JP2000073374A - Slope stabilizing method and independent slope bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the uniform bearing capacity irrespective of the presence/ absence of the degree of execution of slopes or boulder stones in a ground anchor method and a lock bolt method to stabilize the slopes, to miniaturize a bearing device of ground anchors, to green approximately the whole slopes, to reduce the execution cost due to weight reduction, and to reinforce and to prevent collapse of the slopes. SOLUTION: In a slope slip preventive method in which a slip on the slope (an arc slip, a compound slip, etc.), is resisted by ground anchors (a ground anchor, a lock bolt, etc.), the ground anchors are studded on the slope, and a slope independent bearing device 1 comprising a plurality of bearing piles 2 (excavated holes, steel bar anchors 5, reinforcing bars 7, grout 8) and bearing plates 3 is arranged at the position of execution of the ground anchors A, and the anchoring force of the ground anchors A is transmitted underground through the bearing plates 3 and the bearing piles 2 to execute the vegetation between the devices 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slope stabilization method using a ground anchor method or a rock bolt method for preventing a landslide or a collapse of a slope, and a slope independent pressure receiving device used for the method. .

[0002]

2. Description of the Related Art As a slope stabilization method, a slope slip prevention (slope suppression) method using a ground anchor or a lock bolt is generally used. For the reaction force of the anchor force, it is necessary to provide a bearing surface corresponding to the bearing capacity of the slope surface. Conventionally, for example, a PC (precast) frame method is adopted and a precast concrete slab is used as a bearing device. Used as

[0003]

However, the bearing device used in the conventional ground anchor method and the rock bolt method has a bearing surface that matches the supporting force of the slope, considering the slope as a surface. There are the following problems from the viewpoint of stabilizing the surface. (1) Since the cut slope is constructed with a machine such as a backhoe,
The construction accuracy is poor, the slope surface has irregularities, and it cannot be evenly loaded on the concrete bearing plate. (2) When boulders are scattered on the cut slope, the supporting point of the precast concrete product is cracked due to breakage and deformation due to point support. (3) If the cut slope does not have the supporting capacity corresponding to the design anchor force, it is necessary to increase the bearing area to match the supporting force of the cut slope. (4) The bearing surface of the cut slope that receives the design anchor force needs to have a larger bearing area as the anchor force increases, and most of the slope surface is covered with concrete and greened. The area to do is drastically reduced. In addition, even when the in-situ frame method is used, vegetation is possible inside the frame,
It is about 78-69%. (5) For precast concrete products, 1.3 to 5.1
The construction is large because of the weight of t and the need for a large lifting machine.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a ground anchor method and a rock bolt method for stabilizing a slope.
Uniform bearing capacity can be obtained without being affected by poor slope construction and the presence or absence of boulders, and the pressure receiving devices for ground anchors can be reduced in size, and almost the entire slope is green, almost green. It is an object of the present invention to provide a slope stabilization method and a slope independent pressure receiving device capable of reducing the construction cost by reducing the weight, further reinforcing the slope and preventing collapse. .

[0005]

SUMMARY OF THE INVENTION The slope stabilization method of the present invention is a slope which resists a slip on the slope (such as an arc slip or a complex slip) with ground anchors (ground anchors, rock bolts, etc.). In the anti-slip method, after constructing the ground anchors so as to be scattered on the slope, at the construction position of this ground anchor, a slope independent pressure receiving device consisting of a plurality of support piles and pressure receiving members is arranged, The anchor force of the ground anchors is transmitted to the ground via the pressure receiving member and the support pile (claim 1).
In the slope stabilization method, vegetation (grass, trees, etc.) is performed between the slope independent pressure receiving devices (claim 2).

The slope independent pressure receiving device of the present invention is provided at a construction position of ground anchors (ground anchors, rock bolts, etc.) in a slope slope prevention method for resisting slope slippage (such as arc sliding or compound sliding). A slope independent pressure receiving device to be installed, and a plurality of support piles to be driven around ground anchors, and a pressure receiving device to be attached to the slope side end of the support piles and to anchor the ground anchors. And a member (a pressure receiving plate made of steel, concrete, or the like).

In the slope independent pressure receiving device, the supporting pile is formed by inserting a pile body (rebar or steel rod anchor) into a drilling hole and then filling a grout material in a tip portion of the drilling hole. ). Further, if necessary, an enlarged bottom is formed at the tip of the excavation hole, and reinforcing reinforcement is provided at the tip of the support pile (claim 5).

The pressure receiving member is a member which is provided with a gap between the pressure receiving member and the slope surface (claim 6). However, the pressure receiving member may be a flat plate-like supporting plate having a back surface in contact with the slope surface. (Claim 7). In addition, the shape of the pressure receiving member is such that a transmission pipe such as a ground anchor or a lock bolt is located at the center in a plan view, and a plurality of leg plates project radially from the star, so that the area covering the slope is reduced. preferable.

In the above construction, the anchor force of the ground anchor or the lock bolt in the slope prevention method is not received on the slope as in the conventional precast concrete product of the PC frame.
Since the transmission is conducted underground by the pile support of multiple support piles, a large supporting plate unlike the conventional one is not required, and only the support pile protrudes on the slope surface, so that 95% or more of the slope is greened. Can be.

The slope independent pressure receiving device comprises a plurality of supporting piles and a pressure receiving plate, and the anchors are supported by the supporting piles via the pressure receiving plate, thereby eliminating the need for a conventional large supporting plate. In addition, the pressure receiving device can be reduced in weight, the construction efficiency can be improved, and the construction cost can be reduced.

A slope-side independent pressure receiving device having a plurality of support piles is evenly scattered around the slope, and a large number of support piles are cast on the slope (Kenyama effect), thereby reducing the slope. It is reinforced over a predetermined depth to prevent collapse. Further, in combination with the rooting of the vegetation work that is performed on almost the entire slope, a stronger collapse prevention layer can be formed.

[0012] Although the surface of the slope is loosened due to the release of stress due to the cutting of the soil (rebound phenomenon), the slope independent pressure receiving device does not suppress the soil in the loosened portion, but reduces the anchor reaction force in the soil as a pile. Because it supports, the anchor force can be reliably transmitted to the ground where there is no loosening, and even if the cut slope does not have the bearing capacity, without increasing the pressure receiving area as usual, , And a uniform support force can be obtained.

[0013] Since a reaction of anchor force is taken in the ground by the pile support, even if there is a boulder or the like on the cut slope, it is not affected and a uniform support force can be obtained.
The construction can be performed quickly, and there is no possibility that the pressure receiving device is broken or damaged.

Since the pressure receiving plate is supported by a plurality of supporting piles and the anchoring force is shared by ground anchors, lock bolts and the like, the number and thickness of the supporting piles are changed to flexibly cope with various anchoring forces. be able to.

In the case where the design anchor force of the ground anchor, the lock bolt, etc. is large and the supporting force of a normal-sized support pile is insufficient, an expanded bottom portion is formed at the tip of the support pile, and reinforcement is provided on the expanded bottom portion. By providing the streaks, it is possible to obtain a supporting force that resists the design anchor force, and it is possible to respond to the ground part as it is without increasing the pressure receiving area as in the past, and it depends on the magnitude of the design anchor force. Without this, a greening area of 95% or more can always be secured, and a lightweight device can be obtained. In addition, if the design anchor force is large, the diameter of the widened part should be large, and if the design anchor force is small, the diameter of the widened part should be small, and one slope independent pressure receiving device can be applied to a wide range of design anchor force. can do.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the drawings. FIG. 1 shows an example of a slope independent pressure receiving device according to the present invention. FIG. 2 shows an example of reinforcement reinforcement in a support pile of the slope independent pressure receiving device of FIG. FIG. 3 shows another example of reinforcement reinforcement. FIG. 4 shows a state before and after vegetation on a slope by the slope stabilization method according to the present invention.

In FIG. 1, a slope independent pressure receiving device (tripod-shaped tri-pad anchor) 1 of the present invention is disposed at a construction position of a ground anchor or a lock bolt A 3.
It is composed of a book support pile (anchor) 2 and a pressure receiving plate (pad) 3 attached to an end of the support pile 2 slightly protruding from a slope surface to fix a ground anchor or a lock bolt A.

The support pile 2 has a drill hole 4 having a depth of about 1 m which is drilled at equal intervals on the same circle around the ground anchor or the lock bolt A, and is inserted into the drill hole 4. Reinforcing bar or steel rod anchor 5, enlarged bottom portion 6 formed by expanding the diameter of a drilling blade at the tip of excavation hole 4, reinforcing reinforcing bar 7 provided at the tip of rebar or steel rod anchor 5
And a grout material (cement milk, cement mortar, etc.) 8 filled in the tip of the drilling hole 4. At the tip of the rebar or steel rod anchor 5, a reinforcing reinforcing bar 7 and a grout material 8 form an expanded bottom support root 9. It is formed. In addition, it is preferable to drill three excavation holes 4 so that the two support piles 2 are located below the slope.

The enlarged bottom portion 6 and the reinforcing bar 7 are provided when the design anchor force is large.
As shown in FIG. 2, it is preferable to adopt a configuration in which the diameter is increased in the expanded bottom portion 6. That is, a pair of reinforcing bars 7a, 7a on the distal end side of the reinforcing reinforcing bar 7 are connected by a hinge member 7b, and the other end of each reinforcing bar 7a is connected to the ring member 7c by the hinge member 7c.
The ring member 7c is fixed to the reinforcing bar or the steel bar anchor 5 by a triangular mounting member 7d except for the foremost ring member except that the ring member 7c is connected outwardly and can be bent outward.

As will be described later, a reinforcing rod or a steel rod anchor 5 is inserted into the excavation hole 4, the tip of the reinforcing reinforcing bar 7 abuts against the bottom surface of the expanded bottom 6, and the reinforcing rod or the steel rod anchor 5 is further inserted.
, The pair of reinforcing bars 7a, 7a bend outward and expand in diameter. Thereby, the supporting force of the support pile 2 increases.
Note that the reinforcing reinforcing bar 7 is not limited to this, and may be, for example, a spiral reinforcing bar as shown in FIG. 3 or another configuration. The reinforcing bar or the steel rod anchor 5 has a length slightly protruding from the slope surface after setting.

The pressure receiving plate 3 is a steel member made of a steel plate or a casting, and is formed by a ground anchor or a transmission tube 10 of a lock bolt A and three leg plates 11 perpendicular to a slope attached to the three support piles 2. It is formed in a star shape when viewed, and a space is formed between the leg plates 11 and 11 when viewed in a plan view, where vegetation can be applied, and the entire slope can be almost greened.

Further, a steel pile receiving member 12 having a U-shaped cross section is engaged with the lower surface of the tip end of each leg plate 11 at the side of the side of the reinforcing bar of the supporting pile 2 or the steel rod anchor 5. Are fixed, and are set on the three support piles 2 in a state of floating above the slope surface. A steel upper transmission plate 13 of a ground anchor or a lock bolt A is set on the upper surface of the transmission tube 10, and a steel guide tube 14 is fixed to the lower surface of the transmission tube 10. The pressure receiving plate 3 is preferably made of a steel member, but is not limited thereto, and may be made of concrete or another material. Further, the shape of the pressure receiving plate 3 is preferably a star, but may be another shape.

Using the slope independent pressure receiving device 1 having the above configuration, the slope is constructed in the following order. Note that this is a case where the expanded bottom is provided by a three-legged tri-pad anchor.

(1) The slope is cut with a rotary percussion drill or the like, and a ground anchor or rock bolt A is inserted into the hole, grout is injected, and the underground tip side is fixed. The ground anchors or the lock bolts A are arranged so as to be scattered at equal intervals in the vertical and horizontal directions of the slope (see FIG. 4).

(2) Using the same rotary percussion drill or the like, three drill holes 4 (for example, φ150
mm, depth 1m). Here, at the time of drilling, a casing of φ150 mm was penetrated 1 m into the ground,
The tip of the drill is pre-drilled by about 30 cm from the tip of the casing, and the drilling blade for expanding the drilling end is expanded to form a widened portion 6 having a predetermined enlarged diameter. The drilling is performed while removing excavated earth and sand by water or air.

(3) After the drilling of the drilling hole 4 is completed, a reinforcing bar or a steel rod anchor 5 having a reinforcing bar 7 integrally provided at the tip end is inserted into the drilling hole 4, and the reinforcing bar 7 shown in FIG. In the case of the enlarged reinforcing bar, the distal end side reinforcing bar is expanded in diameter, and the grout material 8 is injected into the distal end portion of the excavation hole 4 to fix the distal end portion of the reinforcing bar or the steel rod anchor 5. At this time, a reinforcing bar or steel bar anchor 5
A suitable fixing device is provided on the slope side of the above, the position and height of the reinforcing bar or the steel bar anchor 5 are adjusted by the fixing device to carry out the fixing, and the side of the reinforcing bar or the steel bar anchor 5 is fixed. By positioning the pressure receiving plate 3 at a predetermined position, the pressure receiving plate 3 in the next step can be easily installed.

(4) The support pile 2 is completed as described above, and the development of the strength of the grout material 8 is awaited.
The pressure receiving plate 3 is set at the tip of the. At this time, the pressure receiving plate 3 is installed so that the pre-constructed ground anchor strand and the steel rod of the lock bolt are positioned at the center of the transmission pipe 10 of the pressure receiving plate 3.

(5) An anchor head is attached to the upper transmission plate 13 of the pressure receiving plate 3, and the strand or the steel rod is tensioned by the tension jack and fixed to the anchor head, so that the designed anchor force is applied to the strand or the steel rod. Introduce.

(6) A rust preventive material is injected from a hole formed in the upper transmission plate 13 for rust prevention of the strand of the ground anchor method or the steel rod of the rock bolt method. (7) As shown in FIG. 4, vegetation B is constructed on the slope. Since the slope independent pressure receiving device (tri-pad anchor) 1 of the present invention for three piles has a star shape in plan view and does not require a pressure receiving plate by supporting the pile, the area occupying the slope is small. Extremely small, the greening area of the slope can be 95% or more.

In addition, the ground anchor or the lock bolt A prevents the sliding of the arc on the slope and the combined slip, and the reinforcement of the slope by the support pile 2 (Kenyama effect) and the root entanglement of the vegetation B cause the slope to be reduced. A slope collapse prevention layer C of about 1 m from the surface is formed, and small collapse of the slope is prevented.

Further, since the pressure receiving plate 3 is separated from the slope surface and the ground anchor or the rock bolt A takes a reaction force in the ground by the pile support by the support pile 2, the cut slope having the boulders and the soil bearing capacity are taken. Since there is no need to secure a pressure receiving area corresponding to the design anchor force for a cut slope without a slope, the construction accuracy is not affected in most areas of the cut slope.

Further, while the weight of the conventional precast concrete product is 1.3 to 5.1 t, the weight of the steel pressure receiving plate 3 of the present invention is about 150 to 270 kg, which is a great reduction in weight. In addition, since the construction can be performed with a heavy machine of about a backhoe and the use of a dedicated large lifting machine is not required, the construction cost can be reduced and the construction efficiency can be improved.

In the above illustrated example, the pressure receiving plate 3
Has been described in which the pressure receiving plate 3 is set apart from the slope surface, but the pressure receiving plate 3 may be a steel or concrete flat bearing plate to support the slope surface. In this case, although slightly affected by the construction accuracy of the cut slope, the bearing effect of the pressure receiving plate 3 can be added to the reinforcing effect of the support pile 2 on the slope.

Although the above description has been given of the tri-pad anchor having three support piles 2, the present invention is not limited to this.
Two support piles or four or more support piles 2 may be used depending on the anchor force or the like.

[0035]

According to the present invention, after the ground anchors which resist the slip of the slope are scattered on the slope, a plurality of support piles and the pressure receiving A slope independent pressure receiving device consisting of members is installed,
Since the anchor force of the ground anchors is transmitted to the ground via the pressure receiving member and the support pile, the following effects can be obtained.

(1) Instead of receiving the anchoring force of a ground anchor or a rock bolt on a slope as in a conventional precast concrete product of a PC frame,
Since the transmission is conducted underground by the pile support of multiple support piles, a large supporting plate unlike the conventional one is not required, and only the support pile protrudes on the slope surface, so that 95% or more of the slope is greened. It is possible to create a reinforcement / prevention slope that considers the environment and landscape.

(2) Since the pile is supported by the supporting pile and the pressure receiving plate, a large supporting plate as in the related art is not required.
It is possible to reduce the weight of the pressure receiving device, improve construction efficiency,
The construction cost can be reduced.

(3) By arranging a large number of support piles evenly on the slope (the Kenzan effect), the slope is reinforced over a predetermined depth, and collapse can be prevented. Further, in combination with the rooting of the vegetation work that is performed on almost the entire slope, a stronger collapse prevention layer can be formed.

(4) Although the surface of the slope is loosened due to the release of stress due to the cutting of the soil (rebound phenomenon), the slope independent pressure receiving device does not suppress the soil in the loosened part, but anchors it as a pile in the soil. To support the reaction force, the anchor force can be reliably transmitted to the ground where there is no looseness, and the pressure receiving area should be increased as before even when the cut slope has no bearing capacity. Instead, a normal-sized slope-side independent pressure receiving device can be installed, and a uniform supporting force can be obtained. In addition, there is an advantage that it is not affected by settlement due to insufficient ground bearing capacity, and also follows settlement of anchors.

(5) Since the reaction force of the anchor force is taken in the ground by supporting the pile, even if there is a boulder or the like on the cut slope, it is not affected and a uniform supporting force can be obtained.
The construction can be performed quickly, and there is no possibility that the pressure receiving device is broken or damaged.

(6) The pressure receiving plate is supported by a plurality of supporting piles, and the anchoring force is shared by ground anchors, lock bolts, and the like. Therefore, the number and thickness of the supporting piles are changed to flexibly support various anchoring forces. Can be handled.

(7) When the design anchor force of a ground anchor, a lock bolt, or the like is large, an expanded bottom is formed at the tip of the support pile, and reinforcing reinforcement is provided at this expanded bottom.
It is possible to obtain the supporting force that resists the design anchor force, and it is possible to cope with the ground part as it is, without increasing the pressure receiving area as in the past, without being affected by the magnitude of the design anchor force, A greening area of 95% or more can be secured, and a lightweight device can be obtained. In addition, if the design anchor force is large, the diameter of the widened part should be large, and if the design anchor force is small, the diameter of the widened part should be small, and one slope independent pressure receiving device can be applied to a wide range of design anchor force. can do.

[Brief description of the drawings]

FIG. 1 is an example of a slope independent pressure receiving device of the present invention, and (a)
2 is a cross-sectional view of the slope showing a state where the apparatus is installed on the slope, (b) is a plan view of the apparatus, and (c) is a side view of the apparatus.

FIG. 2 is a cross-sectional view of an example of a support pile of the slope independent pressure receiving device of the present invention in a driving state.

FIG. 3 is a cross-sectional view of a slope showing another example of different reinforcement reinforcement of a support pile of the slope independent pressure receiving device of the present invention.

FIG. 4 is a cross-sectional view showing a state before and after vegetation on a slope by a slope stabilization method according to the present invention.

[Explanation of symbols]

 A: Ground anchor or rock bolt B: Vegetation work C: Slope failure prevention layer 1: Slope independent pressure receiving device 2: Support pile 3: Pressure receiving plate 4: Drilling hole 5: Rebar or steel Rod anchor 6 ... Expanded bottom 7 ... Reinforcing reinforcement 7a ... Reinforcing bar 7b ... Hinge member 7c ... Ring member 7d ... Mounting member 8 ... Grout material 9 ... Expanded bottom support root 10 ... Transmission pipe 11 ... Leg plate 12 ... … Pile receiving fitting 13 …… Upper transmission plate 14 …… Guide tube

Claims (7)

[Claims] Claims: 1. In a slope prevention method in which a ground anchor is resistant to slippage on a slope, after the ground anchors are scattered on the slope, the ground anchors are installed at a construction position of the ground anchors. A slope stabilization method comprising: disposing a slope independent pressure receiving device including a plurality of support piles and a pressure receiving member, and transmitting an anchor force of ground anchors to the ground through the pressure receiving member and the support pile. Law. 2. The slope stabilization method according to claim 1, wherein vegetation is performed between each slope independent pressure receiving device. 3. A slope independent pressure receiving device disposed at a construction position of ground anchors in a slope anti-slipping method for resisting slip of a slope, wherein a plurality of slope anchors are placed around the ground anchors. A slope independent pressure receiving device comprising: a support pile; and a pressure receiving member attached to an end of the support pile on a slope side to which ground anchors are fixed. 4. The slope independent pressure receiving device according to claim 3, wherein the support pile is formed by inserting a pile main body into a drilling hole and then filling a grout material in a tip portion of the drilling hole. Features a slope independent pressure receiving device. 5. The slope independent pressure receiving device according to claim 4, wherein an expanded bottom portion is formed at the tip of the excavation hole, and reinforcing reinforcement is provided at the tip of the support pile. Pressure receiving device. 6. The slope independent pressure receiving device according to claim 2, 3, 4, or 5, wherein the pressure receiving member is a member that is installed with a gap between the slope receiving surface and the slope surface. A slope independent pressure receiving device, characterized in that: 7. The slope independent pressure receiving device according to claim 2, 3, 4 or 5, wherein the pressure receiving member is a support plate whose back surface is in contact with the slope surface. Slope independent pressure receiving device.