JPH0144855B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a joint for a cylindrical underground structure constructed underground, and the cylindrical underground structure is used for, for example, a water pipe or a gas pipe. , used to house electric wires, etc.

(Prior art) When cylindrical underground structures are formed of concrete, a joint material such as rubber or asphalt impregnated material is interposed in the joint gap as a joint when connecting the cylindrical underground structures in series. Simple joints that prevent earth and sand and groundwater from entering underground structures are conventionally known. However, with this type of joint, the joint material is always subject to high earth pressure or groundwater pressure, so there is a risk of it separating from the joint gap, so high sealing performance cannot be expected, and it also causes uneven ground settlement,
If the joints of an underground structure shift due to an earthquake, etc., the joint material may come off, or if the joint material is embedded and fixed in the underground structure, the joint material may be cut, causing a large amount of soil and groundwater to leak underground. There is a problem in that they invade structures, making recovery after the fact extremely difficult.

(Object of the invention) The present invention aims to improve the sealing performance of joints for cylindrical underground structures, and in particular, to maintain the sealing performance even in abnormal situations such as earthquakes and uneven ground subsidence. The purpose is to make it possible. In providing such a joint with high sealing performance, the present invention aims to prevent the joint from narrowing the housing space of the cylindrical underground structure or interfering with the contents of the cylindrical underground structure. This is what we are trying to do.

(Structure of the Invention) The joint for a cylindrical underground structure according to the present invention has a sealing plate having a flexible portion in the center, a pair of presser plates, and a bolt as its main components. Both sides of the seal plate are pressed against the inner circumferential surfaces of two cylindrical underground structures facing each other with a gap between them by means of presser plates, and together with the presser plates, bolts are attached to both cylindrical underground structures. is fixed. The flexible portion of the seal plate bulges toward the outer periphery of the cylindrical underground structure in the gap.

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

A cylindrical underground structure 1 is shown in FIG.
This underground structure 1 is made of concrete, and the two underground structures 1, 1 are arranged facing each other with a joint gap 2 between them. Next, this underground structure 1,
The specific structure of the first joint will be explained.

The joint 3 of this embodiment is shown in FIGS. 2 and 3, and includes a seal plate 4, holding plates 5, 5, underlayers 6, 6, and anchor bolts 7, 7. The underground structures 1, 1 have cutout steps 8, 8 formed at the inner circumferential ends of their joints, and these cutout steps 8, 8 have grooves embedded in the underground structures 1, 1. However, the anchor bolts 7, 7 are protruding.

The sealing plate 4 is a rubber sheet with a reinforcing cloth 9 embedded therein, and has a flexible portion 10 in the center, and both sides are flat plate-like, and these both sides have an underlay layer 6 covering the notched step portions 8, 8. , 6. The central flexible portion 10 is located in the joint gap 2 and swells toward the outer circumference of the cylindrical underground structure 1.

The holding plates 5, 5 are both made of metal, plastic,
resin impregnated board, concrete, resin concrete,
It is made of a hard material such as resin mortar or hard rubber, and is applied to both sides of the seal plate 4 from the inside.

The anchor bolt 7 passes through the underlay layer 6, the seal plate 4, and the press plate 5, and the under layer 6, the seal plate 4, and the press plate 5 are formed by applying a nut 11 to the anchor bolt 7 to form a cylindrical shape. It is fixed to underground structure 1. Further, a joint material 12 is interposed in the joint gap 2.

In this case, the underlay layer 6 is the cylindrical underground structure 1
and the seal plate 4, and the seal plate 4 has the function of preventing a gap from forming between the notch step 8 of the cylindrical underground structure 1 and the end face (the end face forming the joint gap 2). It has the function of preventing damage due to direct contact with parts, and is made of an elastic material such as rubber or resin.

In the above-mentioned joint 3, when there is no misalignment between the underground structures 1 and 1, the joint material 12 bears the earth pressure and groundwater pressure, but when the sealing function of the joint material 12 weakens due to aging etc. Earth and sand may enter the joint gap 2. In such a case, the seal plate 4 prevents earth and sand from entering the inside of the underground structure 1.

Even if the two underground structures 1, 1 shift at the joint as shown in FIG. 3 due to uneven ground subsidence, earthquakes, etc., the seal plate 4 has sufficient length at the flexible portion 10. , it is possible to tolerate displacement of the underground structures 1, 1 and avoid breakage. The seal plate 4 prevents earth and sand from entering the underground structure 1. Therefore, gas pipes, water pipes, electric wires, etc. inside the underground structure 1 are not damaged, and restoration work can be carried out from inside the underground structure 1 after the fact.

In addition, as a means for preserving the flexible portion 10 of the seal plate 4 by bending it toward the outer circumferential side of the cylindrical underground structure 1,
A method of pressing the flexible portion 10 by making the opposing ends of the presser plates 5, 5 protrude toward the joint gap 2 side, and a method of pressing the flexible portion 10.
By increasing the amount of deflection of the cylindrical underground structure 1 and expanding it toward the outer circumferential side, the area of the flexible portion 10 that receives earth pressure in the joint gap 2 is increased, and the surface pressure is reduced and the flexible portion 10 is It can be used alone or in combination with a method in which the bent state is maintained by being held between the cylindrical underground structures 1, 1, making it difficult to return to the opposite direction and deform.

Further, in the above embodiment, the reinforcing cloth is embedded in the seal plate, but the reinforcing cloth may not be embedded in the seal plate.

Further, the amount of deflection of the flexible portion of the seal plate can be changed and set as appropriate as necessary.

Further, although the above embodiment relates to a joint for a cylindrical underground structure made of concrete, the present invention can also be applied to underground structures made of steel or plastic by using ordinary bolts instead of anchor bolts.

(Effects of the Invention) According to the present invention, even if two cylindrical underground structures connected to each other are displaced due to uneven subsidence of the ground, earthquake, etc., the seal plate will break because its flexible portion allows for this displacement. This prevents earth and sand from entering into the cylindrical underground structure, and facilitates recovery after the fact.
In addition, since the above-mentioned flexible portion is located in the joint gap and bulges toward the outer circumference of the cylindrical underground structure, it does not reduce the housing space of the cylindrical underground structure or interfere with the contents therein. .

[Brief explanation of drawings]

Figure 1 is a perspective view showing a partial cross section of the underground structure;
FIG. 2 is a longitudinal cross-sectional view showing a joint of the same structure, and FIG. 3 is a cross-sectional view showing the state of the joint in the same structure when an abnormality occurs. DESCRIPTION OF SYMBOLS 1... Underground structure, 2... Joint gap, 3... Joint, 4... Seal plate, 5... Holding plate, 7... Anchor bolt, 10... Flexible portion.

Claims (1)

[Claims] 1. At the joint between two cylindrical underground structures that face each other with a gap, both sides of the seal plate having a flexible part in the center are presser plates on the inner circumferential surface side of both cylindrical underground structures that have a gap between them. 1. A joint for a cylindrical underground structure, characterized in that the seal plate is fixed by a bolt while being pressed against the cylindrical underground structure, and the flexible portion of the seal plate bulges toward the outer periphery of the cylindrical underground structure in the gap.