JPH0144856B2 - - 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 basic object of the present invention is to improve the sealing performance of a joint for a cylindrical underground structure.
In particular, it is possible to ensure sealing performance even in the event of an abnormality such as an earthquake or uneven ground subsidence. The present invention makes it possible to provide such a joint with high sealing performance at a low cost.

(Structure of the Invention) The joint for a cylindrical underground structure according to the present invention has two seal plates, a pair of holding plates, and a side plate as main components. The two seal plates, that is, the first seal plate and the second seal plate, are stacked on both sides of each seal plate on the inner peripheral surface side of the opposing cylindrical underground structure across the joint gap. A flexible portion is provided at the center of the second seal plate and bulges inward of the cylindrical underground structure. On the other hand, both of the holding plates are stacked on both sides of the second seal plate, and these both sealing plates and the holding plate are fixed to the cylindrical underground structure with bolts.

A side plate protruding inward from the cylindrical underground structure is provided at a position on the side of the joint gap between both holding plates, and the flexible portion of the second seal plate is located between both side plates.

(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.

Example 1 The joint 3 shown in FIGS. 2 and 3 has a first seal plate 4, a second seal plate 5, presser plates 6, 6, anchor bolts 7, 7, and side plates 14, 14 as main components. . 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. Further, rubber seal layers 9, 9 are formed on the notch step portions 8, 8 by applying a liquid rubber seal material. After the anchor bolt 7 has a notch step, a mounting hole may be formed in the notch step and the anchor bolt 7 may be fixed in the mounting hole.

The first seal plate 4 and the second seal plate 5 are both rubber sheets in which reinforcing cloths 10 and 11 are embedded. The first seal plate 4 has notched step portions 8, 8 on both sides with a slight flexure 12 provided at the position of the joint gap 2.
The rubber seal layers 9, 9 are overlapped and bonded to each other.
The second seal plate 5 has a flexible portion 13 that bulges largely inward of the cylindrical underground structure 1 at the center thereof, and both sides of the second seal plate 5 are overlapped with both sides of the first seal plate 4.

The holding plates 6, 6 are made of a hard material such as metal, plastic, resin-impregnated plate, cement concrete, resin concrete, resin mortar, etc., or hard rubber, and the one in this example is made of a steel plate.
Both sides of the second seal plate 5 are applied from inside the underground structure 1. Side plates 14, 14 protruding inward from the underground structure 1 are welded to the ends of the holding plates 6, 6 on the side of the joint gap 2, with the lower portions bent into an L-shape. The flexible portion 13 of the second seal plate 5 is interposed between the plates 14, 14.

The anchor bolt 7 passes through both the seal plates 4, 5 and the retainer plate 6, and both the seal plates 4, 5 and the retainer plate 6 pass through the anchor bolt 7 with the nut 1.
5 is applied to the underground structure 1. Then, a covering layer 16 is formed by pouring a casting material such as resin mortar into the recess formed by the side surface of the cutout step 8 of the underground structure 1, the holding plate 6, and the side plate 14. The surface of the covering layer 16 is flush with the inner peripheral surface of the underground structure 1. Further, a joint material 17 is interposed in the joint gap 2.

In the above-mentioned joint 3, when there is no deviation between the underground structures 1 and 1, the joint material 17 bears the earth pressure and groundwater pressure, but when the sealing function of the joint material 17 becomes weak due to aging etc. Earth and sand may enter the joint gap 2. In such a case, the first seal plate 4 prevents earth and sand from entering the inside of the underground structure 1. Further, a rubber seal layer 9 is provided between the first seal plate 4 and the notch step 8, and with this rubber seal layer 9 filling the unevenness of the notch step 8, the first seal plate 4 is attached to the notch step 8. Since the first seal plate 4 and the cutout step 8 are in close contact with each other, there is no intrusion of groundwater from between the first seal plate 4 and the cutout step portion 8.

Further, the side plates 14, 14 have a function of preventing the deformation of the flexible portion 13 of the second seal plate 5, and
The second seal plate 5 protects the flexible part 13 by preventing it from coming into contact with machines, tools, etc. and preventing damage to the flexible part 13 during work such as piping inside. 13 is protected by the first seal plate 4 and the side plates 14, 14 and maintains its original state when installed. In addition, when forming the covering layer 16 as in this embodiment, the side plate 14 serves as a formwork when pouring a pouring material such as resin mortar, and also serves as a formwork for bonding the pouring material and the second seal plate 5. This prevents the second seal plate 5 from being damaged and allows the second seal plate 5 to fully perform its sealing function in the event of an abnormality as described below.

That is, in an abnormal situation where two underground structures 1, 1 shift at the joint as shown in FIG. 3 due to uneven subsidence of the ground, earthquake, etc., the first seal plate 4 breaks, but the second seal plate 5 bends. Since there is enough length in the portion 13, it will not break. Since the flexible portion 13 of the second seal plate 5 is not adhered to the coating layer 16, there is no problem of damage caused by peeling off from the coating layer 16, and even if it is directly exposed to high earth pressure, it will not break. Withstands earth pressure. In other words, the second seal plate 5 prevents dirt and the like 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 after the fact.

Example 2 A joint 21 shown in FIG. 4 differs from Example 1 in the configurations of the second seal plate 22 and side plates 23.

The second seal plate 22 is composed of a rubber seal with a reinforcing cloth 11 embedded therein, and a flexible portion 24 is formed in a W-shape to have a greater amount of deflection than that of the first embodiment. The side plate 23 has an extension part 25 at its tip that is bent and extended toward the joint gap side so as to cover the side surface of the flexible part 24 and the two bent top parts. This extending portion 25 has a function of holding the flexible portion 24 in a bent state.

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.

In addition, the amount of deflection of the flexible portion of the second seal plate can be changed and set as necessary.

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

In addition, although the coating layer 16 was provided in the above embodiment,
This covering layer 16 may be omitted.

Furthermore, when the presser plate is made of metal, the side plate can be welded to the presser plate in advance, or it can be welded on site. Regardless of whether the holding plate is made of metal or non-metal, the side plate can be fixed to the holding plate with ordinary head bolts or anchor bolts, and furthermore, the holding plate and the second seal plate can be fixed to the holding plate. It is also possible to adopt a fixing method in which the base of the side plate is sandwiched between the presser plate and the side plate, or a method in which the presser plate and the side plate are integrally molded from the same material.

(Effects of the Invention) According to the present invention, even if a displacement occurs in the connected cylindrical underground structure due to uneven subsidence of the ground, earthquake, etc., the second seal plate allows this displacement at the flexible portion. It does not break and prevents earth and sand from entering into the cylindrical underground structure, making subsequent restoration easier. In addition, since the side plate protects the flexible part of the second seal plate by keeping it in a flexible state, this flexible part is kept in the state it was in when it was installed, and it can fully perform its sealing function without breaking in the event of an abnormality. Furthermore, the side plate can also serve as a formwork when a coating layer is provided on the holding plate.

[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 in Example 1 with some parts omitted, FIG. 3 is a cross-sectional view showing the state of the joint in the same example in the event of an abnormality, and FIG. It is a longitudinal cross-sectional view showing a joint with a portion omitted. 1... Cylindrical underground structure, 2... Joint gap, 3,
21... Joint, 4... First seal plate, 5, 22...
... Second seal plate, 6 ... Holding plate, 7 ... Anchor bolt, 13, 24 ... Flexible part, 14, 23 ...
side plate.

Claims (1)

[Claims] 1. At the joint between two cylindrical underground structures that face each other with a gap in between, both sides of each of the first seal plate and the second seal plate are attached to the inner peripheral surfaces of both cylindrical underground structures across the gap. The first seal plate, the second seal plate, and the press plate are fixed to the cylindrical underground structure with bolts, and the first seal plate, the second seal plate, and the press plate are fixed to the cylindrical underground structure with bolts. Side plates protruding inward from the cylindrical underground structure are provided on the gap sides of both holding plates, and a flexible portion bulging inward from the cylindrical underground structure is provided at the center of the second sealing plate. A joint for a cylindrical underground structure, characterized in that the flexible portion is located between the both side plates.