JP6765680B2 - Block assembly type sabo dam - Google Patents

Description

The present invention relates to a block assembly type sabo dam capable of accurate stable calculation while realizing rapid construction by a simple method.

A gravity-type sabo dam, in which the skeleton of the dam body is constructed of cast-in-place concrete, is widely known as a countermeasure facility for debris flow and lahar, but the construction period is prolonged and there is a problem with responsiveness.
On the other hand, a block-assembled sabo dam has been proposed as a countermeasure facility when rapid construction is required (Patent Documents 1 and 2).
As a block assembly type sabo dam, a rectangular parallelepiped block is manufactured in advance at the factory, and it has a dam structure in which multiple blocks brought to the site in an emergency are simply stacked, and has multiple through holes in the vertical direction. A dam structure is known in which blocks are stacked and rigid piles such as concrete-filled steel pipes are vertically inserted across through holes of a plurality of blocks to position a plurality of blocks.

JP-A-9-228348 Japanese Unexamined Patent Publication No. 2000-290969

Conventional sabo dams have the following problems.
<1> In a gravity-type sabo dam in which the skeleton of the dam body is constructed of cast-in-place concrete, the dam body is an integral structure, so it is possible to design based on the established stability calculation method.
On the other hand, in the block assembly type sabo dam, although multiple block groups are positioned on the rigid piles, each block is moored on the rigid piles and separated so that they can slide individually. ..
Therefore, the stability calculation method for gravity dams cannot be applied to conventional block-assembled sabo dams, and there is no established calculation method.
<2> Especially when designing a sabo dam, it is necessary to take into consideration unexpected times, but the mechanical properties at the joint between blocks against an unexpected flow-down load have not been fully elucidated.
This makes it more difficult to calculate the stability of block-assembled sabo dams.
<3> Patent Document 2 discloses that when each block individually shifts and moves when a debris flow occurs, the load of the flowing object is absorbed by the bending toughness of the rigid pile.
The sabo dam described in Patent Document 2 uses a high toughness concrete-filled steel pipe in which high PC steel material is embedded as a rigid pile, and the cost of the rigid pile is high and a large weight rigid pile is handled on site. It has problems such as troublesomeness.
<4> In this way, while the established stability calculation method can be applied to the conventional gravity-type sabo dam, the construction period is prolonged and there is a problem with responsiveness, while the other block assembly-type sabo dam has a construction period. However, there is a problem that there is no established stable calculation method.
With the recent large-scale earthquakes and torrential rains, it is expected that the occurrence of large-scale landslides and debris flows will continue to increase, and now stable calculations are possible and the construction period can be significantly shortened. Proposals for dams are desired.

The present invention has been made in view of the above points, and the purpose of the present invention is to provide a block assembly type sabo dam to which an established stable calculation method can be applied and which can be quickly constructed by simple construction. To provide.

The present invention is a gravity-type sabo dam in which a plurality of block block walls are stacked.
The block block wall is an aggregate composed of a plurality of single blocks and a connecting member arranged so as to penetrate between the plurality of single blocks in the vertical direction, and the plurality of single blocks are formed as an integral structure via the connecting member. It is formed.
Shear columns that function as shear keys when receiving an attack are vertically arranged between the horizontal joints of the block block walls that are adjacent to each other.
A plurality of through holes into which a connecting member and a shear column can be inserted vertically are formed in each single block at equal intervals.
A gap is formed between the through hole and the peripheral surface of the shear column located across the joint portion of the block block wall, and the block block wall can slide through this gap.
As the shear column, a steel material that can be sheared and deformed at the time of receiving an impact, or various members can be used.
The shear column may be a column divided into a plurality of columns along the height direction of the dam body, or may be a single continuous column.
The planar shape of the single block is not particularly limited and may be polygonal.
A plurality of through holes are formed at equal intervals on the plate surface of the single block so that the through holes are aligned on the same vertical line when the single blocks are stacked in a staggered pattern.
One or more through holes for water passage may be formed laterally through the block block wall so that sand can be discharged through the through holes.

The present invention has at least one of the following effects by having the above configuration.
<1> A block block wall assembled by integrating a plurality of single blocks can be handled as an integral structure.
Therefore, while assembling multiple single blocks, it is possible to apply the stability calculation method for gravity dams, and it is also possible to realize rapid construction, simultaneously achieving two issues that have been difficult to achieve. be able to.
<2> The shear columns arranged so as to straddle the joints of the block block walls adjacent to the top and bottom function as a shear key, not as a resistance member against bending deformation.
Therefore, not only is it economical to use inexpensive and lightweight steel as the material for the shear column as it is, but it is also easy to handle on site.
<3> Since a gap is formed between the through hole of the block block wall and the peripheral surface of the shear column, it is allowed to slide in a certain range of the block block wall at the time of receiving, the load of the flowing object is relaxed, and the flow flows down. It can absorb the energy of things.
<4> After allowing a certain range of sliding of the block block wall, the shear column functions as a resistance member due to the toughness deformation of the crush, so even if an unexpected flow-down object load acts, the large deformation of the shear column is effective. Can be prevented.
<5> Since the sabo dam has a structure in which a plurality of single blocks are stacked in a staggered manner, the independence of the block block wall is not impaired even if some of the single blocks are pulled out and assembled.
Therefore, even though it is a block-assembled sabo dam, it is possible to open a through hole for water passage at an arbitrary position on the dam frame.

Overall perspective view of the block assembly type sabo dam according to the present invention. Sectional view of II-II in FIG. Perspective view of the block block wall with a part omitted Explanatory drawing of construction method of block assembly type sabo dam Explanatory drawing of stable calculation example of block assembly type sabo dam Explanatory drawing of an unexpected design example of a block assembly type sabo dam Model illustration of shear column collapse Explanatory drawing of another block assembly type sabo dam with a through hole in the dam frame

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<1> Outline of Sabo Dam Explaining with reference to FIGS. 1 and 2, the block assembly type Sabo dam 10 (hereinafter referred to as “Sabo dam 10”) is constructed by a block assembly type, but the final structure is a gravity type. a check dams, a plurality of blocks Katamarikabe ₂₀ stacked multiple stages to build on-site (20 _1, 20 2, ₂₀ 3, ...), longitudinally joints of blocks Katamarikabe 20 vertically adjacent It is provided with a shear column 30 which is positioned so as to penetrate through.

<2> block Katamarikabe block Katamarikabe ₂₀ (20 _1, 20 2, ₂₀ 3, ...) are divided dam obtained by dividing the check dam 10 at a plurality of horizontal component section.
Explaining with reference to FIGS. 2 and 3, each block block wall 20 is integrated with an aggregate of a plurality of single blocks 21 stacked side by side in the vertical and horizontal directions and through the plurality of single blocks 21 in the vertical direction. It is composed of a connecting member 25.
The upper and lower surfaces of the block block wall 20 are continuously formed in the horizontal direction, and when a plurality of block block walls 20 are stacked, the horizontal joint surface becomes a joint portion.

<2.1> Single block The single block 21 is a rectangular parallelepiped made of concrete formed to a certain thickness, and its planar shape is a polygon including a square, and two or more penetrating the plate surface at equal intervals. The holes 22 are arranged side by side.

Explaining the two types of single blocks 21 and 23 illustrated in FIG. 3, the single block 21 having a square plane shape has four through holes 22 formed in the vertical direction.
The other single block 23, which is obtained by dividing the single block 21 into a rectangular shape, has two through holes 22 formed in the vertical direction.
The forming intervals of the through holes 22 of the two single blocks 21 and 23 are both in the same dimensional relationship.
The through holes 22 are formed at equal intervals so that the upper and lower through holes 22 are aligned on the same vertical line when different types of single blocks 21 and 23 are stacked.

<2.2> Connecting member The connecting member 25 is a connecting member for structurally integrating a plurality of single blocks 21 and 23 constituting each block block wall 20 through a plurality of aligned through holes 22. ..
Since the connecting member 25 is for integrating the block block wall 20 as a unit, its total length does not exceed the height of the block block wall 20.
In other words, the connecting member 25 also functions as a shear resistance member between the plurality of assembled single blocks 21 and 23, but is expected to function as a shear resistance member at the joints of the vertically adjacent block block walls 20. Absent.

<2.3> Example of connecting material As the connecting material 25 that integrates a plurality of single blocks 21 and 23 through a plurality of aligned through holes 22, for example, a binder such as mortar, concrete, or hard resin is applied. In addition to what can be done, a combination of a hollow tube having a diameter smaller than that of the through hole 22 and a binder filled between the hollow tube and the peripheral surface of the hole wall may be used.
Further, a PC steel material may be used to rigidly connect the plurality of single blocks 21 and 23.
The connecting member 25 may be a member that can be integrated with the single blocks 21 and 23 constituting the block block wall 20 with a connecting force that does not disperse when a flow-down object load is applied.

<3> Shear column The shear column 30 functions as a shear key (shear resistance member) at the time of receiving a shock, and does not have a connecting function for integrating a plurality of single blocks 21 and 23 like the connecting member 25 described above. ..
The shear column 30 has a length that can be arranged so as to straddle between the joint portions of the block block walls 20 that are vertically adjacent to each other.
The shear column 30 is expected to absorb energy due to "crushing" of the shear column 30 along the shear direction after suppressing excessive sliding of the block block wall 20 as a shear key, and absorbs energy due to bending deformation. Not what you expect.

<3.1> Example of Shear Column The shear column 30 may be a member that functions as a shear resistance member at the joint portion of the block block wall 20 adjacent to the top and bottom, and examples thereof include hollow steel materials, but the cost, weight, and the like. Steel pipes are preferable because they are excellent in handleability.
The shear column 30 is not limited to a hollow structure, and may be a solid structure capable of shear deformation.

<3.2> Overall length of shear column The shear column 30 may be a single continuous column, but a shear column 30 divided into a plurality of columns as in this example may be used.
In the case of the divided form, a plurality of shear columns 30 are arranged in the vertical direction, but the joint position of the shear columns 30 is shifted in the height direction with respect to the joint position of the block block wall 20.
This is because if the joint position of the block block wall 20 and the joint position of the shear column 30 are the same, the shear column 30 does not function as a shear key at the time of receiving.

<3.3> Dimensional relationship between the diameters of the shear column and the through hole The through hole 22 and the shear column 30 are provided with a diameter difference, and a gap is formed between the peripheral surfaces of the shear column 30 and the through hole 22. ..
This gap functions not only for facilitating the insertion work between the shear column 30 and the through hole 22, but also as a space for allowing a certain range of sliding of the block block wall 20 at the time of receiving.
Since the sliding distance of the block block wall 20 increases in proportion to the gap, this gap is appropriately selected.
When a commercially available steel pipe is used for the shear column 30, this gap may be about 30 to 50 mm.

[Construction method of sabo dam]
Next, the construction method of the sabo dam will be described.

1. 1. Construction of the bottom block block wall <1> Stacking of single blocks As shown in Fig. 4 (A), a plurality of single blocks 21 and 23 are staggered so that the plurality of through holes 22 are aligned on the same vertical line. while placing the piled up at the bottom of the block Katamarikabe 20 _first height.

<2> Connecting work of a single block by a connecting material With reference to FIG. 4B, a connecting work of a single block 21 and 23 groups by a connecting material 25 will be described.
The through holes 22 of the plurality of single blocks 21 and 23 groups stacked in multiple stages are continuous in the vertical direction.
Of the through-holes 22 which multiple exposure, and the like to fill the part consolidating material into the through hole 22 of a plurality of single blocks 21, 23 which multistage manner stacked constituting the block Katamarikabe 20 ₁ of the lowermost The groups are integrally connected by the connecting member 25.
When a solidifying material is used for the connecting material 25, the amount of the solidifying material is small, so that it does not hinder rapid construction.

<3> Insertion work of shear column The insertion work of the shear column 30 will be described with reference to FIG. 4 (B).
The shear column 30 is inserted into another through hole 22 in which the connecting member 25 is not provided.
At this time, previously protruded toward just above the top of the shear column 30 from the bottom of the block Katamarikabe 20 ₁ of the upper surface.

The connecting member 25 and the shear column 30 arranged through the through hole 22 are aligned in a specific direction (parallel or orthogonal to the acting direction of the flowing object load), but may be arranged randomly.
The number of connecting members 25 and shear columns 30 to be installed can be appropriately selected.

2. Referring to construct Figure 2 of the middle block Katamarikabe, the upper surface of the block Katamarikabe 20 ₁ the lowermost, as well as piling Engineering unitary blocks 21, 23, and the connecting Engineering unitary block by connecting members carried The middle block block walls 20 ₂ and 20 ₃ are stacked.
In this case, interposing a shear pillar 30 vertically to the joint portion which is horizontally formed between the bottom of the block Katamarikabe 20 ₁ and the middle of the block Katamarikabe 20 ₂ Noto.

3. 3. Referring to construct Figure 2 of the upper blocks Katamarikabe, the upper surface of the middle block Katamarikabe 20 _3, similarly stacked unitary block 21 and 23 Engineering, connecting Engineering unitary block 21, 23 by the connecting member 25 and building blocks Katamarikabe 20 _4, 20 ₅ of the upper performing insertion Engineering shear pillar 30, and ends the construction of check dams 10 formed water communication portion 11 of the interposition to crest.
Incidentally, the loading number of blocks Katamarikabe 20 ₁ to 20 ₅ which constitute the check dam 10 is not limited to the illustrated number.

In this way, the single blocks 21, 23, the connecting member 25, and the shear column 30 can be carried into the site in the form of being divided into small pieces, and the construction on the site is easy, so that rapid construction is possible.

[Characteristics of Sabo dam]
Next, the characteristics of the sabo dam 10 will be described.

1. 1. From the fact that the plurality of blocks Katamarikabe 20 ₁ to 20 ₅ which constitutes a stable Calculation check dams 10 of check dams are integrally structured with each block unit, gravity each block Katamarikabe 20 were staked in blocks It can be treated as a structure.

<1> stable calculation example check dams 10 as described above while a block prefabricated, because it is out treat each block Katamarikabe 20 ₁ to 20 ₅ as gravity structures, when designing the check dams 10, The stability calculation method for gravity dams can be applied.

When calculating the check dam 10 shown in FIG. 2 as a gravity dam, to Shosa for "slip" and "fall" in each block Katamarikabe 20 ₁ to 20 ₅ which is integrated. That is, the stability calculation of gravity dam blocks Katamarikabe ₂₀ 1 to 20 every _five.
The stable calculation of each block Katamarikabe ₂₀ 1 to 20 every _5, with respect to the vertical load combined with its own weight and overburden load blocks Katamarikabe ₂₀ 1 to 20 _5, the block Katamarikabe ₂₀ 1 to 20 ₅ are borne soil pressure, and discussed horizontal load of the slide force such blocks Katamarikabe loaded on each block Katamarikabe 20 ₁ to 20 ₅ top.

For example shows the stability calculation example of "sliding" and "fall" of the section of the top three blocks Katamarikabe 20 exposed on the ground (20 3 _{to 20 5)} in FIG.
That is, for "falling", consider the vertical force (total own weight) of the three block block walls 20 exposed on the ground, and for "sliding", consider the sliding resistance of the joints of the block block walls 20. Just do it.

<2> Unexpected design In the unexpected case (when an unexpected load acts), each block mass slides (slides) at the horizontal joints of the block blocks 20 _{1 to 25} , but each block block. The frictional resistance of the joints of the walls 20 _{1 to 25} and the shear columns 30 arranged in the vertical direction function as shear keys, so that large deformation of the shear columns 30 can be suppressed, and finally the sabo dam 10 is destroyed. It can be effectively prevented.

Specifically, when unexpected is Shosa slidingly resistance in joint portion of each block Katamarikabe 20 ₁ to 20 _5, the shear resistance of the shear column 30.
The unexpected load, calculates the collapse of friction and shear pillar 30 between joints of each block Katamarikabe 20 ₁ to 20 ₅ as workload and Shosa in comparison with the collision energy of debris.

The design example of unexpected when you top three blocks Katamarikabe 20 exposed on the ground (20 3 _{to 20 5)} the subject shown in FIG.

FIG. 7 shows a model diagram of the collapse of the shear column 30 arranged between the upper block block wall 20u and the lower block block wall 20d, and FIG. 7 (A) of the figure shows a normal flow load is not applied. The time is shown, (B) shows the sliding time when the horizontal force F of the flow-down object load is applied to the upper block block wall 20u, and (C) shows the sliding time of the upper block block wall 20u. It shows the time of failure when the shear column 30 is crushed.

At the time of sliding, the upper block block wall 20u slides by the gap formed between the peripheral surfaces of the shear column 30 and the through hole 22.
When a horizontal force F exceeding the sliding resistance between the block block walls 20u and 20d is applied to the upper block block wall 20u, the shear column 30 is broken (crushed) and slides.
As described above, for an unexpected load, a constant displacement due to sliding between the block block walls 20u and 20d is allowed, and the impact force is relaxed so that the horizontal load F can be received flexibly.

[Other Example 1]
With reference to FIG. 8, another sabo dam 10 opened by laterally penetrating a through hole 12 for water passage through a part of the dam frame will be described.

<1> Through holes for water passage In the sabo dam 10 of this example, one or more through ports 12 having a closed cross-sectional shape are provided in a part of the block block wall 20.
Since the sabo dam 10 is for constructing a plurality of block block walls 20 by stacking a plurality of single blocks 21 and 23 in a staggered manner, some of the single blocks 21 and 23 are pulled out in order to form the through hole 12. Even if assembled, the independence of the block block wall 20 is not impaired.

The cross-sectional shape, opening size, opening height, etc. of the through-hole 12 can be appropriately selected.
The through hole 12 may be formed so as to face the boundary portion of the block block wall 20, or may be formed at a position away from the boundary portion.
Further, it is also possible to form a plurality of through holes 12 in rows or columns at intervals.

<2> Effect of this example When the conventional sabo dam is full of sand, driftwood overflows to the downstream side together with water and earth and stone, and there is a risk of causing serious driftwood damage on the downstream side.
A dredging method for removing accumulated earth and stones is known as a method for recovering the function of a sabo dam, but there are few achievements because it requires a lot of dredging cost and time.

In this example, water, earth and stone, etc. can be discharged through the through hole 12 opened in the middle of the sabo dam 10, so even if the sabo dam 10 is a block assembly type, driftwood can be suppressed while suppressing a rapid rise in water level and accumulation of earth and stone. Damage can be reduced.

Conventionally, a block assembly type sabo dam in which multiple blocks are assembled three-dimensionally is known, but since the joints formed in the vertical and horizontal directions of the blocks are inseparably connected, the independence is ensured. It was not possible to pull out some blocks and assemble them from the viewpoint of.

On the other hand, since the sabo dam 10 of the present invention has a structure in which a plurality of single blocks 21 and 23 are simply stacked in a staggered manner, some of the single blocks 21 and 23 are removed in order to form the through hole 12. Even if they are assembled together, the independence of the block block wall 20 is not impaired.
Therefore, although it is a block-assembled sabo dam 10, it is possible to open a through hole 12 for water passage at an arbitrary position on the dam skeleton.

[Other Example 2]
The upper, lower, left, and right joint surfaces of the single blocks 21 and 23 constituting the block block wall 20 may be formed to be smooth and joined, but unevenness that can be fitted to each other is formed on the joint surface and so-called inlay fitting is performed. May be good.
When the joint surfaces of the adjacent single blocks 21 and 23 are in-row-fitted, the unity of the block block wall 20 is further enhanced, and the connection load due to the connecting member 25 can be reduced.

[Other Example 3]
In the above embodiment, the form in which the upper and lower joint surfaces constituting the joint portion of the block block wall 20 are smoothly formed has been described, but it is also possible to form irregularities that can be fitted to each other on the joint surface of the joint portion and join them. It is possible.
The uneven fitting in this example does not mean a perfect fitting state that completely regulates the water smoothing motion of the block block wall 20, and when an unexpected horizontal force exceeds the fitting force of the unevenness acts on the joint portion. It means an incompletely fitted state that allows the block block wall 20 to slide.
As such incomplete fitting means, for example, the fitting depth of the unevenness is made shallow, the surface of the unevenness is inclined to reduce the fitting resistance, or only the convex portion is fragilely formed and received. A fitting structure such as a configuration in which the convex portion is destroyed at the time of a shot can be applied.

In this example, the joints are easily positioned when the block block walls 20 are stacked up and down, and the workability is improved. Further, when high water stopping property is required for the joints between the block block walls 20, it is possible to deal with it by attaching a sealing material or the like to the joints.

10 ... Sabo dam 11 ... Water passage 12 ... Throughout 20 ... Block block wall 20 _{1 to} 20 ₅ ... Block block wall 21 ... -Single block 22 ... Through hole 23 ... Single block 25 ... Connecting material 30 ... Shear column

Claims (6)

A plurality of blocks Katamarikabe stacked in multiple stages are constructed in situ, gravity comprising a multiple shear pillars positioned through between joint portions of the blocks Katamarikabe which are adjacent in the vertical direction in the vertical Sabo dam,
The block block wall includes a plurality of single blocks having a plurality of through holes penetrating in the vertical direction .
It is an aggregate composed of a connecting material having a total length not exceeding the height of the block block wall and vertically penetrating between a plurality of single blocks to integrate them.
A plurality of single blocks, is formed as a gravity structure integrally connected to block Katamarikabe unit through a connection member which is inserted into the through hole of the part,
The shear column inserted through another through hole through which the connecting material is not inserted does not have a connecting function for integrating a plurality of single blocks.
It is characterized in that the shear column functions as a shear key after allowing the block block wall to slide horizontally at the time of receiving.
Block assembly type sabo dam. A gap is formed between the peripheral surface of another through hole through which the connecting material is not inserted and the shear column located across the joint portion of the plurality of block block walls, and the block block wall slides through the gap. The block-assembled sabo dam according to claim 1, characterized in that it is possible. The block-assembled sabo dam according to claim 1 or 2, wherein the shear column is a steel material capable of shear deformation when received. The block assembly type sabo dam according to any one of claims 1 to 3, wherein the shear columns are arranged along the height direction of the block block wall. A plurality of through holes are formed at equal intervals on the plate surface of the single block so that the through holes are aligned on the same vertical line when a plurality of single blocks constituting the block block wall are stacked in a staggered manner. The block assembly type sabo dam according to any one of claims 1 to 4, wherein the block assembly type sabo dam is characterized. The block-assembled sabo dam according to any one of claims 1 to 5, wherein one or more through holes for water passage are formed laterally through the block block wall.

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