JPH11222867A - Natural-slope stabilizing construction method and bearing member therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a natural-slope stabilizing construction method capable of effectively stabilizing a natural slope while preferably maintaining the natural slope. SOLUTION: A tensile member 12 such as an anchor rod is penetrated into a ground on a natural slope 11 first while the front end section of the tensile member 12 is fixed onto a hard foundation ground 13. A downward conical body-shaped member 15 is arranged onto the upper section of the tensile member 12, and the conical body- shaped member 15 is pushed in by any means from a ground surface, and buried into the ground. A bearing member 14 is disposed to the ground projecting section of the tensile member 12, a tensile force is given to the tensile member 12 bearing force to a stratum between the conical body-shaped member 15 and the hard foundation ground 13 is worked to the bearing member 14 receiving the reaction of the tensile force and the conical body-shaped member 15 on the underside of the bearing member 14 and the natural slope 11 of interest is stabilized by the bearing effect. Accordingly, the bearing effect in the bearing member 14 is increased by the working of the conical body-shaped member 15, and a slope stabilizing effect is improved. Since the natural slope is not excavated, the natural slope is maintained preferably.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a natural slope stabilization method for stabilizing a natural slope, and a bearing member used in the method.

[0002]

2. Description of the Related Art Conventionally, as a slope stabilization method for stabilizing a slope having a risk of landslide or collapse, as shown in FIG. The tip is fixed to the hard foundation ground 3, and a supporting member 4 is disposed on the above-ground protruding portion of the pulling member 3. There is known a slope stabilization method for stabilizing the slope 1 by pressing the slope.

In this case, the bearing member 4 receiving the reaction force of the tension acts on the stratum between the hard foundation layer 3 and the stratum to stabilize the slope. Is not only applied directly below the bearing member 4 but is dispersed in a region that is substantially conical from the bearing member 4. Therefore, the spacing between the bearing members 4 should be set appropriately. Thus, the entire slope can be stabilized.

[0004]

If the above-mentioned slope stabilization method is applied to a natural slope having a soft surface layer, dispersion of bearing pressure is small, and the slope stabilizing effect is reduced. Therefore, the bottom area of the supporting member 4 is increased, and a large number of supporting members 4 are provided.
The denser arrangement of the slopes naturally increases the slope stabilizing effect. However, this requires cutting down trees on natural slopes and performing construction, which may lead to destruction of the natural environment. Therefore, it is desirable to improve the bearing effect (effect of restraining the stratum by the bearing force) in each bearing member 4 and to stabilize the slope with the highest possible efficiency. In addition, it is desirable to avoid excavation on natural slopes and to make use of the characteristics of natural slopes with soft surface layers when installing bearing members.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to improve the bearing effect of individual bearing members, to avoid excavation of a slope, and to effectively utilize the characteristics of a natural slope. It is an object of the present invention to provide a natural slope stabilization method preferable for environmental preservation of a natural slope and a bearing member used in this method.

[0006]

The natural slope stabilization method of the present invention for solving the above-mentioned problems includes a method of penetrating a tension member into the ground on a natural slope and fixing a tip end thereof to a hard foundation ground, In the natural slope stabilization method of stabilizing the natural slope, a supporting member is arranged on the above-ground protruding portion, and the surface of the ground is pressed by the supporting member receiving a reaction force of the tension applied to the pulling member. A downwardly facing cone-shaped member is disposed on the lower surface side of the supporting member, and the cone-shaped member is pushed from the surface of the ground and buried in the ground.

According to a second aspect, in the natural slope stabilization method according to the first aspect, a screw is formed near an upper end of the tension member,
A female screw portion is integrally provided at a central portion of the cone-shaped member, and the female screw portion of the cone-shaped member is screwed to the screw portion of the pull member, and the screw is driven by a screw thrust when the cone-shaped member is rotated. The body member is buried in the ground.

According to a third aspect of the present invention, in the natural slope stabilization method of the first aspect, when a tension is applied to the pulling member, the cone-shaped member is buried in the ground by the tension.

According to a fourth aspect, in the natural slope stabilization method of the first aspect, the outer peripheral surface of the conical member has a concave shape.

According to a fifth aspect of the present invention, in the natural slope stabilization method of the first aspect, the cone-shaped member is integrally provided as a part of the bearing member.

According to a sixth aspect of the present invention, a natural slope stabilization method is provided in which the natural slope stabilization method according to any one of the first to fifth aspects is applied to a plurality of locations on the natural slope, and then the supporting members are connected to each other with a wire rope. It is characterized by.

A seventh aspect of the present invention is a bearing member used in the natural slope stabilizing method according to the fifth aspect, wherein a hollow hole made of steel has a hole formed in the center of the bottom plate and a center hole formed with a tension member insertion hole. The body is inserted, the outer periphery at the intermediate height position is brought into contact with the periphery of the hole and fixed by welding, and a reinforcing rib is fixed by welding between the bottom plate and the outer surface above the bottom plate of the hollow cone. .

[0013]

FIG. 1 is a block diagram showing an embodiment of the present invention.
A description will be given with reference to the embodiment shown in FIGS. FIG.
(A) to (c) show an embodiment of the natural slope stabilization method of the present invention. First, as shown in FIG.
In 1, a tension member 12 such as an anchor rod is penetrated into the ground, and its tip is fixed to a hard foundation 13. Next, as shown in FIG. 1 (b), a downwardly facing cone-shaped member 15 is disposed above the pulling member 12,
The conical member 15 is pushed from the surface of the ground by some means and is buried in the ground as shown in the figure. Then, FIG.
As shown in (c), a supporting member 14 is disposed on the above-ground protruding portion of the pulling member 12, applies tension to the pulling member 12, and receives the reaction force of the tension.
And the pyramidal member 15 on the lower surface
And a bearing force acting on the stratum between them, and the natural slope 11 is stabilized by the bearing effect.

After the above operation is performed at a number of places on the natural slope, the supporting members 14 are tightly connected to each other with a wire rope 17 as shown in FIG. Thereby, the supporting effect of each supporting member 14 increases.

In the natural slope stabilization method described above, since the cone-shaped member 15 is buried by being pushed from the surface of the ground, a pressure bulb (compacted by a compaction) is provided below the supporting member 14 by embedding the cone-shaped member 15. Soil mass) is formed, and these pressure bulbs effectively transmit bearing pressure into the stratum,
The bearing effect of the bearing member 14 increases. Also,
Compared with the conventional method in which only the flat bottom surface of the bearing member contacts the stratum, the bearing effect is also increased in that the contact area with the stratum is increased as a whole. In addition, the cone-shaped member 15
In comparison with the conventional method in which the ground surface is pressed only by the flat bottom surface of the supporting member, the direction of action of the pressure by the cone-shaped member 15 has an angle as shown by an arrow, and the supporting pressure is widely dispersed. Therefore, also in this respect, the supporting effect of the supporting member 14 is increased. As described above, since the bearing effect of the individual bearing members 14 is increased, the spacing between the bearing members 14 to be arranged can be slightly increased as compared with the case of the conventional method. It is possible to reduce the bottom area of even a little, which is good for preserving natural slopes.

Further, since the cone-shaped member 15 is pushed from the ground surface and buried in the ground, and does not excavate the ground surface,
This is also good for natural slope maintenance. That is, the surface soil layer of the natural slope is usually soft soil on which litter and its decay are deposited, is rich in nutrients, and has a well-developed root system. For this reason, it has a high rainwater penetration capacity and a high surface sediment storage capacity, which is effective for preventing surface collapse of slopes, and is also effective in flood control and drought mitigation. Excavating even a small amount of such natural slopes will drain nutrients from the natural slopes and destroy the root system, impairing the above-mentioned rainwater infiltration capacity and surface sediment storage capacity, as well as damaging the ecosystem. . However, as described above, since no excavation is performed in the method of the present invention, such a problem does not occur, and it is particularly preferable from the viewpoint of natural slope maintenance.
When the bearing member 14 has a reinforcing rib on a bottom plate as will be described in detail with reference to FIGS. 2 to 4 and the like described below, the vicinity of the bottom plate of the bearing member 14 together with the conical member 15 is also provided. When buried, the exposed portion of the ground surface is reduced, which is preferable as a natural slope. Even in this case, the reinforcing ribs and the connected wire ropes are exposed on the surface of the ground, and the movement of the earth and sand on the natural slope surface eroded by rainfall or the like can be stopped. In FIG. 1C, reference numeral 16 denotes sediment.

FIGS. 2, 3 and 4 show more specific examples of the natural slope stabilization method described above. The tension member 12 in this embodiment is an anchor rod having a threaded portion 12a formed on the upper portion. The supporting member 24 is made of a steel plate, and has a rectangular bottom plate 21 having a pulling member insertion hole 21a at the center thereof, and is vertically fixed to the bottom plate 21 by welding to the pulling member insertion hole 21a of the bottom plate 21. Cylinder 2
2 and a reinforcing rib 23 vertically welded and fixed to the outer periphery of the cylindrical body 22 and the upper surface of the bottom plate 21. The reinforcing rib 23 has a cutout 23a through which the wire rope 17 connecting the supporting members 24 is passed. Further, the cone-shaped member 25 is shown in FIGS.
As shown in the figure, the main body is a hollow cone formed by welding and joining a steel plate having a predetermined shape into a hollow cone, or a hollow cone made of cast iron or the like. An insertion hole 25a is provided, and a female screw member 25c is formed at the upper end of a round pipe 25b which is vertically welded and fixed in the vicinity thereof.
Are welded and fixed, and the female screw member 25c is provided with a tool hook hole 25d for rotating operation. The cone-shaped member 25 has a conical surface angle of, for example, about 60 ° so as to be easily pushed into the ground, and the outer diameter of the cut end is made as small as possible. 12 slightly larger than the outside diameter).

In the embodiment shown in FIGS. 2 to 4, the tension member insertion hole 25a of the conical member 25 is passed through the upper part of the tension member 12 penetrating into the ground, and the female screw member 25c is screwed into the upper screw portion 12a. The tool is inserted into the tool hooking hole 25d, the tool is turned, the conical member 25 is turned and moved downward, and the screw is thrust into the ground. Next, the supporting member 24 is disposed on the above-ground protrusion of the pulling member 12, and a nut 27 is screwed into the threaded portion 12a at the upper end of the pulling member 12 with the washer 26 interposed therebetween.
7 is further tightened to apply tension to the tension member 12, and a supporting force is applied to the stratum directly or via the conical member 25 on the bottom surface of the supporting member 24 receiving the reaction force.

FIG. 5 shows another embodiment of the conical member. The conical member 25 'is formed by directly welding and fixing a female screw member 25'c to be screwed to the tension member 12 near the tension member insertion hole on the inner surface of the hollow cone. In this case, a means for rotating the conical member 25 'is separately provided.

Each of the above-mentioned conical members 25, 25 'is a female screw member 25 which is screwed into the screw portion 12a of the pull member 12.
Although it has a structure having c and 25'c, a simple hollow cone without such a female screw member may be used as the cone-shaped member. In this case, as a means for pushing the cone-shaped member, which is a simple hollow cone, into the ground, it is also possible to simply hit the cone-shaped member from above and bury it in the ground. Further, when the tension is applied to the pulling member 12 by turning the nut 27 of the supporting member 24, the cone-shaped member can be embedded in the ground by the tension.

When the cone-shaped member is a simple hollow cone having no female screw member as described above, this is shown in FIG.
It is also possible to form a supporting member with a conical member by welding and fixing integrally to the lower surface of the bottom plate 21 of the supporting member 24. In this case, when embedding the cone-shaped member portion of the supporting member with the cone-shaped member in the ground, when the tension is applied to the pulling member 12 by turning the nut 27, the cone-shaped member is It is good to embed the part.

FIG. 6 shows still another embodiment of the present invention.
In this embodiment, the conical member is a supporting member with a conical member integrated with the supporting member. The supporting member 34 is provided in a hole 31 a formed in the center of the bottom plate 31. A hollow cone 32 made of a steel plate is inserted, and the outer periphery at an intermediate height position thereof is brought into contact with the periphery of the hole 31a and fixed by welding.
The reinforcing ribs 33 are welded and fixed between the hollow cone 32 and the outer surface of the hollow cone 32. The bottom plate 31 in the illustrated example has a generally triangular shape in which corners are cut out. In this case, when a nut is screwed into the screw portion 12a of the pulling member 12 protruding from a washer plate (not shown) placed on the upper end surface of the hollow cone 32 to apply tension to the pulling member 12, the hollow cone The portion of the body 32 below the bottom plate 31, that is, the cone-shaped member portion may be embedded in the ground.

FIG. 7 shows still another embodiment of the conical member. The conical member 45 is formed by making the outer peripheral surface of a hollow conical body concave. This cone-shaped member 45 is
It may be separate from or integral with the supporting member 44. According to the conical member 45 of this embodiment, since the conical outer peripheral surface is concave, the area in contact with the stratum further increases.
The bearing effect of the bearing member 44 is further increased.

In each of the above-described embodiments, the cone-shaped member is described as a cone-shaped member. However, as shown in FIG. 8, a quadrangular pyramid-shaped cone-shaped member 55 may be used. Furthermore, it is not necessary that the cone is a geometrically clear cone, but it is sufficient if the lower side has an outer peripheral surface that gradually narrows. The cone-shaped member does not need to be hollow as long as there is a hole through which the tension member 12 passes.

As the pulling member, a rod (anchor rod or lock bolt) is appropriate from the viewpoint of workability and the like, but a wire rope or the like can also be used.

[0026]

According to the present invention, the conical member is disposed downward on the lower surface side of the supporting member, and the conical member is pushed from the surface of the ground and buried in the ground. Such various effects can be obtained. By burying the cone-shaped member, a pressure bulb is formed below the bearing member, and the bearing pressure is effectively transmitted to the stratum, thereby increasing the bearing effect of the bearing member. The bearing effect also increases in that the contact area between the bearing member and the cone-shaped member as a whole with the formation increases. Since the acting direction of the pressure by the cone-shaped member has an angle and the bearing pressure is widely dispersed, the bearing effect of the bearing member also increases at this point. Since the bearing effect of each bearing member increases, it becomes possible to increase the spacing between the bearing members to be arranged even slightly as compared with the case of the conventional method, or to reduce the bottom area of the bearing member slightly. This is good for preserving natural slopes. The cone-shaped member is pushed into the ground and buried in the ground, and does not excavate the surface. Therefore, it drains nutrients on natural slopes, destroys root systems and ecosystems on natural slopes, and penetrates rainwater into the ground. There is no problem such as impairing the storage capacity of sediment and it is good for natural slope preservation.

According to the second aspect, the female screw member provided on the cone-shaped member is screwed into the threaded portion of the pull member, and the cone-shaped member is grounded by the screw thrust when the cone-shaped member is rotated. Since it is buried inside, the operation of burying the cone-shaped member is simplified.

According to the third aspect, when a tension is applied to the tension member, the cone member is buried in the ground by the tension force. The operation to be performed is simplified.

According to the fourth aspect, since the outer peripheral surface of the conical member has a concave shape, the supporting effect of the supporting member increases.

According to the fifth or seventh aspect, since the conical member is integrated with the supporting member, work and handling are simplified.

According to the sixth aspect, since the plurality of supporting members are connected in tension by the wire rope, the supporting effect of each supporting member is increased.

[Brief description of the drawings]

FIG. 1 is a view showing a natural slope stabilization method according to an embodiment of the present invention in the order of steps (a), (b), and (c).

FIG. 2 is a plan view of a bearing member used in the natural slope stabilization method.

FIG. 3 is an enlarged view of a main part of FIG.

FIGS. 4A and 4B show another embodiment of a cone-shaped member used in the natural slope stabilization method of the present invention, wherein FIG. 4A is a plan view of the cone-shaped member, and FIG. .

FIG. 5 is a cross-sectional view of a conical member used in a natural slope stabilization method according to another embodiment of the present invention, showing still another embodiment.

FIGS. 6A and 6B show still another embodiment of a bearing member used in the natural slope stabilization method of the present invention, wherein FIG. 6A is a plan view and FIG.

FIG. 7 is a front view showing still another embodiment of the supporting member used in the natural slope stabilization method of the present invention.

FIG. 8 is a perspective view showing still another embodiment of the conical member used in the natural slope stabilization method of the present invention.

FIG. 9 is a plan view of a natural slope on which the above-described natural slope stabilization method is applied.

FIG. 10 is a diagram illustrating a conventional natural slope stabilization method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Natural slope 12 Pull member 12a Screw part 14,24,34,44 Support member 15,25,35,45 Conical member 17 Wire rope 21,31 Bottom plate 21a Pull member insertion hole 22 Cylindrical body 23,33 For reinforcement Rib 25a Pull member insertion hole 25b Round pipe 25c, 25'c Female screw member (female screw portion) 31a Hole 32 Hollow cone

Claims (7)

[Claims] Claims: 1. A tension member penetrates into the ground on a natural slope, and a tip of the tension member is fixed to a hard foundation ground.
A natural slope stabilization system in which a supporting member is arranged at a protrusion above the ground of the pulling member, and the ground surface is pressed by the supporting member receiving a reaction force of the tension applied to the pulling member to stabilize the natural slope. A natural slope stabilization method, wherein a downwardly facing cone-shaped member is disposed on a lower surface side of the bearing member, and the cone-shaped member is pushed from the surface of the ground and buried in the ground. 2. A thread is formed near an upper end of the tension member, a female screw portion is integrally provided at a central portion of the cone member, and a female thread portion of the cone member is screwed into a thread portion of the tension member. The natural slope stabilization method according to claim 1, wherein the cone-shaped member is buried in the ground by screw thrust when the cone-shaped member is rotated. 3. The natural slope stabilization method according to claim 1, wherein when applying tension to the tension member, the cone-shaped member is buried in the ground by the tension. 4. The natural slope stabilization method according to claim 1, wherein the outer peripheral surface of the conical member has a concave shape. 5. The natural slope stabilization method according to claim 1, wherein the cone-shaped member is integrally provided as a part of a supporting member. 6. After the natural slope stabilization method according to claim 1 is applied to a plurality of places on the natural slope, the supporting members are connected by tension using a wire rope. Natural slope stabilization method described. 7. A supporting member used in the natural slope stabilization method according to claim 5, wherein a hollow hole made in the center of the bottom plate is inserted with a hollow cone made of steel centered on a hole for inserting a pulling member. A supporting member, wherein an outer periphery at an intermediate height position thereof is brought into contact with a periphery of the hole and fixed by welding, and a reinforcing rib is fixed by welding between the bottom plate and an outer surface of the hollow cone above the bottom plate. .