JP5405939B2 - Inclined ground reinforcement structure and construction method - Google Patents

Description

  The present invention relates to an inclined ground reinforcing structure and method, and more particularly to an inclined ground reinforcing structure and method for reinforcing a sloped ground by installing a structure in the inclined ground.

  Landslides generally occur due to topographic conditions, ground stratification, groundwater conditions, and the like. In order to prevent such landslides, normally, as a measure to reinforce sloped ground, a suppression method that suppresses landslides by removing or mitigating factors such as groundwater that causes landslides, and driving structures into the ground Therefore, a deterrent construction method that suppresses landslide movement is adopted. For the former method, horizontal boring (see Patent Document 1) for drilling holes in the ground surface in the horizontal direction to construct drain holes, or drilling wells at locations where groundwater is concentrated, There are drainage wells that collect water (see Patent Document 1), etc., and in the latter method, pile driving (see Patent Document 2) that stops the landslide by driving a pile into the ground, and ground anchors on the ground A ground anchor construction (see Patent Document 3) that resists the sliding force of inclined ground by fixing is known.

Japanese Patent No. 11-158861 Japanese Patent No. 6-33464 Japanese Patent No. 2001-152459

  However, in the above conventional slope ground countermeasures (reinforcement structure and construction method), the range of the countermeasure effect of lowering the groundwater level or reinforcing the ground is limited, so the direction of sliding movement of the slope ground, It is difficult to cope with cases where groundwater needs to be lowered over a wide area and the ground needs to be reinforced, such as when the range cannot be predicted with high accuracy, or where there is a high possibility that the inclined ground will slide. In addition, as a method to reinforce the ground extensively, there is known a deep mixing treatment method in which solidified material such as cement and the ground are mixed by stirring to form a high strength improved ground. If the water permeability decreases, the water level on the back side of the improved ground rises and the ground becomes unstable or the groundwater withered downstream. Moreover, if only water permeability is to be secured, it is conceivable to continuously arrange materials with good water permeability, such as sand and crushed stone, in the form of grooves. No reinforcement. Furthermore, porous concrete is known as a material having water permeability and strength. However, porous concrete has less cement paste or mortar than ordinary concrete. Minutes are easily washed away, the strength becomes insufficient, and a solid body with high strength cannot be formed. Thus, it has been very difficult for conventional countermeasures to reduce groundwater over a wide area and reinforce the ground.

  The present invention solves such a conventional problem, and in this type of inclined ground reinforcement structure and construction method, when the sliding direction and range of the inclined ground cannot be accurately predicted, Even when it is necessary to reinforce a wide area of sloping ground, such as when there is a high possibility of slipping over a wide area, groundwater is discharged over a wide area on the sloping ground, effectively reducing the groundwater level. The purpose is to secure the stability of the sloped ground by suppressing the sliding motion over a wide area.

In order to achieve the above object, the present invention provides an inclined ground reinforcing structure in which an inclined ground is reinforced by installing a structure in the ground, and the structure is made of the material having water permeability and strength by the material having water permeability and strength. extending toward the downstream side in the panel from the upstream side of the water conducting, the upstream end surface, is formed in a wall shape that having a both side and a downstream side end face are installed, the strength of the structure, the slope plate Reinforce and collect the groundwater flowing down the water path of the sloped ground from the upstream end face and the both side faces of the structure into the structure by the water permeability of the structure, and pass through the structure by, you drained to a discharge destination from the downstream side end face of the structure, it is summarized in that.

The present invention is also embodied as follows.
(1) Porous concrete having underwater inseparability is adopted as a material having water permeability and strength.
(2) The structure penetrates the landslide layer and is fixed on the immovable ground below the sliding surface.
(3) The upstream end of the structure is opposed to the water channel in the sloped ground, and the downstream end is connected to a groundwater discharge means that extends to the groundwater discharge destination outside the sloped ground or extends to the groundwater discharge destination. Is done.
(4) A plurality of structures are installed in parallel on the inclined ground.
(5) An extension structure made of the same material as the structure is extended in a direction crossing the inclined ground from the upstream side at least with respect to the downstream end of the structure.

In order to achieve the above object, the present invention provides a slope ground reinforcement method for reinforcing a slope ground by installing the structure in the ground, and the structure includes porous concrete having underwater inseparability. a material having a water permeability and strength, extending toward the upstream side of the water conducting downstream in the inclined ground, the upstream side end face, and installed in the wall shape that having a both side and a downstream side end face, The slope ground is reinforced by the strength of the structure, and groundwater flowing down the water path of the slope ground is collected at the upstream end face and the both side faces of the structure by the water permeability of the structure. The gist is that the groundwater is discharged from the downstream end face of the structure to the groundwater discharge destination .
In this case, it is preferable to install in parallel multiple structures to tilt the ground.

According to the inclined ground reinforcing structure and construction method of the present invention, the structure for reinforcing the inclined ground is made of a material having water permeability and strength, such as porous concrete having non-separability in water. the soil in improving the extent necessary to prevent, extending from upstream to downstream of the water conducting, upstream end surface, formed in a wall shape that having a both side and a downstream side end surface is placed, The ground is reinforced by the strength of the structure, and groundwater that flows down the water path of the slope is collected from the upstream end face and both sides of the structure into the structure by the water permeability of the structure. Since the drainage is drained from the downstream end face of the structure to the discharge destination, if it is impossible to accurately predict the sliding direction and range of the inclined ground, there are a wide range of places where the inclined ground is likely to slide. Such as Even if extensive reinforcement measures of the swash ground is needed, the permeability effect of the structure, to drain extensively groundwater in the slope plate, it is possible to lower the groundwater level efficiently, the shear having the structure The sliding force over a wide area of the inclined ground can be suppressed by the resistance force, and the stability of the inclined ground can be reliably maintained.

The perspective view which shows the slope ground reinforcement structure in the 1st Embodiment of this invention Side sectional view of the reinforcing structure The top view which shows the slope ground reinforcement structure in the 2nd Embodiment of this invention Plan view showing an example of modification of the reinforcing structure

  Next, embodiments for carrying out the present invention will be described with reference to the drawings. 1 and 2 show a first embodiment. As shown in FIGS. 1 and 2, in the inclined ground reinforcing structure 1, a plurality of structures 11 are installed in the inclined ground 3 to reinforce the inclined ground 3.

  Each of the plurality of structures 11 is continuously formed in the inclined ground 3 by a material having water permeability and strength. As the material having water permeability and strength, porous concrete having water underseparability is adopted. In this case, in order to ensure the underwater inseparability and strength of the porous concrete, a high-performance water reducing agent and an underwater inseparable material are added to the porous concrete. The plurality of structures 11 made of porous concrete having an underwater inseparability are respectively improved areas necessary for preventing the drainage of the inclined ground 3 and sliding movement, in this case, the landslide layer at the end of the inclined ground 3. In (sliding block) 31, in the shape of a wall extending continuously from the upstream side to the downstream side of the water channel, in parallel with the direction crossing the inclined ground 3 or the direction orthogonal to the inclined direction of the inclined ground 3 Formed and installed. In this case, each structure 11 is embedded at the end of the inclined ground 3 (landslide layer 31) substantially along the inclined surface of the landslide layer 31, and the lower end of each structure 11 slips through the landslide layer 31. It reaches the stationary ground 33 below the surface 32 and is fixed in the stationary ground 33. The upstream end (surface) 12 of each structure 11 is opposed to the upstream of the water channel in the inclined ground 3, and the downstream end (surface) 13 is extended to the groundwater discharge destination outside the inclined ground 3. It should be noted that the improvement range, replacement rate, and strength of the inclined ground 3 by the reinforcing structure 1 are appropriately set by stable calculation by arc slip, similarly to the conventional ground improvement. Moreover, the space | interval between each structure 11 is suitably set from the fall amount of a groundwater level, prevention of slipping of the sliding soil lump between each structure, ensuring of intensity | strength required in order to stabilize the whole sliding soil lump, etc.

  Next, a method for constructing this reinforcing structure will be described with reference to FIG. In this construction method, a plurality of grooves 10 are excavated at locations where the structures 11 of the inclined ground 3 are installed, and the structures 11 are respectively installed in these grooves 10 to reinforce the inclined ground 3. Each of these grooves 10 has an improved range necessary for preventing drainage and sliding movement of the inclined ground 3, and in this case, at the end of the landslide layer (sliding soil block) 31 of the inclined ground 3, the direction crossing the inclined ground 3. Or it excavates in parallel in the direction orthogonal to the inclination direction of the inclined ground 3. Each groove 10 is excavated from the ground surface 30 through the landslide layer 31 to the fixed ground 33 below the sliding surface 32 at a predetermined position upstream of the water channel in the improved range of the landslide layer 31, and downstream from the predetermined position. It is gradually extended toward the side, and is formed into a substantially rectangular shape with a continuous horizontal section. Each of the plurality of structures 11 is continuously formed in the inclined ground 3 by a material having water permeability and strength. As the material having water permeability and strength, porous concrete having inseparability in water is used. In order to ensure underwater inseparability and strength of this porous concrete, an underwater inseparable material is added to the porous concrete. In this case, in order to ensure the flow value of cement paste or mortar, a high-performance water reducing agent is added together. The addition amount of the high-performance water reducing agent and the underwater non-separating material is appropriately set based on the flow value of the cement paste and the turbidity when dropped in water. (1) Mixing of cement and underwater non-separating material, (2) Mixing of water and high-performance water reducing agent, (3) 2 above It is preferable to perform the procedure of mixing cement paste with seeds and (4) mixing with cement paste charged with aggregate. Moreover, in order to prevent clogging of porous concrete, it is necessary to select appropriately the aggregate particle size and porosity of porous concrete. In this way, porous concrete has non-separability in water, so it can prevent the separation of cement during placement in groundwater and the outflow of cement due to groundwater after placement. In the following, it is possible to place on-site. Each time the excavation of each groove 10 proceeds on the inclined ground 3 by a predetermined length from a predetermined position on the upstream side of the water channel toward the downstream side, a sheet pile or a formwork is applied to the inner surface of each groove 10. Then, porous concrete having underwater inseparability is placed in each groove 10 to form a structure 11 in each groove 10. In this case, since porous concrete has many voids and cannot be pumped, a bucket or a belt conveyor is used for placing the porous concrete. In addition, by using a backhoe such as a telescopic clamshell type backhoe with a target depth of about 20 m and a slide arm type backhoe with a target depth of about 10 m in the construction of the structure 11, the arm extends and contracts. The work of excavating the groove 10 in the board 3 and the work of placing the porous concrete can be performed with the same machine, which is useful. After pouring concrete into each groove 10, a sheet pile or a formwork is extracted from each groove 10. Thus, each of the plurality of structures 11 made of porous concrete having inseparability in water is improved in order to prevent drainage and sliding movement of the inclined ground 3, in this case, a landslide layer (slip mass) ) It is formed at the end of 31 in the shape of a wall continuously extending from the upstream side to the downstream side of the water channel in parallel in the direction crossing the inclined ground 3 or in the direction perpendicular to the inclined direction of the inclined ground 3. Install.

  As a result of the plurality of structures 11 being embedded in the inclined ground 3 in this way, the groundwater flowing down the water path of the inclined ground 3 faces the water path due to the water permeability of each structure (porous concrete) 11. Water is collected from the upstream end face 12 of each structure 11 and from both side faces 14 into each structure 11, and passes through the structure 11 as a drainage path to downstream end face 13 of each structure 11. The water is drained to a discharge destination outside the sloped ground 3. Thereby, a wide range of groundwater on the inclined ground 3 is discharged to the discharge destination through the plurality of structures 11, and the groundwater level of the inclined ground 3 is efficiently lowered. Further, the landslide layer (slide mass) 31 is reinforced with high strength by each structure (porous concrete) 11 having high strength, and the shear resistance force by each structure 11 provides high stability against the slip failure of the inclined ground 3. Secured. In addition, since the strength of the structure 11 is several times that of a conventional caking method using a cement-based solidifying material, the improvement rate by the structure 11 is smaller than that of the conventional caking method.

  As described above, in the reinforcing structure 1 and the construction method, the plurality of structures 11 are formed on the sloped ground in the ground at the end of the sloped ground 3 by using a material having water permeability and strength (porous concrete having underwater inseparability). Since it is formed and installed in a wall shape extending continuously from the upstream side to the downstream side of the water channel in parallel with the direction crossing the board 3 or in the direction orthogonal to the inclination direction of the inclined ground 3, the inclined ground Even if it is necessary to take reinforcement measures in a wide area of the inclined ground 3, such as when it is impossible to accurately predict the direction and range of the sliding movement 3 or when there is a wide range of places where the inclined ground 3 is likely to slide, Due to the water permeability of the structure 11, the groundwater can be discharged in a wide range on the inclined ground 3, and the groundwater level can be lowered efficiently. Thus suppressing the sliding movement over the circumference, it can be kept reliably stable slopes board 3.

  Further, in this reinforcing structure 1, each structure 11 is arranged in a direction crossing the inclined ground 3 or in a direction perpendicular to the inclined direction of the inclined ground 3, particularly on the landslide layer (sliding mud) 31 of the inclined ground 3. In parallel, it is formed in a wall shape extending continuously from the upstream side to the downstream side of the water channel, and the upstream end surface 12 is opposed to the water channel in the inclined ground 3, and the downstream end surface 13 is outside the inclined ground 3. Therefore, it is possible to efficiently discharge a wide range of groundwater on the inclined ground 3 to the discharge destination through the plurality of structures 11, and to effectively reduce the groundwater level of the inclined ground 3.

  Further, in this reinforcing structure 1, each structure 11 is arranged in a direction crossing the inclined ground 3 or in a direction orthogonal to the inclined direction of the inclined ground 3, particularly on the landslide layer (sliding soil block) 31 of the inclined ground 3. In parallel, it is formed in a wall shape extending continuously from the upstream side to the downstream side of the water channel, and the lower end of each structure 11 passes through the landslide layer 31 and enters the immobile ground 33 below the sliding surface 32. Since it is fixed and installed, the strength of each structure (porous concrete) 11 can add a sufficient shear resistance to the landslide layer (sliding soil block) 31 and has high stability against slip failure of the inclined ground 3. Can be secured.

  In this embodiment, the downstream end 13 of each structure 11 is extended to the discharge destination of groundwater outside the inclined ground 3. However, the downstream end 13 of each structure 11 extends to the discharge destination of groundwater. Groundwater discharge means (drainage pipes, drainage channels, etc.) may be connected. In this embodiment, a plurality of structures 11 are installed in parallel on the inclined ground 3. However, for example, if the width of the inclined ground 3 is relatively narrow, one structure 11 may be installed. Even if it does in this way, the effect similar to the said 1st Embodiment can be acquired.

  FIG. 3 shows a second embodiment of the present invention. As shown in FIG. 3, in the inclined ground reinforcing structure 2, the extended ground structure 21 is installed together with the plurality of structures 11 in the inclined ground 3 to reinforce the inclined ground 3. In this case, since the plurality of structures 11 have already been described, only the extension structure 21 is denoted by a new reference numeral and description is added here. The extension structure 21 is installed by the same method using the same material as each structure 11. The extended structure 21 is at least upstream from the downstream end 13 of each structure 11, in this case, in a direction crossing the inclined ground 3 from the upstream end 12 of each structure 11 and each structure 11. Is extended in a direction substantially perpendicular to the direction.

  In this way, the extension structure 21 is horizontally installed and installed in the inclined ground 3, so that the groundwater flowing down the water path of the inclined ground 3 is caused by the water permeability of the extension structure (porous concrete) 21. Water is collected into the extension structure 21 from the upstream side surface 22 of the extension structure 21. And this groundwater is guide | induced to each structure 11 through the extended structure 21, and is drained through the structure 11 from the downstream end 13 of each structure 11 to the discharge | emission destination out of the inclined ground 3. Accordingly, a wide range of groundwater on the inclined ground 3 is collected by the extension structure 21 and discharged to the discharge destination through each structure 11, so that the groundwater level of the inclined ground 3 is more efficiently lowered. Further, the inclined ground 3 is reinforced with higher strength due to the strength of the extended structure 21 and each structure 11, and high stability against slip failure of the inclined ground 3 due to the shear resistance force by the extended structure 21 and each structure 11. Sex is secured.

  In this way, the extension structure 21 is provided from the upstream side with respect to at least the downstream end 13 of each structure 11, in this case, in the direction crossing the inclined ground 3 from the upstream end 12 of each structure 11. Since it extended in the direction orthogonal to the structure 11, when the direction and range of the sliding movement of the inclined ground 3 cannot be accurately predicted, when the place where the inclined ground 3 is likely to slide covers a wide range, etc. Even when reinforcement measures are required over a wide area of the inclined ground 3, the groundwater level can be more efficiently lowered by discharging the groundwater more extensively in the inclined ground 3 by the extended structure 21 and each structure 11. In addition, a wider range of sliding motion of the inclined ground 3 can be suppressed.

  In the second embodiment, the extension structure 21 is extended from the upstream end 12 of each structure 11 in a direction crossing the inclined ground 3 and in a direction substantially orthogonal to each structure 11. However, the extension structure 21 may be extended from the upstream side in the direction crossing the inclined ground 3 with respect to at least the downstream end of each structure 11, for example, as shown in FIG. Is extended in a direction crossing the inclined ground 3 from the upstream end 12 of each structure 11 and further in a direction crossing the inclined ground 3 between the upstream end 12 and the downstream end 13 of each structure 11. May be. In addition, when one structure is installed on the inclined ground, and this structure is provided with an extended structure, the extended structure is arranged in a direction crossing the inclined ground from the upstream side with respect to at least the downstream end of the structure. In this case, the entire structure is substantially T-shaped or substantially cross-shaped in plan view. Even if it does in this way, the effect similar to 2nd Embodiment can be acquired.

  As described above, in the first and second embodiments, in particular, the point of reinforcing the landslide mass and securing its stability has been described. However, this reinforcing structure and construction method can be used to cut earth and sand ground, existing embankment, It can be applied to reinforcement of embankments and embankments of cliff mass deposits to ensure its stability. In applying this reinforcing structure and method, it is preferable to set the cut slope as an improvement range when reinforcing a cut portion with a slope that cannot be secured under the current conditions. When reinforcing a river embankment or the like, it is preferable to make the butt and small steps the improvement range. In the case of reinforcing the embankment on the reclaimed embankment and the cliff mass deposit in the swamp, it is preferable to improve the range including the foundation ground.

1 Inclined ground reinforcement structure 10 Groove 11 Structure 12 Upstream end (surface)
13 Downstream end (surface)
14 Side surface 2 Inclined ground reinforcement structure 21 Extension structure 22 Upstream side surface 3 Inclined ground 30 Ground surface 31 Landslide layer (slide mass)
32 slip surface 33 immovable ground

Claims (8)

In the inclined ground reinforcement structure where the inclined ground is reinforced by installing a structure in the ground,
The structure is of a material having a water permeability and strength, formed on the extending from the upstream side of the water conducting in inclined ground toward the downstream side, the upstream side end face, the wall-like that having a both side and a downstream side end surface is installed is,
While reinforcing the inclined ground by the strength of the structure,
Due to the water permeability of the structure, groundwater flowing down the water channel of the inclined ground is collected into the structure from the upstream end surface and the both side surfaces of the structure, and the structure is passed through, effluent from the downstream side end surface of the structure to the output tray,
An inclined ground reinforcement structure characterized by that.   The slope ground reinforcement structure according to claim 1, wherein porous concrete having underwater inseparability is adopted as a material having water permeability and strength.   The inclined ground reinforcing structure according to claim 1 or 2, wherein the structure penetrates the landslide layer and is fixed to the stationary ground below the sliding surface.   The upstream end of the structure is opposed to a water channel in the inclined ground, and the downstream end is extended to a groundwater discharge destination outside the inclined ground, or connected to groundwater discharge means extending to the groundwater discharge destination. Item 4. The inclined ground reinforcing structure according to any one of Items 1 to 3.   The inclined ground reinforcement structure according to any one of claims 1 to 4, wherein a plurality of structures are installed in parallel on the inclined ground.   The sloped ground reinforcement according to any one of claims 1 to 5, wherein an extended structure made of the same material as the structure is extended in a direction crossing the sloped ground from an upstream side at least with respect to a downstream end of the structure. Construction. In the slope ground reinforcement method for reinforcing the slope ground by installing a structure in the ground,
The structure is extended from the upstream side to the downstream side of the water channel into the inclined ground by a material having water permeability and strength including porous concrete having inseparability in water, and has an upstream end face, both side faces, and a downstream face. installed is formed in a wall shape that having a side end surface,
While reinforcing the inclined ground by the strength of the structure,
Due to the water permeability of the structure, groundwater flowing down the water path of the inclined ground is collected at the upstream end face and the both side faces of the structure, and discharged from the downstream end face of the structure to a groundwater discharge destination. To
The slope ground reinforcement method characterized by this. The slope ground reinforcement method according to claim 7, wherein a plurality of structures are installed in parallel on the slope ground .

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