JPS58176396A - Drilling construction of tunnel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a KII method for excavating foundation holes, etc. (hereinafter collectively referred to as tunnels, etc.) for the construction of Nanneru or dyed fabrics in bedrock.

As for the conventional excavation method, the blasting method using dynamite is widely used, but the vibration and noise of the explosion are extremely large, and the surrounding rocks are crushed irregularly, making it a bad environment in urban areas. In contrast, there is a risk of damaging the foundations of surrounding existing structures, and it is necessary to avoid damage to the surrounding bedrock, such as water conveyance tunnels for power plants and foundation construction of structures such as nuclear power plants. Conventional blasting methods are not suitable for excavating these holes.

Therefore, in this invention, a long slit is excavated in the horizontal direction in the middle part of the cross section to be excavated in a tunnel, etc., and one slit is made above and below this slit.
Injection holes T- are drilled in the bedrock at fixed positions using spaced pipes, these injection holes are filled with an expanding crushing agent, and the expansion value is increased by the volumetric expansion of the crushing agent. The rock tWl on the outside of the outer periphery of the wall is caused to generate cracks in the rock IlK.
By repeating the above operation f′F: on the resulting IjIi surface, the structure is expanded to approximately the desired shape Il[fl, and the noise at the time of crushing is reduced.
In addition, an excavation method that can crush only the necessary areas without causing damage to the surrounding rock has been obtained.

To explain this invention in detail, FIG. 1 shows the front view t1.
In addition, as shown in Figure 3, there is a vertical width of about 1 in the cross section of the tunnel (1) to be excavated.
0 number 1 is the number of slits) (2 m? Excavate in advance using a poling machine, etc. Then, the injection hole', 4 m)... is made approximately parallel to the wall surface (8) of this slit (2). (8) by a predetermined dimension (Ll'),
In addition, the injection holes (4a x 4m) are drilled into the rock (5) outside the upper and lower outer peripheries of the wall (8) at all intervals (existence). In addition, according to the experimental results, it is appropriate that the injection hole (4 m) has a diameter (dl' of several liters Q mtti, a depth ihl of several meters), and a dimension (Ll of several 100 W+a).

Then, a chemical crushing agent (6) (for example, a mixture of clinker made by mixing limestone and inorganic slack and firing at a high temperature, and an inorganic hydration inhibitor 'Ik811I') is mixed with water to form a mortar. If the expanding crushing agent (6) is filled into all the injection holes (41)..., the expanding crushing agent (6) will gradually expand compared to the solid, so it will be about 13 cm after filling.
In ~24 hours, cracks (7)... will occur in the rock (5) surrounding the injection hole (4), and these cracks (7)... will form walls (which are so-called free surfaces). 8], because the restraining force is small, it grows large and pierces the wall surface (8).
The surrounding area of 8) has been crushed, and the injection hole (4) where the expanding crushing agent (6) was injected...t@ new wall surface (
8a) will be formed. However, the original wall (
In the direction away from 3), the restraining force by the rock (5) is large, so the cracks (8) that occur are short.

Then, in winter, a new bedrock (
51, fill the injection holes (4b) in the 9th row completely with the expanding crushing agent (6), and similarly complete the new fI wall surface (31).
The surrounding sound on the wall (8a) is further shattered by the large hammer 9 (7)... which is generated towards the wall (8a). A tunnel of a desired shape (11) is enlarged and excavated by reversing the tunnel.

In the embodiments shown in Figures 1 to 4, the injection hole (
Perforation)...% (4b)...Either the upper or lower half of the slit (2), for example, the upper half, is drilled at once, and first, the hole is drilled in the hole that is close to the wall surface (8a) of the slit (2). The first row of injection holes (41)... is completely filled with the expanding crushing agent (6), then the second row of injection holes (4b)...K expanding crushing agent (6) is injected, and then the second row of injection holes (4b)... 8 rows of injection holes (4c)...
・Inject into the first row of injection holes (4m).
Cracks (7)... appeared on the new wall surface (8m).
) is formed and the expansion process of the expanding crushing agent (6) in the second injection hole (4b) begins.
I direction (8fi) K is set so that the crack (7) in the K direction can grow sufficiently large. Then, as shown in Fig. 4, the process of filling the workpiece with the expanding crushing agent (6) and the sequential crushing of the rock (5) due to the generation of abrasions was completed.
If ab) matches direction III of the desired tunnel (1), the above operation rF is performed for the next remaining lower rock [(6).
It can be cut down to 7A. Note that the order of this crushing is not limited to the above-mentioned one in which only the upper or lower parts are firstly crushed; KG may perform the above-mentioned expansion and crushing operation, and the injection holes (41) (4b) and
Of course, the holes .--. may also be made immediately before the filling operation. In the experimental example, andesite, Hanaokaite, 7IEI
This invented method has been successfully used to excavate hard rock such as R rock.

In the tunnel excavation method according to the present invention, a hole is bored approximately parallel to m- of the slit in the above-mentioned tunnel, and an expanding crushing agent t is injected into the injection hole.
- The structure is such that the zero expansion of this expanding crushing agent causes all the cracks to occur in the rock mass toward the 11th surface and crushes the rock mass outside the outer periphery of the wall surface. This device can efficiently crush the rock in the direction toward the wall and excavate a tunnel of the desired size, and it can be excavated without producing any crushing noise or vibration, so it does not damage the surrounding existing structures or the nearby rock. It is possible to excavate a tunnel in a desired shape without causing vibration and without fear of damaging the existing structure. In particular, in the method of the present invention, a free surface is formed by first opening a small slit t having a vertical width LO, so the method of Japanese Patent Application No. 11061/1987 proposed by the applicant earlier This method is advantageous in that the amount of work required is reduced compared to the method of forming a free hole II by completely excavating an advanced guide hole with a large cross section. Therefore, the tunnel excavation method of the present invention is particularly excellent for excavating tunnels in urban areas, power plants, etc., where the use of conventional blasting methods is unsuitable, and since large-sized machinery for excavation is not required, Various practical effects were obtained, including lower costs.

[Brief explanation of the drawing]

The figures show embodiments of this invention, including Fig. 1, Fig. 8,
FIG. 4 is a front view showing an intermediate step in the process, FIG. 2 is a sectional view taken along the line of Mu in FIG. 1, and FIGS. 5 and 6 are front views showing an intermediate step in another embodiment. Code explanation (1)...Tunnel (2)...
・Slit (81 (8aX8b) --=Wall surface (4m)
(4b) (4e) - = Injection hole (51... Rock mass (6)... Expanding crushing agent +71 (8
1・−・・Crack (g・・・・Dimensions (9)・−・・−・
Interval (dl...diameter tkl...
...Depth 1 Agent Patent Attorney Takayoshi Hayashi j Figure 1 Figure 3 Figure 4!

Claims (1)

[Claims] A long slit in the horizontal direction is pre-drilled in the middle of the cross section to be excavated for a tunnel, etc., and above and below this slit,
Injection holes are drilled in the rock at predetermined positions from the wall of the slit, and these injection holes are filled with an expanding crushing agent, and the volumetric expansion of this expanding crushing agent causes the rock to flow toward the wall. A crack is generated and the rock outside the outer periphery of the Il surface [
A method for excavating tunnels, etc., in which the above-mentioned operation is repeated for the new l1dliK created by this, thereby expanding the wall surface to roughly the desired shape.