JPH1025730A - Bridge type fish ladder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fish ladder, in which the long-sized fish ladder can be constructed easily by executing the minimum construction of works to the bedrock of a river bank or a river-bed. SOLUTION: Two or more of piers 3 are disposed in upright on a bedrock 2 at intervals, and bridge girder blocks 10 precast-molded of concrete are placed on the top faces 4, 5 of the piers 3 in a two row shape through adjusted mortar 7 and simple rubber bearing bodies 8. Sections among the piers 3 and the bridge girder blocks 10 and sections among the bridge girder blocks 10 in two rows are fixed surely, and a bridge girder 15 in a specified grade is formed. Fish ladder blocks 20 precast-molded of concrete are installed and joined on the top faces of bridge girder blocks 10 through adjusted mortar 17. Sections among the bridge girder blocks 10 and the fish ladder blocks 20 are also fastened surely, and a fish-ladder water channel 23 in a specified grade is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a river dam, weir,
The present invention relates to a fishway which is attached to a headwork or the like to enable aquatic organisms such as fish to go upstream.

[0002]

2. Description of the Related Art A conventional fishway is constructed by excavating bedrock on a riverbank or a riverbed, laying a foundation on the bedrock with concrete, and then constructing the foundation with cast-in-place concrete. A large number of fishway blocks precast with concrete were installed and connected.

[0003]

However, when the height difference between the weirs is large, it is necessary to construct a fishway to a certain length in order to secure a gradient from which fish can run up. The bedrock of the riverbed had to be excavated over a long distance, and foundation work had to be performed on the bedrock for a long time, which made the work extremely difficult.

[0004] In the case of a stair-type system, a fishway constructed on a relatively high sabo dam requires several turns to complicate the structure itself.

[0005] Therefore, an object of the present invention is to perform a minimum amount of work on a riverbank or a bed without excavating the bedrock over a long distance or performing a long foundation work with concrete on the bedrock. Accordingly, it is an object of the present invention to provide a bridge-type fishway in which a long fishway can be easily constructed.

[0006]

In order to solve the above-mentioned problems, a bridge-type fishway according to the present invention has at least two piers erected on a bedrock at an interval, and is precast by concrete between the piers. The bridge girder block is bridged to form a bridge girder having a predetermined gradient, and a fishway block precast by concrete is installed on the bridge girder block.

[0007] The bridge girder blocks may be bridged in a row, but it is preferable to bridge the bridge girder blocks in a plurality of rows in order to reduce the size and weight of the bridge girder block alone.

The following can be exemplified as the fishway block. A bottom wall, a pair of side walls erected on both side edges of the bottom wall, and a partition wall provided in a fishway waterway constituted by the bottom wall and the pair of side walls. A bottom wall, a pair of side walls erected on both side edges of the bottom wall, and a partition wall erected at an intermediate portion in the width direction of the bottom wall to partition the inside of the fishway block into a fishway channel and a priming channel; With a partition provided in the fishway waterway.

[0009] The partition walls are used to create a rest area for fish by relaxing the water flow, and to ensure an appropriate overflow depth and shape for the fish. The bulkheads can be provided in the middle or at the ends of the individual fishway blocks.

It is preferable that a notch is formed in a part of the upper edge of the partition wall so that the fish can select the level and can get over it. In particular, the cutouts make it easier for large fish to get over.

When the partition is provided, a convex wall portion which is slightly higher than the upper edge of the partition wall is provided at the upper edge of the side wall, and excess water in the fishway channel is discharged from the upper edge of the side wall other than the convex wall portion to the outside of the fishway block. It is preferable to configure so as to overflow.

[0012] Between the pier and the bridge girder block, and between the bridge girder block and the fishway block, for example, anchor reinforcing steel,
It can be fixed by various fixing means such as mortar, fixing metal fittings, concave and convex fitting. Further, two or more fishway blocks can be connected to each other, and the connecting means is not particularly limited.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1, 6, etc., the bridge-type fishway 1 of the present embodiment is constructed with a pier 3, a bridge girder block 10, and a fishway block 20 as main components.

Two or more concrete piers 3 are erected at intervals on a bed 2 of a riverbank or riverbed along the mountain surface, and the adjacent downstream piers 3 and upstream piers 3 Are arranged so as to have a predetermined pitch (center-to-center distance) and a predetermined height difference so as to have a predetermined gradient. Pier 3
Has a two-stage structure of a lower upper surface 4 on the downstream side and a higher upper surface 5 on the upstream side, and two anchor reinforcing bars 6 planted on the pier 3 project from the upper surfaces 4, 5.

As shown in FIG. 2, FIG. 3, FIG.
Adjustment mortar 7 on the upper surface 4 and 5
A simple rubber bearing 8 having a thickness of about 10 to 30 mm is provided on the adjusting mortar 7. A bridge girder block 10 made of prestressed concrete or reinforced concrete precast by concrete is bridged between the piers 3 in two rows. The reason why the bridge girder is formed in two rows is to reduce the size and weight of the single bridge girder block 10 which tends to be heavy because it is long. Therefore, the width of the bridge girder block 10 is less than half the width of the pier 3. The length of the bridge girder block 10 is substantially equal to a predetermined pitch between the piers 3, and the downstream end of the bridge girder block 10 is mounted on the simple rubber bearing 8 on the high upper surface 5 of the downstream pier 3, The upstream end is the pier 3 on the upstream side.
Is mounted on a simple rubber bearing 8 on the upper surface 4 having a low height.

As shown in FIG. 2, two rows of bridge girder blocks 1
Between 0 and 40-80 mm the anchor rebar 6 enters
A small gap is opened, and the gap is filled with a non-shrink mortar 11 so as to embed and fix the protrusion of the anchor reinforcing bar 6. As shown in FIG. 3 and FIG. 5, a plurality of horizontal braided reinforcing bars 12 penetrating the two bridge girder blocks 10, 10 in the width direction are spaced through two bridge girder blocks 10 at intervals.
A central portion of the horizontal reinforcing bar 12 is embedded and fixed in the non-shrink mortar 11. In addition, a plurality of notches 13 at both ends of the horizontal reinforcing bar 12 appearing at the outer edges of the two rows of bridge girder blocks 10.
The notch 13 is filled with a non-shrink mortar 14 so as to embed and fix both ends of the horizontal reinforcing bar 12.

Thus, the pier 3 and the bridge girder block 1
0, and between the two rows of bridge girder blocks 10 are securely fixed, and a bridge girder 15 having a predetermined gradient is formed. In addition,
The bridge girder blocks 10 arranged in the length direction may or may not be joined with mortar or the like. Two anchor reinforcing bars 16 implanted in the bridge girder block 10 protrude from the upper surface of the bridge girder block 10.

On the upper surface of the bridge girder block 10, an adjusting mortar 17 is laid and joined to a thickness of about 20 to 40 mm. On the adjustment mortar 17, a fishway block 20 precast and formed of concrete so as to embed a reinforcing steel bar is installed and joined. In this embodiment,
Three fishway blocks 20 are arranged on the bridge girder block 10 in two rows and one unit in the length direction.

The fishway block 20 includes a bottom wall 21 and the bottom wall 2.
A fishway channel 23 is formed by a pair of side walls 22 erected on both side edges of the first side, and the upper end is open. At the center in the longitudinal direction of the bottom wall 21, a partition wall 24 is provided to alleviate the water flow to create a resting place for fish and to secure an appropriate overflow depth and shape for the fish. Are joined to both side walls 22 to reinforce the fishway block 20. A notch 25 is formed at one end of the upper edge of the partition 24. At the center of the upper edge of the side wall 22, an arc-shaped convex wall 26 which is one level higher than the upper edge of the partition 24 is provided.

As shown in FIGS. 4 and 5, the bottom wall 21 of the fishway block 20 is formed with a through hole 27 into which the anchor reinforcing bar 16 enters. Is filled with a non-shrink mortar 28 so that the mortar 28 is embedded and fixed. In this way, the space between the bridge girder block 10 and the fishway block 20 is securely fixed, and the fishway waterway 23 having a predetermined gradient is formed. The fishway blocks 20 arranged in the longitudinal direction are connected by fitting the convex portion 29 and the concave portion 30 on the end faces, and the end faces are sealed with non-shrink mortar (not shown).

According to the bridge-type fishway 1 of the present embodiment, the following effects can be obtained. The bedrock 2 on the riverbank or riverbed needs to be subjected to a minimum amount of construction work for erecting the pier 3 and does not require excavation or foundation work over a long distance as in the past. Even one can be easily constructed.

When a fishway is constructed on a relatively high sabo dam, a particularly long fishway is required.
Can be easily constructed for the above-described reason, so that there is no need to fold it as in the conventional staircase type, and the structure can be simplified.

Since the bridge girder block 10 and the fishway block 20 are formed by precasting, it is possible to omit a reinforcing step, a formwork step, a concrete placing step, and the like at the site, and to reduce the number of steps in the bridge-type fishway 1. Can be constructed in a short time.

Since the bridge girder blocks 10 are bridged in two rows, the size of the bridge girder blocks 10 can be reduced in size and weight, and the transportation and handling thereof can be facilitated.

The upper edge of the partition wall 24 has two types of levels due to the cutouts 25, so that fish can select the level and get over it. In particular, the notch 25 makes it easy for a large fish to get over.

The arc-shaped convex wall portion 26 of the side wall 22 can prevent fishes passing over the partition wall 24 from jumping out of the fishway block 20 and can give the viewer a sense of beauty. In addition, when the water W in the fishway channel 23 increases from the upper edge of the side wall 22 other than the arc-shaped convex wall portion 26, extra water overflows out of the fishway block 20, so that the water depth of the fishway channel 23 is kept constant. (See FIG. 1).

The present invention is not limited to the above embodiments, and may be embodied by appropriately changing the shape and configuration of each part without departing from the spirit of the present invention. (1) The bridge girder blocks 10 are arranged in one row or three rows or more. (2) Depending on the design strength of the pier 3 and the bridge girder block 10, one pass, that is, only two piers 3 having a large pitch can be used. (3) The fixing means between the pier 3 and the bridge girder block 10 and the fixing means between the bridge girder block 10 and the fishway block 20 are changed.

(4) As shown in FIG. 7, the fishway block 2
0, a partition wall 31 is erected in the middle of the width direction.
Partitioning the inside of the fishway block 20 into a fishway waterway 23 and a waterway 32. (5) To provide a pattern (for example, a concavo-convex pattern imitating natural stone) on the inner surface or outer surface of the fishway block 20 to reduce the artificial feeling and harmonize with the surrounding landscape. In particular, in the case where an uneven pattern is provided on the inner surface, algae and the like are easily attached, and the habitat environment is improved.

[0029]

As described above in detail, according to the bridge type fishway according to the first aspect of the present invention, rocks on the riverbank or riverbed are excavated over a long distance, or a long foundation is constructed on the rocks with concrete. Even without doing so, a long fishway can be easily constructed by performing a minimum amount of construction on the bedrock.

In addition to the above effects, the bridge type fishway according to the second aspect of the present invention reduces the size and weight of the bridge girder block itself,
Its transportation and handling become easier.

Further, according to the bridge-type fishway according to the third aspect of the present invention, the partition walls alleviate the water flow in the fishway channel and create a resting place for the fish, so that the fish can easily go up.

Further, according to the bridge type fishway according to the invention of claim 4, it is not necessary to separately construct a priming waterway.

Further, according to the bridge-type fishway according to the fifth aspect of the present invention, fish can get over by selecting the level of the bulkhead, and particularly, the cutout portion makes it easy for large fish to get over.

According to the bridge type fishway according to the sixth aspect of the present invention, it is possible to prevent fishes going over the partition from jumping out of the fishway block and to keep the water depth of the fishway channel constant.

[Brief description of the drawings]

FIG. 1 is a front view showing a bridge type fishway according to an embodiment of the present invention.

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

FIG. 3 is a sectional view taken along line III-III of FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 1;

FIG. 5 is a partially exploded perspective view of the bridge-type fishway.

FIG. 6 is a partial perspective view of the bridge-type fishway.

FIG. 7 is a sectional view showing a modified example of the fishway block.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bridge-type fishway 2 Bedrock 3 Bridge pier 10 Bridge girder block 15 Bridge girder 20 Fishway block 21 Bottom wall 22 Side wall 23 Fishway waterway 24 Partition wall 25 Notch 26 Arc-shaped convex wall part 31 Partition wall 32 Priming waterway W Water

Claims (6)

[Claims] At least two bridge piers are erected on a bedrock at intervals, and a bridge girder block precast by concrete is bridged between the piers to form a bridge girder having a predetermined slope, and the bridge girder is placed on the bridge girder block. A bridge-type fishway constructed by installing fishway blocks precast by concrete. 2. The bridge type fishway according to claim 1, wherein the bridge girder blocks are bridged in a plurality of rows. 3. The fishway block includes a bottom wall, a pair of side walls erected on both side edges of the bottom wall, and a partition wall provided in a fishway waterway constituted by the bottom wall and the pair of side walls. The bridge type fishway according to claim 1 or 2, further comprising: 4. The fishway block includes a bottom wall, a pair of side walls erected on both side edges of the bottom wall, and an erected midway in the width direction of the bottom wall. 3. The bridge type fishway according to claim 1, further comprising a partition wall for partitioning into a priming waterway and a partition wall provided in the fishway waterway. 5. The bridge-type fishway according to claim 3, wherein a notch is formed in a part of an upper edge of the partition wall. 6. An upper edge of the side wall is provided with a convex wall portion which is slightly higher than an upper edge of the partition wall, and excess water of the fishway channel overflows from the upper edge of the side wall other than the convex wall portion to the outside of the fishway block. The bridge-type fishway according to claim 3, 4 or 5, wherein: