JP3749459B2 - Slope stabilization method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a slope stabilization method, and more particularly to a slope stabilization method suitable for stabilizing a natural slope.
[0002]
[Prior art]
Conventionally, as a method of stabilizing natural slopes, reinforcing materials such as reinforcing steel reinforced earth (rock bolt construction) have a regular separation distance from the ground surface (moving layer) of the natural slope to the ground (immobility). A method is known in which the outer periphery of the reinforcing material is grouted by being inserted substantially horizontally or slightly downward in the layer).
[0003]
In this conventional slope stabilization method, the slip force of the moving layer is resisted by the shearing / bending of the inserted reinforcement and the peripheral frictional force with the surrounding ground, thereby stabilizing the slope. Yes.
[0004]
[Problems to be solved by the invention]
However, in the conventional slope stabilization method, since the reinforcing material is regularly arranged in the ground with a constant separation distance, when the moving layer slides, the same behavior is observed throughout the moving layer. Present. That is, the conventional slope stabilization method has a structure in which the sliding force is received by the strength (shear and bending) of the reinforcing material itself. Therefore, if the material of the reinforcing material is weak or the total number is small, the slope is stabilized. There was a problem that there was a possibility that it could not be maintained sufficiently.
[0005]
This invention is made | formed in view of such a problem, Comprising: It aims at providing the slope stabilization construction method which can aim at stabilization of a slope still more effectively.
[0006]
[Means for Solving the Problems]
Usually, on natural slopes, a soft layer with weak shear resistance (slip strength) is interposed between the immovable layer, which is the base rock, and the moving layer, which is collapsed sediment, due to the influence of groundwater flow. When the ground becomes soft, it tends to promote landslides. On the other hand, the moving layer on the soft layer has a relatively strong shear resistance compared to the soft layer. Therefore, on this type of natural slope that is prone to landslides, the sliding block is divided so that the ratio of the moving layer part with larger shear resistance compared to the soft layer increases, and multiple blocks with different sliding forms on the natural slope are separated. By providing, it is thought that stabilization of a slope can be aimed at more effectively.
[0007]
The present invention has been made paying attention to such points, and the slope stabilization method according to the present invention suppresses a landslide on a natural slope in which a soft layer is interposed between a non-moving layer and a moving layer. A slope stabilization method for forming a pair of resistors, a plurality of resistors being arranged substantially parallel to the sliding direction of the natural slope, and being surrounded by the plurality of resistors Is a first sliding block, and each region on the natural slope divided by the first sliding block is a second sliding block, and the first sliding block and the second sliding block The sliding form is made different from each other to enhance the shear resistance of the natural slope.
[0008]
The slope stabilization method of the present invention is characterized in that the shear resistance of the first sliding block is larger than the shear resistance of the second sliding block.
[0009]
According to the slope stabilization method described above, the sliding forms of the first sliding block and the second sliding block are mutually adjusted so that the shear resistance of the first sliding block is larger than the shear resistance of the second sliding block. Therefore, the shear resistance of the first sliding block is increased to improve the sliding resistance, and the second sliding block is further improved by the frictional resistance at the boundary between the first sliding block and the second sliding block. The sliding resistance is also improved, which improves the stability of the entire slope.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings.
[0011]
FIG. 1 is a perspective view schematically showing an example of a natural slope, which is caused by groundwater flow between a base rock (immobilized layer) 1 and a collapsed sediment layer (moving layer) 3. Thus, the soft layer 4 generated is interposed, and the upper surface of the collapsed sediment layer 3 forms the ground surface 2. And the A part shows the collapse range which consists of the moving soil blocks 5 in the collapsible sediment layer 3 in the figure, and the natural slope has a soil structure that is easy to slide in the direction of arrow B. Further, when the slope collapses, the soft layer 4 forms a main slip surface.
[0012]
FIG. 2 is a perspective view schematically showing an embodiment of the slope stabilization method of the present invention. In this embodiment, a plurality of first sliding blocks 7 a to 7 c are formed on the moving soil mass 5. Thus, the moving soil block 5 is divided into a plurality of second sliding blocks 8a to 8e by the first sliding block 7a.
[0013]
Specifically, in the first sliding blocks 7a to 7c, a plurality of resistor bodies (two pairs in the present embodiment) are arranged substantially in parallel with the sliding direction of the moving earth block 5 with the pair of resistor bodies 6 as one set. And is surrounded by the plurality of sets of resistors 6.
[0014]
As shown in FIG. 3, the resistor 6 includes a substantially square head plate 9 and a PC steel strand 10 whose base end is fixed to a substantially central portion of the head plate 9. The plate 9 is placed on the ground surface 2 and the PC steel strand 10 penetrates the collapsible sediment layer 3 and the soft layer 4, the tip of which is inserted into the base rock 1 and the outer peripheral part 11 is grouted. Is fixed.
[0015]
When the moving mass 5 collapses on the slope, shear failure occurs on the continuous slip surface, that is, the slip surface 12 in the soft layer and the slip surface 13 in the collapsed sediment layer.
[0016]
However, in the first sliding block 7a, since the ratio of the collapsed sediment layer 3 that is stronger than the soft layer 4 is increased as compared with the case where the resistor 6 is not provided, the shear resistance is increased. The sliding block 7a is difficult to slide even if heavy rain occurs.
[0017]
In addition, since frictional resistance is generated at the boundary between the first sliding block 7a and the second sliding blocks 8a and 8b, the shear resistance of the second sliding blocks 8a and 8b is increased, and therefore no resistor is provided. Compared to the case (FIG. 1), the average shear resistance of the entire moving mass 5 is increased, and as a result, the slidability of the slope is lowered and the slope is stabilized.
[0018]
【The invention's effect】
As described above in detail, the slope stabilization method according to the present invention is a slope stabilization method for suppressing a landslide on a natural slope in which a soft layer is interposed between a non-moving layer and a moving layer. A plurality of sets of resistors are arranged substantially in parallel with the sliding direction of the natural slope, and a narrow region surrounded by the plurality of sets of resistors is used as a first sliding block. Each area on the natural slope divided by one sliding block is defined as a second sliding block, and the sliding form of the first sliding block and the second sliding block is made different from each other to shear the natural slope. Since the resistance is strengthened, the first sliding block has a higher shear resistance due to an increase in the ratio of the moving layer having a higher strength than the soft layer, and the first sliding block 7a slides even if heavy rain occurs. It becomes difficult. In addition, since frictional resistance is generated at the boundary between the first sliding block and the second sliding block, the shear resistance of the second sliding block is also increased, and thus the average shear resistance of the entire moving layer is increased. As a result, the slidability of the slope is reduced and the slope is stabilized.
[0019]
Many natural slopes remain stable over a long period of time, and in order to achieve further stabilization against temporary instability such as heavy rain, it is only necessary to give a slight increase in strength. Stabilization of the slope can be easily realized by making the ratio of the sliding surface passing through the layer relatively small and utilizing the strength in the collapsible sediment layer having a relatively large strength.
[0020]
In addition, the resistor is not used to suppress the sliding force of the moving layer, but is used for the purpose of dividing the moving layer. Construction costs can also be greatly reduced.
[0021]
In addition, since the present invention realizes stabilization of the natural slope by increasing the shear resistance of the first sliding block, it does not directly handle the sliding force due to landslides compared to ground anchor work and deterrent pile work, Therefore, there is little influence on the aging of the material without being constantly subjected to large earth pressure.
[Brief description of the drawings]
FIG. 1 is a perspective view schematically showing an example of a natural slope.
FIG. 2 is a perspective view schematically showing an embodiment of a slope stabilization method according to the present invention.
3 is a cross-sectional view taken along line XX in FIG.
[Explanation of symbols]
1 Base rock (Fudo layer)
3 Collapsed sediment layer (moving layer)
4 Soft layer 5 Moving mass 6 Resistors 7a to 7c First sliding blocks 8a to 8e Second sliding block 9 Head plate 10 PC steel strand

Claims (2)

A slope stabilization method for suppressing landslides on natural slopes where a soft layer is interposed between the immovable layer and the moving layer,
A pair of resistors as a set and a plurality of sets of resistors are arranged substantially parallel to the sliding direction of the natural slope, and a narrow region surrounded by the plurality of sets of resistors is a first sliding block, Each area on the natural slope divided by the first slide block is defined as a second slide block, and the slide forms of the first slide block and the second slide block are made different from each other, thereby the natural slope. Slope stabilization method characterized by strengthening shear resistance of steel. 2. The slope stabilization method according to claim 1, wherein the shear resistance of the first sliding block is larger than the shear resistance of the second sliding block.

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