JP3574323B2 - Middle push pipe for propulsion method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a center push pipe for a propulsion method adopted when a pipeline is constructed underground.
[0002]
[Prior art]
The propulsion method is a method in which a propulsion pipe is sequentially added to the rear end of an excavator, and a main jack is installed at the rear end to apply propulsion force to push the preceding propulsion pipe as the excavation progresses. Has been adopted. Recently, the total length of the propulsion pipe is approaching several hundred meters to 1,000 meters. If the total length of the propulsion pipe becomes large in this way, the propulsion power becomes excessive and may exceed the strength of the propulsion pipe or the strength of the reaction wall in the starting pit. The intermediate pressing method is used in which the intermediate pressing jack is divided and loaded to protrude.
[0003]
As shown in FIG. 10, a conventional center-pressed tube used in the above-described center-pressing method is a center-pressed tube main body 1 generally called a center-pressed T-tube and a center-pressed slide tube called a center-pressed S-tube. The center push tube 2 is fitted to the outside of the front end of the center push tube main body 1 and is slidable in the central axis direction.
[0004]
Two annular seal members 3, 3 are provided on the outer peripheral surface of the center push tube main body 1 (see FIG. 11), and are in close contact with the inner peripheral surface of the center push slide tube 2. A lubricant injection hole 4 is provided between the two seal members 3. An intermediate push jack 6 is interposed between the front end of the intermediate push tube main body 1 and the inward flange 5 of the intermediate push slide tube 2. The above middle push tube is provided for use by being interposed between the standard propulsion tubes before and after the middle push tube.
[0005]
When the propulsion method is carried out using the middle push pipe as described above while also using the middle push method, in order to reduce the propulsion resistance on the outer peripheral surface of the push pipe, the propulsion pipe is inserted from the inside of the standard push pipe and the middle push pipe. A lubricant is injected into the outer peripheral surface.
[0006]
[Problems to be solved by the invention]
Since the injection pressure of the above-mentioned lubricating material is generally set to a pressure obtained by adding 0.2 to 0.3 kgf / cm ² to the groundwater pressure, the injection pressure increases as the burial depth of the propulsion pipe increases. As a result, not only the groundwater pressure acting on the fitting portion of the center-pushed pipe main body 1 and the center-pushed slide pipe 2 but also the pressure of the sliding material increases, so that water leakage or water leakage occurs in the center-pushed pipe. Sand leakage and the like may occur, resulting in suspension of construction and inability to proceed.
[0007]
The first factor of such a problem in the conventional center-pushed tube is that the gap S (see FIG. 11) at the fitting portion between the center-pushed tube main body 1 and the center-pushed slide tube 2 is too large. For example, when the nominal diameter is 1000 mm, the gap S is 9 mm, and if a deviation occurs during propulsion, the gap S may be as large as 12 mm.
[0008]
The second factor is that increasing the diameter of the seal members 3, 3 in order to cope with the above-mentioned change in the size of the gap S requires the fitting between the center-pushed tube main body 1 and the center-pushed slide tube 2. Therefore, the diameter cannot be increased beyond a certain value.
[0009]
The third factor is that it is not possible to take an adventurous countermeasure such as adding a sealing member when there is a risk of water leakage or sand leakage or removing it when unnecessary.
[0010]
Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a central push pipe for a propulsion method which is excellent in waterproofness against water leakage and sand leakage.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention relates to a middle push tube, wherein a middle push tube is fitted outside the front end of the middle push tube body so as to be slidable in a central axis direction of the middle push tube body. An annular seal member is attached to the fitting surface between the main body and the middle push slide tube , and a middle push jack is attached between the front end of the middle push tube main body and the flange of the middle push slide tube to perform other propulsion. In the middle construction pipe for a propulsion method used interposed between pipes, a reinforcing ring made of a formed steel plate having a circumferential sealing groove is integrally provided on an outer peripheral surface of a front end of the middle construction pipe main body, and the seal is provided. A configuration in which the above-described seal member is mounted in the groove is employed.
[0012]
Along with providing a cylindrical reinforcing plate on the outer peripheral surface of the middle pressed tube main body, providing an end plate on the front surface of the middle pressed tube main body, and between the reinforcing plate and the end plate on the outer peripheral surface of the middle pressed tube main body. Can be configured to integrate the reinforcing ring by welding.
[0013]
It is possible to adopt a configuration in which a washing water ejection hole is provided behind the above-mentioned seal groove, or a configuration in which a washing water ejection hole is provided behind the above-mentioned seal groove. Mud water from which earth and sand are separated can be used as the washing water ejected from the washing water ejection hole.
[0014]
A push ring provided with a seal portion between the outer peripheral surface of the end plate of the middle push tube main body and the inner peripheral surface of the middle push slide tube, a front end seal member attached to the seal portion, and detachably attached to the end plate. Against the front end seal member, and the middle push jack can be interposed between the press ring and the flange of the middle push slide tube.
[0015]
The pressing ring is constituted by a combination of a plurality of arc members, and the pressing ring is movably mounted in the axial direction with respect to the end plate, and the pressing ring is compressed during the compression of the front end sealing member accompanying the driving of the intermediate pressing jack. And the end plate can be brought into contact with each other.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0017]
1 to 3 is configured by a combination of a center-pushed tube main body 11 and a center-pushed slide tube 12, as in the conventional case. The centrally pressed tube main body 11 is made of concrete reinforced with a reinforcing cage, and is entirely covered with a cylindrical reinforcing plate 13 made of a formed steel plate except for a tip portion of an outer peripheral surface thereof. At one end, a receiving port 14 having a larger diameter is provided. Further, a reinforcing ring 15 made of a formed steel plate is integrally attached to a front end portion of the reinforcing plate 13 by welding, and a thicker annular end plate 18 is integrated with a front end of the reinforcing ring 15 by welding. The distal end portion of the middle pressed tube main body 11 is reinforced by the reinforcing ring 15 and the end plate 18.
[0018]
As shown in FIG. 2, the reinforcing ring 15 has one circumferential sealing groove 16 formed in the middle, and a reduced diameter portion 17 having the same diameter as the groove bottom of the sealing groove 16 at the rear end. Is formed. The reinforcing plate 13 is welded to the outer periphery of the reduced diameter portion 17. A seal member 19 is mounted on the seal groove 16 and is closely attached to the inner peripheral surface of the intermediately-pushed slide tube 12.
[0019]
Further, in a portion extending from the ridge 21 between the seal groove 16 and the reduced-diameter portion 17 to the reduced-diameter portion 17, the washing water ejection hole 22 penetrates through the reinforcing ring 15 and the reinforcing plate 13 and extends in the circumferential direction. They are provided at predetermined intervals. The washing water jet hole 22 is normally closed by a plug 30.
[0020]
Note that an inclined plate 20 is provided at a step between the receiving port 14 and the reinforcing plate 13 to make the step gradual.
[0021]
The middle-push slide tube 12 has a one-stage small-diameter insertion port 24 provided at the front end of a cylindrical fitting portion 23 formed of a formed steel plate as in the conventional case. An inward flange 25 is provided inside the step portion forming the outlet 24, and an inward flange 26 is provided at the tip of the outlet 24 so as to face the flange 25. Reinforcing concrete 27 is filled between both flanges 25 and 26. A seal member 37 is mounted on the outer peripheral surface of the above-mentioned outlet 24.
[0022]
The screw hole 28 provided on the front surface of the end plate 18 is necessary in the case of an embodiment using a pressing ring described later.
[0023]
The center push pipe of the first embodiment is as described above, and a required number of center push jacks 29 are interposed between the end plate 18 and the flange 25 at a required interval in the circumferential direction. The respective ends of the other standard propulsion pipes are inserted into the receiving port 14 at the rear end and the insertion port 24 at the front end, respectively, and the intermediate push pipe is interposed between these standard propulsion pipes.
[0024]
When propulsion is performed by the original push jack of the starting pit, the above-described middle push jack 29 is contracted, and the propulsive force of the original push jack is transmitted forward. When the middle push method is performed, the middle push jack 29 is driven with the standard push tube inserted into the receiving port 14 as the reaction force receiving side, and the push tube connected to the middle push slide tube 12 and the front thereof. To move forward.
[0025]
At this time, if necessary, pressurized water is spouted from the washing water spouting hole 22 to the outside through the gap S between the center-pushed pipe main body 11 and the center-pushed slide pipe 12, and the soil and the like clogged in the gap S are discharged to the outside. To reduce the slide resistance in the gap S. Mud water from which earth and sand have been removed can be used as the washing water in this case.
[0026]
Since the seal member 19 is mounted in the seal groove 16 of the reinforcing ring 15, the gap S between the center-pushed tube main body 11 and the center-pushed slide tube 12, as shown in FIG. It is determined by the height exposed from the groove 16. For example, when the nominal diameter is 1000 mm, the gap can be set as small as about 2 mm, whereby the pressure exerted on the seal member 19 and the like can be reduced, and a high water stopping power can be maintained.
[0027]
Next, a second embodiment will be described with reference to FIGS. In this case, in addition to the configuration of the first embodiment, the front end seal member 32 is attached to the seal portion 31 formed of the concave step provided on the outer peripheral surface of the end plate 18 and the front end seal member 32 is tightened. A pressing wheel 33 is provided.
[0028]
As shown in FIG. 5, the pressing wheel 33 is formed by combining three arc-shaped members into an annular shape, and is axially moved by a required number of bolts 43 screwed into the screw holes 28 of the end plate 18. Can be slid freely. The middle pressing jack 29 is interposed between the pressing wheel 33 and the collar 25 described above. Other configurations are the same as those of the first embodiment.
[0029]
In the above-described second embodiment, the front end sealing member 32 is compressed by tightening the pressing ring 33 with the bolt 34, and the front end sealing member 32 is pressed between the end plate 18 and the middle pressing slide tube 12 to perform strong sealing. be able to.
[0030]
When the middle push jack 29 is driven, the front end seal member 32 is strongly compressed by the reaction force, and a strong seal is performed (see FIG. 7). In this case, when the front end sealing member 32 is compressed to some extent, the interval between the pressing ring 33 and the end plate 18 is determined so that the front end sealing member 32 is not compressed more than necessary.
[0031]
The sealing by the front end seal member 32 and the pressing wheel 33 as described above may be performed from the beginning of the construction depending on the situation of the construction, or may be performed by the method of the first embodiment at the beginning of the construction, and the situation may be changed. Correspondingly, the method according to the second embodiment may be performed halfway. In this case, since the pressing wheel 33 is divided into three parts, it can be easily attached and detached.
[0032]
Next, in the third embodiment shown in FIG. 8, another sealing groove 16a is added to the reinforcing ring 15 of the first embodiment to provide two sealing grooves 16, 16a, and both sealing grooves 16 and 16a are provided. A water-stopping agent injection hole 35 is provided in a protruding portion between the grooves 16 and 16a. Seal members 19 and 19a are mounted in these seal grooves 16 and 16a. In addition, a closing plug 36 is fitted into the water blocking agent injection hole 35. The sealing strength is further increased by adding the sealing member 19a and injecting the water stopping agent. Other configurations are the same as those in the first embodiment.
[0033]
Next, in the fourth embodiment shown in FIG. 9, in addition to the above-described second embodiment, similarly to the case of the third embodiment, the reinforcing ring 15 is provided with two seal grooves 16 and 16a, A water blocking agent injection hole 35 is provided between them. In this case, there is an operational effect obtained by combining the second embodiment and the third embodiment.
[0034]
【The invention's effect】
As described above, according to the present invention, since the seal member mounted between the center-pushed tube main body and the center-pushed slide tube is mounted in the seal groove of the reinforcing ring, The gap with the push slide tube can be reduced, whereby the pressure acting on the seal portion from the outside can be reduced, and the water stopping power can be increased.
[0035]
Further, by forming the above-mentioned reinforcing ring by forming the middle push tube main body and the reinforcing ring by different members, a relatively thin material can be used as a material of the reinforcing ring. In this case, the decrease in strength due to the thin material is such that the seal groove itself acts as a reinforcing rib and compensates for this.
[0036]
Further, by providing the washing water jetting hole, the earth and the like clogged between the middle push tube main body and the middle push slide tube can be caused to flow out by washing water injection, thereby reducing the slide resistance.
[0037]
In addition, by using the front end seal member and the pressing ring for tightening the front end seal member, the water stopping power can be further increased.
[Brief description of the drawings]
1 is a sectional view of a first embodiment; FIG. 2 is a partially enlarged sectional view of the same; FIG. 3 is a partially enlarged sectional view of the same; FIG. 4 is a sectional view of a second embodiment; FIG. FIG. 6 is a partially enlarged sectional view of the same as above. FIG. 7 is a partial sectional view of the same during operation. FIG. 8 is a partial sectional view of a third embodiment. FIG. 10 is a sectional view of a conventional example. FIG. 11 is a partially enlarged sectional view of the embodiment.
DESCRIPTION OF SYMBOLS 11 Middle press pipe 12 Middle press slide pipe 13 Reinforcement plate 14 Receptacle 15 Reinforcement ring 16, 16 a Seal groove 17 Reduced diameter 18 End plate 19, 19 a Seal member 20 Inclined plate 21 Ridge 22 Wash water jetting hole 23 Fitting part 24 Insert Mouth 25, 26 Flange 27 Concrete 28 Screw hole 29 Middle push jack 30 Closure plug 31 Seal part 32 Front end seal member 33 Press ring 34 Bolt 35 Water blocking agent injection hole 36 Closure plug 37 Seal member

Claims (6)

A center-pressed slide tube is slidably fitted to the outside of the front end of the center-pushed tube main body in the center axis direction of the center-pushed tube main body, and an annular surface is fitted to the fitting surface of the center-pressed tube body and the center-pressed slide tube. A propulsion device which is provided with a sealing member between the front end of the center pressing tube main body and the flange of the center pressing slide tube , and is interposed between other propulsion tubes for use. In the construction middle push pipe, a reinforcing ring made of a formed steel plate having a circumferential seal groove is integrally provided on the outer peripheral surface of the front end portion of the middle push pipe main body, and the sealing member is attached to the seal groove. Characterized middle push pipe for propulsion method. Along with providing a cylindrical reinforcing plate on the outer peripheral surface of the middle pressed tube main body, providing an end plate on the front surface of the middle pressed tube main body, The middle push pipe for a propulsion method according to claim 1, wherein the reinforcing ring is welded and integrated. The middle push pipe for a propulsion method according to claim 1 or 2, wherein a washing water ejection hole is provided behind the seal groove. The center push pipe for a propulsion method according to any one of claims 1 to 3, wherein the seal groove is provided at two places, and a water blocking agent injection hole is provided between the two seal grooves. A push ring provided with a seal portion between the outer peripheral surface of the end plate of the middle push tube main body and the inner peripheral surface of the middle push slide tube, a front end seal member attached to the seal portion, and detachably attached to the end plate. 5. The propulsion method according to claim 2 , wherein the intermediate pressing jack is interposed between the pressing ring and a flange of the intermediate pressing slide pipe. 5. Push tube. The pressing ring is constituted by a combination of a plurality of arc members, and the pressing ring is movably mounted in the axial direction with respect to the end plate, and the pressing ring is compressed during the compression of the front end sealing member accompanying the driving of the intermediate pressing jack. 6. The push rod according to claim 5 , wherein the end plate is brought into contact with the end plate.

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