JPS62294900A - Method of blasing reinforcing construction - 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] 3. Detailed Description of the Invention [Industrial Application Field] The present invention is used in tunnel excavation work to crush rocks by blasting, and at the same time use the energy released during blasting to crush surrounding rocks. This article relates to a blasting reinforcement method that reinforces loose rock by injecting a reinforcing injection agent into the bedrock.

[Prior Art] When constructing a tunnel by excavating a rocky ground, a hole is drilled in the face, an explosive is loaded into the hole, and the tunnel is excavated using the explosive force of the explosive. However, if explosives are loaded into bedrock and detonated, cracks may occur around the rock, the rock may become loose and the rock may fall, or expensive shoring materials with high resistance may be used to support the loose rock. In some cases, there was a need to strengthen the structure.

When constructing a tunnel in bedrock with many cracks and joints, the loosening caused by blasting can greatly affect the safety of the tunnel, prolonging the construction period, and the need for restoration and repair of collapsed ground. This was causing problems such as increased expenses.

In order to solve these problems, conventionally, a synthetic resin-based or cement-based filler is filled around the explosives loaded in the center of the hole, and then the gunpowder is exploded, and the energy of the explosion is used to fill the filler material. is injected into the cracks in the rock, and at the same time, the energy released during blasting is instantly transmitted to the rock mass through the filler, improving blasting efficiency, and the consolidation effect of the filler injected into the cracks. Measures were taken to prevent rock from loosening and falling.

[Problems to be Solved by the Invention] In the above-mentioned prior art, synthetic resin-based fillers and cement-based fillers (t-ment paste, mortar, etc.) are generally used as fillers. However, in the case of synthetic resin-based fillers, since the main ingredient, curing agent, polymerization initiator, accelerator, retardant, auxiliary agent, stabilizer, and other components are encapsulated and injected, insufficient filling is likely to occur. In addition, two-component heating types do not cure unless the main agent and curing agent are mixed and reacted, and one-component types have problems such as taking too much time to cure.

On the other hand, since cement paste is too filling, the explosion of explosives is likely to be restricted, and there is a risk of dead pressure phenomena occurring. Furthermore, cement molcle has the disadvantage that the material, that is, cement, and water tend to separate, resulting in insufficient penetration into cracks.

[Means for Solving the Problems] The present invention aims to solve the above-mentioned problems. Aerated injection material was created by mixing fine air bubbles in a dispersed state, and on the other hand, holes were dug at regular intervals in the rocky ground with weak bearing capacity, and the holes were filled with the aerated injection material. Afterwards, an explosive is loaded, and then the hole is blocked with a filler and the explosive is detonated.The blast energy is used to crush the rock and excavate a tunnel, and at the same time, the air bubbles are inserted into cracks or joints in the rock around the tunnel. The gist of this method is to inject a pouring material into the tunnel and reinforcing the outer periphery of the tunnel and the facing surface in a zone where the material permeates.

[Example] For a mixture of cement and water, known water retention agents or water reducing agents and dispersants can be mixed, and these cement pastes can be mixed with, for example, SBR latex, ethylene vinyl acetate, polyacrylic ester. It is also possible to mix various synthetic polymeric materials such as epoxy, cellulose derivatives, etc. in the form of powder or solution.

Any type of cement may be used, but one with a small particle size is preferable because it has better penetration into cracks.

An injection material having fine air bubbles is prepared by aeration using a mixture of appropriate amounts of cement and water as described above. In preparing the injection material, a suitable foaming agent and powdered cement may be put into a hopper, water added thereto, and then stirred with a stirring blade to prepare an aerated injection material. In this case, it is possible to use a self-foaming foaming agent such as aluminum powder as the foaming agent, but the present invention is not limited to this, and for example, a protein-based foaming agent may be used. .

In addition, the table below shows a suitable blending example of the aerated injection agent (11I13/per unit).

Types of Foaming Agents Examples of the present invention will now be described based on the drawings. In this example, the cross section of the power plant waterway is 40 m2, the rock quality is alternating layers of shale and chert, and the construction is conducted in a tunnel with elastic waves of 2 to 3 km.

As shown in FIGS. 1 and 2, first, a large number of drilled holes 1 are drilled at regular intervals perpendicular to the facing surface 12 of the tunnel 11. Drilling hole 1 was, for example, drilled using a C4 boom crawler jack with a rond length of 2.7 m and a diameter of 38 my bit, and the drilling length was 2.4 m. The number of holes drilled is 12 holes in 1st stage, 8 holes in 2nd stage, 10 holes in 3rd stage, 8 holes in 4th stage, 10 holes in 5th stage, 10 holes in 6th stage, 7 holes in 7th stage, 6 holes in 8th stage, 5 holes in 9th stage,
There were a total of 99 tubes, 5 in 10 stages and 18 in 11 stages, and the outer peripheral hole was filled with aerated injection material 2 using an injection pipe 3 as shown in FIG. 1q.

Next, an explosive 4 is inserted into the drilled hole 1, and the hole opening is closed with a filler material 5. The amount of explosives per hole is 0.8k per stage (1st and 2nd stage 0.8k).
7k(], 33rd stage 05□, 4th stage 0.3klJ, 5th stage 0.3kl;l, 6th stage 0.7kg, 7th stage 0.3kll
l, 8 stages 0.3kg, 9 stages 0.3k (1, 10 stages 0.
3k (11,11 stages 0..21 CI, charge weight 42,4 kg, gunpowder 1 per m3 of rough cutting is 0.48
It is kllll. Incidentally, the amount of explosives per 11113 excavations in the conventional method was 0.6 to 0.65 kg.

The explosive 4 was detonated by detonating a parent die 6 equipped with an electric detonator using an electric ignition device 7.

The gunpowder used was 29 Enoki dynamite at 25 m/m.

100 (l) was used, and electric detonators were used from DS 1st stage to 11th stage.

The condition of the ground after blasting is as follows.

As shown in Figure 3, the condition of the excavated surface is the chisel mark 1 of drilling hole 1.
4 remained, and a clean arch-shaped excavation surface was formed along the outer hole. Then, the aerated injection material is placed on the tunnel outer periphery 13.
The injection material was injected into the cracks or joints on the right face 12 of the face during blasting, and the injection material permeated zone 15 reinforced the outer periphery of the tunnel and the right face of the face, so the condition was in good condition with no rockfall caused by loosening of the rock. .

The degree of penetration of the aerated injection material into the cracks or joints described above reaches a depth of 20 to 30 CIIl, as determined by the coloration due to phenolphthalin and visual observation, and in some parts, the penetration depth is 30 to 40 cm. This was confirmed.

As described above, according to the present invention, the aerated injection material was blast-injected into cracks or joints in the rock around the tunnel, and it was confirmed that the excavated surface of the tunnel was sufficiently reinforced.

[Effects of the Invention] As described above, according to the method of the present invention, (i) Since the injection material filled into the drilled hole contains a large amount of air bubbles, the drilled hole is completely filled with the injection material. It is also safe because there is a gap in which a chemical reaction can occur due to the ignition of explosives, so no source pressure phenomenon occurs.

(ii> Since the above-mentioned injection material has a suitable matrix and fine air bubbles, the mixture of cement and water is difficult to separate.

(D Since the injection material has fine air bubbles, it has increased fluidity and can be easily applied.

(2) Since the injection material has good fluidity, it easily flows into gaps such as clutter.

Since the amount of the injection material is increased by air bubbles, the amount used during construction is small, and therefore it is inexpensive.

Shield) The injection material easily transmits gas pressure energy,
During blasting, pressure is instantaneously transmitted to the entire circumference of the borehole, and the high-pressure gas has a high resistance due to its penetration into cracks, etc., and has a high rock-destroying effect, so gunpowder is used (only a small amount of sheath is required, reducing the amount of firing caused by blasting).

■Group material injected into cracks or joints by explosion absorbs water on the surface of the cracks or joints, reducing the water content, increasing the strength of the material and making it possible to strengthen the rocky ground. Therefore, the excavated surface of the tunnel can be stably maintained at an early stage.

Funai's injection material has fine air bubbles that can reduce moisture in the injection material, and the injection material injected into cracks can stabilize the rock by absorbing the energy dissipated toward the outer circumference of the tunnel due to blasting. Solution i1' towards the tunnel for
The crank closes and the rock moves for stability. If the injection material contains a lot of moisture and is fluid during this short poem behavior, the rock will start to slide and collapse if the injection material has not sufficiently hardened, but this invention According to the authors, since the aerated injection material contains less moisture, it hardens quickly on cracks and joint surfaces, and the rock mass becomes stable at an early stage.

◇Place the aerated injection material into the holes drilled at regular intervals along the right side of the tunnel face! Since the injection material is fully filled and then injected by blasting, a penetration zone of the injection material is formed along the outer circumference of the tunnel, and the entire excavated surface of the tunnel can be reinforced.

It exhibits various excellent effects such as.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing a part of the process in the present invention, Fig. 2 is an explanatory view showing the R tunnel face portion, and Fig. 3 is a schematic longitudinal cross-sectional view showing the state of injected material permeating the outer circumference of the tunnel after blasting. It is. 1... Hole drilling, 2... Bubbled injection material, 3... Injection pipe, 4... Explosive, 5... Filler, 6... Parent die, 11... Tunnel, 12・・・Face landing surface, 13・
... Tunnel periphery, 14... Chisel marks, 15... Injection material penetration zone. Applicant: Sato Kogyo Co., Ltd. Agent: Ashi 1) Naoe Iris Iris

Claims (1)

[Claims] 1. An aerated injection material is created by mixing appropriate amounts of cement and water into a mixture in which fine air bubbles are dispersed, and at the same time, a hole is drilled into a rocky ground with weak bearing capacity. The holes are dug at regular intervals, and the aerated injection material is filled into the holes, and then explosives are loaded.The holes are then blocked with a filler material and the explosives are detonated, causing the blast energy to destroy the rock. A blasting reinforcement method characterized in that, at the same time as excavating a tunnel by crushing, the aerated injection material is injected into the cracks or joints of the rock around the tunnel, and the outer periphery of the tunnel and the rock face of the tunnel are reinforced with the injection material permeation zone. . 2. The blasting reinforcement method according to claim 1, wherein the aerated injection material is a mixture of appropriate amounts of cement and water and a foaming agent added thereto. 3. The blasting reinforcement method according to claim 1, wherein the aerated injection material is filled into boreholes dug at regular intervals along at least the outer periphery of the tunnel face.