JPS5841400B2 - 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 steel pipes, as shown in Figure 1, an intermediate jack 4 is installed between the two propulsion steel pipes 2 and 3 in the ground 1, and the rear propulsion steel pipe 3 is The front propulsion steel pipe 2 as a fixed end is advanced by the intermediate jack 4, and then the rear propulsion steel pipe 3 is pushed forward by the main push jack 6 in one of the pits 5, and the main push jack 6 and the intermediate jack 4 are moved forward. By applying a kind of oscillating motion to the propulsion steel pipe by driving it alternately, the original push jack 6
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 force.

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 for joining the intermediate pressed portions of the propulsion steel pipes described above is shown in FIG.
, each of the propulsion steel pipes 2 on the front side and the rear side from the outer pipe part 14.15 formed by the outermost steel pipe 10.11 and the mortar 12.13 filled between this and the inner steel pipe. 3 is 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 achieve a seal with the water stop rubber gasket 20, it is necessary to press it. Therefore, an intermediate jack (not shown) installed between the inner steel pipes 8 and 9 of both propulsion steel tubes 2 and 3 and a water stop rubber gasket are used. A short turnbuckle (not shown) on the side wood is installed between the 20 and the rubber gasket for water stopping when the intermediate jack is used to alternately propel both the front and rear propulsion steel pipes. 20 is used for sealing.

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,
9 and welding the segment 23 and the inner tube portions 8, 9 at these abutting portions 24, 25,
The inner steel pipe 8 on the front side and the rear side via the segment 23,
We are trying to unite nine comrades.

In such a conventional joining method, attaching the short turnbuckle and the long turnbuckle 22 for pressing the waterproof rubber backing 20 requires complicated steps such as reassembly and insertion of multiple segments 23. Not only is it a lot of work, but the amount of welding between the plurality of segments 23 and the inner steel pipes 8, 9 is enormous, and welding distortion has 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 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. After sealing and inserting an annular water stopper made of an elastoplastic material between the rib protruding in the radial direction inside the sleeve and the outer pipe end surface of the rear propulsion steel pipe, the rear propulsion steel pipe is sealed. Move the steel pipe forward toward the forward propulsion steel pipe,
The forward movement of the rear propulsion steel pipe crushes the water stop material in the axial direction between the rib and the end face of the outer pipe portion, and the water leaking from the 01J ring is sealed with the water stop material. In this method, the inner steel pipes of both 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 8. Figs. 3 to 7 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 (4 inner steel pipes 32.3
3, outer steel pipe 34°35 and this and inner steel pipe 32.3
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 tube 30 and the rear propulsion steel tube 31 move forward alternately, the sleeve 40 that slides and fits on the outer peripheral surface of the rear propulsion steel tube 31 is fixed to the front propulsion steel tube 30. Two 01J rings 41 and 42 are interposed between the sleeve 40 and the propulsion steel pipe 31 on the rear side to prevent dirt and water from leaking into the respective propulsion steel pipes 30 and 31. .

Of the two O'Jings 41 and 42, one O'Jing 1 is accommodated in a groove 43 formed in the outer steel pipe 35 as shown in FIG. C
As shown in FIG. 3, it is accommodated in a groove 44 formed in the outer steel pipe 35.

In order to alternately move the forward propulsion steel pipe 30 and the rear propulsion steel pipe 31 forward, an intermediate jack 47 is installed between both propulsion steel pipes 30, 31 via fittings 45, 46, By driving the intermediate jack 47, 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 drive 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 5, 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 spiral movement, thereby propelling the propulsion steel pipe 30, 31 underground.

During this propulsion movement, the two 01J rings 41 and 42 seal off the inflow or leakage of earth and sand and water from the outside.

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, as shown in FIG. An annular water stop material 49 that is elastically or plastically deformable and made of bituminous impregnated urethane foam or butyl rubber is bonded to the inner peripheral surface of the sleeve 40 with an adhesive.

Then, the propulsion steel pipe 3 on the rear side is
1 is moved forward toward the forward propulsion steel pipe 30, and as shown in FIG.
2 and the inner steel pipe 33 of the propulsion steel pipe 31 on the rear side are butted against each other.

As a result, the annular water stop material 49 is crushed in the axial direction between the rib 48 and the outer end surface of the propulsion steel pipe 31 on the rear side, as shown in FIG. sleeve 4
0 and the inner steel pipe 33.

Therefore, even if a small amount of water leaks through the 01J ring 4L42, it is sealed by the water stop material 49.

In this way, the pipe ends 53 of both propulsion steel pipes 30 and 31 can be welded in a state where moisture leakage is completely prevented by the OIJ song L42 and the annular water stop material 49.

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

This state is shown in FIG.

FIG. 5 is a diagram showing a case in which an annular water stop material 49 is bonded to the end surface of the outer tube portion 39 of the rearward propulsion steel tube 31 with an adhesive as another specific example of the present invention. Part 39
Such a method may be used as long as the water stop material 49 is inserted between the end face of the holder.

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 a water stopper 49 as shown in FIG. 52 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. 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 water-stopping rubber gasket were always used to seal the water not only during welding but also during propulsion, but in the present invention, only the O-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. In this case, it is sealed with a water-stopping material made of elastoplastic material.

Therefore, according to the present invention, even if the 01J 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 annular water-stopping material can be used to connect the sleeve and the propulsion pipe during welding. By completely sealing the gap between the steel pipe and the steel pipe, welding can be performed under good conditions without the influence of moisture. Moreover, welding of the front and rear propulsion steel pipes conventionally required multiple welding steps. Previously, this was done by inserting segments, but with the present invention, it is now possible to weld the pipe ends of one propulsion steel pipe directly against each other, which not only simplifies the welding work but also reduces the heat generated during welding. This resulted in an excellent joining method with no distortion.

[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.
An enlarged cross-sectional view of part C in Figure A, Figure 4 is a cross-sectional view showing the water-stopping material installed, Figure 5 is a cross-sectional view showing another example of how to attach the water-stopping material, and Figure 6 is welding. 7 is a sectional view showing another specific example for butting inner steel pipes together; FIG. 8 is a perspective view showing the finished state of joining; In the drawing, 30 indicates forward propulsion. 31 is the rear propulsion steel pipe, 32, 33 is the inner steel pipe, 38° and 39 are the outer pipe parts, 40 is the sleeve, 4L42 is the 01J ring, 47 is the intermediate jack, and 49 is the annular water stop material.

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 O-ring is interposed between the sleeve and the rear propulsion steel pipe, which are slidably fitted to each other, so that earth and sand can be removed during alternate forward movement of the front and rear propulsion steel pipes. After sealing the inflow of water and inserting an annular water stopper made of an elastoplastic material between a rib protruding in the radial direction within the sleeve and an end surface of the outer pipe portion of the rear propulsion steel pipe,
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 water stop material to be pivoted between the rib and the end surface of the outer pipe portion. The inner steel pipes of both the propulsion steel pipes are welded together while the inner steel pipes of the two propulsion steel pipes are crushed in the direction and the water leaking from the 01J ring is sealed with the water stop material. Method.