JP2625065B2 - How to build a 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 for constructing a shaft, and more particularly to a method for constructing a shaft suitable for forming a deep shaft such as a road, a railroad, and water and sewage.

[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.

[0003] 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,
It discharges earth and sand from the work room with a slab structure at the bottom and sinks it to reach a predetermined support layer.To eliminate water entering the work room, compressed air is sent to the work room. Had 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, in the case of constructing a deep shaft using the pneumatic caisson method, groundwater can be safely conquered, but the work is performed under pressure, and the work efficiency is reduced.
There was a problem that the construction period was long.

[0008] In this case, it is necessary to lay down the divided skeleton in the hole after excavation. In order to produce this skeleton at a factory and transport it to the site, the transportation cost is high, and especially large-diameter There was a problem that transportation became difficult when it became a skeleton.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to solve all of the shortening of the construction period required for a deep shaft, cost reduction, measures against high water pressure, etc. Another object of the present invention is to provide a method for constructing a shaft that can easily cope with a large-diameter shaft without problems such as transportation.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and includes a step of forming a slot in the ground by excavating muddy water with an excavator; Excavating and forming a production yard of a submerged structure continuous with the slot on the side, discharging muddy water in the production yard, casting concrete in the production yard to produce a submerged structure; Water is poured into the production yard, and the submerged structure is moved from the production yard to the slot side in the water and is submerged in the slot, and the steps of manufacturing and submerging the submerged structure are repeated to form the groove. Connecting the submerged structure within the hole;
Solidifying the gap between the outer periphery of the connected submerged structure and the hole wall of the slot.

[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.

[0012] Further, a manufacturing yard of a submerged structure is formed at the side of the above-mentioned slot so as to be continuous with the slot, and concrete is cast in the production yard in a muddy water discharge state to produce the submerged structure. By pouring water into the production yard, moving the submerged structure to the slot side in the water, and repeating the process of submerging in the slot, the submerged structure can be manufactured on site, without causing transportation problems A large diameter submerged structure can be formed.

Further, since the submerged structure is moved in water, even if the submerged structure has a large diameter and heavy weight,
It can be easily moved using buoyancy.

In addition, since operations such as excavation of a slot and submersion of a submerged structure can be processed by underwater work, it is not necessary to take special measures against high water pressure specific to a large depth.

Further, by solidifying the gap between the hole wall of the slot and the outer periphery of the submerged structure, a water stop zone can be formed, and water leakage can be prevented.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 to 8 are views showing a method of constructing a shaft according to an embodiment of the present invention.

First, as shown in FIG. 1, a mouth 14 is formed by press-fitting a mouth casing 12 into the ground 10 and then excavating the ground to a predetermined depth with a hammer club or the like. The mouth 14 is formed to be larger than the diameter of the shaft to be constructed.

On the side of the mouth 14, a manufacturing yard 2 for the submerged structure 40 is formed by excavation. This production yard 2
Is formed adjacent to the mouth 14 and is continuous with the mouth 14, and at the boundary with the mouth 14,
A gate 4 for horizontally moving 0 is provided, and the mouth 4 and the production yard 2 are partitioned by the gate 4. The manufacturing yard 2 is formed to be sufficiently larger than the size of the submerged structure 40. The inside of the production yard 2 can be injected or drained with a pipe 6.

Next, as shown in FIG.
Reverse circulation drill machine 1 as an excavator
6 is installed, and a slot 18 is formed by drilling from the mouth 14 with the reverse circulation drilling machine 16. 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 large diameter. 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 slot 18 is excavated by the reverse circulation drilling machine 16, continuous excavation can be performed, and even a shaft having a large depth of 70 m or more can be excavated in a short period of time and cost is reduced. 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 extend and contract.

Next, as shown in FIG. 3, in a state where the drill bit 26 of the reverse circulation drill machine 16 has been drilled to near the tip of the slot 18, the wing bit 32 attached to the drill bit 26 is expanded. An enlarged slot 34 is formed at the tip of the slot 18. In this case, since the enlarged slot portion 34 can be made large, the diameter of the slot 18 can be suppressed to a minimum state sufficient for inserting the shield machine, and therefore, the excavation period of the slot 18 can be shortened. It is possible to do. 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.

At the time of excavating the slot 18, muddy water is put into the production yard 2 and can be used as a muddy water supply source at the time of excavating the slot.

Next, after the excavation of the enlarged slot 34 is completed,
As shown in FIG. 4, the reverse circulation drilling machine 16 is removed, and the muddy water in the production yard 2 is discharged to the outside via the pipe 6 with the gate 4 of the production yard 2 closed. Then, with the muddy water completely removed, a formwork is installed in the production yard 2 and concrete is poured into the formwork to produce a cylindrical sinking structure 40 having a diameter slightly smaller than the slot 18. I do. The submerged structure 40 is formed to have an inner diameter larger than the divided block length of the shield machine. As described above, since the submerged structure 40 is manufactured on-site, it is possible to freely manufacture the large-diameter submerged structure 40 without causing a transportation problem.

Next, in the state where the submerged structure 40 has been manufactured, as shown in FIG.
Pour water inside. Then, the gate 4 of the production yard 2 is opened, and the submerged structure 40 is moved underwater from the production yard 2 to the slot 1.
8 and is settled in the slot 18. The movement from the manufacturing yard 2 side to the slot 18 side is performed by winding up a wire 42 connected to a winch. The submerged structure 40 is submerged in the slot 18, as shown in FIG. 6, by extending a steel wire 44 connected to a jack. As described above, by moving the submerged structure 40 in the water, even the large-diameter and heavy submerged structure 40 can be easily moved. The enlarged slot 34
On the bottom of the bottom plate 45, an adhesive concrete containing a separation reducing material is poured underwater to form a bottom plate 45.
The submerged structures 40 are stacked on top.

Then, as shown in FIG. 6, the manufacturing process and the setting process of the submerged structure 40 are repeated to
The submerged structures 40 are supplied to the inside, and each submerged structure 40 is connected in the slot 18. At the time of connection between the submerged structures 40, as shown in FIG. 8, an annular protrusion 50 having a trapezoidal cross section formed at the center of the upper surface of the submerged structure 40 and an annular protrusion 50 formed at the center of the lower surface are formed. By positioning the annular concave portions 52 in the vertical direction, positioning of the substructures 40 is performed.

Further, the respective submerged structures 40 are connected to each other by inserting a connecting steel material 55 into a sheath tube 54 penetrated in the longitudinal direction and tightening the steel tube. The space between the submerged structures 40 is sealed with a water-swellable sealing material or the like so that watertightness is maintained.

The positioning of the substructures 40 is not limited to the engagement between the annular projection 50 and the annular concave portion 52 having a trapezoidal cross section, but annular members having various cross sectional shapes such as a semicircular cross section may be employed. 9 or 10
As shown in FIG.
The hemispheric projections 56 formed at both sides of the sheath tube 4 and the hemispheric projections 57 formed at the positions corresponding to the hemispheric projections 56 on both sides of the sheath tube 54 on the lower surface are engaged. It is also possible to perform center positioning and circumferential positioning of the structures 40.

Then, with the submerged structure 40 connected in the slot 18, the gap between the hole wall of the slot 18 and the outer periphery of the submerged structure 40 is solidified with muddy water. In this way, the gap between the hole wall of the slot 18 and the outer periphery of the submerged structure 40 is solidified with muddy water, so that a water stop zone is formed therearound. Becomes possible.

Further, with the mud solidification completed, as shown in FIG. 7, a shield excavator 48 is installed at the bottom of the lowermost submerged structure 40 and formed on the side of the submerged structure 40. If the shield excavator 48 is propelled from the wellhead 46 thus formed, the enlarged slot 34 can be easily excavated and propelled, and the excavation time at the time of starting can be reduced.

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

After the shield tunnel is constructed by the shield machine 48, the shaft can be used as a foundation pile, and in this case, sufficient sectional strength can be obtained.

The present invention is not limited to the above embodiment, and various changes can be made within the scope of the present invention.

For example, although a reverse circulation drill is used as an excavator, the present invention is not limited to this, and an excavator using a jet stream and other types can also be used.

Although the wing-expanding bit is used as the diameter-expanding excavation means, the invention is not limited to this, and it is also possible to use a jet jet flow as described above, or any other means.

Further, in this embodiment, the drilling bit and the wing-spreading bit 32 are used to form the slot 18 having a circular cross section and the enlarged slot 34. However, the present invention is not limited to this. It is also possible to form an enlarged slot.

Further, although the gap between the hole wall of the slot and the outer periphery of the submerged structure is solidified with muddy water, the present invention is not limited to this, and solidification means by concrete replacement may be employed.

Further, an example in which the shield excavator is used to excavate in only one direction has been described. However, the present invention is not limited to this, and the excavation can be performed in two or more directions.

[0041]

As described above, in the method for constructing a shaft according to the present invention, by forming a slot by muddy water excavation, it is possible to easily form a slot while preventing collapse of earth and sand. It is possible to construct a deep shaft with a large diameter to some extent in a short period of time, which has the effect of shortening the construction period and reducing costs.

Further, by discharging the muddy water in the sinking structure formed continuously with the slot on the side of the slot and manufacturing the sinking structure by concrete casting, the sinking structure can be manufactured on site. Thus, there is an effect that a large-diameter submerged structure can be formed without causing a transportation problem.

Further, since the submerged structure is moved in water, even if the submerged structure has a large diameter and weight,
There is an effect that it can be easily moved.

In addition, since operations such as excavation of a slot and submersion of a submerged structure can be processed by underwater operations, there is an effect that it is not necessary to take special measures against high water pressure specific to a large depth.

Furthermore, by solidifying the gap between the hole wall of the slot and the outer periphery of the submerged structure, a water stop zone can be formed, and there is an effect that water leakage can be prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state of a mouth and a construction yard in a method of constructing a shaft according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state where a slot is formed by a reverse circulation drill machine from the state of FIG. 1;

FIG. 3 is a sectional view showing a state in which an enlarged slot is formed from the state of FIG. 2;

FIG. 4 is a cross-sectional view showing a state where a submerged structure is manufactured in a manufacturing yard.

FIG. 5 is a cross-sectional view showing a state in which a submerged structure is moved from a manufacturing yard side to a slot side.

FIG. 6 is a cross-sectional view showing a state where a submerged structure is submerged in a slot.

FIG. 7 is a cross-sectional view showing a state in which the gap between the outer periphery of the submerged submerged structure and the hole wall of the slot is solidified with muddy water and the shield machine is started.

FIG. 8 is a partial side view showing a connection state of the submerged structure.

FIG. 9 is a cross-sectional view showing another example of positioning between the submerged structures.

FIG. 10 is a plan view of the submerged structure in FIG. 9;

[Explanation of symbols]

 2 Manufacturing Yard 4 Gate 12 Mouth Casing 14 Mouth 16 Reverse Circulation Drilling Machine 18 Slot Hole 28 Mud Water 32 Spread Bit 40 Submerged Structure 42 Wire 44 Steel Wire 46 Wellhead

Claims (1)

(57) [Claims] 1. A step of forming a slot in the ground by excavating muddy water with an excavator; and a step of excavating and forming a yard for making a submerged structure continuous with the slot at a hole side of the slot. Draining the muddy water in the production yard, casting concrete in the production yard to produce a submerged structure, pouring water into the production yard, and submerging the submerged structure in the water from the production yard. Moving to the hole side to settle in the slot; repeating the manufacturing step and the setting step of the set-down structure to connect the set-up structure in the slot; and an outer periphery of the connected set-up structure And a step of solidifying a gap between the slot and the hole wall of the slot.