JPS5824575B2 - culvert joint - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to joints for underdrains used in water supply and sewerage systems, public ditches, underground passages, etc., and is used to prevent damage from earth and sand and boulders in flowing water in underdrains, and to prevent harmful strain and stress concentration. This invention relates to an underdrain joint that prevents the occurrence of such occurrences, improves durability, and improves the ability to follow relative displacement between a pair of underdrains to be connected.

In general, for culverts such as water and sewage systems, underground passages, and public ditches that are buried in soft reclaimed land or ground with changing strata,
Uneven subsidence and relative displacement of the ground can cause cracks and water leakage in the underdrain structure, and in some cases, the underdrain structure itself can be damaged. To prevent this, flexible joints are installed at key points. Measures are being taken to connect culverts.

Conventional flexible joints for underdrains simply connect both ends of a cylindrical flexible member made of an elastic material such as rubber or synthetic resin or a deformable material such as a thin iron plate or thin copper plate to the concrete frame of the underdrain opening facing each other. A cylindrical flexible member is installed along the inner circumferential surface of the culvert opening, spanning both culverts, and both ends are anchored to the concrete frame.

However, a joint in which both ends of a cylindrical flexible member are simply buried and fixed in a concrete frame has the problem that it cannot follow large relative displacements between opposing underdrains, and If a joint has a flexible member straddled along the culvert, the flexible member may protrude inside the culvert due to external water pressure such as groundwater or earth pressure, reducing durability, or when used in a culvert with running water. There were problems such as damage caused by pieces of iron, wood, and boulders in the flowing water.

In order to solve these problems, the present invention uses a flexible member having a flexible section with a corrugated cross section in order to absorb the large relative displacement of the underdrain to be connected. It is an object of the present invention to provide a joint for an underdrain in which a flexible member is built into the center of the body of the underdrain and is straddled to prevent damage to the flexible member.

Furthermore, in order to suppress the occurrence of harmful strain and stress concentration in the flexible member and improve durability, the flexible member is formed with a flexible portion having a corrugated cross section, and the flexible member is formed with a flexible portion having a corrugated cross section. The object of the present invention is to provide a joint for an underdrain in which a gap is formed between the wave-shaped cross section of the flexible member and the underdrain frame in order to improve followability to relative displacement.

The present invention is characterized in that a flexible member storage space is formed at the center position in the thickness direction of the mutually opposing end faces of the underdrain bodies of a pair of underdrains to be connected, and a flexible member storage space is formed between the flexible member storage spaces. The structure consists in straddling the members while leaving a gap that allows the flexible members to be displaced.

An embodiment of the underdrain joint of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 and 1' indicate a pair of underdrains to be connected.

Although the illustrated example shows a culvert with a rectangular cross section, the cross-sectional shape is not limited to this, and may be other shapes, such as a circle, a bow shape, or a polygon.

In addition, although the culvert is shown as being made of concrete, it may also be a segment-connected type culvert, an integral cylindrical type steel culvert, or the like.

In this case, between the underdrains 1 and 1', a means such as an auxiliary segment (shown path) or the like to facilitate the installation of the underdrain joint may be installed as necessary. Interventions may be used.

Flexible member storage spaces extending in the circumferential direction are formed at the center positions in the thickness direction of the mutually opposing end faces of the underdrains 1 and 1', and between the flexible member storage spaces, rubber, synthetic resin, etc. A cylindrical flexible member 2 made of an elastic material such as
Among them, joint materials 3 and 4 are filled at the outer peripheral position.

Figure 2 shows a cross section of a joint for a culvert, and since the joint has a symmetrical structure in the axial direction, one member will be mainly explained, and the other member will be explained using the one member mentioned above. By adding a dash to the reference numeral, redundant explanation thereof will be omitted as necessary.

In FIG. 2, the flexible member 2 is installed so as to straddle the ends of each of the underdrains 1 and 1', and is housed in the underdrain body at the center of the body.

The flexible portion 2 includes a flexible portion 2a having a wave-shaped cross section and the flexible portion 2.
The mounting portion 2b is integrally connected to both ends of the mounting portion 2a.

In this embodiment, the flexible portion 2a has a main flexible portion 2a-1 having a large wave-shaped cross section, and is integrally connected to both ends of the main flexible portion 2a-1, and has a larger wave-shaped cross section than the main flexible portion 2a-1. Although the auxiliary flexible portion 2a-2 having a small corrugated cross section is shown in the figure, the iSM is not included in this, and for example, all the same flexible portions 2a are formed from the same corrugated cross section. Good too.

A bolt insertion hole 2c is bored in the center of the attachment part 2b, and a retaining protrusion 2d for preventing removal is provided at the end of the attachment part 2b.

An anchoring member 5 made of iron material, synthetic resin, etc. is fixed to the underdrain 1 at the position of the attachment part 2b of the flexible member 2 within the culvert 1 body, and the anchoring member 5 is fixed with a bolt or an anchor bolt. 6 is fixed.

A backing plate 1 made of iron, synthetic resin, or the like is provided at a position facing the anchoring member 5.

The mounting portion 2b of the flexible member 2 is held between the anchoring member 5 and the plate γ, and is tightened by screwing a nut 8 onto a bolt or anchor bolt 6 that passes through the mounting portion 2b and the plate γ. As a result, it is firmly fixed to the anchoring member 5.

Further, the bolts or anchor bolts 6 are welded to the reinforcing bars 9 as necessary.

The attachment of the flexible member 2 to the underdrains 1, 1' is not limited to the above-mentioned method, but any other method may be used as long as the flexible member 2 can be attached to the underdrains 1, 1' with water-stop properties. It may be the structure of

Further, a frame plate 10 made of iron, urethane, synthetic resin, etc. for sliding when the flexible member 2 is deformed is fixed to the culvert 1 with its surface aligned with the surface of the support plate 1.

However, this frame plate 10 does not necessarily have to be provided, and the surface in contact with the flexible member 2 may be formed from the underdrain body itself.

In the state configured as above, an underdrain 1 is installed around the flexible member 2.
Concrete, mortar, etc. that form part of the concrete are poured.

In this case, the outer periphery of the flexible part 2a of the flexible member 2 is filled with concrete, mortar, etc. so as to be in contact with the surface of the flexible member 2, but the inner periphery of the flexible part 2a is filled with concrete, mortar, etc. A gap 1 is formed between the concave surface of the wave-shaped cross section of the flexible portion 2a and the underdrain body 1.
1 or 2 is formed.

In addition, a joint material made of sponge rubber, soft rubber, etc. is inserted into a recess formed on the outer periphery of the flexible portion 2a.
The deformation ability of a may be prevented from decreasing.

In addition, instead of pouring concrete, mortar, etc., as described above, for example, the underdrain body on the outer circumferential side, which is made of a plate-shaped body with an inner surface shape that follows the outer circumferential surface of the flexible member 2, and the inner circumferential side of the flexible member 2, A flexible member 2 is interposed and installed between the underdrain body 1 on the inner peripheral side, and a gap 11 is formed between the concave surface of the wave-shaped cross section of the flexible portion 2a of the flexible member 2 and the underdrain body 1. Of course, the flexible member 2 may be attached to the underdrain frame with the gap 11 left between the concave surface of the wave-shaped cross section of the flexible portion 2a and the underdrain frame 1 (not shown). 1. It is sufficient if it is built in the center position and straddled.

The joint materials 3 and 4 interposed between the end faces of the underdrains 1 and 1' and at the inner and outer circumferential positions of the flexible member 2 prevent dirt and boulders from entering the flexible member 2 in the flowing water of the underculvert 1. In addition to preventing
It is provided to reduce the resistance of water flowing inside the culvert 1, and is made of, for example, rubber, sponge rubber, asphalt, putty, etc.

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

FIG. 2 shows the state before any relative displacement occurs between the underdrains 1 and 1'.

In this state, the flexible member 2 is built in between the culverts 1 and 1', and its inner and outer peripheries are protected by the joint materials 3 and 4, so that the flexible member 2 is free from dirt and debris inside the culvert 1. The flexible member 2 is not exposed to boulders or the like in running water, and no damage occurs to the flexible member 2.

Furthermore, when an external pressure load such as groundwater or earth and sand or an internal pressure load such as running water in a culvert acts strongly, the joint materials 3 and 4 may be pushed inward or outward and push the flexible member 2.

However, when it is pushed inward, the distance l between the outer surfaces of the part of the main flexible part 2a-1 that pinches the joint material 4 is the gap between the underdrains 1 and 1' because it is sandwiching the joint material 4. Since the spacing is twice as large as the thickness m of the main flexible portion 2a-1, the flexible member 2 will not penetrate between the underdrains 1 and 1' and bulge out into the inner surface of the underdrains 1. Deformation or harmful strain is prevented from occurring.

Conversely, when pushed outward, this load is applied to the main flexible portion 2a.
-1 is supported by the surface of the underdrain 1 body which is in contact with the convex side of the main flexible part 2a-1 through the underdrain 1, and the flexible member 2 is not significantly deformed or harmful strain is caused to the flexible member 2. .

In addition, the main flexible portion 2a-
Even if slight deformation or distortion occurs in the main flexible part 2a-1, the auxiliary flexible part 2a-2 is connected to the main flexible part 2a-1, and the auxiliary flexible part 2a-1 and the auxiliary flexible part Since the cavity 11 is formed on the concave side of 2a-2, the flexible part 2a formed from the main flexible part 2a-1 and the auxiliary flexible part 2a-2 deforms easily, and the mounting part Flexible member 2 including 2b
No unreasonable strain or stress concentration will occur.

This significantly improves the durability of the flexible member 2.

FIG. 3 shows a case where a relative displacement occurs between the underdrains 1 and 1' in a direction perpendicular to the joint direction.

Even in this state, the flexible member 2 has the main flexible portion 2a-1 with a large wave-shaped cross section, and the auxiliary flexible portion 2a-2 with a small wave-shaped cross section is also secondary. Because it has this feature, it can follow large relative displacements and absorb relative displacements while maintaining a sound water-stopping function.

It should be noted that even if a relative displacement occurs between the underdrains 1 and 1' in the direction parallel to the joint axis direction, the main flexible section 2a-1 and secondarily the auxiliary flexible section 2a-2 can absorb the relative displacement. Not until now.

A large relative displacement as shown in FIG.
1 and the auxiliary flexible portion 2a-2 can be smoothly deformed due to the existence of the void portion 11, so that they can be absorbed smoothly.

Furthermore, even if the main flexible section 2a-1 undergoes a large deformation, since the auxiliary flexible section 2a-2 is connected to the main flexible section 2a-1, the auxiliary flexible section 2a-2 will Since the flexible member 2 including the attachment portion 2b is deformed smoothly using the portion 11, no unreasonable strain or stress concentration occurs in the flexible member 2 including the attachment portion 2b.

That is, even in this state, the soundness and durability of the flexible member 2 are maintained.

Furthermore, even if a large relative displacement as shown in FIG. 3 occurs, only a small portion of the flexible member 2 with a built-in underdrain is exposed to the earth and sand and running water in the underdrain, so the flexible member 2
There is little risk of damage to the culvert from dirt or boulders in the flowing water inside the culvert.

In this embodiment, the flexible portion 2a includes a main flexible portion 2a-1 having a large wavy cross section and an auxiliary flexible portion 2a having a small wavy cross section integrally connected to the main flexible portion 2a-1.
If the flexible portion 2a has a corrugated cross section, the same effect as above can be expected, and if the flexible portion 2a has a corrugated cross section, the same effect as above can be expected. Of course, it is also possible to use something made of other materials.

Therefore, when using the underdrain joint of the present invention, a flexible member storage space extending in the circumferential direction is formed at the center position in the thickness direction of the opposing underdrain frame end surfaces of a pair of underdrains to be connected,
a rubber having a flexible section with a corrugated cross section spanning between the spaces;
A cylindrical flexible member made of synthetic resin is installed across the conduit, and a gap is formed between the concave side of the corrugated cross section and the underdrain body, so even if a large relative displacement occurs between the underdrains, it can be easily followed. This allows the relative displacement to be smoothly absorbed.

Further, the flexible member is formed of a main flexible part having a large wave-shaped cross section and an auxiliary flexible part having a small wave-shaped cross section integrally connected to the main flexible part, and the auxiliary flexible part. When configured with an integrally connected mounting section, even if a large relative displacement occurs between the underdrains and a large deformation occurs in the main flexible section, the auxiliary flexible section will act as a buffer, and the flexible section, including the mounting section, will It is possible to prevent excessive strain and stress concentration from occurring in the member.

This can significantly improve the durability of the joint.

Furthermore, since the flexible member is built into the center of the culvert and is placed across both culverts, the flexible member is not exposed to earth and sand or boulders in the flowing water within the culvert, and even if there is a large distance between the culverts, Since the flexible member is hardly exposed even if it is displaced, it is possible to prevent damage to the flexible member due to earth and sand or boulders in the flowing water in the culvert.

In addition, by incorporating a flexible member in the center of the underdrain frame, even if internal or external pressure loads are applied to the flexible member, the flexible member will not bulge in or out of the underdrain under normal conditions, improving pressure resistance. In addition, it is possible to prevent the flexible member from being damaged by bulging in and out of the culvert.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a culvert equipped with the culvert joint of the present invention, and Figure 2 is a sectional view taken along the line ■-■ in Figure 1, showing the state before relative displacement occurs between the culverts. A cross-sectional view, Figure 3 is a cross-sectional view of the state after relative displacement has occurred between the culverts in Figure 2,
It is. 1.1'...Drainage, 2...Flexible member,
2a...Flexible part, 2a-1, 2a-1'...
...Main flexible part, 2a-2, 2a-2'...Auxiliary flexible part, 2b, 2b'...Mounting part,
11, 11'...Void portion.

Claims (1)

[Claims] 1. A flexible member storage space extending in the circumferential direction is formed at the center position in the thickness direction of the mutually opposing end faces of the underdrain frames of a pair of underdrains to be connected, and a flexible member storage space is formed between the flexible member storage spaces. , a cylindrical flexible member made of rubber/synthetic resin having a flexible section having a corrugated cross section and mounting sections integrally connected to both ends of the flexible section, is connected to the corrugated cross section of the flexible section and the underdrain frame. A joint for an underdrain characterized by being built over the underdrain with a gap left in between and built into the underdrain frame. 2. In the joint for a culvert according to claim 1, the flexible member includes a main flexible part having a large wavy cross section and an auxiliary flexible part having a small wavy cross section connected to the main flexible part. and a mounting part integrally connected to the auxiliary flexible part,
A space is left between the corrugated cross section of the main flexible part and the auxiliary flexible part and the underdrain body, and the mounting part is embedded in the underdrain body.