JP3911286B2 - Natural slope stabilization method and structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a slope stabilization method for protecting a slope such as a natural ground, and more particularly to a natural slope stabilization method and a structure that do not impair a natural landscape.
[0002]
[Prior art]
As a construction method to reinforce natural slopes and cut slopes of natural ground to prevent landslides and collapses and stabilize the slopes, a frame construction method and stability that lay a grid-like concrete frame on the entire slope Ground anchor method and rock bolt method to connect the anchor body reaching the ground and the pressure receiving plate on the slope with a tensile material, or reinforcing material such as rebar is inserted into the slope and the ground is reinforced by the interaction of soil and reinforcement The reinforcing bar insertion method is used. Moreover, such method by applying the further various slope stabilization method has been proposed (for example, (1) KOKOKU 2-13097, (2) JP-B 54-26801, (3) JP-A-9- 111761, (4) Japanese Patent Publication No. 8-14109).
[0003]
Japanese Patent Publication No. 2-13097 of (1) discloses a method in which hollow method frames are arranged in a lattice shape on a slope and fixed with anchors, and inflow holes for allowing mortars to flow into the method frame are provided at predetermined intervals. by forming, that not disclose the method with improved workability.
[0004]
Japanese Patent Publication 54-26801 Patent Publication (2) method which aimed to facilitate the concrete beating work in the field to prevent built, the outflow of the concrete in a mold a fixed reinforcing bar cage in the natural ground slope by the anchor that not disclose.
[0005]
According to Japanese Patent Laid-Open No. 9-111761 (3) , a steel support metal fitting made of a steel short tube and a reinforcing leg plate is provided on a ground plate provided on the slope surface so as to protrude from the slope surface. the by stressing anchorage anchor or rock bolts, that not disclose the method with improved weight and workability member.
[0006]
Japanese Patent Publication No. 8-14109 of (4) conserves trees by combining a deep ground anchor reaching a stable ground and a plurality of reinforcing bar members inserted into the soil above it into a pressure receiving plate. construction method was to stabilize the slope while that not disclose.
[0007]
[Problems to be solved by the invention]
However, in the conventional slope stabilization method, sufficient consideration has not been given to the preservation of the natural landscape of the slope. That is, in the above-mentioned method (1) , such as Japanese Patent Publication No. 2-13097, it is necessary to cut down trees to some extent when installing the method frame in a lattice shape, and the artificial arrangement of concrete Because the frame is exposed on the slope, the natural landscape is damaged and an artificial landscape is created.
[0008]
In place of such a frame that is continuous over the entire slope, Japanese Patent Publication No. 54-26801 and Japanese Patent Application Laid-Open No. 9-111761 of the above (2) and (3) disclose a pressure receiving plate fixed to a tensioned anchor or the like. The ground anchor method, the rock bolt method, or the reinforcing bar insertion method is disclosed in which, for example, the pressure is applied to the inclined surface by using the pressure receiving plate. However, in the conventional ground anchor method including such a technique described in the publication, since the pressure receiving plate on the slope protrudes from the slope and is exposed, the artifacts are scattered and recognized visually. In these cases, the natural landscape was damaged.
[0009]
In addition, in the construction method described in the above Japanese Patent Publication No. 8-14109 (4), the slope is stabilized without cutting the tree, but in this known technique, a pressure receiving plate (capping plate) is also used. The trees are preserved because they are exposed from the slope, but the landscape of the slope is damaged by the pressure plates scattered on the slope.
[0010]
In this way, in the conventional slope stabilization method, the frame and the pressure plate are both installed so as to protrude from the slope, so that the frame and the pressure plate itself are artificial for the surrounding environment that has been greened by trees and the like. It was not good for the landscape because it became a strange foreign body and was not harmonious and uncomfortable.
[0011]
On the other hand, in recent years, in order to prevent landslides and collapse on natural slopes such as natural mountains and stabilize the slope, it is only necessary to protect natural plants such as trees planted on the slope, especially trees, without cutting them as much as possible. Rather, it is required that the man-made structure is not conspicuous and the landscape of the entire area is preserved by reinforcing and stabilizing it without damaging the natural scenery of the slope. Even in such cases, the slope stabilization reliability is further improved than before, and sufficient measures are taken to prevent the collapse of trees during earthquakes, heavy rains, etc., or the fall of slopes of heavy pressure plates during construction. It is necessary to.
[0012]
In view of the above points, in the prior art increases the reliability of the slope stabilization strive to preserve a sufficient consideration is not a natural landscape, moreover natural slope stabilization method and structure having improved workability and safety an object of the present invention is to provide a.
[0013]
[Means for Solving the Problems]
To achieve the above object, in the present invention, the plurality of positions on the natural slope should conserve landscape, formed by excavating a recess of predetermined depth, within the ground from the recess, the tensile member The head is exposed in the recess, penetrated, the tension material head is inserted, and in each recess, the pressure receiving plate is installed or placed so that almost the whole is immersed in the recess, providing a stabilizing structure to which the self Shikahasu surface stabilizing method and construction method, characterized in that to fix the tension member to the pressure receiving plate through the head.
[0014]
According to this natural slope stabilization method and structure , the pressure receiving plate installed on the slope is immersed in a recess provided on the natural slope, and its upper surface does not protrude from the natural slope and becomes inconspicuous. On the other hand, artificial discomfort does not occur, the slope is stabilized, trees are preserved, and the landscape of the area is preserved.
[0015]
In addition, since the pressure receiving plate is immersed in the recess of the slope, the upper side surface of the pressure receiving plate receives the ground on the upper side of the slope to suppress its slipping and collapse, and the lower side surface of the pressure receiving plate is below the recess. Since it is received in contact with the side inner wall surface, the pressure receiving plate is prevented from slipping down on the slope during construction or the like.
[0016]
That is, the pressure receiving plate immersed in the recess has the original function that the bottom surface transmits the tension force of the tensile material to the ground side or strengthens the ground by its own weight, and the upper and lower sides of the pressure receiving plate. Both sides have the functions of stabilizing the surface layer of the ground and improving workability and safety, and the pressure receiving plate does not protrude from the slope and the whole is hidden inside the slope, so there is a sense of incongruity with surrounding natural plants etc. It will not occur and will preserve the natural landscape without damaging it.
[0017]
The present invention can be applied to any of the ground anchor method, the rock bolt method, or the reinforcing bar insertion method, and the tension material fixed to the pressure receiving plate is fixed to the ground to provide an anchor function. Either a structure or a rock bolt structure fixed to the ground over the entire length of the tensile material may be used.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a cross-sectional view of a slope stabilization structure according to an embodiment of the method of the present invention. A ground anchor structure (or rock bolt structure) 4 is formed so as to penetrate into the slope 2 of the natural ground 1 where trees are vegetated. This ground anchor structure (or rock bolt structure) 4 is fixed to a pressure receiving plate 7 made of concrete or the like by inserting a tension material 5 and then filling it with an injection material 6 and tensioning the tension material 5 by applying tension. It has been made.
[0019]
This pressure receiving plate 7 stabilizes the ground by transmitting the tension of the tension member 5 to the ground as described later and pressing the ground, or by applying a deterrent against slipping or collapse of the ground by its own weight. Is. As shown in the figure, the pressure receiving plate 7 reinforces the ground within an angle range of an angle α (usually about 45 degrees) corresponding to the geology, tension, and the like from the peripheral edge to the tension member 5. As a result, the substantially conical ground area becomes a lump of stable and strengthened ground to prevent slipping and collapse.
[0020]
The shape of the pressure receiving plate 7 can be appropriately selected from a rectangular shape, a circular shape, a triangular shape, a rhombus shape, a cross shape, a star shape, and a shape obtained by combining these shapes according to the field conditions. The pressure receiving plate 7 may be formed by on-site application of concrete or mortar as in the examples described later, or may be a product obtained by transporting factory products to the site. Further, not limited to concrete and mortar, resin materials, styrene, fiber-mixed composite materials, and the like can be used, and further, iron plates, shaped steel materials, or combinations thereof can be used.
[0021]
In the case of a ground anchor structure, the tension member 5 is composed of a PC steel material used as a tension material for prestressed concrete such as a PC steel wire, a PC steel strand, a PC steel rod, and a deformed PC steel rod. A plurality of PC steel materials having different lengths may be used together to change the position of the fixing portion with respect to the ground, thereby fixing the optimal position corresponding to the ground to obtain a reliable tension.
[0022]
One or more tension members 5 are provided for one pressure receiving plate 7 to increase the bearing pressure on the ground and widen the range of stabilization. Also, reliability of fixing to the pressure receiving plate and maintenance of tension during long-term use, etc. You may improve the reliability to. In addition, one (or a plurality) ground anchors are provided at the center of the pressure plate and inserted up to the stable ground. Further, a reinforcing material such as a lock bolt or a reinforcing bar is provided at the periphery of the pressure plate, You may insert in the ground to which stability was given by the ground anchor. In this way, in addition to the ground anchor, a structure in which a plurality of reinforcements penetrate further around the ground anchor provides a combined action of the ground strengthening action of the ground anchor method and the ground strengthening action of the lock bolt or reinforcing steel bar insertion method. A single pressure receiving plate enhances the ground stabilization effect over a wide range.
[0023]
The tension fixing method of the tension member 5 is a wedge method in which the tension material head protruding from the pressure receiving plate is tensioned by applying a tensile load with a jack and then fixed to the pressure receiving plate with a wedge, or is screwed into the tension material head. A nut method in which a nut is tightened to apply tension and is fixed to the pressure receiving plate, or a combined method in which a nut is further tightened after fixing with a wedge can be employed.
[0024]
Further, the tensile material 5 in the case of the lock bolt structure uses deformed reinforcing bars, threaded reinforcing bars, hollow full threaded bolts, carbon fiber bolts, FRP lock bolts, etc., and the tensile material can be grounded without giving particularly great tension. It may be fixed on a mountain and the slope may be reinforced with a pressure plate to stabilize the slope.
[0025]
Thus, the pressure receiving plate 7 fixed by the tension member 5 is immersed in the recess 8 formed in the slope 2. That is, the upper surface of the pressure receiving plate 7 is disposed at a position substantially the same as the inclined surface 2 or drawn below it. Thus, by providing the ground anchor structure (or the lock bolt structure) 4 with the pressure receiving plate 7 not being projected on the slope 2 and being immersed inside from the natural ground surface, the pressure receiving plate 7 is hidden in the recess and further ground Hidden by the convex parts and vegetation of the trees. As a result, the slope is stabilized without cutting trees or the like, and the pressure receiving plate, which is an artificial structure, does not lose harmony with the surrounding natural environment, and the natural landscape is preserved.
[0026]
In this case, the upper surface of the pressure receiving plate 7 may or may not be covered with soil. If the upper surface of the pressure plate 7 is covered with soil, the pressure plate can be completely buried and landscape conservation can be reliably achieved, and herbaceous vegetation can be grown on the soil on the pressure plate. Further enhanced.
[0027]
For maintenance or inspection of the pressure receiving plate, the pressure receiving plate itself or the end of the tensile material protruding from the surface of the pressure receiving plate or the oil cap that covers it may be exposed and used as a marker for the embedded position. In this way, instead of exposing the pressure plate itself or its surface member to serve as a mark of the buried position, the same type of unified middle shrub tree around the pressure plate, a sign indicating the altitude, or a sign displaying the tree name Or the like may be used as a mark indicating the pressure receiving plate burying position.
[0028]
By immersing the pressure receiving plate 7 in the recess 8 in this manner, the side surface portion on the upper side of the slope of the pressure receiving plate 7 receives and supports the weight of the ground surface layer portion from the upper side of the slope of the recess 8. Therefore, it becomes a resistance deterrent against landslide and collapse, and the ground strengthening action by the ground anchor structure (or rock bolt structure) 4 itself is assisted, and the effect of stabilizing the slope is further enhanced. In this case, by providing the pressure receiving plate 7 close to the underside of the tree, the ground under the tree is firmly stabilized by the pressure receiving plate, so there is no collapse or landslide during an earthquake or heavy rain. , Tree collapse is prevented. Furthermore, the effect of slope stabilization is further enhanced in combination with the net effect that suppresses the soil collapse of the root system of woody plants.
[0029]
Further, by immersing the pressure receiving plate 7 in the recess 8 in this way, the side surface portion of the pressure receiving plate 7 on the lower side of the inclined surface comes into contact with and is received by the inner wall surface of the recess 8, so that the pressure receiving plate follows the inclined surface. It is held in that position without slipping off. Therefore, especially when installing factory products on the site with a crane or the like, the pressure receiving plate, which is a heavy concrete material, is securely held at a predetermined position on the slope during or after installation, and the position is shifted by slipping down the slope. In this way, workability is improved, workability is improved, and construction safety is improved.
[0030]
The pressure receiving plates 7 installed on the slope may be in an independent state or may be connected by a wire rope or the like. In this case, the connecting wire rope, etc. should be connected to the upper part of the lock bolt, etc. that protrudes from the upper surface of the pressure-receiving plate, and other appropriate positions, and a shallow groove should be dug along the ground surface so as not to damage the surrounding landscape. It is desirable to embed and arrange.
[0031]
Next, the construction procedure for the embodiment of the slope stabilization method according to the present invention will be described. In this example, a rectangular pressure receiving plate is formed in a vertically long shape along the slope. First, as shown in FIG. 2, a rectangular recess 8 corresponding to the pressure plate shape is excavated and formed on the slope 2 of the natural ground 1.
[0032]
Next, as shown in FIG. 3 as an example, a tensile member 5 covered with a sheath 9 for drilling a central portion of the recess 8 to form a ground anchor structure is inserted. In order to securely fix the tension material 5 to the ground, an injection material 6 (grouting) made of cement paste is injected into the hole. A screw is formed on the head 5 a of the tension member 5 and is exposed from the sheath 9. The sheath 9 is made of stainless steel, polyethylene pipe or the like, and the sheath 6 may be filled with an injection material 6a containing antirust oil so that tension can be transmitted to the fixing ground without loss. As described above, various materials can be used as the tension member 5, and in the case of a ground anchor structure, an anchor body may be provided at the fixing portion with respect to the ground at the tip.
[0033]
Next, as shown as an example in FIG. 4, a reinforcing bar frame 10 is installed in the recess 8, and concrete 11 or mortar is poured into the recess 8 as a mold to form the pressure receiving plate 7. FIG. 4 shows a structure using a lock bolt as the tension member 5. Thereafter, a nut 13 is attached to the head 5 a of the tension member 5 protruding from the upper surface of the pressure receiving plate 7 via the square washer 12. Tightening force is applied to the tension member 5 by tightening the nut 13. Thereafter, an oil cap may be put on the tension material head. FIG. 5 is a configuration explanatory view of an upper surface mold used when the pressure receiving plate 7 made of the cast-in-place concrete is formed using the recess 8 as a mold, (A) is a front view, and (B) is a side view. is there. This upper surface formwork 14 has a tensile material insertion hole 15 such as a lock bolt in the center and two concrete injection windows 16a and 16b at the top and bottom. A lid 17 is provided on the inner surface side of the lower window 16b.
[0034]
At the time of use, the rebar frame 10 (FIG. 4) is set in the recess 8, and the upper surface formwork 14 is fixed in a state where the head of the tensile material is passed through the insertion hole 15. In this state, concrete is first poured from the lower window 16b, and then concrete is poured from the upper window 16a to fill the recess 8 with concrete. When the concrete is poured from the upper window 16a, the lid 17 of the lower window 16b is pushed by the concrete and closes naturally. In this way, the pressure receiving plate is formed by in-situ punching using the recess 8 as a mold and further using the upper surface mold 14. Depending on the inclination angle of the slope, concrete may be cast without using the upper surface formwork 14. Further, the concrete injection window may be provided at only one upper portion or three or more depending on the size of the pressure receiving plate.
[0035]
FIG. 6 shows another configuration example of the pressure receiving plate. In this example, two shaped steels 18 are connected by bolts 19 to form a pressure receiving plate 20. It is desirable to hit the concrete 11 on the lower surface side of the shape steel 18 in order to absorb unevenness of the bottom surface of the recess. Other configurations are the same as those in the example of FIG. In addition, the concrete 11 may be hit to the upper surface of the shaped steel 18 and the pressure receiving plate may be made of concrete in the same manner as in the example of FIG. 4, and the shaped steel 18 may have the same action as a reinforcing steel bar.
[0036]
【The invention's effect】
As described above, in the present invention, the pressure receiving plate installed on the slope is immersed in a recess provided on the natural slope, and its upper surface does not protrude from the natural slope and becomes inconspicuous. Artificial discomfort does not occur, the slope is stabilized, trees are preserved, and the landscape of the area is preserved. Moreover, since it does not protrude from the natural slope, it is safe without tripping when a person walks.
[0037]
In addition, since the pressure plate is embedded in the recess of the natural slope, the upper side surface of the pressure plate receives the ground above the slope and prevents its slipping and collapsing, increasing the reliability of stability of the slope. Since the lower side surface is received by being brought into contact with the lower inner wall surface of the recess, the pressure receiving plate is prevented from slipping down on the slope during construction or the like, and the workability is improved and the safety is enhanced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a slope stabilization structure according to the present invention.
FIGS. 2A and 2B are a front view and a cross-sectional view, respectively, for explaining an initial procedure of a slope stabilization method according to the present invention.
FIGS. 3A and 3B are a front view and a cross-sectional view illustrating a procedure following the procedure of FIG.
4A and 4B are a front view and a cross-sectional view illustrating a procedure following the procedure of FIG.
FIGS. 5A and 5B are a front view and a cross-sectional view, respectively, of an upper surface formwork used in the concrete placing shown in FIG. 4;
6A and 6B are a front view and a cross-sectional view, respectively, of a pressure receiving plate according to another embodiment of the present invention.
[Explanation of symbols]
1: Ground, 2: Slope, 4: Ground anchor structure, 5: Tensile material, 6: Injection material, 7: Pressure plate, 8: Recess, 9: Sheath, 10: Rebar frame, 11: Concrete, 12: Square washer, 13: Nut, 14: Upper formwork, 15: Insertion hole, 16a, 16b: Window, 17: Lid, 18: Shape steel, 19: Bolt, 20: Pressure plate

Claims (3)

A plurality of locations on the natural slope should conserve landscape, formed by excavating a recess of predetermined depth, within the ground from the recess, the tension member, to expose the head in the recess The pressure receiving plate is installed or placed so that the entire pressure member is inserted into the recess by penetrating through the tension material head, and the pressure receiving plate is inserted through the head. self Shikahasu surface stabilizing method, characterized in that to fix the. Self Shikahasu surface stabilizing method according to claim 1, characterized in that covering the pressure receiving plate top with soil. In fixed slope stabilizing structure tension member to the pressure receiving plate provided separately at a plurality of positions on the natural slope, the pressure receiving plate is substantially entirely be retracted into the recess drilled formed on a natural slope, the upper surface the self Shikahasu surface stabilizing structure, characterized in that in substantially flush or below the position and nature slope.

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