JP2019196605A - Sloped face reinforcement work - Google Patents

Abstract

To prevent pass-through and breakage of a slide layer in a sloped face with economical means.SOLUTION: One aspect of this invention provides a sloped face reinforcement work comprising: at least two anchors arranged in a second direction crossing a first direction on a sloped face inclined in the first direction and buried to a first depth in the sloped face; at least one auxiliary anchor arranged between at least two anchors and buried to a second depth that is shallower than the first depth in the sloped face; and a tension member connecting at least two anchors to the auxiliary anchor.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a slope reinforcement work.

The slope reinforcement work is performed in order to prevent and stabilize a natural slope or a slope formed by cut or embankment. FIG. 8 shows a typical example of such slope reinforcement work. In the illustrated example, the slope reinforcement work 2 constructed on the slope 1 includes an anchor 3 and a frame 4. Inside the slope 1, there is a sliding surface 5, a portion shallower than the sliding surface 5 is a sliding layer 6, and a portion deeper than the sliding surface 5 is a non-moving layer 7. For example, the anchor 3 constituted by a rock bolt is buried to a depth d ₁ deeper than the depth d of the sliding surface 5 and reaches the immobile layer 7. Thus, the slope reinforcement work 2 prevents the slope 1 from collapsing by the resistance force obtained in the cross-sectional support region 8 including the sliding layer 6 in the vicinity of the anchor 3 and the immobile layer 7 between the anchors 3. For example, the frame 4 constituted by a concrete worker is connected to each head of the anchor 3 to maintain the distance between the anchors 3, and by pressing the surface of the slope 1, the sliding layer 6 moves between the anchors 3. It also functions as a pressure receiving member that prevents it from slipping through and being destroyed. An example of such a technique is also described in Patent Document 1.

JP 2005-213744 A

  However, there is a case where the slipping layer cannot be prevented from being slipped through only by pressing the surface of the slope by the technique described in the above-mentioned Patent Document 1 or the like. The interval will be narrowed. However, in many cases, there is a margin in the resistance force of the anchor, and it is not necessary to narrow the anchor installation interval unless the breakthrough failure is taken into consideration. In such a case, it is not necessarily an economical measure to increase the number of anchors reaching the non-moving layer only to prevent slip-through destruction.

  Therefore, an object of the present invention is to provide a new and improved slope reinforcement work that can prevent slipping destruction of a sliding layer on a slope by an economical method.

According to an aspect of the present invention, there are at least two anchors arranged in a second direction intersecting the first direction on a slope inclined in the first direction and embedded in the slope to a first depth; , At least one auxiliary anchor disposed between at least two anchors and embedded in a slope to a second depth shallower than the first depth, and a tension member connecting the auxiliary anchors to the at least two anchors A slope reinforcement work is provided.
According to said structure, a clump adheres to an auxiliary | assistant anchor, and resistance force is transmitted, Therefore Even if it does not narrow the installation space | interval of an anchor, slipping-through destruction of a sliding layer can be prevented.

In the slope reinforcing work described above, the first depth may be deeper than the depth of the slip surface of the slope, and the second depth may be shallower than the depth of the slip surface.
In order to obtain resistance to prevent slope collapse, the anchor is buried deeper than the sliding surface. Is possible.

In the slope reinforcing work described above, the at least two anchors and the auxiliary anchor may be a steel pipe, a dimple pipe, or a deformed steel bar.
The auxiliary anchor may be a dimple tube or a deformed steel bar in order to improve adhesion to the soil mass. Also for the anchor, adopting the above configuration can be effective for improving the resistance.

In the slope reinforcing work described above, the auxiliary anchor may have a hook shape at the tip.
The auxiliary anchor can be formed in various shapes in order to improve adhesion to the soil mass. Since the soil of the relatively shallow layer forming the sliding layer is generally soft, it is possible to facilitate the press-fitting of the auxiliary anchor in the middle by making the tip into a bowl shape.

In the slope reinforcing work described above, the auxiliary anchor may include a plurality of auxiliary anchors that intersect with each other when viewed from any direction.
When a plurality of auxiliary anchors that intersect each other are provided, adhesion between the plurality of auxiliary anchors and the soil mass is improved by sandwiching the soil.

  As described above, according to the present invention, it is possible to prevent slipping of the sliding layer on the slope by an economical method.

It is a schematic perspective view of the slope reinforcement work concerning the 1st embodiment of the present invention. It is the II-II sectional view taken on the slope reinforcement work shown by FIG. It is a figure for demonstrating the effect | action of the tension member in the 1st Embodiment of this invention. It is a schematic sectional drawing of the slope reinforcement work which concerns on the 2nd Embodiment of this invention. It is a schematic sectional drawing of the slope reinforcement work which concerns on the 3rd Embodiment of this invention. It is a figure which shows the modification of this invention. It is a figure which shows the modification of this invention. It is a figure which shows the typical example of slope reinforcement construction.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
FIG. 1 is a schematic perspective view of a slope reinforcing work according to the first embodiment of the present invention. As shown in FIG. 1, the slope reinforcement work 10 applied to the slope 1 inclined in the first direction (the x direction in the figure) is in the second direction (y in the figure) intersecting the first direction. At least two anchors 11, auxiliary anchors 12, and tension members 13 arranged in the direction). For example, the anchor 11 may be formed of a lock bolt, a steel pipe (including a dimple pipe described later), or a deformed steel bar, similarly to a conventional slope reinforcing work. Although not shown, a blade for facilitating penetration into the ground may be provided at the end of the anchor 11. Further, a bearing plate that contacts the surface of the slope 1 may be provided on the head of the anchor 11. The peripheral surface of the anchor 11 may be filled with a material capable of solidifying with time such as mortar to increase the adhesion.

  At least one auxiliary anchor 12 is disposed between the two anchors 11 arranged in the y direction. The auxiliary anchor 12 can be formed of, for example, a lock bolt, a steel pipe, or a deformed steel bar as with the anchor 11, and details will be described later. In the example of FIG. 1, there are two rows of two anchors 11 arranged in the y direction, and one auxiliary anchor 12 is installed between each anchor 11. In another example, three or more anchors 11 may be arranged in one row, and there may be three or more rows of anchors 11. Two or more auxiliary anchors 12 may be disposed between the two anchors 11 arranged in the y direction. In the adjacent rows, the y-direction positions of the anchors 11 may not be the same. For example, the auxiliary anchor 12 may be disposed in the adjacent row at the y-direction position where the anchor 11 is located.

  The tension member 13 connects the auxiliary anchor 12 to the two anchors 11 arranged in the y direction. In the example of FIG. 1, the tension member 13 is a wire, and the two tension members 13 are fastened to the heads of the two anchors 11 while being inserted into the through holes formed in the heads of the auxiliary anchors 12. A tensile force is transmitted between the anchor 11 and the auxiliary anchor 12. The tension member 13 is not limited to a wire as long as it can transmit a tensile force as described above, and may be a steel member such as a shape steel, a steel pipe, a steel bar, or a steel plate. Alternatively, the tension member 13 may be formed of wood, a resin material, carbon fiber, or the like. The tension member 13 may have various shapes such as a wire shape, a rod shape, and a plate shape. A plurality of shapes or a plurality of materials may be used in combination. The connection method between the tension member 13 and the anchor 11 and between the tension member 13 and the auxiliary anchor 12 is appropriately changed according to the shape and material of the tension member 13. In addition, since the tension member 13 does not need to oppose the compressive force, the steel member can be thin or thin. Further, since the tension member 13 does not have to press the surface of the slope 1, it may be installed exposed from the slope 1 as in the example of FIG. 1 or may be in contact with the surface of the slope 1. Further, it may be embedded in the surface layer of the slope 1.

FIG. 2 is a cross-sectional view taken along the line II-II of the slope reinforcement shown in FIG. As shown in FIG. 2, in the slope reinforcing work 10, the anchor 11 is embedded in the slope 1 to the first depth d ₁ . In the example of FIG. 2, the first depth d ₁ is deeper than the depth d of the sliding surface 5 inside the slope 1. The auxiliary anchor 12 is embedded in the slope 1 to a second depth d _2. Second depth d ₂ is smaller than the depth d of the sliding surface 5, thus shallower than the first depth d _1. In the present embodiment, the slip surface 5 is a virtual surface that is predicted to be a boundary between the sliding layer 6 and the non-moving layer 7 when the slope 1 is collapsed. Previously identified by geomechanical analysis. Here, for example, “Road Bridge Specification / Implementation (I Common Edition / IV Substructure Edition)” (March 2012), pages 409-411, published by Japan Road Association, If the characteristic value β of the pile as shown below is used, d ₁ > 3 / β and d ₂ <3 / β can be defined. Incidentally, _{k H} is horizontal subgrade reaction coefficient (kN ^{/ m} 3), D is the pile diameter (m), EI is the pile bending stiffness (kN · ^{m 2).}

  In the slope reinforcing work 10 according to the present embodiment, the anchor 11 is buried deeper than the sliding surface 5 and reaches the immobile layer 7 to mainly exert a resistance force for preventing the slope 1 from collapsing. On the other hand, since the clod of the sliding layer 6 adheres to the auxiliary anchor 12, when the slope 1 is about to collapse, the resistance force of the anchor 11 is transmitted to the clod of the sliding layer 6 via the tension member 13 and the auxiliary anchor 12. . As a result, in this embodiment, a resistance force is exerted integrally in the cross-sectional area 14 including the sliding layer 6 in the vicinity of the anchor 11, the immovable layer 7 between the anchors 11, and the soil mass in the vicinity of the auxiliary anchor 12. . By appropriately setting the distance between the anchor 11 and the auxiliary anchor 12, the entire sliding layer 6 between the anchors 11 is integrally resisted at least to the depth of the auxiliary anchor 12 as in the illustrated example. Power can be exerted, and slip-through collapse can be effectively prevented. When the auxiliary anchor 12 is formed of a steel pipe, a dimple pipe, that is, a steel pipe in which a recess 12D having a predetermined shape is formed in the circumferential direction may be used as shown in the illustrated example in order to improve adhesion to the soil mass. Good. Examples of dimple pipes are described in “Structural steel pipes of Nippon Steel & Sumitomo Metal Group (highly functional product group)” (December 2015), page 6 issued by Nippon Steel & Sumitomo Metal Corporation. It is also effective to use a deformed steel bar in order to improve adhesion to the soil mass.

In the above example, the second depth d _{2 in} which the auxiliary anchor 12 is embedded is described as being shallower than the depth d of the sliding surface 5, but the second depth d ₂ is the depth d _2. And may be deeper than the depth d. If the second depth d ₂ is deeper than the depth d, but exhibits a certain degree of resistance in the same manner as the auxiliary anchor 12 also anchor 11, the resistance force acting in a direction to prevent the collapse of slope 1. As long as the second depth d ₂ is shallower than the first depth d ₁ , it is more economical to bury the auxiliary anchor 12 than to embed the anchor 11. The effect of the present invention is obtained that prevents destruction by an economical method.

  FIG. 3 is a diagram for explaining the action of the tension member in the first embodiment of the present invention. As shown in FIG. 3, in the slope reinforcing work 10 according to the present embodiment, when a force F that moves the soil mass in the vicinity of the auxiliary anchor 12 is applied, a tensile force T is applied to the tension member 13. As described above, the tensile force T transmits the resistance force of the anchor 11 against the collapse of the slope 1 to the auxiliary anchor 12, while a reaction force acts on the anchor 11. However, as described above, unless the slipping-through failure of the sliding layer 6 is taken into consideration, there are many cases where there is a margin in the resistance force of the anchor 11. 11 is stable.

As described above, in the first embodiment of the present invention, the auxiliary anchor 12 is disposed between the two anchors 11, and the auxiliary anchor 12 is connected to the anchor 11 using the tension member 13. Even if the installation interval of the anchor 11 is not narrowed, the effect of preventing the sliding layer 6 from slipping through can be enhanced. Since the second depth d ₂ of the auxiliary anchor 12 is buried shallower than the first depth d ₁ of the anchor 11 is embedded, construction of auxiliary anchor 12 is easier than the anchor 11, thus present It can be said that prevention of slip-through destruction by form is an economical method compared to the conventional one.

(Second Embodiment)
FIG. 4 is a schematic cross-sectional view of a slope reinforcement work according to the second embodiment of the present invention. As shown in FIG. 4, the slope reinforcement work 20 according to the present embodiment includes an anchor 11, an auxiliary anchor 22, and a tension member 13. In addition, since it is the same as that of said 1st Embodiment about structures other than the auxiliary anchor 22, the overlapping detailed description is abbreviate | omitted.

  At least one auxiliary anchor 22 is disposed between the two anchors 11 arranged in the y direction. The auxiliary anchor 22 is composed of a lock bolt, a steel pipe, a dimple pipe, or a deformed steel bar, like the auxiliary anchor 12 according to the first embodiment, but is different in that a hook shape is formed at the tip. Different from the first embodiment. The scissors shape is a shape in which the tip end portion 22A of the auxiliary anchor 22 directed toward the underground side is sharpened, the diameter is increased as the distance from the tip end increases, and a barb 22B is formed. In general, since the soil of a relatively shallow layer forming the sliding layer 6 of the slope 1 is soft, it may be possible to easily press-fit the auxiliary anchor 22 by sharpening the tip portion 22A. Although it is considered that there are few cases where the auxiliary anchor 22 needs to resist pulling out, the soil is introduced into the barb 22B, so that the adhesion to the clot is improved in the same way as the dimple tube shown in FIG. There is expected. In order to obtain the same effect, for example, a blade may be formed at the tip of the auxiliary anchor, or an opening may be provided.

(Third embodiment)
FIG. 5 is a schematic cross-sectional view of a slope reinforcing work according to the third embodiment of the present invention. As shown in FIG. 5, the slope reinforcing work 30 according to the present embodiment includes an anchor 11, an auxiliary anchor 32, and a tension member 13. In addition, since it is the same as that of said 1st Embodiment about structures other than the auxiliary anchor 32, the overlapping detailed description is abbreviate | omitted.

  At least one set of the auxiliary anchors 32 is disposed between the two anchors 11 arranged in the y direction. The auxiliary anchor 32 is composed of a rock bolt, a steel pipe, a dimple pipe, a deformed bar steel, or the like, similar to the auxiliary anchor 12 according to the first embodiment, but two that intersect each other when viewed from either direction. The auxiliary anchors 32A and 32B are different from the first embodiment in that they are provided in pairs. In the illustrated example, the auxiliary anchors 32A and 32B intersect each other when viewed from the x direction, but the auxiliary anchors 32A and 32B are arranged so as to intersect when viewed from other directions such as the y direction. Also good. When the auxiliary anchors 32A and 32B crossing each other sandwich the soil, it is expected that the adhesion to the soil mass is improved as in the dimple tube of the example shown in FIG. In order to obtain the same effect, for example, three or more auxiliary anchors may be arranged so as to cross each other. Further, this embodiment may be combined with the second embodiment described above, and a plurality of auxiliary anchors having a hook shape formed at the tip may be arranged so as to cross each other.

(Modification)
In the above description, the example in which the auxiliary anchor 12 (or the auxiliary anchor 22) is arranged between the two anchors 11 arranged in a direction intersecting at a substantially right angle with respect to the inclination direction of the slope has been described. For example, as in the example shown in FIG. 6A, the auxiliary anchor 12 is interposed between the two anchors 11 arranged in a direction intersecting at an angle not perpendicular to the inclination direction of the slope (the x direction in the figure). May be arranged. Accordingly, in the example of FIG. 6A, the anchor 11 is arranged at the apex of the triangular arrangement, and the auxiliary anchor 12 is arranged near the center of the side of the triangle. Further, as in the example shown in FIG. 6B, auxiliary anchors 12 may be arranged between three or more anchors 11 and connected to each anchor 11 using a tension member 13.

  As in the example shown in FIG. 7, when viewed along the inclination direction of the slope 1, the installation angles of the anchor 11 and the auxiliary anchor 12 may be different. In this case, the installation angle of the anchor 11 may be smaller than the installation angle of the auxiliary anchor 12. In the example of FIG. 7, the installation angle of the anchor 11 with respect to the slope 1 is α, whereas the installation angle of the auxiliary anchor 12 with respect to the slope 1 is β, and α <β. Moreover, although the case where the auxiliary anchor 12 is rod-shaped or plate-shaped has been described in the above example, a part or the whole of the auxiliary anchor 12 may have a tapered shape. Moreover, when installing the auxiliary anchor 12, you may take the reaction force with the anchor 11 and embed the auxiliary anchor 12 in the ground.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various variations and modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Slope, 5 ... Sliding surface, 6 ... Sliding layer, 7 ... Non-moving layer, 10, 20 ... Slope reinforcement work, 11 ... Anchor, 12, 22 ... Auxiliary anchor, 13 ... Tension member.

Claims (5)

At least two anchors arranged in a second direction intersecting the first direction on a slope inclined in a first direction and embedded in the slope to a first depth;
At least one auxiliary anchor disposed between the at least two anchors and embedded in the slope to a second depth shallower than the first depth;
A slope reinforcing work comprising: a tension member that connects the auxiliary anchor to the at least two anchors. The first depth is deeper than the depth of the slope of the slope,
The slope reinforcement work according to claim 1, wherein the second depth is shallower than the depth of the sliding surface.   The slope reinforcement work according to claim 1 or 2, wherein the at least two anchors and the auxiliary anchor are a steel pipe, a dimple pipe, or a deformed steel bar.   The slope reinforcement work according to any one of claims 1 to 3, wherein the auxiliary anchor has a hook shape at a tip.   The slope reinforcement work according to any one of claims 1 to 4, wherein the auxiliary anchor includes a plurality of auxiliary anchors that intersect with each other when viewed from any direction.

Images