JPS5820347B2 - Flexible joints for irrigation structures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION 1. The present invention relates to a flexible joint for water conservancy structures, such as open conduits such as square ditches, or culverts used for water and sewerage systems, public ditches, underground passages, and the like.

In general, water conservancy structures placed on soft reclaimed land or ground with changing strata are subject to relative displacement such as uneven subsidence of the ground, resulting in cracks in the frame and water leakage, or damage to the frame itself. To prevent this, measures are taken to connect irrigation structures by arranging flexible joints at important points.

Taking the example of a culvert, a conventional flexible joint simply connects both ends of a flexible member made of an elastic material such as rubber or synthetic resin or a variable shape material such as a thin steel plate to the concrete of the opposing culvert opening. It is either embedded and fixed in the frame, or a cylindrical flexible member is installed across both culverts along the inner circumferential surface of the culvert opening, and both ends are anchored to the concrete frame.

However, the former type of flexible joint has the problem of not being able to follow large relative displacements that occur between the opposing spaces, and the latter type of flexible joint has the problem that it cannot be flexed due to external pressure such as groundwater or earth and sand. There have been problems such as the parts bulging out inside the culvert, reducing durability, being damaged by stones and the like in the flowing water, and increasing the resistance to flowing water inside the culvert.

Also, open-drain flexible joints suffer from the same problems as those described above for under-drain flexible joints.

An object of the present invention is to provide a new flexible joint for irrigation structures that can not only solve all of these problems but also improve pressure resistance.

Embodiments of the flexible joint for irrigation structures of the present invention will be described below with reference to the drawings.

Fig. 1 shows a case where the flexible joint of the present invention is applied to an open conduit, and Fig. 2 shows a case where the flexible joint of the present invention is applied to an underdrain.

In the figure, 1 and 1' indicate an example of a pair of irrigation structures to be connected, and a flexible member 2 made of an elastic material such as rubber or synthetic resin is straddled between the irrigation structures 1 and 1'. It is set up.

Note that the shape of the irrigation structures 1, 1' is not limited to the square-shaped groove shown in FIG. 1 or the rectangular cross-section culvert shown in FIG. 2, but may take any desired cross-sectional shape.

In addition, in the illustrated example, the water conservancy structures 1 and 1' are made of concrete, but they may also be made of steel.
Further, the structure may be either an integral type or a segment type.

In this case, a flexible joint may be provided between the irrigation structures 1 and 1' via a means such as an auxiliary segment (not shown) to facilitate attachment of the flexible joint to the irrigation structures 1 and 1', as necessary. A flexible joint may be inserted.

Figures 3 and 4 are water conservancy structures 1.1' in Figures 1 and 2.
This figure shows the cross-sectional structure of the connecting part, but as it is clear from the figure, it has a symmetrical structure, so in the following explanation, only one will be mainly explained, and the other will be referred to the reference numeral of the one member. Duplicate explanations will be omitted as necessary by adding dashes and numerals.

In FIGS. 3 and 4, a step 3 is formed on the inner periphery of the end of the irrigation structure 1, and a flexible member 2 is provided straddling the step 3, 3' of each irrigation structure 1, 1'. is straddled.

The flexible member 2 has a flexible portion 2a having a cross-sectional shape including a waveform, and attachment portions 2b extending horizontally from both ends of the flexible portion 2a.

In the embodiment shown in FIG. 3, the flexible portion 2a consists of only a waveform, and in the embodiment shown in FIG. Although it is a combination type with the part 2a-2, both cases are the same in that they include waveforms.

Although the waveform has two peaks in the illustrated example, it is not limited to this, and may have one or three or more peaks.

The shape of the wave is a trapezoid with the waveform apex 2a-1 as the short side in order to reduce the width l of the apex 2a-1 in the sense that it is difficult to deform when the waveform apex 2a-1 receives pressure load. .

It is desirable that the shape be formed into a similar shape.

In addition, in the embodiment shown in FIG.
It is formed to have a relatively thin thickness so that it can be divided before a-3 and follow this relative displacement.

It is desirable to be able to do so.

The flexible portion 2a of the flexible member 2 has its top portion flush with the inner circumferential surface of the irrigation structure 1, and the side portion 2a.
-3 and the troughs of the waves existing on the side portions 2a-3' are aligned with the inner circumferential surface 3a of the stepped portion 3, and are installed across both water conservancy structures 1 and 1'.

The flexible member 2 is attached to the inner circumferential surfaces 3a, 3 of the stepped portions 3, 3' of both irrigation structures 1, 1' at the mounting portions 2b, 2b' at both ends thereof.
It is anchored at a'.

This anchoring is done by applying the attachment part 2b to the anchoring plate 4 which is fixed in advance to the irrigation structure 1 via the anchor 4a, and sandwiching the attachment part 2b between the anchoring plate 4 and the plate 5, This is done by tightening using bolts 6 and nuts 7, or by other means that can achieve the same function.

Irrigation structure frame material 8 is loaded onto the inner peripheral side of attachment portion 2b anchored to step portion 3.

That is, if the irrigation structure 1 is made of concrete, it may be filled with concrete, mortar, etc., and if the irrigation structure 1 is made of steel, a backing plate made of steel, synthetic resin, etc. may be attached.

The loaded irrigation structure frame material 8 is filled up to the outer surface of the side part 2a-3 of the flexible part 2a, and covers as much of the flexible member 2a as possible, and buckles on the side part 2a-3 as the load increases. Prevent this from occurring.

Further, the troughs of the waves, which are opened inside the irrigation structure 1 of the flexible portion 2a including the corrugations, are filled with a joint material 9 made of sponge or the like.

With this joint material 9 and the water conservancy structure frame material 8,
The flexible member 2 is connected to the water conservancy structure 1 except for the inner circumference side top portion 2a-1.
Exposure to the inside is prevented.

Furthermore, although a joint material 10 is interposed in the gap between the end faces of the water conservancy structure 1.1, it is not necessarily necessary to do so.

The operation of the flexible joint having the above configuration will be explained.

3 and 4 show the state before relative displacement occurs between the irrigation structures 1 and 1'.

When internal pressure is applied to the flexible joint in this state, this load is supported by the stepped inner circumferential surface 3a located along the valley of the flexible member 2 via the flexible member 2.

In this case, if the flexible part 2a is formed into a waveform close to a trapezoid, the deformation of the top part 2a-1 is small, and the side part 2a-3 is supported by the irrigation structure frame material 8, joint material 9, etc. Therefore, buckling does not occur.

A large load can be supported by these combined effects.

In addition, external pressure loads such as earth and sand and external water pressure applied to the flexible joint are essentially supported by the irrigation structure frame material 8 on the back side of the stepped section 3, so pressure resistance is increased and the flexible joint is attached to the irrigation structure 1.
There is no risk of bulging inward and increasing resistance to running water, or of being damaged by boulders, etc. in running water.

Furthermore, since the flexible joint is covered except for the inner circumferential top portion 2a-1, there is no risk of damage from boulders or the like in flowing water.

When a displacement occurs in the axial direction or perpendicular direction to the axis between the irrigation structures 1 and 1', this flexible joint has a flexible part 2a including a corrugated shape, and is loaded on the inner peripheral side of the mounting part 2b. Since the water conservancy structure frame material is in a state where the top part 2a-1 of the flexible part 2a is exposed on the inner surface of the water conservancy structure, the deformation of the flexible part 2a is not inhibited, and the inner periphery of the attachment part 2b is It can smoothly follow the displacement and deform while maintaining the water stop function without destroying the water conservancy structure frame material loaded on the side.

In this case, in the embodiment shown in Fig. 4, the straight portion 2a-2 may be separated, but even if it is separated, the corrugated portion remains in a healthy state, so the water stop function is completely maintained. .

Therefore, since it includes a waveform, it is possible to follow a large relative displacement.

When using the flexible joint of the irrigation structure of the present invention, the following various effects can be obtained.

First, since the flexible member is made of an elastic material having a flexible section having a cross-sectional shape including a waveform and attachment sections provided at both ends of the flexible section, it is possible to follow the relative displacement between the irrigation structures. You can greatly improve your sexuality.

This followability is achieved because the irrigation structure frame material loaded on the inner circumferential side of the attachment part of the flexible member exposes the top of the flexible part of the flexible member to the inner surface of the irrigation structure. The deformation of the flexible portion of the flexible member is not inhibited by the irrigation structure, and the relative displacement between the irrigation structures is smoothly performed.

In addition, at this time, since the irrigation structure frame materials loaded in the mounting parts provided on both sides of the flexible member are separated by the tops of the flexible parts of the flexible member, It will not be peeled off or damaged due to the relative displacement of the water storage structure, and the water-tightness of the mounting portion can be maintained due to the presence of the loaded irrigation structure frame material.

Next, a step was formed in a pair of irrigation structures, a flexible member was placed across the step, and the irrigation structure frame material was loaded on the inner circumferential side of the flexible member. It is possible to prevent bulging toward the inner surface of the structure, and to avoid an increase in water flow resistance due to the bulge.

Moreover, since this structure prevents most of the flexible member from being exposed, it is possible to prevent the flexible member from being damaged by dirt, stones, etc. in flowing water.

Since the inner periphery of the flexible part of the flexible member is aligned with the inner surface of the irrigation structure and the top of the flexible part is aligned with the inner periphery of the stepped part, it is possible to minimize the flow resistance of water flowing counterflow through the irrigation structure. Moreover, the pressure resistance against loads applied from inside and outside of the irrigation structure can be greatly improved.

In this case, if the shape of the corrugated cross section is made into a shape close to a trapezoid, the pressure resistance performance can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view when the flexible joint of the irrigation structure of the present invention is applied to a ■-shaped groove, FIG. 2 is a perspective view when the flexible joint of the irrigation structure of the present invention is applied to a culvert, FIG. 3 is a cross-sectional view of one embodiment of the present invention taken along line A-A in FIGS. 1 and 2, and FIG. FIG. 4 is a cross-sectional view of another embodiment different from FIG. 3; 1.1'... Water conservancy structure, 2... Flexible member, 2a. 2a'... Flexible part, 2a L2a-1'... Top part, 2a-2, 2a-2'... Straight part, 2a-3, 2
a-3'...Side part, 2b, 2b'...Mounting part, 3,
3'...Step part, 3a, 3a'...Step part inner peripheral surface, 4,
4'... Anchor board, 4a. 4a'... Anchor, 5, 5'... Back plate, 6, 6'
...Bolt, 7.7'...Nut, 8,8'...
Irrigation structure frame material, 9゜10...Mountain material.

Claims (1)

[Scope of Claims] 1. Steps are formed on the inner peripheries of opposing ends of a pair of irrigation structures to be connected, respectively, and the steps are straddled over both steps. A flexible member made of an elastic material having a flexible section having a cross-sectional shape including a waveform and mounting sections provided at both ends of the flexible section can be fitted with the top of the flexible section attached to the inner surface of the irrigation structure. The valley part of the flexible part is placed astride the inner circumferential surface of the stepped part, and the top of the flexible part is placed on the inner circumferential side of the attachment part of the flexible member anchored to the stepped part, and the top of the flexible part is placed on the inner surface of the irrigation structure. A flexible joint for an irrigation structure, characterized in that it is exposed and loaded with an irrigation structure frame material.