JPH0545661Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is a cylindrical underground structure buried underground and used for storing water pipes, gas pipes, electric and telephone cables, etc. It relates to the joint structure of structures.

(Prior Art) As the above-mentioned cylindrical underground structure, one having a hollow section with a rectangular cross section for storing water pipes, gas pipes, cables, etc. is known. As a joint structure for connecting objects, a structure has been adopted in which a joint material made of rubber, asphalt impregnated material, etc. is interposed between the ends of cylindrical structures to connect them to each other.

However, in such a joint structure, differences in level may occur due to the joint material being subjected to large earth pressure or water pressure from the outside, or the cylindrical underground structure being affected by uneven ground subsidence or earthquakes. There is a problem in that the joint material separates from the joint of the cylindrical underground structure, and earth and sand and groundwater intrude into the interior of the cylindrical underground structure through this joint.

Therefore, as exemplified in Japanese Patent Publication No. 62-56297, the ends of a cylindrical underground structure having a hollow part with a rectangular cross section are opposed to each other with a gap in between, and the cylindrical underground structure is A joint structure of a cylindrical underground structure has been proposed in which a seal plate having a convex bending part in the center is installed between the inner circumferential surfaces at the ends of the cylindrical underground structure.

Further, as shown in FIGS. 6 and 7, a cylindrical underground structure a is also known in which haunches c are provided at the four corners of an inner circumferential surface b at the end of the cylindrical underground structure a.

(Problem to be solved by the invention) These joint structures are designed to prevent deflection of the seal plate when a level difference occurs in the joint due to uneven ground subsidence or the influence of an earthquake. The part deforms to absorb the difference in level. However, when constructing a seal plate having a bending part protruding inward at the center between the inner circumferential surfaces of the rectangular cross-section, there is a gap between the seal plate and the corner of the inner circumferential surface of the cylindrical underground structure. There is a problem in that it causes

That is, the surface of the corbel c on the inner peripheral surface of the cylindrical underground structure is flat and forms an internal angle with the surfaces on both sides, but the elastic sealing plate is tightly attached to this internal angle without any gaps. It is virtually impossible to do so. For this reason, the gap created between the inner corner of the inner circumferential surface of the cylindrical underground structure and the seal plate sometimes causes water leakage.

In addition, in the cylindrical underground structure shown in FIGS. 6 and 7, the seal plate d including the portion corresponding to the haunch c may be formed in a factory;
Even in this case, there may be a dimensional error or positional deviation between the length of the corbel c of the cylindrical underground structure a and the length of the corresponding part on both sides of the seal plate d, which may cause the corbel c to Seal plates d on the inner corners on both sides
did not come into complete contact with each other, leaving gaps e on both sides of the corbel c, making it impossible to completely prevent water leakage from the joints of the cylindrical underground structure.

In view of the above, the present invention aims to eliminate the gap between the inner circumferential surface and the seal plate at the joint of a cylindrical underground structure, thereby almost completely preventing water leakage from the joint. purpose.

(Means for Solving the Problem) In order to achieve the above-mentioned object, the inventions of claims (1) and (2) provide for each of the four corners of the inner circumferential surface at the end of the cylindrical underground structure to be It is formed into a concave curved surface that is smoothly continuous with the surface.

That is, the solution taken by the invention of claim (1) has a hollow portion with a rectangular cross section, and a corbel with a flat surface forming an internal angle with the surfaces on both sides at each of the four corners of the inner circumferential surface. A cylindrical underground structure is formed in which a large diameter part is formed at the end of the cylindrical underground structure in which the inner peripheral surface expands stepwise outward over the entire circumference, and It is characterized in that each of the four corners of the inner peripheral surface of the large diameter portion is formed into a concave curved surface that smoothly continues with the surfaces on both sides thereof.

Moreover, the means taken by the invention of claim (2) each has a hollow part with a rectangular cross section, and a corbel with a flat surface forming an internal angle with the surfaces on both sides of the hollow part is provided at each of the four corners of the inner circumferential surface. A joint structure of cylindrical underground structures that are formed and lined up in the longitudinal direction of the tubes with gaps between their end faces, wherein each of the opposing ends of the cylindrical underground structure has an inner periphery. A large diameter portion is formed in which the surface expands stepwise outward over the entire circumference, and each of the four corners of the inner peripheral surface of the large diameter portion is formed into a concave curved surface that smoothly continues with the surfaces on both sides thereof. A sealing plate having a flexible portion at the center extends over the entire circumference of the cylindrical underground structure and straddles the gap, with both sides of the sealing plate facing the inner circumferential surface of the large diameter portion of the opposing end. It is characterized by being constructed.

(Function) In each of the means of claims (1) and (2), not only static loads such as earth pressure act on the cylindrical underground structure, but also live loads act on the cylindrical underground structure as vehicles pass over the ground. As a result, a large shearing force acts on the four corners of the hollow portion, but since corbels are provided at these four corners, there is no lack of strength.

Therefore, at the end of the cylindrical underground structure, each of the four corners of the inner peripheral surface is formed into a concave curved surface that smoothly continues with the surfaces on both sides.
The seal plate can be easily fixed to the inner circumferential surface of the end portion of the cylindrical underground structure by aligning it without any gaps.

In other words, even if the seal plate is not formed into a shape that corresponds to the corbel, the seal plate itself can easily be curved into a concave curved surface, so it is possible to mold the seal plate to the inner circumferential surface of the end of the cylindrical underground structure. It is something that can be followed. Furthermore, even in the case of a seal plate that is pre-formed into a shape that corresponds to the corbel, if the inner peripheral surfaces of the four corners are concavely curved, it is easy to absorb the dimensional errors and positional deviations mentioned above. , which can be placed along the inner peripheral surface of the end of the cylindrical underground structure.

Since the concave curved surface is not formed over the entire length of the cylindrical underground structure, there is no problem in ensuring the strength of the cylindrical underground structure, and it is also easy to form the corbel. Since there is no need to use a special formwork with a curved surface, the cylindrical underground structure is easy to manufacture and the manufacturing cost does not increase. Furthermore, since the inner circumferential surface of the end portion is formed into a large diameter portion that expands stepwise outward over its entire circumference, even if the seal plate is erected, the seal plate will not fit into the cylindrical underground structure. It does not protrude inside objects.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

1 and 2 show a cylindrical underground structure A made of concrete according to an embodiment of the present invention, and FIGS. 3 and 4 show a joint structure of the cylindrical underground structure A. This cylindrical underground structure A is buried underground, and by connecting, for example, about 10 pieces in the axial direction, a common ditch is formed for storing water pipes, gas pipes, telephone and electric cables, etc. It shows the case.

Connecting holes 1 extending through the axial direction are provided at the four corners of the underground structure A, and a PC steel rod is inserted through the connecting holes 1 of each connected cylindrical underground structure A. Further, by applying tension to the PC steel rod, the cylindrical underground structures A are tightly connected to each other.

In this case, as shown in FIG. 4, a joint material 2 made of rubber or asphalt impregnated material is fitted between the opposing ends of the cylindrical underground structure A. This joint material 2 forms a gap 3 between the cylindrical underground structures A, and is compressed between the cylindrical underground structures A by the tension of the PC steel rod, so that earth pressure or groundwater Cylindrical underground structure A from pressure
protects the inside of

The cylindrical underground structure A has, for example, a square cross section with a side of about 2.1 m and a hollow part 4 extending in the axial direction. is provided with a corbel 6 having a flat surface and having a width of about 0.21 m, for example, which extends in the axial direction and forms an internal angle with the surfaces on both sides thereof.

Further, the inner peripheral surface 5 at both ends of the cylindrical underground structure A is provided with a large diameter part 7 in which the hollow part 4 expands stepwise, and each of the four corners of this large diameter part 7 has, for example, A concave curved surface portion 8 with R=approximately 0.2 to 0.4 m is formed, and this concave curved surface portion 8 is smoothly continuous with the surfaces on both sides thereof.

As shown in FIG. 4, anchor bolts 9 are buried in the inner circumferential surface 7a of the large diameter portion 7 of the cylindrical underground structure A at predetermined pitches. Both sides of the sealing plate 10 are fixed via band-shaped retaining plates 11, thereby forming a convex flexible portion 10a in the center between the inner circumferential surfaces 5 at the ends of the cylindrical underground structure A. A seal plate 10 having a structure is installed.

The seal plate 10 is made of an elastic material such as rubber, and can deform itself to absorb the difference in level when a difference in level occurs between the cylindrical underground structures A on both sides. Furthermore, a reinforcing cloth 10b is embedded inside the seal plate 10, making it difficult to break even if the seal plate 10 is deformed. Furthermore, the presser plate 11 is made of metal,
The both sides 10c of the sealing plate 10 are connected to a cylindrical structure A, which is a band-shaped material made of plastic, hard rubber, etc.
It is pressed against the inner circumferential surface of the large diameter portion 7 of.

As described above, each of the four corners of the inner circumferential surface 7a of the large diameter portion 7 of the cylindrical structure A is provided with a concave curved surface portion 8 that smoothly continues with the surfaces on both sides thereof, so that the seal plate 10 Although the seal plate 10 has a convex flexible portion 10a at the center, both side portions 10c of the seal plate 10 can be curved along the concave curved surface portion 6. Therefore, although the cross-sectional shape of the hollow portion 4 is square, the inner circumferential surface 7a of the large diameter portion 7 and both side portions 10 of the seal plate 10
There is no gap between the cylindrical underground structure A and the cylindrical underground structure A, and groundwater etc. hardly enter into the inside of the cylindrical underground structure A.

As shown in FIG. 4, the hollow part 4 of the seal plate 10
On the side, a filler material 13 such as resin mortar or cement mortar is placed on the upper part of the presser plates 11 on both sides, and an elastic material 12 made of rubber or the like is placed in the center. The inner circumferential surface 5 of No. 4 is formed to be substantially flush with each other. In addition,
These filler material 13 and elastic material 12 can also be omitted.

FIG. 5 shows a modification of the joint structure of a cylindrical underground structure, in which a metal pedestal plate 14 having an L-shaped cross section is disposed on the inner circumferential surface 7a of the large diameter section 7. The shape of the inner circumferential surface 7a of 7 is adjusted.

The cylindrical underground structure A may be manufactured in advance at a factory and transported to the site, or may be poured at the site.

Furthermore, although the shape of the flexible portion 10a of the seal plate 10 is convex, the shape is not limited to this, and may be a convex shape having a concave portion at the tip, or a concave shape.

(Effect of the invention) As explained above, according to the inventions of claims (1) and (2), at the end of a cylindrical underground structure having corbels with a flat surface at the four corners, Each of the cylindrical underground structures is formed into a concave curved surface that smoothly continues with the surfaces on both sides, so that while the corbels ensure the strength of the cylindrical underground structure, the sealing plate has a flexible portion in the center. Also, both sides of the seal plate can be easily curved and brought into close contact with the inner peripheral surface of the cylindrical structure, and the gap between the inner peripheral surface and both sides of the seal plate at the end of the cylindrical structure can be easily curved and brought into close contact with each other. By eliminating gaps, water leakage from the joints of the cylindrical structure can be almost completely prevented.

Further, according to the inventions of claims (1) and (2), it is easy to manufacture corbels for cylindrical underground structures, and
The seal plate itself can be manufactured at low cost without using a special mold to fit along the corbel, and furthermore, the seal plate does not protrude into the interior of the cylindrical underground structure.

[Brief explanation of the drawing]

Figures 1 and 2 show an example of a cylindrical underground structure, with Figure 1 being a side view, Figure 2 being a perspective view, and Figure 3 being a perspective view.
4 and 4 show an example of the joint structure of a cylindrical underground structure, FIG. 3 is a sectional view, FIG. 4 is a sectional view taken along the line - in FIG. 3, and FIG. 5 is a cylindrical underground structure. Partial sectional view showing a modified example of the joint structure of an object, No. 6
The figure is a side view of a conventional cylindrical underground structure, and FIG. 7 is a partial sectional view of the joint structure of the conventional cylindrical underground structure. A... Cylindrical underground structure, 3... Gap, 4... Hollow part, 5... Inner circumferential surface, 7... Large diameter part, 7a... Inner circumferential surface, 8... Concave curved surface part, 10... ...Seal plate, 10
a... Flexible part, 10c... Side part.

Claims (1)

[Claims for Utility Model Registration] (1) A cylinder that has a hollow portion with a rectangular cross section and has a flat-surfaced haunch formed at each of the four corners of the inner circumferential surface to form an inner angle with the surfaces on both sides thereof. A cylindrical underground structure, in which a large diameter part is formed at the end of the cylindrical underground structure, the inner peripheral surface of which expands stepwise outward over the entire circumference, and the inner circumference of the large diameter part is A cylindrical underground structure characterized in that each of the four corners of the circumferential surface is formed into a concave curved surface that smoothly continues with the surfaces on both sides. (2) Each has a hollow part with a rectangular cross section, and a haunch with a flat surface that forms an internal angle with the surfaces on both sides is formed at each of the four corners of the inner circumferential surface, with a gap between the end faces. A joint structure of cylindrical underground structures lined up in the longitudinal direction of the tubes, wherein each of the opposing ends of the cylindrical underground structure has an inner circumferential surface stepped outward over its entire circumference. A seal in which a large diameter part is formed that is enlarged to 1, and each of the four corners of the inner circumferential surface of the large diameter part is formed into a concave curved surface that smoothly continues with the surfaces on both sides thereof, and has a flexible part in the center part. A cylindrical underground structure characterized in that the plate spans the gap over the entire circumference of the cylindrical underground structure, and both sides of the seal plate are installed on the inner peripheral surface of the large diameter portion of the opposing end. Joint structure of structures.