JP2002047881A - Pipeline construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipeline construction method for constructing a pipeline at a great depth without trouble by constituting cut-off structure provided at a starting portal and an arrival portal, to cope with high water pressure at the great depth. SOLUTION: In this pipeline construction method for forming the pipeline in the ground by an advancing pipe, a starting portal unit 24 combining an impervious chamber 22 opened to the inner peripheral surface with an expandable shielding rubber ring 23 is fixedly disposed at the vertical face on the pipeline construction side of the starting portal 21. A boring machine 26 is pushed in until it faces the inside of the impervious chamber 22, and the outer periphery of the boring machine 26 is watertightly clamped by the shielding rubber ring 23. A filling agent (a) is then filled and retained in the impervious chamber 22 at a pressure higher than underground water pressure, and excavation by the boring machine 26 and the push-in of an advancing pipe 61 are carried out while cutting off water to construct the pipeline.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipeline construction method for forming a pipeline in the ground, and more particularly, to a pipeline construction method for effectively preventing the generation of groundwater at a start port and an arrival port. About.

[0002]

2. Description of the Related Art A propulsion method for constructing a pipeline underground involves excavating a drilling machine from a starting wellhead to a reaching wellhead,
Accordingly, concrete, steel pipes, and ductile propulsion pipes are sequentially connected and pushed into the ground, thereby forming a pipeline.

In such a pipeline construction method, when an excavator encounters a groundwater vein at a starting wellhead, groundwater is spouted at the time of pushing a propulsion pipe, and an excavator emerges at a reaching wellhead. Sometimes groundwater also gushes.

[0004] For this reason, it is necessary to provide a water stop structure for preventing the spouting of groundwater at the starting wellhead and the reaching wellhead.

FIG. 6 (A) shows a conventional water-stop structure employed in the starting wellhead 1, in which the excavator 3 is mounted on the vertical wall 2 of the starting wellhead 1 made of concrete or steel plate on the pipeline construction side. A wellhead block 5 made of concrete or steel plate having a through hole 4 passing therethrough is fixed, and a wellhead rubber packing 6 is attached to an end of the excavator 3 at the entrance side. After the chemical injection treatment, a through hole 7 for the excavator 3 is formed in the vertical wall 2, and the excavator 3
And the excavator 3 and the propulsion pipe 8 following it
The outflow portion of the groundwater from the entry portion to the starting wellhead 1 is stopped by the wellhead rubber packing 6.

FIG. 6 (B) shows a conventional water shutoff structure employed in the reaching wellhead 9, and the excavator 3 of the reaching wellhead 9.
The through hole 1 through which the excavator 3 passes
1 is fixed to a wellhead block 12 made of concrete or steel plate, and a wellhead rubber packing 1 is provided at an end of the through hole 11 on the exit side.
After the excavator 3 reaches the soil at the portion where the excavator 3 reaches, the through hole 14 of the excavator 3 is formed in the vertical wall 10, and the excavation that has come out of the through hole 14 is performed. The outflow of groundwater from the machine 3 and the subsequent take-out portion of the propulsion pipe 8 is stopped by the wellhead rubber packing 13.

[0007]

Conventionally, the construction of underground pipelines in public works and the like has mainly been carried out at about 10 m underground, and the water pressure of groundwater generated at such a depth is relatively low. Therefore, it is possible to cope with the water blocking structure using the wellhead rubber packings 6 and 13 described above.

In recent years, in order to make effective use of the underground, policies have been taken to deviate from personal rights below 40 m below the ground. For this reason, pipelines to be constructed in the future will be constructed at a large depth below 40 m below the ground. More things.

As described above, when the portion where the pipeline is to be constructed is at a large depth, the water pressure of the groundwater at the large depth becomes very high.
In the water stop structure using No. 3, a sealing function corresponding to high water pressure at a large depth cannot be obtained, and a new water stop structure dedicated to a large depth needs to be developed.

Accordingly, an object of the present invention is to provide a water shutoff structure provided at a starting wellhead and a reaching wellhead so as to be able to cope with high water pressure at a large depth, and to construct a pipe at a large depth without any trouble. It is to provide a road construction method.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention pushes an excavator and a propulsion pipe following the excavation machine from a starting wellhead to a reaching wellhead, and the pipeline is driven underground by the propulsion pipe. In the pipeline construction method of forming a tunnel, a starting wellhead unit combining a watertight chamber opening on the inner peripheral surface and a scalable shielding rubber ring is fixedly arranged on the vertical surface of the starting wellhead on the pipeline construction side, and the excavator Into the impermeable room and tighten the outer periphery of the excavator with a shielding rubber ring in a watertight manner. The structure that excavates and pushes the propulsion pipe is adopted.

Further, another invention relates to a pipeline construction method in which an excavator and a propulsion pipe following the excavator are pushed from a starting wellhead to a reaching wellhead, and a pipeline is formed underground by the propulsion pipe.
The arrival wellhead unit, which combines a scalable shielding rubber ring and a hollow water-impervious chamber, is fixedly arranged on the vertical surface where the machine at the arrival well reaches, and the injection chamber is filled with the injection agent at a pressure higher than the groundwater pressure. When the excavator that has been held and comes out of the arrival wellhead passes through the shielding rubber ring, the outer circumference of the excavator is tightened in a watertight manner with the shielding rubber ring, and thereafter the filling of the injection material is stopped, and the wellhead provided in the watertight chamber , And the excavator is pushed out of the arrival well unit from here.

The above-mentioned shielding rubber ring is formed into an annular shape corresponding to the outer diameter of the excavator and the propulsion pipe by a combination of a plurality of divided bodies, and can be expanded and contracted by moving means for moving each divided body in the radial direction. As the moving means, in addition to a manual operation performed by rotating a screw with a handle, an interlocking automatic operation using a hydraulic or pneumatic jack can be adopted.

[0014]

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

The first embodiment shown in FIGS. 1 and 2 shows a water blocking structure of a starting wellhead 21, and a water-shielding chamber opened on the inner peripheral surface of a vertical wall 25 on the pipeline construction side of the starting wellhead. A starting wellhead unit 24 in which a shielding rubber ring 23 that can be expanded and contracted is combined with a starting wellhead unit 24 in a fixed manner. The starting well 21
Vertical wall 25 is made of steel plate or concrete.

The starting wellhead unit 24 is made of steel plate or concrete and has an outer cylinder 27 having a larger diameter than the excavator 26.
A partition wall 29 having a circular hole 28 through which the excavator 26 can pass is provided in the middle of the inside, and a distal end wall 31 having a similar circular hole 30 is provided at the distal end of the outer cylinder 27 to shield the first half in the outer cylinder 27. The storage chamber 32 for the rubber ring 23 is provided, and the latter half is used as the water-blocking chamber 22 having an inner peripheral surface opened, and is fixed to a vertical surface on the pipeline construction side by a flange 33 provided on the outer periphery of the rear end of the outer cylinder 27. It has become. This fixing is performed by welding when the vertical wall 25 of the starting wellhead 21 is a steel plate, or by using anchor bolts when the vertical wall 25 is concrete.

The tip wall 31 of the starting wellhead unit 21
A wellhead rubber packing 34 is attached around the circular hole 30 in the above.

At the portion of the outer cylinder 27 in the impermeable chamber 22, a filling port 35 for the infusate a, and a pressure gauge 36 for detecting and extracting the pressure of the infusate a filled in the impermeable chamber 22 and displaying the pressure simultaneously. Are provided. The injection agent a is a two-part liquid in the case shown in the figure, and is separately filled with the liquid A and the liquid B.
The mixture in the chamber 2 becomes a semi-gel state or a jelly state, so that the water barrier chamber 22 is always filled with a high pressure and a pressure higher than the groundwater pressure.

The injection of the injection agent a into the impermeable chamber 22 is as follows.
By the automatic detection of the pressure gauge 36, the valve 38 of the injection pipe 37 connected to the filling port 35 is opened and closed, and when the pressure in the water-tight chamber 22 is reduced, the injection agent a is filled immediately. Is automatically maintained at a constant pressure. In addition, you may make it use the one-part thing for the injection material a.

The second embodiment shown in FIGS. 4 and 5 shows a water stopping structure of the reaching well 41, and the excavator 2 of the reaching well 41
A reaching wall unit 44 in which a scalable shielding rubber ring 42 and an inner hollow water-tight chamber 43 are combined with a vertical wall 51 where 6 reaches, and a vertical wall 51 of the reaching well 41 similar to the first embodiment are provided on the vertical wall 51 of the reaching well 41. They are fixedly arranged under conditions.

The reaching wellhead unit 44 is made of steel plate or concrete, and has a partition wall 47 having a circular hole 46 through which the excavator 26 can pass inside an outer cylinder 45 having a diameter larger than that of the excavator. A front end wall 49 having a similar circular hole 48 is provided at the rear end of the outer cylinder 45, the latter half of the outer cylinder 45 is used as a storage chamber 50 for the shielding rubber ring 42, and the former half is used as a hollow water-impervious chamber 43. A flange provided on the outer periphery of the front end of the outer cylinder 45 is fixed to the vertical wall 51 on the pipeline construction side.

The circular hole 48 in the end wall 49 is closed by a removable lid member 52, and a wellhead rubber packing 53 is attached around the circular hole 48.

A filling port 54 for the injectant and a pressure gauge 55 for detecting and taking out the pressure of the injectant a filled in the impermeable chamber 43 at the portion of the outer cylinder 45 in the impermeable chamber 43 are provided. Are provided. This injection a is a two-part liquid, and is separately filled with the liquid A and the liquid B, and becomes a semi-gel state or a jelly state by mixing in the impermeable chamber, similar to the case of the start well unit 21 described above. , Injection agent a into impermeable room 4
3 is automatically filled with a constant pressure equal to or higher than the groundwater pressure at all times.

FIG. 5 shows a shielding rubber ring 4 in a storage room 50.
2 shows an example in which two sets are arranged before and after to improve the water stopping effect.

FIG. 2 shows the structure of the shielding rubber rings 23 and 42. The excavator 2 is constructed by combining a plurality of divided bodies 56.
6 and a moving means 57 for moving each divided body 56 in the radial direction so as to have an annular shape corresponding to the outer diameter of the main body 26a and the propulsion pipe 61.
Can be scaled. Since the starting wellhead and the reaching wellhead have the same structure, the example for the starting wellhead will be mainly described.

The moving means 57 includes the shielding rubber ring 2
A holding portion 58 of the divided body 56 is provided inside the storage chambers 32, 50 of the third and the second 42, and the divided body 56 is movably held in the radial direction by the holding portion 58. The supported screw shaft 59 is connected to the divided body 56, and by turning the screw shaft 59 with the handle 60, the divided body 56 is moved in the radial direction. This moving means 57
In addition to the manual operation as shown in the figure, an interlocking automatic operation using a hydraulic or pneumatic jack can be adopted.

The reason why the arrangement diameter of the shielding rubber ring 23 can be enlarged or reduced is to allow the slightly larger diameter cutting blade 26b provided at the tip of the main body 26a of the excavator 26 to pass through without difficulty.

That is, until the cutting blade 26b passes, the arrangement diameter of the divided body 56 of the shielding rubber rings 23 and 42 is increased, and when the cutting blade 26b passes, the diameter is reduced.
The inner peripheral surface of the divided body 56 can be pressed against the outer peripheral surface of the excavator 6a. The propulsion pipe 61 following the excavator 26 has substantially the same diameter as the main body 26a.
3 and 42 are pressed against the propulsion pipe 61 in the same manner.

Divided body 5 of shielding rubber rings 23 and 42
In FIG. 6, as shown in FIG. 3 (E), the inner peripheral surface is inclined at an angle of about 1 to 10 ° with respect to the axial direction, so that a reliable press contact margin can be secured and the frictional force is reduced. The end of the adjacent divided body 56 is formed as shown in FIG.
As illustrated in FIGS. 3A to 3D, the step in FIG. 3A, the unevenness in FIG. 3B, the chevron in FIG.
Are connected in the axial direction by the waveforms and the like, so that the displacement of the body 26a of the excavator 26 and the movement of the propulsion pipe 61 do not occur in the axial direction while maintaining watertightness.

Next, a description will be given of a pipeline construction method using the above-mentioned water stop structure of the starting wellhead and the reaching wellhead.

First, as shown in FIG. 1, a through hole 62 of the excavator 26 was formed in the vertical wall 25 of the starting well 21 on the pipeline construction side, and the starting well 21 was put into the starting well 21. The starting wellhead unit 24 is fixed to the vertical wall 25 on the pipeline construction side so as to be coaxial with the passage hole 62.

The passage hole 62 is formed in the vertical wall 25 on the pipe construction side.
When drilling the through hole 62, a medicine is injected into the ground where the passage hole 62 is drilled in advance and solidified to prevent the occurrence of groundwater spurting due to the drilling of the passage hole 62.

The injection pipe 37 for the injection agent is connected to the injection port 35 for the injection agent a provided in the outer cylinder 27 of the water shield chamber 22, and the excavator 26 is provided on the tip end wall 31 of the start well unit 21. The circular hole 30 was inserted from the wellhead rubber packing 34 into the shield rubber ring 23 whose diameter was enlarged, and was pushed until the cutting blade 26b at the tip thereof was positioned in the water shield chamber 22 as shown by a dashed line in FIG. Thereafter, the diameter of the shielding rubber ring 23 is reduced, and the outer periphery of the main body 26a is watertightly tightened.

In this state, the water impervious chamber 22 is filled with the injection agent a, and the excavation of the excavator 26, the pushing of the propulsion pipe 61, and the replenishment of the propulsion pipe 61 are repeated by repeating the excavation of the excavator 26, which has reached the ground through the passage hole 62. Start building the road.

The injection material a filled in the water shielding chamber 22 so as to fill it is prevented from flowing out into the starting wellhead 21 by the shielding rubber ring 23, and a part thereof is passed through the passage hole 62 and the main body of the excavator 26. Although it flows out into the tail void 63 formed by excavation with the cutting blade 26b on the outer periphery of the cutting blade 26b, since the tail void 63 is filled with the mud and the tail void agent from the excavator 26, the outflow of the injection agent a is slight. The impervious chamber 22 is always filled with the injection agent a and its pressure is set to a pressure equal to or higher than the underground water pressure.

As a result, at the starting wellhead 21,
The portion of the excavator 26 and the propulsion pipe 61 that penetrates into the ground can be kept watertight by the double structure of the injection agent a of the starting wellhead unit 24 and the shielding rubber ring 23, and the pressure of the injection agent a is reduced by the groundwater pressure. By always automatically setting the above pressure, it is possible to construct a pipeline at a large depth.

Next, as shown in FIG. 4, the vertical wall 5 of the arrival well 41 on the side where the excavator 26 reaches is reached.
First, before the excavator 26 arrives, the through holes 6 of the excavator 26
4, the reaching well unit 44 placed in the reaching well 41 is fixed to the vertical wall 51 on the side where the excavator 26 reaches, in a coaxial arrangement with the passage hole 64.

The vertical wall 51 on the side where the excavator 26 reaches
When the passage hole 64 is drilled, a medicine is injected in advance into the ground where the passage hole 64 is drilled and solidified to prevent the generation of groundwater spouting due to the drilling of the passage hole 64.

The injection pipe for the injection agent a is connected to the injection port 54 for the injection agent a provided at the outer cylinder 45 in the water-shielding chamber 43, and the excavated machine 26 reaches the passage hole 64 and is extruded. The shielding rubber ring 42 whose diameter is increased by the cutting blade 26b at the tip.
Through the main body 2
The outer periphery of 6a is tightened in a watertight manner.

In this state, the water impervious chamber 43 is filled with the injectant a, and the impregnant a filled so as to fill the water impervious chamber 43 is prevented from flowing into the arrival well 41 by the shielding rubber ring 42. When the extruded tip of the excavator 26 reaches the tip wall 49 of the reaching wellhead unit 44, filling of the injection agent a is stopped, the lid member 52 is removed from the tip wall 49, and the circular hole 48 of the tip wall 49 is opened. By doing, excavator 2
6 is taken out of the circular hole 48 to complete the construction of the pipeline, and when the excavator 26 passes through the circular hole 48, the main body 26a of the excavator 26 and the circular hole 48 are connected by a wellhead rubber packing 53. Keep it watertight.

Thus, the portion of the reaching well 41 that comes out of the reaching well 41 of the excavator 26 is formed by the injection agent a of the reaching well unit 44 and the shielding rubber ring 42.
It can be kept watertight, and by setting the pressure of the injection agent a to a pressure equal to or higher than the underground water pressure, it becomes possible to construct a pipeline at a large depth.

[0042]

As described above, according to the present invention, at the starting wellhead, the portion of the excavator and the propulsion pipe entering the ground is kept watertight by the injection agent and the shielding rubber ring of the starting wellhead unit. In addition, at the reaching wellhead, the part of the machine coming out to the reaching wellhead can be kept watertight by the injection agent and the shielding rubber ring of the arrival well unit. By automatically setting the above pressure, the sealing function of the part that goes into the ground of the excavator and the propulsion pipe and the part that comes out at the entrance of the excavator can be enhanced, and it can respond to high water pressure groundwater, This makes it possible to construct a pipeline even under conditions where the pressure of groundwater is very high at large depths.

Further, the shielding rubber ring is formed into an annular shape by a combination of a plurality of divided bodies, and can be expanded and contracted by moving means for moving each divided body in a radial direction, so that the passage of a cutting blade having a large diameter of the excavator is released. The shield rubber ring is not damaged when passing through the excavator, and the water stopping function can be reliably maintained.

Further, since the starting wellhead unit and the reaching wellhead unit need only be transported and attached to the starting wellhead or the reaching wellhead by unitization, the construction of the pipeline can be performed simply and efficiently.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view showing a water stop structure of a starting wellhead.

FIG. 2 is a longitudinal sectional side view along the arrow II-II in FIG.

FIGS. 3A to 3D are enlarged cross-sectional views illustrating different examples of a coupling structure in a divided body of a shielding rubber ring, and FIG. 3E is a cross-sectional view illustrating an inclined surface of the shielding rubber ring.

FIG. 4 is a vertical cross-sectional front view showing a water stop structure of a reaching wellhead.

FIG. 5 is a vertical cross-sectional front view of another example showing a water stop structure at a reaching wellhead.

FIG. 6A is a vertical sectional front view showing a conventional water stop structure of a starting wellhead, and FIG. 6B is a vertical front view showing a conventional water stop structure of a reaching wellhead.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Start well 22 Water-blocking room 23 Shield rubber ring 24 Start well unit 25 Peripheral wall 26 Excavator 27 Outer cylinder 28 Circular hole 29 Partition wall 30 Circular hole 31 Front wall 32 Storage room 33 Flange 34 Wellhead rubber packing 35 Filling agent filler 36 Pressure gauge 41 Arrival wellhead 42 Shield rubber ring 43 Waterproof chamber 44 Ultimate wellhead unit 45 Outer cylinder 46 Circular hole 47 Partition wall 48 Circular hole 49 Tip wall 50 Storage room 52 Cover member 53 Wellhead rubber packing 54 Waterproof chamber 55 Pressure gauge 56 divided body 57 moving means

Claims (3)

[Claims] In a pipeline construction method in which an excavator and a propulsion pipe following the excavator are pushed from a starting wellhead to a reaching wellhead, and a pipeline is formed in the ground by the propulsion pipe, a vertical construction side of the starting wellhead is constructed. On the surface, a starting wellhead unit that combines a watertight room that opens on the inner peripheral surface and a scalable shielding rubber ring is fixedly arranged, and the excavator is pushed in until it faces the watertight room, and the outer periphery of the excavator is sealed with the shielding rubber ring. Pipeline construction method characterized by excavating with a drilling machine and pushing a propulsion pipe while filling and holding the injectant in the watertight chamber at a pressure higher than the groundwater pressure and then stopping the water after tightening in a watertight manner. 2. A pipeline construction method in which an excavator and a propulsion pipe following the excavator are pushed from a starting wellhead to an arrival wellhead, and a pipeline is formed underground by the propulsion pipe. On the surface, a reaching wellhead unit combining a scalable shielding rubber ring and an inner hollow watertight chamber is fixedly arranged, and the injectant is filled and held at a pressure higher than the groundwater pressure in the watertight chamber, and came out to the reaching wellhead When the excavator passes through the shield rubber ring, the outer circumference of the excavator is tightened in a watertight manner with this shield rubber ring, after which filling of the injection agent is stopped, the wellhead provided in the water shield chamber is opened, and the excavator arrives from here A pipeline construction method characterized by being pushed out of a wellhead unit. 3. The shield rubber ring according to claim 1, wherein the shielding rubber ring is formed into an annular shape by a combination of a plurality of divided bodies, and can be expanded and contracted by moving means for moving each divided body in a radial direction. Pipeline construction method described.