JPH0579283A - Propulsion pipe - Google Patents

Abstract

PURPOSE:To correctly set a pipe suitable for sewer which effectively prevents the sedimentation, piling, etc., of dirt and solid articles by carrying out propulsion by a circular excavating means which is generally used and set the pipe at a prescribed attitude, without requiring the work such as baak-filling work which incurs the increase of the execution manhour. CONSTITUTION:The sectional shape of the inner periphery 2 of a propulsion pipe 1 is formed to an oval shape, and the sectional shape of the outer periphery 3 is formed to a circular shape. On the outer peripheral surface, projections 4,... which project outwardly are formed continuously or intermittently in the pipe axis direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propulsion pipe, that is, a pipe buried in the ground by a propulsion method.

[0002]

2. Description of the Related Art For example, as a sewage pipe buried in the ground, conventionally, as shown in Japanese Utility Model Publication No. 52-43181, the cross section of the inner circumference is formed in an oval shape and the outer circumference is formed. There is known a tube having a circular cross section and a so-called oval tube having an inner cross section and an outer cross section each having an oval shape (see Japanese Patent Application Laid-Open No. 1-210595). According to this type of pipe, the water depth at low speed is deeper than that of a circular pipe, and the flow velocity is also increased by that amount, so it is possible to prevent sedimentation and accumulation of dirt and solids.

On the other hand, since it is necessary to reduce the amount of excavated soil and the excavated area when burying a pipe, in recent years, a propulsion method has been adopted in which a pipe is press-fitted from a vertical shaft using an excavator or the like or the pipe is inserted after excavation. Often. However, in the case of an oval tube, since the cross-sectional shape of the outer circumference is not a circle but a special shape of an oval shape, it is difficult to use a normal excavator having a circular excavation cross section.

Therefore, in the propulsion machine of the above-mentioned Japanese Patent Laid-Open No. 1-210595, the excavator body is composed of the large-diameter-side excavation means and the small-diameter-side excavation means for excavating the large-diameter portion and the small-diameter portion of the oval cross section, respectively. The two excavating means simultaneously excavate other gaps so that the excavated cross section has an oval shape, and then the oval tube is pushed in to promote the excavation.

[0005]

However, according to the technique using the excavator as described above, two excavating means, large and small, must be provided for excavating in an oval cross section, and the excavator has a complicated structure. become. In other words, there is a problem that the tube can be propelled only by using a propulsion machine dedicated to the oval tube, which is more complicated than a normal excavator. In addition, when the unsanded portion of the earth and sand in the gap between the two large and small excavating means is left unetched, the pressure of the earth and sand may directly act on the pipe to destroy the pipe body.

It should be noted that excavation is performed in a circular cross-sectional shape having the major axis of the oval tube as a diameter, and a slurry material containing a solidifying material is injected (so-called backfilling) into the gap between the oval tube and the excavation hole. Although there is a technique, in that case, it is unavoidable that the construction man-hours increase by the amount of injection of sludge material, and further, for example, if the solidifying material is uncured after the propulsion, the oval tube may collapse and not be set correctly. is there.

The present invention has been made in view of the above points, and is a generally used circular pipe as a pipe suitable for a sewer pipe or the like which can effectively prevent sedimentation and accumulation of dirt and solids. An object of the present invention is to provide a propulsion pipe that can be propelled by an excavation means, does not require work such as backfilling that causes an increase in construction man-hours, and can be correctly set in a predetermined posture. ..

[0008]

To achieve the above object, the present invention is configured as follows in a propulsion pipe which is continuously propelled by a leading conductor of an excavator and is buried in the ground. That is, the cross-sectional shape of the inner circumference is formed in an oval shape, while the cross-sectional shape of the outer circumference is formed in a circle, and projections projecting outward are continuously or intermittently arranged on the outer circumferential surface in the pipe axis direction.

Here, the oval shape which is the inner peripheral cross-sectional shape of the propulsion pipe may be smaller than the oval shape which is inscribed in the circular shape which is the outer peripheral cross-sectional shape, but has the smallest wall thickness after the propulsion pipe is buried. Even if the surrounding earth pressure acts on the part (the part corresponding to the long axis direction of the oval shape), it is necessary to secure a wall thickness that can withstand this. This wall thickness may be determined according to the buried depth of the propulsion pipe.

When the receiving end or the spigot is provided at the end of the propulsion pipe, its cross-sectional shape may be circular corresponding to the outer peripheral shape of the propulsion pipe or oval corresponding to the inner peripheral shape. May be Furthermore, since the thickness of the portion corresponding to the minor axis of the egg shape becomes thicker, there is no problem even if the portion is arbitrarily deformed within the range permitted by this portion. However, if the pipes rotate around the pipe axis during propulsion and a circumferential displacement occurs, the egg shape, which is the inner peripheral cross-sectional shape, will not match at the pipe connection part. The outer peripheral cross-sectional shape of the portion is also preferably an oval or other irregular cross-section.

Regarding the above-mentioned arrangement of the inlet and the outlet, it is general to provide the inlet at one end of the propulsion pipe and the inlet at the other end, but to provide the outlet at both ends. Even if a propulsion pipe or a propulsion pipe with a spigot at both ends can be used by connecting them alternately, it may be configured to have either a socket or a spigot at both ends. It is possible.
Furthermore, it is also possible to connect by using a dedicated collar having a corresponding socket or outlet.

Therefore, the arrangement of the receiving port or the spout is arbitrary, but considering the convenience of construction, when the pipes are directly connected, the receiving port is formed at one end and the spout is formed at the other end. When connecting through a collar, it is preferable to unify both ends of the propulsion pipe into one of the receiving port and the receiving port, and correspondingly, unify both ends of the collar with either the receiving port or the receiving port. still,
If the inner diameter of the collar receiving port is matched with the outer diameter of the propelling tube, it is not necessary to provide a receiving port or a spigot at the tube end of the propelling tube.

Examples of the material for the propulsion pipe include general-purpose thermoplastic resins such as polyvinyl chloride and polyethylene, fiber reinforced resin (FRP), and glass fiber reinforced thermosetting resin (for example, glass fiber reinforced if necessary). Polyester / glass fiber laminate) and the like. Since the projection on the outer peripheral surface of the propulsion pipe is provided to prevent rotation of the propulsion pipe around the axis, the dimension from the tip to the outer peripheral portion (pipe bottom portion) on the opposite side (substantially the maximum effective dimension) ) Must be larger than the diameter of the drill hole made by the conductor.
In other words, it is necessary that the sum of the length from the base end to the tip of the protrusion and the diameter of the propulsion pipe is larger than the cross-sectional diameter of the drill hole.

At least one projection is sufficient, but a plurality of projections may be provided if necessary. However, as the number of protrusions increases, the propulsion resistance increases accordingly.
One degree is preferable. Further, the protrusion direction of the protrusions is arbitrary, and may be, for example, a radial direction with respect to the tube axis, or may be a direction in which the protrusions are arranged in parallel to each other.

Furthermore, the longitudinal arrangement of the projections, that is, the arrangement along the pipe axis direction may be continuous or intermittent, but when the projection is propelled in the pipe axis direction, it may be ground. In order to reduce the influence of the shearing force received from the above, it is preferable to adopt a configuration in which it continuously extends as shown in Examples described later. In using the propulsion pipe of the present invention, excavation, earth removal, etc. can be performed by a known propulsion method.
There is no problem even if the construction sequence is the same as the conventional one.

[0016]

According to the propulsion pipe having the above structure, the cross-sectional shape of the outer circumference is circular. Therefore, by making the diameter of the circle correspond to the diameter of the excavator forward conductor, the cross section of the excavation hole to be excavated by the forward conductor. It is possible to substantially eliminate the difference in shape and size between the section and the cross section of the propulsion tube (the section in the direction orthogonal to the tube axis). Therefore, the resistance acting on the propulsion pipe at the time of propulsion is reduced, and the load on the propulsion pipe is reduced accordingly. Therefore, it is possible to avoid an increase in construction man-hours.

Further, since the outer peripheral surface has a circular cross-sectional shape, it becomes possible to propel the propulsion pipe by various circular excavation means generally used in the conventional propulsion method. Furthermore, since the cross-sectional shape of the inner circumference is oval, it can exhibit the same function as that of a conventional oval tube, that is, the function of effectively preventing precipitation or accumulation of dirt or solid matter.

Moreover, the projection in the axial direction of the pipe arranged on the outer peripheral surface is press-fitted into the surrounding ground, so that the propulsion pipe is fixed so as not to rotate in the circumferential direction. As a result, the propulsion tube is set in a predetermined posture so that the oval shape of the inner peripheral surface faces the correct direction.

[0019]

EXAMPLES Examples of the present invention will be described below. 1 and 2 show a first embodiment of the present invention. As shown in the figure, in the propulsion pipe 1 according to this embodiment, an inner circumference 2 has an oval cross section and an outer circumference 3 has a circular cross section. The circular size, that is, the diameter, is set to be substantially the same as the diameter of the tip conductor (not shown) of the excavator used to propel the propulsion pipe 1. It should be noted that neither the receiving port nor the spout is provided at both ends of the propulsion pipe 1 in this embodiment.

A plurality (six in the illustrated example) of plate-like projections 4 ... These protrusions 4 ... 4 are respectively
It is projected in a direction parallel to the long axis of the oval (vertical direction in FIG. 2), and in the protruding state, it is in the tube axial direction (FIG. 1).
In the left-right direction). Then, when the propulsion pipe 1 is propelled following the leading conductor that advances while excavating the ground, the protrusions 4 ... 4 are press-fitted into the surrounding ground to rotate the propulsion pipe 1 around the pipe axis. It is designed to prevent

In the propulsion tube 1 thus constructed, the outer periphery 3 has a circular cross-sectional shape and the diameter of the circle is set to be substantially the same as the diameter of the excavator tip conductor. Cross section of excavated hole and propulsion pipe 1
There is no difference in terms of shape and size between the section and the section (section perpendicular to the tube axis). Therefore, the resistance acting on the propulsion pipe 1 during propulsion is reduced, and the load on the propulsion pipe 1 is reduced accordingly.

Further, since there is no gap between the propulsion pipe 1 and the above-mentioned excavation hole, which requires backfilling, backfilling work becomes unnecessary. As a result, it is possible to avoid an increase in construction man-hours. Further, as a result of the outer peripheral surface 3 having a circular cross-sectional shape, the propulsion tube 1 can be propelled by various circular excavation means that have been generally used in the propulsion method. It is not necessary to use the digging means of.

On the other hand, since the cross-sectional shape of the inner circumference 2 is oval like the conventional oval tube, the function peculiar to this kind of tube, that is, the precipitation and accumulation of dirt and solids is prevented. The obtained function can be fully exerted. Further, at the time of propulsion, the plate-shaped projections 4 ... 4 which are arranged on the outer peripheral surface and extend in the tube axis direction are press-fitted into the surrounding ground so that the propulsion tube 1 does not rotate in the circumferential direction. Since it is fixed, the propulsion tube 1 is set in a predetermined posture so that the oval shape of the inner peripheral section faces the correct direction.

In the above embodiment, neither the receiving port nor the spigot is provided at both ends of the propulsion pipe 1, but unlike the second embodiment shown in FIG. 3 and FIG. The outlet 11a may be formed at one end and the receiving port 11b may be formed at the other end. In that case, as shown in FIG.
Also, each outer peripheral cross-sectional shape of the receiving port 11b may be formed in a circular shape, or like the propulsion pipe 21 of the third embodiment shown in FIGS. 5 and 6, both outer peripheral cross-sectional shapes of the outlet 21a and the receiving port 21b. May be formed into an oval shape together. Also in these second and third embodiments, predetermined projections 14 ... 14 and 24 ... 24 are provided on the outer circumferences of the propulsion pipes 11 and 21.

Regarding the projections on the outer peripheral surface of the propulsion tube, the projections 34 ... 34 may be radially projected as seen from the tube axis direction like the propulsion tube 31 shown in FIG.

[0026]

As described above, according to the present invention, since the outer peripheral cross-sectional shape of the propulsion pipe can be matched with the shape of the leading conductor at the tip of the excavator, almost all tip resistance directly received from excavated soil during propulsion is excavated. It is possible to place a burden on the tip conductor, and as a result, it is possible to reduce the burden on the propulsion pipe during propulsion. This makes it possible to reduce the risk of breakage of the propulsion pipe during propulsion.

Further, since there is no gap between the cross section of the excavation hole and the propulsion pipe, it is not necessary to carry out backfilling, and the number of construction steps can be reduced accordingly. Further, since the conventional general excavation means having a circular cross section can be used, it is not necessary to specifically use the excavation means dedicated to the oval tube having a complicated structure. Moreover, since the protrusions on the outer peripheral surface of the propulsion pipe are pressed into the surrounding ground, the propulsion pipe is fixed so as not to rotate in the circumferential direction, so that the oval shape of the inner peripheral cross section is oriented in the correct direction. The propulsion pipe will be set in.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a propulsion pipe showing a first embodiment of the present invention.

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

FIG. 3 is a partially cutaway front view of a propulsion pipe showing a second embodiment of the present invention.

4 is a cross-sectional view taken along the line BB of FIG.

FIG. 5 is a partially cutaway front view of a propulsion pipe showing a third embodiment of the present invention.

6 is a cross-sectional view taken along the line CC of FIG.

FIG. 7 is a sectional view of a propulsion pipe according to a fourth embodiment of the present invention as seen from the axial direction.

[Explanation of symbols]

 1, 11, 21, 31 ... Propulsion tube, 2 ... Inner circumference, 3 ... Outer circumference, 4, 14, 24, 34 ... Projection.

Claims (1)

[Claims] 1. In a propulsion pipe which is continuously propelled by a leading conductor of an excavator and is buried in the ground, an inner peripheral cross-sectional shape is formed in an oval shape, and an outer peripheral cross-sectional shape is formed in a circular shape, and an outer circumference is formed. A propulsion pipe characterized in that projections protruding outward are continuously or intermittently arranged in the axial direction of the pipe.