JP2002088769A - Slope stabilizing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase slope stabilizing effect without cutting trees. SOLUTION: In order to increase the slope stabilizing effect, a slope surface stabilizing method by using first anchors 1, bearing plates, and a head connecting member 2, is carried out not only in an area S1 which is in danger of slope failure in view of ground conditions of a slope surface, but also in an area S2 (i.e., area in no danger of the slope failure) upper than the area S1 in danger of the slope failure, by using second anchors 1', the bearing plates, and the head connecting member 2, such that a row of the first anchors 1 and the head connecting member 2 set in the area S1 in danger of the slope failure are extended toward an upper side of the slope surface (1st one of Fig. 1). Thus, the second anchors 1' and the head connecting member 2 connected thereto, which are set in the area S2 in no danger of the slope failure, minimize movement of collapse earth at the time of the slope failure (2nd one of Fig. 1). Setting of the second anchors 1' in the area S2 in no danger of the slope failure need not cutting of trees, which is preferable as the slope stabilizing method applied to the natural slope surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a head connecting member for connecting a plurality of rows of anchors installed at intervals from the upper part to the lower part of a slope with a head connecting member. The present invention relates to a slope stabilization method in which a bearing plate is attached and tightened to apply a bearing force to the ground.

[0002]

2. Description of the Related Art Conventionally, as a method for preventing a slope from collapsing, as shown in FIG. 10, an anchor 1 is placed at an interval from an upper portion to a lower portion of the slope, and a head of the anchor 1 is formed. A slope stabilization method is known in which a head connecting member 2 such as a wire rope is connected therebetween, and a supporting plate (not shown) is attached to each anchor 1 and tightened to apply a supporting force to the ground. ing. According to this slope stabilization method, when the anchor 1 is deformed at the time of moving the slope, together with the shear resistance of the anchor 1 and the supporting force by the support plate, the head connecting member 2 has an effect of retaining the anchor 1. To prevent or reduce slope collapse.

[0003] By the way, in the frame method for preventing slope collapse and other conventional slope stabilization methods, a design concept of stabilizing construction only in an area where a slope collapse is likely to occur is common. Conventionally, even with the above-described slope stabilizing method using the anchor 1, the head connecting member 2, and the support plate, the
As shown, the anchor 1 (indicating an estimated slip line a when the slope disintegrate in broken lines) region which is determined that there is a risk of landslides were Da設only in S _1.

Further, a fixed structure made of concrete or the like is installed at the top of the slope (that is, an area where the slope is not likely to collapse), and a wire rope or the like for connecting the heads of the vertical anchors cast on the slope. In some cases, the connecting member is further extended upward to be connected to the fixed structure, and the effect of retaining the connecting member is borne solely by the fixed structure (Japanese Patent Application Laid-Open No. Sho 56).
-9527).

[0005]

The slope stabilization method shown in FIG. 10 can be performed without cutting down trees.
This method is excellent as a slope stabilization method for natural slopes, but depending on the condition of the ground, the effect of preventing or reducing slope failures may be insufficient. In this case, in the conventional design concept of performing stabilization work only in an area where a slope collapse is likely to occur, the number of anchors 1 is increased, and each anchor 1
Although measures such as increasing the rigidity of the anchor 1 and driving the anchor 1 deeper are conceivable, depending on the terrain and the like, it may not be possible to obtain a sufficiently high effect to increase the construction cost. Also, as described in JP-A-56-9527, a fixed structure such as a concrete structure is installed at the top of the slope or in an area where the slope is not likely to collapse, and the head connecting member 2 is connected thereto. However, in the method of installing a fixed structure such as a concrete structure, it is necessary to cut down trees, which is not preferable as a method of protecting natural slopes.

The present invention has been made in view of the above circumstances, and makes it possible to increase the effect of suppressing or reducing slope collapse without requiring tree felling, and to provide a slope stabilization method suitable for natural slopes. The purpose is to provide the law.

[0007]

In order to solve the above-mentioned problems, the present invention provides a head connecting member for connecting a plurality of rows of anchors which are arranged at intervals from the upper part of the slope to the lower part thereof. In the slope stabilization method of connecting and attaching a bearing plate to each anchor and tightening it to give bearing pressure to the ground, a first anchor is provided in an area where the slope may collapse due to the ground conditions of the slope. While the above-mentioned slope stabilization method using the support plate and the head connecting member is performed, the anchor row and the head connecting member in the area where the slope collapse is likely to be located above the area where the slope collapse is likely to occur. In a mode extended to the upper side, a plurality of second anchors are installed at intervals in the up-down direction, and the heads of the plurality of second anchors in the up-down direction are connected by a head connection member. And each second Linker to attach the bearing capacity plate, characterized in providing the Bearing force by fastening it against the ground.

According to a second aspect of the present invention, in the slope stabilization method of the first aspect, the heads of the anchors adjacent to each other in the lateral direction or the oblique direction are connected by an auxiliary head connecting member.

According to a third aspect of the present invention, in the slope stabilization method of the second aspect, the arrangement of the anchors is a staggered arrangement in which adjacent left and right anchors are vertically displaced from each other.

According to a fourth aspect of the present invention, in the slope stabilization method according to the third aspect, the head connecting member and the auxiliary head connecting member for connecting the heads of the anchors have a triangular shape.

[0011]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIGS. FIG. 1 schematically shows a cross section of a slope on which a slope stabilization method according to an embodiment of the present invention is applied, wherein (a) shows a state before the slope collapse and (b) shows a state after the slope collapse. FIG. 2 is an enlarged plan view of a main part of the slope of FIG. As shown in these figures, in the slope stabilization method of this embodiment, a large number of anchors (a first anchor 1 and a second anchor 1 ′, which will be described later) are formed on the top of the slope so as to form a plurality of rows. Are installed at an interval from the bottom to the bottom, and the heads of the anchors 1 (1 ′) lined up and down are connected by a head connecting member 2, and each anchor 1 (1 ′)
The supporting plate 3 is attached to the head of the
To provide support for the ground. The arrangement of the anchors 1 (1 ′) in this embodiment is such that the anchors 1 (1 ′) adjacent in the horizontal direction are staggered vertically displaced from each other.
An arrangement is such that three adjacent anchors 1 (1 ′) form a triangle, and the anchors 1 (1 ′) that are adjacent diagonally
The heads of (1 ′) are connected by the auxiliary head connecting member 4.

[0012] As described above, although the appearance may construction in the same manner as conventional, in the present invention, in the region S ₁ in the ground conditions of the slope at risk of landslide, as described above, the first anchor 1, The slope stabilization method using the support plate 3, the head connecting member 2, and the auxiliary head connecting member 4 is performed, and the upper part S ₂ above the area S _{1 where the} slope collapse is likely (that is, the area where the slope failure is not likely). in a manner that the column and head coupling member 2 of the first anchor 1 in the region S ₁ with a risk of the landslide is extended to the upper slope side, a plurality of second
Are installed at intervals in the up-down direction, and the heads of the plurality of second anchors 1 'in the up-down direction are connected by a head connecting member 2, and each of the second anchors 1' The supporting plate 3 is attached to the ′, and tightened to apply a supporting pressure to the ground. In the illustrated example, the second anchor 1 ′ is disposed at the upper part S ₂ of the area S ₁ at which the slope may collapse.
Are seven as indicated by. Also, the entirety of the vertical anchor 1 (1 ') is connected to one head connecting member 2 (1).
Are connected by In FIG. 1A, the estimated slip line a at the time of the slope failure is shown by a broken line, and this is assumed to be the actual slip line a in FIG. 1B.

Various cases are conceivable for the above-mentioned slope, which is regarded as "the area where the slope may collapse due to the ground condition of the slope". For example, there is a case where there is a danger of slope collapse from the viewpoint of the terrain. That is, on a mere flat slope (slope in which the cross section of the entire slope is a straight line), it is not judged from the terrain that there is a risk of slope collapse for a part of the entire slope, but the curved cross section as shown in FIG. the terrain, according to the recent studies of slope failure causes a fear that inflection points (Fig. 1 (b), the upper end position near the estimated slip lines a) from the lower region of the curve (i.e., S ₁₎ of slope failure There is an area. Also, not only the topographical factors, but also the soil quality and other factors,
In some cases, it may be determined that there is a risk of slope collapse for a part of the entire slope.

[0014] The upper than the region _{S 1} with a risk of slope failure S
The structure itself of the second anchor 1 'part to be installed in _two, a first anchor 1 substructure basically the same as that of the installation in the region S ₁ with a risk of landslides, the work, the above As described above, the second anchor 1 'and the first anchor 1 can be collectively constructed without being divided. That is, the area S ₁ that may slope failure and its upper S ₂
Can be constructed collectively. An example of a specific work procedure of the slope stabilization method of the present invention will be described with reference to FIGS. 3 and 4 showing the detailed structure of each part of the embodiment.
First, the area S ₁ that may slope failures entire region of the upper S _2, (in Figure 1 the upper right: upper in Fig. 2) slope of the upper head connection member 2 of the long plurality of from to bottom They are arranged at intervals in the horizontal direction (the left-right direction in FIG. 2). Next, anchors 1 (1 ′) are installed at appropriate intervals in the vertical direction along the head connecting member 2. Anchors installed, the slope in the upper S ₂ without danger of collapse second anchor 1`, the risk first anchor 1 in the region S ₁ of the landslide. The anchor 1 (1 ′) of the embodiment is
This is a so-called lock bolt formed with a screw. Then
A collar 5 is provided at the upper end on the outer periphery just below the surface of each anchor 1 (1 ').
a short cylindrical body 5 having a. A connecting member 7 for connecting the head connecting member 2 is attached to the tubular body 5. This connecting member 7 is attached to the cylindrical body 5 by an attaching portion 8.
And a grip portion 9 provided integrally with the mounting portion 8 and gripping the head connecting member 2 extending linearly. The mounting portion 8 is fixed to the cylindrical body 5 by holding the outer periphery of the cylindrical body 5 with a pair of bands 8a and tightening a bolt 8b. The grip portion 9 grips the head connecting member 2 passed through the cylindrical portion by, for example, a set bolt 9a.

Next, the support plate 3 is put on the head of the anchor 1 (1 '), and put on the flange 5a of the tubular body 5. Then
Nut 12 is anchored 1 with washer 11
Screw into (1 ') and tighten. As a result, the support plate 3 sinks while applying a tensile force as a reaction force to the anchor 1 (1 '), thereby generating a support force against the ground. At this time, the support plate 3 also causes the head connecting member 2 attached to the tubular body 5 to sink, so that the head connecting member 2
In addition, not only a simple tension in the horizontal direction but also a tension in the vertical direction is applied to increase the ground holding effect in which the head connecting member 2 presses the ground to press the ground, thereby contributing to stabilization of the slope. FIG. 3 shows a state in which the support plate 3 has sunk.

The entire construction area S₁, S₂Each anchor 1
For (1 '), set the support plate 3 as described above and forcibly settle it.
After lowering, as shown in detail in FIG.
For car 1 (1 '), two cars obliquely adjacent to each other
The auxiliary head connecting member 4 connects the heads of the anchors 1 (1 ').
I do. In this embodiment, an auxiliary head having a ring at both ends is used.
The two anchors 1 adjacent to each other are
(1 ') Connected by one auxiliary head connecting member 4 for every interval
I have. The auxiliary head connecting member 4 is an anchor of the head connecting member 2.
-1 (1 ') as well as the anchoring effect
1 (1 ') has a retaining effect, but in an oblique direction.
Connecting the anchors 1 (1 ') adjacent to each other
To dissipate the force in the diagonal direction
And contributes to stabilization of the slope. In addition, one
In the anchor 1 (1 '), the support plate 3 is forcibly settled,
Connected to the anchor 1 (1 ') in contact with the auxiliary head connecting member 4
Work to be performed sequentially on the entire slope S ₁, S₂Anchor 1
The procedure may be repeated for (1 ') or the entire slope S
₁, S₂Auxiliary head connecting part for anchor 1 (1 ')
After connecting the members 4, the bearing pressure of each anchor 1 (1 ')
A procedure for forcibly sinking the plate 3 may be used.

Next, a cap 14 is put on the head of the anchor 1 (1 '), and a bolt 15 is drilled on the upper end surface of the anchor 1 (1') from above the hole 14a formed on the upper surface of the cap 14. The cap 14 is fixed on the support plate 3 by screwing the cap 3b.

As described above, the second anchor 1 ′ is cast by extending not only the area S ₁ where the slope collapse is likely to occur but also the area S _{2 above the} area where the slope failure is not likely to occur. In the stabilized construction slope (FIG. 1A) connected by the partial connecting member 2 and the support plate 3 is installed, if a part of the slope is collapsed due to rainfall or earthquake after construction, FIG. As shown in b), the first anchor 1 in the collapsed soil mass 20 bends and deforms in accordance with the movement of the collapsed mass 20, but the head connecting member 2 exerts a retaining effect of retaining the anchor 1 during the deformation. In addition, the amount of movement of the collapsed mass 20 can be sufficiently reduced. In this case, outside the collapsed mass 20 (upper S
_{The second} anchor 1 ′ in ₂ ) is deformed by receiving the tension of the head connecting member 2. Due to the load deformation characteristics of the head connecting member 2, the deformation of the second anchor 1 ′ is as shown in FIG. In the example of the embodiment, >>>> ≒ 0, and has little effect on the second anchor 1 ′, and does not affect the entire second anchor 1 ′ outside the collapsed soil mass 20. . Moreover, in consideration of the load deformation characteristics of the head connecting member 2, it has been found that it is necessary to drive at least about 3 to 5 steps from a region where there is a risk of collapse. Further, in the above-described embodiment, not only the anchors 1 (1 ′) arranged in the vertical direction are connected by the head connecting member 2, but also the anchors 1 (1 ′) adjacent in the oblique direction are connected to the auxiliary head connecting member. 4, the anchor 1 is connected as described above.
(1 ′) The retaining force generated in the head connecting member 2 at the time of deformation is dispersed to the auxiliary head connecting member 4. For this reason, the influence of the slope movement at the time of the slope collapse rarely affects the upper part.

FIG. 5 shows a model slope experiment performed on the slope stabilization method of the present invention. FIG. 5 shows the model slope. The tip of a box box 30 filled with soil cement is connected to a floor 31 by a hinge 32, and The fixed box 33 and the free moving box 34 each filled with sand are placed side by side on the upper surface of the box 30, and the anchor 1 (1 '), the head connecting member 2, and the like, as in the above-described slope stabilization method of the present invention. The auxiliary head connecting member 4 and the supporting plate 3 are installed, and the fixed box 33 is fixed to the base box 30 with bolts so as not to move. The free moving box 34 moves in the direction of the arrow with the support force of the anchor 1 or the like (collapsed soil mass). This is an experiment in which the rear end of the base box 30 is lifted by a crane and the angle θ of the base box (corresponding to the slope of the slope) is gradually increased. Free movement box 34 corresponds to the area S ₁ that may slope failure, fixed box 33 corresponds to the upper S ₂ no risk of landslides. In this model slope, there is no head connecting member for connecting the left anchor row of the three rows of anchors 1 (1 '). This is for detecting the action as one unit.

FIG. 6 is a view showing the situation of the model slope experiment, in which the angle θ of the base box 30 is 50 °. As shown, when the free moving box 34 moves (slope collapse). ,
Only the crack 36 is generated near the boundary with the fixed box 33, and the influence on the fixed box 33 side is extremely small. That is,
It is less affected if the upper S ₂ in the area of the risk of landslides. In addition, the model slope of FIG. 6 connects the heads of the anchors 1 (1 ′) vertically adjacent to each other with the head connecting member 2 and the anchors 1 (1 ′) adjacent diagonally.
(1 ′) is a case in which the heads are connected by the auxiliary head connecting member 4, but when the auxiliary head connecting member 4 is not connected, cracks also occur in the upper part of the fixed box 33. did. Therefore, the anchor 1 adjacent in the oblique direction
It can be seen that it is desirable to connect between (1 ′) with the auxiliary head connecting member 4 in order to stabilize the slope.

In the above-described embodiment, each one of the anchors 1 vertically adjacent to one of the head connecting members 2 passed vertically.
Although the heads of (1 ') are fixed (see Fig. 7 (a)), as shown in Fig. 7 (b), one head is provided for each of the vertically adjacent anchors 1 (1'). The connection may be performed using the head connection member 2.

In the above-described embodiment, each of the anchors 1 (1 ') adjacent in the diagonal direction is connected using one auxiliary head connecting member 4 (see FIG. 8A). 8), a plurality of diagonally adjacent anchors 1 (1 ′) may be fixed to one diagonally-assisted auxiliary head connecting member 4 as shown in FIG. Also, as shown in FIG. 8 (c), one auxiliary head connecting member 4 is wound between three adjacent anchors 1 (1 ′) in a triangular shape, and the anchors which are obliquely adjacent to each other. 1
(1 ') may be connected. In this case, it is also possible to use the vertical portion of the auxiliary head connecting member 4 forming a triangle as the head connecting member 2 for connecting the upper and lower anchors 1 (1 ').

Further, the head connecting member 2 and the auxiliary head connecting member 4 of the embodiment are striated bodies (including band-shaped ones) such as wire ropes, but may be replaced with striated bodies or striated bodies. You can also use the net with your body. In this case, as shown in FIG. 9, it is preferable that the net 37 is stretched around a portion surrounded by the head connecting member 2 and the auxiliary head connecting member 4. It is also possible to adopt a configuration in which the net 37 itself performs the anchor head connecting function of the head connecting member 2 and the auxiliary head connecting member 4 without providing the connecting member 4.

In the embodiment, the anchor 1 (1 ')
Are staggered, and three adjacent anchors 1
(1 ′) Although the head connecting member 2 and the auxiliary head connecting member 4 that connect between them form a triangle, the anchor 1 (1 ′)
Of four adjacent anchors 1
(1 ′) The head connecting member 2 and the auxiliary head connecting member 4 that connect between them may be formed in a square.

[0025]

According to slope stabilization method of the present invention, the area S ₁ in the ground conditions of the slope at risk of landslide, anchor, Bearing plate, simply applying a slope stabilization method according to head coupling member not to (no possibility of areas i.e. slope failure) S ₂ than the region S ₁ with a risk of landslides upper, anchor column and head connecting member upper slope side of the area S ₁ that may slope failure Since the same slope stabilization method is applied in a mode that is extended to the above, it has become possible to minimize the movement of the collapsed soil mass during slope failure. That is, the slope collapse could be reduced, and the slope stabilizing effect could be enhanced. Unlike the conventional method, in which a fixed structure such as a concrete structure is installed in an area where there is no danger of slope collapse and a head connecting member is connected thereto, there is no need to cut down trees, and natural slopes do not occur. It is suitable as a slope stabilization method.

When not only the anchors arranged in the vertical direction are connected by the head connecting member but also the anchors adjacent in the horizontal or diagonal direction are connected by the auxiliary head connecting member, Since the retaining force generated in the head connecting member at the time of deformation is dispersed to the auxiliary head connecting member,
The influence of the slope movement at the time of the slope collapse can be reduced from reaching the upper part, and the slope stability effect is further improved.

[Brief description of the drawings]

FIG. 1 schematically shows a cross section of a slope subjected to the slope stabilization method of the present invention, wherein (a) shows a state before the slope collapse,
(B) shows the state after the slope collapse.

FIG. 2 is an enlarged plan view of a main part of a slope shown in FIG.

FIG. 3 is a detailed enlarged sectional view taken along the line AA of FIG. 2;

FIG. 4 is an enlarged plan view of a main part in FIG. 2;

FIG. 5 is a diagram illustrating the outline of an experiment performed to confirm the effect of the slope stabilization method of the present invention.

FIG. 6 is a diagram showing the experimental results of FIG.

FIG. 7 is a diagram illustrating a connection mode of a connection member that connects between heads of anchors that are vertically adjacent to each other.

FIG. 8 is a diagram illustrating a connection mode of a connection member that connects between heads of anchors adjacent in the lateral direction.

FIG. 9 is a diagram showing an embodiment in which a net is stretched between connecting members.

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

[Explanation of symbols]

1 first anchor 1 'upper region of the second anchor 2 head coupling member 3 Bearing plate 4 auxiliary head coupling member S ₁ a potentially landslide area S ₂ slope failure risk of a region of

Continued on the front page (72) Inventor Takato Inoue 1-4-2-705 Shinmachi, Hoya-shi, Tokyo F-term (reference) 2D044 EA01

Claims (4)

[Claims] 1. A method according to claim 1, wherein the heads of the anchors arranged in a plurality of rows and spaced from the upper part to the lower part of the slope are connected by a head connecting member, and a supporting plate is attached to each anchor. In the slope stabilization method that tightens this and gives bearing force to the ground, the first area in the area where the slope may collapse due to the ground conditions of the slope,
The above-described slope stabilization method using the anchor, the support plate, and the head connecting member is performed, and the anchor row and the head connection in the area where the slope collapse is likely to occur above the area where the slope collapse is likely to occur. A plurality of second anchors are installed at an interval in the up-down direction so that the member is extended to the upper side of the slope, and a head connection is made between the heads of the plurality of second anchors in the up-down direction. A slope stabilization method, comprising connecting a support member to each second anchor, fastening the support plate to each second anchor, and tightening the support plate to apply a support force to the ground. 2. The slope stabilization method according to claim 1, wherein the heads of the anchors adjacent to each other in the lateral direction or the oblique direction are connected by an auxiliary head connecting member. 3. The slope stabilization method according to claim 2, wherein the arrangement of the anchors is a staggered arrangement in which adjacent left and right anchors are vertically displaced from each other. 4. The slope stabilizing method according to claim 3, wherein the head connecting member and the auxiliary head connecting member for connecting the heads of the anchors have a triangular shape.