JPS5841398B2 - How to join the middle press part of propulsion steel pipe - Google Patents

Description

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

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 construction method, steel pipes are propelled underground by a hydraulic jack installed in one of two pits opened a predetermined distance apart, and the steel pipes are pushed into the ground by the hydraulic jack sequentially from this one pit. This is a method of laying steel pipes between pits by pushing them 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 push jack installed in one of the pits, not only does it require a main push 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 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 a kind of oscillating motion is applied to the propulsion steel pipe by driving the main push jack 6 and the intermediate jack 4 alternately. Accordingly, a construction method has been developed in which the steel pipe for propulsion can be laid even over a long distance by propelling it to the other pit 7 without increasing the thrust of the 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 conventional method of joining the above-mentioned propulsion steel pipes is shown in Fig. 2, where the inner steel pipe 8°9, the outermost steel pipe 10.11, and the space between this and the inner steel pipe are filled. The outer tube portion 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 O ring 16, water leaking from the O ring 18 is sealed.

In order to achieve a seal with the water stop rubber gasket 20, it is necessary to press it, and therefore both propulsion steel pipes 2, 3
A short turnbuckle (not shown) is inserted between the intermediate jack (not shown) installed between the inner steel pipes 8 and 9 and the water-stop rubber packing 20, and the intermediate jack is The water-stop rubber gasket 20 is used to achieve sealing when both the front and rear propulsion steel pipes are being alternately propelled.

After the alternate propulsion is finished, the intermediate jack and the short turnbuckle are removed, and the water stop rubber gasket 20 is pressed by the long turnbuckle 22 via the press ring 21 as shown in FIG. Prevents leakage of water or soil.

Then, the iron segments 23 having an arcuate cross section are attached to the inner tube portions 8 and 9.
By inserting the segment 23 (l!: inner l1Il pipe parts 8 and 9 between the butt parts 24 and 25), the inner steel pipes 8 and 9 on the front side and the rear side are inserted through the segment 23. We are trying to unite nine comrades.

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 is enormous, the adverse effect on the propulsion steel pipe due to welding distortion is severe.

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 concentrically adjacent propulsion steel pipes that protrude in the axial direction from the pipe section, it is fixed to the front propulsion steel pipe and slides against the outer circumferential surface of the rear propulsion steel pipe. An 01J ring is interposed between the freely fitting sleeve and the rear propulsion steel pipe to prevent the inflow of earth and water during alternate forward movement of the front and rear propulsion steel pipes. When sealing the rear propulsion steel pipe close to the front propulsion steel pipe and welding these inner steel pipes together, the annular steel pipe installed between the inner steel pipe of the rear propulsion steel pipe and the sleeve Pressure fluid into the rubber tube to inflate the rubber tube so that it comes into close contact with the rear propulsion steel tube and sleeve, and seal the water leaking from the 01J ring with the rubber tube. This is a method for joining intermediate pressed portions of propulsion steel pipes, characterized in that both of the propulsion steel pipes are welded together.

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 01J rings 41 and 42 are interposed between the sleeve 40 and the rear propulsion steel pipe 31 to prevent dirt and water from leaking into the respective propulsion steel pipes 30 and 31. ing.

Of the two 01J rings 4L42, j5's 0 ring 4
1 is accommodated in a groove 43 formed in the outer steel pipe 35 as shown in FIG. 3B, and the other O ring 42 is also accommodated in a groove 44 formed in the outer steel pipe 35 as shown in FIG. 3C. is housed in.

In order to alternately move the forward propulsion steel pipe 30 and the rear propulsion steel pipe 31 forward, an intermediate jack 41 is installed between both propulsion steel pipes 30, 31 via fittings 45, 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 forward propulsion steel pipe 30 by a predetermined distance, the drive of the intermediate jack 47 is stopped 1, 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 to

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, the two 01J rings 41.42 seal against the inflow or leakage of earth and sand and water from the outside.

In order to weld the front propulsion steel pipe 30 and the rear propulsion steel pipe 31 after propulsion is completed, after removing the intermediate jack 47, weld the annular hollow tube with the fluid injection pipe 48 as shown in FIG. 49 is inserted between the sleeve 40 and the inner steel pipe 33 of the propulsion steel pipe 31 on the rear side.

Next, by supplying fluid such as water or compressed air into the tube 49 from the fluid injection pipe 48 and expanding the tube 49, the tube 49 is connected to the inner peripheral surface of the sleeve 40 and the outer peripheral surface of the inner steel pipe 33. Bring it into close contact.

As a result, even if a small amount of water leaks through the 01J ring 4L42, the tube 49 seals the leak.

After closing the valve 48a provided in the fluid injection pipe 48 and sealing the fluid in the tube 49, the rear propulsion steel pipe 31 is brought closer to the front propulsion steel pipe 30 by the pusher jack 6, and the inner steel pipe 32 and The inner steel pipes 33 are butted against each other at their end faces.

In this state, the butt end portion 53 is welded.

After the welding operation is completed, mortar 50 is injected between the inner steel pipe 32, 33 and the sleeve 40.

This state is shown in FIGS. 5 and 7.

The rubber tube 49 is closed by pressurizing the fluid into the rubber tube 49.
The inner steel tubes 32.3 of both the front and rear propulsion steel tubes 30.31 inflate the rubber tube 49 so that it comes into close contact with the rear propulsion steel tube 31 and the sleeve 40.
It is operationally convenient to do this when welding the three comrades together, but it is also possible to keep the rubber tube 49 in an expanded state even during propulsion movement earlier than that. Even in this case, the insertion operation of the rubber tube 49 can be performed in advance during the propulsion movement.

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, after inserting the rubber tube 49 as shown in FIG. may be fitted into the outer peripheral surface of the inner steel pipe 32 in an annular shape.

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 O-ring and the water-stopping rubber seal were always sealed not only during welding but also during propulsion, but in the present invention, only the 01J ring was used during propulsion. Even if there is a small amount of water leaking at this time, it will not cause difficulties in the propulsion work, but if water leaks during welding, it may cause welding defects. At this time, it is sealed with a hollow tube.

Therefore, according to the present invention, even if the O-ring is damaged by earth and sand during the propulsion movement of the propulsion steel pipe and even a small amount of groundwater leaks into the propulsion steel pipe, the sleeve and the propulsion steel pipe can be welded together with the annular tube. By completely sealing the gap between the front and rear propulsion pipes, welding can be performed under good conditions without the influence of moisture. Moreover, welding of the forward and rear propulsion steel pipes was conventionally done using multiple segments. However, with the present invention, it is now possible to weld the ends of both propulsion steel pipes by directly butting them together, which not only simplifies welding work, but also reduces thermal distortion during welding. This resulted in an excellent joining method.

[Brief explanation of the drawing]

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 an enlarged sectional view of section C in Fig. A, Fig. 4 is a sectional view showing the state in which the tube is attached, Fig. 5 is a sectional view showing the state after welding, and Fig. 6 is a sectional view showing the state in which the inner steel pipes are butted together. FIG. 7 is a sectional view showing a specific example, and FIG. 7 is a perspective view showing a state in which the bonding is completed. In the drawing, 30 is a front propulsion steel tube, 31 is a rear propulsion steel tube, 32.33 is an inner steel tube, 38°39 is an outer tube section, 40 is a sleeve, 4L42 is a 01J ring, 47 is an intermediate jack, 49 is a circular tube.

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. An Oj song is interposed between the sleeve that is slidably fitted to the rear propulsion steel pipe, and dirt and water are removed when the front and rear propulsion steel pipes alternately move forward. When the rear propulsion steel pipe is brought close to the front propulsion steel pipe and these inner steel pipes are welded together, a sleeve is installed between the inner steel pipe of the rear propulsion steel pipe and the sleeve. The rubber tube is inflated by pressurizing fluid into the annular rubber tube so that it comes into close contact with the rear propulsion steel tube and the sleeve, and water leaking from the O-ring is removed from the rubber tube. 1. A method for joining a middle pressed portion of a propulsion steel pipe, characterized in that the two propulsion steel pipes are welded together while being sealed with a tube.