pressing plate 30 at the time of receiving, as in the first and second embodiments. With the slide displacement, the concentration of stress on the lower portion of the column 10 can be reduced, and the shock absorbing performance inherent in the protective fence can be sufficiently exhibited.

DESCRIPTION OF SYMBOLS 10 ... Support | pillar 11 ... Lock pin 21 ... Rope net 21a, 21b ... Horizontal rope material 22 ... Wire mesh 23 ... Protective net 24 ... Spacing holding cable 30 ... Contact Base plate 31, outer cylinder 32, rubber plate 33, slide hole 34, reinforcing rib 35, hanging hook 40, mountain-side anchor 41, side anchor 42, ground plate Anchor 43 ... Nut 45 ... Mountain side stay rope 46 ... Mountain side positioning rope 47 ... Side stay rope 48 ... Side positioning rope 50 ... Tension member 51 ... Tightening bolt 52 ... This plate 53 ... Spring 54 ... Tightening nut

Claims (8)

A plurality of pillars erected at intervals and a protective net stretched between the pillars, and a lower part of the pillar is a protective fence erected on a slope via a ground plate,
The lower part of the support is erected slidably together with the ground plate in a specific direction of the slope,
Standing structure of pillars on the fence.   A plurality of slide holes are formed in the ground plate, and the ground plate is slidably fixed to the same number of ground plate anchors as the slide holes through the plurality of slide holes. The standing structure of the support pillar in the protective fence according to 1.   3. The standing structure according to claim 2, wherein the plurality of slide holes are parallel to each other and formed along a slope direction of the slope. 4.   3. The standing structure according to claim 2, wherein the plurality of slide holes are parallel to each other and are formed along a direction perpendicular to a slope direction of the slope. 4.   3. The standing structure according to claim 2, wherein the plurality of slide holes are parallel to each other and are formed along an oblique direction of a slope. 4.   The standing structure of the support fence according to claim 1, wherein the support and the ground plate are assembled.   The upright standing structure of the support fence according to claim 1, wherein the support and the ground plate are assembled in advance integrally.   2. The standing structure of the protection fence according to claim 1, wherein the protection net is attached between adjacent columns in span units. 3.

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