Steel slit dam

Abstract

To provide a steel slit dam excellent in economy, quality, and maintainability by realizing a structure in which, when earth and stone, driftwood, etc., overflow a top of a slit structure, overflowing earth and stone, driftwood, etc., do not collide with a downstream post and a structure in which breakage of some members does not lead to breakage of a slit structure, thereby the whole of non-overflow portions (a dam, an embankment body).SOLUTION: In a steel slit dam, slit structures constructed three-dimensionally by connecting upstream column materials and downstream column materials with connecting materials are installed on a foundation portion between non-overflow portions constructed in a transverse direction of a river. The downstream column materials are provided in a posture rising in a vertical direction from the foundation portion. The slit structure comprises a protruding member that protrudes from an upstream column material and / or a downstream column material located at both ends in the transverse direction of the river to the non-overflow portion. The protruding member is supported by the non-overflow portion so as to be able to transmit stress.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention belongs to the technical field of steel slit dams constructed in valleys, rivers and the like in mountainous areas, which capture boulders, driftwood and the like generated during debris flows and major floods, or attenuate (decelerate) debris flows to prevent disasters in advance.

Background Art

[0002] Regarding steel slit dams, a wide variety of proposals have already been made and there are many practical examples, as exemplified in Patent Documents 1 to 4 below.

[0003] Patent Document 1 discloses a steel slit dam provided with a slit structure having a structure in which the upper end position of a downstream support column of the steel slit dam is lowered to a position low enough that boulders, driftwood and the like in debris flow that vigorously overflow from the vicinity of the upper end position of an upstream support column do not collide therewith, so that the boulders, driftwood and the like jump over the upper end of the inclined downstream support column and fall directly toward the riverbed on the downstream side, thereby physically avoiding collision with the downstream support column.

[0004] Patent Document 2 discloses a steel slit dam provided with a slit structure having a structure that can effectively prevent damage to the inclined downstream support column by providing a crown eave member, one end of which is joined near the upper end of the upstream support column and the other end of which protrudes further downstream than the inclined downstream support column and is received and supported by the downstream support column, thereby realizing a configuration that reduces the possibility that boulders, driftwood and the like flowing down the upper surface of a deposit fall and collide with the downstream support column.

[0005] Patent Document 3 discloses a permeable sabo dam (steel slit dam) provided with a slit structure having a configuration, as a means for preventing damage to the inclined downstream support column, in which an eave extending downstream from the head of the upstream support column is provided to prevent damage to the downstream support column caused by earth and stone falling over the upstream support column as much as possible.

[0006] Patent Document 4 discloses a steel slit dam equipped with a slit structure that exhibits a vertically rising planar structure (flat structure), in which both ends of beam members connected to column members erected with their lower ends embedded in the foundation concrete are inserted into sheath pipes embedded in the dam body and supported between concrete dam bodies (non-overflow sections) formed on both sides in the river width direction of the river. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2017-40081 [Patent Document 2] Japanese Patent Publication No. 2021-143583 [Patent Document 3] Japanese Patent Publication No. 2009-24364 [Patent Document 4] Japanese Patent Publication No. 2009-275434 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] As mentioned above, the steel slit dam described in Patent Document 1 is a useful technology because it can physically avoid collisions with the downstream support pillars with large boulders, driftwood, etc. However, it is implemented with a configuration in which the downstream support pillars are inclined. Therefore, the higher the height of the downstream support pillars (slit structure), the greater the width of the downstream support pillars (the dimension viewed in plan), and the greater the possibility of collision with the downstream support pillars, so there is room for improvement.

[0009] The steel slit dam described in Patent Document 2 has a configuration in which the crest eaves member extends downstream beyond the downstream support column, resulting in a structure in which the protruding crest eaves member is supported in a cantilevered manner. Therefore, if a large piece of soil or rock falls forcefully onto the crest eaves member (especially the protruding portion), the impact of the fall will forcefully act on the crest eaves member, creating a large bending moment that could cause damage to the slit structure, such as bending not only the crest eaves member but also the top of the downstream support column. This concern becomes more pronounced as the height of the downstream support column (slit structure) increases, as the width of the inclined downstream support column increases, and consequently the protruding dimension of the crest eaves member increases. Thus, there is still room for improvement.

[0010] The steel slit dam described in Patent Document 3 has a cantilevered canopy installed near the upper end of the upstream support column. As the height of the downstream support column (slit structure) increases, the width of the inclined downstream support column increases, and consequently the length of the canopy increases. This presents the same problems as described in Patent Document 2, and therefore, there is still room for improvement.

[0011] The steel slit dam described in Patent Document 4 implements the slit structure as a planar structure rising vertically, so there is no need to provide the downstream column members in an inclined position, and in fact, there is no concept of upstream or downstream column members at all. Therefore, the problem of damage to the inclined downstream member, which was a common issue with the steel slit dams described in Patent Documents 1 to 3, is not present. However, the slit structure described in Patent Document 4 is a simple structure in which columns and beams are assembled in a planar manner. As a result, it has fewer components compared to the three-dimensionally constructed slit structures described in Patent Documents 1 to 3, and damage to some components (columns, beams) has a greater impact on the entire slit structure. This can lead to damage to the slit structure, and consequently to damage to the entire dam body (non-overflow section) supporting it, indicating that there is room for improvement.

[0012] Therefore, the present invention was devised in view of the problems of the background technology described above, and its objective is to provide a steel slit dam that is economical, high-quality, and easy to maintain by realizing a structure in which, when soil, rocks, driftwood, etc. overflow the top of the slit structure, the overflowing soil, rocks, driftwood, etc., does not collide with the downstream support column, and a structure in which damage to some members does not lead to damage to the slit structure, and consequently to damage to the entire non-overflow section. Accordingly, the aim is to provide a steel slit dam that allows for a reduction in structural width (installation width) while increasing structural height compared to conventional steel slit dams, making it possible to create dams known as high dams. [Means for solving the problem]

[0013] As a means to solve the above problems, the steel slit dam according to the invention described in claim 1 is a steel slit dam in which a slit structure, which is constructed three-dimensionally by connecting an upstream column member and a downstream column member with a connecting member, is installed in the foundation between non-overflow sections constructed in the transverse direction of the river, The downstream column member is provided in a position that rises vertically from the foundation. The three-dimensionally constructed slit structure includes protruding members that extend from the upstream and / or downstream columns located at both ends in the transverse direction of the river to the non-overflow section, and the protruding members are By being slidably inserted into the sheath tube embedded laterally in the non-overflow section and positioned accordingly, It is characterized by being supported in a way that allows stress to be transmitted to the non-overflow portion.

[0014] request The invention described in claim 2 is, 1 In the steel slit dam described above, the protruding member is provided on the upper half of the upstream column and / or downstream column.

[0015] Claim 3 The invention described in the claims 1 or 2 In the steel slit dam described above, the slit structure is characterized by having a canopy portion that extends downstream from the upper part of the downstream column member. [Effects of the Invention]

[0016] The steel slit dam according to the present invention provides the following effects. (1) The downstream column members that constitute the slit structure are installed in a position that rises vertically from the foundation, so when soil, rocks, driftwood, etc. overflow the top of the slit structure, it is possible to create a structure in which the overflowing soil, rocks, driftwood, etc. do not collide with the downstream support column. Therefore the downstream support column, and by extension teeth By minimizing damage to the slit structure, it is possible to realize a steel slit dam with superior economy, quality, and maintainability. (2) The slit structure can be constructed as a three-dimensional structure with excellent balance performance using upstream column members, downstream column members, and connecting members, etc., so even if some of the constituent members are damaged, it is possible to realize a steel slit dam that can prevent the collapse of the slit structure, and by extension the steel slit dam including the non-overflow section. (3) The lower ends of the upstream and downstream column members that form the legs of the slit structure are embedded in the foundation (concrete foundation, etc.) and erected, and the protruding members provided on the upstream column and / or downstream column members located at both ends of the slit structure are supported so as to be able to transmit stress to the left and right non-overflow sections, thus realizing a rational structure in which the entire steel slit dam, including the slit structure, can resist. Therefore, compared to conventional steel slit dams, it not only contributes to preventing the slit structure from toppling over, but also allows for a reduction in structural width (installation width) while increasing structural height, thus realizing a steel slit dam that can also be constructed as a high dam. (4) By reducing the structural width (installation width) of the slit structure, the amount of overflowing soil, rocks, driftwood, etc. that fall while flowing at the top of the slit structure can be suppressed, thus suppressing damage to connecting members and other components placed inside the slit structure. Furthermore, by reducing the structural width (installation width) of the slit structure, the number of connecting members and other components placed inside the slit structure is also reduced, which inevitably suppresses damage to the aforementioned components. In addition, by reducing the structural width (installation width) of the slit structure, it is possible to make the slit structure slimmer, which increases the design freedom of the non-overflow section (weir, dam body), and by extension, the steel slit dam itself. [BRIEF DESCRIPTION OF THE DRAWINGS]

[0017] [Figure 1] FIG. 1 is a perspective view of the steel slit dam according to the present invention as viewed from the downstream side, with a part shown in perspective view for convenience of illustration. [Figure 2] FIG. 2 is a side view showing a main part of the steel slit dam according to the present invention. [Figure 3] FIG. 3 is a front view of a downstream column member of the steel slit dam according to the present invention as viewed from the downstream side. [Figure 4] FIG. 4 is a front view of an upstream column member of the steel slit dam according to the present invention as viewed from the upstream side. [Figure 5] FIG. 5 is a perspective view showing in detail a connection portion between a slit structure and a non-overflow part of the steel slit dam according to the present invention. [Figure 6] FIG. 6 is a perspective view showing in further detail a connection portion between a slit structure and a non-overflow part of the steel slit dam according to the present invention. [Figure 7] FIG. 7A is a front view showing a sheath pipe used in the present invention, and FIG. 7B is a right side view of the same. [Figure 8] FIG. 8 is a perspective view showing a state where the sheath pipe shown in FIG. 7 is embedded in a non-overflow part. [Figure 9] FIG. 9 is a perspective view of a steel slit dam according to another embodiment, as viewed from the downstream side, with a part shown in perspective view for convenience of illustration. [Figure 10] FIG. 10 is a side view showing a main part of the steel slit dam according to FIG. 9. [Figure 11] FIG. 11 is a front view of a downstream column member of the steel slit dam according to FIG. 9 as viewed from the downstream side. [Figure 12] FIG. 12 is a front view of an upstream column member of the steel slit dam according to FIG. 9 as viewed from the upstream side. [Figure 13] FIG. 13 is a perspective view of a steel slit dam according to another embodiment, as viewed from the downstream side, with a part shown in perspective view for convenience of illustration. [Figure 14] FIG. 14 is a side view showing a main part of the steel slit dam according to FIG. 13. [Figure 15]Figure 13 is a front view of the downstream column of the steel slit dam, as seen from the downstream side. [Figure 16] Figure 13 is a front view of the upstream column of the steel slit dam, as seen from the upstream side. [Figure 17] This is a schematic side view showing variations in the slit structure of the steel slit dam according to the present invention. [Figure 18] This is a schematic side view showing variations in the slit structure of the steel slit dam according to the present invention. [Modes for carrying out the invention]

[0018] Next, an embodiment of the steel slit dam according to the present invention will be described based on the drawings.

[0019] As shown in Figures 1 to 4, the steel slit dam 1 according to the present invention is constructed by installing a slit structure 2, which is constructed three-dimensionally by connecting an upstream column 3 and a downstream column 4 with a connecting member 5, into a foundation 7 between non-overflow sections 6 constructed in the transverse direction (river width direction) of the river. The downstream column member 4 is provided in a position that rises vertically from the foundation 7. The slit structure 2 is provided with protruding members 8 that extend from the upstream column member 3 and / or the downstream column member 4 located at both ends in the transverse direction of the river to the non-overflow section 6, and the protruding members 8 are supported so as to be able to transmit stress to the non-overflow section 6.

[0020] Specifically, the steel slit dam 1 is constructed by installing a slit structure 2 in the direction of the river width on a foundation 7 provided in the opening between non-overflow sections 6 constructed in a river in a mountainous area. In the illustrated example, the slit structure 2 is constructed three-dimensionally by connecting five upstream column members 3 and three downstream column members 4 with multiple connecting members 5. However, the number and size of each column member 3, 4 and connecting member 5 used are not limited to these, and can be appropriately modified according to the structural design. Incidentally, in the figure, reference numeral 11 indicates a support member, and reference numeral 12 indicates a branching steel pipe. The number and size of these can also be appropriately modified according to the structural design. Specifically, the structural design refers to the maximum size of the expected sediment and the maximum length of driftwood, as well as the scale of the non-overflow section 6, the width of the opening (foundation section 7), the characteristics of the river during floods (expected water level, expected flow rate, driftwood flow width), and simulations of capturing sediment and driftwood using image analysis. There are various ways to install the column members 3 and 4 into the foundation 7, but in this embodiment, although detailed drawings are omitted, the lower ends to which the base plates are attached are embedded in the foundation 7. Alternatively, the lower ends can be installed into sheath pipes that have been pre-embedded in the foundation 7. Furthermore, although the upper surface of the foundation 7 is shown as a horizontal surface in the illustrated example, it is not limited to this and may be constructed with a slope that follows the gradient of the riverbed. Note that the upstream column member 3, downstream column member 4, connecting member 5, and support member 11 in the illustrated example appear to be made from a single steel pipe for illustrative purposes. While it is certainly possible to use a single steel pipe, in practice, it is more common to use a divisible (or more divisible) segmented structure in which a pair of flanges provided on the end faces of opposing steel pipes are bolted together (flange joint) to connect them (see, for example, Patent Document 3 filed by the present applicant).

[0021] All of the downstream column members 4 (three in the illustrated example) are erected with their lower ends embedded in the foundation 7, and are positioned to rise vertically from the foundation 7. The two downstream column members 4 located at the left and right ends are each equipped with protruding members 8 that extend outwards to the left and right non-overflow sections 6. As can be clearly seen in Figure 3, the protruding members 8 are provided on the left and right extensions of the upper three sections of the five-tiered connecting member 5 that connects adjacent downstream column members 4, corresponding to the upper half of the first half, and are supported so as to be able to transmit stress to the left and right non-overflow sections 6.

[0022] As a means of supporting the protruding member 8 so as to be able to transmit stress to the non-overflow section 6, the protruding member 8 in this embodiment is, for example, implemented as a segmented structure joined by a flange 10, as can be clearly seen in Figures 5 and 6. The protruding member 8 at the end is inserted into a sheath pipe 9 embedded laterally in the non-overflow section 6, and the joined protruding member 8 is flange-joined with the protruding member 8 on the main body side of the slit structure 2, thereby supporting the left and right non-overflow sections 6 so as to be able to transmit stress.

[0023] Specifically, the protruding member 8 on the end side is made of a metal pipe (steel pipe) with a flange 10 attached to one end, and is joined to the flange 10 provided on the protruding member 8 on the main body side by a means of flange joining, but it can also be done by welding. In short, as long as the protruding member 8 implemented in the divided structure can be added to have the required strength and rigidity, and can be supported in a way that stress can be transmitted to the left and right non-overflow sections 6, any conventional joining means can be applied.

[0024] As shown in Figures 7 and 8, the sheath pipe 9 consists of a pipe body 9a and a positioning portion (overlap portion on the surface of the non-overflow portion 6) 9b provided at its end. The inner diameter of the pipe body 9a is slightly larger than the outer diameter of the protruding member (steel pipe) 8 at the end, and smaller than the outer diameter of the flange 10. The length of the pipe body 9a is also such that it can adequately accommodate (slide on) the extended protruding member 8. Incidentally, the reference numeral 9c in the figures indicates a guide material (spacer).

[0025] The significance of adopting the method of inserting the protruding member 8 through the sheath pipe 9, rather than simply embedding it in the non-overflow section 6, is that by creating a slidable structure between the sheath pipe 9 and the protruding member 8 that can absorb the expansion and contraction strain of each column member 3, 4, or connecting member 5 constituting the slit structure 2, thermal stress is relieved, and cracking of concrete and the like is suppressed. Furthermore, the stress (especially shear stress) transmitted to the sheath pipe 9 via the protruding member 8 of the slit structure 2 can be transmitted to the non-overflow section 6, preventing cracking around the sheath pipe 9 without stress concentration.

[0026] For reference, the components constituting the slit structure 2, such as the upstream column member 3, the downstream column member 4, the connecting member 5, and the protruding member 8, are mainly made of steel pipes (metal pipes), with sizes of approximately 400-600 mm in outer diameter and 9-22 mm in wall thickness being preferred. The spacing (installation width) between the upstream column member 3 and the downstream column member 4 can be as small as 2-3 m. Furthermore, the overall size of the slit structure 2 can be as large as 10-12 m in height, and due to the unique configuration of this invention, it can also be 15 m or more, which is referred to as a high dam.

[0027] The steel slit dam with the above configuration provides the following effects. (1) Since the downstream column member 4 is installed in a position that rises vertically from the foundation 7, when soil, rocks, driftwood, etc. overflow the top of the slit structure 2, a structure can be realized in which the overflowing soil, rocks, driftwood, etc. do not collide with the downstream support column 4. Therefore, damage to the downstream support column 4 and, consequently, the slit structure 2 can be prevented as much as possible, making it possible to realize a steel slit dam with excellent economy, quality, and maintainability. (2) The slit structure 2 can be constructed as a three-dimensional structure with excellent balance performance using the upstream column 3, the downstream column 4, and the connecting members 5, etc., so even if some of the constituent members are damaged, a steel slit dam can be realized that can prevent the collapse of the slit structure 2, and by extension the steel slit dam 1 including the non-overflow section 6. (3) The lower ends of the upstream column members 3 and downstream column members 4 that form the legs of the slit structure 2 are embedded in the foundation (concrete foundation, etc.) 7 and erected, and the protruding members 8 provided on the downstream column members 4 located at both ends of the slit structure 2 are supported so as to be able to transmit stress to the left and right non-overflow sections 6, thus enabling a rational structure in which the entire steel slit dam, including the slit structure 2, can resist. Therefore, compared to conventional steel slit dams, it not only contributes to preventing the slit structure 2 from toppling over, but also allows for an increase in structural height while reducing the structural width (installation width), thus enabling the construction of a steel slit dam that can also be called a high dam. (4) By reducing the structural width (installation width) of the slit structure 2, the amount of overflowing soil, rocks, driftwood, etc. that fall while flowing at the top of the slit structure 2 can be suppressed, thus suppressing damage to components such as connecting members 5 arranged inside the slit structure 2. Also, by reducing the structural width (installation width) of the slit structure 2, the number of components such as connecting members 5 arranged inside the slit structure 2 is also reduced, so damage to the said components is inevitably suppressed. Furthermore, by reducing the structural width (installation width) of the slit structure 2, it is possible to make the slit structure 2 slimmer, which increases the design freedom of the non-overflow section (weir, dam body) 6 and, by extension, the steel slit dam 1 itself.

[0028] Furthermore, the slit structure 2 of the steel slit dam 1 shown in Figures 1 to 4 above is implemented with protruding members 8 provided on the downstream column members 4 located at both ends, but is not limited to this structure. For example, as shown in Figures 9 to 12, the protruding member 8 can also be provided in a five-tiered configuration on the left and right extensions at the same level as all of the five-tiered connecting members 5 that connect adjacent downstream column members 4. Alternatively, as shown in Figures 13 to 16, the protruding member 8 can also be provided in a five-tiered configuration on the left and right extensions at the same level as all of the five-tiered connecting members 5 that connect adjacent upstream column members 3. Furthermore, although not shown in the figures, a mixed structure of these can also be implemented, namely, a structure in which protruding members 8 (one or more tiers) are provided on the upstream column member 3 and the downstream column member 4, and these protruding members 8 are supported on the left and right non-overflow sections 6 in a manner that allows stress to be transmitted. These variations, like the embodiments described with reference to Figures 1 to 4, also possess the same characteristics of the slit structure 2 according to the present invention, namely the configuration in which the downstream column member 4 is provided in a position rising vertically from the foundation 7, and the configuration in which the slit structure 2 is provided with protruding members 8 that extend from the upstream column member 3 and / or downstream column member 4 located at both ends in the transverse direction of the river to the left and right non-overflow sections 6, and the protruding members 8 are supported so as to be able to transmit stress to the left and right non-overflow sections 6.

[0029] While embodiments of the present invention have been described above with reference to the drawings, it should be noted that the present invention is not limited to the illustrated examples and includes design modifications and variations in application that are commonly practiced by those skilled in the art, without departing from the technical spirit thereof.

[0030] For example, the number of stages of the protruding member 8 can be as few as one, or as two or more, as shown in the illustrated example, depending on the structural design. Furthermore, the installation location of the protruding member 8 is not limited to the same level as the connecting member 5, but can be installed at any part of the upstream column member 3 and / or the downstream column member 4. However, from the viewpoint of preventing the slit structure 2 from toppling over, it is effective to install it in the upper half (upper part) of the upstream column member 3 and / or the downstream column member 4, but even if it is installed only in the lower part, it will still have the effect of transmitting stress to the non-overflow section 6. In short, the design can be appropriately modified according to the structural design that takes into account the maximum size of the expected soil and rocks, the maximum length of driftwood, etc., as described above. Furthermore, although the illustrated example shows the upstream column member 3 inclined, it is not limited to this configuration. As illustrated in Figure 17, it can also be implemented in a vertical position, similar to the downstream column member 4. The design can be appropriately modified according to the structural design, including the form of the upstream side of the non-overflow section 6. Furthermore, in the illustrated example, the slit structure 2 is implemented with a canopy portion extending downstream from the upper part of the downstream column member 4. Specifically, the slit structure 2 is implemented in which one end of the connecting member 5 at the top of the top of the upstream column member 3 and the top of the downstream column member 4 extends slightly downstream from the downstream column member 4 to form a canopy portion (eaves portion). Such a structure further improves the effect of preventing collisions with the downstream support column 4 by guiding overflowing soil, rocks, driftwood, etc. further downstream, and can be implemented as appropriate without departing from the technical concept of the present invention. Furthermore, in the illustrated example, the tops (heights) of the upstream column 3 and the downstream column 4 are aligned. However, by setting the height of the downstream column 4 lower than that of the upstream column 3, the effect of preventing overflowing soil, rocks, driftwood, etc. from colliding with the downstream support can be further improved. This can be done as appropriate without departing from the technical concept of the present invention. Furthermore, the slit structure 2 used in the steel slit dam 1 according to the present invention only needs to be constructed three-dimensionally by connecting the upstream column member 3 and the downstream column member 4 with a connecting member 5. Therefore, as illustrated in Figure 18, it is of course possible to implement a structure without a connecting member 5 at the top of the top of the upstream column member 3 and the top of the downstream column member 4. Incidentally, the slit structure 2 shown in Figure 18 is also implemented with the aforementioned canopy section. [Explanation of Symbols]

[0031] 1. Steel slit dam 2 Slit structure 3 Upstream column member 4 Downstream column member 5. Connecting material 6 Non-overflow area (dam, embankment body) 7 Foundation 8. Protruding member 9 Sheath tube 9a Tube body 9b Positioning section (overlap) 9c guide material 10 flanges 11 Support material 12 branch steel pipe

Claims

1. In a steel slit dam, a slit structure is constructed three-dimensionally by connecting upstream and downstream column members with connecting members, and this slit structure is installed in the foundation between non-overflow sections constructed in the transverse direction of the river. The downstream column member is provided in a position that rises vertically from the foundation. The steel slit dam is characterized in that the three-dimensionally constructed slit structure includes protruding members that extend from upstream and / or downstream column members located at both ends in the transverse direction of the river to the non-overflow section, and the protruding members are supported in such a way that stress can be transmitted to the non-overflow section by being slidably inserted and positioned within a sheath pipe embedded laterally in the non-overflow section.

2. The steel slit dam according to claim 1, characterized in that the protruding member is provided on the upper half of the upstream column member and / or the downstream column member.

3. The steel slit dam according to claim 1 or 2, characterized in that the slit structure is provided with an overhang portion extending downstream from the upper part of the downstream column member.

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