JP2640542B2 - Waterproof shaft construction method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method of constructing a water-blocking shaft in the ground at a civil engineering construction site or the like.

(Conventional technology) When constructing a water-blocking shaft on the ground at a civil engineering construction site or the like, the construction site is often narrow and a large steel sheet pile driving machine or the like cannot be carried in.

In the aquifer ground, a liner-type shaft combined with ground improvement has been adopted.
In addition to the double cost, it often has an adverse effect on adjacent structures, and there is a compensation problem for this.

As described above, in the conventional shaft construction method, it is extremely difficult or impossible to construct a shaft in a narrow place, in an aquifer, or in a place where the surrounding ground subsidence occurs due to a spring. Even if the shaft can be built using the conventional shaft construction method, the construction cost is extremely high and often adversely affects the area around the construction site.

(Problems to be Solved by the Invention) The problem to be solved by the present invention is to improve the conventional shaft construction method so that the shaft can be built even in a narrow place or in aquifer ground, and the construction cost is low. It is an object of the present invention to provide a water-blocking shaft construction method that does not adversely affect the surrounding area of the site.

(Means for Solving the Problems) The gist of the present invention that has solved the problems is as follows: 1) A spiral having a short pipe having a wing bit at a tip in a partition inside the tip head and a hollow pipe as a rotation axis. Prepare a drill, a high-pressure water injection nozzle, a water injection pipe, and a high-pressure air injection pipe, and set the lower end of the tip head toward the underground. The ground is excavated with the rotation of the wing bit of the head and the jet water from the high-pressure water jet nozzle, and the mud is advanced with the spiral drill. To form a shaft up to a predetermined depth, then inject a hardening agent into the shaft bottom through the hollow pipe of the rotary shaft of the spiral drill, and then withdraw the tip head hand A method for constructing a water-blocking shaft by hardening a hardener 2) Strongly gripping a ground anchor tensile material having one end fixed in the ground, and applying pressure to an upper portion of a side wall as a reaction force base. 3. The water-blocking shaft construction method according to 1), 3) concrete is used as a hardening agent, 3) the water-blocking shaft construction method according to claim 1 or 2, 4) a side wall made of concrete or synthetic resin is used. The watertight shaft construction method according to any one of claims 1 to 3.

(Operation) In the present invention, a cylindrical side wall is loaded on a cylindrical tip head to which a digging device and a mud discharging device are attached, and the ground is digged and evacuated by the digging device of the tip head utilizing the weight of the side wall. It progresses while discharging mud with a mud device.
Then, as the tip head advances, the side walls are sequentially added to form a shaft to a predetermined depth. After that, a hardening agent such as concrete is poured and poured into the shaft bottom through the hollow pipe of the rotary shaft of the spiral drill, and then the tip head is withdrawn and the hardening agent is hardened to complete the water stop shaft. It has become.

In the present invention, when excavating underground with the tip head, not only utilizes the weight of the side wall loaded on the tip head, but also strongly grips the ground anchor tensile material previously installed on the shaft construction site as a reaction force base Pressure may be applied to the upper part of the side wall.

As described above, according to the present invention, a large machine is not required unlike the related art, so that even if the construction site is narrow, the shaft can be erected without any trouble, and the construction cost does not increase.

In the present invention, since the ground is excavated by the high-pressure water jet nozzle and the wing bit provided in the tip head and the mud is discharged by the spiral drill, strong hitting and driving are not generated, which adversely affects the area around the construction site. Not even.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

1 is a partially cutaway sectional view showing an embodiment, FIG. 2 is an explanatory view of the same process, and FIG. 3 is a partially cutaway perspective view of the concrete side wall.

4 and 5 are partially cutaway perspective views of a concrete side wall according to another embodiment.

In the present embodiment, a spiral drill (3) having a wing bit (1) at the tip and a hollow pipe (2) as a rotation axis, a high-pressure water injection nozzle (4), a water injection pipe (5), and high-pressure air injection are provided. A pipe (6) provided on a partition (8) inside a cylindrical tip head (7) is used. Then, the lower part of the tip head (7) is installed facing the ground, and a cylindrical concrete side wall (11) is loaded on the tip head (7) via a jack (9) and a reaction plate (10). Further, on the upper part of the concrete side wall (11), a ground anchor tension member (12), one end of which is fixed in the ground, is strongly grasped and pressure is applied by a jack (20) as a reaction force base.

In such a state, the ground (13) is excavated with the rotation of the wing bit (1) of the tip head (7) and the jet water from the high-pressure water jet nozzle (4), and the mud is removed with a spiral drill (3). It progresses, and according to progress, another concrete side wall (11) is sequentially added to the upper part of the concrete side wall (11), and a shaft (14) is formed to a predetermined depth. Then the hollow pipe (2) of the rotary shaft of the spiral drill (3)
A hardening agent such as concrete (15) is injected into the bottom of the shaft (14) via the inside. Next, the tip head (7) is withdrawn and the concrete (15) is hardened to complete the water-blocking shaft (16).

Note that the partition (8) of the tip head (7) in this embodiment.
The spiral drill (3) provided in the container is rotated by a rotary drive (21) inside the fixed pipe (17), and discharges the sludge toward the upper discharge port (18). I have. At this time, high-pressure air is injected from the high-pressure air injection pipe (6) to efficiently discharge sludge. Since the opening and closing pipe (22) is provided in the mud outlet (18), the valve (22) is closed when only air is discharged. When the spiral drill (3) is buried with mud, air does not escape. Also. The high-pressure water injection nozzle (4) is rotated by a nozzle rotation drive (19) to increase the excavation ability.

As described above, in the present embodiment, a large machine such as a steel sheet pile driving machine in the conventional construction method is not required, so that even if the construction site is narrow, the shaft can be constructed without any trouble. Also, the construction cost does not increase as in the conventional liner type shaft.

In this embodiment, the ground is excavated by the high-pressure main injection nozzle (4) and the wing bit (1) provided in the partition (8) of the tip head (7), and the mud is discharged by the spiral drill (3). There is no strong impact or vibration, and there is no adverse effect on the area around the construction site.

In this embodiment, the concrete side wall (11) has a cylindrical shape as shown in FIG. 3 and is successively added. However, as shown in FIG. You can also. It is also possible to use a rectangular one as shown in FIG.

(Effects of the Invention) According to the present invention, it is possible to provide a water-blocking shaft construction method capable of constructing a shaft in a narrow place or in an aquifer ground, at a low construction cost, and without adversely affecting the surrounding area of the construction site. it can.

[Brief description of the drawings]

1 is a partially cutaway sectional view showing an embodiment, FIG. 2 is an explanatory view of the same process, and FIG. 3 is a partially cutaway perspective view of the concrete side wall. 4 and 5 are partially cutaway perspective views of a concrete side wall according to another embodiment. (1): Wing bit, (2): hollow pipe (3): spiral drill, (4): high pressure water injection nozzle (5): water injection pipe, (6): high pressure air injection pipe (7): tip head, (8): Partition wall (9): Jack, (10): Reaction plate (11): Concrete sidewall (12): Ground anchor tensile material (13): Ground, (14): Vertical shaft (15): Concrete, ( 16): Waterproof shaft (17): Fixed pipe, (18): Drain outlet (19): Nozzle rotary drive, (20): Jack (21): Rotary drive, (22): Valve

Claims (4)

(57) [Claims] A spiral drill having a wing bit at a tip thereof and a hollow pipe as a rotating shaft, a high-pressure water injection nozzle,
Prepare a pipe with a water injection pipe and a high-pressure air injection pipe attached, place the lower end of the tip head into the ground, and install a cylindrical side wall with a predetermined length on the tip head. The ground is excavated with the rotation of the wing bit of the head and the injection water from the high-pressure water injection nozzle, and proceeds while muddy with the same spiral drill. After forming a shaft to the depth,
A water-blocking shaft construction method, in which a hardening agent is injected into the bottom of the vertical shaft through the hollow pipe of the rotary shaft of the spiral drill, and then the tip head is withdrawn and the hardening agent is hardened. . 2. The method for constructing a water-blocking shaft according to claim 1, wherein the ground anchor tension member having one end fixed to the ground is strongly gripped and pressure is applied to an upper portion of the side wall as a reaction force base. 3. The method for constructing a water-blocking shaft according to claim 1, wherein concrete is used as a hardening agent. 4. The method according to claim 1, wherein a side wall made of concrete or synthetic resin is used.