JPH1047568A - Earthquake resistant pipe joint for cable laying pipe line - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an earthquake resistant pipe joint for a cable laying pipe line strong against large displacement in the ground horizontal direction due to sideward flow. SOLUTION: In this constitution comprising a leading pipe unit 1 which must be propulsively buried in the ground, following pipe unit 2 and a joint pipe 3 connecting these pipe units 1, 2, in a peripheral surface of the leading/ following pipe unit 1, 2, hollow-shaped notched parts 4, 5 having a prescribed length in the pipe axial direction are provided, in both end inner surface sides of the joint pipe 3, ring use annular grooves 6, 7 fitting water cut-off rings 12, 13 are provided, and in both end outer surface side thereof, bolt holes 10, 11 screwing coming off preventing bolts 8, 9 so as to correspond to the notched parts 4, 5 are respectively provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic pipe joint for a cable laying pipeline.

[0002]

2. Description of the Related Art Conventionally, when laying a power cable or a communication fiber cable under a road surface, various pipe materials such as a steel pipe or a cast iron pipe (including a ductile cast iron pipe), or a polyethylene pipe or a concrete pipe are used. Have been. By the way, when installing these buried pipes, since Japan is an earthquake country, seismic study is required.For example, after confirming the seismic performance of the pipeline in accordance with the seismic design formula based on the response displacement method, Has been done. However, in spite of such seismic design, recent damage to buried pipes during the earthquake shows that many cases of breakage due to breakage or breakage of pipe joints near the liquefied ground have been reported. That is the current situation.

In particular, recent seismic engineering knowledge has revealed that large horizontal displacement of the ground due to lateral flow is one of the main causes of damage to underground structures. According to the results, observations and investigations have reported that the horizontal displacement of the ground due to lateral flow can range from several tens of cm to several meters. Also, conventional pipe joints are mainly welded joints as described in, for example, an example of a coated steel pipe for direct push propulsion in JP-A-63-251692. Since time is required, there is a problem that the manufacturing cost is high in addition to the above-mentioned disadvantages such as breakage at the joint.

Japanese Patent Application Laid-Open No. 48-97114 discloses an example of an earthquake-resistant pipe joint called a push-in steel pipe joint.
The content is such that a pair of annular holding fittings extending in parallel along the inner peripheral surface thereof are fixed to the joint outer pipe attached to the end of one steel pipe to be connected, and formed by the respective annular holding fittings. An outer peripheral ridge of an annular packing is fitted and fixed to the annular groove by an adhesive, and a tapered taper portion is provided on an outer periphery of an end of the other steel pipe inserted into the annular packing in the outer tube of the joint. The annular packing is a part of which is crimped on the outer peripheral surface of the steel pipe in a state of covering the inner peripheral surface of the annular holding fitting on the proximal end side of the outer pipe of the joint. There is a problem that the cost is high due to the structure of joining the outer tubes by welding.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and is directed to a steel pipe for insertion, a waterproof ring made of rubber, and a joint portion for transmitting thrust. The pipe has a joint structure consisting of a wear-resistant material used for its outer coating and is buried against large ground displacement such as lateral flow caused by ground liquefaction during an earthquake. It is an object of the present invention to provide an earthquake-resistant pipe joint for a cable laying pipeline capable of safely protecting an internal cable without damaging a pipe.

[0006]

According to the present invention, there is provided a seismic pipe joint for a cable laying pipe which is to be buried in advance in a soil.
(1) and trailing pipe (2) and connecting pipe (3) connecting them
A concave notch (4) having a predetermined length in the pipe axis direction is provided on the outer peripheral surfaces of the leading pipe (1) and the trailing pipe (2).
, (5), and ring-shaped annular grooves (6), into which water-stop rings (12), (13) are fitted on the inner surfaces of both ends of the joint pipe (3).
(7) and the notches (4) and (5)
It is characterized in that bolt holes (10) and (11) for screwing the retaining bolts (8) and (9) are provided so as to face each other.

Further, according to the present invention, a pin (1) is provided on the outer peripheral surfaces of the leading pipe (1) and the trailing pipe (2) at predetermined positions from the pipe ends.
4) and (15) are implanted, and a ring-shaped annular groove (6) in which water-stop rings (12) and (13) are fitted into the joint pipe (3) on the inner surface sides at both ends.
, (7) and the pins (14), (15)
Characterized in that lightning-like cuts (16) and (17) each having a predetermined length in the pipe axis direction and opening at the pipe end are provided so as to face the pipes.

The inner surface of the joint pipe (3) is preferably tapered so that the wall thickness gradually decreases from the center to both ends.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention. In this figure, 1 is a preceding pipe such as a steel pipe to be buried in the soil, and 2 is a trailing pipe such as a steel pipe to be buried in the soil similarly to the preceding pipe 1. Reference numeral 3 denotes a tubular joint pipe for connecting the leading pipe 1 and the trailing pipe 2, and its outer surface is coated with a wear-resistant material such as a resin.

[0010] On the outer peripheral surfaces of the ends of the leading tube 1 and the trailing tube 2, concave notches 4, 5 having a length L in the tube axis direction are provided at predetermined positions from the ends. (See FIG. 2). In addition,
It is preferable that the number of the cutout portions 4 and 5 is, for example, four in total in the upper, lower, left, and right directions, but may be increased or decreased according to the diameter of the pipe or the burial location. Ring grooves 6 and 7 are provided on the inner surfaces of both ends of the joint pipe 3, and retaining bolts 8 and 9 are screwed on the outer surfaces of the joint tubes 3 at positions facing the notches 4 and 5. The corresponding bolt holes 10 and 11 are provided.

Therefore, the annular grooves 6, 7 for the ring of the joint pipe 3 are provided.
After inserting rubber waterproof rings 12 and 13 into the inside of the tube, the rear end of the leading tube 1 and the leading end of the trailing tube 2 are inserted into the inner surface thereof so that both ends thereof come into contact with each other. , 11
The retaining bolts 8 and 9 are screwed together, and the tips of the bolts are engaged with the notches 4 and 5. In this way, by fixing the joint pipe 3 to both pipes, the connection between the leading pipe 1 and the trailing pipe 2 is completed.

By configuring the pipe in this way, even if an earthquake occurs, the joint pipe 3 is connected to the leading pipe 1 and the trailing pipe 1 until the displacement of the ground in the pipe axis direction reaches the maximum L. There is no escape from the tube 2. In addition, waterproof ring 12,
Because the joint part bends due to the elastic deformation of 13,
Even if a displacement in a direction perpendicular to the tube axis is applied by the lateral flow, the displacement can be absorbed by the axial displacement, rotation, or deformation of the tube cross section.

Although the inner surface of the joint pipe 3 in FIG. 1 has a straight shape in the pipe axis direction, as shown in FIG. 3, the taper is such that the wall thickness gradually decreases from the center to both ends. If the joint pipe 3A having the shape is used, the bending angle of the joint portion can be increased, so that it is possible to cope with propulsion construction under complicated terrain conditions. FIG. 4 shows another embodiment of the present invention. That is, the leading pipe 1
And notches 4, 5 at predetermined positions from the end of the trailing pipe 2
Instead, pins 14 and 15 are implanted, while notches 16 and 17 are formed in the joint pipe 3B instead of the bolt holes 10 and 11. FIG. 5 shows a plan view of one of the notches 17 in the cut portion. First, a first cut portion 17a is formed along the pipe axis from the end to the center, and then, in the circumferential direction. On the other hand, a second cut portion 17b obliquely directed toward the end portion is formed, and a third cut portion 17c having a length L along the pipe axis is formed again toward the center portion, so-called lightning. A groove is provided. It is preferable that a plurality of pins 14 and 15 are provided on the outer peripheral surface in the same manner as the notches 4 and 5.

When, for example, the trailing pipe 2 is connected to the joint pipe 3 thus configured, the first notch 17a of the joint pipe 3 is aligned with the pin 15 of the trailing pipe 2. The trailing tube 2 is pushed in, pulled back while rotating in the circumferential direction along the second notch 17b, and then pushed again in the axial direction of the tube along the third notch 17c. The preceding tube 1 can be connected in the same procedure.

Although the inner surface of the joint pipe 3 in the pipe axis direction in FIG. 4 is straight, the joint pipe 3C having a tapered shape as shown in FIG. Can be handled.

[0016]

As described above, according to the present invention,
Since the plug-in type joint pipe is used, the following effects can be obtained. Since the joining can be performed easily and in a short time, the cost can be greatly reduced. By appropriately setting the length of the notch or notch in the pipe axis direction, it can follow the displacement of the ground. Curved movement is also possible by elastic deformation of the water stop ring and tapering of the pipe end, so that it can be applied to propulsion construction under complicated terrain conditions.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of the present invention.

FIG. 2 is a partial plan view showing a cutout portion of a tubular body.

FIG. 3 is a partial side sectional view showing another embodiment of the joint pipe.

FIG. 4 is a partial side sectional view showing another embodiment of the present invention.

FIG. 5 is a partial plan view showing a cut portion of the tubular body.

FIG. 6 is a partial sectional side view showing another embodiment of the joint pipe.

[Explanation of symbols]

 1 Leading pipe 2 Trailing pipe 3, 3A, 3B, 3C Joint pipe 4, 5 Notch 6, 7 Ring groove 8, 9 Retaining bolt 10, 11 Bolt hole 12, 13 Water stop ring 14, 15 pin 16, 17 notch 17a first notch 17b second notch 17c third notch

Claims (3)

[Claims] The present invention comprises a leading pipe (1) and a trailing pipe (2) to be buried underground in the soil, and a joint pipe (3) for connecting the leading pipe (1) and the trailing pipe (2). Concave notches (4) and (5) having a predetermined length in the pipe axis direction are provided on the outer peripheral surface of the pipe (2). ring
Ring annular grooves (6) and (7) into which (12) and (13) are fitted, and retaining bolts (8) are formed on the outer surfaces of both ends so as to face the notches (4) and (5). ), (9) bolt holes (1
An earthquake-resistant pipe joint for a cable laying pipe, characterized by comprising (0) and (11). 2. Pins (14) and (15) are implanted at predetermined positions from the pipe ends on the outer peripheral surfaces of the leading pipe (1) and the trailing pipe (2). 3) Waterproof rings (1
Ring annular grooves (6) and (7) into which 2) and (13) are fitted, and a predetermined length in the pipe axis direction on the outer surface of both ends so as to face the pins (14) and (15). 2. A seismic pipe joint for a cable laying pipe according to claim 1, wherein lightning-like cuts (16) and (17) each having an opening at a pipe end are provided. 3. The joint pipe (3) according to claim 1, wherein an inner surface of the joint pipe (3) is tapered so that a thickness thereof gradually decreases from a central portion toward both ends. Seismic pipe joint for the cable laying pipeline described.