JPH0721280B2 - Non-removal soil promotion method for buried pipes - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-removing earth propulsion method for buried pipes, and more specifically, when constructing underground buried pipes for sewers, etc., excavating a buried hole in the ground without excavating the ground. This is related to a so-called no-soil promotion method in which buried pipes are sequentially pushed into the formed burial holes while being formed and buried, and the excavated earth and sand are treated in the ground without being discharged to the outside. .

[0002]

2. Description of the Related Art As a method for provoking underground buried pipes, an excavator equipped with an excavating mechanism such as an auger at the tip is used to excavate a buried hole in the ground while the excavator excavates and drives the buried pipe. There is a method of doing this, and this construction method is generally called the auger construction method. In the auger method,
The earth and sand excavated by the excavator is conveyed rearward through the interior of the buried pipe row for propulsion and buried, and is transported from the rear end of the buried pipe row to the vertical shaft or the surface and disposed of. However, with this method, it is necessary to install a soil transfer mechanism inside the narrow burial hole from the excavator to the rear end of the burial pipe line, which complicates the equipment and increases the equipment cost and operating cost. Also, the propulsion speed of the excavator has to be set according to the transfer capacity of the excavated soil, the propulsion speed cannot be too fast, and it takes time and cost to dispose the excavated earth and sand as waste. was there.

Therefore, in the case of a buried pipe having a relatively small diameter, a non-discharging type propulsion method is employed in which excavated earth and sand are treated inside the embedding hole and the soil is not discharged to the outside. Specifically, a conical or the like conductor is press-fitted into the ground to form a buried hole. The earth and sand removed from the outer circumference by the conductor
Since the inner wall of the embedding hole, that is, the ground side, is compacted, the embedding hole can be formed without discharging the soil to the outside. As a concrete no-ejecting method, an impact press-fitting method using compressed air or a press-fitting method using a hydraulic jack is adopted. However, in these non-removal earthing methods, there is a great resistance to press-fit the lead conductor into the ground, and it is necessary to apply an extremely large propulsive force to the lead conductor. Therefore, there is a problem that equipment such as a source push jack that gives a propulsion force becomes large in size and power required for operation increases.

As a non-removing earth method for solving the above problems, the following method has been proposed. The construction method is that the tip of the tip conductor is provided with an excavation mechanism like the auger construction method, and the tip conductor, that is, the excavator, excavates the ground in front of the excavator to bury a hole corresponding to the outer diameter of the excavator. Form, and once the excavated earth and sand are taken into the excavator,
The earth and sand taken in is pushed out in the radial direction at the rear of the excavator from a soil discharge port that opens on the outer peripheral surface of the excavator, and is compacted from the inner wall of the buried hole to the ground side. In this method, since the ground is excavated by an excavator and then the ground is compacted on the outer circumference, the resistance in the axial direction is small compared to the case where the pre-conductor is forcedly pressed into the ground. It is possible to do. Further, in the above construction method, a cone-shaped cone rotor that eccentrically rotates is provided inside the excavator, and the earth and sand are pushed out radially from the soil discharge outlet by the radial force associated with the eccentric rotation of the cone rotor. Therefore, a method for efficiently consolidating the soil to the ground side has also been proposed.

According to the above-mentioned improved soil-free construction method, it is said that the propulsion and burying construction of the burial pipe can be carried out efficiently at a lower cost.

[0006]

However, even with the above-mentioned improved soil-free earthing method, as the diameter of the buried pipe becomes larger, it becomes more difficult to drive the excavator and the buried pipe row, and the buried pipe having a large diameter can be obtained. Is not applicable. In other words, in the non-removing earth method, the excavation diameter of the ground excavated by the excavator increases as the diameter of the buried pipe increases, and a large amount of earth and sand corresponding to the large excavation diameter is compacted on the ground around the excavator. However, if the amount of soil compaction increases, the resistance at the time of propulsion increases, and a large propulsion force is required. Will not be possible, and promotion will be impossible.

The above problem will be described in detail. As shown in FIG. 4, when embedding a buried pipe having an outer diameter D, the cross-sectional area πD ² /
Sediment in the range of 4 must be completely compacted and discharged to the ground side. From the soil condition of the ground and the lateral compression capacity of the excavator, in the cross section of the ground, if the inner wall of the burial hole can be compressed and expanded to the outer peripheral side, that is, the consolidating depth is t, then π (D + 2t ^{) 2/4-πD 2/} 4 is capable of forming voids by lateral compression, i.e. becomes the cross-sectional area of the space for accommodating the soil, sediment range corresponding to the outer径断area of buried pipe in the cross-sectional area Will have to be excavated. In this case, assuming the volume reduction rate due compaction drilling soil and alpha, the sediment range corresponding to the cross-sectional area of the ^{(1-α) πD 2/} 4, fully incorporated into the void cross-sectional area described above There must be. for that reason,
The inner diameter of the embedding hole, that is, the outer diameter D of the embedding pipe for propulsion embedding is limited by the following formula.

[0008] ^{(1-α) πD 2/} 4 ≦ π (D + 2t) 2/4-πD 2/4 That is, D ≦ {2 / [(2-α) ^0.5 -1]} t In other words, no dumping The outer diameter D of the buried pipe that can be propelled is
When the lateral compression depth is t and the volume reduction rate due to consolidation of excavated soil is α, {2 / [(2-α) ^0.5 -1]} t
Up to.

For example, when t = 5 cm and α = 0.1 (10%), which are the general conditions in the conventional non-burning earth propulsion method, a non-burning earth is required for a buried pipe with an outer diameter D = 26.4 cm. It is possible to propel it, but it means that it is impossible to propel soil-free with a buried pipe having an outer diameter larger than that. Even if t = 5 cm and α = 0.15 are achieved by increasing the compaction capacity by using the eccentric rotating cone rotor, it is applicable only to the buried pipe from the previous formula to D = 44.6 cm. Can not. In other words, the amount of excavated soil is large, the cost of its transportation and disposal occupies a large proportion of the total construction cost, and it is considered that the advantages of the non-removal method are large. The soil propulsion method cannot be applied.

Therefore, an object of the present invention is to eliminate the above-mentioned problems relating to the limit of the applicable pipe diameter in the conventional soil-free construction method, and to eliminate the use of a buried pipe which can be favorably applied to medium and large diameter pipes. It is to provide earthwork method.

[0011]

In order to solve the above-mentioned problems, a buried pipe free earth propulsion method according to the present invention is to excavate the ground at the tip of an excavator for propelling in the ground and to excavate the excavated earth and sand. In the earth-free propulsion method for buried pipes, which is taken into the machine, the soil that has been taken in is compacted and discharged to the ground side on the outer periphery of the machine, and the buried pipe is propulsively buried in the buried hole formed behind the machine. An excavator equipped with a large-diameter tip with a larger outer diameter than the buried pipe and a rear part with an outer diameter almost the same as the buried pipe, excavates the ground with a larger excavation diameter than the outer diameter of the buried pipe, and excavates. At least a part of the earth and sand taken into the machine is discharged to the outer periphery of the excavator at a position rearward of the large-diameter tip of the machine.

As the basic structure of the excavator, the same structure as the above-mentioned conventional discharge-free propulsion method involving excavation of the ground is used. An excavation mechanism including a bit for excavating the ground or an excavation blade is provided at the tip of the excavator. A driving mechanism such as an electric motor or a hydraulic / pneumatic motor is attached to the excavation mechanism. The excavation diameter of the excavation mechanism is set to be substantially the same as or smaller than the outer diameter of the large-diameter tip portion forming the front portion of the excavator. The outer diameter of the large diameter portion at the tip of the excavator and the excavation diameter of the excavation mechanism are set to be larger than the outer diameter of the buried pipe to be propulsively buried. The outer diameter and the excavation diameter of the large-diameter portion at the tip are determined by the soil conditions of the ground, the compaction capacity of the excavator, or the construction conditions such as the outer diameter of the buried pipe. The earth and sand excavated from the ground by the excavation mechanism is taken inside the excavator and sent to the rear.

The rear portion of the excavator has a smaller outer diameter than the large-diameter portion at the tip and has an outer diameter substantially the same as the outer diameter of the buried pipe. Has a step. The buried pipes are sequentially connected to the rear part of the excavator, and the buried pipes are propulsively buried along with the promotion of the excavator. The earth and sand excavated by the excavation mechanism and sent to the rear of the excavator,
It is discharged to the outer periphery of the excavator at a position rearward of the large diameter tip. That is, in the vertical wall portion of the step caused by the difference in outer diameter between the large-diameter tip portion and the rear portion of the excavator, an axial soil outlet opening rearward in the axial direction of the excavator, or
From the rear soil discharge port that opens to the outer periphery of the rear part of the excavator,
The earth and sand are being discharged. The axial outlet is
In addition to being oriented in exactly the same direction as the axial direction of the excavator, it may be inclined outward and inclined with respect to the axial direction. The rear soil discharge port may be oriented in the radial direction of the excavator or may be inclined obliquely rearward. The axial and rear soil discharge ports may be formed in a continuous annular shape over the entire circumference of the excavator, or a plurality of soil discharge ports divided at intervals in the circumferential direction may be arranged. Incidentally, in the excavator, as in the case of the conventional excavator, the outermost peripheral soil discharge port that is opened in the radial direction on the outer peripheral surface of the tip large diameter portion that is the outermost periphery of the machine is the axial soil discharge port. It can also be installed along with the rear soil discharge port.

The earth and sand discharged at a position rearward of the large diameter portion of the excavator is compacted on the ground side to form an inner wall of the burial hole, and the burial pipe is propelled into the burial hole. An eccentrically rotating cone rotor can be provided in the earth and sand passage portion inside the excavator. The cone rotor has a substantially conical shape with a sharp tip located on the rear side of the excavation mechanism, and the rear outer peripheral tip is arranged near the soil discharge port. The cone rotor is rotated by a drive mechanism such as a motor as in the excavation mechanism, and the central axis of the cone rotor is attached so as to be slightly eccentric with respect to the rotation axis of the drive mechanism. When the cone rotor rotates eccentrically, the earth and sand can be discharged to the rear outer peripheral side along the conical outer shape of the cone rotor while stirring and crushing the earth and sand, and applying strong pressure from the earth discharging port to the ground side. That is, the cone rotor has an excellent compaction effect. The outer wall structure of the cone rotor is made of a material such as earth and sand or pebbles that can withstand impact, and can be provided with projections and uneven shapes for crushing pebbles and the like.

Instead of the above-mentioned cone rotor, compaction plates which are operated by hydraulic cylinders or the like are arranged side by side on the circumference of the earth and sand passage path, and each compaction plate is actuated in the radial direction so that the soil and sand on the outer peripheral side. It can also be pushed to the ground to enhance the consolidation effect on the ground side. In addition, it is preferable to provide a mechanism capable of efficiently consolidating the earth and sand to the ground side. In addition to the above structure, the excavator has a direction control mechanism that controls the propulsion direction of the excavator, a surveying mechanism that measures the propulsion direction of the excavator, and wiring cables and piping for supplying power and hydraulic pressure to the excavator. It is possible to provide various mechanisms similar to those of a normal excavator, such as a connecting mechanism for connecting and supporting the buried pipe to the excavator.

In order to give propulsion to the excavator, the tail end of the buried pipe row connected to the rear of the excavator may be pushed by a source push jack or the like installed in the shaft, or at the rear of the excavator. Then, the propulsion shaft body made of a steel pipe or the like may be sequentially connected to the inside of the buried pipe row, and the tail end of the propulsion shaft body may be pressed by the original push jack or the like. In this case, the buried pipe row may be pressed by the push jack separately from the propulsion shaft body, or the tip of the buried pipe row may be fixed to the excavator and the buried pipe row may be moved along with the propulsion of the excavator. Rows may be towed. further,
It is also possible to hold and fix the embedded pipe row on the propulsion shaft body that is passed through the inside thereof, and to propel the embedded pipe row together with the propulsion of the propulsion shaft body. As described above, the method of holding and fixing the embedded pipe row to the propulsion shaft body and its specific structure are described in Japanese Patent Application No. 63-2981919, which has been previously filed by the applicant of the present application.
The details are disclosed in Japanese Patent Application No. 1-183271, etc.

As the material of the buried pipe, various kinds of pipe materials used in the ordinary propulsion method such as a fume pipe, a steel pipe, a reinforced plastic pipe, a vinyl chloride pipe and the like can be used.
It can be applied to sewer pipes, gas pipes, conduit pipes, and any other underground pipes.

[0018]

[Operation] When the excavator excavates the ground with an excavation diameter larger than the outer diameter of the buried pipe and the tip large diameter portion of the excavator is propelled, the outer diameter of the tip large diameter portion becomes rear of the excavator. Since it is larger than the outer diameters of the portion and the buried pipe, a step, that is, a gap is formed between the outer diameter of the large diameter tip portion and the outer diameter of the buried pipe. If earth and sand are discharged into the voids formed behind the large diameter part of the tip, the earth and sand will not be subjected to a large resistance and the soil will be discharged very smoothly to cover the outer circumference of the buried pipe row. Therefore, it is possible to reduce the propulsive force required for propulsion.

Further, since the gap formed between the outer diameter of the large diameter portion of the tip of the excavator and the outer diameter of the buried pipe can be used as a compaction space, even if the propulsion force or compaction capacity of the excavator is small,
A buried hole having a required outer diameter can be reliably formed, and the outer diameter of the applicable buried pipe is not limited as in the conventional method described above. This will be described in detail with reference to FIG. When the outer diameter of the front part of the excavator, that is, the excavation diameter is D ₁ , the outer diameter of the buried pipe, that is, the inner diameter of the buried hole is D, the consolidable depth of the ground is t, and the volume reduction rate of the excavated soil due to consolidation is α, ^{_{π (D 1 + 2t) 2}} /4-πD 2/4 is a cross-sectional area of the voids drilling sand can compaction dumping. For this gap, the amount of sediment that must be compacted earth removal, taking into account the volume reduction ratio, a ^{_{(1-α) πD 1 2}} /4.

Therefore, the following conditions must be satisfied. ^{_{(1-α) πD 1 2}} /4 ≦ π (D 1 + 2t) 2/4-πD 2/4 , where, D ₁ = βD, putting the t / D = γ, the above equation, (1-alpha ) Β ² ≦ (β + 2γ) −1 can be rewritten.

Further, by rearranging the above equations and considering the physical meaning, β ≧ {[4γ ² + α (1-4γ ² )] ^0.5 −
Under the condition of 2γ} / α, it is possible to completely promote soil-free soil. Specifically, for example, the outer diameter of the buried pipe D = 65
cm, compression depth t = 5 cm, volume reduction rate α = 0.1, β ≧ 1.944, and the excavator excavation diameter D ₁ is D ₁
= 126.4 cm or more should be set.
Similarly, when t = 8 cm, α = 0.15 and D = 100 cm, β = 1.696 and the excavation diameter D ₁ should be set to about 170 cm.

In any case, the outer diameter D of the buried pipe and the ground condition
Excavator diameter D according to ₁Should be set appropriately
If this is the case, it will be possible to reliably promote non-removing soil, and
There is a theoretical limit to the outer diameter of the buried pipe, such as the earthmoving propulsion method.
The world does not occur. Also, the outside diameter of the buried pipe is the same.
If this is the case, the density of excavated soil will be less than that of the conventional method.
Energy required for consolidation, that is, the driving force,
The driving force of the cone rotor is small, and the propulsion mechanism and
To reduce the equipment cost and operating cost of the drive mechanism
You can

[0023]

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

FIG. 1 shows the structure of the excavator portion in a construction state. The excavator 1 propelling in the ground E has a large tip portion 10 and a rear portion having a smaller outer diameter than the large tip portion 10. And part 20. An excavation mechanism 30 including a large number of bits 31 is attached to the tip of the tip large diameter portion 10. The excavation mechanism 30 is rotationally driven by a motor 40 installed at the rear. The excavation mechanism 30 has a sediment intake port 32 that takes in the excavated soil into the excavator 1.

Behind the excavation mechanism 30 is a cone rotor 50.
Is attached, and is driven to rotate by a motor 40 like the excavation mechanism 30. The cone rotor 50 has a conical shape with a sharp tip. Excavation mechanism 30 and cone rotor 50
Inner peripheral surface 12 of the large-diameter tip 10 of the machine 1 that covers the outer periphery of the
Has a conical shape that narrows toward the rear side, contrary to the cone rotor 50. Therefore, the earth and sand sent to the rear of the excavation mechanism 30 has the inner peripheral surface 12 of the tip large diameter portion 10.
The tapered space sandwiched by the cone rotor 50 moves toward a narrower rear side. The cone rotor 50 is attached so as to be slightly eccentric with respect to the rotation shaft of the motor 40, and the entire cone rotor 50 is eccentrically rotated. Therefore, the earth and sand sent rearward along the outer periphery of the cone rotor 50 receives a radial force associated with the eccentric rotation of the cone rotor 50. Through such a process, the earth and sand or gravel stones are finely crushed or subjected to a compaction action.

Immediately behind the stepped portion between the large-diameter tip portion 10 and the rear portion 20 of the excavator 1, a rear soil discharge port 60 is opened on the outer periphery of the rear portion 20. The earth and sand moved rearward along the cone rotor 50 is discharged from the rear soil discharge port 60 to the ground side. The discharged earth and sand is housed in a gap formed between the outer diameter of the tip large-diameter portion 10 and the outer periphery of the rear portion 20, is compacted in other states, and is buried in the rear portion of the rear portion 20 (not shown). The buried hole corresponding to the outer diameter of (d) is formed.

The rear portion 20 of the excavator 1 has a large-diameter tip portion 10
The front cylinder portion 22 fixed to the rear cylinder portion 24 and the rear cylinder portion 24 for connecting the buried pipe row are flexibly connected by the direction control jack 26, and the front cylinder portion 22, that is, the large tip end diameter portion 10 and the excavation mechanism 30 are connected to each other. You can freely swing your head, and you can easily correct the propulsion direction. When the excavator 1 having the above-described structure is used to perform propulsive embedding of the embedding pipe, the excavation mechanism 30
The earth in the range corresponding to the outer diameter of the tip large diameter portion 10 is excavated, and the excavated earth and sand is collected by the earth and sand intake port 32 of the excavation mechanism 30.
It is taken into the inside of the excavator 1. The earth and sand are sent rearward along the cone rotor 50 and the cone rotor 5
The eccentric rotation of 0 pushes it toward the outer circumference. The earth and sand sent to the rear soil discharge port 60 is sent out to the void portion formed by the step between the large-diameter tip portion 10 and the rear portion 20. The excavated earth and sand and the inner wall portion of the ground are compacted to a certain thickness, whereby the whole excavated earth and sand is completely compacted on the outer peripheral portion of the buried pipe. In this way, the excavator 1 is propelled, and the buried pipe is propelled and buried in the buried hole formed behind the propulsion machine 1.
The earth and sand excavated by the excavator 1 is completely backfilled in the outer peripheral portion of the buried pipe.

Next, in the embodiment shown in FIG. 2, the structure of the soil discharge port is different from that of the above embodiment. That is, in this embodiment, the vertical wall portion existing in the step portion between the large-diameter tip portion 10 and the rear portion 20 is provided with the axial soil discharge port 64 which is open rearward in the axial direction of the excavator 1. . Axial soil discharge port 6
Since the resistance force from the ground becomes small, the earth and sand sent from 4 toward the rear can be smoothly discharged. Further, in this embodiment, the outermost earth unloading port 62 is provided which is open to the outer periphery of the large-diameter tip portion 10, that is, the outermost peripheral surface of the machine 1. Therefore, a part of the earth and sand excavated by the excavation mechanism 30 is discharged from the axial soil discharge port 64, and the remaining part is discharged from the outermost periphery soil discharge port 62.

[0029]

As described above, according to the earthless earth propulsion method for a buried pipe according to the present invention, the ground is excavated with a larger excavation diameter than the outer diameter of the buried pipe, and the excavated earth and sand is excavated. Since the gap formed between the large diameter part of the tip and the outer diameter of the buried pipe is used to consolidate and discharge the soil on the ground side,
Consolidation of soil and soil can be discharged very smoothly. In particular, by simply selecting the tip large diameter part of the excavator and the excavation diameter according to the outer diameter of the buried pipe, it is possible to easily perform propulsive embedding of a buried pipe of any diameter. It is possible to bury the medium or large diameter buried pipe, which was difficult to apply by the propulsion method, without discharging soil.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a construction state showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a construction state showing another embodiment.

FIG. 3 is a cross-sectional view of an embedding hole for explaining a consolidated state of earth and sand according to the present invention.

FIG. 4 is a cross-sectional view of an embedding hole for explaining a consolidated state of earth and sand in a conventional method.

[Explanation of symbols]

 1 excavator 10 tip large diameter part 20 rear part 30 excavation mechanism 60 rear part soil discharge port 62 outermost periphery soil discharge port 64 axial direction soil discharge port E ground

Claims (1)

[Claims] 1. A ground excavator is excavated at the tip of an excavator that propels in the ground, the excavated earth and sand is taken into the excavator, and the taken in sand is compacted and discharged to the ground side at the outer periphery of the excavator, and the excavator is excavated. In the non-removal earth propulsion method of a buried pipe, in which a buried pipe is propelled and buried in the buried hole formed in the rear of the, the large tip of the tip with a larger outer diameter than the buried pipe and the rear of the outer diameter almost the same as the buried pipe The excavator equipped with a section excavates the ground with an excavation diameter larger than the outer diameter of the buried pipe, and at least a part of the earth and sand taken into the excavator is located at a position rearward from the large-diameter tip of the excavator. The earth-free propulsion method for buried pipes, which is characterized in that the earth is discharged to the outer periphery of the excavator.