JP2002276285A - Jacking pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost jacking pipe having great water cut-off ability suitable for an ultra-deep jacking method. SOLUTION: On the outer circumferential face of an insert 3 of a jacking pipe main body 1, seal grooves 6 and 7 are formed at a longitudinal interval, and a rubber ring 11 is installed in the front side seal groove 6 while an O-ring 12 is installed in the rear side seal groove 7. The O-ring 12 is provided with longitudinal movement allowance, and the O-ring 12 is pressed to the front wall of the seal groove 7 for increasing the water cut-off ability when a water pressure is applied to it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propulsion pipe used for a propulsion method, and more particularly to a propulsion pipe having excellent water pressure resistance.

[0002]

2. Description of the Related Art When pipes are buried underground, a propulsion method is generally used. However, in order to avoid buried objects such as water and sewage, gas pipes, power and communication cables, etc.
It may be necessary to implement the propulsion method at a large depth. In some cases, it is required to carry out the propulsion method on the shortest route without bypassing the bottom of the sea or lake. In any case, the joint portion of the propulsion pipe is required to have high water stoppage in preparation for intrusion of high water pressure groundwater.

On the other hand, the maximum water stop pressure at the joint portion of a standardized propulsion pipe, which is currently frequently used, is 0.2 MPa. The external water pressure acting on the propulsion pipe during construction is usually from 0.02 to 0.03 MPa for groundwater pressure, lubrication, muddy water pressure, etc., so it depends on the height of the groundwater, but from the ground to the bottom of the pipe About 20m was the limit of adoption. Therefore, it was insufficient to apply to the propulsion method at a large depth as described above.

[0004] Under such circumstances, for the safety of the operator of the drilling machine, the development of a propulsion pipe having a high water stopping property suitable for a large depth or crossing the bottom of a sea or lake has been expected.

As a conventionally known seal structure for a propulsion pipe, there is one as shown in FIG. This propulsion pipe has an inlet 23 reinforced by a steel plate 22 at the tip of a concrete propulsion pipe main body 21, and a steel plate collar 24 attached to the outer peripheral surface of the propulsion pipe main body 21 protrudes to the rear to receive the propulsion pipe. 25 are provided. Seal grooves 26, 27 are formed at two locations on the outer periphery of the outlet 23 at an interval in the front-rear direction, and rubber rings 28, 29 each having a deformed cross-section as a seal member are attached to each of the seal grooves 26, 27. Is done. These rubber rings 28 and 29 are brought into close contact with the inner peripheral surface of the receiving port 25 of another similar propulsion pipe, and the insertion port 23 is inserted to form a joint between the propulsion pipes. Each of the rubber rings 28 and 29 is tightly embedded in the seal grooves 26 and 27 without any gap in the front-rear direction.

The ridge 3 between the seal grooves 26 and 27
1 is provided with a water blocking agent injection hole 32.

[0007]

It has been confirmed that the water stopping power of a conventional propulsion pipe having the above-mentioned sealing structure is 0.2 MPa or more. Whether or not was not confirmed.
As will be described later, according to experiments conducted by the present inventors, it has been found that they have a considerably high water stopping power, and that they are not necessarily unsuitable for the deep-depth propulsion method.

However, the above-mentioned sealing structure is a structure in which rubber rings 28 and 29 are attached to two sealing grooves 26 and 27, respectively, and each of the rubber rings 28 and 29 has a special sectional structure. Therefore, there is a problem that the cost is higher than a seal structure using a standard product such as an O-ring.

On the other hand, in terms of cost, the rubber rings 28, 2
Although it is considered to be advantageous to use an O-ring in place of 9, each of the seal grooves 26 and 27 is also formed in a shape conforming to the O-ring, and a normal mounting method is employed in which the O-ring is densely embedded therein. It is clear from experience based on the previous experience that when this method is used, there is a cost reduction effect, but the water stopping power is insufficient.

Accordingly, an object of the present invention is to provide a propulsion pipe having a sealing structure which has a water stopping power applicable to a large depth propulsion method and can be reduced in cost.

[0011]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a concrete propulsion pipe main body having an inlet reinforced by a steel plate at a tip end thereof, and an outer peripheral surface of the propulsion pipe main body. A receiving port is provided by projecting the attached steel plate collar to the rear, and a sealing member is attached to a sealing groove formed at an interval in the front-rear direction on the outer periphery of the insertion port, and each sealing member is propelled by another similar propulsion. In the propulsion pipe in which the inlet is inserted by closely adhering to the inner peripheral surface of the receiving port of the pipe, the rearmost one of the seal members is replaced by O.
The O-ring is formed by a ring, and the seal groove of the O-ring is formed to have a width that allows the O-ring to move in the front-rear direction. The rear side of the O-ring is configured to be opened to the outside through a gap between the insertion port and the reception port while the insertion port is inserted into the reception port of another propulsion pipe.

In the propulsion pipe having the above configuration, during the propulsion, the propulsion is continued while inserting the above-mentioned insertion port into the reception port of another preceding similar propulsion pipe to form a joint part sequentially. In the part where the groundwater flows out, the groundwater having the required water pressure enters through the gap between the inlet and the receptacle and acts on the O-ring. The O-ring is pressed by the water pressure and is pressed against the front end wall of the seal groove to exert a large water stopping power.

The O-ring may have a configuration in which a taper is applied to the front end wall of the seal groove of the O-ring.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, the propulsion pipe according to the embodiment has an insertion port 3 reinforced by a steel plate 2 at the tip of a concrete propulsion pipe main body 1 reinforced by a reinforcing bar, and an outer periphery of the propulsion pipe main body 1. A receiving port 5 is provided by projecting a steel plate collar 4 attached to the surface to the rear. The outlet 3 is formed to have a slightly smaller diameter than the portion where the collar 4 is mounted, so that it can be inserted into the receiving port 5 of another similar propulsion pipe 1 with a margin. The above steel plate 2 and collar 4
Are overlapped on the outer diameter surface of the propulsion pipe body 1 and joined by welding.

A first seal groove 6 and a second seal groove 7 are provided at a predetermined distance from the front end of the outlet 3.
A certain interval is provided between the seal grooves 6 and 7 by a ridge 8 rising from the bottom thereof. In addition, from the rear of the second seal groove 7 to the rear end of the insertion opening 3, a narrowed portion 10 having the same diameter as each of the seal grooves 6 and 7 is formed. First and second
The seal portions 6 and 7 are formed to have the same width (for example, 26 mm). As shown in FIG. 2, a rubber ring 11 having a deformed cross section similar to the conventional one is densely mounted in the first seal groove 6. The rubber ring 11 has a taper on the outer peripheral surface with a small diameter at the front end portion, and the rear end portion rides on the ridge 8. The portion having the maximum diameter is formed slightly larger than the inner diameter of the receiving port 5.

An O-ring 12 is mounted in the second seal groove 7. The diameter of the O-ring 12 is formed smaller than the width of the second seal groove 7 (for example, 14 mm), and there is a gap between the O-ring 12 and the front and rear wall surfaces of the seal groove 7 so that the O-ring 12 can move in the front-rear direction. The outer diameter of the O-ring 12 is equal to the maximum outer diameter of the rubber ring 11.

A protective plate 13 made of a steel plate is provided on the front end surface of the outlet 3 and is welded to the steel plate 2 on the outer periphery of the outlet 3. A protective plate 13 'welded to the collar 4 is also provided on the inner end face of the receptacle 5 shown in FIG.

The propulsion pipe according to the embodiment is as described above. As shown in FIG. 3, a required pressing force is applied to the outlet 3 of the same propulsion pipe 1 by the propulsion method. Inserted. The rubber ring 11 and the O-ring 12 are pressed against the inner surface of the receiving port 5 in a state where the protective plate 13 of the insertion port 3 is pressed against the protecting plate 13 ′ of the inner end face of the receiving port 5, thereby forming a joint portion in a sealed state. Is done.

When a high external water pressure acts around the joint, the O-ring 12 passes through the gap 14 opened to the outside.
The O-ring 12 moves forward as shown in FIG. 4 and is pushed between the ridge 8 and the inner surface of the receiving port 5, so that a large water stopping power is exerted.

As shown in FIG. 5, the second seal groove 7 of the ridge 8 may be provided with a taper 16 (angle θ, for example, 30 degrees).

[0021]

EXAMPLES In order to confirm the water stopping effect of the seal structure of the embodiment described above, a water pressure resistance test was performed in comparison with the conventional example.

(1) Test tube A: A tube of the embodiment shown in FIGS. 1 to 4 (rubber ring + O
Ring: φ14)) B: As shown in FIG. 5 (rubber ring + O-ring φ13, θ3)
0 °)) C: Conventional example shown in FIG. 6 (rubber ring + rubber ring) In each of the above, φ1000 × 2430 mm, steel synthetic tube specification, seal grooves 6 and 7 width 26 mm, no injection of water stopping agent.

(2) Test method Horizontal water tightness test As shown in FIG. 7, the test tubes were joined horizontally, a water sealing device 17 was attached to the outside of the joint portion, a water pressure of 0.5 MPa was applied, and the pressure was applied for 3 minutes. And check for water leakage. If no abnormality is found, further increase the water pressure to O.D. The test is performed by raising the pressure by 1 MPa to the maximum water stopping power. Sliding horizontal water tightness test Using the same device as in Fig. 7, a sliding width of 5
Water sealing is performed after 16 strokes of 0 mm, and the water pressure is increased in the same manner as described above. After the sliding horizontal water tightness test of the sliding bending water tightness test is completed, the difference between the maximum joint width and the minimum joint width of the joint portion is defined as an opening difference, and the joint is bent so as to have an opening difference of 40 mm. And seal the water
Similarly, increase the water pressure.

(3) Test results

[Table 1]

(4) Discussion In each of the test tubes A and B, a high water stopping power was obtained in any of the tests, and no substantial difference was observed in the earthquake resistance. Test tube C had water leakage in the sliding bending test, but no difference was observed in A and B in other tests.

[0026]

As described above, according to the present invention, the seal structure using the combination of the rubber ring and the O-ring can provide good results in any of horizontal watertight, sliding horizontal watertight, and sliding bending watertight tests. Obtained. As a result, it is possible to realize a propulsion pipe having a large water stopping power and sufficient seismic resistance required for propulsion at a large depth and for propulsion across the seabed and lake bottom. Also, O
Since a ring can be used, cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a bonded state according to an embodiment.

FIG. 2 is a partially enlarged cross-sectional view of the same non-joined state.

FIG. 3 is a partially enlarged cross-sectional view of a bonding state according to the first embodiment;

FIG. 4 is a partially enlarged sectional view of the same pressurized state.

FIG. 5 is a partially enlarged sectional view of a modification of the above embodiment.

FIG. 6 is a cross-sectional view of a conventional example in a non-joined state.

FIG. 7 is a sectional view showing a part of the test apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Propulsion pipe main body 2 Steel plate 3 Insert 4 Collar 5 Receptacle 6 First seal groove 7 Second seal groove 8 Ridge 10 Restricted portion 11 Rubber ring 12 O-ring 13 Protection plate 14 Gap 16 Taper 17 Water sealing device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Osamu Nobe 961 Toendo, Arikawa-cho, Aichi-gun, Shiga Prefecture Inside Kurimoto Concrete Industry Co., Ltd. (72) Inventor Takashi Nakajima 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Inside Nippon Kokan Co., Ltd. (72) Inventor Keisaburo Tokura 1-2-1, Marunouchi, Chiyoda-ku, Tokyo F-term (in reference) 2D054 AC18 AD28 AD29 3H014 AA09 3H015 BA03 BB03 BC02

Claims (3)

[Claims] The present invention provides a concrete propulsion pipe main body having an inlet reinforced by a steel plate at a distal end thereof, and a steel plate collar mounted on an outer peripheral surface of the propulsion pipe main body protruding to a rear portion to provide a receiving port. A seal member is attached to a seal groove formed at intervals in the front-rear direction on the outer periphery of the insertion port, and each seal member is brought into close contact with the inner peripheral surface of the receiving port of another similar propulsion pipe so that the insertion port is inserted. In the propulsion pipe, the rearmost seal member of the seal members is formed by an O-ring, and the seal groove of the O-ring is formed to have a width that allows the O-ring to move in the front-rear direction. Propulsion pipe. 2. The O-ring is open to the outside through a gap between the socket and the receptacle, with the receptacle inserted into a receptacle of another propulsion pipe. 2. The propulsion tube according to 1. 3. The propulsion pipe according to claim 1, wherein a taper is applied to a front end wall of the seal groove of the O-ring.