JP5571536B2 - Landslide protection work - Google Patents

Description

  The present invention relates to a landslide protection work, and more specifically, tension is applied to a rope that crawls on the ground surface, and a plurality of bearing plates arranged on the ground surface of the slope are pressed by the rope to suppress loosening and slippage of the surface layer. It relates to protective work.

  In order to prevent the slope from collapsing, tension is applied to the rope over the surface by a rock bolt anchor placed in the center of the recess recessed from the ground surface, and the rope is used to exert a pressing force on the ground surface. There is a method for stabilizing the mountain surface. This is described in, for example, JP-A-11-336082. According to this method, there is an advantage that the rope can be stretched by avoiding standing trees, but the rope tension decreases when the ground weathering, even though the intersection of the rope is in a place recessed from the ground surface I cannot deny. In particular, erosion due to the pressing of the rope is intense at the shoulder of the dent where the rope comes out of the dent, and it is not easy to recover the tension.

  Needless to say, there is a limit to the natural ground pressure only by the rope. For example, in Japanese Patent Application Laid-Open No. 2002-180472, it is proposed to place a disk-shaped bearing plate on the ground surface when placing the rock bolt anchor on an inclined ground Has been. The pressing force of the mountain surface by the bearing plate diffuses and propagates in the shape of a truncated cone having a depression angle of 45 degrees with the bearing plate as the top surface, so that the pressing area can be expanded. In addition, there are radial blades that are pushed into the surface layer under the bearing plate, and the lateral displacement is also restrained by a rope in which the bearing plate is laid vertically and horizontally, and it is expected that the durability as a slope stabilizer increases. A similar example is also disclosed in Japanese Patent Laid-Open No. 9-111761.

  As a result of the rope not exerting the action of pressing the natural ground but strengthening the mutual connection of the bearing plates, that is, when the mountain surface begins to slide, the bearing plate in the non-slip area suppresses the movement of the bearing plate in the slip area, The effect of delaying the collapse is exhibited. However, it only suppresses the expansion of the slip area at the time when the slip occurs, and the pressing force of the mountain surface by the bearing plate at the time when the slip does not occur cannot be expected originally. This is because the rope that only connects the bearing plates is given tension in the ground surface direction, but there is no portion located below the ground surface, so that the force pressing the ground surface is hardly exhibited. Because the bearing plate is on the ground surface, the rope is laid on the surface of the mountain surface at the same level as the bearing plate.

  An example in which a rope is constrained by a bottom portion of a hollow while using a bearing plate so that the bearing plate can be pressed against the ground surface by a pressing force generated on the ground surface. -106432. This is because, as shown in FIG. 15 (a), the bearing plate 21 is made into a cup shape, and the lock bolt anchor 2 is arranged in the center of the inner depression of the cup so that the cup fixing portion is lower than the ground surface. Keep it. As shown in FIG. 15B, the rope 3 laid vertically and horizontally is fixed to the anchor at the bottom of the recess, and the cup-shaped bearing plate is arranged so that the shoulder of the recess is covered. Needless to say, the rope 3 coming out from the bottom of the dent through the shoulder to the ground presses the bearing plate against the ground.

  Although the bearing plate is cup-shaped, it is arranged in the work area as shown in FIG. 15 (c), and the propagation of the pressing force to the natural ground is from the outer periphery of the cup to the ground surface as shown in FIG. It diffuses in an in-angle region 22 of about 45 degrees. Therefore, the action as the bearing plate is substantially the same as that of the non-cup disk. Since the rope only has to be locked to the collar 23 or the seat plate 24 fixed to the lock bolt anchor at the bottom of the cup, there is an advantage that the rope can be laid in an arbitrary direction, and the construction can be shortened. Greatly contribute.

  Although this cup-shaped bearing plate itself is epoch-making, the problem is that the rope tension is greatly increased depending on the suspension form of the rope that generates pressure from the bearing plate against the mountain surface. It is undeniable that there is a difference between whether or not it is possible to reduce the mutual interference at the suspension part of the rope laid vertically and horizontally. In the previous example, the rope must be stretched from end to end in the laying area in order to stabilize the suspended state. This means that the length of the rope is still required, and in addition to arranging the rope vertically and horizontally to form a rectangle by crossing, the direction of forming a diagonal line of the rectangle as shown in FIG. When the rope is also arranged, the ropes cross each other and the construction procedure is complicated. The most difficult issue is how to reduce interference between ropes.

  For example, Japanese Patent Application Laid-Open No. 2001-49673 describes an example in which a rope is made to be a triangle and shortened. In this structure, for example, the pressure bearing plate is arranged at the position of the apex of an equilateral triangle, and a rope winding cylinder is provided substantially at the center so that the rope is wound around the three winding cylinders. In this case, if the rope is wound around two bearing plates of one triangle group and the bearing plate at the apex of the triangle of the adjacent group, the ropes forming the triangle are stretched in a mesh shape. . Therefore, a predetermined work area can be covered by successively arranging units composed of three bearing plates and one triangular rope. Incidentally, the rope in each unit is provided with a turnbuckle so that both ends can be connected to generate tension.

  However, as can be seen from this explanation, two of the three bearing plates are shared by one triangular unit and the adjacent unit. That is, there are cases where only one rope is required to be hung between the two bearing plates and cases where two ropes are required to be hung. When a rope extending in a different direction is hung on a single winding cylinder, partial contact between the ropes is unavoidable, which hinders the work of applying tension in the turnbuckle. Needless to say, the rope where the two are hung can be overused. In this example as well, since the rope is wound on the upper surface of the bearing plate, the tension that can be applied to the rope cannot be solved as high as the rope that crawls out from the bottom of the depression. .

Japanese Patent Laid-Open No. 11-336082 JP 2002-180472 A Japanese Patent Laid-Open No. 9-111761 JP 2008-106432 A JP 2001-49673 A

  The present invention has been made in view of the above-described problems, and the purpose thereof is to make it possible to apply a tension that presses the ground against the rope using a recess recessed from the ground surface, and to reduce the weight of the bearing plate. In addition, it is possible to wind a shortened rope on the bearing plate, avoid laying the rope between the bearing plates, and eliminate contact between the ropes, maintain the applied tension and stabilize the bearing plate Even if the tension of the rope changes due to weathering of the mountain surface, etc., or even if there is a displacement of the bearing plate due to a small landslide, the rope can be allowed to slip while the rope is in tension. Even if a situation where the rope tension falls, the tension of the rope can be recovered and the pressure on the ground before the landslide can be maintained. That way, is to provide a landslide protection engineering which realized.

  In the present invention, tension is applied to a rope that hits the ground surface by a lock bolt anchor placed in the approximate center of the depression, and the plurality of bearing plates arranged on the ground surface of the slope are pressed by the rope to suppress loosening of the surface layer. Applicable to landslide protection works. 1 and 2, the bearing plate is a ring-shaped plate 4, and is formed in a lower part of a substantially inverted conical recess 5 formed in a natural ground at a substantially central portion of the ring-shaped plate. A roller support bracket 7 is fixed to the top of the struck rock bolt anchor 2, and three rolling rollers 6 spaced approximately 120 degrees around the lock bolt anchor 2 are attached to the roller support bracket with its shaft 6a. It is arranged and supported so as to be in the direction of the substantially normal line 5c of the substantially inverted conical surface 5a. Of the three turning rollers inside the ring plate at the position corresponding to the apex of the triangle, each winding roller 6A (see FIG. 5A) located at the opposite position in the triangle is wound. One rotated rope 3 is arranged in a triangular shape. Both ends of the rope are connected by a turnbuckle 8 on the ground surface at the intermediate position between the two ring-shaped plates 4, and approximately one third of the region S (FIG. a triangular loop is formed that holds down the portion occupying (see b). On the side where the turnbuckle 8 does not exist, a tension holder 9 that generates elasticity in a direction in which the degree of curvature is always increased in order to restore the rope tension by elastically changing the degree of curvature is provided with a rope securing portion 9a. Is intervening. Then, the triangular loop and the ring-shaped plate 4 arranged at one of its apexes are set as one unit 10 so that a large number of units arranged on the ground surface co-push the ring-shaped plate in cooperation with the adjacent unit. It is laid.

  The tension retainer is, for example, a steel rod 9A shown in FIG. 6, and the tying portion 9a may be a hook formed by bending the end of the steel rod so as to lock the rope 3 wound around the steel rod. Further, the tension retainer may be a flat steel plate 9C as shown in FIG. 11, and the lashing portion is a U bolt 15 that presses the rope 3 placed on the flat steel plate.

  Let the bearing plate be the ring-shaped plate 4S which consists of the 6 division | segmentation ring piece 4c shown in FIG. In this case, the ring pieces are connected to each other, and each of the adjacent ring pieces 4c forming an approximately one-third region is wound around the rolling roller 6 and then pressed by the rope 3 appearing on the ground surface.

  As shown in FIG. 5 (b), the bearing plate is a ring-shaped plate 4, a roller support bracket 7 fixed to the top of the lock bolt anchor 2, three turning rollers 6 spaced approximately 120 degrees apart, and a triangular shape. The rope 3 to be arranged, the turnbuckle 8 that connects both ends of the rope are provided, and a single loop 3 forms a triangular loop that holds a portion that occupies approximately one third of the region at the opposite position of each ring-shaped plate, The triangular loop and the ring-shaped plate 4 arranged at one of its apexes are set as one unit 10A, and a large number of units arranged on the ground surface are laid so as to co-push the ring-shaped plate 4 in cooperation with adjacent units. It can also be made.

  According to the present invention, since the bearing plate is a ring-shaped plate, the weight can be drastically reduced as compared with the disc-shaped bearing plate and the cup-shaped bearing plate, and a recess is formed in the surface layer of the substantially central portion inside thereof. By being able to do it, the rope can be made to wrinkle from the bottom of the depression, and the natural mountain pressing function by the ring-shaped plate can be improved by the rope tension.

  A roller support bracket is fixed to the top of the lock bolt anchor struck at the bottom of a substantially inverted conical recess formed in the ground of a substantially central portion of the ring plate, and the roller support bracket is fixed around the lock bolt anchor. Three rolling rollers with an interval of approximately 120 degrees are supported with their axes arranged in a substantially normal direction of a substantially inverted conical surface. The intended rope winding is realized, and the tension applying operation to the rope is reduced. Since the rolling rollers are arranged at intervals of approximately 120 degrees, even if there is a difference in the degree to which each roller pulls the roller, the rope wound around the other roller can supplement the pressing action of the ring-shaped plate. It is possible to exert a stable ground-holding action.

  Of the three rolling rollers inside each ring-shaped plate at the position corresponding to the apex of the triangle, one rope is wound around each of the rolling rollers located at the opposite positions in the triangle, and the shortest path is wound. Since the ropes are arranged in a triangular shape so as to follow, it is possible to shorten the ropes, and it is very easy to apply tension by the turnbuckle and easily give a predetermined value.

  The rope ends are connected by a turnbuckle on the ground surface in the middle of the two ring-shaped plates, and a single loop forms a triangular loop that occupies approximately one-third of the area at the opposite position of each ring-shaped plate As a result, the ropes do not overlap between the ring-shaped plates, and excessive use of the ropes is avoided.

  A tension holder that generates elasticity in a direction that increases the degree of curvature at all times in order to recover the rope tension by elastically changing the degree of curvature on the side where the turnbuckle does not exist, so the surface layer is weathered. Even if the mountain surface becomes thin, the looseness of the rope caused thereby is absorbed by the tension retainer. By maintaining the tension of the rope, it is possible to maintain the pressed state of the natural ground in the stage before the landslide occurs. Even if the landslide begins to occur, the rope keeps the tension, so the landslide is suppressed, and as long as the rock bolt anchor is held on the ground, the collapse of the surface layer is minimized.

  Since the triangular loop and the ring-shaped plate placed at one of its apexes are regarded as one unit, many units placed on the ground surface are laid so as to co-push the ring-shaped plate in cooperation with the adjacent unit. Even if there is a local landslide, the adjacent unit complements the anti-slip action.

  If the tension retainer is a steel rod and the hook formed by bending the end of the steel rod to lock the rope wrapped around the steel rod is used as the rope lashing portion, the rope will be separated from the steel rod. In addition, since the vine state can be maintained with the hook, the function as a tension holding device is not deteriorated. Since it is only necessary to twist a short rope to wind the steel rod, it is possible to reduce labor that is not comparable to handling a long rope covering the work area.

  If the tension retainer is a flat steel plate and the securing part is a U-bolt that presses the rope along the flat steel plate, the U-bolt hook is applied with the rope along the flat steel plate. Fixing to is easy.

  The bearing plate is a ring-shaped plate made up of six divided ring pieces, and the ring pieces are connected to each other, and each adjacent ring piece that forms a substantially one-sixth region is wound around a rolling roller. If it is designed to be held down by a rope that appears on the ground surface, even if there is a partial weathering difference in one ring-shaped plate, the natural adjustment of the tension will be made in units of approximately one-sixth area. become. Since the function of the ring-shaped plate as a pressure bearing plate behaves finely with respect to the surface layer, it is possible to reduce as much as possible that the pressing force varies greatly for each ring piece.

  According to the invention of claim 5, even if there is no action by the tension holder, the effect obtained by the other claim 1 is exhibited. As a result of this, the rope remains connected to the ring-shaped plate against the surface collapse when the landslide begins to occur, so that a sudden total landslide can be delayed.

The perspective view which showed the connection by the ring-shaped plate of triangular arrangement | positioning in the landslide protection work which concerns on this invention, and its rope. Structure explanatory drawing of a ring-shaped plate and a roller support metal fitting. A plan view of landslide protection laying. Ground plate installation diagram of ring-shaped plate and roller support bracket. Explanatory drawing of a structure and a pressure share of a triangular loop. Explanatory drawing of behavior when using a steel bar as a tension holder. A plan view of a landslide protection work drawn by separating triangular loops. Explanatory drawing of the example of a formation procedure of a triangular loop. Explanatory drawing of the behavior of the landslide protection work when the surface layer is thin due to weathering or the like. The aspect diagram by a corrugated steel bar. Explanatory drawing of the elongation change of a bow-shaped flat steel plate and the rope along it. The top view of an example of an arcuate flat steel plate, the bottom view, and the structural example of the corrugated flat steel plate of the state which formed the main body with three flat steel plates. A ring-shaped plate with a six-segment ring piece and its behavior diagram. The perspective view containing the partial fracture | rupture of a ring-shaped plate with a six division | segmentation ring piece. A prior art example in which a cup-shaped bearing plate is used. Sectional drawing in the slope which has arrange | positioned the cup-shaped bearing plate.

  Below, the landslide protection work concerning the present invention is explained in detail based on a drawing showing the embodiment. FIG. 3 shows a landslide protective work 1 in which tension is applied to a rope 3 that craws on the ground surface by a rock bolt anchor 2, and a plurality of bearing plates 4 arranged on the ground surface of the slope are pressed by the rope to suppress loosening of the surface layer. FIG. As shown in FIG. 4, the rock bolt anchor 2 is driven substantially at the center of a recess 5 having a recessed ground surface, and the rope 3 as a tension maintaining material to which a predetermined tension is applied is a bottom of the recess. As will be described later, it is hung on a rolling roller 6 installed in the above, and has a shortened triangular shape as shown in the center of FIG.

  The main components in this landslide protection work are as follows. Referring to FIGS. 1 and 2, a ring-shaped plate 4 forming a bearing plate, a roller support bracket 7 fixed to the top of the lock bolt anchor 2, and the roller Rolling roller 6 attached to the support metal, rope 3 wound around the rotating roller in the opposite position in the triangle, turnbuckle 8 connecting the rope ends and applying tension, and recovering the rope tension Therefore, the tension holder 9 generates elastic force in the direction of constantly increasing the degree of curvature in the middle of the rope. Then, one unit 10 is formed by the ring-shaped plate 4 arranged at the apex of the triangle and the rope 3 laid in the triangular shape, and the ring-shaped plate at a common position is co-pressed in cooperation with the adjacent unit. To be able to.

  Details in detail. The bearing plate is a ring-shaped plate 4 as can be understood from FIG. A roller support fitting 7 shown in FIG. 2 (b) is fixed to the top of the lock bolt anchor 2 struck on the lower part of the substantially inverted conical depression 5 formed in the natural ground at the substantially central portion of the ring-shaped plate. As shown in FIG. 2 (c), the roller support fitting includes three rotating rollers 6 spaced approximately 120 degrees around the lock bolt anchor 2 and has a substantially inverted conical surface that forms a recess in the shaft 6a. It is arranged and supported so as to be in the direction of the approximate normal 5c of 5a. Thus, since the bearing plate is a hollow disc, it is lighter than any of the bearing plates mentioned in the section of the background art, and the transportation labor in a mountain with poor scaffolding can be greatly reduced. Needless to say, steel consumption is also reduced. Note that the outer peripheral edge and the inner peripheral edge of the ring-shaped plate 4 are bent toward the ground, the outer peripheral edge 4 a functions as a spike, and the inner peripheral edge 4 b protects the shoulder 5 b of the recess 5.

  As shown in FIG. 5A, among the three turning rollers 6 inside each ring-shaped plate at the position corresponding to the apex of the triangle, each one of the turning rollers 6A located at the opposite position in the triangle. A single rope 3 that is wound around and follows the shortest path is arranged in a triangular shape. Both ends of the rope are connected by a turnbuckle 8 on the ground surface in the middle position between the two ring-shaped plates 4, and approximately one third of the region at the opposite position of each ring-shaped plate by one rope 3 (FIG. ) A triangular loop is formed to hold a portion occupying the region S of the ring-shaped plate 4 in the shadowed region S, the region T with a dot, and the region S of the region U given a vertical line). .

  In FIG. 5 (a), a tension retainer that constantly generates elasticity in a direction in which the degree of curvature is increased in order to recover the rope tension by elastically changing the degree of curvature on the side where the turnbuckle 8 does not exist. 9 is interposed. This is bent into a bow shape that generates a resilient force in a direction that always reduces the chord length, and is formed with lashing portions 9a that prevent the rope 3 from separating along the bow ends. In this example, an intermediate portion of the rope 3 is wound, and a hook for preventing the rope 3 from coming off is provided as a lashing portion. The tension holder 9 is a single steel bar 9A as shown in FIG. 6A, and the hook is formed by bending the end of the steel bar to lock the rope 3 wound around the steel bar. Has been.

  The behavior of the tension retainer 9 will be described in detail later. A unit 10 is constituted by the turn buckle 8, one ring-shaped plate 4 and the triangularly laid rope 3, as shown in FIG. A triangular loop is formed. Actually, it is laid in the work area as shown in FIG. 3. However, if this unit is easily seen, the units 10 are sequentially arranged independently as shown in FIG. 7 which is a virtual diagram. In some parts around the work area, two ring-shaped plates 4 may be included as in the unit indicated by a two-dot chain line. Incidentally, although not shown in FIG. 3 and FIG. 7, it is sufficient to secure the entire landslide protective work by arranging a load support device of Design Registration No. 1383811 on the periphery.

  As shown in FIG. 2 (a), a roller support bracket 7 is fixed to the top of the lock bolt anchor 2 struck at the center of the substantially inverted conical recess, and the roller support bracket is surrounded by the periphery of the lock bolt anchor 2. Thus, the three rolling rollers 6 having an interval of approximately 120 degrees are supported, so that each of the rolling rollers has very little tension attenuation, and the rope winding with reduced friction is realized. The operation of applying tension to the rope 3 becomes less burdensome, and the maintenance performance of the predetermined tension is improved. Since the rolling rollers 6 are arranged at intervals of about 120 degrees, even if a difference occurs to the extent that each roller pulls the rope 3, the rope 3 wound around the other rollers exerts the pressing action of the ring-shaped plate. It can be complemented, and a stable ground-holding action is demonstrated.

  Then, as described above, in the landslide protection work 1, the units 10 are sequentially connected to the ring-shaped plate 4 of the adjacent unit, that is, based on the arrangement of FIG. Done. This is because a large number of units arranged on the ground surface can be laid so as to co-push the ring-shaped plate 4 in cooperation with adjacent units. A triangle according to the terrain is given each time, and it is easy to adjust the angle with the adjacent unit, and the laying is flexible.

  In the landslide protective work having such a configuration, the ring-shaped plate 4 is drastically reduced in weight as compared with the disk-shaped bearing plate and the cup-shaped bearing plate described in the background section. At the same time, the formation of the depression 5 at the substantially central portion on the inside makes it possible to raise the rope 3 from the bottom of the depression and improve the natural mountain pressing function by the ring-shaped plate 4 by the rope tension. The pressing effect exceeds a disk and can be exhibited as much as a cup-shaped support plate.

  With reference to FIG. 4, first, a natural ground is dug in the position corresponding to the ring-shaped plate 4 arrange | positioned in a construction area, and the predetermined number of hollows 5 are made. At the center, a rock bolt anchor 2 that penetrates the slip layer and reaches the stable layer is placed, and cement paste or mortar is injected and fixed. The roller support metal fitting 7 having three petals is fitted into the bottom of the anchor although it is the top of the anchor, and fixed with a lock nut 11 or the like. This comprises a roller support upper plate 7a, a roller support lower plate 7b and a rotating roller 6 shown in FIG. 2 (d). The roller support upper plate and the roller support lower plate are substantially similar. The former is slightly smaller than the latter (see also FIG. 2 (b)). The rolling roller 6 is supported between the opposing petal pieces, and is supported by a shaft 6a extending in a direction of a substantially normal line 5c with respect to a substantially inverted conical surface 5a formed by a depression grasped from FIG. The rope 3 can be rotated freely so that the rope 3 can be smoothly displaced in the pulling direction.

  Since the roller support fitting 7 is assembled in advance, it can be attached to the lock bolt anchor 2 very easily. And the ring-shaped plate 4 is arrange | positioned so that it may extend to the shoulder part 5b of the hollow 5, or its outer periphery like FIG. The rope 3 is wound around each of the rolling rollers 6, and the procedure is as shown in FIG. 8 (a). The rope 3 is passed through the roller support fitting 7 in one ring-shaped plate 4A, and a tension holding tool is provided on each side. Tangle 9. As shown in FIG. 8B, the rope 3 is passed through the roller support fitting 7 in the remaining ring-shaped plates 4B and 4C. In this way, the tension retainer 9 is interposed at portions corresponding to the two sides of the rope triangle. Finally, the rope ends are connected by the turnbuckle 8 and a state as shown in FIG.

  The turnbuckle 8 is rotated strongly to draw the rope 3 and apply tension. The rope 3 moves smoothly by the rolling roller 6 and does not come into contact with other ropes 3, so that the friction does not increase and the tightening operation by the turnbuckle is less burdensome. The steel rod 9A of the tension retainer 9 is pulled to reduce its curvature and increase the chord length. Since the degree of curvature is strong in the free state, the steel rod with the reduced degree of curvature generates a resilient force for restoration to balance the tension acting on the rope 3. This gradually applies tension to the triangular rope. Since the tension acting on the rope 3 can be known from the change in the length of the chord length of the steel rod, the operator nearby can assist while knowing some of the tension.

  When the triangular units 10 are laid one after another so as to share the ring-shaped plate 4, the landslide protective work 1 spreads in the work area as shown in FIG. 3. When attention is paid to the three ring-shaped plates 4, as shown in FIG. 1, triangular ropes 3 </ b> A, 3 </ b> B, 3 </ b> C are suspended on one ring-shaped plate 4. However, since the ropes 3 are wound around the respective rolling rollers 6, there is no mutual interference, and tension adjustment is less burdensome. When the laying is completed in this way, the slip layer upper portion 12 near the surface layer of the natural ground is not complete as shown in FIG. In the lower slip layer lower part 14, the whole area is placed in a state in which a pressing force is applied, and the collapse of the natural ground is effectively protected before the landslide occurs (see also FIG. 9 (a)).

  When the surface layer is weathered over the years after laying and the mountain surface is thinned, the surface layer sinks from the state of FIG. 9A to (b). Even if the decrease is local as in the central part of the figure, the tension of the rope 3 located in the part 1a is relaxed as in the vicinity of the ring-shaped plate 4M in FIG. However, since the tension retainer 9 has a resilient force to overcome the weakened tension, as shown in FIG. 9 (e), the string length is reduced by a slack amount ΔL and the string height is increased by ΔH, and the degree of curvature is reduced. Increase. In the landslide protection work, as shown in FIG. 9 (d), the rope 3 is drawn, and the tension is restored and the slack is removed. Although the tension is slightly reduced, since the rope 3 is not left in a free state, the pressing action of the natural ground is still maintained.

  Although the progress of weathering is unavoidable, the tension adjustment is automatically performed for each unit of the triangle, so that it does not affect the rope in the part that is not weathered. Therefore, the initial pressing force is maintained in the portion where there is no weathering. Since the supporting plate is a ring-shaped plate, each triangular rope bears one third, and the supporting pressure acting at an interval of about 120 degrees does not drop significantly at that portion. In the early stage of landslide occurrence, the ring plate connected via the roller support bracket acts to suppress the slip, while the tension retainer behaves like a rope when it encounters an excessive slip. Can be prevented from peeling off from the rock bolt anchor or the ring-shaped plate and suddenly collapsing the surface layer.

  If it is possible to detect the displacement of any of the ring-shaped plates separately, on the slope near the residential land, you know the slight displacement, and the landslide protection worker earns time until it collapses You can evacuate in between. As can be seen from the above description, each winding roller realizes the rope winding with no tension attenuation and reduced friction, reduces the tension applying operation to the rope, and improves the predetermined tension maintaining performance. Since the rolling rollers are arranged at intervals of approximately 120 degrees, even if there is a difference in the degree to which each roller pulls the rope, the rope wound around the other roller complements the pressing action of the ring-shaped plate. It is possible to maintain a stable ground-holding action. The rope is arranged in a triangular shape so as to follow the shortest path by winding a single rope around the roller for rotation, so the rope can be shortened, and the tension applied by the turnbuckle is extremely easy and at a predetermined value. Easy to keep.

  Since the formation of a triangular loop can expand the work area in units of loops, the work area can be easily expanded later. Since the rope does not overlap between the ring-shaped plates in the triangular loop, that is, since there is no portion to be double suspended, the rope is not excessively used.

  Since the tension retainer is interposed in the middle part of the rope, even if the surface layer is weathered and the mountain surface is thinned, the looseness of the rope caused thereby is absorbed by the tension retainer and the tension of the rope is maintained. Even if the landslide started to be maintained and the landslide began to press, the rope was kept in tension and the landslide was suppressed, and the rock bolt anchor was fixed to the stable layer of the hill. As long as it is done, the collapse of the surface layer is as small as possible and can be delayed. In addition, even if there is a local landslide, it cannot be overlooked that a synergistic effect that complements the anti-slip action is exhibited. This is because the triangular loop is one unit, and many units are laid on the ground surface so as to co-push one ring plate between adjacent units.

  The tension holder described above is bent into an arc shape that generates a resilient force in a direction that always reduces the chord length, but generates a resilient force in a direction that always reduces the wavelength, as shown in FIG. A steel rod 9B bent into a corrugated shape can also be used. As can be seen from a comparison of FIGS. 10A and 10B, it is needless to say that the larger the waveform, the larger the capacity to absorb the looseness of the rope, and the larger the amount of rope supply.

  In FIG. 11, the tension retainer 9 is a flat steel plate 9C. The flat steel plate is bent and itself has a configuration as shown in FIGS. The former is a front view and the latter is a bottom view. The lashing portion is a U bolt 15 that presses a rope placed on the back side of the flat steel plate. If it does in this way, since it becomes a U bolt hanging in the state where the rope was along the back side of a flat steel plate, fixation to a flat steel plate becomes easy. Observing and confirming the deformation of the flat steel plate at the time when the tension is applied is obvious at a glance, so that the lashing operation and the tension applying operation can be accelerated. At the same time, the tension setting can be tightened. In addition, as shown in FIG. 12C, when the bending plate 9C is combined, the absorption capacity can be increased as in the case of FIG. 10, and the amount of rope supply can be increased.

  FIG. 13 (a) shows a ring-shaped plate 4S made of six-divided ring pieces, and the ring pieces are directly or indirectly connected to each other by a plastic belt 16 or the like. As shown in FIG. Each of the ring pieces 4 c adjacent to each other forming a region is pressed by the rope 3 that appears on the ground surface after being wound around the rolling roller 6. Therefore, even if there is a difference in partial underlaying in one ring-shaped plate 4S, as shown in FIG. 13 (b), the rope tension that suppresses the ring piece 4c in units of approximately one-sixth region is naturally set. Will be adjusted. Since the ring-shaped plate is finely supported for each surface layer portion, it is possible to reduce as much as possible a significant difference as compared with the pressing force of other ring-shaped plates.

  The above is an example in which the tension holder 9 is interposed as shown in FIG. However, as shown in FIG. 5B, a triangular rope unit 10A in which the tension retainer 9 is not interposed may be used. In that case, the effect of the tension retainer is not exhibited, but it goes without saying that other effects still occur in the same manner. That is, as a result of the rope remaining connected to the ring-shaped plate against the surface layer collapse when the landslide begins to occur, there is no change in that it is possible to delay a sudden total landslide. Incidentally, the tension maintaining material that can be hung on the turning roller is a rope, but it goes without saying that it may be a wire rope or a plastic rope having excellent weather resistance.

  DESCRIPTION OF SYMBOLS 1 ... Landslide protective work, 2 ... Rock bolt anchor, 3 ... Rope, 3A, 3B, 3C ... Triangle-shaped rope, 4, 4A, 4B, 4C, 4M ... Ring-shaped plate (supporting plate), 4S ... Six division type ring -Shaped plate, 4c ... ring piece, 5 ... depression, 5a ... substantially inverted conical surface, 5c ... normal, 6, 6A ... rolling roller, 6a ... shaft, 7 ... roller support bracket, 8 ... turn buckle, 9 ... tension 9a, 9B ... steel rod, 9C ... flat steel plate (curved plate), 10, 10A ... one unit, 15 ... U bolt, S ... area.

Claims (5)

Tension is applied to the rope that hits the ground surface by a lock bolt anchor placed in the approximate center of the depression, and the plurality of bearing plates arranged on the ground surface of the slope are pressed by the rope to suppress loosening of the surface layer. In landslide protection work,
The bearing plate is a ring-shaped plate, and a roller support bracket is fixed to the top of the lock bolt anchor hitting the lower part of the substantially inverted conical recess formed in the ground at a substantially central portion of the ring-shaped plate. Three rolling rollers having a spacing of about 120 degrees around the lock bolt anchor are supported on the support bracket, with their axes arranged so as to be in a direction substantially normal to the substantially inverted conical surface,
One rope wound around each one of the three turning rollers located in the triangle among the three turning rollers inside the ring-shaped plate at the position corresponding to the apex of the triangle is triangular. The two ends of the rope are connected by turnbuckles at the ground surface at the middle position between the two ring-shaped plates, and a portion occupying approximately one-third of the region at the opposite position of each of the ring-shaped plates by one rope. A triangular loop is formed,
On the side where the turnbuckle does not exist, a tension holding device that generates elastic force in a direction to constantly increase the degree of curvature in order to recover the rope tension by elastically changing the degree of curvature is accompanied by a rope tying portion. Intervened,
The triangular loop and the ring-shaped plate arranged at one of its apexes are set as one unit, and a large number of units arranged on the ground surface are laid so as to co-press the ring-shaped plate in cooperation with adjacent units. Landslide protector characterized by   The said tension holding tool is a steel bar, and the said securing part is a hook formed by bending the end of the steel bar to lock a rope wound around the steel bar. Landslide protection work.   The landslide protector according to claim 1, wherein the tension holder is a flat steel plate, and the tying portion is a U bolt that presses a rope along the flat steel plate.   The bearing plate has a ring-shaped plate formed of six divided ring pieces, the ring pieces are connected to each other, and each of the adjacent ring pieces forming the approximately one-third region is wound around the turning roller. The landslide protection work according to any one of claims 1 to 3, wherein the landslide protection work is pressed by a rope that appears on the ground surface after being turned. Tension is applied to the rope that hits the ground surface by a lock bolt anchor placed in the approximate center of the depression, and the plurality of bearing plates arranged on the ground surface of the slope are pressed by the rope to suppress loosening of the surface layer. In landslide protection work,
The bearing plate is a ring-shaped plate, and a roller support bracket is fixed to the top of the lock bolt anchor hitting the lower part of the substantially inverted conical recess formed in the ground at a substantially central portion of the ring-shaped plate. Three rolling rollers having a spacing of about 120 degrees around the lock bolt anchor are supported on the support bracket, with their axes arranged so as to be in a direction substantially normal to the substantially inverted conical surface,
One rope wound around each one of the three turning rollers located in the triangle among the three turning rollers inside the ring-shaped plate at the position corresponding to the apex of the triangle is triangular. The two ends of the rope are connected by turnbuckles at the ground surface at the middle position between the two ring-shaped plates, and a portion occupying approximately one-third of the region at the opposite position of each of the ring-shaped plates by one rope. A triangular loop is formed,
The triangular loop and the ring-shaped plate arranged at one of its apexes are set as one unit, and a large number of units arranged on the ground surface are laid so as to co-press the ring-shaped plate in cooperation with adjacent units. Landslide protector characterized by