JP2787180B2 - Stabilization of collapsed rock mass during tunnel excavation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for stably crushing a collapsed rock mass having a large number of cracks and voids therein by blasting during tunnel excavation.

[0002]

2. Description of the Related Art When a tunnel is excavated in a rock mass, a large number of blast holes having a predetermined depth are drilled in the face of the tunnel in the direction of tunnel excavation, and then explosives are charged in these blast holes and then exploded. By crushing the bedrock at a predetermined depth from the facet by removing it, and excluding it, it is possible to excavate to a predetermined length by repeating the drilling of blast holes, loading of explosives, and blasting in the same manner as above. In the case of collapsible rocks in which the rocks have cracks or sand-like crushed zones due to ground deformation, etc., the crushed bands flow out to the face side along with the spring water in the rocks through the cracks. There is a possibility that the bedrock of the part may collapse. Therefore, conventionally, the face of the face has been stabilized by spraying concrete on the face or by injecting an injection hole into the face and injecting and hardening a chemical solution into the cracked portion through the injection hole.

[0003]

However, by spraying concrete on the face as in the former case, it is not possible to stabilize even the cracked portion inside the rock to be excavated. There is a risk that the crushing zone may flow out through the slab, and furthermore, there is a problem that the concrete spraying operation requires remarkable labor. In addition, in order to form a chemical liquid injection hole as in the latter case, additional injection equipment and the like are required, and in addition to the blast hole, an injection hole drilling operation is required, thereby lowering the tunnel excavation efficiency. There is a problem. An object of the present invention is to provide a method for stabilizing a collapsed rock mass which can completely solve such a problem.

[0004]

Means for Solving the Problems In order to achieve the above object, the stabilization method of the collapsed rock mass at the time of tunnel excavation according to the present invention is characterized in that the method is applied to the tunnel face including the collapsible rock mass vertically and horizontally.
After the curable material is filled in the tip of each blast hole drilled at predetermined intervals in the direction of the length of the tunnel in the direction , the explosive is loaded into each of the blast holes following the curable material. by later blow the explosives, the curable material
Injection by blast pressure into the collapsed rock with cracks around the tip of each blast hole to form a rock stabilization layer,
After the formation of the rock stabilization layer, the explosive
To load and explode gunpowder with greater blasting power
Rock mass between the face stabilization layer and tunnel face
Crushing .

[0005] In the method for stabilizing the collapsed rock mass, the invention according to claim 2 is characterized in that:
Low explosive and high explosive explosives in each blast hole
Are loaded one after another , and the blast
Inject hardening material into collapsible rock to form rock stabilization layer
The bedrock by blasting a large explosive at the same time as the bombing forces formed
The rock portion between the stabilizing layer and the tunnel face is crushed, and the invention according to claim 3 has a small blasting force in each of the blast holes formed in the face.
A gunpowder and a gunpowder having a large blasting power are sequentially loaded, and a hardened material is injected into the collapsible rock by the blasting of the gunpowder having a small blasting power and hardened to form a rock stabilization layer.
Then, immediately after, the explosive with high blasting force on the rear side is blasted to crush the rock face on the face side from the rock stabilization layer .

[0006]

After the curable material and the explosive are sequentially loaded into the blast hole, the explosive is blasted. When the blast pressure of the explosive causes the curable material to explode, cracks in the surrounding disintegrable rock or voids in the crush zone. And is solidified in these cracks and voids to prevent spring water in the rock from entering the blast holes. Blast holes are drilled at predetermined intervals in the tunnel face,
Therefore, when the curable material loaded at the tip of all the blast holes was injected into the cracks and crush zones in the surrounding rock due to the blast pressure of the explosive, filled and hardened, the curable material was loaded. A rock stabilization layer made of a curable material is formed in the rock around the tip of each blast hole.

The rock stabilization layer is provided in parallel with the tunnel face, and a rock portion between the rock stabilization layer and the face is formed.
When crushed by the blasting of the explosive having a greater blasting power than the above explosive loaded in each blast hole, the rock stabilization layer becomes a face portion to be excavated next, and the rock stabilization layer causes the rock face to be excavated. The leakage of spring water to the river is prevented. On this occasion,
Injection of curable material into the disintegrable rock due to the explosion of explosives
Crushing of the rock face on the face side from the stabilization layer may be performed at the same time, and after injection of the curable material into the collapsible rock,
Immediately crush the rock face on the face side from the rock stabilization layer
You may.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the drawings. First, a suitable drilling tool is used on a face 2 of a collapsible rock mass on which a tunnel 1 is to be excavated. A blast hole 3 is drilled. The blast holes 3 are drilled in the face face at predetermined intervals in the vertical and horizontal directions, and the drilling length (depth)
Is a normal blast hole, that is, 0.5 to 1.0 m longer than the length of the charging hole used only for blasting, and as shown in FIG. 3a, a portion corresponding to the length of a normal blast hole is formed in the explosive charging hole portion 3b.

Next, as shown in FIG. 4, a hardening material 4 such as cement alone or a mixture of cement and quick-setting agent is added to a hardening material loading hole 3a of each of the blast holes 3, and an appropriate amount of explosive. 5 are sequentially loaded, a stopper 6 is inserted and pressed against the rear end face of the explosive 5, and the explosive 5 is sealed in the blast hole 3 by the stopper 6.

The curable material 4 is filled in a cylindrical paper bag or mesh bag 7 as shown in FIG. 5 to facilitate loading into the blast hole 3, and is immersed in water immediately before use. After immersing the curable material 4 in the bag to immerse the water therein, it is inserted up to the loading hole 3a. The curable material 4 includes a mixture of a powdery hardening material such as cement and a powdery quick-setting material. On the other hand, as the explosive 5 to be loaded after the curable material 4, an explosive with a slow blast speed, that is, a small blasting force is used. Further, the hardening material 4 does not necessarily need to be mixed with a quick-setting material, but may be only cement, or may be other materials.

After the curable material 4 and the explosive 5 are loaded into a predetermined portion of each of the blast holes 3 and sealed as described above, the explosive 5 is blasted through a conducting wire 8 connected to the explosive 5. Then, the curable material 4 is injected by a blast pressure of the explosive 5 into a crack 9 or a crush zone 10 formed in the collapsible rock around the hole 3a in which the curable material 4 is loaded. At this time, since the explosive uses an explosive whose explosion speed is slower than that of the explosive for rock blasting, the pressurized state of the curable material 4 continues for a long time, and the curable material 4 communicates with the loading hole 3a in an intersecting manner. The cracks 9 and the crush zone 10 are sufficiently injected deeply.

Further, the curable material 4 loaded in the tip hole 3a of the blast hole 3 is injected into the crack 9 and the space of the crushing zone 10 by the blast pressure of the explosive 5 as described above, and is adjacent thereto. The gap is closed by the injected hardening material 4 in the collapsible rock portion between the hardening material loading holes 3a, 3a, and is formed in the rock stabilizing layer 11 as shown in FIG. Curable material 4
Is completely cured after a certain period of time.

After the hardening material 4 is injected from the facet into the collapsible rock portion except for the rock portion 12 corresponding to the explosive charging hole portion 3b of the blast hole 3, the explosive charging hole portion 3b of each blast hole 3 is immediately obtained. Explosive for explosive rock destruction with high destructive power inside
6 is charged as shown in FIG. 6 and the blast hole 3 is sealed with the stopper 14. After the explosive 13 is blasted through the conducting wire 15, the collapsible rock portion 12 between the face face and the rock stabilization layer 11 is formed.
Is crushed to the rock stabilization layer 11 and the rock stabilization layer 11
Becomes the next tunnel excavation face, and the rock stabilization layer 11 is in a state in which spring water from the inside of the collapsible rock to the face side and collapse of the rock are prevented. The crushed rock is removed through the tunnel.

Next, the curable material loading hole 3a and the explosive loading hole 3b are formed from the face in the tunnel excavation direction in the same manner as described above.
After a plurality of blast holes 3 composed of the following are drilled, and the curable material 4 is loaded into the curable material loading hole 3a on the tip side of the blast hole 3, the explosive 5 with a slow blast speed is inserted and the stopper 6 is used. The intermediate portion of the blast hole 3 is sealed, and the explosive 5 is blasted to inject the curable material 4 into the rock crack 9 and the crush zone 10 around the loading hole 3a to form the rock stabilization layer 11. Subsequently, the explosive 13 having a high blasting power and explosive speed is loaded into the explosive loading hole 3b, and plugged.
After sealing with 14, the explosive 13 is blasted to crush the collapsible rock portion 12 between the rock face 2 and the rock stabilization layer 11, and this work process is repeated to excavate a tunnel in the rock mass. It is.

In the above embodiment, first, the curable material 4 is blasted with the explosive 5 to form a crack 9 or a crush zone in the collapsible bedrock.
After injection into 10, the explosive loading hole 3b in the middle of the blast hole 3
The explosive 13 with a large explosion speed was loaded therein and the explosive 13 was blasted to break the rock, but as shown in FIG.
The curable material 4 is previously inserted into the curable material loading hole 3a of the blast hole 3.
After loading, the slow explosive 5 and the fast explosive 13
Are sequentially loaded into the explosive loading hole 3b, and after plugging 16,
By blasting the explosives 5 and 13, a rock crack 9 and a crush zone 10 around the loading hole 3 a due to the blasting of the explosive 5 are obtained.
Injection of the curable material 4 into the inside and crushing of the collapsible bedrock portion 12 by blasting of the explosive 13 may be performed.

In this case, the explosive 5 and the explosive 13 are simultaneously blasted, and the curable material 4 is injected into the collapsible rock by the blast of the explosive 5, and at the same time, the hardened material-injected rock, that is, the rock stabilization layer 11 The rock part on the face side may be crushed by blasting the explosive 13, and the curable material 4 may be injected into the collapsible rock by blasting the explosive 5, and immediately the explosive on the rear side may be crushed.
13 may be blasted to break the rock face on the face side.
Depending on the quality of the rock, the explosive having a high explosive speed may be exploded without using the explosive having a slow explosive speed, and the rock may be crushed simultaneously with the injection of the hardening material. Further, the curable material may be directly inserted into the blast hole 3 without being put in the bag.

[0017]

As described above, according to the method of stabilizing the collapsed rock mass at the time of tunnel excavation according to the present invention, each blast hole drilled at predetermined intervals in the vertical and horizontal directions in the tunnel face including the collapsible rock mass. After filling the curable material within the distal end of the explosive loaded into the blasting hole subsequent to curable material, after accordingly, by blasting the explosives, fracture disintegration rock mass
Since the curable material is injected without crushing into the collapsible rock having cracks around the tip of each blast hole by blast pressure, cracks around the tip of the blast hole and The curable material can be reliably injected and hardened into the collapsible rock portion having the crush zone, and the injection can form a rock stabilization layer at an appropriate depth from the face .

[0018] Furthermore, is the method of loading the explosive with a large blasting force into the middle part of the blast hole and blasting it to crush the rock part between the rock stabilizing layer and the face .
Et al, become the working face portion to be next drilling rock stabilization layer by the crushing, therefore, the rock in the該岩Release stabilizing layer
To prevent spring water and blasting belt from flowing to the face side
As well as eliminating rock collapse at the face
A blast hole is drilled from the face again , and the injection of the curable material into the collapsible rock around the blast hole tip, the hardening treatment, and the crushing of the rock at the face portion are repeated as described above. By doing so, it is possible to excavate a tunnel smoothly and efficiently while preventing rock collapse.

[Brief description of the drawings]

FIG. 1 is a simplified longitudinal side view of a tunnel face portion having a blast hole,

FIG. 2 is a front view thereof,

FIG. 3 is a simplified sectional view of a blast hole,

FIG. 4 is a longitudinal sectional side view showing a state where a curable material and an explosive are loaded;

FIG. 5 is a simplified cross-sectional view of a bag filled with a curable material,

FIG. 6 is a longitudinal sectional side view showing a state in which a powder for crushing rock is loaded;

FIG. 7 is a vertical sectional side view for explaining another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tunnel 2 Face 3 Blast hole 3a Hardening material loading hole 3b Explosive loading hole 4 Hardening material 5 Slow explosive powder 11 Rock stabilization layer 13 High explosive powder

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiko Tanaka 2-2-2 Matsuzaki-cho, Abeno-ku, Osaka-shi Okumura Gumi Co., Ltd. (56) References JP 3-45319 (JP, B2) (58) Survey Field (Int.Cl. ⁶ , DB name) F42D 3/04 E21D 9/00 F42D 1/00

Claims (3)

(57) [Claims] 1. The vertical and horizontal directions of the tunnel face including collapsed rock
After the curable material is filled in the tip of each blast hole drilled at predetermined intervals in the direction of the length of the tunnel in the direction , the explosive is loaded into each of the blast holes following the curable material. by later blow the explosives, the curable material
Injection by blast pressure into the collapsed rock with cracks around the tip of each blast hole to form a rock stabilization layer,
After the formation of the rock stabilization layer, the explosive
To load and explode gunpowder with greater blasting power
Rock mass between the face stabilization layer and tunnel face
A method for stabilizing collapsed rock mass during tunnel excavation, characterized by crushing rock. 2. The vertical and horizontal directions of the tunnel face including collapsed rock
At predetermined intervals in the direction of the tunnel length direction.
After filling the hardening material into the tip of each blast hole,
Fire with low blasting power in each of the above blast holes following the volatile material
After sequentially loading the medicine and the explosive with a large blasting power, the curable material is injected into the collapsible rock by the blasting of the explosive with a small blasting power to form a rock stabilization layer,
From the rock stabilization layer, the rock part on the face side was subjected to the above-mentioned blasting force.
A method for stabilizing collapsed rock mass during tunnel excavation, characterized by crushing by explosive explosion. 3. The vertical and horizontal directions of the tunnel face including collapsible rock
At predetermined intervals in the direction of the tunnel length direction.
After filling the hardening material into the tip of each blast hole,
Fire with low blasting power in each of the above blast holes following the volatile material
After sequentially loading the medicine and the explosive with a large blasting power, a curable material is injected into the collapsible rock by the blasting of the explosive with a small blasting power and hardened to form a rock stabilized layer.
A method for stabilizing collapsed rock mass during tunnel excavation , which comprises immediately blasting the explosive powder having a large blasting force on the rear side to crush the rock portion on the face side from the rock stabilization layer .