KR100835597B1 - filling method by blasting and groutting - Google Patents

Abstract

The present invention relates to the underground cavity filling method, in particular, when water flows in the underground cavity of the limestone cave or the abandoned mine tunnel area, the blasting block is secured by blasting in the ground and used as a filler. It relates to a joint filling method.

According to the present invention, the cavity filling method by blasting and grouting, in the underground cavity filling method, includes: (a) introducing a casing while forming an excavation hole to a rock which forms a lower portion of the underground cavity; (b) drilling the rock to a predetermined depth; (c) loading and blasting the explosives within the depth of drilling to allow the blast blocks to accumulate inside the underground cavity; (d) a first filling step of filling the aggregate while drawing the casing; (e) injecting an injection tube, characterized in that it comprises a second filling step of filling the cement milk.

Blasting, Grouting, Cavity, Filling, Method, Blasting Block, Water, Lime Cave, Cement Milk.

Description

Joint filling method by blasting and grouting {filling method by blasting and groutting}

1 is a block diagram schematically showing the construction process of the joint filling method by blasting and grouting according to the present invention,

2a to 2e is a view showing the construction process of the joint filling method by blasting and grouting in accordance with the present invention.

The present invention relates to the underground cavity filling method, in particular, when water flows in the underground cavity of the limestone cave or the abandoned mine tunnel area, the blasting block is secured by blasting in the ground and used as a filler. It relates to a joint filling method.

Recently, in order to secure a good linearity of roads, bridges, tunnels and large structures that are inevitably built in limestone are increasing. These limestone zones form limestone cavities due to a series of dissolution and weathering processes. These limestone cavities cause ground subsidence or sinking due to natural collapse during the construction of the structure. Various forms of geological disasters and damages have been reported at home and abroad, including human life and property damage caused by destruction. Thus, the necessity of reviewing the stability of the bearing capacity and settlement of the structure and the reinforcement measures against the hollow and heterogeneous soft layers of limestone area is highlighted.

As a method for reinforcing such a hollow cavity or soft ground, a high pressure spraying method has been widely applied. This technique is called Jet-Grouting in international technical terms. A typical example is R.J.P. Rodin Jet Pile Method, S.I.G. Super Injection Grout Method, S.R.C. Slime Reused Column Jet Grout Method and Clean-Jet Method.

The high-pressure spraying method for the above ground improvement is commonly spraying water, air, grout at a high pressure by using a triple pipe, etc. More specifically, the ground cutting is performed by compressed air on the outside and water spray on the center. The ground is improved by injecting grout material into the cavity to form columnar solid grains. However, each method has a difference in that it is environmentally friendly by applying a displacement method to prevent ground ridge phenomenon, or by recycling a slime, and improving efficiency by adjusting the position of the injection nozzle. That is, the conventional high-pressure injection method (Jet-Grouting) for improving the ground is to spray a cement milk (morment milk) or mortar (mortar) to form a circular solidified body.

The conventional high-pressure jetting method (Jet-Grouting) for the above-mentioned ground improvement is a problem that the injection of grout occurs in the case of large-scale cavities is not economical, it is impossible to cut the hard rock layer (not filled) Co-occurrence), there was a problem that the implementation of the strength of the columnar solid bonds must be limited. In particular, when water flows in a cavity such as a lime cave, there is a problem that the high-pressure jetting method (Jet-Grouting) as described above is practically impossible to apply. That is, there is a problem that a significant amount of grout sprayed by the flow of water is lost. In order to solve such a problem, a quick payment agent may be used, but depending on the flow rate of the water and the size of the cavity, ground improvement may not be possible. In this case, the design route of roads, bridges, tunnels, etc. may be changed. There is no problem.

Accordingly, the present invention is to solve all the problems of the above-described methods, the purpose of the water flow in the underground cavity of the lime cave or abandoned mine tunnel area, or when the hard rock is distributed around the underground cavity In order to provide a common filling method by blasting and grouting, a blasting block is generated by controlling blasting and used as an initial filling material, and then the filling material can be charged again and again through closed blasting and grouting. .

In addition, the other purpose of the cavity filling method by the blasting and grouting can be applied to large-scale cavity, to provide a method of increasing the strength of the grains by adjusting the particle size of the blasting block and the primary filler. In addition, the present invention provides a method for reducing the construction cost by reducing the amount of grout in the ground improvement by the high-pressure spraying method.

As a result, if there is a soft ground (limestone zone or abandoned mine tunnel area) in the track, bridge, tunnel, etc., it is possible to improve the ground without changing the track, especially if there is a limestone zone in which water flows. It is an object of the present invention to provide economic road construction by providing a construction method.

Joint filling method according to the blasting and grouting in accordance with the present invention for achieving the above object, in the underground cavity filling method, (a) introducing a casing while forming an excavation hole to the rock forming the lower portion of the underground cavity; (b) drilling the rock to a predetermined depth; (c) loading and blasting the explosives within the depth of drilling to allow the blast blocks to accumulate inside the underground cavity; (d) a first filling step of filling the aggregate while drawing the casing; (e) injecting an injection tube, characterized in that it comprises a second filling step of filling the cement milk.

When there is a flow of water in the underground cavity, it may be characterized in that the blast block blocks the flow of water.

In the cavity filling method by blasting and grouting, it is preferable to further include the step of injecting high pressure water or air at a high pressure before the first charging step or the second charging step.

In the cavity filling method by blasting and grouting, while the casing is introduced in step (a), the ground investigation for controlling blasting is performed by calculating the size of the blasting block considering the size and shape of the cavity and the radius of influence due to the blasting. The aggregate is preferably at least one or more of gravel, sand, remittal, molten sludge, crushed stone or industrial by-products, and further comprising the step of perforating the confirmation hole after the second filling step to confirm the filling effect.

In the cavity filling method by blasting and grouting, it is preferable that the diameter of the casing in step (a) is 15 cm to 40 cm, and the predetermined depth in step (b) is 2 to 3 times the height of the underground cavity. .

Hereinafter, with reference to the accompanying drawings a joint filling method by blasting and grouting which is a preferred embodiment of the present invention will be described in detail. The present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, only this embodiment to make the disclosure of the present invention complete and to those skilled in the art to fully understand the scope of the invention It is provided to inform you.

1 is a block diagram schematically showing the construction process of the joint filling method by blasting and grouting according to the present invention, Figures 2a to 2e is a view showing the construction process of the joint filling method by blasting and grouting according to the present invention By way of example, it illustrates the cross-sectional layer of the lime cave.

As shown in the block diagram of Fig. 1, the co-filling method by blasting and grouting according to the present invention, schematically, large diameter drilling and casing inlet → blasting in the depth of drilling → primary filling (assembly granule filling) → first Secondary filling (cement milk filling) is made, and may further comprise the step of checking the filling effect.

The above steps will be described in detail one by one.

First, in the ground drilling step, the ground is excavated to a predetermined depth with a perforator, the casing is introduced while forming an excavation hole to the rock which forms the lower part of the underground cavity, and the predetermined depth of the rock (hereinafter referred to as 'depth of drilling') Punch up to.)

Here, reference numeral d of FIG. 2A denotes a depth of drilling, reference numeral D denotes an underground cavity height (for example, a height of a limestone cave through which a flow velocity flows), and the drilling depth d denotes a basement. It is preferable to puncture about 2 to 3 times the cavity height D. This is to ensure that the internal cavity of the underground cavity according to the height of the underground cavity can be blocked by a large amount of blasting blocks so that water flow can be obstructed or blocked.

In addition, it is preferable to carry out the ground survey in order to control the blasting by calculating the size of the blasting block considering the size and shape of the cavity and the radius of influence due to the blasting while introducing the casing.

The next step is the blasting step in the depth of drilling, the step for loading the explosives in the drilling depth of the rock through the casing introduced into the excavation hole, so that the blast block generated by the blasting is accumulated in the underground cavity.

As shown in Figure 2b, the above blasting depth in the perforation depth is a case where there is a flow of water in the underground cavity (for example, there is a cloud of water and the flow rate of limestone cave) or underground cavity of the abandoned mine tunnel area In this case, the inner surface of the underground cavity becomes a free surface, and the blast blocks generated after the blasting are piled up inside the underground cavity, which blocks the water flow in the underground cavity while blocking part or all of the interior of the underground cavity. It is intended to block. This flow or blockage of the water increases the pressure head, which leads to an increase in the groundwater level inside the casing, but the flow rate is reduced by that, thereby preventing the loss of the filler.

In the above blasting depth in the drilling depth, it is preferable to precede the drilling investigation in order to minimize the loss of the aggregate used as the filler in the first step, the first filling step by the flow rate and flow rate of the water in the underground cavity. In the drilling investigation, the estimated data can consider the velocity, the size of the cavity, the shape and the radius of influence due to blasting, and it is preferable to perform control blasting by inverting the size and size of the blasting block generated by the blasting. Prior to this investigation, it can serve as a brace material to maximize the ease of filling when injecting the filling material in the first and second filling step, the next step, not only precise construction is possible by such control blasting, in particular According to the joint drilling, it is possible to obtain the effect that proper precision construction becomes more certain, and it can be used as a review data to determine construction suitability later.

Next, the primary filling step is to draw the casing to the upper part of the underground cavity to a certain height, and then fill the aggregate between the blast blocks stacked in the underground cavity. To this end, an injection device installed on the ground is used, and an injection pipe connected to the injection device is introduced into the casing, and the aggregate is filled through the injection pipe.

As shown in Figure 2c, as the aggregate used as the filler in the first filling step, it is necessary to select the filler in consideration of the effective charging during the second charging to be carried out, the aggregate aggregate It is preferable to use, and the coarse aggregate may be used as the primary filler including at least one or more of gravel, sand, remittal, molten sludge, crushed stone or industrial by-products. When the primary filling with such coarse aggregate increases the pressure head more than the blasting step, the flow rate is reduced by that to prevent the loss of cement milk during the secondary filling.

Here, prior to filling the aggregate through the injection tube, prior to spraying at high pressure while controlling the pressure of air and water through the injection tube using a compression pump and an air compressor (Air Compressor) attached to the injection mechanism Of course you can.

In this way, by performing the secondary filling step described later in the state where the primary filling is performed inside the underground cavity by the aggregate, that is, as the filling step by step, the watertightness is increased and the occurrence of erosion can be minimized. It is possible to appropriately use the pressure under the control of the air compressor in consideration of the confining pressure, which can be referred to as the flow rate, the pressure which hinders the flow of water, the injection pressure of the aggregate injected through the injection pipe, and the like. In addition, it is possible to verify the filling effect through the observation of water level fluctuations and pressure in accordance with the filling of the aggregate.

And it is possible to check the construction effect step by step, it is easy to change the appropriate fillers (aggregates) by checking the construction effect, and the equipment used to recycle the slime (Ito) in the conventional filling method is unnecessary, so additional The accompanying process is unnecessary, and regardless of the type of aggregate used for the primary filling, it can be freely changed depending on the working conditions in a manner other than the injection method through the injection tube.

Next, as a second filling step, a filling tube is introduced into the casing to fill cement milk in the gap between the blasting block and the aggregate filled in the first filling step. As shown in Figure 2d, the cement milk used as the filler in the secondary filling step is injected by using an injection mechanism, in detail by injecting at the pressure of the pump to fill the pores or cracks in the underground cavity and ground The fragile layers unite and harden, preventing the collapse of the ground.

On the other hand, in order to achieve the purpose of the compact charging, after the first charging, a plurality of filling holes for the second charging can be perforated around the filling hole at the time of the first charging, newly drilled charging Injecting the tube into the ball, it is preferable to fill the cement milk through the injection tube.

In the second charging step, the amount of cement milk should be increased according to the reinforcement (charging) area, the area for solidification during the second charging is to be set, and the water resources are maximized to maximize the pocket effect of the filling of the closed room. The injection standard of the construction is applied, and through the spatial distribution of the newly drilled filling hole, it is possible to check the state of the primary filled area, that is, the filling effect, and to prevent additional scour caused by running water. As a result, long-term stability can be obtained. In addition, it is necessary to consider inducing the filling of the chamber for expressing a firm strength, there is a need to secure the base strength and seismic strength.

Finally, after the secondary charging step, it is preferable to carry out further comprising the step of confirming the filling effect of verifying the structural safety of the upper structure by drilling a hole for checking the state of charge.

As shown in FIG. 2E, the inspection hole is drilled around the perforation hole, and the sample is collected to verify the filling effect by performing coloring, permeation, and water pressure tests of the strata, and confirming the filling reinforcement area. It can also be used as a basis for large diameter filling pipes that were drilled into the inspector while drilling. Here, the field test can be performed, and in detail, the construction state can be confirmed through core state, block substrate ratio, permeability, water pressure, teleview, coloring reaction, exploration, well logging, and the like. The structural safety of the superstructure can be verified by the ratio of strength, durability and filler material.

On the other hand, it is also possible to check the construction state by performing a test using a steel pipe to the filling hole subjected to the first and second charges. By conducting this test to confirm the filling effect, it is possible to secure the linkage with the process of installing the direct foundations continuously, and obtain the strategic design and information under similar ground conditions.

The joint filling method according to the blasting and grouting according to the present invention, which is composed of these steps, is applicable even when the rock around the underground cavity is hard rock, and the gravel, crushed stone, It is preferable to use sand, expansion order material, cement and the like, and the strength of the improved body is preferably 200 to 300 kgf / cm 2, but the strength may be adjusted depending on the condition of the ground.

As described above, the joint filling method by blasting and grouting according to the present invention corresponds to a preferred embodiment, and the present invention is not limited to the above-mentioned specific preferred embodiment, and the gist of the present invention as claimed in the claims. Various modifications can be made by those skilled in the art without departing from the scope of the invention, and such modifications are within the scope of the claims.

According to the present invention having the above configuration, there are many effects as follows.

First, it is possible to improve the ground in limestone caves or abandoned mine tunnels where water flows, so it is possible to construct without changing tracks such as roads, bridges, and tunnels, and it is possible to economically improve ground even if there are large cavities.

Second, it is possible to dictate the design through control blasting and primary and secondary charging, and to induce precision construction by verifying the charging effect in each stage of the primary and secondary charging.

Third, not only can filling underground cavity tightly by the 1st and 2nd filling, but also because the filling amount of cement milk is not generated excessively by filling cement milk in the state filled with primary aggregate, the construction cost is reduced. It is possible to change the filler (particle size, solid phase, liquid phase) and freely.

Fourth, since the strength is increased by the particle size control of the primary and secondary fillers, it is possible to convert to a direct basis.

Fifth, it can be applied even when the rock around the underground cavity is hard rock.

Sixth, the workability can be clearly confirmed, and the stability of scour in the long run can be secured.

Claims (5)

In the underground cavity filling method, (a) introducing a casing while forming an excavation hole to a rock forming a lower portion of the underground cavity; (b) drilling the rock to a predetermined depth; (c) loading and blasting the explosives within the depth of drilling to allow the blast blocks to accumulate inside the underground cavity; (d) a first filling step of filling the aggregate while drawing the casing; (e) a second filling step of filling cement milk by injecting an injection tube; Joint filling method by blasting and grouting comprising a. The method of claim 1, There is a flow of water in the underground cavity, the joint filling method by the blasting and grouting, characterized in that the state of the water by the blasting block to hinder the flow of water. The method of claim 1, And a step of injecting air and water at a high pressure using an injection tube before the first charging step or the second charging step. The method of claim 1, Conducting ground survey to control and control the blasting block by calculating the size of the blasting block considering the size and shape of the cavity and the radius of influence due to the blasting while introducing the casing in step (a); The aggregate is at least one of gravel, sand, remittal, molten sludge, crushed stone or industrial by-products; Punching the confirmation hole after the second filling step to determine the filling effect of the joint filling method characterized in that it further comprises a blasting and grouting. The method according to any one of claims 1 to 4, The diameter of the casing in the step (a) is 15cm ~ 40cm, The predetermined depth in step (b) is a joint filling method by blasting and grouting, characterized in that 2 to 3 times the height of the underground cavity.

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