JPH0313686A - Excavating method for vertical shaft - Google Patents

Abstract

PURPOSE:To excavate a safe vertical shaft at a low cost by drilling a pilot hole with the diameter smaller than that of the vertical shaft is advance, and using a fully rotary all casing excavator provided with excavating bits on the inclined edge section of an inverse triangular blade. CONSTITUTION:A pilot hole 9 with the diameter smaller than that of a vertical shaft is penetrated and drilled in advance at the center of the excavation area of a vertical shaft 10. Excavating bits are provided on the inclined edge section of an inverse triangular blade 4 fixed on the inside of the head pipe of a casing tube 3, and the casing tube 3 is guided to the tip of the inverse triangular blade 4 via the pilot hole 9. The vertical shaft 10 is excavated while excavation chips are dropped into the underground space or a tunnel 8 through the pilot hole 9. The vertical shaft 10 is safely and efficiently drilled, excavation chips can be carried out, and the work efficiency can be improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a method for excavating a shaft that serves as a vent or exhaust port for a tunnel, an underground space for petroleum storage, an underground space for a power plant, etc., or a connecting passageway with the surface. Regarding.

[Conventional technology]

Methods for excavating vertical shafts as mentioned above include - In addition to drilling with a down-the-hole drill (the diameter of the hole that can be drilled using this method is approximately 1 mφ), drilling is possible from underground to the surface by rotating a roller crushing bit called a raise bore. There is a construction method that involves pulling it up towards the ground.

Furthermore, when excavating large diameter shafts, a manual method called the cut-up method, which is carried out by hand and blasting rocks, is often used. In this method, a lift is suspended by passing a wire through a small-diameter hole drilled in advance from the ground surface, and a person rides on the lift to load gunpowder into the hole.Then, the operations of evacuation and detonation are repeated. While working, the shaft is cut up from underground to the surface.

In addition, there is a method called the Alimakue method, and a recently developed all-casing method in which a hole is dug from the ground surface using a fully rotating all-casing drilling machine.

[Problem to be solved by the invention]

Among the above-mentioned construction methods, the construction methods other than the all-casing construction method have limitations on large area (hole diameter that can be drilled) and safety problems. In particular, the cut-up method is highly dangerous due to the use of explosives, as well as the possibility of rocks falling when drilling the gunpowder loading holes.

Therefore, there are many products with a large rotational force and pushing force, and a diameter of 2.
A construction method using an all-casing machine that can drill holes over 50 meters deep is attracting attention.

However, with this all-casing construction method, the stratum that remains as the core inside the casing tube is grabbed using a crane and a hammer club, etc.
It is extremely impossible to drill a deep hole exceeding 100 m.

Therefore, the present invention aims to provide a method for excavating a vertical shaft inexpensively and safely by utilizing the casing method.

[Means to solve the problem]

In the method of the present invention, a pilot hole having a diameter smaller than the diameter of the shaft is previously drilled in the center of the excavation area of the shaft.

Next, a drilling bit is provided at the tip of the leading tube of the casing tube and the inclined edge of one or more inverted triangular wings fixed inside the leading tube, and a profiling bit is further inserted into the pilot hole at the tip of the inverted triangular wing. Using a fully rotating all-casing excavator equipped with a drilling head with a guide, the vertical shaft is constructed while guiding the casing tube through the pilot hole and dropping the excavated waste through the pilot hole into the underground space or tunnel. dig.

[Operation] A pilot hole that reaches the target space can be drilled using a down-the-hole drill, a poling machine, or the like.

According to this invention, the pilot hole plays the role of guiding the casing tube during the next hole-drilling operation and sequentially dropping and removing the excavated waste into the lower space, making it possible to carry out the hole-drilling operation continuously. , the pilot hole is
In addition to making drilling easier during hole expansion and further increasing work efficiency,
It also has a positive effect on the life of the bit at the tip of the drilling head.

In other words, brittle materials such as rocks have a large compressive strength, but a weak tensile strength and are prone to cracking when penetrating force is applied near the free end. As shown in Figure 1, the cutting force of the bit 1 at the tip of the casing tube increases in the input direction.
The core inside the tube becomes susceptible to cracks and collapses.

Bit 2, which is attached to the inverted triangular wing, cuts into the core part in order from the one closest to pilot hole 9, and the cutting force of 2 acts in the direction B, so the rock that is destroyed becomes a piece. It will fall into the pilot hole one after another, so 2
Next cutting will be reduced. Therefore, the excavation efficiency is much better than pure cutting and pulverization.

Further, for the above reason, the bit 2 can cut the core with a particularly weak force, so the load is small and wear and tear is small.

The above actions and effects reduce drilling costs.

In addition, work safety is ensured by applying the casing construction method.

〔Example〕

An example of the method of the present invention will be explained based on FIGS. 1 and 2.

First, a pilot hole to be excavated from the surface of the earth toward an underground tunnel or the like is excavated using a down-the-hole hammer, an earth auger, a boring machine, or the like. FIG. 2 shows an example of this. In the figure, 6 indicates a dowser hole hammer, 7 indicates a down-the-hole drilling machine, 8 indicates an underground tunnel, and 9 indicates a pilot hole.

The diameter of the hole 9 is determined in consideration of the diameter of the shaft 10 so as to maintain good discharge of excavated debris. If shaft 10 is 2mφ, 9
The diameter needs to be approximately 500 mm.

A down-the-hole drill can drill a hole of approximately 200 to 600 mφ, so in the above case, it will be sufficient.

Now, if you bend the pilot hole one time like this,
We move on to the hole drilling work using a fully rotating all casing machine.

This all-casing machine uses a specially designed drilling head. As shown in FIGS. 1 and 3, the excavation head has bits 1 arranged in a staggered manner in the circumferential direction at the tip of the leading end of the casing tube 3.

Furthermore, an inverted triangle 14 is provided inside the leading tube at a position crossing the center of the tube. Although it is sufficient to have one wing 4, the figure shows two wings mounted in a criss-cross pattern. Then, a bit 2 is attached to the inclined edge of each blade 4 to excavate the core portion left uncut by the bit 1. As shown in the figure, it is preferable for this bit 2 to protrude in the digging direction.If it is oriented perpendicular to the slanted edge of the blade 4, the digging speed will not increase and the heat generation of the pit will increase. .

This has also been confirmed through small-scale simulation experiments in which concrete blocks were used as bedrock.

In addition, a tracing guide 5 is provided at the tip of the inverted triangular wing 4 to guide movement of the casing tube through the pilot hole 9. The guide 5 may be formed of either a flat plate or a cylinder as long as it does not hinder the falling of excavated debris by the bit 2. Also, the guide 5 may have a structure in which rollers are scattered around the outer periphery to reduce friction with the bit 9. It's okay.

If a hole-drilling operation is carried out using a fully rotating all-casing machine having such a drilling head, using the pilot hole 8 as a leading hole, a shaft 10 of a desired diameter can be drilled safely and efficiently.

Reference numeral 11 in FIG. 1 is a transport vehicle for excavated debris generated during hole drilling, and since it can directly receive and carry out fallen debris, work efficiency is improved in this aspect as well.

〔effect〕

As described above, according to the method of the present invention, while guiding the casing tube with the previously drilled pilot hole and sequentially discharging excavated waste, the pilot hole is used as the free surface, and this free surface is the most effective. A shaft of the desired diameter is drilled from the surface side using a drilling head with a structure that is used in
And there is no need for a crane to raise and lower it.

(2) Since the excavated soil is continuously discharged, there is less downtime during work.

(3) Brittle fracture of the rock tends to occur during hole expansion (excavation speed increases).

(4) Bit wear and chipping are reduced due to brittle fracture of the rock and reduction in secondary cutting.

As a result, the construction period is shortened and construction costs are reduced.

In addition, since the all-casing machine method is applied, work safety is high.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the hole-drilling process according to the method of the present invention, FIG. 2 is a cross-sectional view of the pilot hole drilling process performed in advance, and FIG. 3 is a front view of the drilling head of FIG. 1. . 1.2... Bit 3... Casing tube, 4... Inverted triangular wing, 6... Down the hole hammer, 7...
Down-the-hole drilling machine, 8...Underground tunnel, 9...Pilot hole, 10...
...Shaft, 11...Transportation vehicle.

Claims (1)

[Claims] (1) In the method of penetrating a shaft from the ground surface into an existing underground space or tunnel, a pilot hole with a diameter smaller than the diameter of the shaft is drilled in advance in the center of the excavation area of the shaft, and then the leading pipe of the casing tube is drilled. A drilling head having a structure having a drilling bit on the inclined edge of one or more inverted triangular wings fixed to the tip and inside of the leading tube, and further having a profiling guide inserted into the pilot hole at the tip of the inverted triangular wing. The shaft is excavated using a fully rotating all-casing excavator equipped with the shaft while leading the casing tube through the pilot hole and dropping excavated waste into the underground space or tunnel through the pilot hole. Drilling method.