Guard fence support structure

Abstract

To provide a support structure capable of absorbing impact energy even when impact force acts on any place of a support body, in the support structure of a guard fence in which the support body is installed on a sill serving as a foundation.SOLUTION: A support structure of a protective fence 10 comprises a base plate 40 which is placed on a sill and on which a support body is erected, and a guide mechanism for guiding the movement of the base plate and the support body on the sill from a mountain side to a valley side of a ground slope, the guide mechanism comprises a holding member fixed to the sill and holding the base plate with a predetermined holding force, a long hole formed in the holding member, and a penetrating member attached to the base plate and penetrating the long hole; the holding force of the holding member is such that the base plate and the support body can be guided by the guide mechanism to move to the valley side when the protective fence catches a fallen stone and a load of a predetermined value or more acts on the base plate to the valley side.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] The present invention relates to a support structure used in a protective fence that prevents disasters by catching collapsed earth and sand, falling rocks, etc. [Background technology]

[0002] Traditionally, protective fences have been installed on mountain slopes to protect adjacent roads, railways, and residences from natural disasters such as falling rocks, landslides, and avalanches. In particular, in earthquake-prone Japan, where falling rocks and landslides are likely to occur frequently on slopes due to earthquakes, it is extremely important to install protective fences and take measures against disasters.

[0003] Such protective fences generally include a plurality of posts erected on a structure or slope and a net stretched between the posts.

[0004] For example, the protective fence described in Patent Document 1 is formed by stretching a net between multiple posts erected on a ground slope, and each post is made of a highly rigid columnar body, and is erected by embedding the base of this columnar body into the ground. When an impact force acts on this protective fence due to a rockfall or the like, the impact energy is absorbed by the stretching of the net without deforming the posts.

[0005] In the protective fence described in Patent Document 1, the impact force not absorbed by the net is transmitted to the posts, and the posts are subjected to a resistance force from the surrounding ground that resists this impact force, resulting in a large load acting on the posts. To be able to withstand the large load without deformation, the base of each post needs to be buried deep into the ground and firmly fixed to a concrete foundation, which poses problems of long construction times and high costs. Furthermore, if the support pillar is damaged due to being unable to withstand the impact force, the concrete foundation must be destroyed to pull out the embedded support pillar and then the entire pillar must be replaced, which poses the problem of increased construction time and cost for the maintenance work on the pillar.

[0006] To solve this problem, Patent Document 2 discloses a guardrail support structure in which, rather than embedding the support posts, a column-shaped support body is erected via a hinge on a base constructed on the ground slope. The support body is prevented from tipping toward the valley by a stay rope stretched from the top end of the support body toward the mountain slope, and is also prevented from tipping toward the slope by a highly rigid rod-shaped body extending from the support body toward the mountain. The stay rope is equipped with a shock absorber that can absorb impact forces.

[0007] In the support structure described in Patent Document 2, the support body is not buried in the ground, making it easy to install and replace the support body, and significantly reducing the time and cost required for maintenance work when the support body is damaged. Furthermore, in a protective fence equipped with this support structure, when an impact force is applied by a rockfall or the like, the net extends to absorb the impact energy, and the support body can be tilted via a hinge to extend the stay rope supporting the support body, allowing the shock absorber attached to the stay rope to absorb the impact energy. In this way, tilting the support body itself reduces the load acting on the support and suppresses damage to the support. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-117361 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-105721 Summary of the Invention [Problem to be solved by the invention]

[0009] However, in the support structure described in Patent Document 2, when an impact load acts above the support body, the support body can be tilted significantly to effectively absorb the impact energy, but when a falling rock hits the lower end of the support body where the hinge is attached, force is applied to the fulcrum of the support body, so there is a problem in that the support body cannot be tilted to absorb the impact energy.

[0010] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a support structure for a protective fence in which the support body is installed on a foundation base, which is capable of absorbing impact energy regardless of where on the support body an impact force acts. [Means for solving the problem]

[0011] In order to achieve the above object, the support structure of the protective fence described in claim 1 comprises: A support structure for a protective fence that is installed on the ground at predetermined intervals to stretch a protective net, the support structure comprising a base constructed on the ground and a support body installed on the base, a substrate that is placed directly or indirectly on the base and has the support body erected on an upper surface; a guide mechanism that guides the movement of the base plate and the support pillar body on the base from the mountain side to the valley side of the ground slope, The guide mechanism includes: a clamping member fixed to the base and configured to clamp the substrate with a predetermined clamping force; a slot formed in the clamping member and extending from the crest side to the valley side; a penetrating member attached to the substrate and passing through the slot, The penetrating member moves along the extension direction of the long hole, thereby allowing the substrate and the support column body to move toward the valley side, The clamping force of the clamping member is The clamping force is such that when the protective fence catches a falling rock and a load of a predetermined value or more acts on the base plate toward the valley, the base plate and the main body of the support pillar are guided by the guide mechanism and can move toward the valley.

[0012] According to this configuration, since the support body is erected on the upper surface of the base plate, when a collision load acts on the support body due to a rockfall or the like, the collision load acts on the base plate via the support body toward the valley side of the ground slope. The base plate is not rigidly fixed to the base, but is designed so that when the collision load acting on the base plate exceeds a predetermined value, the base plate can move along the base toward the valley side of the ground slope in response to the impact load. Therefore, impact energy can be absorbed by the movement of the support body and the base plate. By making the entire support body movable relative to the base in this way, even if an impact load acts on any part of the support body in the vertical direction, the support body can be displaced relative to the base to mitigate the impact and absorb the impact energy.

[0013] The support structure according to claim 2 is the support structure according to claim 1, the clamping member is a clamping plate that is disposed parallel to the base and clamps the substrate in cooperation with the base, the penetrating member is the support column body erected on the substrate, or a hinge whose lower part is fixed to the substrate and whose upper part supports the support column body so that the support column body can tilt, The substrate is characterized in that it is clamped between the base and the clamping plate by screwing a nut onto an anchor bolt that protrudes from the base and penetrates the clamping plate, with the penetrating member penetrating the mountain-side end of the long hole.

[0014] With this configuration, when the impact load acting on the base plate exceeds a predetermined value, the base plate receives the impact load and moves along the slots formed in the clamping plates toward the valley side of the ground slope. This allows the support body to be displaced relative to the base plate to absorb the impact energy, regardless of whether the impact load acts on the support body in the vertical direction. Furthermore, the length of the slots can limit the distance the base plate can move.

[0015] The support structure according to claim 3 is the support structure according to claim 1, the clamping members are a pair of clamping plates that are disposed perpendicular to the base and clamp the substrate that is disposed perpendicular to the base, the penetrating member is a bolt that is attached to the base plate in a state where it penetrates the base plate, and both ends of the bolt penetrate the elongated holes of the pair of clamping plates, The substrate is characterized in that it is clamped between the pair of clamping plates by screwing a nut onto the bolt while the bolt passes through the crest side end of the long hole in the pair of clamping plates.

[0016] With this configuration, when the impact load acting on the base plate exceeds a predetermined value, the base plate receives the impact load and moves toward the valley side of the ground slope along the slots formed in the pair of clamping plates. As a result, regardless of whether the impact load acts on the support body in the vertical direction, the support body can be displaced relative to the base to absorb the impact energy. In addition, the length of the slots can limit the distance the base plate can move.

[0017] The support structure according to claim 4 is the support structure according to claim 2, The present invention is characterized by comprising a friction control plate disposed between the substrate and the base, which controls the frictional resistance between the substrate and the base.

[0018] According to this configuration, the friction control plate disposed between the substrate and the base can control the friction resistance when the substrate moves relative to the base.

[0019] The support structure according to claim 5 is the support structure according to claim 3, The present invention is characterized by comprising a friction control plate disposed between the substrate and the pair of clamping plates, for controlling the frictional resistance between the substrate and the pair of clamping plates.

[0020] According to this configuration, the friction control plate disposed between the substrate and the pair of clamping plates can control the frictional resistance when the substrate moves relative to the pair of clamping plates.

[0021] The support structure according to claim 6 is the support structure according to claim 3 or 5, The support column body is tiltably mounted on the base plate via a hinge.

[0022] With this configuration, when an impact force acts on the support column body, the support column body not only moves relative to the base but also tilts via the hinge, making it possible to absorb a larger impact energy. Also, the hinge can eliminate the moment acting on the board, making it easier to control the load acting on the board in the direction of movement.

[0023] The support structure according to claim 7 is the support structure according to any one of claims 1 to 6, The base is characterized by comprising a concrete foundation provided on a ground slope, and a metal reinforcing plate placed on the concrete foundation and on which the substrate is placed.

[0024] With this configuration, the base can be stabilized by forming it from a solid concrete foundation, and the surface of the base can be reinforced with a reinforcing plate, preventing the surface of the concrete foundation from collapsing due to the frictional force of the substrate when the substrate moves on the base.

[0025] The support structure according to claim 8 is the support structure according to any one of claims 1 to 7, The reinforcing plate is characterized in that one end is attached to the substrate and the other end is attached to a frame portion protruding upward from the outer peripheral edge of the reinforcing plate, and the reinforcing plate is provided with a biasing means that expands or contracts when the substrate moves toward the valley side, thereby biasing the substrate toward the mountain side.

[0026] With this configuration, when the substrate moves, the biasing means attached to the substrate expands and contracts, allowing the biasing means to absorb the movement energy of the substrate, i.e., the impact energy received by the support column body. In addition, the expansion and contraction force of the biasing means makes it easier to control the sliding load when the substrate moves, and maintenance after the substrate has moved is also easy. [Effects of the Invention]

[0027] According to the support structure of the protective fence of the present invention, the base plate on which the support body is erected is configured to be movable on the base along the long hole, so that when an impact load acts on the support body due to a rockfall or the like, the entire support body can be moved relative to the base to absorb the impact energy, regardless of whether the impact load acts on the top or bottom of the support body. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a perspective view of a protective fence equipped with a support structure according to the present invention. [Figure 2] FIG. [Figure 3] FIG. 2 is a cross-sectional view showing the main part of the support structure. [Figure 4] FIG. 2 is a plan view of the support columns seen from above, showing a state before the substrate is moved. [Figure 5] FIG. 10 is a plan view of the support columns seen from above, showing the state after the substrate has been moved. [Figure 6] FIG. 3 is a cross-sectional view similar to FIG. 2 showing a main part of a support structure according to a second embodiment. [Figure 7] FIG. 10 is a plan view of the support column of the second embodiment as seen from above. [Figure 8] FIG. [Figure 9] FIG. 10 is a perspective view of a protective fence equipped with a support structure of a third embodiment. [Figure 10] FIG. 10 is a cross-sectional view similar to FIG. 2 showing a main part of a support structure according to a third embodiment. [Figure 11] FIG. 10 is a plan view of the support column of the third embodiment, seen from above. [Figure 12] FIG. 10 is a side view of the protective fence of the third embodiment, illustrating the operation of the protective fence. [Figure 13] FIG. 10 is a cross-sectional view showing the main part of the support structure of the fourth embodiment. [Figure 14] FIG. 10 is a plan view of the support column of the fourth embodiment, seen from above. [Figure 15] FIG. 10 is a cross-sectional view showing the main part of the support structure of the fifth embodiment. [Figure 16] FIG. 16 is a cross-sectional view taken along line AA in FIG. [Figure 17] FIG. 10 is a plan view of the support pillar seen from above, showing a modified example of the support pillar structure having a breakable member. DETAILED DESCRIPTION OF THE INVENTION

[0029] (First embodiment) FIG. 1 is a perspective view of a protective fence 10 equipped with a support structure 1 according to a first embodiment of the present invention. Note that each drawing is a schematic diagram and does not precisely show the dimensions of each component. The protective fence 10 comprises a plurality of support posts 20 and a protective net 12 (hereinafter simply referred to as "net 12") stretched between the support posts 20, and the net 12 prevents damage by capturing falling rocks, collapsed earth and sand, etc. The height of the support posts 20 above ground is, for example, about 2 m to 5 m, and the spacing between the support posts 20 is, for example, 3 m to 5 m, or in some cases about 5 m to 10 m, and these are selected appropriately depending on the size of the slope on which the protective fence 10 is to be installed and the situation.

[0030] The protective fence 10 of this embodiment comprises multiple posts 20-1 to 20-4, a net 12, an auxiliary rope 14, and a buffer means 16 attached to the auxiliary rope 14. Note that while the illustrated example shows four posts 20-1 to 20-4, the number of posts 20 is not limited to this and may be two or more. The multiple posts 20 are installed in the ground at predetermined intervals to tension the net 12, forming a single post row. Each post 20 has a post structure 1 including a base 30, anchor bolts 36, a base plate 40 with elongated holes 42 formed therein, and a post body 22. Each of the components that make up the protective fence 10 will be described in detail below.

[0031] As shown in Fig. 1, the net 12 is a mesh of steel wires (for example, wires made of high-tensile hard steel wires or wires made by twisting multiple high-tensile hard steel wires together). The net 12 shown in the figure is a diamond-shaped wire mesh with diamond-shaped meshes, but is not limited to this, and various types of nets 12 can be used, such as a ring net made of wires formed into rings (for example, rings with a diameter of 300 to 400 mm).

[0032] The auxiliary ropes 14 are stretched at a predetermined height between at least two of the multiple pillars 20-1 to 20-4. The auxiliary ropes 14 are provided with buffer means 16 that allow the auxiliary ropes 14 to stretch within a predetermined range when a load is applied due to falling rocks or the like. As shown in FIG. 1 , in this embodiment, five auxiliary ropes 16 are stretched horizontally at intervals in the vertical direction between the two pillars 20-1 and 20-4 located at both ends of the pillar row. Each auxiliary rope 14 is stretched with a constant tension by fixing members 15 provided on the sides of the two pillars 20-1 and 20-4. Buffer means 16 are provided near both ends of each auxiliary rope 14.

[0033] 2, the buffer means 16 has a configuration in which the auxiliary ropes 14 are first passed through a metal tightening member 17 having a hole 17a through which two auxiliary ropes 14 can pass, and after the auxiliary ropes 14 are wound once in a loop, the auxiliary ropes 14 are again passed through the hole 17a from the same direction, and the tightening member 17 is crimped to fix the tightening member to the passed auxiliary ropes 14. This allows the auxiliary ropes 14 to be in frictional contact with each other within the hole 17a.

[0034] In a net 12 equipped with such buffer means 16, when the impact load from falling rocks is transmitted to the auxiliary ropes 14, the impact energy is absorbed by the friction generated within the holes 17a between the auxiliary ropes 14 and between the auxiliary ropes 14 and the fastening members 17. This action causes the annular portions of the buffer means 16 to contract in diameter, and the auxiliary ropes 14 are shifted toward the center of the protective fence 10 by the amount of the contraction, thereby increasing resistance to falling rocks. The size of the annular portions of the auxiliary ropes 14 can be changed as needed to obtain the desired buffering effect; if greater buffering effect is required, the annular portion can be made larger. Note that any buffering means can be used, not just the example shown in Figure 2.

[0035] As shown in Figures 3 and 4, the support pillar 20 has a support structure 1 including a base 30 constructed on the ground, a plurality of anchor bolts 36 with their tips protruding from the upper surface 30a of the base 30, a base plate 40 placed on the base 30, and a support pillar body 22 installed on the base 30 via the base plate 40. The base plate 40 is configured to be movable relative to the base 30 when subjected to a load equal to or greater than a predetermined value. Figure 4 and Figure 5, which will be described later, show a view from above with a portion of the base 30 cut away to make it easier to understand the movement of the base plate 40.

[0036] The base 30 serves as the foundation for the support pillar 20. In this embodiment, the base 30 is made of a concrete foundation 31 constructed on a ground slope. By forming the base 30 from a solid concrete foundation 31 in this way, the base 30 on which the support pillar body 22 is installed can be stabilized. A plurality of anchor bolts 36 are embedded and fixed in the concrete foundation 31. The plurality of anchor bolts 36 are arranged in accordance with the positions of a plurality of elongated holes 42 formed in the base plate 40. In this embodiment, the surface of the base 30 on which the base plate 40 is placed is formed as a substantially horizontal plane, but the surface of the base 30 may be inclined relative to the horizontal plane.

[0037] The base plate 40 is a plate material placed on the base 30, and has a plurality of elongated holes 42 through which the plurality of anchor bolts 36 pass. The base plate 40 can be made of a high-strength material, for example, a metal plate material such as a steel plate.

[0038] The multiple elongated holes 42 extend in the same direction so as to extend long from the mountain side of the ground slope toward the valley side when the substrate 40 is installed on the foundation 30. In this embodiment, as shown in FIG. 4, the support body 22 is erected in the center of the substrate 40, and four elongated holes 42 are provided around the support body 22 so as to surround the support body 22. The extension direction of the elongated holes 42 approximately coincides with the direction in which the substrate 40 receives an impact load due to falling rocks or the like via the support body 22. The number of elongated holes 42 is not limited to four, and may be two or more. Furthermore, it is preferable that the elongated holes 42 be provided on the mountain side and the valley side of the ground slope relative to the support body 22.

[0039] The longitudinal length of the elongated hole 42 can be, for example, 0.5 to 0.7 times the diameter of the support 22. The length of the elongated hole 42 is preferably 300 mm or less, and in this embodiment, the length of the elongated hole 42 is set in the range of 100 mm to 300 mm.

[0040] Furthermore, it is preferable that the length of the width direction of the elongated hole 42 (i.e., the length in the direction perpendicular to the longitudinal direction) is set to a size that allows some leeway with respect to the diameter of the anchor bolt 36, for example, 1.5 to 2 times the diameter of the anchor bolt 36. By allowing some leeway in the length of the width direction of the elongated hole 42 in this way, when the substrate 40 moves relative to the base 30, movement of the elongated hole 42 in the width direction as well as movement of the elongated hole 42 in the longitudinal direction can be permitted.

[0041] The pillar body 22 is a columnar body made of a highly rigid material such as steel, and is erected with its lower end fixed to the base plate 40. In this embodiment, the pillar body 22 has a square cross section, but the cross section is not limited to this and may be circular or another polygonal shape. In this embodiment, the lower end of the pillar body 22 is fixed to the base plate 32 by welding. The pillar body 22 in this embodiment is further supported by a highly rigid rod-shaped support member 24. One end of the support member 24 is joined to the upper surface of the base plate 40, and the other end is joined to the pillar body 22. The length of the pillar body 22 can be, for example, 1.5 m to 3.5 m.

[0042] The base plate 40 to which the support body 22 is fixed upright is fixed to the base 30 with each of the anchor bolts 36 passing through each of the elongated holes 42 and each anchor bolt 36 positioned at the valley-side end of each elongated hole 42. In this embodiment, the base plate 40 is fixed to the base 30 by tightening a fixing nut 37 onto each anchor bolt 36. This fixing force is set to a degree that allows the base plate 40 to move on the base 30 along the elongated holes 42 when the base plate 40 receives a load of a predetermined value or more on the valley side.

[0043] Next, we will explain the operation of the protective fence 10 having the above-mentioned support structure 1. When falling rocks or collapsed earth and sand occur and the protective fence 10 receives them, an impact load acts on the net 12 and the support poles 20.

[0044] In the protective fence 10 of this embodiment, the post body 22 is erected on the upper surface of the base plate 40. Therefore, when a collision load acts on the post body 22, the collision load acts on the base plate 40 via the post body 22 toward the valley side of the ground slope. As described above, the base plate 40 is not firmly fixed to the base 30, but is loosely fixed. Specifically, when the collision load acting on the base plate 40 exceeds a predetermined value, the base plate 40 is able to move on the base 30 along the elongated hole 42 toward the valley side of the ground slope in response to this impact load. Therefore, when the base plate 40 receives an impact load equal to or greater than the predetermined value, it moves on the base 30 together with the post body 22 toward the valley side, as shown in FIG. 5, thereby absorbing the impact energy of falling rocks, etc. In this way, in the pillar structure 1 of this embodiment, the entire pillar body 22 is designed to be movable relative to the base 30, so that even if an impact load acts on any part of the pillar body 22 in the vertical direction, the pillar body 22 can be displaced relative to the base 30 to absorb the impact energy.

[0045] (Second embodiment) Fig. 6 is a cross-sectional view showing the main part of the support structure of the second embodiment, and Fig. 7 is a plan view of the support structure of the second embodiment as seen from above. In Fig. 6 and Fig. 7, parts corresponding to those in the first embodiment are given the same reference numerals. In the second embodiment described below, detailed description of the same configuration as in the first embodiment will be omitted.

[0046] In the pillar structure 1 of this embodiment, the base 30 includes a concrete foundation 31 provided on a ground slope and a reinforcing plate 32 installed on the concrete foundation 31. The pillar structure 1 also includes a friction control plate 50 arranged between the base 30 and a base plate 40, a stopper member 52 fixed to the base 30, and a brake means 54 attached to the base plate 40.

[0047] The reinforcing plate 32 is placed on the concrete foundation 31 and forms the upper surface of the base 30 on which the substrate 40 is placed. The reinforcing plate 32 can be formed of a material with high surface friction strength, such as a metal plate such as a steel plate. The reinforcing plate 32 of this embodiment includes a flat main body 33 and a frame 34 protruding upward from the outer periphery of the main body 33. The surface of the main body 33 is smoother than the upper surface of the concrete foundation 31. The reinforcing plate 32 may also be configured to include only the main body 33. The reinforcing plate 32 of this embodiment is embedded in the concrete foundation 31 with the tip of the frame 34 protruding from the upper surface of the concrete foundation 31. A plurality of anchor bolts 36 protrude from the upper surface of the base 30, penetrating the main body 33 of the reinforcing plate 32.

[0048] The friction control plate 50 controls the frictional resistance between the base 30 and the substrate 40, and in this embodiment, can be formed from a member that increases the frictional resistance between the reinforcing plate 32 and the substrate 40, such as a plate made of resin or fiber-reinforced resin. In this embodiment, the friction control plate 50 is fitted into the frame portion 34 of the reinforcing plate 32 and fixed to the base 30. However, the installation form of the friction control plate 50 is not limited to this, and it may also be configured, for example, to be joined to the underside of the substrate 40 and move relative to the base 30 together with the substrate 40.

[0049] The stopper member 52 restricts movement of the substrate 40 toward the valley side of the ground slope and is installed on the valley side of the substrate 40 so as to protrude from the top surface of the base 30. The stopper member 52 may be any member that can abut against the substrate 40 to stop its movement when the substrate 40 moves on the base 30, and its shape may be selected appropriately, such as a plate or a rod, and its material may be selected appropriately, such as metal, resin, fiber-reinforced resin, or concrete. The stopper member 52 in this embodiment is formed by a part of the frame 34 of the reinforcing plate 32, specifically, one side of the rectangular frame 34 facing the valley side of the ground slope.

[0050] As shown in FIGS. 6 to 8 , the braking means 54 includes at least one rope 55 and two plate-shaped members 56 and 57. The braking means 54 of this embodiment uses two ropes 55. One end of each rope 55 is attached to the base 40 by a fixing member 59, and the other end is a free end. Each rope 55 is sandwiched between two plate-shaped members 56 and 57, which are firmly stacked and fixed to each other by a fastening member 58. One of the two plate-shaped members 56 and 57, the plate-shaped member 57, is flat, and the other plate-shaped member 56 has a groove 56a with an arc-shaped cross section through which each rope 55 is inserted when the other plate-shaped member 56 is stacked on the plate-shaped member 57. The plate-shaped members 56 and 57 of this embodiment are fixed to the base 30 via a friction control plate 50.

[0051] When the substrate 40 moves relative to the base 30, the ropes 55 of this brake means 54 are pulled by the substrate 40, and the ropes 55 move together with the substrate 40 while rubbing against the inner surfaces of the plate-like members 56, 57. This generates a frictional force between the plate-like members 56, 57 and the ropes 55, and the movement energy of the substrate 40 is absorbed.

[0052] In the protective fence 10 of this embodiment, the friction control plate 50 disposed in the support 20 between the base 30 and the substrate 40 can control the frictional resistance when the substrate 40 moves relative to the base 30. For example, the friction control plate 50 can increase the frictional resistance. This makes it possible to increase the amount of impact energy acting on the support 20 that can be absorbed.

[0053] Furthermore, when the substrate 40 moves, a frictional force is generated between the lobe 55 and the plate-like members 56 and 57 in the brake means 54 attached to the substrate 40. In this way, by generating a frictional force by the brake means 54, impact energy can be absorbed more effectively.

[0054] Furthermore, in this support structure 1, the movement distance of the substrate 40 can be restricted by the stopper member 52 fixed to the base 30, so even if the support main body 22 receives a large impact force due to a rockfall or the like, causing a large impact load to act on the substrate 40, the movement of the substrate 42 can be reliably stopped by both the long hole 42 formed in the substrate 40 and the stopper member 52.

[0055] Furthermore, in this embodiment, the substrate 40 is placed on the reinforcing plate 32 and is not in direct contact with the concrete foundation 31, so when the substrate 40 moves on the base 30, the frictional force generated between the substrate 40 and the concrete foundation 31 can be prevented from collapsing the surface of the concrete foundation 31.

[0056] (Third embodiment) Fig. 9 is a perspective view of a protective fence 10 equipped with a support structure 1 of the third embodiment, Fig. 10 is a cross-sectional view showing the main parts of the support structure 1 of the third embodiment, and Fig. 11 is a plan view of a support 20 of the third embodiment viewed from above. In the third embodiment shown in Figs. 9 to 12, parts corresponding to those in the first or second embodiment are given the same reference numerals. In the third embodiment described below, detailed description of the same configuration as in the first or second embodiment will be omitted.

[0057] In the support structure 1 of this embodiment, the support main body 22 is tiltably mounted on a base plate 40 via a hinge 26. In addition, a biasing means 48 is attached to the base plate 40 to bias the base plate 40 toward the mountain side of the ground slope. The protective fence 10 of this embodiment includes a plurality of support posts 20-1 to 20-4, a net 12, auxiliary ropes 14, and buffer means 16 attached to the auxiliary ropes 14, as well as upper support ropes 70, lower support ropes 72, holding ropes 74, and support ropes 76.

[0058] As shown in Fig. 9, upper support ropes 70 and lower support ropes 72 are laid horizontally on the upper and lower ends of the column row, respectively. The upper support rope 70 is laid in tension from one anchor 79 fixed to the ground slope, over the upper parts of each of the columns 20-1 to 20-4, to the other anchor 79. The lower support rope 72 is laid in tension from one anchor 79 fixed to the ground slope, over the lower parts of each of the columns 20-1 to 20-4, to the other anchor 79. The upper support ropes 70 and lower support ropes 72 are located on the upper and lower sides of the net 12, respectively.

[0059] Of the multiple pillars 20-1 to 20-4 that make up the pillar row, the inner pillars 20-2 and 20-3, excluding the pillars 20-1 and 20-4 at both ends, are strung with holding ropes 74 that extend from the top of the pillars to anchors 79 fixed to the ground on the mountainside. In this embodiment, two holding ropes 74 are provided for each pillar 20-2 and 20-3, and these holding ropes 74 enable the pillars 20-2 and 20-3 to be stably erected and the tilting movement of the pillars 20-2 and 20-3 to be adjusted.

[0060] The upper support ropes 70, the lower support ropes 72, the holding ropes 74, and the support ropes 76 are provided with buffer means 78. The buffer means 78 has the same configuration as the buffer means 16 shown in Fig. 2, and this buffer means 78 absorbs the sudden impact force when a rock falls, preventing the ropes from breaking.

[0061] 10 and 11, the hinge 26 provided between the substrate 40 and the support column main body 22 includes a fixed plate 27 fixed to the substrate 40 and standing upright from the substrate 40, and a shaft 28 attached to the fixed plate 27. The fixed plates 27 are arranged in pairs so as to sandwich the support column main body 22. The shaft 28 penetrates the support column main body 22 and the pair of fixed plates 27, and the support column main body 22 is installed on the substrate 40 so as to be tiltable around the shaft 28.

[0062] The biasing means 48 is attached to the substrate 40 and applies a biasing force to the substrate 40 that biases the substrate 40 toward the mountain side, at least when the substrate 40 moves toward the valley side on the base 30. The biasing means 48 is formed of an elastic member and attached to the substrate 40 so that it can expand and contract in the extension direction of the elongated hole 42 when installed. Examples of such biasing means 48 include a coil spring or a plurality of stacked disc springs. In this embodiment, the biasing means 48 is a coil spring having one end connected to the substrate 40 and the other end connected to the frame portion 34 of the reinforcing plate 32. In this embodiment, as an example, two coil springs serving as the biasing means 48 are provided on each of the valley side and the mountain side of the substrate 40. These coil springs may be set to their natural length, i.e., not expanded or contracted, when the support 20 is initially installed. Alternatively, they may be installed in an expanded or contracted state so as to bias the substrate 40 toward the mountain side. In this embodiment, the stopper member 52 is installed and fixed on the upper surface of the friction plate 52 fixed to the reinforcing plate 32. By providing the biasing means 48, it is possible to easily control the sliding load when the substrate 40 moves. Furthermore, the biasing means 48 allows for easy maintenance after the substrate 40 has moved.

[0063] Next, the operation of the guardrail fence 10 of the third embodiment will be described with reference to FIG. 12 . FIG. 12 is a side view of the guardrail fence 10, showing the net 12 of the guardrail fence 10 receiving collapsed soil 60. In FIG. 12 , the dashed lines indicate the initial positions of the support post body 22 and the base plate 40. When the collapsed soil 60 subjects the support post body 22 and the base plate 40 to an impact load of a predetermined value or greater, the support post body 22 moves together with the base plate 40 toward the valley side of the ground slope S and tilts relative to the base plate 40 due to the hinge structure provided at the lower end of the support post body 22. In this way, by tilting the support post body 22 in addition to the lateral movement of the base plate 40 and the support post body 22, a greater amount of impact energy can be absorbed. Furthermore, the hinge 26 can eliminate the moment acting on the base plate 40, i.e., the force acting in the direction that moves the base plate 40 away from the base 30, making it easier to control the load acting on the base plate 40 in the direction of movement.

[0064] Furthermore, when the substrate 40 moves relative to the base 30, the biasing means 48 attached to the substrate 40 expands and contracts the substrate 40, and the movement energy of the substrate 40, i.e., the impact energy received by the support body 22, is absorbed by the biasing means 48. In this way, the energy absorption efficiency can be further improved by absorbing the impact energy by the expansion and contraction of the biasing means 48.

[0065] 12, in this embodiment, the surface of the base 30 of the support 20 is inclined upward from the crest to the valley by a predetermined angle α with respect to the horizontal plane. By providing such an inclination to the base 30, it is possible to increase the amount of energy absorbed when the substrate 40 moves.

[0066] (Fourth embodiment) Fig. 13 is a cross-sectional view showing the main parts of a support structure 1 of the fourth embodiment, and Fig. 14 is a plan view of a support 20 of the fourth embodiment viewed from above. In the fourth embodiment shown in Figs. 13 and 14, parts corresponding to those in the first, second or third embodiment are given the same reference numerals. In the fourth embodiment described below, detailed description of the same configuration as in the first, second or third embodiment will be omitted.

[0067] In the support structure 1 of this embodiment, the base plate 40 on which the support body 22 is erected is clamped and fixed by a base 30 and a clamping plate 46 placed on the base plate 40. Specifically, the base 30 includes a concrete foundation 31 and a friction control plate 50. The base plate 40 is placed on the upper surface of the friction control plate 50, and the clamping plate 46 is placed on the upper surface of the base plate 40. In the illustrated example, the friction control plate 50 and the clamping plate 46 are set to be equal in size. A plurality of anchor bolts 38 are embedded and fixed in the base 30 so that their tips protrude from the upper surface. Each anchor bolt 38 penetrates the friction control plate 50 and the clamping plate 46, and a nut 39 is tightened from above the clamping plate 46, and the base plate 40 is clamped and fixed by tightening the nut 39.

[0068] The clamping plate 46 is preferably formed from a plate material with high strength and hardness, such as a steel plate. The friction control plate 50 is preferably formed from a plate material with lower hardness (softer) than the clamping plate 46, such as an aluminum alloy plate or a fiber-reinforced resin plate. In this embodiment, the friction control plate 50 is formed from a material softer than the substrate 40 so that the friction control plate 50 has a lower hardness than the substrate 40. With this configuration, when the substrate 40 moves, the surface of the friction control plate 50, which has a lower hardness, is deformed or damaged, thereby increasing the amount of energy absorption. Furthermore, during maintenance, only the damaged friction control plate 50 of the substrate 40 and the friction control plate 50 can be replaced.

[0069] Furthermore, by installing the friction control plate 50, it is possible to control the frictional resistance generated on the underside of the substrate 40. Specifically, because the concrete foundation 31 is poured at the installation site, it is difficult to control the unevenness of its surface, and if the substrate 40 is placed directly on the concrete foundation 31, the frictional resistance between the concrete foundation 31 and the substrate 40 will vary greatly depending on the unevenness. By installing the friction control plate 50 between the concrete foundation 31 and the substrate 40 as in this embodiment, it is possible to control the frictional resistance generated on the underside of the substrate 40 when the substrate 40 moves toward the valley side, and thereby it is possible to control the substrate 40 to move when a predetermined sliding load is reached.

[0070] An elongated hole 47 extending from the mountain side to the valley side of the ground slope is formed in the center of the clamping plate 46, and the pillar body 22 is erected on the base plate 40 with the hole 47 passing through it. In this embodiment, a hinge 26 is provided at the lower end of the pillar body 22, and the hinge 26 passes through the elongated hole 47 of the clamping plate 46. In the initial installation state, the base plate 40 and the pillar body 22 are positioned so that the pillar body 22 is located at the end of the elongated hole 47 on the mountain side of the ground slope. The fixing force of the nut 39 to the base 30 is set to such an extent that the base plate 40 can move on the base 30 along the elongated hole 47 of the clamping plate 46 when the base plate 40 receives a load of a predetermined value or more toward the valley side.

[0071] In this pillar structure 1, when a collision load acts on the pillar body 22 due to a rockfall or the like, the collision load acts on the base plate 40 via the pillar body 22 toward the valley side of the ground slope. When this collision load exceeds a predetermined value, the base plate 40 moves along the long holes 47 of the clamping plates 46 on the base 30 together with the pillar body 22 toward the valley side of the ground slope, thereby absorbing the impact energy of the rockfall or the like. Impact energy can also be absorbed by tilting the pillar body 22 via the hinges 26.

[0072] In this embodiment, the distance that the substrate 40 moves toward the valley side of the ground slope relative to the base 30 can be restricted by the longitudinal length of the elongated hole 47. Furthermore, although not shown, in this embodiment, a stopper member 52 protruding from the upper surface of the valley side of the friction control plate 50 or the lower surface of the valley side of the clamping plate 46 may be provided, so that the substrate 40 comes into contact with this stopper member 52, thereby restricting the movement of the substrate 40 toward the valley side.

[0073] (Fifth embodiment) Fig. 15 is a cross-sectional view showing a main part of the pillar structure 1 of the fifth embodiment, and Fig. 16 is a cross-sectional view taken along line AA in Fig. 15. In the fifth embodiment shown in Figs. 15 and 16, parts corresponding to those in the first, second or third embodiment are given the same reference numerals. In the fifth embodiment described below, detailed description of the same configuration as that of the first, second or third embodiment will be omitted.

[0074] In the support structure 1 of this embodiment, a pair of clamping plates 70A, 70B are erected and fixed on a reinforcing plate 32 that forms the surface of the base 30 so that the plate surfaces are perpendicular to the reinforcing plate 32, and a substrate 40 is clamped and fixed by these clamping plates 70A, 70B. In this embodiment, a pair of friction control plates 50A, 50B are attached to the inner surfaces of the pair of clamping plates 70A, 70B, and the substrate 40 is clamped and held by the clamping plates 70A, 70B via the friction control plates 50A, 50B. The friction control plates 50A, 50B control the friction resistance between the clamping plates 70A, 70B and the substrate 40, and the material of the friction control plates 50A, 50B can be the same as that of the friction control plate 50 of the second embodiment. Note that the friction control plates 50A, 50B are optional and not required components.

[0075] The reinforcing plate 32 is fixed to the surface of the concrete foundation 31 with anchor bolts 38 that protrude from and penetrate the reinforcing plate 32 and nuts 39 fastened to the anchor bolts 38. A pair of clamping plates 70A, 70B are arranged parallel to and facing each other at a predetermined distance and are formed into a rectangular shape extending elongatedly from the mountain side to the valley side. The base plate 40 is positioned so that its surface is perpendicular to the reinforcing plate 32 and is fixed by the pair of clamping plates 70A, 70B with a predetermined fixing force, i.e., a fixing force sufficient to allow the base plate 40 to move toward the valley side of the ground slope when subjected to a load greater than a predetermined value toward the valley side. The support body 22 is tiltably installed on the base plate 40 via a hinge 26. A pair of fixing plates 27 that constitute the hinge 26 are attached so as to sandwich both surfaces of the base plate 40.

[0076] The base plate 40 is fixed to the base 30 with a predetermined fastening force by a plurality of bolts 76 that penetrate the pair of clamping plates 70A, 70B, the pair of friction control plates 50A, 50B, and the base plate 40, and a plurality of nuts 78 that are threaded onto these bolts 76. Each bolt 76 penetrates an elongated hole 72 formed in the clamping plates 70A, 70B and an elongated hole 51 formed in the friction control plates 50A, 50B. The elongated holes 72 in the clamping plates 70A, 70B and the elongated holes 51 in the friction control plates 50A, 50B extend elongatedly from the crest side to the root side, and are formed to be approximately the same size and shape so that the holes overlap in the thickness direction. The inner diameter of the hole in the base plate 40 through which the bolt 76 penetrates is set to be approximately the same as the outer diameter of the bolt 76. In this embodiment, when a load greater than a predetermined value acts on the substrate 40, the substrate 40 and the bolt 76 move from the crest side to the valley side along the long holes 72, 51 relative to the base 30 and the clamping plates 70A, 70B firmly fixed thereto.

[0077] The elongated holes 72, 51 that restrict the movement of the bolts 76 may be configured to be formed on the substrate 40 side (i.e., the side that moves relative to the base 30) rather than on the clamping plates 70A, 70B side (i.e., the side that is firmly fixed to the base 30 and does not move). Also, the friction control plates 50A, 50B may be configured to be attached to both surfaces of the base 40, rather than to the clamping plates 70A, 70B.

[0078] The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the invention.

[0079] For example, in the embodiment shown in Fig. 7, a destructible member that receives a load from substrate 40 and breaks when substrate 40 moves toward the valley side may be provided in region 68 within the range of movement of substrate 40 on the valley side of substrate 40. The destructible member is made of a highly brittle material, such as a resin material, a rubber material, or aerated concrete containing a large number of air bubbles, such as air mortar. Note that such a destructible member can also be applied to the other embodiments described above.

[0080] FIG. 17 shows a modified example of the support structure 1 equipped with a destructible member. In this modified example, the shape of the substrate 40 in the second embodiment is changed, and plate-shaped destructible members 66 are provided on both sides of the substrate 40. In FIG. 17, the non-destructible members 66 are indicated by dots for ease of understanding. The configuration of the other members is the same as in the second embodiment.

[0081] The substrate 40 of this modified example is formed in a trapezoid shape with the width dimension of the valley side set smaller than the width dimension of the peak side. In the illustrated example, the substrate 40 is formed in an isosceles trapezoid, which is an axisymmetric trapezoid in a plan view. The destructible member 66 is placed on the reinforcing plate 32 via the friction control plate 50, and is fixedly installed in contact with both sides of the substrate 40 (i.e., the side edges forming a pair of legs of the trapezoid), and is arranged so as to fill the gap between both sides of the substrate 40 and the frame portion 34 of the reinforcing plate 32.

[0082] In the support structure 1 shown in Fig. 17, when the substrate 40 receives a load of a predetermined value or more toward the valley side, the substrate 40 moves toward the valley side while destroying the destructible members 66 arranged on both sides. By destroying the destructible members 66 in this way, it is possible to absorb the impact energy and mitigate the impact on the support main body 22. Note that such destructible members 66 can be applied to other embodiments by changing the shape of the substrate 40 to a trapezoidal shape and providing a frame portion 34 that fixes the destructible members 66.

[0083] As in the above-described embodiments and modifications, the support structure 1 according to the present invention preferably includes a fixing mechanism that fixes the substrate 40 to the base 30 with a predetermined fixing force (i.e., a fixing force sufficient to allow the substrate 40 to move on the base 30 toward the valley side when a load equal to or greater than a predetermined value acts on the valley side of the ground slope), and a guide mechanism that guides the movement of the substrate 40 so that the substrate 40 moves toward the valley side within a predetermined distance when a load equal to or greater than the predetermined value acts on the substrate 40 and the substrate 40 becomes unfixed to the base 30. The guide mechanism preferably includes an elongated hole formed in either the substrate 40 or the fixing mechanism, and a penetrating member attached to the other of the substrate 40 or the fixing mechanism, which passes through the elongated hole and moves within the elongated hole in the direction of extension of the hole.

[0084] In the first, second, and third embodiments, the fixing mechanism includes an anchor bolt 36 attached to the base 30 and a nut 37 fastened to the anchor bolt 36, sandwiching the substrate 40 between the base 30 and the anchor bolt 36. The guide mechanism includes an elongated hole 42 formed in the substrate 40 and the anchor bolt 36 passing through the elongated hole 42. In the second and third embodiments, a stopper member 52 further constitutes a guide mechanism that restricts movement of the substrate 40 toward the valley side. In the fourth embodiment, the fixing mechanism includes a clamping plate 46 that clamps the substrate 40 together with the base 30, and the anchor bolt 36 and nut 39 that apply a clamping force to the clamping plate 46. The guide mechanism includes an elongated hole 47 formed in the clamping plate 46 and a support main body 22 that passes through the elongated hole 47. In addition, in the fifth embodiment, the fixing mechanism is configured to include a pair of clamping plates 70A, 70B fixed to the base 30, and bolts 76 and nuts 78 that fix the substrate 40 to the clamping plates 70A, 70B with a predetermined fixing force, and the guide mechanism is configured to include elongated holes 72 formed in the clamping plates 70A, 70B and bolts 76 that pass through the elongated holes 72.

[0085] Furthermore, in the support structure 1 according to the present invention, the reinforcing plate 32, friction control plate 50, stopper member 52, braking means 54, hinge 28, biasing means 48 and destructible member 66 are not essential components, and the support structure 1 according to the present invention can use any one or a combination of these. Also, the support body 22 of the first embodiment shown in Fig. 1 may be configured to have a retaining rope 74 and a buffer member 78 shown in Fig. 9 attached to it, thereby suppressing the moment acting on the support body 22 and absorbing impact loads. [Explanation of symbols]

[0086] 1 pillar structure 10 Protective fence 12 Net 20 pillars 22 Pillar body 24 Support member 26 Hinge 28 Shaft 30 Foundation 31 Concrete Foundation 32 Reinforcement plate 36,38 Anchor bolts 37,39 Nut 40 boards 42 long hole 48 Actuation means 50 Friction control plate 52 Stopper member 54 Braking means 55 Rope 56,57 Plate-shaped members 66 Destructible Members 70A,70B,76 Holding plate

Claims

1. A support structure for a protective fence that is installed on the ground at predetermined intervals to stretch a protective net, the support structure comprising a base constructed on the ground and a support body installed on the base, a substrate that is placed directly or indirectly on the base and has the support body erected on an upper surface; a guide mechanism that guides the movement of the base plate and the support pillar body on the base from the mountain side to the valley side of the ground slope, The guide mechanism includes: a clamping member fixed to the base and configured to clamp the substrate with a predetermined clamping force; a slot formed in the clamping member and extending from the crest side to the valley side; a penetrating member attached to the substrate and passing through the slot, The penetrating member moves along the extension direction of the long hole, thereby allowing the substrate and the support column body to move toward the valley side, The clamping force of the clamping member is A guardrail support structure characterized in that when the guardrail catches a falling rock and a load of a predetermined value or more acts on the base plate toward the valley, the clamping force is such that the base plate and the support body can be guided by the guide mechanism and move toward the valley.

2. the clamping member is a clamping plate that is disposed parallel to the base and clamps the substrate in cooperation with the base, the penetrating member is the support column body erected on the substrate, or a hinge whose lower part is fixed to the substrate and whose upper part supports the support column body so that the support column body can tilt, The support structure described in claim 1, characterized in that the substrate is clamped between the base and the clamping plate by screwing a nut onto an anchor bolt that protrudes from the base and penetrates the clamping plate, with the penetrating member penetrating the mountain-side end of the long hole.

3. the clamping members are a pair of clamping plates that are disposed perpendicular to the base and clamp the substrate that is disposed perpendicular to the base, the penetrating member is a bolt that is attached to the base plate in a state where it penetrates the base plate, and both ends of the bolt penetrate the elongated holes of the pair of clamping plates, The support structure according to claim 1, characterized in that the base plate is clamped between the pair of clamping plates by screwing a nut onto the bolt with the bolt passing through the mountain-side end of the long hole of the pair of clamping plates.

4. The support structure according to claim 2, further comprising a friction control plate disposed between the substrate and the base, for controlling frictional resistance between the substrate and the base.

5. The support structure according to claim 3, further comprising a friction control plate disposed between the substrate and the pair of clamping plates to control frictional resistance between the substrate and the pair of clamping plates.

6. 6. The support structure according to claim 3, wherein the support body is tiltably mounted on the base plate via a hinge.

7. The support structure according to any one of claims 1 to 6, characterized in that the base comprises a concrete foundation provided on a ground slope and a metal reinforcing plate installed on the concrete foundation and on which the substrate is placed.

8. A support structure as described in any one of claims 7 to 11, characterized in that one end is attached to the substrate and the other end is attached to a frame portion protruding upward from the outer peripheral edge of the reinforcing plate, and the support structure is provided with a biasing means that expands or contracts when the substrate moves toward the valley side, thereby biasing the substrate toward the mountain side.

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