JPH07229389A - Cushion body for propulsive construction method - Google Patents

Abstract

PURPOSE:To ensure the proper transmission of a propelling force, diverge compressive stress acting on the joint of a curved section and prevent the ingress of sediment from the joint by externally coupling a cushion body to the outer surface of the insertion hole of a trailing tube. CONSTITUTION:A cushion body 31 is externally coupled to the outer surface of an insertion hole 4, with the first and second sediment ingress prevention cushion sections 34 and 35 directed toward the inside and outside of the curvature of the curved section of a buried pipe line. In this case, the first or second sediment ingress prevention cushion section 34 or 35 is well compressed at the inside of the curvature, and compressive stress generated on the flange 5 of a trailing pipe 3 as well as on the forward edge of the socket 2 of a leading pipe 1 is diverged over a wide range. Furthermore, a propelling force is properly transmitted from the flange 5 of the trailing pipe 3 to the socket 2 of the leading pipe 1 via the first and second propelling force transmission cushion sections 32 and 32 of the cushion body 31. On the other hand, the first or second sediment ingress prevention section 34 or 35 well elongates at the outside of the curvature, and keeps the state of close contact with the flange 5 and the socket 2, thereby preventing the ingress of sediment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushion body provided at a joint portion between a leading pipe and a trailing pipe for a propulsion method.

[0002]

2. Description of the Related Art Conventionally, in a propulsion method, a starting pit and a reaching pit are formed at an appropriate distance on a route to be buried and a pipe for the propulsion method is installed on a guide rail in the starting pit. Is mounted, and a hydraulic jack and a required number of spacers are interposed between a backing plate arranged at the rear end thereof and a reaction plate. Then, by operating the hydraulic jack in this state, the propulsion method pipe is pushed into the soil along the laying route. After that, the operation of the hydraulic jack and the addition of spacers are repeated to push the propulsion method pipe into the soil one after another, and when almost the entire length of the propulsion method pipe is pushed into the soil, the subsequent propulsion method pipe is inserted into the start pit. And is connected to the preceding propulsion method pipe, and the same operation as described above is repeated thereafter to lay a buried pipeline to which the propulsion method pipe is connected.

In the joint portion of the pipe for the propulsion method, as shown in FIG. 4, a receiving port 2 is formed at the rear end of the preceding pipe 1 and an insertion port 4 is formed at the front end of the succeeding pipe 3. There is. A flange 5 is provided on the outer circumference of the insertion port 4 to transmit the propulsive force by making surface contact with the tip surface of the reception port 2 when the insertion port 4 is inserted into the reception port 2.

The flange 5 is reinforced by a plurality of ribs 6. Further, the outer peripheral surface of the insertion port 4 and the inner peripheral surface of the receiving port 2 are sealed with a sealing material 7. Mortar layers 8 are formed on the outer circumferences of the preceding pipe 1 and the succeeding pipe 3, respectively.

According to this, the propulsive force is transmitted from the flange 5 of the succeeding pipe 3 to the tip surface of the receiving port 2 of the preceding pipe 1,
The trailing pipe 3 and the leading pipe 1 are pushed into the soil and propelled toward the reaching pit.

[0006]

However, when the buried conduit 9 moves from the first straight line portion 10 to the second straight line portion 12 via the curved line portion 11 as shown in FIG. 5, as shown in FIG. On the inside of the bend of the curved portion 11, there arises a problem that the compressive stress concentrates on the contact portion between the flange 5 and the tip surface of the receiving port 2 and the allowable resistance becomes small, and on the outside of the bend,
A gap 14 is formed between the flange 5 and the tip surface of the receiving port 2, and a problem arises in that earth and sand flow into the gap 14 and the joint portion comes out.

In order to solve the problem of stress concentration as described above, an annular cushion body as shown in FIGS. 6 and 7 is used.
It was conceived that the 15 was externally fitted to the insertion opening 4 and attached between the flange 5 and the tip surface of the receiving opening 2. This cushion body 15
Is formed of a uniform material, and the front and back surfaces of the cushion body 15 are formed flat so as to contact almost the entire front end surface of the flange 5 and the front end surface of the receptacle 2. By providing the cushion body 15 as described above, stress concentration is relieved when the pipes 1 and 3 have a small diameter or when the curved portion 11 has a small bending angle, but when the pipes 1 and 3 have a large diameter. When the bending angle of the curved portion 11 is large, even if the cushion body 15 is provided, the compressive stress is not dispersed in a wide range and the allowable resistance does not improve so much.

As to the problem that a gap 14 is formed between the flange 5 and the tip surface of the receiving port 2 outside the bend of the curved portion 11, as shown in FIG.
It is conceivable to attach the to the tip surface of the receiving port 2. That is, the earth and sand inflow prevention plate 16 includes an annular member 18 that is attached and fixed to the front end surface of the receiving port 2 via a plurality of bolts 17, and a flange 5 of the insertion port 4 that is provided on the annular member 18. It is composed of a cylindrical covering member 19 covering the outer peripheral side.

According to this, even if a gap 14 is formed between the flange 5 and the annular member 18 on the outer side of the bend of the curved portion 11, the covering member 19 covers the gap 14. Inflow is prevented.

However, the earth and sand inflow prevention plate 16 is
There is a problem that it becomes very expensive and it takes time to install. Further, the outer peripheral surface of the covering member 19 is the receptacle 2
Since the covering member 19 may be caught when the pipes 1 and 3 are pushed into the soil when the pipes 1 and 3 project outward from the outer peripheral surface of the, the outer diameter of the earth and sand inflow prevention plate 16 is set to the outer diameter of the receiving port 2. Since it is necessary to form them in the same size, it is necessary to reduce the outer diameter of the flange 5 and the rib 6 by the thickness of the covering member 19, and it takes time and cost to change the outer diameter. There was a problem.

The present invention solves the above-mentioned problems, and it is possible to disperse the compressive stress generated in the joint portion in a wide range even when the diameter of the pipe is large or the bending angle of the curved portion is large, and An object of the present invention is to provide a cushion body which can prevent the inflow of earth and sand from the joint portion and can be easily attached at low cost.

[0012]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention is attached to the tip end surface of the receptacle of the leading pipe for the propulsion method and the outer circumference of the receptacle of the trailing pipe, and is inserted into the receptacle. An annular cushion body that is externally fitted to a portion of the insertion opening between the flange that opposes the tip end surface of the receiving opening and transmits the propulsion force when the opening is inserted. And a second cushion portion and first and second cushion portions for preventing sediment inflow, and the cushion portions for transmitting the propulsive force and the cushion portions for preventing sediment inflow are alternately arranged in the circumferential direction. The first and second cushion portions for transmitting the propulsive force are formed of a resin material having a hardness necessary for transmitting the propulsive force, and the first and second cushion portions for preventing the inflow of sediment are expanded and contracted. It is made of a flexible elastic material.

[0013]

According to the above construction, the cushion body is fitted onto the insertion opening with the first and second cushion portions for preventing the inflow of sediment directed toward the inside and outside of the bend of the curved portion of the buried pipeline. . As a result, the space between the flange and the tip surface of the receiving port is reduced on the inner side of the bend of the curved portion. In response to this, the first or second portion for preventing the inflow of earth and sand of the cushion body.
Since either one of the cushions is sufficiently compressed, it occurs on the flange inside the bend and the tip surface of the receiving port even when the pipe diameter is large or the bending angle of the curved part is large. The compressive stress is widely dispersed. At this time, the propulsive force is reliably transmitted from the flange of the subsequent pipe to the tip surface of the receiving port of the preceding pipe via the first and second cushion portions for transmitting the propulsive force of the cushion body.

Further, outside the bend of the curved portion,
Although the distance between the flange and the tip surface of the receiving port is enlarged, the cushion portion of the first or second cushion for preventing the inflow of earth and sand of the cushion body is sufficiently extended accordingly. The state in which the front end surface of the flange and the front end surface of the receiving opening are in close contact with each other can be surely maintained, and therefore inflow of earth and sand can be prevented.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The same components as those of the above-mentioned conventional example are designated by the same reference numerals and the description thereof will be omitted.

A cushion body 31 formed in an annular shape is externally fitted to the insertion port 4 of the succeeding pipe 3 to form a flange 5 of the succeeding pipe 3.
And the tip surface of the receptacle 2 of the leading tube 1 are attached. The outer diameter of the cushion body 31 is the same as the outer diameter of the flange 5 and the socket 2, and the front and back surfaces of the cushion body 31 are formed flat so that the tip surface of the flange 5 and the tip of the socket 2 are formed. Contact almost the entire surface.

The cushion body 31 has first and second cushion portions 32 and 33 for transmitting a propulsive force, and first and second cushion portions 34 and 35 for preventing the inflow of earth and sand. The cushion portions 32, 33 for transmitting the propulsive force and the cushion portions 34, 35 for preventing the inflow of earth and sand are alternately arranged in the circumferential direction, and the cushion portions 32, 33, 34, 35 are respectively cushion bodies 31. It is formed in a fan shape that occupies a quarter of the area.

Further, the first and second for transmitting the propulsive force.
Cushion portions 32 and 33 are formed of a resin material such as styrene resin having a hardness necessary for transmitting the propulsive force, and the first and second cushion portions 34 and 35 for preventing the inflow of the sediment are sponge-like foam. It is made of a stretchable elastic material such as polyethylene resin.

The operation of the above structure will be described below.
The first cushion part 34 for preventing the inflow of earth and sand is directed toward the inner side of the bend of the curved portion 11 of the buried pipeline 9, and the second cushion part 35 for the inflow of earth and sand is directed toward the outer side of the bend, The cushion body 31 is fitted onto the insertion opening 4 and attached between the flange 5 and the tip surface of the receiving opening 2. This allows the curved section
Inside the bend of 11, the distance between the flange 5 and the tip surface of the receiving port 2 is reduced, but in response to this, the first cushion portion 34 for preventing inflow of sediment is sufficiently compressed in the pipe length direction. Therefore, even when the pipes 1 and 3 have a large diameter or the curved portion 11 has a large bending angle, the compressive stress generated between the flange 5 and the tip surface of the receiving port 2 inside the curved portion 11 is small. Dispersed in a wide range, the allowable resistance is improved. At this time, the propulsive force is applied from the flange 5 of the rear pipe 3 to the cushion body.
First and second cushion parts 32 for transmitting propulsive force of 31;
It is reliably transmitted to the tip surface of the receiving port 2 of the leading tube 1 via 33.

Further, on the outer side of the bend of the curved portion 11, the distance between the flange 5 and the tip surface of the receiving port 2 is enlarged, and accordingly, the second cushion portion for preventing the inflow of earth and sand of the cushion body 31. Since 35 extends sufficiently in the pipe length direction,
The second cushion portion 35 can surely maintain the state in which the front end surface of the flange 5 and the front end surface of the receiving port 2 are in close contact with each other, so that the inflow of earth and sand can be prevented.

As described above, the cushion body 31 fitted onto the insertion opening 4 is provided with the first and second cushion portions 32 and 33 for transmitting the propulsive force and the first and second cushion portions 34 for preventing the inflow of earth and sand. , 35, and the cushion parts 32, 33 for transmitting the propulsive force are made of a hard material, and the cushion parts 34, 35 for preventing the inflow of sediment are made of a flexible material, so that the propulsion from the succeeding pipe 3 is promoted. The force can be reliably transmitted to the preceding pipe 1 through both the cushion portions 32 and 33, and the compressive stress acting on the joint portion between the succeeding pipe 3 and the preceding pipe 1 can be dispersed through the cushion portion 34. Further, the inflow of earth and sand from the joint portion can be prevented via the cushion portion 35.

Further, the cushion body 31 is cheaper and easier to install than the conventional earth and sand inflow prevention plate 16 (see FIG. 8). Further, the outer diameter dimension of the flange 5 and the rib 6 may be the same as the outer diameter dimension of the receiving port 2, and the outer diameter dimension of the flange 5 and the rib 6 is changed to be smaller than the outer diameter dimension of the receiving port 2 as in the conventional case. It becomes unnecessary to do.

In the above embodiment, the first cushion portion 34 for preventing the inflow of sediment is directed toward the inside of the bend of the curved portion 11 of the buried pipeline 9, and the second cushion portion 35 for preventing the inflow of sediment is curved. Although it is directed to the outside of the bend of the part 11,
The first cushion portion 34 for preventing the inflow of sediment is directed toward the outside of the bend of the curved portion 11 and the second cushion portion 34 for preventing the inflow of sediment is provided.
The cushion portion 35 may be directed toward the inner side of the bend of the curved portion 11 to disperse the compressive stress through the cushion portion 35 and prevent the inflow of earth and sand through the cushion portion 34.

[0024]

As described above, according to the present invention, the first and second cushion portions for preventing the inflow of earth and sand are directed toward the inside and the outside of the bend of the curved portion of the buried pipe line. By externally fitting into the insertion opening, the distance between the flange and the tip surface of the receiving opening is reduced on the inside of the bend,
In response to this, either the first or the second cushion portion for preventing the inflow of earth and sand of the cushion body is sufficiently compressed, so that when the pipe diameter is large or the curved portion has a large bending angle. Also, the compressive stress generated on the flange inside the bend and the tip surface of the receiving port is widely dispersed,
Allowable resistance is improved. At this time, the propulsive force is reliably transmitted from the flange of the subsequent pipe to the tip surface of the receiving port of the preceding pipe via the first and second cushion portions for transmitting the propulsive force of the cushion body.

Furthermore, outside the bend of the curved portion,
Although the distance between the flange and the tip surface of the receiving port is enlarged, the cushion portion of the first or second cushion for preventing the inflow of earth and sand of the cushion body is sufficiently extended accordingly. The state in which the front end surface of the flange and the front end surface of the receiving opening are in close contact with each other can be surely maintained, and therefore inflow of earth and sand can be prevented.

As described above, the cushion body is constructed by being divided into the first and second cushion portions for transmitting the propulsive force and the first and second cushion portions for preventing the inflow of the sediment, and both the cushion portions for transmitting the propulsive force. By applying different materials to the cushion part and both cushion parts for preventing the inflow of sediment, it is possible to reliably transmit the propulsive force from the subsequent pipe to the preceding pipe through both the cushion parts for transmitting the propulsive force, and The compressive stress acting on the joint between the succeeding pipe and the preceding pipe can be dispersed through one of the cushions for preventing sediment inflow, and the inflow of sediment from the joint can be prevented by the other cushion for preventing sediment inflow. Can be prevented through the part. Further, the cushion body is cheaper and easier to install than the earth and sand inflow prevention plate of the conventional example, and the outer diameter dimension of the flange and the rib may be the same as the outer diameter dimension of the receiving port. It becomes unnecessary to change the outer diameter dimension of the flange and the rib to be smaller than the outer diameter dimension of the receiving port.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a cushion body attached to a joint portion between a leading pipe and a trailing pipe for a propulsion method in an embodiment of the present invention.

FIG. 2 is a view on arrow AA in FIG.

FIG. 3 is a side view of a cushion body.

FIG. 4 is a cross-sectional view of a joint portion between a leading pipe and a trailing pipe in a conventional example.

FIG. 5 is a schematic view of a buried pipeline having a curved portion in the middle in a conventional example.

FIG. 6 is a cross-sectional view of a conventional cushion body mounted on a joint portion between a leading pipe and a trailing pipe.

FIG. 7 is a view taken along the line BB in FIG.

FIG. 8 is a cross-sectional view of a conventional earth and sand inflow prevention plate mounted on a joint portion between a leading pipe and a trailing pipe.

[Explanation of symbols]

 1 Preceding pipe 2 Receiving port 3 Subsequent pipe 4 Inserting port 5 Flange 31 Cushion body 32 First cushion part for transmitting propulsive force 33 Second cushion part for transmitting propulsive force 34 First cushion part for preventing sediment inflow 35 Second cushion part for preventing sediment inflow

Claims (1)

[Claims] 1. A tip end surface of a receptacle of a leading pipe for a propulsion method,
It is attached to the outer periphery of the insertion opening of the succeeding pipe and is externally fitted to the insertion opening portion between the flange and the tip end surface of the reception opening that transmits the propulsive force when the insertion opening is inserted into the reception opening. A first and second cushion portion for transmitting a propulsive force and first and second cushion portions for preventing the inflow of earth and sand.
And the cushion portions for transmitting the propulsive force and the cushion portions for preventing the inflow of earth and sand are alternately arranged in the circumferential direction, and the first and second cushion portions for transmitting the propulsive force are provided. Is formed of a resin material having a hardness required to transmit a propulsive force, and the first and second cushion portions for preventing the inflow of earth and sand are formed of a stretchable elastic material. body.