JP2801580B2 - Underground propulsion method and its device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground propulsion method for burying a pipe by press-fitting the pipe into the ground and burying the pipe.

[0002]

2. Description of the Related Art As a method of burying a pipe for laying a cable or the like in the ground, there is an underground propulsion method of a non-discharged press-fitting type which eliminates the need for residual soil treatment. As shown in FIG. 7, in this underground propulsion method, the starting shaft 1 and the reaching shaft 2 are first dug down to the level of the propulsion planning line B, the main pushing device 3 is installed in the starting shaft 1, and Is set in accordance with the promotion plan line B (a). Next, the main jack 4b provided on the leading conductor 4 is extended, and the tip head 4a is pressed into the ground (b). Then, the main jack 4b is contracted to attract the main body side of the leading conductor 4, and at the same time, the main pushing jack 3 of the main pushing device 3 is pulled.
a is extended and the propulsion tube 5 is pushed in (c). When the propulsion of one propulsion pipe 5 is completed by repeating the tip propulsion and the main push propulsion (double propulsion), a new propulsion pipe 5 is connected (d). When the connection between the predetermined number of the propulsion tubes 5 completes the propulsion between the shafts 1 and 2 and the leading conductor 4 enters the arrival shaft 2,
The leading conductor 4 is recovered (e).

In the underground propulsion system, a direction correcting jack is provided on the leading conductor 4, the propulsion pipe 5 is connected by a socket, and the position is detected with high accuracy by an electromagnetic method or the like. High-speed construction for long distance and curved propulsion was achieved.

[0004]

In recent years, it has become necessary to embed a steel pipe having a relatively large diameter, for example, 400 mm, as compared with the conventional one, in accordance with an increase in the amount of cables and the like laid. However, when the diameter is set to be large, the surrounding ground is fastened to the propulsion pipe, and the propulsion cannot be propelled because the original pushing thrust exceeds the limit (allowable stress of the propulsion pipe). That is, it becomes impossible to promote a long distance, which leads to an increase in the construction period and construction cost.

[0005]

[Summary of the present invention to solve the above problems, when propelling the propulsion tube to follow the lead body forming a guide hole for pipe burying, enlarged diameter portion on the lower side of the propulsion tube To
Attach, under the guide hole in the middle of the section where the propulsion pipe is propelled.
The side is expanded and propelled . Further, the main pushing thrust of the propulsion pipe is measured, and when the original pushing thrust exceeds a predetermined set value, the propulsion is continued after the enlarged diameter portion is attached to the newly added propulsion pipe. And cut in the middle to the propulsion pipe
Form a missing enlarged diameter part to form a lubrication passage, and
The sliding material may be propelled by flowing the sliding material from the sliding material passage to the side.
Propulsion in this manner can reduce the tightening of the ground with respect to the propulsion pipe and reduce the original thrust.

The present invention also relates to an underground propulsion device having a propulsion pipe for propelling a pipe burying hole formed by a leading conductor, wherein the diameter of the hole is appropriately increased at a part of the lower side of the propulsion pipe. In this case, an enlarged diameter portion is provided. Enlarged diameter portion is preferably one having a passage skids passing between the promotion pipe and the bore hole. Further, the enlarged diameter portion may be constituted by a linear member attached to the outer peripheral wall of the propulsion pipe. The linear member is preferably welded to a step of a socket for adding a propulsion pipe, and may be a reinforcing rod. Rebar bars
A deformed reinforcing bar having a rib formed on the outer peripheral surface may be used. With this configuration, the diameter of the guide hole can be increased during the propulsion of the propulsion pipe, and the tightening of the ground is eased.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 to 3 show an underground propulsion device according to the present invention. This underground propulsion device includes a propulsion pipe 12 for propelling a conduit 11 for burying a pipe formed by press-fitting a leading conductor (not shown).
2, an enlarged diameter portion 1 for appropriately expanding the diameter of the conductive hole 11
3 are provided. The propulsion pipe 12 is made of a steel pipe having a predetermined diameter φ, length L, and thickness t, and has a socket 14 formed at a base end (a rear end with respect to the propulsion direction F). That is, the distal end of the rear propulsion pipe 12 is inserted into the socket 14 so that the propulsion pipe 12 is successively added and buried in a predetermined propulsion section. The enlarged diameter portion 13 is formed by a reinforcing rod 15 which is a linear member attached along the outer periphery of the propulsion pipe 12. The propulsion pipe 12 is not limited to a steel pipe, but may be any pipe having a predetermined strength and rigidity, such as a fume pipe, a ductile steel pipe, and a hard vinyl pipe.

As shown in FIG. 2, the reinforcing rod 15 is provided on the lower half side of the propulsion pipe 12 in a ring shape with a middle cutout, and has a central angle from the left and right ends of the propulsion pipe 12 to the lower end. From 60 o'clock to α, from 3 o'clock to 5 o'clock
It is attached until the hour and between 7:00 and 9:00. That is, the section from 5:00 to 7:00 (the range of the central angle β) is formed as a sliding material passage 16 for passing the sliding material backward. The lubricating material is composed of a bentonite suspension, and is injected from the leading conductor toward the ground to form a propulsion pipe 12.
Flows rearward between the outer peripheral surface of the base member and the inner wall surface of the guide hole 11 to reduce its frictional resistance. In FIG. 2, the reinforcing rod 15 and the lubricating material passage 16 are arranged so that α = β, but the arrangement can of course be set arbitrarily. However, reinforcing bars 15
Is continuously provided over the entire circumference of the propulsion pipe 12, since the flow of the lubricating material is hindered and the weight of the propulsion pipe 12 is increased. Therefore, it is desirable to attach the propulsion pipe 12 to a minimum necessary length. In this case, the propulsion pipe 12 has its own weight, so that
, The lower side tends to approach. Therefore, by providing only the lower side as shown, overcut can be effectively performed.

The diameter d of the reinforcing rod 15 is set so that the distance between the outer peripheral ends of the reinforcing rod 15 (maximum outer diameter D) does not become larger than the outer diameter of the leading conductor. For example, when the diameter φ of the propulsion pipe 12 is 40
If 0 mm and the outer diameter of the tip of the leading conductor is 430 mm, D = 418
So that the appropriate overcut amount of about 425mm
Use the one with d = 9mm. Also, as the reinforcing bar 15,
A monotonous round bar having a circular cross section may be used, or a deformed reinforcing bar 18 having a rib 17 formed on the outer peripheral surface as shown in FIG. 4 may be used. Since the deformed reinforcing bar 18 has a slight gap s between itself and the hole wall 11a, it does not excessively hinder the passage of the sliding material. It is not necessary to provide the reinforcing rod 15 on each propulsion pipe 12, and if the length L of one propulsion pipe 12 is 2.5 m,
For example, it is desirable to attach the socket 14 at the position of the socket 14 at a ratio of one out of 16 (propulsion interval of 40 m).

As shown in FIG. 3, the socket 14 is formed by superimposing a short pipe 19 having an outer diameter larger by the thickness t on the base end of the propulsion pipe body 12a. And at the base end of the propulsion pipe main body 12a, which are fixed by Sumi welding 20, 21, respectively. And reinforcing bar 1
Reference numeral 5 denotes a position of a front end side of the short weld 16 serving as a stepped portion, which is applied to the front end surface 19a of the short pipe 19. It is attached to the end by welding 22, 23, respectively.
In particular, the welding 22 on the front side prevents the earth and sand from entering between the reinforcing rod 15 and the propulsion pipe main body 12a, thereby smoothing the diameter of the guide hole 11.

In addition, as shown in FIG. 5, as a device for propelling the propulsion tube 12, a main pressing device 25 having a main pressing jack 24 for pushing the propulsion tube 12, a main pressing jack 24 and a leading conductor A power unit (hydraulic unit) 26 for supplying drive hydraulic pressure to the jacks (a main jack for press-fitting and a direction correcting jack), and an operation panel 27 for appropriately driving the power unit 26 are provided. The operation panel 27 receives propulsion data from various sensors, such as a position detection system that detects the position of the leading conductor by an electromagnetic method or the like. It provides monitoring and operation support for proper propulsion control.

Next, an embodiment of the underground propulsion method of the present invention will be described as an operation when propulsion is performed by the underground propulsion device. First, the main pushing device 25 is installed on the starting shaft 1,
The leading conductor is set to the propulsion plan line B, the main jack is extended, and the tip head is pressed into the soil. At the same time as the main jack is contracted, the original pushing jack 24 is extended and the propulsion pipe 12 is pushed in. When the propulsion of one propulsion tube 12 is completed by the repetition of the tip propulsion and the main push propulsion, a new propulsion tube 12 is connected with the socket 14. In parallel with this propulsion, the fluctuation of the original pushing thrust displayed on the operation panel 27 is monitored. If the original pushing thrust shows a sudden rise or exceeds the set value, the reinforcing rod 15 is attached to the step portion of the socket 14 of the propulsion pipe 12 to be newly added.
The rebar rod 15 is heated and curved in an arc shape along the outer periphery of the propulsion pipe 12, then cut to a predetermined length, and continuously or intermittently over its entire length. Weld over the short pipe 19. The propulsion tube 12 with the reinforcing rod is added to continue the propulsion. This is the bar 1
5, as shown in FIG. 3, expands the diameter of the guide hole 11 reduced in diameter by tightening the ground (ground pressure), and reduces the frictional force acting between the propulsion pipe 12 and the guide hole 11. . When the frictional force is reduced, the propulsion pipe 12 is smoothly propelled. When the propulsion in the predetermined section is completed and the leading conductor enters the reaching shaft, the propulsion pipe 12 is recovered.

FIG. 6 shows the relationship between the original pushing thrust and the propulsion length in a propulsion experiment conducted by the present inventors. The stratum to be propelled at this time is the Kanto loam stratum with an N value of about 10, but such a relatively hard ground has a relatively large diameter (φ
= 400mm), the conventional underground propulsion method using only the propulsion pipe 12 without the reinforcing rod 15
At about 100 m, the limit of propulsion is reached, and long-distance propulsion becomes impossible (a).

On the other hand, as shown in FIG. 6 (b), in the case of the present invention, the edge thrust (the original thrust at the start of the day) and the original thrust during the continuous operation are continuously measured and monitored. At the time when the original pushing thrust has risen to nearly half of the limit thrust (propulsion position of about 40 m, indicated by a ★ mark in the figure), the reinforcing rod 15 was attached to the newly added propulsion pipe 12. . When the propulsion tube 12 with the reinforcing rod was connected and the propulsion was continued, no increase in the main thrust was observed for a while, and the thrust still had a margin at the time of propulsion at 100 m. That is, the original pushing thrust is much smaller than that of the conventional propulsion method, and the regression line C ₁ showing the tendency of the change is represented by a straight line.
Judging from the above, the length that can be propelled was determined to be about 260 m, which was much longer than the conventional propulsion length. Next, FIG.
In the case shown in (c), a reinforcing rod 15 was attached to the propulsion pipe 12 about every 40 m, and the propulsion was performed to about 150 m. That is, as shown by the ★ marks in the figure, the diameter was expanded at three places in the propulsion section. As a result, further elongation promotion possible lengths, promoting length of about 290m to determine the regression line C ₂ is obtained. In the case shown in FIG.
At the time of 70m propulsion (★ mark in the figure), a reinforcing rod 1
5 When a mounted, the casing and than it increases the proportion of the original pushed by force is somewhat larger, as the propulsion possible length, judging from the regression line C _3, much than that of a conventional jacking method About 190m long was obtained.

As described above, the enlarged diameter portion 1 is formed in a part of the propulsion pipe 12.
3 is provided so that the diameter of the conducting hole 11 is appropriately increased.
Tightening of the ground to the propulsion pipe 12 can be reduced, the excessive increase of the original thrust can be suppressed, and the propulsion can be continued with a small original thrust. In other words, even in the case of propulsion of a relatively large bore having a large frictional resistance, rapid long-distance propulsion is achieved, and an increase in construction costs can be prevented. Further, since the original pushing thrust does not excessively increase, countermeasures for propulsion reaction force such as reinforcement of the rear member in the starting shaft 1 are reduced, and push-up or the like is not required, thereby improving workability. Also, the enlarged diameter portion 13
Is provided on the lower side of the propulsion pipe 12, even if the amount of protrusion of the enlarged diameter portion 13 is small, it is possible to effectively overcut the necessary amount. Further, since the passage 16 for the sliding material is provided in the enlarged diameter portion 13, the sliding material can be applied to the entire propulsion section without obstructing the flow of the sliding material. In addition, enlarged diameter part 1
Since the reinforcing bar 15 is attached to the outer periphery of the propulsion pipe 12 as 3, the attachment position can be set arbitrarily and can be easily attached. Since the reinforcing rod 15 is welded to the step portion in front of the socket 14, the reinforcing rod 15 can be provided at the end face of the short pipe 19, and the mounting strength with respect to the diameter expansion resistance can be secured.

It is desirable to determine the mounting position (mounting interval) of the reinforcing rod 15 while measuring and managing the original pushing thrust. However, the measuring management is omitted, and the reinforcing rod 15 is mounted at a preset interval. It may be. However, the diameter of the propulsion pipe 12 and the soil to be propelled (cohesive soil / sandy soil,
It should be noted that the optimum mounting interval is expected to greatly change depending on conditions such as N value) . As an attaching its the outer periphery of the propulsion tube 12 is not limited to reinforcing steel bar 15, it may be a filament member having a comparable strength. The cross-sectional shape of the linear member is not limited to a circle, but may be, for example, an ellipse or a rectangle. Further, the enlarged diameter portion 13 is not limited to be formed of a linear member. For example, a part of the propulsion pipe main body 12a may be formed to have a large thickness to be an enlarged diameter portion .

[0018]

In summary, according to the present invention, it is possible to reduce the tightening of the ground to the propulsion pipe, suppress an excessive rise in thrust, and achieve long-distance propulsion with a relatively large diameter. It has the effect.

[Brief description of the drawings]

FIG. 1 is a plan sectional view of an underground propulsion device showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an enlarged view of a main part of FIG. 1;

FIG. 4 is a partial cross-sectional view showing another embodiment of FIG.

FIG. 5 is a side view showing an apparatus for propelling the propulsion pipe of FIG. 1;

FIG. 6 is a diagram illustrating the relationship between the original pushing thrust and the propulsion length for explaining the operation and effect of FIG. 1;

FIG. 7 is a side sectional view for explaining a basic process of the underground propulsion method.

[Explanation of symbols]

 4 Lead Conductor 11 Guide Hole 12 Propulsion Tube 13 Larger Diameter Portion 14 Socket 15 Reinforcing Bar (Straight Member) 16 Passage of Slipper 18 Deformed Rebar Bar 25 Main Pushing Device

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Susumu Hasegawa 2-3-9 Higashi-Shimbashi, Minato-ku, Tokyo Inside Todentsu Co., Ltd. (56) References JP-A-6-42290 (JP, A) JP-A-6 -146785 (JP, A) JP-A-9-195675 (JP, A) Utility model registration 2521303 (JP, Y2) (58) Fields investigated (Int. Cl. ⁶ , DB name) E21D 9/06 311

Claims (9)

(57) [Claims] When a propulsion pipe is propelled by following a leading conductor forming a conduit for burying a pipe, the lower side of the propulsion pipe is provided.
An underground propulsion method characterized in that a diameter-enlarging portion is mounted on the underwater hole , and the underside of the above-mentioned guide hole is expanded and propelled in the middle of the section where the propulsion pipe is propelled. 2. A measuring original pushed by force of the upper Symbol propulsion tube, when it exceeds a value said original pushed by force is set, after attaching the enlarged diameter portion to the propulsion tube a new annex to continue to promote Claim 1
Underground propulsion method described . 3. An enlarged diameter portion cut in the middle of the propulsion pipe.
To form a lubrication passage, and the lubrication passage
3. The method according to claim 1, wherein the lubricating material flows from the material passage and is propelled.
Underground propulsion method described above. 4. A guide hole for burying a pipe formed by a leading conductor.
Underground propulsion device with a propulsion tube
To appropriately expand the diameter of the above-mentioned guide hole in the lower part of the propulsion pipe
An underground propulsion device comprising an enlarged diameter portion . 5. The underground propulsion device according to claim 4 , wherein the enlarged diameter portion has a passage for a sliding material passing between the propulsion pipe and the guide hole. 6. The underground propulsion device according to claim 4 , wherein the enlarged diameter portion is a linear member attached to an outer periphery of the propulsion pipe. 7. The linear member is welded to a step of a socket for adding the propulsion tube.
An underground propulsion device according to item 1. 8. The wire member according to claim 6, wherein the linear member is a reinforcing rod.
Or the underground propulsion device according to 7. 9. The underground propulsion device according to claim 8, wherein the reinforcing bar is a deformed reinforcing bar having a rib formed on an outer peripheral surface.