JP2526333B2 - How to build a vertical shaft - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing a vertical shaft, and more particularly to a method of constructing a vertical shaft suitable for forming a starting vertical shaft for deep tunnels such as roads, railways, water and sewers.

[0002]

2. Description of the Related Art Conventionally, when constructing a deep shaft having a depth of 70 m or more, a continuous underground wall or a pneumatic caisson method has been adopted in order to prevent high water pressure.

In the deep shaft using the continuous underground wall,
Circular rings were sequentially constructed from the top every 3 to 4 m, and concrete shafts were constructed from the top to the bottom to form a support along the continuous wall.

In the pneumatic caisson method,
The work chamber with a slab structure at the bottom is designed to sink the soil and reach it to reach a predetermined support layer.In order to remove water that enters the work chamber, compressed air is supplied to the work chamber. I was trying to supply.

[0005]

In the conventional deep shaft using the continuous underground wall, it is necessary to construct a circular ring and to concrete concrete every 3 to 4 m excavation. There was a problem that it could take several years.

[0006] In addition, there is a high risk of boiling or bulging due to the infiltration of high-pressure groundwater from the lower end of the underground wall.

Further, when constructing a deep shaft by the pneumatic caisson method, groundwater can be safely conquered, but it is work under pressure, and if the pressure increases,
Due to health management, it takes a lot of time to pressurize and depressurize, and the actual work time is extremely short, the work efficiency is reduced, and the construction period is long.

The present invention has been made in view of the above-mentioned conventional problems, and the purpose thereof is to shorten the construction period required for a deep shaft, reduce costs, prevent high water pressure, etc. It is to provide a method of constructing a vertical shaft that enables various construction.

[0009]

The present invention is made to achieve the above object, and the invention of claim 1 is to make a muddy water excavation by an excavator equipped with a diameter expanding excavation means to the underground. A step of forming a slot, a step of forming an enlarged slot portion at the tip of the slot by using the diameter-expanding excavating means, and a step of submerging a tubular watertight structure in the slot. And a step of solidifying a gap between the hole wall of the groove hole and the outer periphery of the watertight structure, wherein the bottom of the watertight structure is used as a starting hole for a shield machine. .

The invention of claim 2 provides the watertight structure according to claim 1, wherein the watertight structure is assembled by connecting a precast concrete slab through a watertight joint, and the bottom side wall of the watertight structure has a removable lid. After solidifying the gap between the hole wall of the slot and the outer periphery of the watertight structure, the lid is removed and the shield machine is started from there.

[0011]

According to the method of constructing a shaft having the above-described configuration, by forming a slot in the ground by excavating muddy water with an excavator, the slot can be easily formed while preventing collapse of earth and sand.
In addition, a shaft with a large diameter and a large depth can be constructed in a short period of time, and the construction period can be shortened and the cost can be reduced.

Further, by forming the enlarged groove hole portion by using the diameter expanding and excavating means of the excavator, the tip end portion of the groove hole can be easily enlarged, and the size of the enlarged groove hole portion is sufficiently large. With this, it becomes easy to carry in and assemble the shield machine, it becomes possible to improve excavation efficiency, and further cost reduction can be expected.

Further, since the work such as excavation of the groove hole, the sinking of the watertight structure and the formation of the enlarged groove portion can be performed by underwater operation, it is not necessary to take special measures for high water pressure peculiar to large depth. .

Furthermore, by solidifying the gap between the hole wall of the groove and the outer periphery of the watertight structure, a water stop zone can be formed, which is a measure against water leakage and also serves as start protection for the shield machine. It becomes possible.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the drawings.

1 to 6 are views showing a method of constructing a shaft according to an embodiment of the present invention.

First, as shown in FIG. 1, after the mouth casing 12 is press-fitted into the ground 10, the mouth 14 is excavated to a predetermined depth by a hammer mug or the like to form the mouth 14. The mouth 14 is formed to be larger than the diameter of the shaft to be constructed.

Next, as shown in FIG.
Reverse circulation drill machine 1 as an excavator
6 is installed, and the reverse circulation drill machine 16 excavates from the mouth 14 to form a slot 18. This reverse circulation drill machine 16
A rotary table 22 is mounted on a base 20 installed on the mouth 14, and a hollow drill rod 24 is suspended from the rotary table 22, and a drill bit 26 is mounted on the tip of the drill rod 24. Then, the drill bit 26 is rotated by the rotary table 22 and the drill rod 24, and the drill bit 26 is rotated by the rotation of the drill bit 26 so that the excavated earth and sand is removed from the drill rod 24.
The water is sucked up along with the water, discharged to the outside of the slot 18 and led to the sedimentation basin. After the sediment is settled, the surface water is returned to the slot 18 again, and the muddy water 28 is put into the slot 18. The excavation is to be carried out while standing. In this case, muddy water 28
At the same time, the water pressure of the muddy water opposes the lateral pressure, and at the same time, the clay and silt fine particles of the muddy water 28 penetrate and adhere to the wall to form a mud film
Since the collapse of earth and sand can be prevented, and the flow of water is in reverse circulation, the flow velocity in the drill rod 24 is high, but the
Since the internal flow is very slow, there is little fear that the inner wall of the slot 18 will be damaged.

The drill bit 26 has a diameter of 7 m to 12 m.
The thing with a large diameter of about m is used. The drill bit 26 is shaken by a stabilizer 30 attached to the drill rod 24, so that stable drilling can be achieved.

As described above, since the reverse circulation drilling machine 16 excavates the slot 18, continuous excavation can be performed, and even a shaft with a large depth of 70 m or more can be excavated in a short period of time, and the cost is high. It can be reduced.

Further, a wing expanding bit 32 as a diameter expanding digging means is attached to the digging bit 26 so as to be expandable and contractible.

Next, as shown in FIG. 3, with the excavation bit 26 of the reverse circulation drill machine 16 being excavated to the vicinity of the tip of the slot 18, the expanding blade bit 32 attached to the excavation bit 26 is expanded, The enlarged slot portion 34 is formed at the tip of the slot 18. In this case, since the diameter of the expanding blade bit 32 is set to 12 m to 15 m and the enlarged groove hole portion 34 can be made large, the diameter of the groove hole 18 is set to a minimum state sufficient for inserting the shield machine. Therefore, the excavation period of the slot 18 can be shortened. When excavating with the wing bit 32, the stabilizer 30 is positioned in the slot 18, and only the dig bit 26 and the wing bit 32 are excavated by moving the slide rod 36. We try to stabilize the time.

Next, after excavation of the enlarged slot portion 34,
As shown in FIG. 4, the reverse circulation drill machine 16 is removed, and the tubular watertight structure 40 is sunk in the slot 18. The watertight structure 40 is formed to have an inner diameter larger than the divided block length of the shield machine, and a plurality of short tubular structural members 41 formed of a precast concrete slab or the like are vertically watertight joints. It is assembled and connected in a long tube shape in a watertight state. Further, as shown in FIG. 6, at the bottom of the watertight structure 40, a side wall is formed with a pit 46 for launching a shield machine, and the pit 46 is removed so that the lid 42 can be sealed. It has become. Then, the connected watertight structure 40 is hung by a crane or the like to be submerged in the slot 18. In this case, the muddy water 44 is injected into the watertight structure 40 to adjust the buoyancy and sink the muddy water. Further, a gap is formed between the outer periphery of the watertight structure 40 and the inner peripheral surface of the groove 18, and when the watertight structure 40 or the like sinks, the muddy water 28 in the groove 18 is added. There is no need to perform a special draining operation of the muddy water 28 that is pressurized and discharged from the mouth 14, and that is inside the slot 18. The watertight structure 40 is appropriately added and inserted into the slot 18.

Then, in the state where the bottom of the watertight structure 40 is settled down to the bottom of the enlarged groove portion 34, the gap between the hole wall of the groove 18 and the outer periphery of the watertight structure 40 is solidified with muddy water. In this way, by solidifying the gap between the hole wall of the groove hole 18 and the outer periphery of the watertight structure 40 with muddy water, a water stop zone is formed around the gap, which is a measure against water leakage and also serves as a shield starting protection. It becomes possible.

Further, in the state where the solidification of the muddy water is completed, as shown in FIG. 5, the lid body 4 for sealing the wellhead 46 is closed.
When 2 is removed and the shield machine 48 is installed at the bottom of the watertight structure 40 and the shield machine 48 is propelled from the wellhead 46, the enlarged groove hole portion 34 can be easily excavated and propelled. It is possible to shorten the time for excavation.

The shield machine 48 may be assembled on the ground and carried in, or assembled in the watertight structure 40.

After constructing the shield tunnel by the shield machine 48, the standing pile can be used as a foundation pile, and in this case, sufficient cross-section strength can be obtained.

The present invention is not limited to the above embodiments, but various modifications can be made within the scope of the present invention.

For example, although the reverse circulation drill machine is used as the excavator, the excavator is not limited to this, and it is also possible to use an excavator using a jet jet or the like.

Further, although the expanding blade bit is used as the diameter expanding and excavating means, the invention is not limited to this, and it is also possible to use a jet jet or another one as described above.

Further, in this embodiment, the excavating bit and the expanding blade bit 32 are used to form the slot 18 and the enlarged slot portion 34 having a circular cross section, but the present invention is not limited to this, and the slot having a rectangular cross section is also provided. Also, it is possible to form the enlarged slot portion.

Further, although the watertight structure 40 is made of a precast concrete slab, the watertight structure 40 is not limited to this and may be made of a steel material.

Further, the gap between the hole wall of the groove hole and the outer periphery of the watertight structure is made to be solidified with muddy water, but the present invention is not limited to this, and solidification means by concrete replacement can also be adopted.

Further, an example in which the shield machine excavates in only one direction is shown, but the invention is not limited to this, and it is also possible in two or more directions.

Further, the slot hole and the enlarged slot portion are not limited to the circular cross section, but can be formed to have a rectangular cross section.

[0036]

As described above, in the method of constructing a shaft according to the present invention, muddy water is excavated by an excavator to form a groove hole in the ground, thereby preventing the collapse of the earth and sand and making it easy. A groove can be formed in the shaft, and a deep shaft with a relatively large diameter can be constructed in a short period of time, which can shorten the construction period and reduce the cost.

Further, by forming the enlarged groove hole portion by using the diameter expanding excavating means of the excavator, the tip portion of the groove hole can be easily enlarged, and the size of the enlarged groove hole portion is sufficiently large. With this, it becomes easy to carry in and assemble the shield machine, it becomes possible to improve excavation efficiency, and further cost reduction can be expected.

Further, since the work such as excavation of the groove hole, the sinking of the watertight structure, and the formation of the expanded groove portion can be performed by underwater operation, it is not necessary to take special measures for high water pressure peculiar to the large depth. .

Further, by solidifying the gap between the hole wall of the groove hole and the outer periphery of the watertight structure, a water stop zone can be formed, which is a measure against water leakage and also serves as a start protection for the shield machine. be able to.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which a mouth is constructed in a method for constructing a vertical shaft according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a slot is formed by a reverse circulation drill machine from the state of FIG.

FIG. 3 is a cross-sectional view showing a state in which an enlarged slot portion is formed from the state of FIG.

FIG. 4 is a cross-sectional view showing a state in which a watertight structure is submerged in a slot formed by a reverse circulation drill machine.

FIG. 5 is a cross-sectional view showing a state in which the gap between the outer periphery of the watertight structure that has been sunk in FIG. 4 and the hole wall of the groove hole is solidified with muddy water and the shield machine is started.

FIG. 6 is a partially cutaway perspective view showing a state of the bottom portion of the watertight structural material.

[Explanation of symbols]

12 Mouth Casing 14 Mouth 16 Reverse Circulation Drill Machine 18 Groove 28 Muddy Water 32 Expanding Blade Bit 34 Expanding Groove 40 Watertight Structure 46 Wellhead
TD004701

Claims (2)

(57) [Claims] 1. A step of performing muddy water excavation by an excavator having a diameter-expanding excavation means to form a groove hole in the ground, and an enlarged groove hole portion using the diameter-expansion excavating means at the tip of the groove hole. And a step of depositing a tubular watertight structure in the groove hole, and a step of solidifying a gap between the hole wall of the groove hole and the outer periphery of the watertight structure. A method for constructing a vertical shaft, wherein the bottom of the watertight structure is used as a starting hole for a shield machine. 2. The watertight structure according to claim 1, wherein the watertight structure is assembled by connecting a precast concrete slab with a watertight joint, and a bottom side wall of the watertight structure includes a removable lid, and the hole wall of the groove hole is formed. A method for constructing a shaft, comprising solidifying a gap between the watertight structure and the outer periphery of the watertight structure, removing the lid, and starting the shield machine from there.