JP4139350B2 - Two-stage propulsion method - Google Patents

Description

  The present invention relates to a two-stage propulsion method, and more particularly, to a two-stage propulsion method in which a buried pipe is constructed in different forms in a first half section and a second half section of one propulsion section.

The basic work of the general propulsion method is to push the excavator and the buried pipe connected to the rear end of the excavator into the ground from the inner wall of the starting shaft excavated in the ground, and use the excavator to The buried pipe will be propelled and buried in the excavated tunnel. If the tip of the buried pipe row connected to the excavator is propelled to the reaching shaft, the propulsion work for one section is completed.
In the normal propulsion method, one type of buried pipe made of steel pipe or fume pipe is constructed over the entire propulsion section.
Apart from this, a construction method called a double pipe propulsion construction method is known. In the double-pipe propulsion method, the first half of the propulsion section close to the starting shaft is buried in a double with a large-diameter outer pipe made of steel pipe and a small-diameter inner pipe made of fume pipe. A pipe will be constructed, and only the inner pipe will be constructed in the latter half of the section near the shaft. The outer pipe is constructed only in the first half section, and the inner pipe is constructed over the entire length of the first half section and the second half section. In the first half section, since the inner pipe and the outer pipe are propelled and buried in a double state, it is called a double pipe propulsion method.

The double-pipe propulsion method is an effective method for preventing excessive fluctuation or collapse of the ground when a structure such as a railway line exists above the ground in the first half section. In addition, in the work of propelling and embedding the inner pipe in the second half section, the resistance from the ground and earth pressure are not applied to the inner pipe that moves in the inner space of the outer pipe in the first half section, so the overall resistance is greatly reduced. However, there is an advantage that the propulsive force is small. A long-distance propulsion method that cannot be sufficiently constructed with one type of buried pipe is possible. The function of protecting the inner pipe from being damaged by pressure, vibration, or impact applied from an upper structure such as a railroad track during and after the construction can be performed.
Patent Document 1 discloses a technique in which a drilling device used in a double pipe propulsion method is provided with a rotary excavator whose outer diameter is variable so that it can be adapted to both the outer pipe and the inner pipe. Has been. In this technology, when a small-diameter inner pipe is propelled and embedded in the latter half section, there is an advantage that an excessive gap is not generated between the outer circumference of the inner pipe and the ground by setting the outer diameter of the excavation small. . It is not necessary to inject a backfill material between the inner pipe and the ground.

In Patent Document 2, in the latter half section of the double pipe propulsion method, a lubricant is injected between the outer periphery of the inner pipe and the ground, thereby smoothly propelling the inner pipe and reducing the added propulsive force. Technology is shown.
Japanese Patent No. 2746866 Japanese Patent No. 2754172

In the conventional double pipe propulsion method, there is a problem that the material cost of the buried pipe is high, work is troublesome, and work efficiency is inferior.
As described above, since the outer pipe and the inner pipe are doubled in the first half of the propulsion section, naturally, the material cost of the buried pipe is also doubled. The construction cost is high compared to the normal propulsion method.
In the first half section, in the operation of connecting a new buried pipe to the rear end of the buried pipe row, each of the new inner pipe and the outer pipe is connected to the rear end of the buried pipe row in a doubled state. As a result, it takes time and effort. When applying a propulsive force to the buried pipe row with a main jack installed in the starting shaft, it is difficult to apply a propulsive force to the inner and outer double buried pipes. Usually, a propulsive force is applied only to the outer tube, but it is technically difficult and troublesome to ensure that the propelling force is applied only to the outer tube outside the inner tube.

Further, in the first half section, it is difficult to perform the lubricant injection work for reducing the propulsion resistance. In order to reduce the propulsion resistance, a lubricant must be injected between the outer periphery of the outer tube and the ground. However, an inner tube exists inside the outer tube. In order to connect the lubricant supply pipe introduced into the inner space of the inner pipe to the outer pipe through the inner pipe, it is necessary to accurately match the penetration position of the inner pipe with the connection position to the outer pipe. . This is a very time-consuming and technically difficult task. If the lubricant is not supplied in the first half section, the outer tube has a large diameter, so that the contact area with the ground is large and the ground resistance tends to increase. Propulsion cannot be performed smoothly, or excessive thrust is required.
Because of these problems, the double-pipe propulsion method was thought to be a costly propulsion method that required labor and technology for construction, and had poor work efficiency.

  An object of the present invention is to eliminate the problems of the conventional double pipe propulsion method, to facilitate the construction, improve the work efficiency, and reduce the construction cost.

The two-stage propulsion method according to the present invention is
Two-stage propulsion method in which the first buried pipe is constructed in the first half section on the starting shaft side and the second buried pipe is constructed in the latter half section on the reaching shaft side among the propulsion sections from the starting shaft to the reaching shaft in the ground. The first buried pipe is connected to the excavator for excavating the ground without arranging the second buried pipe, and is propelled from the starting shaft into the ground, and the first half section is moved to the first half section. After the first half propulsion step (a) for propelling the buried pipe and the first half propulsion step (a), the connection between the excavator and the first buried pipe is released, and the buried pipe is disposed in the ground from the starting shaft. The second buried pipe connected to the excavator through the inside of the first buried pipe is propelled together with the excavator from the row tip of the first buried tube into the ground, and reaches the reach shaft from the row tip of the first buried pipe. including a late promotion step (b) to promote embedding of the second buried pipe in the second half section In the second half propulsion step (b), the second buried pipe extends from the rear end of the second buried pipe connected to the excavator to the rear end of the first buried pipe inside the first buried pipe. A step of arranging a large number of thrust transmission members composed of steel frame blocks having a length sufficiently shorter than the length thereof in an axial direction, and a second embedding through the thrust transmission member by a main push jack installed in the starting shaft Applying a thrust to the pipe and the excavator,
It is characterized by that .

[Scope of application of the two-stage propulsion method]
Basically, it can be applied to the construction environment and construction conditions where the normal double pipe propulsion method is applied.
Specifically, use the tunnel space constructed in the ground such as water and sewage pipes, gas pipes, power wiring pipes, information communication line pipes, material transport pipes, and composite pipes of these pipes and wiring. It can be applied to the usage.
[Promotion section]
Basically, it is set in the same manner as the normal propulsion method or double pipe propulsion method.

The propulsion section is a section between the starting shaft and the reaching shaft excavated in the direction perpendicular to the ground. The two-stage propulsion method can be preferably applied when constructing a sewer underground in the first half of this propulsion section with railroad tracks or ground structures.
Even in the case of ordinary ground where there is no railway track or the like, the two-stage propulsion method can be preferably applied even when a buried pipe is constructed over a long distance in one propulsion section.
The propulsion route of the propulsion section, that is, the construction route of the buried pipe, is not only when the entire length is a horizontal straight line, but also when there is an inclination with a vertical difference in height or when it is a curve such as an arc, a straight line and a curve are mixed. There is also a case.

At both ends of the propulsion section, a starting shaft and a reaching shaft are constructed. Usually, the starting shaft has a relatively large space because it installs a jack jack or the like, or carries an excavator, a buried pipe or the like. The reaching shaft may be a smaller space than the starting shaft. When removing excavators etc., a space is needed to make it possible. If the excavator is not removed, an existing manhole can be used. The underground part of the building or civil engineering structure can also be used for the starting shaft and the reaching shaft.
[Built pipe]
Basically, the same material and structure as the buried pipe adopted in the normal propulsion method can be applied.

The material of the buried pipe includes a steel pipe, a steel pipe reinforced by welding a rib or a reinforcing frame, a concrete pipe, a reinforced concrete pipe, a fume pipe, an FRP pipe, a synthetic resin pipe, a ceramic pipe, and the like. A composite tube in which a plurality of material layers are laminated can also be used. From these pipe materials, pipe materials suitable for the required performance of the first buried pipe and the second buried pipe may be combined.
The diameter and length of the buried pipe also differ depending on the difference in materials and construction conditions. Usually, the aperture defined by the inner diameter can be set in the range of 800 to 3000 mm. The length can be set in the range of 0.6 to 4.0 m.
The first buried pipe uses a pipe material having a relatively large diameter and excellent proof stress. For example, a steel pipe is used. A pipe material having a relatively small diameter is used for the second buried pipe. Usually, since the second half section in which the second buried pipe is constructed is long, an inexpensive pipe material is preferable. A tube material that can be used without any special additional processing on the inner surface is preferred. For example, in the case of sewerage, a fume pipe is used.

The outer diameter of the second buried pipe is made smaller than the inner diameter of the first buried pipe. The more the gap between the inner periphery of the first embedded tube and the outer periphery of the second embedded tube is, the easier the second embedded tube passes through the inside of the first embedded tube. However, since the outer diameter of the second buried pipe is reduced, a large gap is likely to be generated between the outer circumference of the second buried pipe and the ground in the excavator having the same excavation diameter as the construction of the first buried pipe. In order to solve this problem, it is effective to use an excavator having a variable excavation diameter and to set a wide variable range of the excavation diameter. Usually, the radial gap between the inner circumference of the first buried pipe and the outer circumference of the second buried pipe can be set to 10 to 200 mm on one side.
A connecting structure such as a fitting shape or an engaging shape for connecting the embedded tubes back and forth can be provided at the end of the embedded tube. It is also possible to provide a sealing structure that enhances the sealing performance to prevent the intrusion of earth and sand and groundwater from the connection point.

[Digging machine]
Basically, the same material and structure as the excavator used in the normal propulsion method can be applied.
Among the excavators, a mechanism that forms a tunnel for excavating the ground and propelling the buried pipe can be provided with a rotary excavator that rotates with a excavation bit and an excavation blade on the front surface. A consolidation cone can be provided to consolidate the ground to the surroundings and expand the tunnel. A muddy water supply device that ejects muddy water to the ground and discharges the mud with the muddy water can be provided.
It is preferable that the excavation diameter of the excavator with such various excavation structures is variable. For example, the technology disclosed in Japanese Patent No. 2746866 can be applied to the structure of the excavator having a variable excavation diameter. Specifically, a part or the whole of the excavation bit and the excavation blade only needs to be able to advance and retreat in the radial direction of the excavator. In order to move the excavation bit forward and backward, various operation mechanisms such as a hydraulic mechanism, an electromagnetic actuator, a link mechanism, a cam mechanism, and a gear mechanism can be employed.

If the excavating diameter of the excavator is continuously variable within a certain range, it is easy to cope with a buried pipe having an arbitrary outer diameter that varies depending on the construction conditions. It is desirable that the excavation diameter is variable at least in two stages, that is, the excavation diameter corresponding to the first buried pipe used for construction and the excavation diameter corresponding to the second buried pipe.
By using an excavator with a variable excavation diameter, there is no excessive gap between the second buried pipe and the surrounding ground in the latter half section where the second buried pipe is propulsion buried. The propulsion of the second buried pipe can be carried out accurately and stably, and the operation of filling the gap by injecting the backfilling material becomes unnecessary.
The rear end of the excavator is provided with a structure that can connect both the first buried pipe and the second buried pipe. A normal excavator has a connection structure for connecting the buried pipe. Specifically, for example, the peripheral wall material is slightly protruded at the rear end of the excavator, and the buried pipe is inserted and connected there. Two types of connection structures such as a structure corresponding to the diameter of the first buried pipe and a structure corresponding to the diameter of the second buried pipe may be provided.

Specifically, the second embedded pipe can be connected by detachably adding a ring material for reducing the diameter to the connection structure of the first embedded pipe. The second embedded pipe can be connected to the normal connection structure of the excavator, and the first embedded pipe can be connected to the outer periphery of the rear end of the excavator through a diameter adjusting ring. Of the first buried pipes, only the leading first buried pipe can be detachably provided with a coupler that can be connected to the second buried pipe provided in the excavator. In addition, a shape and a structure necessary for connecting two types of buried pipes can be added.
A sealing structure that prevents intrusion of earth and sand or groundwater can be provided at a connection portion between the excavator and the first and second buried pipes connected to the rear end thereof.

[First half propulsion process (a)]
Basically, using the first buried pipe as the buried pipe, the same work as the normal propulsion method is performed.
The first buried pipe is connected to the excavator. The excavation diameter of the excavator can be set to the excavation diameter corresponding to the first buried pipe. From the starting shaft, the excavator and the first buried pipe are propelled into the ground. The first buried pipe is propelled and buried to a predetermined distance that becomes the end point of the first half section.
When propulsion embedding of the first buried pipe, the lubricant can be supplied between the first buried pipe and the ground from the lubricant supply pipe introduced into the first buried pipe. The first buried pipe can be provided with a lubricant supply port for discharging the lubricant to the outer peripheral surface. As the sliding material supply pipe, the lubricating material supply port, and the branch pipe structure for connecting the lubricating material supply tube to the lubricating material supply port, a structure common to the lubricating material supply structure in the normal propulsion method can be adopted. The method for supplying the lubricant can be performed in the same manner as the normal propulsion method.

[Second half promotion process (b)]
Release the connection between the excavator and the first buried pipe. The connection between the excavator and the first buried pipe is released from the internal space of the first buried pipe in the ground. It can also be made possible to release the connection from the starting shaft or from the ground.
The second buried pipe is connected to the excavator through the inside of the first buried pipe disposed in the ground from the starting vertical shaft. Only one of the second buried pipes may be connected to be propulsion embedded at a time, or a plurality of the second embedded pipes may be connected to be propulsion embedded at a time. When connecting a plurality of pipes, the front and rear buried pipes are connected together.

It is desirable to change the excavating diameter of the excavator to an excavating diameter corresponding to the second buried pipe. The excavation diameter corresponding to the first buried pipe is reduced.
The second buried pipe connected to the excavator is propelled into the ground from the row tip of the first buried pipe. If a slidable sealing member is arranged between the first buried pipe and the second buried pipe, it is possible to prevent earth and sand and groundwater from entering from the tip of the first buried pipe. The sealing member can be applied with a sealing member technique provided in an excavating machine or a buried pipe in a normal propulsion method. The sealing member can be disposed on the inner periphery of the distal end of the stationary first buried pipe.
If propulsion is performed until the rear end of the second buried pipe is close to the front end of the first buried pipe, the new second buried pipe is connected and the propulsion operation is performed again. Such a propulsion operation is repeated to construct the second buried pipe row in the second half section from the reaching shaft to the first tip of the first buried pipe row. The second buried pipe is applied to the row tip of the first buried tube or a position where it slightly enters the first buried tube side from the row tip. The second buried pipe is not constructed in the first half section near the starting shaft of the first buried pipe.

When the propulsion work is performed, the rear end of the second buried pipe is located inside the first buried pipe, so that a normal push jack installed at the starting shaft in the normal propulsion construction method is used at the rear end of the second buried pipe. It is difficult to apply driving force directly.
Therefore, a technical means for applying a propulsive force to the rear end of the second buried pipe existing inside the first buried pipe is necessary.
<Use of thrust transmission material>
The step (b-1) of arranging the thrust transmission material from the rear end of the second buried pipe connected to the excavator to the rear end of the first buried pipe inside the first buried pipe and installed in the starting shaft And a step (b-2) of applying a propulsive force to the second buried pipe and the excavator through the thrust transmission member with the main push jack.

The thrust transmission material is required to have rigidity or proof strength capable of transmitting a necessary propulsive force from the main pushing jack to the second buried pipe. A material having high mechanical strength such as steel can be used. Concrete or FRP material can also be used. A steel frame material constructed by assembling a shape steel material into a frame shape and fixing it by welding or bolt fastening can be used. Column material and pipe material can also be used.
When the distance from the main jack to the second buried pipe is long, a thrust transmission material with a comparatively short dimension that can easily be carried into the first buried pipe from the starting shaft is moved back and forth in the axial direction. It is also possible to transmit the thrust in a state where they are arranged side by side. In this case, if the thrust transmission material is approximately the same as the length of the second embedded pipe, the thrust transmission material can be increased and arranged together with the sequential connection of the second embedded pipes. A shorter thrust transmission material is easier to handle such as transport than the length of the second buried pipe. By combining the necessary number of thrust transmission materials according to the work situation, it is possible to easily cope with the construction of the second buried pipe having different dimensions.

Specifically, for example, a large number of steel frame blocks constructed in a frame shape with the above-described steel materials can be used side by side in the axial direction.
The thrust transmission member can be provided with means that can be connected and fixed in the front-rear direction. Means such as fitting, engagement, and bolt fastening can be applied. However, since the thrust transmission material only needs to be able to transmit a load only in the propulsion direction, the thrust can be transmitted without a special fixing means. Removal work after construction is easier if the thrust transmission materials are not fixed together.
Inside the first buried pipe, a rail or a guide member that supports the thrust transmission material and smoothly moves in the propulsion direction can be installed. Such rails and guide members can also be used to transport and stably support the second buried pipe.

<Use of mobile jack device>
A step (b-3) of disposing a movable jack device that is movable in the axial direction inside the first buried pipe, and a movable jack device arranged at the rear end of the second buried pipe, And a step (b-4) of applying a driving force to the pipe and the excavator.
The moving jack device is provided with a thrust generating jack that is driven by hydraulic pressure or the like to move the operating shaft back and forth in the same manner as a normal main pushing jack. A plurality of thrust generating jacks may be arranged at intervals along the circumferential direction of the second buried pipe.
The moving jack device can be provided with a moving structure capable of moving in the axial direction inside the first buried pipe. In order to support the reaction force when the thrust generating jack is operated by the first embedded pipe, a fixing means for detachably fixing the movable jack device to the first embedded pipe can be provided.

Specifically, a traveling wheel that travels on a rail laid on the bottom or bottom of the first buried pipe can be provided as the moving structure. As the fixing means, a fixing pin or a fixing bolt for fastening the structural member of the movable jack device and the rail can be detachably provided.
<Supply of lubricant>
In the latter half propulsion process of propelling the second buried pipe, the lubricant can be supplied between the second buried pipe and the ground. Specifically, a technique common to the lubricant supply in the first half propulsion process described above can be applied. However, it is not necessary to supply the lubricant to the first buried pipe row that is not propelled at this stage.
[Other processes]
After the construction of the first buried pipe and the second buried pipe is completed, a post-treatment process similar to a normal propulsion method or a double pipe propulsion method can be performed.

  For example, the sealing process can be performed on the connection portion between the second embedded pipes. A coating layer can be formed by coating on the inner surface of the second buried pipe. It is also possible to carry out in-place installation with a sheet or the like. A fixed sealing structure can be constructed between the rear end of the second buried pipe and the front end of the first buried pipe. A lining material that fills a step between the inner peripheral surface of the first embedded pipe and the inner peripheral surface of the second embedded pipe can also be applied to the inner peripheral surface of the first embedded pipe. The second buried pipe and the first buried pipe can be filled with a mortar or attached with an opening frame at a portion opened to the starting shaft and the reaching shaft. Illumination can be installed inside the first and second buried pipes, and power wiring and communication wiring can be laid.

In the two-stage propulsion method according to the present invention, in the first half section of the propulsion section, the first buried pipe is connected to the rear end of the excavator and the connector for propulsion embedding. The same work as a normal propulsion method can be performed. The work of connecting a new buried pipe to the rear end of the buried pipe row, the addition of a propulsive force by a push jack, the supply of a lubricant, and the like can be performed easily and efficiently, unlike the ordinary propulsion method.
When the propulsion process of the second half section is performed, the work of arranging the second buried pipe to the position where it is connected to the rear end of the coupler through the inside of the first buried pipe is not subjected to any resistance from the ground. Since it is an operation inside one buried pipe row, it can be done very easily and efficiently. The work of propelling and embedding the second buried pipe in the latter half section can be performed smoothly and efficiently in a state where the resistance from the ground is greatly reduced, as in the conventional double pipe propulsion method. In particular, since there is no extra second buried pipe in the first buried pipe row, the propulsive force and the operating energy can be reduced accordingly.

In the construction completion state, only the first buried pipe is constructed in the first half section, and only the second buried pipe is constructed in the second half section. Therefore, the length of the first half section is longer than the conventional double pipe propulsion method. The material for the second buried pipe corresponding to is no longer necessary, and the material cost can be reduced.
As a result, the disadvantages of the double pipe propulsion method can be eliminated without impairing the advantages of the conventional double pipe propulsion method, and the work efficiency and work quality can be significantly improved economically.

The embodiment shown in FIGS. 1 to 4 schematically shows a case where a sewer is constructed under a railroad track.
[Overview of the propulsion method]
As shown in FIG. 4, on both sides of the railway track R, the starting shaft H1 and the reaching shaft H2 are excavated on the ground E, and the buried pipe 10 is embedded in the ground E in the propulsion section from the starting shaft H1 to the reaching shaft H2. 20 is constructed.
Of the propulsion section, only the first buried pipe 10 row made of steel pipe is constructed in the first half section close to the starting shaft H1. In the second half section close to the reaching shaft H2, only the row of second buried pipes 20 made of fume pipes is constructed. The outer diameter of the second embedded pipe 20 is smaller than the inner diameter of the first embedded pipe 10. A space between the front end of the first embedded tube 10 and the rear end of the second embedded tube 20 is sealed with a sealing member 16 or the like. One continuous tunnel space from the first buried pipe 10 to the second buried pipe 20 is formed. The internal space of the first buried pipe 10 and the second buried pipe 20 is used for sewerage or the like.

In the figure, the length of the latter half section in which only the second buried pipe 20 is constructed is omitted, and actually the latter half section is considerably longer than the first half section.
In the first half section crossing the railroad track R, since the first buried pipe 10 having excellent proof stress is constructed, it is possible to effectively prevent problems such as ground fluctuation and collapse below the railroad track R.
[Construction of the first half section]
As shown in FIG. 1, the row of the first buried pipe 10 connected to the rear end of the excavator 30 and the excavator 30 is propelled and embedded from the inner wall of the starting shaft H1 toward the inside of the ground E.
Basically, the same equipment, equipment, and working method as the propulsion method using one ordinary type of buried pipe are employed.

<Digging machine>
The excavator 30 basically has the same structure as an ordinary excavator for a propulsion method.
The outer diameter of the excavator 30 that is generally cylindrical as a whole is set according to the outer diameter of the second buried pipe 20. The outer diameter is smaller than the outer diameter of the first buried pipe 10. The rotary excavator 32 provided at the tip of the excavator 30 includes a movable excavation bit 34 in addition to a normal excavation bit and an excavation blade. The movable excavation bits 34 are arranged at a plurality of locations along the outer peripheral edge of the rotary excavator 32 and advance and retract in the radial direction. Although not shown, the movable excavation bit 34 is advanced and retracted by a hydraulic actuator built in the rotary excavator 32. FIG. 1 shows a state where the movable excavation bit 34 is moved to the outside of the outer diameter of the excavator 30. The excavation diameter determined by the outer diameter of the movable excavation bit 34 corresponds to the outer diameter of the first buried pipe 10.

Although not shown, the excavator 30 measures the position of the excavator 30 by a motor and a speed reducer that rotate the rotary excavator 32, a soil removal mechanism that discharges the earth and sand excavated by the rotary excavator 32, and the excavator 30. The same mechanism and device as those of the ordinary excavator 30 are mounted, such as a surveying device to be used and a turning jack for changing the excavation direction of the excavator 30.
The first buried pipe 10 having an inner diameter larger than the outer diameter of the excavator 30 is connected to the rear end of the excavator 30 via a detachable connecting ring 14 made of steel or the like. A sliding sealing member 12 is attached to the inner periphery of the distal end of the first buried pipe 10 adjacent to the connecting ring member 14.
<Supplying lubricant>
As shown in FIG. 1, a lubricant supply pipe 60 is introduced from the ground to the inside of the first buried pipe 10 through the inside of the starting shaft H1. The lubricant supply pipe 60 is branched at a plurality of locations on the front and rear sides, and each branched tip is connected to a lubricant supply port 62 installed on the tube wall of the first buried pipe 10. Since the second embedded pipe 20 does not exist inside the first embedded pipe 10, the piping attachment from the lubricant supply pipe 60 to the lubricant supply port 62 can be easily performed.

The lubricant supplied to the gap with the ground E from the lubricant supply port 62 reduces the frictional resistance applied from the ground E when the first buried pipe 10 is propelled. Propulsion is performed smoothly, the propulsive force to be added can be reduced, and the propulsion time can be shortened.
<Promotion work>
As shown in FIG. 1, a main jack 50 is installed on the starting shaft H1. The front end of the operating shaft 52 of the main push jack 50 abuts against the rear end of the first buried pipe 10 via the abutment plate 54.
In this state, while rotating the rotary excavator 30 of the excavator 30 and excavating the ground E, the operating shaft 52 of the main push jack 50 is advanced forward, and the row of the excavator 30 and the first buried pipe 10 is moved. Push forward.

When the propulsion work for one first buried pipe 10 is completed, a new first buried pipe 10 is connected to the rear end of the first buried pipe 10 in the starting shaft H1, and the above-described propulsion is performed again. Do work. In FIG. 1, the depth of the starting shaft H1 is displayed narrower than the actual depth because of the drawing space. Actually, a sufficient margin is provided between the main push jack 50 and the rear end of the first buried pipe 10 for inserting and arranging a new first buried pipe 10.
The propulsion work of the first buried pipe 10 described above is basically not significantly different from the normal propulsion method.
When the first buried pipe 10 is propelled and buried in the entire lower region of the railway track R, the construction of the front section is completed.

[Second half section construction]
As shown in FIGS. 2 and 3, propulsion embedding of the second buried pipe 20 is performed.
<Preparation work>
The connecting ring member 14 that connects the first buried pipe 10 and the excavator 30 is removed so that the excavator 30 can move freely.
Within the row of the first embedded pipes 10, the tip side and the lubricant supply port 62 of the lubricant supply pipe 60 with respect to the branch portion are removed or closed. The lubricant supply pipe 60 is extended forward as the propulsion of the second embedded pipe 20 proceeds.

Since the second embedded pipe 20 does not exist inside the first embedded pipe 10, these operations can be easily performed in a space with a margin.
<Arrangement of second buried pipe>
The second buried pipe 20 is carried from the ground to the starting shaft H 1 and inserted into the first buried pipe 10. Only one second embedded tube 20 is inserted. The inserted second buried pipe 20 is connected to the rear end of the excavator 30.
Since the insertion operation of the second embedded pipe 20 is performed inside the row of the first embedded pipes 10 isolated from the ground E, no great resistance acts on the movement of the second embedded pipe 20. Even if a large force is not applied by the main push jack 50, the insertion work can be performed only by pushing it manually or by pulling it with a simple winch device. Of course, it is also possible to sequentially push the second embedded pipe 20 forward using the main pushing jack 50. In this case, the pushing force applied by the main pushing jack 50 may be much smaller than the propulsion work.

<Arrangement of thrust transmission material>
The thrust transmission member 40 is disposed at the rear end of the second buried pipe 20 connected to the rear end of the excavator 30 inside the first buried pipe 10.
As shown in detail in FIG. 3, the thrust transmission member 40 is assembled and welded in a frame shape in the vertical and horizontal directions or in an oblique direction to form a rectangular parallelepiped box frame. The thrust transmission material 40 is carried into the start shaft H1 from the ground using a crane or the like. Furthermore, the thrust transmission material 40 carried into the first buried pipe 10 from the starting shaft H <b> 1 is disposed at the rear end of the second buried pipe 20. As shown in FIG. 3, the thrust transmission member 40 is supported and slid on a guide member 42 made of a round steel bar welded along the axial direction to the left and right near the bottom of the first buried pipe 10. If it moves, the thrust transmission member 40 can be easily moved. This guide member 42 can also fulfill the function of supporting the second buried pipe 20 and smoothing the movement.

The thrust transmission member 40 is disposed from the rear end of the second buried pipe 20 to the rear end of the first buried pipe 10 that opens to the starting shaft H1. A part of the thrust transmission member 40 protrudes rearward from the rear end of the first buried pipe 10.
<Promotion of the second buried pipe>
Basically, the same work procedure as the propulsion work of the inner pipe, that is, the second buried pipe 20 in the conventional double pipe propulsion method can be applied.
As shown in FIG. 2, the movable excavation bit 34 of the excavator 30 is withdrawn to the center side. The excavation diameter corresponds to the outer diameter of the excavator 30 and the second buried pipe 20.

The operating shaft 52 of the main push jack 50 is brought into contact with the rear end surface of the thrust transmission member 40. As shown in FIG. 3, a pair of right and left main pushing jacks 50 are brought into contact with the left and right portions of the thrust transmission member 40. When the operating shaft 52 of the main push jack 50 is advanced, a propulsive force is applied to the second buried pipe 20 and the excavator 30 via the thrust transmission member 40. If the rotary excavator 32 of the excavator 30 is driven to rotate, the ground E is excavated as the excavator 30 is propelled.
The lubricant supply pipe 60 introduced into the starting shaft H1 is laid in the row internal space of the second buried pipes 20. The lubricant supply pipe 60 is connected to the lubricant supply port 62 provided on the peripheral wall of the second embedded pipe 20 in front of the row of the first embedded pipes 10.

While excavating the ground E with the rotary excavator 32 of the excavator 30, the row of the excavator 30 and the second buried pipe 20 is propelled by the propulsive force applied by the main push jack 50. A lubricant is supplied between the outer peripheral surface of the second buried pipe 20 and the ground E to reduce the resistance from the ground E.
After one second buried pipe 20 is propelled, a new second buried pipe 20 is sequentially connected to the rear end of the row of the second buried pipe 20 that has already been promoted in the starting shaft H1. At this time, in a state where the thrust transmission material 40 is once removed, a new second embedded pipe 20 is inserted, and thereafter, the thrust standing material 40 is rearranged in the same manner as described above.
When the second embedded tube 20 is propelled through the center of the stationary first embedded tube 10, the second embedded tube 20 is in contact with the sliding sealing member 12 provided on the inner peripheral surface of the first embedded tube 10. Since it slides, the 2nd buried pipe 20 is propelled, always maintaining a good sealing state.

The propulsion of the second embedded pipe 20 propels the second embedded pipe 20 existing forward from the vicinity of the tip of the first embedded pipe 10 and the thrust transmission member 40 disposed behind the second embedded pipe 10. Compared with the conventional double pipe propulsion method in which the second embedded pipe 20 is disposed in the entire internal length, the total weight or inertia weight of the material to be moved is reduced. The main push jack 50 can be operated easily and smoothly.
[End of propulsion method]
As shown in FIG. 4, when the second buried pipe 20 is arranged up to the reaching shaft H2, the propulsion work is completed. Subsequent operations can be performed in the same manner as in the normal propulsion method.

The excavator 30 may be removed from the head of the second buried pipe 20 and removed from the reaching shaft H2 to the ground. In the starting shaft H1, the equipment for propulsion work such as the main jack 50 is removed. Inside the first buried pipe 10, the thrust transmission material 40 is removed. Inside the row of the second buried pipes 20, an operation of removing the lubricant supply pipe 60 and closing the lubricant supply port 62 is performed. A coating layer can be applied to the inner surfaces of the second embedded pipe 20 and the first embedded pipe 10. It is also possible to perform a process of placing mortar between the inner walls of the starting shaft H1 and the reaching shaft H2 and the ends of the first buried pipe 10 and the second buried pipe 20 to close them.
The underground underground pipe structure completed in this way can be used for sewerage and the like. In the lower region of the railroad track R, there is a first buried pipe 10 made of a steel pipe with excellent proof stress, so even if pressure applied from the structure of the railroad track R or ground pressure that fluctuates due to train passage acts, Can withstand enough.

[Use of moving jack device]
The embodiment shown in FIGS. 5 to 7 is different from the embodiment using the thrust transmission material 40 in the construction process of the second embedded pipe 20. Since the basic technical contents including the first half process are the same as those in the above embodiment, the differences will be mainly described.
As shown in FIG. 5, the work of constructing the first buried pipe 10 from the starting shaft H1 to the first half section is common to the above embodiment.
Thereafter, the connection between the first buried pipe 10 and the excavator 30 is released, the second buried pipe 20 is connected to the rear end of the excavator 30, or the lubricant supply pipe 60 laid on the first buried pipe 10. The operation of sequentially re-laying the lubricant supply port 62 on the second buried pipe 20 can be performed in the same manner as in the above embodiment.

In this embodiment, instead of disposing the thrust transmission member 40 at the rear end of the second embedded pipe 20, a moving jack device 80 is installed.
As shown in detail in FIGS. 6 and 7, the moving jack device 80 has a plurality of thrust generating jacks 90 mounted on a main body structure 82 constructed of steel. The tip of the operating shaft 92 of the thrust generating jack 90 is in contact with the rear end surface of the second embedded pipe 20. As shown in FIG. 7, thrust generating jacks 90 are arranged at equal positions in all directions on the rear end surface of the second embedded pipe 20. There is a space penetrating in the axial direction in the center of the main body structure 82, and various piping cables to the lubricant supply pipe 60 and the excavator 30 can be passed through this space.

As shown in detail in FIG. 7, a guide rail 70 made of L-shaped steel is symmetrically welded near the inner bottom of the first buried pipe 10 in a pair of left and right. As shown in FIG. 6, the guide rail 70 is installed over substantially the entire length of the first buried pipe 10.
A traveling roller 84 is attached to the lower end of the main body structure 82. A travel roller 84 is placed on the upper surface of the guide rail 70. The entire moving jack device 80 is supported by the guide rail 70 via the traveling roller 84. When the moving jack device 80 is moved in the axial direction, the traveling roller 84 smoothly rotates on the guide rail 70. The moving jack device 80 can be easily moved with a relatively small force.

At the lower end of the main body structure 82, a fixing pin 86 that can be inserted and removed is attached at a position facing the inner surface of the guide rail 70. Pin insertion holes 72 pass through the inner surface of the guide rail 70 at regular intervals. After the movable jack device 80 is moved to a desired position, the movable jack device 80 is fixed to the guide rail 70 by inserting the fixing pin 86 into the pin insertion hole 72 of the guide rail 70 from the main body structure 82.
As shown in FIG. 6, after the moving jack device 80 is moved near the rear end of the second embedded pipe 20, it is fixed to the guide rail 70 with a fixing pin 86. Thereafter, the thrust generating jack 90 of the moving jack device 80 is operated, and a driving force is applied to the second embedded pipe 20 by the operating shaft 92.

As shown in FIG. 5, while excavating the ground E with the excavating machine 30, the second buried pipe 20 and the excavating machine 30 to which propulsive force is applied by the moving jack device 90 propel the inside of the ground E. The reaction force from the ground E is received by the guide rail 70 and the first buried pipe 10 via the fixed pin 86 of the moving jack device 90.
Once the propulsion of the second buried pipe 20 is completed, the moving jack device 90 is once pulled back from the rear end of the first buried pipe 10 to the starting shaft H1, and then the new second buried pipe 20 is moved to the second It connects with the rear end of the 2nd buried pipe 20 already propelled through the inside of 1 buried pipe 10. Thereafter, the moving jack device 80 is disposed at the rear end of the second embedded pipe 20 in the same manner as described above, and the same propulsion work as described above is performed.

In the embodiment described above, the propulsion jack 50 installed in the starting shaft H1 is propelled over a long distance to the second buried pipe 20 via the thrust transmission member 40 arranged inside the first buried pipe 10. There is no need to transmit power. Since the propulsive force is always applied by the moving jack device 90 disposed at the rear end of the second embedded pipe 20, a strong propulsive force can be transmitted efficiently.
[Another construction method]
In the above embodiment, the first half section is constructed by connecting only the first buried pipe 10 to the excavator 30. However, the first buried pipe 10 and the second buried pipe 20 are both connected to the excavator 30. It can also be left. In this case, the same construction technique as the construction of the first half section in the normal double pipe propulsion method is applied. Of the first buried pipes 10 connected to the rear end of the excavating machine 30, the second buried pipes 20 may be arranged in only one or a part of the first buried pipes 10, or all the first buried pipes 10 Two buried pipes 20 may be arranged.

  The construction of the second half section is a state in which the second embedded pipe 20 is arranged inside the first embedded pipe 10 at the start time. Thereafter, the work of propelling the excavator 30 and the second buried pipe 20 is common to the above embodiment. If the second buried pipe 20 is arranged from the first stage to the rear of the first buried pipe 10 near the rear of the first buried pipe 10 in the construction of the second half section, the work of applying a propulsive force to the second buried pipe 20 is performed. Easy to do. In the first stage, it is possible to apply a propulsive force directly to the rear end of the second embedded pipe 20 with the main push jack 50. Even when the thrust transmission member 40 is inserted and arranged, the number of the thrust transmission members 40 used can be reduced and labor can be saved.

  The two-stage propulsion method according to the present invention can be effectively applied to, for example, construction of a sewer under the railroad track. Without adversely affecting the railway track, without being adversely affected by the railway track, the construction of the buried pipe can be carried out simply and efficiently and economically.

Sectional drawing which shows the construction state of the first half section used as embodiment of this invention Sectional view showing the construction status of the second half section Side view showing arrangement structure of thrust transmission material in cross section orthogonal to previous figure Sectional view showing the end state of the propulsion method Sectional drawing which shows the construction state of the latter half area in another embodiment Detailed sectional view of the main part in the previous figure Partially cutaway side view in a cross section orthogonal to the previous figure

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 1st buried pipe 12 Sliding sealing member 14 Connection ring material 16 Connection part sealing member 20 2nd buried pipe 30 Excavator 32 Rotating excavator 34 Movable excavation bit 40 Thrust transmission material 50 Main pushing jack 52 Actuating shaft 60 Sliding Material supply pipe 62 Lubricant supply port E Ground R Railway track

Claims (3)

Two-stage propulsion method in which the first buried pipe is constructed in the first half section on the starting shaft side and the second buried pipe is constructed in the latter half section on the reaching shaft side among the propulsion sections from the starting shaft to the reaching shaft in the ground. Because
A first half propulsion step (a) in which the first buried pipe is connected to an excavating machine for excavating the ground, propelled into the ground from the starting vertical shaft, and the first buried pipe is propelled and buried in the first half section;
After the first half propulsion step (a), the connection between the excavator and the first buried pipe is released, and the excavator is connected to the excavator through the first buried pipe disposed in the ground from the starting shaft. The latter half propulsion step of propelling and burying the second buried pipe in the latter half section from the row leading end of the first buried pipe to the reaching shaft by propelling the second buried pipe together with the excavator from the row leading end of the first buried pipe and (b),
Only including,
In the latter half propulsion step (b), the length of the second buried pipe extends from the rear end of the second buried pipe connected to the excavator to the rear end of the first buried pipe inside the first buried pipe. A step of arranging a large number of thrust transmission members made of steel frame blocks having a length sufficiently shorter than the length of the steel frame block in the axial direction, and a second buried pipe through the thrust transmission member with a push jack installed in the starting shaft And applying a driving force to the excavator,
This is a two-stage propulsion method. First half propulsion step (a) includes the lubricant supply pipe, which is introduced into the interior of the first buried pipe, as engineering supplies lubricant between the first buried pipes and the ground,
The second half propulsion step (b) is a front side of the construction site of the first buried pipe, and from the lubricant supply pipe introduced into the second buried pipe, between the second buried pipe and the ground. lubricant also includes a more engineering and supplies,
The two-stage propulsion method according to claim 1 . As the excavator, an excavator whose excavating diameter is variable between an excavating diameter corresponding to the first buried pipe and an excavating diameter corresponding to the second buried pipe having an outer diameter smaller than the inner diameter of the first buried pipe is used. ,
In the first half propulsion step (a) , the excavator is propelled by setting the excavation diameter of the excavator to the excavation diameter corresponding to the first buried pipe,
In the latter half propulsion step (b) , after changing the excavation diameter of the excavator from the excavation diameter corresponding to the first buried pipe to the excavation diameter corresponding to the second buried pipe, the excavator is propelled .
The two-stage propulsion method according to claim 1 or 2 .

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