JP6466519B2 - Rope fastener to anchor used for rockfall countermeasure and method of rockfall protection net work using this - Google Patents

Description

  The present invention relates to a rope fastener to an anchor fixed to a slope used for rockfall protection net work for rockfall countermeasures.

  Rock fall countermeasures include rock fall prevention work that removes, fixes and deters sources, and rock fall protection works aimed at preventing damage caused by the fall rocks (Road Earth Cut and Slope Stabilization Guidelines Public Interest Incorporated Association Japan Road Association 2009 edition p339).

  One of the rock fall prevention works is wire rope hanging work. This can be done by directly covering or hanging the base of floating stones using a wire rope or several wire ropes that are latticed so that the rocks and rolling stones on the slope do not slide or fall. It is a thing (Japan Road Association p104). Since both ends of the wire rope are fixed to the anchor, it is necessary to select a stable fixing ground for the anchor, and the wire rope and the anchor must withstand the mass of floating stones and the load at the time of sliding. This method is used when a rock block on the target slope is specified. To fix the rock block on the slope, wire rope is hung without slack, and multiple wire ropes are hung. The tension of each wire rope is desirably equal.

  Furthermore, rock fall prevention works include rock fall protection net work as a countermeasure when there are wide and unspecified unstable rock blocks on the slope, and this construction method is similar to the overturning rock fall protection net positioned as rock fall protection work. (Same handbook p126, p133). Covered rockfall protection nets are designed to prevent rockfalls that have lost the bond between the natural ground and the rocks by the frictional force between the metal net and natural ground on slopes where small rockfalls are likely to occur. In such a case, the falling rocks will not jump (Handbook p84, p134). This construction method covers a certain range of slopes by covering the slope in a grid with a plurality of vertical wire ropes in the vertical direction and a plurality of horizontal wire ropes in the vertical direction of the entire slope to be protected against falling rocks. Prevention and protection from falling rocks. In this vertical and horizontal rope hook, anchors are arranged at the end of the rope and at the intersection of the vertical and horizontal ropes. Protected. Furthermore, as countermeasures against collapse smaller than the lattice scale formed by the vertical and horizontal ropes, auxiliary ropes are stretched or the slopes are covered with a wire mesh coupled to the ropes.

  The interval of the grid is generally about 2m x 2m, and about 50cm vertically and horizontally in the grid (In this specification and drawings, only auxiliary ropes with 1m intervals are displayed, and other auxiliary ropes and wire mesh are omitted. Auxiliary rope is provided. An anchor is installed at the end of the main rope, thereby ensuring a reaction force against the tensile force of the main rope. Anchors are installed at the intersections of vertical and horizontal main ropes, and clips are provided on the anchor heads to fix the cross sections of the vertical and horizontal ropes. The conventional construction method of such a covered rockfall protection net has a structure mainly intended to drop the fallen rocks along the slope without jumping, in addition to being effective for rockfall prevention.

  In order to improve the working efficiency and reduce the heavy burden compared to the conventional rock fall protection net construction method as described above, in Patent Document 1, a roller or the like is used for rope mooring at an intermediate anchor, and the tension of the rope We propose a method that can be transmitted over the entire length of the rope.

  Patent Document 2 proposes a grid-like rope net work with an inclination in order to cope with various undulation shapes on the inclined surface to be constructed, compared to a conventional grid-like net formed in the horizontal and vertical directions. Has been.

JP 2014-152551 A JP 2015-121037 A

Road earthwork-Cut and slope stabilization guidelines (2009 edition) published by Japan Road Association Falling rock countermeasure manual (June 2000) Japan Road Association publication

  In the rock fall protection net work, as shown in FIG. 10, in order to cover the entire slope having the unstable rock mass 11, a vertical or horizontal rope anchor 27 is provided at the edge portion, and a vertical or horizontal shape is provided at the intermediate portion. Anchor 29 is installed at the intersection of the ropes. A vertical main rope 31 that is a wire rope 3 connected in the vertical direction and a horizontal main rope 32 that is a wire rope connected in the horizontal direction are stretched to be connected to the edge anchor 27, and at the intermediate portion, the intersection of the vertical and horizontal ropes Is fixed to the anchor. It has considerable skill in stretching a rope hook in a lattice shape of a certain size with a plurality of vertical main ropes and horizontal main ropes without slacking with the same degree of tension, and it is unstable due to the tension of the rope It may be difficult to fix a rock block on a slope due to the unevenness of the slope. Moreover, the edge part anchor pin 41 has the role which connects with the anchor of the wire rope of one direction in either the vertical or horizontal direction. The cross anchor pin 42 fixed to the intermediate anchor 29 has a function of fixing a vertical and horizontal wire rope to the cross at an intermediate point of continuous wire ropes. The construction range of such a conventional construction method may include edge portions that do not require construction and grid-like portions (A, B, C, D) that do not require prevention.

  A rope fastener to an anchor used for rope fall prevention against falling rocks on a slope, and a plurality of anchor holes through which a shaft fixed to the anchor protrudes on the slope in the center and through which the rope is connected. A rope fastener comprising a rope connecting hole and being a rotatable body rotatable with respect to the shaft body.

  The rope fastener, wherein the anchor hole is a long hole having a longitudinal direction.

  The fastener of the present invention can be used for both the end portion and the intermediate portion, so that the rope can be shortened as necessary with respect to the conventionally used continuous rope. Meanwhile, the load applied to one rope can be distributed to other ropes in the vicinity and anchors in the vicinity. Therefore, it is possible to easily apply an appropriate pressing force to unstable rock masses by the tension of the rope, and to enable efficient and effective construction as a rock fall prevention work using a rock fall protection net that is a rock fall protection work. be able to. Specifically, a conventional edge anchor is unnecessary at the end, the construction area can be reduced, and an overturned rockfall protection net that can efficiently cover an unstable slope can be installed. In the middle part, by using the fastener of the present invention, it is possible to exert an appropriate pressing force on the unstable rock mass according to the shape of the uneven surface of the target slope, The function of can be greatly improved.

FIG. 1 is an explanatory view showing an example of use of a rope fastener for a lock bolt. (Example 1) FIG. 2 is an explanatory view showing a rope fastener for a lock bolt. (Example 1) FIG. 3 is an explanatory view showing a rope fastener having a rope connecting hole and a rope through hole and an example of its use. (Example 1) FIG. 4 is an explanatory view showing a rope fastener used in combination with a rope clip and an example of its use. (Example 1) FIG. 5 is an explanatory view showing a rope anchor for a pipe anchor and an example of its use. (Example 2) FIG. 6 is an explanatory diagram of the effect on the anchor hole of the rope fastener. FIG. 7 is an explanatory diagram of the effect on the rope connection to the anchor in the recess. FIG. 8 is an explanatory view showing a rock fall protection net work using a rope fastener. Example 3 FIG. 9 is an explanatory view showing a rock fall protection net work using a rope fastener on an uneven slope. (Example 4) FIG. 10 is a construction diagram of a conventional covered rock fall protection net.

  The rope shown in the mode for carrying out the invention is a wire rope 3 that is generally used in a cover-type rock fall protection net. Usually, the anchors are different between the rock part and the earth and sand part, but Example 1 shows a case where it is implemented with a rock bolt for rock part, and Example 2 shows a case where it is implemented with a pipe anchor for earth and sand part. In Example 3 and Example 4, a rock fall protection net work or a cover type rock fall protection net utilizing the rope fastener of the present invention is shown.

  By using the fastener of the present invention, the anchor and the rope can be connected in various forms. However, in consideration of the fact that conventionally a single continuous rope was used at the same vertical position or the same horizontal position, the vertical and horizontal ropes to the rope connection hole are related to the relationship between the anchor and the rope at the anchor position. Since the tension generated by falling rocks, etc. due to the connection with the rope can be the tension between the rope connection holes facing each other across the anchor hole and between the anchor hole and the rope connection hole, these tensile strengths are the same as the tensile strength of the rope. It is desirable to have the same or higher strength.

  FIG. 2 shows several rope fasteners 4 of the present invention when the rock bolt 21 for rock is used as an anchor. In this embodiment, the shaft body 23 fixed to the anchor is obtained by processing the head of the lock bolt 21. The rope fastener shown in FIGS. 2 (1) to (3) has an anchor hole 44 that is a circular hole at the center, and a lock bolt head that protrudes on the slope penetrates. The anchor hole has a diameter that can be easily rotated with respect to the diameter of the anchor fixing shaft body 23. FIG. 2 (1) shows an intermediate portion rope fastener, which has circular rope connecting holes 46 in four vertical and horizontal directions on a peripheral portion of a rotating body 45 having anchor holes as bearings. FIG. 2 (2) is an end side rope fastener, two rope connecting holes facing each other with the anchor hole sandwiched in the end side direction and the anchor hole on the periphery of the rotating body in a direction perpendicular to the end side direction. A rope connection hole is provided. Fig. 2 (3) shows a rope clamp for a corner, which is provided in a direction opposite to the resultant force generated by a rope connecting hole provided in a perpendicular direction with the anchor hole as a vertex. Accordingly, a rope connection hole that can be connected to the rope from the corner anchor 30 is provided. FIGS. 2 (4) to (6) are diagrams in the case where a long anchor hole is employed in the intermediate rope clamp. FIG. 2 (4) shows a rope fastener having anchor connection holes of straight long holes with the anchor holes having a longitudinal direction between the rope connection holes facing each other. FIG. 2 (5-1) is a rope fastener in which the anchor hole is a linear long hole in the longitudinal direction having an inclination with respect to the opposite rope connecting holes. FIG. 2 (5-2) shows a fastener when the anchor hole is a curved long hole. FIG. 2 (6) shows a rope fastener having a plurality of anchor holes having overlapping portions. These rope fasteners are obtained by cutting a structural rolled steel material and can be used freely.

  In FIG. 1, the case where the rope fastener 4 of FIG. 2 (1) is installed in the anchor by the lock bolt 21 is shown. The anchor fixing shaft body 23 is provided with a spiral groove (not shown in the drawing) and a retaining nut 25 is installed in order to prevent the rope fastener from coming out of the shaft body. A base 24 for the rope fastener is provided on the lock bolt fixing member 26. This is to ensure the function of the fastener as a rotating body. The rope 3 is connected to the rope connection hole 46 provided in the vertical and horizontal peripheral edge portions of the rotating body 45. In the example shown in FIG. 2 (1), the two directions are connected by a rope whose end is processed, and a pin of the shackle 35 penetrates through another rope connecting hole facing them, and the rope is connected to the rope at the other end of the shackle. It is connected. Although not shown, the rope may be connected through a turnbuckle.

With reference to FIG. 6, the fixation of the unstable rock mass to the slope by the rope hooking will be described as being out of scope with respect to the anchor and with respect to the drawing direction load. In FIG. 6 (1), the rope stretched in a loose state between the fixed point A and the fixed point B with respect to the unstable rock mass X has a length of L ₀ , and the unstable rock mass X the Henjo happened, the rope becomes L ₁ when the state of Y, the stress corresponding to the distortion becomes rope tension act on the rope (T), further variations of unstable rocks Y It acts in the direction to suppress the state. In FIG. 6A, σ is a stress when the rope is an elastic body, and E is an elastic coefficient. 6 (2), the operation when the fastener of the present invention is installed using the fixed point A as an anchor will be described. The rope without the original slack is in state o. When deformation occurs in the unstable rock mass, the rope is in state p if the fastener is fully fixed to the anchor without rotating. When the fastener is a rotating body and no resistance moment acts on the rotation, in the state r, when the resistance moment acts by a rope connected to another rope connection hole, the state becomes q. The resistance moment in this case is caused by the eccentric distance α in the figure and the tension generated by other ropes. In the state of p, in addition to the lateral force, a load acts on the anchor in the direction in which the anchor is twisted, and an undesirable load is generated on the anchor. In the case of r, the tension acting on the rope acts as a lateral force on the anchor as it is, but in the case of p, the tension on the other rope relaxes the lateral force due to the tension between AB acting on the anchor. It acts in the direction to do.

Next, the operation when the anchor hole of the fastener is a long hole will be described. As shown in FIG. 6 (3), a fastener having an elongated anchor hole of the present invention is installed in A and B, and the anchor fixing shaft body is located at the center of the elongated hole between CA and AB. When the tension of the rope between the BD and the BD is adjusted, if the change in the length of the rope accompanying the deformation of the rock mass as shown in FIG. 6 (1) is within the length w in the longitudinal direction of the long hole (w > L ₁ −L ₀ ), the tension acting on the rope between AB can all be transmitted between AC and BD. As apparent from comparing the tension (T) obtained from the stress shown in FIG. 6 (1) and the tension (T ′) obtained from the stress shown in FIG. The acting tension is reduced.

  When the anchor hole 44 is a long hole, it does not necessarily have to be in the direction of the rope connecting hole 46 that faces each other as shown in FIG. For example, it can be as shown in FIG. The length w of the long hole can be increased, and when a tensile force is applied, a rotational force is applied to the fastener at the same time. In this case, the effect of the rotation can be exhibited. As the anchor hole, not only a straight elongated hole in a single direction but also a curved elongated hole as shown in FIG. By adjusting the tension of the rope acting on the fastener, the anchor shaft body may be easily retained at a predetermined position in the anchor hole. In FIG. 2 (6), a fastener having a plurality of long holes having overlapping portions as anchor holes can quickly cope with the tension direction that is superior to the tension direction of the ropes in the vertical and horizontal directions. Because.

  In FIG. 3, the rope fastener 4 provided with the rope connection hole 46 and the rope through-hole 47 in the rotary body 45, and its use condition are shown. Fig. 3 (1-1) shows a plan view of the rope fastener, Fig. 3 (1-2) shows a front view, and Fig. 3 (1-3) shows a cross-sectional view along AA. The rope through hole is a circular hole having an inclination with respect to the planes of the anchor hole 44 and the rope connection hole, and has the same diameter as the rope connection hole. FIG. 3 (2), (3), and (4) show usage diagrams. As shown in the plan view of FIG. 3 (2), when viewed from the left end side of the rope, it passes through the first rope through hole from the lower side, passes through the upper surface of the rope fastener, It penetrates downward from the upper side and extends to the right end side. A lock bolt head 23 passes through the anchor hole, and a retaining nut 25 is provided. In the case of this example, only the shackle 35 is displayed in the rope connection hole. The rope passing through the rope through hole is constrained at the passing point by the rope fastener supported on the anchor fixing shaft. In this case, the effect of the rotation of the rope fastener is as described above, and is due to the bending elasticity of the rope. Resistance also works. At the same time, this rope exhibits the same effect as FIG. 6 (3) as a wire between fixed points at both ends of the rope (not shown). FIG. 3 (5) shows a fastening tool for fastening and fixing a rope passing through the through hole. This tightening tool can also fix the penetrating rope at the position of the main through hole.

  FIG. 4 shows an embodiment of the rope fastener 4 in which a rope clip 48 for fastening and fixing a rope used together with the rope connection hole 46 is attached. FIG. 4A is a plan view showing a situation in which a rope fastened and fixed to a rope clip is used at an end portion. As shown in FIG. 4 (1), the clip has a clip metal fitting fixed with two screws by holding the rope in two places of the rotating body, and the metal fitting is a rope as shown in the side view of FIG. 4 (3). It consists of a semicircular part that presses and a flat plate part that has screw holes. By tightening the two screws, the rope is fastened and fixed by friction between the semicircular portion of the clip fitting and the rotating body. As shown in FIG. 4A, there are an anchor hole 44 and a rope connecting hole in a direction perpendicular to the fastened and fixed rope, and a shackle pin passes through the rope connecting hole. Although not shown, a rope is connected to the other end of the pin of the shackle. With respect to the rope fastener used in combination with the rope clip, the rotation effect of the anchor hole is the same as described above, but in the case of the rope clip, resistance due to the bending elasticity of the rope also works. Moreover, a long hole and an overlapping hole can be adopted as an anchor hole for a rope fastener used in combination with a rope clip.

  Fig. 5 (1-2) shows the rope fastener 4 when the pipe anchor 22 is used as an anchor at the earth and sand part. The anchor hole 44 has a diameter through which the pipe anchor head penetrates and the rope fastener can be rotated. The anchor hole 44 is larger than that of the lock bolt, and the outer diameter of the rope fastener is also increased. The diameter of the rope connection hole 46 arranged in the three directions of the peripheral edge of the rotating body 45 is the same as that of the lock bolt shown in FIG. FIG. 5 (1-1) and FIG. 5 (2) show a state in which the rope fastener is used for the pipe anchor at the end portion. The head of the pipe anchor is passed through the anchor hole of the rope fastener as the anchor fixing shaft body 23. The function of the rotator base 24 is the same as that of the lock bolt, but the retaining bolt 251 provided on the anchor head is used for retaining.

  FIG. 5 (4) shows an embodiment in which the head of the pipe anchor 22 is machined and the fixed shaft installation body 232 having the anchor fixing shaft body 23 having the same diameter as the head of the lock bolt 21 is provided. FIG. 5 (3) shows a cross-sectional view of a state where the fixed shaft installation body is fitted to the pipe anchor head and the installation body retaining bolt 233 is provided. The fixed shaft installation body is obtained by attaching an anchor fixed shaft body that is erected in the center of the lid portion of the interior pipe with lid 232, passing through the installation anchor retaining bolt through the pipe anchor and the interior pipe, and fixing with a nut. Accordingly, the rope fastener for the lock bolt shown in FIG. 2 can also be used for the pipe anchor for earth and sand, and the use for making the anchor hole 44 a long hole becomes easy.

  The present invention relates to a rockfall prevention network for rockfall prevention or a rockfall protection netting system for rockfall protection (hereinafter referred to as a rockfall protection network, etc.), which enhances the function of fixing the rock block to the slope 1 for more efficient construction. Can be implemented. In this embodiment, attention is paid to the relationship with efficient and economical construction.

  FIG. 8 shows a rock fall protection net work or the like provided with the fastener of the present invention. Locations with unstable rock masses on the slope About the grid-like rope net covering this, the rope clamps 4 for the end sides are attached to the anchor 28 installation locations on the upper side, the lower side, the right side and the left side which are the end sides. The corner rope clamps are arranged at the corners formed by the upper and lower sides and the right and left sides. In the example shown, corner anchors 30 are arranged at the corners of the upper side and the right side, and tension is applied to the rope fastener in an oblique direction. FIG. 8 is compared with FIG. 10 of the conventional method. The edge anchor 27 of the conventional method is no longer necessary, the edge anchor 28 is installed in the external area close to the unstable rock mass area, and the edge anchor 27 is not formed in the grid section formed by the vertical and horizontal main ropes in FIG. Ranges (A, B, C, D) where no stable area exists are outside the scope of construction.

  By removing the construction range of the edge shown in FIG. 10 from the construction range by the rock fall protection net work etc. in which the rope fastener 4 of the present invention is arranged, the vertical and horizontal rope lengths are shortened, and the number of anchors installed is reduced. Construction costs can be reduced by reducing the necessary land area. In addition, regarding the A and B lattice areas excluding the construction range shown in FIG. 8, when a falling rock is generated above, it is immediately constructed if the falling rock protection function of preventing jumping and dropping along the slope is left. Although it cannot be excluded from the scope, it can be omitted when there are other rockfall protection measures or when it is determined that there is no need to take protective measures by this preventive work, and construction costs can be further reduced.

  FIG. 9 shows a case where rock fall protection net work or the like is constructed when a relatively large recess 13 exists in an area where the unstable rock mass 11 exists. In the conventional method, even if the rope is stretched in a lattice shape as shown in FIG. 10, the pressing force due to the tension of the rope against the unstable rock mass in the recess may not work, but the anchor is located near the deepest part of the recess. By installing 2 and the rope fastener 4 of the present invention, it is possible to easily apply tension to the rope between the peripheral anchors, and it is possible to stretch the rope in close contact with the slope. In the example shown in FIG. 9, the vertical main rope 31 and the horizontal main rope 32 are connected to the point E by replacing the cross anchor pin 42 of the conventional method with the rope fastener in the four directions for the intermediate portion of the present invention. At point F, the cross rope 43 of the conventional auxiliary rope and the main rope is replaced with a rope fastener in the four directions for the intermediate portion after the anchor is provided, and the main rope and the auxiliary rope are connected. At points G and H, a new anchor is provided, and a rope fastener provided with two rope connection holes 46 only in the lateral direction is installed to connect the main rope. At point I, a new anchor is provided at the intersection of the vertical and horizontal auxiliary ropes, and this rope fastener is installed. In general, a rope having the same standard as the main rope is used as the auxiliary rope, and there is no problem in strength even if it is connected to the anchor fastener. By adopting the rope fastener of the present invention, the number of anchors is simply increased in the description of this section, but the anchors that are unnecessary in the overall plan can be excluded. For example, by providing an anchor at the most effective F point, it is necessary to consider changing the cross anchor to the cross pin except for the left and right anchors, and changing the nearest anchor to the cross pin.

The rope is basically used as a member having only a tensile resistance, and the explanations of “0019” to “0020” are within that range. If the section used is long enough for the cross-sectional shape, its properties are outstanding. However, when the use section is short, the elastic modulus (E) of the material and the secondary moment (I) of the cross section in the cross section affect the handling of the rope as the bending stiffness (E × I). For example, as shown in FIG. 7, in the recess of the undulating natural ground, to anchor connecting the rope in the absence of slack, in a short period to L _S so shown in FIG. 7, by adding a tension to the rope anchor Is connected to the rope by a load P at the anchor connecting portion, and the rope bending resistance makes anchoring difficult, and this load P adds a large pulling force to the anchor. Will be. Even in such a case, the difficulty of anchoring due to bending resistance can be eliminated by using the fastener of the present invention.

DESCRIPTION OF SYMBOLS 1 Natural slope, 11 Unstable rock mass, 12 Unstable rock mass convex part, 13 Unstable rock mass concave part 2 Anchor, 21 Rock bolt, 22 Pipe anchor, 23 Anchor fixed shaft body, 231 Fixed shaft installation body, 232 With lid Inner pipe, 233 Installation body retaining bolt, 24 Rope clamp base, 25 retaining nut, 251 retaining bolt, 26 anchor fixing material, 27 edge anchor, 28 edge anchor, 29 middle anchor, 30 corner Corner anchor 3 Wire rope, 31 Vertical main rope, 32 Horizontal main rope, 33 Vertical auxiliary rope, 34 Horizontal auxiliary rope, 35 Shackle
4 Anchor Fastener, 41 Edge Anchor Pin, 42 Middle Cross Anchor Pin, 43 Cross Pin, 44 Anchor Hole, 45 Rotating Body, 46 Rope Connection Hole, 47 Rope Through Hole, 48 Rope Clip, 49 Rope Fastener, 50 Fastener installation hole,

Claims (6)

A rope fastener to an anchor used for rope falling against slopes on slopes,
A shaft that is fixed to the anchor protruding on the slope and extends in the longitudinal direction of the anchor;
A rotating body that has an anchor hole through which the shaft body passes in a central portion and a plurality of rope connection holes that connect a rope to a peripheral portion;
Rope fastener with A rope fastener to an anchor used for rope falling against slopes on slopes,
A shaft that is fixed to the anchor protruding on the slope and extends in the longitudinal direction of the anchor;
A rotating body that has an anchor hole through which the shaft body penetrates at a central portion, a rope connection hole that connects a rope to a peripheral portion, and a rope through hole through which the rope penetrates, and is rotatable with respect to the shaft body;
Rope fastener with A rope fastener to an anchor used for rope falling against slopes on slopes,
A shaft that is fixed to the anchor protruding on the slope and extends in the longitudinal direction of the anchor;
A rotary body having an anchor hole through which the shaft body penetrates at a central portion, a rope connection hole for coupling a rope to a peripheral portion, and a rope clip for attaching the rope;
Rope fastener with Claim 1, a rope fastener according to claim 2 or claim 3, the rope fastener anchor hole is a long hole having a longitudinal direction. A rope fastener according to claim 4, rope fasteners having a plurality of anchor holes having overlapping portions. A method of falling rock protection netting or overturning rock protection netting using the rope fastener according to claim 1, 2, 3, 4, or 5.

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