JPS5841399B2 - How to join the middle press part of propulsion steel pipe - Google Patents

Description

Detailed Description of the Invention The present invention is a propulsion method for laying pipes such as water supply pipes underground by propelling the steel pipes into the ground without excavating the road surface or ground surface. Concerning a method for joining steel pipes underground.

For example, when laying various types of steel pipes underground, such as when laying water steel pipes under a road, instead of using the so-called open-cut method, which involves excavating the road surface or ground surface and burying the steel pipes underground, the road surface or ground surface is excavated. A so-called propulsion method was developed to bury steel pipes underground without having to do so.

In this method, steel pipes are propelled into the ground by a hydraulic jack installed in one of two pits that are opened a predetermined distance, and the steel pipes are pushed into the ground by the hydraulic jack from one of the pits. This is a method of laying steel pipes between the pits and the other pit by propelling the steel pipes underground.

When laying water steel pipes under roads using such a propulsion method, it is necessary to increase the distance between both pits, that is, the propulsion distance, due to worsening traffic conditions in recent years.

However, to propel the steel pipe over a long distance using the main thrust jack installed in one pit, not only does it require a main thrust jack with a huge thrust, but also it is difficult to apply a large thrust to the steel pipe by the main push jack. Since this is not possible due to the strength of The propulsion steel pipe 2 on the front side as an end is advanced by an intermediate jack 4,
Next, the rear propulsion steel pipe 3 is pushed forward by the main push jack 6 in one of the pits 5, and by alternately driving the main push jack 6 and the intermediate jack 4, a kind of oscillating motion is applied to the propulsion steel pipe. A construction method has been developed in which the propulsion steel pipe can be laid even over a long propulsion distance by propelling the steel pipe to the other pit 7 without increasing the thrust of the main pusher jack 6.

For short-distance propulsion where it is not necessary to install intermediate jacks, all propulsion steel pipes are propelled after welding adjacent propulsion steel pipes, and for long-distance propulsion where intermediate jacks are installed at the intermediate thrust part. In propulsion, the adjacent propulsion steel pipes are welded together except for the middle pushing part, so there is no possibility of leakage of earth, sand or water in these parts. When laying, there is a ground 1 between the propulsion steel pipes 2 and 3 on the front side and the rear side of the intermediate push part where the intermediate jack 4 is installed.
When installing steel propulsion pipes at a location lower than the level of soil and water inside, especially groundwater, there is a risk that groundwater may leak, and if there is even a slight leakage of water, it may be difficult to weld the steel propulsion pipes together. Therefore, in this long-distance propulsion method using intermediate jacks, it is necessary to prevent water leakage at intermediate jacks, especially during welding. This was one of the important issues to be solved.

The above-mentioned conventional propulsion steel pipe joining method is shown in FIG. The outer tube part 14 formed by the mortar 12 and 13
．． 15 to the front and rear propulsion steel pipes 2
, 3 are formed, and the inner steel tubes 8 and 9 are formed to protrude in the axial direction from the outer tube portions 14 and 15, respectively, as shown in FIG.

In order to prevent the leakage of earth and water from the outside when both the front and rear propulsion steel pipes 2 and 3 are propelled alternately and when these propulsion steel pipes 2 and 3 are welded, the front side A sleeve 16 welded to the outer steel pipe 10 of the propulsion steel pipe 2 of
and the outer circumferential surface of the propulsion steel pipe 3 on the rear side by a 01J ring 18 housed in an annular support fitting 17 fixed to the propulsion steel pipe 3 on the rear side. A water-stop rubber gasket 2 is attached to the formed tapered surface 19.
By pushing in the O-ring and bringing it into pressure contact with the inner circumferential surface of the sleeve 16, water leaking from the O-ring 18 is sealed.

In order to seal with the water stop rubber gasket 20, it is necessary to press it, and therefore an intermediate jack (not shown) installed between the inner steel pipes 8 and 9 of both propulsion steel tubes 2 and 3 and the water stop rubber gasket 20 are used. A short turnbuckle (not shown), such as a fallen tree, is installed between the water stopper rubber gasket 20 when the intermediate jack is used to alternately propel both the front and rear propulsion steel pipes. Trying to keep it sealed.

After the alternate propulsion is finished, the intermediate jack and the short turnbuckle are removed, and then the long turnbuckle 22 is inserted through the pushing ring 21 as shown in FIG.
This presses the water-stopping rubber gasket 20 to prevent leakage of water or earth and sand.

Then, the iron segment 23 having an arc-shaped cross section is inserted into the inner tube portion 8,
By inserting the segment 23 between the segments 9 and welding the segment 23 and the inner tube portions 8 and 9, the inner steel tubes 8 and 9 on the front side and the rear side are joined to each other via the segment 23.

In such conventional joining methods, the installation of the turnbuckle 22 for pressing the water-stopping rubber backing 20 not only requires complicated work such as reassembling and inserting multiple segments 23, but also involves many complicated operations such as reassembling and inserting multiple segments 23. Since the amount of welding between the plurality of segments 23 and the inner steel pipes 8 and 9 for welding the inner steel pipes 8 and 9 was enormous, welding distortion had a large negative effect on the propulsion steel pipe.

The present invention improves the conventional joining method as described above, and aims to provide a joining method that enables inner steel pipes to be welded together while preventing water leakage. Of the two propulsion steel tubes that protrude in the axial direction from the pipe section and are concentrically adjacent to each other, it is fixed to the front propulsion steel tube and can slide freely against the outer circumferential surface of the rear propulsion steel tube. A primary water-stopping 01J ring is interposed between the sleeve that fits into the sleeve and the rear propulsion steel pipe to prevent dirt and water during alternate forward movement of the front and rear propulsion steel pipes. A secondary water stopper 01 is provided between the sleeve and a tapered portion formed in the rear propulsion steel pipe so that the diameter becomes gradually smaller toward the tip.
After inserting the J-ring, the rear propulsion steel pipe is moved forward toward the front propulsion steel pipe, and the forward movement of the rear propulsion steel pipe causes the two parts to separate between the tapered portion and the sleeve. The inner steel pipes of both propulsion steel pipes are welded together while the secondary water stop O-ring is crushed in the radial direction and the water leaking from the 01J ring is sealed with the secondary water stop O-ring. This is a method for joining the intermediate pressed portion of a propulsion steel pipe, which is characterized by the following.

Next, an explanation will be given based on an embodiment of the present invention shown in Figs. 3 to 7. Figs. 3 to 6 show adjacent front propulsion steel pipes 3.
0 and a part of the propulsion steel pipe 31 on the rear side,
Each propulsion steel pipe 30°31 is an inner steel pipe 32.33
and outer steel pipe 34°35 and this and inner steel pipe 32.33
The inner steel pipes 32, 33 are formed to protrude in the axial direction from the outer pipe parts 38, 39.

When the front propulsion steel pipe 30 and the rear propulsion steel pipe 31 move forward alternately, the sleeve 40 that slides and fits on the outer peripheral surface of the rear propulsion steel pipe 31 is attached to the front propulsion steel pipe 30.
Two primary water-stopping O-rings 41 and 42 are interposed between the sleeve 40 and the rear propulsion steel pipe 31 to prevent earth and water from leaking into the respective propulsion steel pipes 30 and 31. This prevents entry.

Of the two primary water-stopping 01J-rings 41, 42, one of the primary water-stopping 01J-rings 41 is housed in a groove 43 formed in the outer steel pipe 35, as shown in FIG. The water-stopping 0'J song 2 is also housed in a groove 44 formed in the outer steel pipe 35, as shown in FIG. 3C.

In order to move the forward propulsion steel pipe 30 and the rear propulsion steel pipe 31 forward alternately, an intermediate jack 47 is installed between both propulsion steel pipes 30 and 31 via fittings 45 and 46, By driving the intermediate jack 47 once, the front propulsion steel pipe 30 is advanced with the rear propulsion steel pipe 31 as a fixed support end.

After advancing the front propulsion steel pipe 30 by a predetermined distance, the driving of the intermediate jack 47 is stopped, and the rear propulsion steel pipe 31 is advanced by the main push jack 6 in the pit, and the front propulsion steel pipe 30 is moved forward. Get closer.

This is repeated to cause the propulsion steel pipe to perform a kind of oscillating motion, thereby propelling the propulsion steel pipe 30, 31 underground.

During this propulsion movement, there are two primary water stoppages.
．． 42 maintains a primary water stop and seals out the inflow or leakage of earth and sand and water from the outside.

A tapered part 48 is formed at the distal end of the rear propulsion steel pipe 30 so that the diameter becomes gradually smaller toward the distal end, and the front propulsion steel pipe 30 and the rear propulsion steel pipe 3 are connected to each other.
After moving forward alternately with 1, both front and rear propulsion steel pipes 3
0.31, remove the intermediate jack and insert the secondary water-stopping 01J ring 49 between the sleeve 40 and the tapered part 48 of the propulsion steel pipe 31 on the rear side, as shown in FIG. .

Then, the propulsion steel pipe 3 on the rear side is
1 is advanced toward the forward propulsion steel pipe 30, the secondary water-stopping 01J ring 49 is crushed in the radial direction between the sleeve 40 and the tapered part 48 due to the wedge effect of the tapered part 48, and the sleeve 40 and the outer periphery of the propulsion steel pipe on the rear side.

The forward movement of the rear propulsion steel pipe 31 crushes the secondary water stop 01J ring 49, and at the same time, both propulsion steel pipes 3
0.31 inner steel pipe 32.33 butt against each other.

Therefore, even if the water leaking through the blow-off water stop 01J rings 41 and 42 is small, the secondary water stop 01J
Both propulsion steel tubes 30.
31 tube ends 53 can be welded.

After the welding is finished, the sleeve 40 and the inner steel pipe 30.31
Mortar 50 is injected between.

This state is shown in Figure 5.7.

When matching the inner steel pipes 32 and 33 of the front and rear propulsion steel pipes 30 and 31, the inner steel pipe 32
The axis of the inner steel pipe 33 may be misaligned with the axis of the inner steel pipe 33.

In order to correct this, a secondary water stop O
After inserting the ring 49, stoppers 51 are welded to the outer peripheral surface of the inner steel pipe 32 of the forward propulsion steel pipe 30 all around or at predetermined intervals, and the guide 52 is fitted annularly to the outer peripheral surface of the inner steel pipe 32. You can also do it.

In this way, in the joining method of the present invention, since the inner steel pipes 32 and 33 can be welded by directly butting each other, the amount of welding is smaller than in the conventional method, and the welding distortion is reduced, but the same as in the conventional method. Of course, it is also possible to interpose a segment between the inner steel pipes 32 and 33 and weld the inner steel pipes together via the segment.

In the conventional method shown in Fig. 2, the 01J ring and the water-stopping rubber packing 20 are always sealed not only during welding but also during propulsion, but in the present invention, the primary water-stopping rubber seal 20 is used during propulsion. 0 'Try to temporarily stop the water with a J song,
Even if there is a small amount of water leaking at this time, it will not cause difficulty in the propulsion work, but if water leaks during welding, it may cause welding defects, so in this case, use the secondary water stop. Seal with an O-ring.

Therefore, according to the present invention, even if the primary water-stopping 01J ring is damaged by earth and sand during propulsion movement of the propulsion steel pipe, and even a small amount of groundwater leaks into the propulsion steel pipe, the secondary water-stopping 01J ring Since the space between the sleeve and the propulsion steel pipe is completely sealed during welding, welding can be carried out under good conditions without the influence of moisture, and the space between the front and rear propulsion steel pipes is completely sealed. Conventionally, welding was performed by inserting multiple segments, but with the present invention, it is now possible to weld the ends of both propulsion steel pipes directly against each other, which simply simplifies the welding work. This resulted in an excellent joining method that did not cause any thermal distortion during welding.

[Brief explanation of drawings]

Figure 1 is a sectional view showing the state in which the propulsion method is being carried out, Figure 2 is a sectional view showing the conventional method of joining steel pipes for propulsion, and Figure 3
Figure A is a sectional view showing the joining method of the present invention, and shows a state in which an intermediate jack is installed between both propulsion steel pipes. Figure 3B is an enlarged sectional view of section B in Figure 3A, and Figure 3C is an enlarged sectional view of section B in Figure 3A.
Fig. 4 is a sectional view showing the state in which the secondary water stop 01J ring is installed; Fig. 5 is a sectional view showing the welded state; Fig. 6 is an enlarged sectional view of part C in Fig. A; FIG. 7 is a cross-sectional view showing a specific example of butting, and FIG. 7 is a perspective view showing a state in which the joining is completed. In the drawing, 30 is a forward propulsion steel pipe, 31 is a rear propulsion steel pipe, 32 and 33 are inner steel pipes, 38° and 39 are outer pipe parts, 40 is a sleeve, 4L42 is an O-ring for primary water stop,
47 is the intermediate jack, and 49 is the secondary water stop O-ring.

Claims (1)

[Claims] 1. Of two propulsion steel tubes in which the inner steel tube is formed so as to protrude in the axial direction than the outer tube portion, and which are concentrically adjacent to each other in the front and back, it is fixed to the front propulsion steel tube and attached to the outer circumferential surface of the rear propulsion steel tube. A primary water-stopping 01J ring is interposed between the sleeve slidably fitted to the rear propulsion steel pipe, and the front and rear propulsion steel pipes are alternately moved forward. A secondary water stop is provided between the sleeve and a tapered part formed in the rear propulsion steel pipe so that the diameter gradually becomes smaller toward the tip. After inserting the O-ring, the rear propulsion steel pipe is moved forward toward the front propulsion steel pipe, and the forward movement of the rear propulsion steel pipe causes the two parts to separate between the tapered portion and the sleeve. The 01J ring for secondary water stop is crushed in the radial direction, and the inner steel pipes of both propulsion steel pipes are welded together while sealing the water leaking from the 01J ring for secondary water stop with the 01J ring for secondary water stop. 1. A method for joining a middle press part of a propulsion steel pipe, characterized in that: