JP7034464B2 - Rockfall guard rail - Google Patents

Description

The present invention relates to a rockfall guard fence and a rockfall guard fence that can be installed not only on a mountain slope but also on a road or a railroad.

Conventionally, in order to reduce the damage caused by rockfall, rockfall protection fences have been widely installed on mountain slopes (including slopes). There are various types of such rockfall guard fences. For example, a plurality of columns are erected on a slope and the net body is supported by these columns so that the columns are arranged in the direction of arrangement (usually substantially horizontal). There is a net body stretched in the direction). This type of rockfall guard fence takes advantage of the deformability of the net body and captures the rockfall with the deformation of the net body, thereby reducing the damage. In other words, when the rockfall comes into contact with the net body, the impact is dispersed by deforming the net body itself, and the maximum impact value is reduced by the time required for the deformation of the net body, which can absorb the kinetic energy of the rockfall. can.

As a rockfall protection fence in which such a net body is stretched between columns, for example, there is one described in Patent Document 1 below. In the rockfall protection fence described in Patent Document 1, a ring-type net is used as a net body, and an auxiliary rope is provided between the upper side position and the lower side position of the net body among the columns to which the net body is stretched. It is laid across in the left-right direction (horizontal direction of the slope) when viewed from the front of the slope and fixed to the support, and the auxiliary rope is a buffer that allows the extension of the length between the fixed parts at both ends of the auxiliary rope when a load due to rockfall is applied. Means were provided. Therefore, for example, when the rockfall comes into contact with the net body and a load is applied prior to the absorption of the rockfall kinetic energy due to the deformation of the ring type net, the cushioning means cushions the impact as the total length of the auxiliary rope extends, so that the rockfall Kinetic energy is efficiently absorbed. In addition, the auxiliary rope in the state where no load is applied is only to stretch the net body between the columns. For example, when the net body is stretched to three or more columns, the auxiliary rope is attached to the columns at both ends ( Or it is fixed only on the slope).

Japanese Unexamined Patent Publication No. 2014-1584

By the way, when a rockfall protection fence using this kind of net body is installed, for example, on a road or a railroad, a net that captures the rockfall in consideration of the influence on vehicles passing through the road or railroad. It is necessary not to make the dimension of the body protruding below the slope or in the direction of protruding from the slope too large. In other words, this is to reduce the amount of deformation from the original upholstery position of the net body that captured the rockfall (hereinafter, also referred to as the set upholstery position). However, since the auxiliary rope of the rockfall protection fence described in Patent Document 1 is not connected to each support, the support is caused by the deformation of the net body and the extension of the auxiliary rope, specifically, the slope of the upper part of the support. It is difficult to suppress the downward tilt. When the column is tilted downward on the slope in this way, the amount of deformation of the net body from the set upholstery position increases accordingly. Such a situation where the amount of deformation of the net body when a rock falls occurs should be avoided as much as possible when the installation area of the inauguration guard fence is close to a traffic route such as a road or a residential area. Must be.

The present invention has been made in view of the above problems, and an object of the present invention is to suppress the amount of deformation of the net body that has captured the falling rock from the set upholstery position by suppressing the tilting of the support column downward on the slope. It is to provide a rockfall guard rail that is possible.

The rockfall guard rail to achieve the above purpose is
A plurality of columns erected on the slope at predetermined intervals in the left-right direction of the front view of the slope, and a net body stretched between the columns by being supported by the plurality of columns are provided. In the rock fall protection fence, each of the columns is characterized in that a tension material for restricting the movement of the adjacent columns in a direction away from each other is erected between the columns and the adjacent columns.

According to this configuration, when the net body catches the rockfall, a force in the direction of tilting the column is applied by the energy of the rockfall collision transmitted from the net body. However, since each strut is sequentially connected to the adjacent strut by a tension material, the strut away from the rockfall collision point and the strut to which the force in the tilting direction is applied by the tension material are separated from each other. You can regulate trying to move. As a result, it is possible to suppress the support from tilting downward on the slope when a rock fall occurs, and it is possible to suppress the amount of deformation of the net body that has captured the rock fall from the set tension position.

Further , the tension material is erected between the upper portions of the adjacent columns, has a predetermined rigidity, and the tension rod member that regulates the upper portions of the adjacent columns from being close to each other is substantially parallel to the tension material. It is characterized in that it is arranged between the upper parts of adjacent columns.

According to this configuration, when the net body catches rockfall and is pulled by the net body so that the upper parts of the adjacent columns on both sides supporting the net body try to approach each other, the support of the column The proximity of the upper part is regulated by the tension rod member, which avoids unnecessary slackening of the net body and can reduce the amount of deformation of the net body that has captured the falling rock from the set tensioning position.

Further , the tension rod member is a tubular body, and the tension material is inserted into the inside of the tubular tension rod member.

According to this configuration, since the tension member and the tension rod member can be arranged at the same position, one of the adjacent columns tilts and tries to separate from each other, or the upper portions of both tend to approach each other. This makes it possible to efficiently regulate the amount of deformation from the set tension position of the net body that captures rockfall in any situation.

Further , the tension material is connected to the support column via a connecting member that is fixed to the support column and deforms at the time of a rock fall collision to absorb energy, and the end portion of the tension rod member is connected to the connecting member. It is characterized by that.

According to this configuration, the breakage of the connecting structure between the tension member and the column due to the energy of the rockfall collision transmitted from the net body that captured the falling rock can be suppressed by stretching the tension material and deforming the connecting member. As a result, the function of the tension rod member is maintained, and the amount of deformation of the net body that has captured the falling rock from the set tension position can be kept small. Further, the tension material and the tension rod member can be simply connected to the support column in a state where the tension material is inserted into the tubular tension rod member, and the cost and weight can be reduced accordingly.

Further , when the tension material is erected between the adjacent columns and the tension rod member is arranged between the adjacent columns, the connecting member penetrates the column in the left-right direction of the slope and penetrates the support member. It is characterized in that an end portion of a tension material erected between the adjacent columns and an end portion of a tension rod member arranged between the adjacent columns are connected to the portion.

According to this configuration, the tilting of the columns pulled by the net body that captured the rockfall can be further suppressed by the tension material and the tension rod member between the adjacent columns, so that the tilting of the columns can be further suppressed. At the same time, it is possible to suppress the breakage of the connecting structure between the support column and the tension rod member, and thereby it is possible to further reduce the amount of deformation of the net body that has captured the falling rock from the set tensioning position.

Further , the support column is configured by inserting H-shaped steel inside the steel pipe member, and the web of the H-shaped steel is arranged toward the maximum inclination line direction of the slope, and the connecting member is the steel pipe member and the H. It is characterized in that it is arranged through the web of the shaped steel.

According to this configuration, the strut has sufficient strength (rigidity) against the load transmitted from the net body that captures the fallen rock at the time of a rockfall collision, so that the tilting of the strut itself is reduced or suppressed, thereby preventing rockfall. The amount of deformation of the captured net body from the set tension position can be reduced. In addition, the weight of the columns can be reduced, and the structure through which the connecting members penetrate the columns is simplified, resulting in easier construction.

As described above, according to the present invention, when the net body captures rockfall, a force in the direction of tilting the column is applied by the energy of the rockfall collision transmitted from the net body, but each column has its own force. Since the columns are connected to the adjacent columns in sequence with a tension material, the movement of the columns away from the rockfall collision point and the tension material regulates the movement of the columns to which the force in the tilting direction is applied. As a result, it is possible to suppress the support from tilting downward on the slope when a rock fall occurs, and it is possible to suppress the amount of deformation of the net body that has captured the rock fall from the set tension position.

It is a partial cross-sectional whole front view which saw the embodiment of the rockfall protection fence of this invention from the slope valley side. It is a partial cross-sectional side view of the rockfall protection fence of FIG. It is a front view of the net body from the rhombic wire mesh used for the rockfall protection fence of FIG. It is a front view which shows an example of the brake device used for the rockfall protection fence of FIG. It is a perspective view which shows the other example of the brake device used for the rockfall guard fence of FIG. It is explanatory drawing of the operation of the rockfall guard fence of FIG. It is explanatory drawing which shows the state which the rockfall was captured by the rockfall guard fence of FIG. It is a perspective view of the connecting structure of the tension rod member and the tension material of the rockfall protection fence of FIG. 8 is a three-view view of the connected structure, where FIG. 8A is a partial sectional plan view and FIG. 8B is a partial sectional front view. It is a front view of the ring type net which can be used as a net body of FIG.

Hereinafter, embodiments of the rockfall guard fence of the present invention will be described in detail with reference to the drawings. FIG. 1 is a partial front view of the rockfall protection fence of this embodiment as viewed from the slope valley side, and FIG. 2 is a partial cross-sectional side view thereof. The rockfall guard fence according to this embodiment is the same as the existing rockfall guard fence, for the purpose of preventing damage due to rockfall falling on the slope (including the slope) S, etc. ) Is extended. In this embodiment, a base-shaped concrete structure 12 having a constant height and continuous in the lateral direction of the slope is formed as a foundation of a rockfall protection fence. The concrete structure 12 is constructed by, for example, placing concrete around a skeleton (not shown).

From the upper surface of the concrete structure 12, a plurality of columns (4 in the figure) are erected at predetermined intervals in the lateral direction of the slope. In the rockfall protection fence of this embodiment, the net body 14 is stretched between the columns 10 while the net body 14 is supported by these columns 10, and the net body 14 catches the rockfall to prevent damage. It is a thing. Rockfalls include not only those that roll down along the slope S, but also those that fall in a state of floating away from the slope S. Since the floating rockfall is also captured by the net body 14, the support column 10 that supports the net body 14 also needs to have a certain height. In addition, it is not possible to predict where the rockfall will occur in the lateral direction of the slope. Therefore, the height of the columns 10 is, for example, 2 m to 5 m, the distance between the columns 10 is, for example, 3 m to 5 m, and in some cases, about 10 m, which are appropriately selected according to the scale and situation of the slope S. As will be described later, the support column 10 is configured by inserting the H-shaped steel 38 into the steel circular pipe material 36 so that the web 38a of the H-shaped steel 38 is in the direction of the maximum slope line of the slope. The lower end is buried in.

For the net body 14 of this embodiment, for example, as shown in FIG. 3, a rhombic wire mesh 22 made of a metal wire having a rhombic mesh is used. As described in Japanese Patent Application Laid-Open No. 2016-37773, for example, the diamond-shaped wire mesh 22 is formed by bending a metal wire rod 24 into a triangular wavy wire, and has peaks and valleys of a plurality of triangular wavy wires arranged in parallel. It consists of knitting with each other and engaging those triangular wavy wires. Mild steel, hard steel, spring steel, stainless steel, or the like can be used for the metal wire 24 constituting the triangular wavy wire. The metal wire 24 may be coated if necessary, whereby wear and corrosion of the contact portion of the triangular wavy wire can be prevented. Examples of the coating treatment include a zinc plating treatment and a polyester coating treatment.

In this embodiment, since it is important to reduce the maximum amount of deformation of the net body 14 itself in order to reduce the amount of deformation of the net body 14 from the set stretching position, the net body 14 made of the diamond-shaped wire mesh 22 is configured. It is desirable that the metal wire 24 to be used also has a small amount of deformation and a relatively high mechanical strength. Therefore, a specifically preferable metal wire 24 is a wire made of hard steel (single wire), particularly a wire made from the hard steel wire specified in JIS G 3506, for example, a hard steel wire (JIS G 3521). , Galvanized steel wire (JIS G 3548) and the like. It is advantageous that the tensile strength of the wire is, for example, 800 to 2500 N / mm ² , preferably 1000 to 2000 N / mm ² , and particularly 1500 to 2000 N / mm ² . By using such a hard steel wire, it is possible to obtain a net body 14 having high rigidity and low weight. As the metal wire 24, it is also preferable to use a wire made of hard steel having excellent elastic deformability. The thickness (wire diameter) of this type of single wire metal wire 24 is, for example, 2 to 10 mm, preferably 2.6 to 4 mm.

The wire used for the net body of the conventional rockfall protection fence is a mild steel wire, that is, an iron wire, and is relatively easily plastically deformed. Therefore, the amount of energy absorbed by the net body of the mild steel wire is small, and the auxiliary rope (lateral reinforcing rope 26 in this embodiment) arranged on the slope valley side of the net body is mainly used for falling rocks as in the above-mentioned conventional technique. Absorbs the kinetic energy of. As a matter of course, the maximum amount of deformation of the net body of the conventional mild steel wire rod is large. On the other hand, since the net body 14 made of the hard steel wire rod as in this embodiment has high rigidity while being lightweight, the amount of energy absorbed due to the deformation of the net body 14 is large. Therefore, the kinetic energy of falling rocks can be largely absorbed by the deformation of the net body 14 made of the hard steel wire rod. As a result, the net body 14 made of hard steel wire has a small maximum deformation amount at the time of trapping rockfall, and the deformation amount from the set tensioning position is also small.

Further, the metal wire 24 may be a stranded wire configured by twisting a plurality of strands, for example, as described in Japanese Patent Application Laid-Open No. 2014-66054. What is preferable as the stranded wire is a stranded wire (diameter 6 to 25 mm) produced by twisting a plurality of strands (for example, 2 to 5 mm in diameter). As the strands, those having a tensile strength of 400 to 2000 N / mm ² , preferably 800 to 2000 N / mm ² are used. As such a wire, for example, the above-mentioned hard steel wire can be used. By using the stranded wire, when the metal wire 24 is bent into a triangular wavy shape, it can be bent without damaging the wire itself. It is preferable that the strands are anticorrosion treated. The anticorrosion treatment can be performed by, for example, galvanizing, zinc-aluminum alloy plating, or coating with a resin (polypropylene, polyethylene, polyvinyl chloride) or the like.

The size of the rhombic mesh of the rhombic wire mesh 22 constituting the net body 14 is, for example, as described in Japanese Patent Application Laid-Open No. 2013-19198, the radius of the inscribed circle of the rhombus is about 4.5 to 8.5 cm. It is configured to be in the range of. By constructing the mesh to such a size, it is possible to construct a sufficiently large mesh while preventing rockfall from passing through the mesh of the net body 14, so that the deformability of the net body 14 is appropriate. The absorption of kinetic energy of falling rocks by the net body 14 is further promoted. The size of this mesh can be obtained, for example, by setting the shorter diagonal of the constructed rhombus to be in the range of 5 to 20 cm, the longer diagonal to be 10 to 30 cm, and the smaller internal angle to be in the range of 50 ° to 70 °. .. In this way, by making the mesh a rhombus instead of a square (or a regular polygon), the radius of the inscribed circle can be made small even if the length of one side of the mesh is the same, and therefore rockfall can be prevented. It is possible to capture without omission. Further, in this embodiment, the net body 14 is installed so that the extending direction of the longer diagonal line of the formed rhombus is the left-right direction (horizontal direction) of the slope. As a result, if the net body 14 has a diamond-shaped mesh of the same shape, the tensile strength in the lateral direction can be the strongest, so that it is possible to more effectively catch the falling rocks falling on the slope valley side. can.

The shape of the mesh of the net body 14 is not limited to the rhombus, but may be polygonal as appropriate. Further, as described later, for the net body 14, for example, the ring type net described in the above-mentioned Patent Document 1 can be used. Further, as will be described later, the lower end portion of the net body 14 is a concrete structure 12, that is, a slope so that, for example, rockfall captured by the net body 14 does not fall again from the gap between the net body 14 and the concrete structure 12. It is desirable to make it as close as possible to the concrete and to make the gap between the two as small as possible.

In this embodiment, for example, similarly to the above-mentioned Patent Document 1, a lateral reinforcing rope 26 is laid and fixed between the columns 10 at least at both ends in the lateral direction of the slope among the plurality of columns 10, and the lateral direction thereof. The reinforcing rope 26 is inserted or connected to the net body 14, thereby reinforcing the net body 14. The lateral reinforcing rope 26 indirectly supports the rockfall by supporting the net body 14 that has captured the rockfall, and also absorbs the kinetic energy of the rockfall. The right end of FIG. 1 of the lateral reinforcing rope 26 is firmly fixed to the support column 10 at the right end of the drawing via the locking tool 28, and the left end of FIG. 1 is a braking device described later. It is fixed to the support column 10 at the left end of the figure via the 30. For example, a high-strength wire rope or the like is applied to the lateral reinforcing rope 26. The wire diameter of the lateral reinforcing rope 26 is, for example, about 12 to 30 mm.

In this embodiment, a plurality of lateral reinforcing ropes 26 (six in the present embodiment) are stretched at intervals at the top and bottom. In this embodiment, the uppermost lateral reinforcing rope 26-1 is arranged on the upper side portion of the net body 14, and the lowermost lateral reinforcing rope 26-6 is arranged on the lower side portion. These lateral reinforcing ropes 26 are inserted so as to sew the mesh of the diamond-shaped wire mesh constituting the net body 14, and are firmly fastened by the fastening member 4 together with the spacing member 2 described later. The lateral reinforcing rope 26 may be arranged on the slope valley side of the net body 14. Further, the number of lateral reinforcing ropes 26 arranged is not limited to the above, but at least the lateral reinforcing ropes 26 are arranged on the lower side portion, preferably the upper side portion and the lower side portion of the net surface of the net body 14. It is desirable to set it. Further, the lateral reinforcing rope 26 does not necessarily have to be bridged in the horizontal direction.

The actual lateral reinforcing rope 26 is slightly loosened downward due to its own weight and the weight of the net body 14. The kinetic energy absorption effect of falling rocks by the net body 14 is exhibited by the deformation of the net body 14. On the other hand, in the lateral reinforcing rope 26, when rockfall is caught by the net body 14, the net body 14 bulges toward the slope valley side, the rope is not slackened, and tension is generated in the lateral reinforcing rope 26. It is possible to support the net body 14 that has captured the falling rocks. At this time, if a braking force is applied to the elongation while allowing the elongation of the lateral reinforcing rope 26, the kinetic energy of the falling rock can be absorbed by the elongation of the lateral reinforcing rope 26 accompanied by the braking force. Therefore, a braking device 30 is provided at the left end portion of the lateral reinforcing rope 26 in the drawing to allow an extension of the length between both fixing portions of the rope with a predetermined braking force.

FIG. 4 shows an example of a braking device 30 that applies a braking force while allowing the rope to stretch. This figure is a front view of the brake device 30 of FIG. 1 as viewed from the mountain side of the slope. The brake device 30 is configured by winding a metal strip 52 having a width in the vertical direction of the paper around a solid cylindrical member 54, and is short from one end of the metal strip 52 in the longitudinal direction, in this case, the cylindrical member 54. The end of the lateral reinforcing rope 26 is connected to the end of the side. Further, a stopper 58 is provided at the other end of the metal band 52, and two cushioning protrusions 60 protruding in pairs on both surfaces of the metal band 52 are provided in front of the stopper 58. It is provided in. Further, in the brake device 30, a holding member 56 for holding the metal band 52 relatively tightly is attached to the outside of the metal band 52 wound around the columnar member 54, and the holding member 56 is engaged. It is fixed to the side surface of the slope of the support column 10 on the left end side in the drawing of FIG. 1 via the stopper 28.

In this brake device 30, tension is applied to the lateral reinforcing rope 26, and when the rope is pulled in the direction of the arrow in the figure, the metal band 52 is also pulled in the same direction. At this time, the metal band 52 must pass through a narrow passage formed by the cylindrical member 54 and the holding member 56, and at that time, the portion wound around the cylindrical member 54 moves. In the portion of the metal band 52 wound around the cylindrical member 54, plastic deformation continuously occurs as the wound portion moves. Since the continuous plastic deformation accompanying the movement of the winding portion of the metal band 52 around the cylindrical member 54 is deformation resistance, the length between both fixing portions of the lateral reinforcing rope 26 is extended against this deformation resistance. At this time, a braking action, that is, a braking force is generated, and the kinetic energy of the falling rock acting on the lateral reinforcing rope 26 is largely absorbed. The amount of extension of the lateral reinforcing rope 26 is regulated by the position of the stopper 58.

FIG. 5 is a perspective view showing another example of the brake device 30. The brake device 30 is composed of a loop pipe 32 and a tightening member, and an intermediate portion of the lateral reinforcing rope 26 is inserted through the loop pipe 32. Both ends of the loop tube 32 are overlapped in parallel, and the superposed portion is compacted by a tightening member, for example, a compression sleeve 34, and the superposed portion of the loop tube 32 is mutual at the portion compacted by the compression sleeve 34. The loop tube 32 and the compression sleeve 34 are also in frictional contact with each other. The loop tube 32 is preferably made of steel, but can also be made of another metal material, plastic material, or rubber material.

In this brake device 30, when a large tension is generated in the lateral reinforcing rope 26, a force for reducing the diameter of the loop pipe 32 acts, and both ends of the loop pipe 32 exert a force in opposite directions along the rope. receive. When the tension applied to the rope exceeds the frictional force between the loop tubes 32 and between the loop tubes 32 and the compression sleeve 34 at the compaction point by the compression sleeve 34, slippage occurs between the loop tubes 32 against the frictional resistance. This slip causes the kinetic energy of the falling rock to be absorbed while being stretched between both fixed portions of the lateral reinforcing rope 26. At that time, the kinetic energy is also absorbed by the deformation of the loop tube 32. By selecting the diameter, wall thickness, and material of the loop tube 32, the energy absorption capacity can be variously changed, and various demands can be met. In the figure, the case where the loop tube 32 has one winding is shown, but the number of windings may be double winding or more.

In FIG. 1, one brake device 30 is provided for one lateral reinforcing rope 26, but a plurality of brake devices 30 may be provided for one lateral reinforcing rope 26. When a plurality of brake devices 30 are provided for one lateral reinforcing rope 26, the magnitudes of the braking forces of the brake devices 30 may be set to different sizes from each other. As described above, the braking force of the braking device 30 depends on the tension of the lateral reinforcing rope 26. With such braking force distribution, for example, when two braking devices 30 are provided on one lateral reinforcing rope 26, the tension of the lateral reinforcing rope 26 that supports the net body 14 that has captured the falling rocks increases. Accordingly, one of the brake devices 30 operates first to exert the braking force, and then the other brake device 30 operates to exert the braking force. By doing so, it becomes possible to continuously or intermittently exert a braking force, that is, to continuously absorb kinetic energy while the lateral reinforcing rope 26 supporting the falling rock continues to stretch.

In this embodiment, in the region between the columns 10 and the columns 10, the interval holding member 2 that is long (extended) in the vertical direction (longitudinal direction) is arranged so as to abut or approach the net body 14. .. The space holding member 2 is made of, for example, a steel plate or bar, and has at least higher rigidity than the net body 14. Further, it is desirable that the space holding member 2 has a lower rigidity than the support column 10. For example, the rigidity of the space holding member 2 is 1/10 to 1/3, preferably 1/6 to 1/4 of the rigidity of the support column 10. And. Here, the rigidity is, as is well known, represented by, for example, the product value of Young's modulus E and moment of inertia of area I. In the case of this embodiment, the rigidity to be evaluated is the rigidity in the direction deformed by the falling rock, that is, the rigidity in the direction perpendicular to the surface of the net body 14. The rigidity of the space holding member 2 in the direction perpendicular to the surface of the net body 14 is 1/10 to 1/3, preferably 1/6 to 1/4 of the rigidity of the support column 10.

In this embodiment, a total of three spacing members 2 are arranged between the columns 10 with one in the middle of the column 10 and the column 10, one on each side in the lateral direction thereof, with a predetermined interval. There is. The number of arrangements of the interval holding member 2 is not limited to this. These spacing members 2 are arranged, for example, on the mountain side of the slope with respect to the net body 14. Further, in this embodiment, the length of the space holding member 2 is the same as the vertical (vertical) length of the net body 14, and therefore, the space holding member 2 is vertically from the upper side to the lower side of the net body 14. It touches the entire direction. That is, the upper end portion of the spacing member 2 abuts on the uppermost lateral reinforcing rope 26-1 located on the upper side of the net body 14, and the lower end portion of the spacing member 2 is the lowermost portion located on the lower side of the net body 14. Abuts on the lateral reinforcing rope 26-6 of. Then, in this embodiment, they are fastened together with the wire rod of the net body 14 by the fastening member 4 at the position where the spacing member 2 and the lateral reinforcing rope 26 intersect. Therefore, as will be described later, the spacing member 2 maintains the vertical spacing of the lateral reinforcing rope 26 as well as the function of transmitting the kinetic energy of the falling rock that collided with the net body 14 in the vertical direction of the net body 14. It also has a function.

Further, in this embodiment, as clearly shown in FIG. 1, a tension rod member 16 having a predetermined rigidity is arranged between the upper ends of adjacent columns 10, and the tension rod member 16 is a so-called tension rod. To regulate the proximity of both columns 10 to each other. In this embodiment, the end portion of the tension rod member 16 and the upper end portion of the support column 10 are connected by a connecting structure described later. It is desirable that the rigidity of the tension rod member 16 is at least larger than the rigidity of the net body 14 and smaller than the rigidity of the support column 10. The tension rod member 16 restricts the columns 10 pulled downward by the net body 14 from being close to each other when the falling rock is captured by the net body 14, as will be described later. As a result, unnecessary bending of the net body 14 can be suppressed, and as a result, the amount of deformation of the net body 14 that has captured the falling rock from the set tensioning position can be reduced. The tension rod member 16 is made of a rigid tubular body such as a steel circular pipe, and a tension material 6 is inserted into the strut member 16 as described in detail later, and both ends thereof are adjacent to each other. By connecting to each of the above, the tension member 6 is erected between the adjacent columns 10.

FIG. 6 is a cross-sectional view (side view) schematically showing the operation of the existing rockfall guard fence and the rockfall guard fence of this embodiment. In FIG. 6, only the uppermost and lowermost lateral reinforcing ropes 26 are shown, and the other lateral reinforcing ropes are not shown. FIG. 6A is a conventional existing rockfall protection fence in which a net body 14 such as a rhombic wire mesh is stretched between columns 10 without an interval holding member 2. The net body 14 is deformed by the collision of the falling rock R. As shown in FIG. 6A, in the rockfall guard fence without the space holding member 2, only the contact portion of the rockfall R is locally deformed in the direction in which the net body 14 protrudes below the slope or from the slope S. As shown in FIG. 6A, when the net body 14 is locally deformed only at the contact portion of the rockfall R to absorb the kinetic energy of the rockfall R, the maximum amount of deformation of the net body 14 is large. Further, the local deformation of the net body 14 due to such rockfall capture is smaller as it is closer to the support column 10, and conversely, it is the largest in the middle of the support column 10 and the support column 10 as it is farther from the support column 10. When the maximum amount of deformation of the net body 14 is large, the degree of protrusion of the net body 14 that has captured the falling rock R in the direction of projecting below the slope or from the slope S, that is, the amount of deformation from the set stretching position becomes large. For example, when the rockfall guard fence is close to a house or a road, if the amount of deformation of the net body 14 that captures the rockfall R from the set extension position is large, the rockfall guard fence may not function sufficiently.

FIG. 6B is a rockfall protection fence of this embodiment in which the space holding member 2 of FIGS. 1 and 2 is arranged on the rockfall protection fence of FIG. 6A. Since it is necessary for the net body 14 to capture the rockfall R that falls while floating away from the slope S, for example, the rockfall guard fence extends from the slope S to a certain height and is stretched. However, the falling rock R substantially abuts at some point in the vertical direction of the net body 14. Therefore, if the space holding member 2 which is long in the vertical direction and has a higher rigidity than the net body 14 is arranged in contact with or close to the net body 14 between the support columns 10 and the support columns 10, rock fall will occur in the net body. When colliding with 14, the kinetic energy of the falling rock R is also transmitted in the vertical direction of the net body 14 via the space holding member 2, and the transmitted portion also deforms the net body 14. That is, by disposing the long interval holding member 2 in the vertical direction along the net body 14, the deformed region of the net body 14 expands in the vertical direction, and the kinetic energy of the falling rock R is absorbed more efficiently. As a result, the maximum amount of deformation of the net body 14 becomes small, and the amount of deformation of the net body 14 that captures the falling rock R from the set upholstery position is suppressed.

Further, in this embodiment, since the length of the space holding member 2 is the same as the vertical length of the net body 14, the deformation region of the net body 14 at the time of a rockfall collision can be expanded over the entire vertical direction. The kinetic energy of the falling rock R is absorbed more efficiently. Therefore, the maximum amount of deformation of the net body 14 can be further reduced, and the amount of deformation of the net body 14 that captures the falling rock R from the set stretching position can be further reduced. Further, since the rigidity of the space holding member 2 is larger than that of the net body 14 and smaller than that of the support column 10, the space holding member 2 is deformed after the net body 14 is deformed and before the support column 10 is deformed, and the space holding member 2 is deformed. The kinetic energy of the falling rock R can also be absorbed by the deformation of the member 2. In the actual rockfall protection fence, even if the strength of the support column 10 is increased as described later, the support column 10 is slightly deformed to the slope valley side due to the kinetic energy of the rockfall R, as shown by the two-dot chain line in the figure. Or you may be inclined. In this embodiment, hereinafter, it is referred to as tilting of the support column 10 downward on the slope at the time of capturing rockfall, including the deformation of the support column 10 toward the slope valley side.

FIG. 7 is an explanatory view schematically showing a state in which the rockfall R is captured by the rockfall guard fence of the embodiment shown in FIGS. 1 and 2. Specifically, FIG. 7A is FIG. 6 (A). B) is a plan view, and FIG. 7 (B) is a front view of the slope of FIG. 6 (B). The net body 14 illustrates only a part. As is clear from the figure, in the rockfall protection fence of this embodiment, the net body 14 is deformed over the entire vertical direction by the space holding member 2, and as a result, the maximum amount of deformation of the net body 14 is small. Further, since the proximity between the upper portions of the columns is restricted by the tension rod member 16 having a predetermined rigidity arranged between the upper portions of the adjacent columns 10, the net body 14 does not loosen unnecessarily, whereby the net body 14 does not loosen unnecessarily. However, the amount of deformation of the net body 14 from the set tension position is suppressed. Due to these actions, in the rockfall protection fence of this embodiment, the amount of deformation of the net body 14 that captures the rockfall R from the set upholstery position is small. Therefore, for example, it can be installed near a road.

8 is a perspective view of the connecting structure of the tension member 16 and the tension member 6 of the rockfall protection fence of FIGS. 1 and 2, and FIG. 9 is a three-view view of the connecting structure of FIG. 8 (A). ) Is a partial cross-sectional plan view, and (B) is a partial cross-sectional front view. As described above, the support column 10 of this embodiment is configured by tightly inserting and fixing the H-shaped steel 38 into the steel circular pipe material (steel pipe member) 36, and the web 38a of the H-shaped steel 38 has a slope. It is arranged so as to be in the direction of the maximum slope line. As the circular pipe material 36, a material having a diameter of 273 mm was used. The maximum slope line means the direction in which the slope angle is maximized. This is because, in general, the flange of H-shaped steel with a large moment of inertia of area resists the bending moment, so the flange is arranged in the vertical direction of the slope so that the flange receives the bending moment at the time of rockfall collision, that is, the web is set to the maximum of the slope. It is set in the direction of the inclined line. Conventionally, as the support of this type of rockfall guard fence, a steel pipe material filled with concrete and solidified has been used. Although this conventional support has sufficient strength (rigidity), it is heavy, difficult to handle, and difficult to construct. On the other hand, the support column 10 of this embodiment has a small weight, is easy to handle and is easy to construct, and has sufficient strength (rigidity) as a support column for a rockfall protection fence. The cross-sectional shape of the steel pipe material does not necessarily have to be circular.

In this embodiment, the tension rod members 16 are arranged not only in one place between the adjacent columns 10 but also between all the columns 10, that is, between the adjacent columns 10, and the inside of each of the support rod members 16. The tension material 6 is inserted into the shaft, and the ends thereof are connected to the adjacent columns 10. Therefore, the tension rod members 16 on both sides of the support column 10 and the connecting member 8 for connecting the tension member 6 to the support column 10 are penetrated through the support column 10, and the tension rods are stretched to each of the penetrating tip portions of the connecting member 8. The member 16 and the tension member 6 are connected to each other. The connecting member 8 is made of a material having high strength and high toughness, that is, a material that is hard to break and allows deformation, for example, a steel plate material. The connecting member 8 is a relatively long rectangular plate material, for example, a square formed on a support column 10, that is, a circular pipe material 36 and a web 38a of an H-shaped steel 38 with the plate width direction set in the vertical direction. It is inserted through the hole 41. It should be noted that the slope lateral protrusions of the connecting member 8 that further protrudes from the columns 10 at both ends in the slope lateral direction are cut off.

On the upper surface of the central portion in the longitudinal direction of the connecting member 8, for example, a tapered portion 42 having a low front side and a high back side in FIG. 8 is formed. Further, on the opposite side of the tapered portion 42, that is, on the lower surface of the central portion in the longitudinal direction of the connecting member 8, a fitting recess 44 into which the pipe wall of the circular pipe member 36 is fitted relatively tightly is formed. Therefore, after the connecting member 8 is inserted into the support column 10, that is, the square hole portion 41 formed in the circular pipe material 36 and the web 38a of the H-shaped steel 38, the pipe wall of the circular pipe material 36 is fitted into the fitting recess 44. By lowering the connecting member 8 so as to do so, the connecting member 8 is positioned on the circular pipe member 36, that is, the support column 10. In this state, when the wedge material (wedge) 43 is inserted into the hole portion 41 of the circular pipe material 36, the wedge material 43 presses the tapered portion 42 of the connecting member 8 downward, and the connecting member 8 presses against the circular pipe material 36. As a result, the connecting member 8 is engaged (fixed) to the support column 10.

The ends of the tension member 6 erected between the adjacent columns 10 are firmly connected to each of both ends of the connecting member 8 in the longitudinal direction. For the tension material 6, for example, a high-strength steel wire cable is used. In this embodiment, for example, a steel wire cable having an outer diameter of 18 mm is used as the tension material 6, but the specifications of the tension material 6 are not limited to this. The tension material 6 originally suppresses the support column 10 from tilting downward on the slope at the time of a rock fall collision. In addition to this, steel wire cables, as is well known, have high tensile strength, but also high elasticity with respect to tensile force. Therefore, as will be described later, when the energy at the time of a rockfall collision acts on the connecting portion between the support column 10 and the tension rod member 16 from the net body 14 that has captured the rockfall, the tension material 6 made of a steel wire cable expands and contracts ( (Mainly stretched), the energy is absorbed, and it becomes possible to suppress the breakage of the connecting structure between the support column 10 and the tension rod member 16. It is desirable that no tension acts on the tension member 6 or only a very small tension acts on the tension member 6 in a state where the support column 10 is not tilted downward on the slope.

The tension rod member 16 is fitted on the outside of the tension member 6 and the connecting member 8, and is formed at each of a hole (not shown) formed at the end of the tension member 16 and both ends of the connecting member 8 in the longitudinal direction. The screw shaft member 46 is inserted into the slotted hole 45, and the nut member 47 is screwed and connected to the insertion protrusion of the screw shaft member 46, whereby the end portion of the tension rod member 16 is connected to the support column 10 via the connecting member 8. Is linked to. That is, in this embodiment, the tension rod member 16 and the tension member 6 are connected to the support column 10 via the common connecting member 8. Therefore, as described above, when the energy at the time of a rock fall collision acts on the connecting structure of the support column 10 and the tension rod member 16 from the net body 14 that has captured the falling rock, the tension material 6 sharing the connecting member 8 immediately acts. It expands and contracts (mainly expands), whereby energy at the time of a rock fall collision is efficiently absorbed, and as a result, breakage of the connecting structure between the support column 10 and the tension rod member 16 can be effectively suppressed.

Further, in this embodiment, since the connecting member 8 allows deformation, the energy at the time of a rock fall collision is also absorbed by the deformation of the connecting member 8, and the breakage of the connecting structure between the support column 10 and the tension rod member 16 is suppressed. To. Further, as described above, since the support column 10 also tilts to some extent at the time of a rock fall collision, the tension material 6 erected between the adjacent columns 10 also expands and contracts (mainly) as the support column 10 tilts at the time of this rock fall collision. (Elongation), the energy at the time of a rock fall collision is also absorbed, and the breakage of the connecting structure between the support column 10 and the tension rod member 16 is suppressed. If the breakage of the connecting structure between the support column 10 and the tension rod member 16 can be suppressed, the tension rod member 16 can continue to regulate the upper portions of the adjacent columns 10 from being close to each other. The amount of deformation from the set tensioning position of 14 can be reduced.

When the net body 14 captures the falling rock, the energy at the time of the rock falling collision acts as a bending moment or a shearing force from the net body 14 to the connecting portion between the tension rod member 16 and the support column 10. Simply increasing the strength (rigidity) of the tension rod member 16 and the support column 10 with respect to this energy has little effect of absorbing or attenuating it. The energy transmitted from the net body 14 at the time of a rockfall collision acts to tilt any of the columns 10. At this time, in the column 10 that is tilted and the column 10 that is not tilted, the distance between the upper portions of the columns 10 becomes large because the upper portions of the columns 10 are separated from each other. At that time, the tension material 6 erected between the upper portions of the columns 10 suppresses the inclination of the columns 10 to be tilted, and the tension material 16 is mainly stretched to transmit the tension material 16 to the columns 10 to be tilted. It is possible to absorb the energy at the time of a rock fall collision, and thereby it is possible to suppress the breakage of the connecting portion between the support column 10 and the tension rod member 16. It should be noted that the tilting of the support column 10 at the time of catching rockfall is also suppressed by the tension rod member 16 arranged between the adjacent support columns 10 via the connecting member 8.

As the net body 14 described above, the ring type net described in Patent Document 1 described above can also be used. In this ring-type net 18, for example, as shown in FIG. 10, four ring-shaped members 20 are evenly arranged around one ring-shaped member 20, and the inner peripheral side of the ring-shaped members 20 is arranged. Connect so that they are in contact with each other. The connecting structure of the ring-shaped member 20 has various forms.

The ring-shaped member 20 is configured by winding, for example, a wire rod made of a steel wire a plurality of times (5 to 20 times) and tightening several places in the circumferential direction with fasteners. The fastener is, for example, a substantially cylindrical metal fitting having a C-shaped side surface, and is fixed by covering the outside of the wire rod polymerized by winding and then crimping. The ring-shaped member 20 adjusts the strength and energy absorption force at the time of deformation, which will be described later, by adjusting, for example, the material of the wire, the diameter of the wire, the number of windings of the wire, the tightening force by the fastener, and the like. Can be done.

As the wire rod constituting the ring-shaped member 20, for example, a steel wire manufactured from a hard steel wire rod is preferable, but for example, an iron wire manufactured from a mild steel wire rod may be used. In the case of steel wire, a steel wire having a tensile strength of 800 N / mm ² or more is preferable. Further, those obtained by plating or coating these wires can also be used. More preferably, the ring-shaped member 20 is made of the hard steel wire rod used for the above-mentioned rhombic wire mesh. The wire diameter of the wire rod is about 2.5 to 5 mm, and the diameter of the ring-shaped member 20 is set according to the size of the rock fall to be captured. By changing the diameter of the ring-shaped member 20, the ring-type net 18 can easily correspond to the size of the rock fall to be captured. For example, by investigating the size of rocks and gravel on the slope S and setting the diameter of the ring-shaped member 20 according to the size, it is possible to effectively capture the falling rock when the rock falls.

In the ring-type net 18 formed by connecting the ring-shaped members 20, for example, when a force (load) perpendicular to the net surface is applied, the ring-shaped members 20 are pulled together, so that the shape of the ring-shaped member 20 itself is deformed. At the same time, the wire rod constituting the ring-shaped member 20 is deformed so as to loosen the winding. These deformations occur when the kinetic energy of falling rocks, specifically, the falling rocks collide and a load acts on the net surface, and when a load is applied to the ring type net 18, the ring-shaped member 20 is deformed, resulting in falling rocks. The kinetic energy of the ring is absorbed, and as a result, the effect of capturing rockfall with the ring net 18 is obtained.

Therefore, the force required for the deformation of the ring-shaped member 20, in other words, the kinetic energy of the falling rock that can be absorbed by the deformation of the ring-shaped member 20, is, for example, the material, wire diameter, and number of turns of the wire rod constituting the ring-shaped member 20. Alternatively, it can be adjusted by the tightening force of the wire rod by the fastener.

As described above, according to the rockfall protection fence of this embodiment, a plurality of columns 10 are erected at predetermined intervals in the lateral direction of the slope, and the net body 14 is supported by the columns 10 to support the columns 10. In the case of stretching between the columns 10, both ends of the tension material 6 for restricting the separation of the adjacent columns 10 from each other are connected to the upper part of the columns 10 and the tension material 6 is erected between the adjacent columns 10. do. As a result, when the net body 14 catches rockfall and the strut 10 tries to tilt due to the energy of the rockfall collision transmitted from the net body 14, the tension material is separated from the adjacent strut 10 on the upper part of the strut 10. It can be regulated by 6. Therefore, the tilting of the support column 10 to be tilted downward on the slope is suppressed, and as a result, the amount of deformation of the net body 14 that has captured the falling rock from the set extension position can be suppressed.

Further, a tension rod member 16 having a predetermined rigidity and restricting the upper portions of adjacent columns from being close to each other is arranged between the upper portions of the adjacent columns 10 substantially parallel to the tension member 6. As a result, when the net body 14 catches the falling rock and is pulled by the net body 14, and the upper portions of the adjacent columns 10 on both sides supporting the net body 14 try to approach each other, the columns The proximity of the upper part of 10 is regulated by the tension rod member 16. Therefore, it is possible to avoid unnecessary slackening of the net body 14, and it is possible to reduce the amount of deformation of the net body 14 that has captured the falling rock from the set tensioning position.

Further, by inserting the tension material 6 into the tubular tension rod member 16, the tension material 6 and the tension rod member 16 can be arranged at the same position, so that any one of the adjacent columns 10 can be arranged. It is possible to efficiently regulate tilting and trying to separate, or the upper part of both from approaching, and this allows the amount of deformation from the set tension position of the net body 14 that captured the falling rock in any situation. Can be made smaller. Further, the tension material 6 can quickly and efficiently absorb the energy transmitted from the net body 14 that has captured the rockfall to the connecting portion between the strut member 16 and the strut 10, whereby the strut member 16 and the strut 10 can be absorbed. It is possible to suppress the breakage of the connecting structure, avoid unnecessary slackening of the net body 14, and maintain a small amount of deformation of the net body 14 from the set tension position that captures the falling rocks.

Further, the tension member 6 was connected to the support column 10 via a connecting member 8 which was fixed to the support column 10 and deformed at the time of a rock fall collision to absorb energy, and the end portion of the tension rod member 16 was connected to the connecting member 8. .. As a result, the breakage of the connecting structure between the tension member 16 and the support column 10 due to the energy of the rockfall collision transmitted from the net body 14 that has captured the falling rock can be suppressed by stretching the tension member 6 and deforming the connecting member 8. As a result, the function of the tension rod member 16 is maintained, and the amount of deformation of the net body that has captured the falling rock from the set tension position can be kept small. Further, the tension material 6 and the tension rod member 16 can be simply connected to the support column 10 in a state where the tension material 6 is inserted into the tubular tension rod member 16, and the cost and weight are reduced by that amount. be able to.

Further, when the tension member 6 is erected between the adjacent columns 10 and the tension rod member 16 is arranged between the adjacent columns 10, the connecting member 8 is penetrated in the left-right direction of the slope of the column 10 and the penetrating portion thereof. The end of the tension member 6 and the end of the tension rod member 16 between the adjacent columns 10 were connected to each other. As a result, the tilting of the support column 10 pulled by the net body 14 that has captured the rockfall can be further suppressed by the tension member 6 and the tension rod member 16 between the adjacent support columns 10, so that the tilting of the support column 10 can be further suppressed. It is possible to suppress the breakage of the connecting structure between the support column 10 and the tension rod member 16, and thereby further reduce the amount of deformation of the net body 14 that has captured the falling rock from the set tensioning position. be able to.

Further, the H-shaped steel 38 is inserted into the circular pipe material 36 to form the support column 10, and the web 38a of the H-shaped steel 38 is arranged in the direction of the maximum inclined line of the slope, and the circular pipe material 36 and H are arranged. The connecting member 8 is arranged so as to penetrate the web 38a of the shaped steel 38. As a result, the strut 10 has sufficient strength (rigidity) against the load transmitted from the net body 14 that has captured the fallen rock at the time of a rockfall collision, so that the tilting of the strut 10 itself is reduced or suppressed, and the rockfall is prevented. The amount of deformation of the captured net body 14 from the set stretching position can be reduced. In addition, the weight of the support column 10 can be reduced, and the support column penetration structure of the connecting member 8 can be simplified, resulting in easy construction.

Although the embodiments have been described above, the configuration of the present invention is not limited to these embodiments, and various modifications can be made within the scope of the gist of the invention. For example, the number and materials of the above-mentioned lateral reinforcing rope 26 and the spacing member 2 are appropriately selected according to the situation at the site, and the braking devices thereof are limited to the above-mentioned configuration. Instead, any rope may be used as long as it allows the lateral reinforcing rope 26 and the connecting rope 6 to stretch with a braking force.

Further, in the above-described embodiment, only one net body 14 is stretched between the columns 10 at both ends in the lateral direction of the slope, but for example, the net body 14 may be stretched between each of the columns 10.

Further, the application of the present invention is not limited to the case of newly constructing on the slope S, but it is also possible to install the support column 10 and the net body 14 on the foundation of the existing rockfall protection fence by the structure of the present invention.

2 Spacing member 6 Tension material 8 Connecting member 10 Strut 12 Concrete structure 14 Net body 16 Strut rod member 18 Ring type net (net body)
22 Rhombus wire mesh (net body)
36 Circular pipe material (steel pipe member)
38 H-section steel S slope

Claims (5)

A plurality of columns erected on the slope at predetermined intervals in the left-right direction of the front view of the slope, and
A net body that is supported by the plurality of columns and is stretched between the columns,
In a rockfall guard rail equipped with
A tension material that regulates the movement of the adjacent columns in a direction away from each other is erected between the adjacent columns.
The tension material is erected between the upper parts of the adjacent columns, and the tension material is erected.
A bracing rod member having predetermined rigidity and restricting the upper parts of the adjacent columns from approaching each other is arranged between the upper portions of the adjacent columns substantially parallel to the tension material.
The tension material allows at least elongation and
The rockfall protection fence is characterized in that the tension rod member is connected to the support column with a predetermined play in the extension direction . The tension rod member is a tubular body and has a tubular body.
The rockfall protection fence according to claim 1 , wherein the tension material is inserted into the inside of the tubular tension rod member. The tension material is
It is fixed to the support and is connected to the support via a connecting member that absorbs energy by deforming at the time of a rock fall collision.
The rockfall protection fence according to claim 2 , wherein the end portion of the tension rod member is connected to the connecting member. When the tension material is erected between the adjacent columns and the tension member is arranged between the adjacent columns, the connecting member penetrates the column in the left-right direction of the slope and penetrates the penetrating portion. The rock fall protection fence according to claim 3 , wherein the end portion of the tension material erected between the adjacent columns and the end portion of the tension rod member arranged between the adjacent columns are connected to each other. .. The column is configured by inserting an H-shaped steel inside a steel pipe member, and the web of the H-shaped steel is arranged so as to face the maximum inclination line direction of the slope.
The rock fall protection fence according to claim 4 , wherein the connecting member is disposed so as to penetrate the steel pipe member and the web of the H-shaped steel.

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