JPH02112600A - Excavating and constructing method of underground large-sized cavity - Google Patents

Abstract

PURPOSE:To excavate a large-sized cavity to an underground depth section in an unmanned manner by drilling a vertical heading from the ground surface, introducing an excavator and a concrete placer and successively cutting down the ground to a truncated conical shape by operation from the ground. CONSTITUTION:A vertical heading is excavated from the ground surface, and an excavator 11 and a concrete placer are introduced along a shaft bar 8 hung down into the heading. These devices are driven from the ground, a downward expanded truncated conical shelly ring ditch 12 is drilled, and concrete is filled and placed into the ditch 12 and a wall surface 2 is formed. The ground 14 corresponding to the height of the wall is cut down, and a truncated conical void is shaped. A truncated conical next stage void is formed to a section further lower than the ground 14 through the same method. A desired cavity 1 is constructed by repeating the process, and the whole surface of the concrete wall surface 2 is ground correctly and finished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a method for unmanned excavation and construction of a large cavity deep underground.

[Conventional technology l] A large cavern is created underground near a coastal power plant, surplus electricity at night is used to drive a compressor, and the generated compressed air is pumped into the large underground cavern and stored.

There is an idea to use this compressed air to generate electricity when electricity is needed during the day.

On the other hand, Suenaga has a plan to safely store the waste generated from nuclear power plants in large, deep underground cavities.

A large underground cavity is characterized by, for example, a cavity of 100,000 cubic meters or more created at a depth of several hundred meters or more underground, and a narrow hole connecting this cavity with the ground.

When creating a large cavity underground relatively shallow from the surface,
The cavity was filled with air at a pressure of 2 to 3 kg/am'', and humans and machines were placed inside the cave, and the humans worked within the air pressure.

However, this is limited to depths of up to 30 meters or less, and large cavities of the same type have not been created at deeper depths.

[Problem to be solved by the invention] The present invention is suitable for use deep underground, for example, at a depth of several hundred meters.

The present invention aims to provide a method for unmanned excavation of a large cavity with a diameter of 50 m and a room height, for example.

[Means for Solving the Problems 1] The present invention is a method for unmanned excavation and construction of a large underground cavity, in which a vertical shaft is excavated from the ground surface to the underground position where the large underground cavity is to be constructed, and a shaft is inserted into the vertical shaft. A rod is hung down, and an excavating device and a concrete placing device are introduced along this shaft rod, and these devices are driven from the ground to drill downward from the field foundation of the cavity to the position where the lower wall is to be formed. A widened truncated conical ring groove is excavated, concrete is poured into the ring groove to form a wall surface, and after the concrete has hardened, the ground is cut down to a level corresponding to the height of this concrete. Then, a truncated conical ring groove that spreads downward is excavated at the position where the lower wall is to be formed from the next stage of the ground. After repeating the above process and completing the desired cavity, the concrete wall is completely covered. It is characterized by a sanding finish.

[Function] The present invention provides a deep underground unmanned excavation method.

When creating a large volume of space underground as deep as possible from the ground surface,
Since passages with large cross-sections require extra excavation, it is better to have long and narrow passages connecting to the surface.

To prevent shell wall collapse, it is better to excavate under pressure that is balanced with ground pressure.

Although the shaft and the large underground cavern are concentric and have different diameters, this construction method produces excellent benefits when forming a hole with a circular horizontal cross section.

Furthermore, even if the internal volume of the large cavity is the same, the vertical cavity is easier to excavate and is more advantageous in terms of strength of the cavity.

When the shaft is formed, a long shaft is erected at the center of the shaft, and the lower end of this shaft is buried deeper than the planned bottom of the large underground cavity (this shaft is used for excavation, soil evacuation, and concrete placement equipment). It is a guide for lifting and lowering, and allows construction to proceed efficiently.

In the method of the present invention, multistage concrete rings cast in the shape of truncated conical shells are stacked diagonally with their ends in contact with each other to form a wall surface.

It is easy to excavate and construct, the amount removed for finishing can be reduced, and it is a reasonable ring that is resistant to earth pressure and compression, and is also satisfactory in terms of strength.

[Example 1] FIG. 6 shows the final cross-sectional shape of an example of a large underground cavity excavated and constructed according to the present invention. The large underground cavity 1 is an underground cavity with a diameter of 50 m and a height of about 100 m, and is provided underground at a depth of, for example, 500 m or less from the ground surface.

This large underground cavity 1 is lined with a concrete wall 2 and communicates with the ground surface through a vertical shaft guide shaft 3.

A seawater intake introduction pipe 5 is installed inside the shaft guiding pile 3, and a compressed air pipe 7 is also provided. The compressor 6 on the ground stores compressed air in a large underground cavity using, for example, nighttime electricity, and extracts it during the day to use it as an energy source.

The process of excavating and constructing such a large cavity 1 will be explained with reference to FIGS. 1 to 5.

First, a shaft guide shaft 3 is excavated from the ground surface, and a hole 9 into which a rod shaft 8 with a diameter of about 2 mφ or more is inserted is excavated in the large hollow excavated part l, and the shaft rod 8 is inserted into the hole 9 from the ground surface. This shaft rod 8 has functions such as transporting machines and materials for excavating and constructing large cavities, supporting an 8M machine for excavating and constructing, and serving as a discharge path for excavated rocks and the like. Along this axis rod 8, as shown in Fig. 1, the excavator El is lowered from the ground surface.
This excavator is expanded into a V-shape to excavate a truncated conical shell-shaped hole opening space 12. At this time, leave the rock in the center of the cavity.

It is best to excavate underwater while balancing water pressure and ground pressure (rock fragments produced by excavation are discharged to the surface by hydraulic transport using pumps.

Figure 1 shows the excavation process for the upper part of the large cavity, and Figure 2 shows the excavation process for the middle part of the large cavity. In FIG. 1, the arm 13 of the excavator may be short, but in FIG. 2, a long arm 13 is required.

Pressure oil for driving the excavator 11 is supplied through a hydraulic pipe 15 .

Next, concrete 17 is poured into this truncated conical shell-like space.

Figure 3 shows the concrete pouring process.

A nozzle 18 is provided at the tip of a concrete pouring arm 16 to pour concrete 17. Since concrete is underwater concrete, if it is necessary to cast it quietly to avoid stirring or separation, the mold and shape of concrete to be cast at one time will be determined based on geological conditions, rock type, etc.

Concrete is placed inside the shell-shaped excavated space, so no formwork is required.

After the concrete in the shape of a truncated cone hardens, the solidified concrete in the shape of a truncated cone undercuts the ground 14 in the large cavity as shown in Figure 4. Since the rock is supported by concrete, it is possible to dig into the inner surface of the rock without it collapsing.

Next, returning to FIG. 2, a truncated conical shell-shaped space 12 is excavated in the lower wall adjacent to the previously poured concrete.

There is no problem in supporting the previously poured concrete when excavating the inner surface of the concrete, as the rock at the bottom of the concrete provides sufficient support, even if integration with the wall is ignored.

For example, assuming that a concrete ring is supported by rock with shear force, the shear stress is 0.4 kg/
There is no problem at all at about "crn".

[Effect of the invention] According to the present invention, a truncated conical shell-shaped concrete wall is excavated,
It is possible to stably construct large cavities deep underground by unmanned excavation during construction, making it possible to utilize deep underground areas for new technologies such as energy storage and nuclear waste storage.

[Brief explanation of drawings]

Figures 1 to 4 are joint cross-sectional views explaining the process of excavating a large underground cavity according to the present invention, Figure 5 is a cross-sectional view of the completed large cavity, and Figure 6 is a cross-sectional view of the completed large cavity.
The figure is an explanatory diagram of the use of the completed large cavity. ■...Large underground cavity 2...Concrete wall 3...Vertical shaft guide shaft 5...Seawater introduction pipe 6...Compressor 7...
... Compressed air pipe 8 ... Rod shaft 9 ... Hole 10 ... Cone-shaped concrete wall 11 ... Excavator 14 ... Ground 13 ...
Arm 16... Concrete pouring Arm 17... Concrete pouring

Claims (1)

[Claims] 1. Excavating a vertical shaft from the ground surface to the underground location where a large underground cavity is to be constructed, suspending a shaft rod into the vertical shaft, and placing an excavator and concrete along the shaft rod. Introduce a device and drive the device from the ground to excavate a downwardly expanding truncated conical ring groove at the location where the lower wall surface is to be formed from the ground surface of the cavity, and fill the ring groove with concrete. The concrete is poured to form a wall surface, and after the concrete has hardened, the ground within the cavity corresponding to the height of the concrete is cut down, a truncated conical shell-shaped ring groove is excavated in the next stage of the ground, and the above process is repeated. , an unmanned method for excavating and constructing a large underground cavern characterized by finishing the concrete wall surface after completing the desired cavity.