JPS6030837B2 - Vertical shaft excavation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shaft excavation method for excavating a shaft having upper and lower shafts connecting the two, and is used, for example, for excavating a glory hole in the construction of an underground power plant.

Conventionally, there are various methods for excavating vertical shafts for Glory Holes, including manual excavation, mechanical excavation using large-diameter boring machines, etc. However, when the excavation depth and excavation cross section become large, each method has limitations in terms of safety or mechanical performance. Construction becomes difficult.

Furthermore, in conventional shaft excavation in mines, shafts are excavated using blasting, and crater cut methods and the like are known. However, the conventional crater cut method does not excavate a large cross section at once, but when a large cross section needs to be excavated, the central part is punched out several times in advance, and then the outer circumference is further excavated. We are using a pay-as-you-go method. The present invention was developed in view of the above circumstances, and an object of the present invention is to provide a vertical shaft excavation method that allows excavation of large depths and large sections safely and quickly.

The following description will be given based on the illustrated embodiment.

Construction begins by drilling the required number of blast holes at the planned excavation location for shaft C.
to be drilled.

Next, after cleaning the blasting holes 1 from the upper hole A, the hole length is measured, and a required amount of explosives 3 is charged in the lower part of each blasting hole 1.
By detonating these explosives 3 at the same time, 1
Blasting of the stage is completed. Excavation of the shaft C is carried out by repeating the process from the cleaning of the blast hole 1 described above to blasting with the explosive 3 as one stage from the bottom of the shaft C to the top. FIG. 1 shows how a blast hole 1 is drilled, and the blast hole 1 is drilled from an upper hole A using a deep-hole drilling machine 2 such as a crawler drill.

At this time, it is desirable that the blast hole 1 has as little eccentricity as possible due to hole bending, and a stabilizer or the like may be used. Figure 2 shows the order of blasting: a, b, c,
Blasting is performed in the order of ..., i. The amount of excavation in one stage varies depending on the geology, amount of charge, method of charge, etc., but as you get used to the work, it becomes possible to excavate smoothly.

Further, the excavated debris is carried out from the lower shaft B. In addition, in the case of shaft C as shown in the figure, when the excavation cross section was about 8 mm, it was possible to excavate about 2.5 to 3 kites in one stage of blasting. Third
The figure shows the planar arrangement of the blast holes 1. Before each stage of blasting, the blast holes 1 are cleaned, the hole length is measured,
Perform accurate charging. Figure 4 shows the charging method, in which a seal plug 5 is placed at the tip of the blast hole 1, and sand 4 is placed above and below the explosive 3.
, 4'.

As the seal 5, a nylon bag filled with flaking powder, a small sandbag, or the like is used. Also, this sealed plug 5,
Explosive 3 can be attached by hanging it with thin nylon tape. According to Livingstone's crater theory, there are optimal amounts, lengths, and positions for forming good craters. The maximum depth of the resulting clay layer 7 is also approximately 1.5 mm (see Figure 5). In fact, even if the charge amount and charge length are increased beyond the design, the depth of the clay 7 does not change. However, it has been experienced that the pores expand beyond that point (see Figure 6). From this fact, the portion 8 where the hole diameter increases can be used as a burn hole. In other words, effective construction can be achieved by changing the number of stages of detonators, detonating the center of the core part first (the amount of charge will be slightly larger), and discharging the rest towards this direction. In addition, when shaft C excavated in this way is used as a glory hole in the construction of an underground power plant, the bench-cut shear from the upper part is pushed down with a bulldozer, etc., to the lower shaft level, and then carried out of the mine. As a result, a large underground space is formed.

This invention has the above-mentioned structure, and since drilling, charging, etc. are performed from the upper shaft, and the excavation does not require manual labor, construction is very safe. By increasing the amount of charge in the center of the hollowed-out part and using the enlarged diameter part created behind the blasting clay as a burn hole, the excavation cross section and depth can be increased, and construction can be carried out quickly. It will be done. Since the work is simple, as you get used to it, you can perform construction efficiently.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a sectional view showing how the blast holes are drilled, FIG. 2 is a sectional view showing the order of blasting, and FIG. 3 is the arrangement of the blast holes. A plan view, FIG. 4 is a cross-sectional view showing the charging method, and FIGS. 5 and 6 are cross-sectional views of the blasting of the blast hole in the cored portion. 1... Blasting hole, 2... Long hole drilling machine cover,
3...Explosives, 4,4'...Sand, 5...Tight plug, 6
...Doujo Line, 7...Clay Yu, 8...
Mine diameter portion, A... Upper pit, B... Lower pit, C... Vertical shaft, a, b, c, d, e, f, g
, h, i... 1st stage excavation part. Figure 1 Figure 2 Figure 3 Figure 5 Figure 4 Figure 6

Claims (1)

[Claims] 1 Required number of blast holes 1 from upper shaft A to shaft C excavation position
, measure the length of each blast hole 1 and charge the blast hole,
This is a shaft excavation method in which blasting is repeated sequentially from the lower part of the shaft C, and the excavated waste is carried out from the lower shaft B.The first part of the blast hole in the center of the hollowed out part where the number of stages of the detonator is changed and the amount of charge is slightly increased is used. A vertical shaft excavation method characterized in that a diameter enlarged part 8 produced in the depths of a crater 7 is used as a burn hole, and the other part of the blast hole surrounding this is blown toward the diameter enlarged part 8.