JPH0633464A - Landslide preventive structure - Google Patents

Abstract

PURPOSE:To obtain a landslide preventive structure capable of allowing each preventive pile to receive sliding load equally and integrally, which comprises a large number of preventive piles logically and economically. CONSTITUTION:A plurality of preventive piles 11 are installed in such a fashion that they may project to the upstream side in a sliding direction X while the pile head of each restraint pile is integrally connected to each other by means of an arch-shaped connection member 12. The connection member 12 comprises a fixture 17 built up along an arc-shaped alignment of the preventive piles and a load support 18 which projects to the downstream side of the sliding direction X from the fixture 17 and has a specified cross sectional area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a landslide prevention structure, and more particularly to a landslide prevention structure composed of a large number of suppression piles driven from the ground surface through a landslide surface.

[0002]

2. Description of the Related Art Generally, landslide refers to a phenomenon in which a part of land is slipped due to groundwater or the like, or is moved with it, and a portion of the soil with weak shear resistance is used as a landslide surface.
The earth mass on the top slides along this.

As a method for preventing such a landslide, conventionally, a control method for preventing the landslide by changing the natural phenomenon of the place where the landslide occurs, that is, by removing or reducing factors such as groundwater that cause the landslide. When,
The deterrent construction method that stops the landslide movement by the deterrent force of the structure itself such as the pile body driven by the pile driving or the shafting driven into the ground is mainly adopted.

As one example of the above-mentioned deterrent construction method, there is known a landslide deterrent structure composed of a large number of piles driven from the ground surface through the landslide surface, that is, a large number of deterring piles. As shown in FIG. 4, this conventional restraint structure 20 has a large number of restraint piles 21 arranged linearly in one or more rows in a direction perpendicular to the landslide direction X. , The pile heads are integrated by a connecting portion 22 having a truss structure or the like.

[0005]

However, in such a conventional landslide restraining structure using restraining piles, since the sliding load is generally large in the central portion where the sliding depth is the largest, the load of the piles arranged in the central portion is increased. As the load becomes larger, the load carried by each pile becomes unbalanced, and therefore a large number of restraining piles cannot efficiently and evenly support the landslide load as an integrated structure, and the structure becomes larger than necessary. There was a problem.

Further, since each restraint pile is a cantilever supported by the ground below the sliding surface, there is a problem that a large rigidity is required, and in order to cope with this, the load is supported even at the upper end of the restraint pile. You can think of a way to
The method of connecting the pile heads with a truss structure or the like does not have the strength to support the upper end of the restraining pile against the tensile load generated on the downstream side of the connecting portion, and the upper end of the restraining pile is anchored by an anchor. In the method of supporting, since the landslide surface generally has a gentle inclination, it is difficult to use an anchor together, and therefore, there is a problem that the rigidity of the restraining pile cannot be reduced by either method.

Therefore, the present invention has been made in order to solve the above-mentioned problems, and in a landslide prevention structure by a restraint pile, a large number of restraint piles can uniformly take a sliding load uniformly and reasonably. The purpose is to provide an economical landslide prevention structure.

It is another object of the present invention to provide a landslide prevention structure capable of reducing the rigidity of the suppression pile and reducing its scale by firmly supporting the upper end of the suppression pile.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above object, and its gist is to provide a landslide prevention structure comprising a large number of suppression piles driven from the ground surface through a landslide surface. A landslide prevention structure is characterized in that a large number of restraint piles are arranged in an arch shape projecting upstream with respect to the landslide direction and the pile heads are integrally connected by an arch-shaped connecting member.

The term "suppressing pile" as used herein means a pillar body such as a steel pipe pile or a concrete pile driven into the ground by pile driving or shafting, or a rod-shaped member such as a reinforced steel rod or a steel pipe. Say. The arch-shaped connecting member can be constructed, for example, by rolling the concrete into an arch shape by winding the pile head, but a preformed arch-shaped steel member or the like is attached to the pile head. You may form by this.

Further, in the landslide restraining structure of the present invention, the connecting member is formed with a fixing portion formed along the arch-shaped arrangement line of the plurality of restraining piles, and a downstream side from the fixing portion in the landslide direction. In addition, it is preferable that the load supporting portion protrudes in an arch shape so as to have a predetermined cross-sectional area and supports the landslide load on the restraining pile as a compressive force.
Here, the predetermined cross-sectional area is appropriately designed in consideration of the landslide load, the radius of curvature of the arch shape, the number of the restraining piles, and the like in accordance with the compression load to be undertaken.

[0012]

In the landslide restraint structure of the present invention having the above-mentioned structure, a large number of restraint piles, which are arranged continuously in an arch shape and integrally connected to the pile heads, are integrated so that each pile exerts a mutual force. It can form a structure and evenly bear the landslide load.

Further, the arch-shaped connecting member reduces the rigidity of the restraining pile by supporting the landslide load as a compressive load even at the upper end portion of the restraining pile due to its arch effect. Further, if the connecting member is provided with a load supporting portion projecting from the fixing portion and having a predetermined cross-sectional area, it is possible to more firmly support the landslide load and further simplify the scale of the restraining pile.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

The landslide prevention structure 10 of this embodiment is shown in FIG.
As shown in FIG. 11, a large number of restraint piles 11 are constructed to restrain the landslide in the X direction in the landslide range A, and are continuously laid at predetermined intervals in an arch shape protruding toward the upstream side in the X direction. And an arch-shaped connecting member 12 that integrally connects the pile heads of the restraining pile 11.
The restraint piles 11 are, for example, steel pipe piles that are driven into the ground by various pile driving methods, and include large-scale piles 15 located at both ends of the arch-shaped restraint structure 10 and small-scale piles 16 located between them. Two types are used. The large-scale pile 15 has a diameter several times as large as that of the small-scale pile 16, is placed outside the landslide range A, and is sufficient to handle the reaction force transmitted through the arch-shaped connecting member 12. It has sufficient strength and rigidity. On the other hand, in the landslide range A, the small-scale pile 16 penetrates the landslide surface C from the ground surface B to reach the ground 14 therebelow as shown in FIG. Supports the landslide load.

As shown in FIGS. 1 and 3, the upper end of the restraining pile 11, that is, the pile head, has an arch-shaped connecting member 1 as shown in FIGS.
The two are integrally connected. Arched connecting material 12
Is involved in the pile head of the small pile 16 and the large pile 1
It is constructed in arch shape by pouring concrete integrally with 5. Then, the connecting member 12 projects to the downstream side in the landslide direction X from the fixing portion 17 having a small wall thickness, which is constructed along the arch-shaped disposition line of the small-scale piles 16 that are continuously driven. Load support 18 with large wall thickness
It is composed of and. The fixed portion 17 is the restraint pile 11
Has the function of fixing in a state of being integrally connected in an arch shape,
On the other hand, the load support portion 18 has a function of supporting the landslide load applied to the small-scale pile 16 as a compression load due to the arch effect and transmitting this to the large-scale piles 15 at both ends. In addition, the load supporting portion 18 is provided with a necessary cross-sectional area corresponding to the compressive load that is appropriately designed in consideration of the compressive load to be handled, that is, the design landslide load, the radius of curvature of the arch shape, the number of the restraining piles 11, and the like. Sectional shapes such as width and height are determined.

In the landslide prevention structure 10 of the present embodiment having the above structure, the small-scale pile 16 has the lower end portion at the lower ground 1
Not only is it fixed to No. 4 to support the landslide load, but its upper end is integrally connected in an arch shape by the connecting member 12, so that the upper end is also supported by the arch effect of the connecting member 12. Further, the respective restraint piles 11 exert a mutual force via the connecting member 12, so that the respective restraint piles 11 evenly support the landslide load.

[0018]

As described in detail above, in the landslide restraining structure of the present invention, a large number of restraining piles are arranged in an arch shape projecting upstream with respect to the landslide direction, and the pile heads are arched. Since a large number of restraint piles are integrally and evenly loaded by the joints, the restraint piles can be made small in size or the number of piles can be reduced, which is rational and economical. It makes it possible to construct a landslide prevention structure. Further, by supporting the landslide load even at the upper end portion of the restraint pile by the arch effect of the connecting member, the rigidity of the restraint pile can be reduced, so that the landslide restraint structure can be constructed more economically.

[Brief description of drawings]

FIG. 1A is an explanatory diagram showing a configuration of a landslide prevention structure according to the present invention. (B) is an enlarged view of a portion D of (A).

FIG. 2 is a cross-sectional view taken along line YY of FIG.

FIG. 3 is a cutaway perspective view showing a structure of a connecting member.

FIG. 4 is an explanatory diagram of a conventional landslide prevention structure including a large number of prevention piles.

[Explanation of symbols]

 10 Landslide Inhibiting Structure 11 Inhibiting Pile 12 Connecting Material 17 Fixed Part 18 Load Supporting Part X Landslide Direction

Claims (2)

[Claims] 1. A landslide prevention structure comprising a plurality of restraint piles driven from the surface of the earth through a landslide surface, wherein the plurality of restraint piles are arranged in an arch shape projecting upstream with respect to the landslide direction, A landslide prevention structure characterized by integrally connecting the pile heads with an arch-shaped connecting material. 2. The fixing member, wherein the connecting member is formed along an arch-shaped disposition line of the plurality of restraint piles, and is arch-shaped and has a predetermined shape on the downstream side in the landslide direction from the fixing portion. The landslide prevention structure according to claim 1, further comprising: a load supporting portion that protrudes so as to have a cross-sectional area and that supports a landslide load applied to the suppression pile as a compressive force.