KR100534148B1 - a Fracture controlled blasting method using split tube and air decking - Google Patents

Abstract

The present invention relates to a crack control blasting method using a split tube and an air layer.

In particular, it is punctured at regular intervals along the boundary line of the member or rock on which the cutting surface is formed, and two lines of slits facing 180 degrees in the longitudinal direction are dispersed and fixed by using a cylindrical paper tube facing the boundary line. And exploding the upper and lower explosives at the same time using detonators with the same parallax, but detonating all adjacent balls at the same time or detonating them with the shortest possible parallax using the parallax of multistage blasting machines and non-electrical primers. It is done.

Accordingly, when the dismantling of a building, large concrete foundations are cut, the surface is formed on rock slopes when the excavation is open, and the blasting for excavation of the rock during tunnel construction minimizes damage to surrounding members or rocks and allows the cutting surface to be formed in the desired direction. will be.

Description

Fracture controlled blasting method using split tube and air decking

The present invention relates to a crack control blasting method using a split tube and an air layer at the same time, and more specifically, to cut a large concrete foundation by using the impact control effect of the air layer and a crack control effect using a paper split tube. Finally, the present invention relates to a crack control blasting method using a split tube, a split tube, and an air layer that can minimize damage to surrounding members or rocks and effectively form a cut surface in a desired direction during rock formation for tunnel construction.

In general, gunpowder blasting is the most common method for destroying materials by using gunpowder. First, blasting is carried out by loading explosives into the perforated balls, and when the explosives explode, high-temperature heat and high-pressure explosions occur. Will destroy the material.

At this time, what is necessary for efficient destruction is to fill the explosives so that there is no gap in the blasting holes so that energy can be efficiently transmitted, and arrange the blasting holes so that an appropriate force can be applied according to the characteristics of the material.

However, when blasting is carried out for the purpose of removing only a part of the material, it is necessary to blast it so that the material of the part not removed is not damaged.

For example, when forming rock slopes or digging tunnels, they should not be damaged around the slopes or tunnels. If damaged, they may cause slope collapse or tunnel collapse.

In addition, even in the case of taking blocks from rock for building stone, it is necessary to form cracks on the cut-out interface as if cut off with a knife and not to damage the rest.

In the case of such a structure disassembly, it is necessary to form only a crack for collapse and to prevent over-breaking and scattering.

In order to satisfy this need, a general blasting method is difficult and a specially designed control blasting method should be applied.

Such control blasting methods include a decoupling charge method, a linear crack blasting method, a smooth blasting method, a line drilling method, and a crack control blasting method using an air layer.

The decoupling charge method is a method of using a decoupling charge, which is to reduce the density of the explosives to relieve the energy of the high temperature and high pressure generated when the explosives explode, and to charge the explosives having a smaller diameter than the diameter of the blast hole It forms a space between the explosives and the blasting wall to allow a buffering action.

This decoupling charge is to install a wing-shaped device around the rod-shaped explosive as shown in Fig. 1 so as to give a certain distance between the explosive and the perforated wall.

In addition, the pre-split blasting method (pre-splitting) is a method of blasting the blast holes perforated on the excavation schedule line before the blasting to form a cutting surface and then staggering the remaining portion or blasting in a secondary operation.

At this time, the loading method of the explosives of the excavation schedule line uses the explosives for the control blasting and protects the rock on the work finish surface by using the decoupling effect.

This method is mainly used to form the last slope of the rock slopes of the open air, and the balls of the fractured planes are drilled with small spacing in order to form a good cross section.

However, it is difficult to apply in a tunnel with a high strength of acupressure, and there is a problem in that the blasting vibrations may be somewhat large by blasting at the same time, although the charge density of the blasting holes is small.

In addition, the smooth blasting method, like the general blasting, blasts the blasting hole of the expected excavation surface lastly, narrows the ball spacing of the excavation schedule line, and has a smaller diameter and lower charge density than other balls, such as explosives for controlled blasting. Using explosives with a decoupling effect protects the rock on the finishing surface.

This method is mainly used to protect the surrounding rock and obtain a smooth white surface when constructing a tunnel.

However, the ratio of the space between the smooth blasting hole and the minimum resistance line between the adjacent holes is important, and the charge of the adjacent holes is important, which increases the overall process for blasting. It is difficult to form a smooth surface by disturbing even the rock body behind the planned excavation surface before the construction.

Subsequently, the above-mentioned line drilling is a method of forming a fracture surface by drilling a plurality of near-seamless holes to the fracture scheduled surface so that the dynamic stress generated during the blasting causes cracking between the undamaged holes.

However, the difference from the smooth blasting method or the precracking blasting method as described above is that the puncturing interval is much narrower and does not charge the ball, which requires a lot of puncturing cost and is economically disadvantageous.

In addition, the crack control blasting method using the air layer is the same as the conventional blast blasting method to blast the blast holes of the excavation schedule line than the blast hole, but the charging method is different.

This refers to a form of placing a layer of air on the top of the explosives charged at the bottom of the line crack blast hole, which can be referred to as a kind of intensive charge method, and loads the explosives at the bottom of the line crack blast hole or its adjacent hole, An appropriate point on the top of the blast hole is blocked with an air bag or plug to create a layer of air between the explosive and the cap.

In addition, the part corresponding to the upper part of the airbag or the plug does not color, and in some cases, it may be filled with a color material. When explosives explode, gas pressure is transferred to the air layer, and the quasi-static gas pressure causes tensile stress between the ball and the ball. And the cutting surface is formed by this tensile stress, and the explosives are loaded only in one part of the blast hole, thereby minimizing the environmental damage caused by the explosives.

However, in the above method, the explosive cost is low, but the airbag or plug used for forming the air layer needs a special material and shape by high pressure, and various kinds have been developed and marketed, but require a separate expense.

On the other hand, wing hole blasting, which creates a groove in the perforated wall, causes stress to be concentrated and initiates cracking. In order to make a groove, a special type of excavation equipment has to be put in and it takes a long time to work, which is economically disadvantageous.

In addition, there is also a method using a depot wire using water as a colorant, but there is a difficulty in that water does not come out of the ball at the point to supply water and in the horizontal hole.

An object of the present invention for solving the above problems, such as dispersing charges and paper using an air layer to solve the difficulties of construction according to site conditions, generation of blasting pollution such as noise, increase in the cost of using a special device, etc. The present invention provides a crack-controlled blasting method using a split tube and an air layer that enables the blasting using an inexpensive split tube together to form a fracture surface more economically and efficiently.

In order to achieve the above object, there is provided a split tube in which the plug is fixed to both ends of a body which is usually formed, and slots are formed in the longitudinal direction of the body in the 180 degree direction, respectively.

In another aspect, the present invention, the step of puncturing a plurality of blast holes along the rupture plan line of the area to be blasted;

Attaching primers to explosives to be inserted into the blast holes of the individual;

Charging the explosive to form a hermetic air layer having a directional opening substantially parallel to the predetermined line between two or more explosives inserted into each blast hole formed along the predetermined line;

Compacting an upper portion of the blast hole where the explosive is charged;

Provided is a crack control blasting method using a split tube and an air layer, including blasting after connecting each primer.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 to 4, the split tube 200 has a plug 120 fixed to both ends of the body 100 made of a hollow cylindrical paper, and 180 inside the longitudinal direction of the body 100. A plurality of slits 110 are each formed to maintain the degree.

In addition, the explosives 130 are spaced apart from the inside of the split tube 200, and the explosives 130 are respectively inserted and fixed to the body 100 by the fixing band 140, and the primers 150 are respectively inserted into the explosives 130. .

The operation of the split as described above is as follows.

As shown in Figures 2 and 3, the explosives 130 having a relatively low velocity and a large gas pressure effect are dispersed and charged into the upper and lower portions by using the split tube 200 inside the blast hole 170, and then the color is applied to the upper portion. Ash 180 is inserted, and the space between the two explosives forms an air layer so that the expansion pressure of the gas generated when the explosives installed on the top and the bottom explode is transmitted to the outer rock or member to the air layer.

As described above, the explosive agent 130 is fixed to the paper split tube 200 in which the slit 110 is formed by the fixing band 140 or the like, so that the slit 110 is formed in the split tube 200 during the explosion. By concentration, cracks are preferentially generated and directed in the direction of the slit.

In addition, the slit is formed in the cylindrical paper split tube 200 formed with two rows of slits 110 formed to face each other (180 degrees apart) after drilling the blast holes 170 formed at a predetermined interval along the fracture plane predetermined line. The 110 is installed to face the adjacent ball on the fracture plan line, wherein the line extending the slit 110 coincides with the fracture line plan line.

Subsequently, the explosive charge 130 is loaded at appropriate points of the upper and lower portions of the tube 200, and the discharging charge having a space is provided between the explosive charges 130 inserted into the respective blast holes, and the explosive charges of the upper and lower parts are carried out. Deny 130 at the same time using a quick primer or a delay primer having the same parallax.

In addition, other balls on the fracture plan line including adjacent blast holes may be detonated at the same time using the net primer 150 or a delayed primer having the same parallax, or by detonating a very short step using a multistage blast or non-electric primer. Minimized damage around the fracture line due to the buffering effect using the air layer and smooth fracture surface by inducing the direction of crack formation toward the adjacent holes located on the fracture plane by stress concentration around the groove of the paper split tube. To form.

On the other hand, the blasting method of the present invention, first punctures a plurality of blasting holes along the intended plane of the fracture surface of the area to be blasted.

Subsequently, primers are attached to explosives to be inserted into the blast holes of the individual.

Then, the explosive is charged to form a hermetic air layer having a directional opening substantially parallel to the predetermined line between the two or more explosives inserted into each blast hole formed along the predetermined line.

In this case, the explosive is always inserted into the paper split, the slits are formed in the longitudinal direction of the hollow body in the 180-degree direction, respectively, and fixed after using the band or the like always brings a constant effect.

In addition, the explosives inserted into the blast holes are mounted on the split so that explosives into which the primer of the same pattern is always inserted from the bottom to the top can be used.

Subsequently, the upper part of the blast hole in which the explosive is charged is compacted using a coloring material.

Then, after connecting each primer, press the blasting switch to blast along the intended fracture surface of the blasting area.

On the other hand, the upper and lower charges of the blast hole uses a low explosives and a large gas pressure effect, and the amount of explosives is determined through the test blasting according to the site conditions, but the draft explosives, emulsion explosives, ANFO and equivalent explosives are used.

In addition, the installation direction of the primer is to be installed so that the detonation direction is in the cooperative direction in the case of the upper charge, the demolition direction is mounted in the tool direction in the case of the lower charge.

In addition, the detonation is carried out using an electric primer or a non-electric primer, and the charges dispersed in the upper and lower portions in each blast hole takes a method of simultaneously blasting into a burst primer or a delayed primer having the same parallax, and the entire blast holes are fired. Detonation at the same time using primers or delayed primers with the same parallax or appropriately adjust the steps in adjacent spaces according to site conditions, but basically 10 milliseconds (10/1000 seconds) using multistage blasters or non-electric primers Detonate so as not to exceed.

In addition, the upper portion of the upper charge is colored using clay, sand or rock powder.

The blasting method of the present invention having the configuration as described above will be described in detail.

According to the present invention, the explosives having a relatively low velocity and a large gas pressure effect are distributed and charged from the inside of the blast hole to the top and the bottom, and the space between the two medicines is provided with a grooved paper split tube to detonate the upper and lower medicines at the same time. At the time, the desired fracture surface is formed by inducing cracks to preferentially generate and proceed in the direction of the grooves by using the buffering action of the air layer and the concentration of pressure generated in the grooves formed in the paper tube.

In particular, it is economically advantageous by using paper tube, and it is time and manpower required to prepare paper tube as much as the number of blasting holes before installation, install explosives on the upper and lower part, and insert it into the blast hole during the loading work. Can be reduced.

The explosives mounting, using a split tube to prepare a cylindrical cylindrical flow and to form two rows of slits to face 180 degrees in the cylindrical direction, and fixed the explosives in the upper portion of the split tube using a tape or the like.

In addition, the explosives may be necessarily located only inside the cylinder, and a predetermined portion may be exposed to the outside of the tub portion.

Subsequently, the explosives are fixed with a tape or the like in the same manner as in the upper portion of the split tube.

When the explosive is mounted on the split tube, the explosive is prevented from being displaced in one direction due to the difference between the diameter of the explosive and the diameter of the split tube, and the role of preventing the deformation of the tube in the blast hole and the colorant are pushed into the tube. It is better to use a plug to avoid going.

Subsequently, the explosives of the upper and lower portions inserted into the blast hole are respectively provided with a quick primer or a late jet primer of the same parallax, each of the lead wires are tied, and the length of the lead wire has a sufficient length to connect with the bus bar outside the ball. Should be.

Then, the above steps are repeatedly performed through the split tube prepared by the number of blast holes for installing explosives, and inserting the split tube with explosives into each blast hole.

In addition, the detonation method of the blast hole can be applied to tunnel blasting and open blasting, as shown in Figs. 5a and b, and in the case of tunnel blasting, the final surface is formed in the perforated hole (design dig). Apply to the excavated surface.

To explain this, first, puncture the blast hole 170 and insert the explosive-loaded tube 200 into each ball and connect the lead wires of the primer, and each blast hole is simultaneously detonated or the parallax of the adjacent space is within 10 milliseconds. Detonation, the time difference can use a multi-stage blast or non-electric primer.

Experimental Example 1

In order to evaluate the field application effect of the present technique, the test blasting on the field rock was carried out to investigate the control effect of the location and growth direction of the crack.

The field test was conducted at the aggregate production blasting site of K Industry located in Namwon, Jeollabuk-do.

The rock that constitutes the quarry is widely distributed in granite called Namwon granite of the Mesozoic Jurassic.

The test blasting procedure involves (i) selecting the target rock and mass, (ii) designing the drilling and loading patterns, (iii) drilling, (iv) assembling the split tube, (v) charging and coloring, and (vi) blasting. , (vii) fracture observation and fracture investigation.

In addition, this test was divided into two types, (i) test for general blast hole and (ii) test using split tube, so that the crack control effect for fracture surface formation could be compared with each other.

end. Selection of rock and mass to be tested

The rock masses used in the field test were selected for rock masses of more than 2 m in all three axis directions. In the case of rock mass, the drilling position was set on the bench wall with a bench height of 10 m or more. The main physical properties of Namwon granite, the target rock of this test, are shown in Table 1.

I. Drilling method

Crusher drill was used to drill the selected rock, and two explosive holes, 75 mm and 42 mm in diameter, were drilled to change the size of the blasting pressure acting on the blast hole wall using the same explosives. It was.

All. Split tube assembly and charging method

The type of explosive used in the test was based on the size of the mass or the condition of the rock, and the emulsion explosives and the precision explosives were mixed and detonated using an electric primer. Table 2 shows the main specifications of explosives used in the test.

And, in order to examine the effect of the color development was tested in the case of using the chromophores and when blasting in a non-colored.

In addition, the material used for the split tube was paper and PVC, the length of the tube was 1 m, and the bit was worn according to the drilling process. Therefore, the outer diameter of the new bit is 75 mm and 42 mm. Since the actual hole diameter is about 63 mm and 40 mm, 60 mm and 39 mm diameter tubes were used to smoothly insert the tube into the blast hole.

When the tube was manufactured in the form of a split tube loaded in an actual blasting hole, a circular tube was cut in two directions in the longitudinal direction, and the explosives were fixed with a tape or the like inside the cut tube.

After the explosives were fixed in one of the tubes cut as described above, the remaining tubes were combined with each other so that they could be inserted into the blast hole, and as mentioned above, to examine the effect of the material of the tube on the crack surface formation, Tubes and paper tubes were used for testing. Tube materials such as PVC and steel are used in many existing studies, but in extremely rapid detonation reactions, soft materials such as paper are expected to cause considerable resistance, thus splitting low-cost tributaries. The practicality was tested by using it as a tube.

From the test results for the general blast hole, the appropriate dose was calculated in consideration of the size of the rock, the diameter and the depth of the blast hole, and when the explosive pressure was charged in order to prevent the explosion pressure from working intensively in a specific place within the split tube, Dispersed in and loaded.

In addition, when a precision explosive was used as a column charge, an emulsion explosive was used as an explosive and an on-site stone powder was used as a clay.

la. Detonation method and crack surface investigation method

In this test, three test blastings were carried out on the general blasting hole first, and nine crack control test blastings were carried out on the blasting hole loaded with the split tube. The detonation method used simultaneous blasting using a net primer in all blastings.

hemp. Results and Discussion

The main test conditions and results applied in this test blasting are shown in Table 3.

In this regard, first, in the general circular hole blasting test, the appropriate dose to be formed without breaking is obtained, and the dose required for crack control blasting using the split tube is determined based on the obtained appropriate dose.

In general, the types of colorants and color lengths are known to have a great influence on the blasting results.

Therefore, in the case of non-color blasting, a very large dose was required to form a fracture surface around the blast hole.

The split tube is known to act to cause fracture cracks to develop from the slit by concentrating the stress wave generated by the explosive detonation in the slit part of the tube. It was confirmed that it was spread.

In addition, the test using rock mass showed the characteristics that the crack started at the position of the slit, progressed to some extent in the propagation direction to be controlled, and then the fracture surface was formed toward the free surface.

That is, the propagation direction of the crack was controlled in the planned direction at the position of the slit, but the propagation length of the crack was difficult to accurately measure because the propagation direction was changed by the influence of the free surface.

On the other hand, in rock-controlled blasting targeting rocks, the propagation length as well as the direction of cracking could be measured with relative accuracy.

On the other hand, detonation pressure generated during blasting is known to play the most important role in destroying the medium.

Therefore, in this test, the detonation pressure was calculated using the equation that can express the pressure acting on the blast hole wall according to the type of explosive and the size of pore size, and compared it with the degree of crack control.

To calculate the detonation pressure, two equations suggested by the National Highway Institute in the United States in 1991 were used.

In the above formulas, PD = explosion pressure (kbar); SGe = specific gravity of explosive; Ve = speed (ft / sec)

PB = decoupling blast pressure (kbar); dc = weak diameter; dh = Respect

Detonation pressure and crack length formed as a result of the field test calculated by the blasting using the split tube by the above equation are shown in FIG.

Fig. 6 (a) shows the relationship between the calculated value and the crack length by calculating the detonation pressure acting in the blast hole, and Fig. 6 (b) shows the crack length ratio expressed by the ratio of the controlled crack length to the pore diameter. And the relationship between the crack length ratios.

In addition, the material of the split tube was used for the paper tube in the case of rock, PVC tube in the case of rock.

And when the detonation pressure required to start a crack in a rock was about 1.5 GPa, and when the magnitude of the detonation pressure was 2.5 GPa, a crack generate | occur | produced also in the wall part of tubes other than a slit.

When the size of the detonation pressure was less than 1 GPa, crack control was impossible due to the co-occurrence.

In the case of rock, cracking started at the slit position of the tube even at a pressure of 700 MPa smaller than this, but cracking did not occur at the portion other than the slit, and the propagation length of the control crack by the split tube was 120 cm, about 30 times the pore diameter. Appeared to

In addition, it was shown that rock blasting using split tube was able to control cracking up to 30 times of pore size, which is a space spacing applied in conventional controlled blasting techniques such as smooth blasting or linear cracking blasting. It is much higher than 5-10 times.

As described above, according to the present invention, as a result of the field blast test, it is possible to control the crack to proceed in the slit direction by using the split tube, and to control the direction of generation of the fracture surface using the split tube, the material of the tube The effect of using inexpensive materials such as this paper was obtained.

In addition, it is economically advantageous by using paper tube, and it is time and manpower required by preparing paper tube as much as the number of blast holes before installation, installing explosives on the upper and lower parts, and inserting into the blast hole during the loading work. The effect is to reduce.

While the invention has been shown and described with respect to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit or scope of the invention as provided by the following claims. I would like to clarify that those who have knowledge of this can easily know.

1 is a perspective view showing a conventional decoupling charge.

Figure 2 is a perspective view showing a split tube according to the present invention.

Figure 3 is a perspective view showing the explosives mounting state of the split tube according to the present invention.

Figure 4a, b is a perspective view showing an installation state of explosives using a split tube, respectively, according to the present invention.

5 is a flowchart illustrating a crack control blasting method according to the present invention.

Figure 6a is a graph showing the characteristics of the crack control length according to the explosion pressure of the present invention.

Figure 6b is a graph showing the characteristics of the crack development ratio according to the explosion pressure of the present invention.

* Description of the symbols for the main parts of the drawings *

100 Body 110 Slit

130 ... width 140 ... fixed band

170 ... blast hole 180 ... coloring material

Claims (7)

delete delete Drilling a plurality of blasting holes along a fracture line planned line of the blasting area; Mounting primers on explosives inserted into the blast holes of the individual; Loading the upper portion of the blasting hole where the explosive is charged as a colorant; In the blasting method comprising the steps of blasting after connecting each primer, A split tube between the two or more explosives inserted into each blast hole formed along a predetermined line to form a hermetic air layer having a constant opening in parallel with the predetermined line, thereby distributing and charging the plurality of explosives in sequence; Crack control blasting method using air layer. According to claim 3, wherein the upper and lower charges of the blast hole uses a low explosives and a large gas pressure effect, the amount of explosives is determined through the test blasting according to the site conditions, but the draft explosives, emulsion explosives, ANFO and equivalent explosives Crack control blasting method using a split tube and the air layer, characterized in that to use. The split tube and the air layer of claim 3, wherein the installation direction of the primer is directed so that the detonation direction is in the cooperative direction in the case of the upper charge, and the detonation direction is in the tool direction in the case of the lower charge. Crack control blasting method using According to claim 3 or 5, wherein the detonation of the charge using an electric primer or a non-electric primer, the explosive detonator charged in the upper and lower parts in each blast hole is a simultaneous primer or a delayed primer having the same parallax simultaneously A crack control blasting method using a split tube and an air layer, characterized in that using a multi-stage blasting machine or a non-electromagnetic primer to prevent it from exceeding 10 milliseconds. According to claim 3, wherein the charge of the explosive is fixed by a cylindrical paper flow portion of which a portion of the explosive is in contact with each of the two ends is fixed as a band, the paper container is two facing 180 degrees in the longitudinal direction of the cylinder A crack control blasting method using a split tube and an air layer, characterized in that to form an opening by forming a slit.