JP4459966B2 - Stone mining method - Google Patents

Description

The present invention relates to a stone mining method, and more particularly, to a method of quarrying stone from the remaining pillar without impairing the strength of ground support of the remaining pillar formed by the remaining pillar type mining method.

Conventionally, the Oya stone quarrying work employs the remaining pillar type mining method from the standpoint of preventing ground subsidence and ground collapse and improving the stability of the ground. However, the underground cavities formed by quarrying work lose stability over time due to natural disasters such as earthquakes and the vibrations of heavy-duty vehicles that frequently travel on the surface of the earth, often causing various types of ground subsidence and ground subsidence. Causing an accident. For this reason, various filling methods for filling the underground cavity have been proposed as countermeasures. However, the underground cavity is filled with groundwater, and the cross-sectional dimension of the remaining pillar is as large as 10 m square. Because the amount of Oya stone remains, the method of refilling the underground cavities is not appropriate, and it will be stored without effectively using the precious underground resource of Oya stone.

This invention makes it a subject to quarry stone material from the said remaining pillar, without impairing the ground support strength of the remaining pillar formed with the remaining pillar type mining method.

Another object of the present invention is to provide a stone quarrying method that can contribute to environmental conservation by utilizing a space formed after quarrying for an industrial waste disposal site or the like.

In order to solve the problem, the quarrying method adopted by the present invention includes a groove for forming a reinforcing wall extending from the top located above the remaining column in the underground mine formed by the remaining column type mining method into the remaining column. A step of forming, a step of forming a residual pillar reinforcing wall in the groove, and a step of digging an area surrounded by the residual pillar reinforcing wall and quarrying from the residual pillar, is there.

In one aspect, the step of forming the groove includes a step of determining a mining area on a top board located above the remaining pillar, and a step of forming the groove so as to surround the mining area. . The mining area is set so as to be within the cross-sectional shape of the remaining pillar. The groove portion can be formed by drilling holes continuously with a boring machine along the periphery of the mining region from the top surface of the roof toward the remaining pillar. In one aspect, the groove reaches the lower end of the remaining pillar, or further reaches the floor of the underground pit, and in another aspect, reaches the middle part in the height direction of the remaining pillar. The groove portion is a continuous groove portion (a self-closed groove portion or an endless groove portion), and in one preferred embodiment, the groove portion is formed in a cylindrical shape.

In one preferred embodiment, the remaining column reinforcing wall is a reinforced concrete wall, and the step of forming the remaining column reinforcing wall includes a step of building a reinforcing bar cage in the groove portion and a concrete placement in the groove portion in which the reinforcing bar cage is built. The process of performing.

In one aspect, the process of removing the topsoil laminated | stacked on the top is provided as a pre-process of the process of forming the said groove part. This is a step of excavating the required surface area of the top soil located above the remaining pillars to remove the remaining soil and exposing the top located above the remaining pillars. In one embodiment, a rectangular outer frame that defines a stone excavation region is formed of concrete on the upper surface region of the exposed roof. The outer frame also has a function as a retaining wall.

Since the remaining pillar reinforcement wall is formed on the outer periphery of the remaining pillar mining area, the quarrying work can be stably performed without damaging the ground support strength of the remaining pillar, which has been difficult from the viewpoint of safety. It is possible to quarry from the remaining pillars, which can contribute to the effective use of underground resources. In addition, the space formed after quarrying can be used as a dump site for industrial waste.

The Oya stone underground mine formed by the remaining pillar type mining method will be described. FIG. 1 is a schematic view of an abandoned mine of Otani stone mined in the past, and is a large underground cavity 1 at present. There are many cases where underground water is accumulated in the underground cavity 1. In the underground cavity 1, a plurality of pillar portions are left as the remaining pillars 2, and the remaining pillars 2 support the ground, that is, the top 3 constituting the ceiling portion of the underground cavity 1 and the top soil 4 thereon. is doing. In many cases, not only the remaining pillar 2 but also the lower part of the top 3 constituting the ceiling part of the underground cavity 1 and the floor part 5 of the underground cavity 1 are composed of Oya stone layers. The purpose of Fig. 1 is to explain the structure of the Oya stone underground mine formed by the remaining pillar type mining method, and the relative thickness of the roof 3 and topsoil 4 and the dimensions (height and cross-sectional dimensions) of the remaining pillar 2 The typical dimensions do not necessarily reflect the actual dimensions of the underground cavity. Although the dimensions of the Oyaishi underground mine differ from site to site, for example, the thickness of the topsoil 4 layer is about 10 m, the top 3 layer thickness is about 30 m, and the remaining pillar 2 The dimensions are about 30 m in height, and the cross-sectional dimensions are 10 to 20 m square.

FIG. 2 shows a state in which one remaining pillar 2 is selected in FIG. 1 and the top soil 4 above the selected remaining pillar 2 is removed from the required surface area. In one embodiment, the required surface area is an area exceeding the cross-sectional dimension of the remaining pillar 2 selected in plan view. A required outer area of the topsoil 4 located above the remaining pillar 2 in the underground mine is excavated to remove the residual soil, and a rectangular outer frame 6 that divides a stone excavation area on the exposed upper surface area of the roof 3 is provided. Form with concrete.

The mining region S is set so as to be located in the outer frame 6 and directly above the remaining pillar 2 and to be within the cross-sectional dimension of the remaining pillar 2. In the example shown in FIGS. 9 and 10, the cross-sectional dimension of the remaining pillar 2 is 20 m square, and a circular area having a diameter of 18 m is set so as to surround the mining area set in the cross-sectional dimension of the remaining pillar 2. A remaining column reinforcing wall 7 having a thickness of about 0.8 to 1 m is formed along the circumference. Further, the thickness of the topsoil 4 is 12 m, the thickness of the top 3 is 34 m, and the height of the remaining pillar 2 is 30 m.

A method for forming the remaining column reinforcing wall 7 will be described. For the construction of a reinforcing wall, it is located in the outer frame 6 and is continuously drilled along the circumference of the circular region with a boring machine from the upper surface of the roof 3 toward the remaining pillar 2. The cylindrical groove portion 8 is formed (FIGS. 3 and 6). In one aspect, the groove portion 8 reaches the lower end of the remaining pillar, or further reaches the inside of the underground pit floor (FIG. 3), and in another aspect, reaches the midway portion in the height direction of the remaining pillar. (Fig. 6). Next, a rebar cage (not shown) is built in the groove 8 and a concrete placement is performed to form a cylindrical remaining pillar reinforcing wall 7 (FIGS. 4 and 7). The method for forming the remaining column reinforcing wall 7 can be performed by using a known method. For example, the reinforcing wall can be formed by using a construction method similar to the construction method of the continuous underground wall. The rebar cage is well known to those skilled in the art. For example, the rebar cage is formed by arranging a required number of rebars in the weft direction and knitting a cylindrical structure, and this is formed by a hanging means such as a crane to form the groove portion 8. Build in. Concrete placement is also well known to those skilled in the art. For example, in a concrete mixer, a material obtained by kneading cement, sand, gravel, water, or the like in an appropriate ratio is pressed into the groove 8 and dried, and then reinforced concrete is used. The remaining pillar reinforcing wall 7 is configured. The upper end of the remaining column reinforcing wall 7 reaches the surface of the top 3 of the upper layer of the remaining column 2. The remaining pillar reinforcing wall 7 and the outer frame 6 are integrated by placing concrete.

Open pit mining is performed in the mining region S surrounded by the cylindrical residual pillar reinforcing wall 7 and quarrying is performed from the residual pillar 2 (FIGS. 5 and 8). Open pit mining is a quarrying method that quarries in a stepwise manner from the surface. Since the surface mining itself for collecting stone materials is well known to those skilled in the art, detailed description thereof is omitted. The quarrying method of the present invention is mainly intended for quarrying from the remaining pillar 2, but when there is a useful stone in the top 3, the stone can also be collected.

While the remaining pillars 2 are selected one by one, quarrying is performed from the remaining pillars 2, but the reinforced concrete residual pillar reinforcement wall 7 is formed on the outer periphery of the remaining pillar 2 mining area. The quarrying operation can be performed in a stable state without damaging the quarrying, and the quarrying from the remaining pillars, which has been considered difficult from the viewpoint of safety, can be performed, thereby contributing to the effective use of underground resources. Moreover, since the invasion into the groundwater mining area filled in the underground cavity can be prevented by the reinforcing wall 7, the quarrying work can be performed efficiently.

The space S1 after the quarrying is a huge cylindrical concave portion having an opening on the upper side, the side wall of the concave portion is made of the reinforcing wall 7, and the bottom of the concave portion is made of Oya stone. Such huge recesses have a wide variety of uses. For example, waste such as molten slag can be embedded in the huge recess.

It can be used to quarry stone from the remaining pillars formed by the remaining pillar type mining method. Moreover, the space obtained after mining can be used effectively.

It is a schematic diagram of the abandoned mine of Oya stone mined in the past. In FIG. 1, it is a figure which shows the state which removed the top soil above the selected one remaining pillar. It is a figure which shows the state which formed the groove part which reaches to the lower end of a remaining pillar from the state of FIG. It is a figure which shows the state which formed the reinforcement wall in the groove part of FIG. It is a figure which shows the state after quarrying from the area | region enclosed by the reinforcement wall of FIG. It is a figure which shows the state which formed the groove part which reaches the middle part of a remaining pillar from the state of FIG. It is a figure which shows the state which formed the reinforcement wall in the groove part of FIG. It is a figure which shows the state after quarrying from the area | region enclosed by the reinforcement wall of FIG. FIG. 5 is a plan view of a selected remaining pillar portion in FIG. 4. FIG. 10 is a perspective view showing FIG. 9 in a longitudinal section.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Underground cavity 2 Remaining pillar 3 Top plate 4 Topsoil 5 Floor part 6 Outer frame 7 Reinforcement wall 8 Groove S for reinforcement wall structure Mining area

Claims (4)

Forming a reinforcing wall-forming groove extending from the top located above the remaining pillar in the underground mine formed by the remaining pillar-type mining method;
Forming a remaining column reinforcing wall in the groove,
A step of digging an area surrounded by the remaining pillar reinforcement wall and quarrying from the remaining pillar;
Mining method of stone material equipped with. The step of forming the groove includes
Determining a mining area on a roof located above the remaining pillars;
Forming a groove so as to surround the mining region;
The method for mining a stone according to claim 1, comprising: The step of forming the remaining pillar reinforcing wall includes
A step of building a rebar cage in the groove,
A process of placing concrete in a groove part in which a reinforcing steel cage is built, and
The method for mining a stone according to any one of claims 1 and 2. The stone mining method according to any one of claims 1 to 3, further comprising a step of removing the topsoil laminated on the top as a pre-step of the step of forming the groove.

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