KR101555618B1

KR101555618B1 - Excavation method for tunnel drilling vibration reduction and increased Chapter (long-hole blasting)

Info

Publication number: KR101555618B1
Application number: KR1020150079246A
Authority: KR
Inventors: 윤은경
Original assignee: 윤은경
Priority date: 2015-06-04
Filing date: 2015-06-04
Publication date: 2015-09-24

Abstract

The present invention relates to an excavation method for reducing vibration and increasing an excavated length during tunnel excavation. More specifically, the present invention is capable of increasing an excavated length and reducing vibration and increasing the excavated length during tunnel excavation for reducing vibration and a noise. The blasting method comprises the steps of: forming an empty hole (100) drilling a large caliber boring hole; continuously blasting toward an upper side and the lower side and the right side and the left side around a center blasting expansion hole (200) and a crack induction hole (300) and an upper blasting hole (400) and a lower blasting hole (500) formed in a lower portion of a center blasting expansion hole (200) and the empty hole (100). Therefore, a neo-smooth blasting method is applied to a periphery of the empty hole (100) to enable blasting, and the present invention secures a free surface toward the front side of the excavation surface.

Description

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an excavation method for tunnel excavation,

The present invention relates to an excavation method for vibration reduction and excavation of a tunnel during excavation of a tunnel, and in particular, there is no basic concept of long-hole blasting in the past, and by applying the reference 20 to 30 years before design, In order to improve this irrationality, we have to increase the size of the armed space to increase the length of the bow by applying the allowable reference value when the support pattern is good or when the blast is applied. And it is made possible to increase the length of the bow, The present invention relates to an excavation method for reducing vibrations and increasing excavation field during tunnel excavation in order to reduce vibrations and noise by using smooth blasting (hereinafter referred to as Neo-Smooth blasting) and maximizing the decoupling effect.

In order to utilize the underground space as a result of the increase in the SOC business in Korea, it is necessary to construct an underground storage facility such as an underground storage facility for various energy and waste, an energy transmission facility such as a communication port, And road tunnels for road traffic such as subways, railways, high-speed railways, national roads and expressways, and so on.

As a method for excavating a tunnel in general, there are various methods such as excavation using TBM, excavation using blasting, excavation using chemical vibration, and the like. Among them, from the viewpoint of economical efficiency of excavation efficiency and excavation cost The most commonly used method is the blasting method.

In general, the tunnel excavation method by blasting includes a perforation step of perforating the deep hole, the deep hole enlargement hole, the bottom hole and the outer hole at a predetermined depth in a first step, and a drilling step of drilling the perforated holes with primers and explosives The loading phase, and the third phase, which are excavated by blasting to expel primers.

However, the excavation method by the blasting is in the form of exploding a large amount of explosives, so that vibration and noise are inevitably generated. However, the blasting technique is required to maximize the blasting efficiency and minimize the noise and vibration simultaneously It has two aspects to do.

That is, in the excavation method by blasting, the blasting efficiency is increased and the vibration noise is largely generated as the used load is larger. On the other hand, as the used load is smaller, noise and vibration are smaller, have.

In particular, the blasting method causes the greatest vibration and noise in the initial blasting, which is very important in tunnel excavation. In other words, the "core minus" is an important factor that determines the success or failure of the overall tunnel blasting by effectively breaking down a part of the center of the tunnel wall first, securing an additional free surface to form two free surfaces. It is very important to secure the initial free surface due to delamination in the tunnel blasting with one free surface, because the result of making the two free sides depends on the success of tunneling.

On the other hand, in connection with the tunnel excavation method, Korean Patent Laid-Open No. 10-2003-37163 (published on May 12, 2003) discloses a method for delamination of a tunnel.

The present invention relates to a method for blasting a part of a section of a tunnel which is to be blasted and plowed as a horizontal centering part, characterized in that the lower centering bolt of the horizontal centering part is adjacent to the lower end face of the tunnel of the tunnel, And a plurality of second deep hole holes and a plurality of second deep hole holes are formed on the outer periphery of the first deep hole and the second deep hole is disposed on the outer periphery of the first deep hole, And the charge of the first centrifugal ball is dispersed in three stages, so that the charge of the first centrifugal ball is released from the charge located at the inlet side of the first centrifugal ball.

According to the present invention, since the lower deep hole of the horizontal core portion is disposed at the same height as the floor hole, and the entire horizontal core portion is moved downward to be positioned at the lower end face of the excavation, It is possible to reduce the noise and vibration generated during the operation. In addition, armed aerials were arranged at the outer perimeter of the first ventricle of the horizontal ventricle so that the surrounding rocks could be more effectively broken by the aerial ventricles when the primary ventricle was blasted.

However, since the first centrifugal blasting operation of the first centrifugal blasting operation is performed under a one-free surface, the use of the charge increases as the concentration of the charge increases for effective blasting, and therefore, Second, there is a problem that the vibration and noise are reduced to some extent by the armed weapon disposed at the outer periphery when the first shunt blasting of the horizontal shunt part is performed. However, The same depth is drilled. Therefore, there is a problem that the vibration and noise transmitted to the outside during the blasting of the first blind hole can not be surely cut off. Third, there is a problem in the vibration of the second blind hole and the third blind hole There is no provision for reducing the cut-off of the horizontal centering portion, Each had such a big problem that the vibration and noise transmitted to the outside.

In order to solve the above-mentioned problems of the prior art and excavate the tunnel by microvibration, the first deep hole of the horizontal core portion is blasted in a state where charge concentration is lowered under two or more free surfaces to minimize the generation of vibration and noise At the same time, it is necessary to reduce the vibration and noise transmitted to the outside when blasting, and to take measures to reduce vibration and noise when blasting the secondary and secondary shafts of the horizontal shim, There has been a need to provide a countermeasure for reducing the vibration and noise generated when the expanded hole is perforated outside.

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Conventionally, an excavation method has been generally used in which a large number of blasting holes (charge holes and armament holes) are formed on the surface of a tunnel and blasting is carried out by loading explosives.

Before the blasting operation, if the boring hole of a large diameter at the central portion of the tunnel is boring (it is a kind of armed means, meaning that the diameter is larger than that of the blasting hole), the blasting efficiency is increased, .

This method is called a tunnel excavation method (blasting method) using a pre-caliber boring ball.

Conventionally, however, since the boring hole of the upper large diameter is formed at a high position in the center of the tunnel and the blasting operation is performed, there is a problem that the blasting efficiency is not good.

(KR) Patent No. 10-1077067 (October 20, 2011) (KR) Patent No. 10-1196700 (October 26, 2012) (KR) Patent Publication No. 2003-37163

In order to solve the above-mentioned problems, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a neodymium- It is intended to apply controlled blasting and decoupling effect so as to reduce vibration by applying smooth blasting (Neo-Smooth blasting).

In other words, if the rocks fractured at the periphery of the center hole are completely moved and discharged forward when the center hole is blasted, the ground rocks can move naturally in the later expansion hole. If the shape of the charge is concentrated at the lower part, In order to solve this problem, it is necessary to charge a small-sized explosive (to the ball inlet) for the purpose of lowering the dosage immediately and increasing the degree of crushing. In order to solve this problem, It is like a modification of smoothing blasting, and it is aimed at increasing the excavation field by using vibration reduction by this blasting method.

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In addition, when the rock wall around the excavated rocks is damaged excessively, it is necessary to reinforce the rock bed due to the fallout and the additional rock due to the overcrowding. As the cracks develop and the groundwater flows, The purpose of this study is to blast the rock to form a free surface in front of the blast while maintaining the natural strength of the rock.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

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1 and 1A, in the tunnel excavation according to the present invention, at a height of 0.3-1.7 m above the bottom surface of the tunnel, a large-diameter boring hole is drilled 50 to 70 m deep toward the front of the tunnel surface, );
A crack guide hole 300 is formed on the outer side of the large-diameter hole 200 and a crack guide hole 300 is formed on the outer side of the large diameter hole 200 in the clockwise direction from the left side of the upper side of the large- The upper blast hole 400 divided into the upper blast hole 500 and the lower blast hole 500 and the lower blast hole 500 and the lower blast hole 500 formed at the lower portion of the larger shank 200, And a blasting step of loading the small-diameter explosives or fine explosives and blasting the rock so that the rock is broken due to the formation of cracks by setting the minimum resistance line to 0.7 m and the pile diameter to 75 mm or 45 mm, respectively In the excavation method,
When the blasting medium is continuously blown in left, right, top, and bottom around the armed aerospace 100, the blasting medium is air and the blasting pressure of blasting is generally 1 × 10 ⁴ cm / m ² 1 × 10 ³ cm / m ² to reduce the blasting vibration and noise, and it is possible to crush the mass of the first quadrangle around the large diameter of the mine,
The blend of neo-Smooth blasting is applied to the periphery of the non-drug ball 100, and the blend of explosives installed in the periphery of the non-drug ball 100 has a diameter of 32 mm, 25 mm explosive with a small diameter is arranged on the upper part,
The deep-focal enlargement hole 200 is formed by forming a square hole of 1, 2, and 3 so as to be blasted, and the hole is enlarged to 375 to 150 times the diameter of the large diameter so that the blast hole 500 and the large- A resistance line of 1500 mm is formed so that the rock is fractured due to the formation of cracks so that a secondary crushing operation is not required and a free surface is secured forward of the excavation surface. It provides an excavation method for the increase.

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The present invention having the above- Apply Smoothing blasting (Neo-Smooth blasting) By using the precision explosive, it is possible to maximize the decoupling effect by maximizing the decoupling effect, and at the same time, to push out the crushed rock in front of the excavation surface, thereby securing the free surface.

In addition, the present invention measures the impact of the ground vibration generated when the ratio of the pore diameter / radius, that is, the decoupling coefficient is different, by artificially weakening the power of the explosive in the charge field, So that the blasting method can be developed.

1 is a conceptual diagram for explaining the boring work principle of the present invention;
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a conceptual diagram showing a front bore according to the present invention. FIG.
2 is an enlarged view for explaining an enlarged view of a crack guide according to the present invention.
FIG. 2A is a perspective view showing a state in which a mixed charge is mounted on an armamentary weapon according to the present invention; FIG.
3 is a diagram illustrating a method for using the decoupling effect according to the present invention.
4 is a graph showing decoupling coefficients according to the present invention.
5 is a view showing the installation state of the measuring instrument according to the present invention and the positional deviation.
6 is a graph showing the maximum vibration velocity and the converted distance by regression analysis for each DL according to the present invention.
7 is a graph showing a vibration value according to the present invention.

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

The excavation method for reducing vibrations and increasing excavation field during tunnel excavation according to the present invention is characterized in that the excavation method for excavating the excavator includes the simultaneous ventilation hole 200, the crack guide hole 300, the upper blast hole 400, 500 and a peripheral hole 600 are formed to charge the explosive device, Smooth blasting is applied and the minimum resistance line of the blasting is 1.5d So that the rock surface is crushed due to the formation of cracks, and the free surface is formed forward, so that the second crushing operation is not necessary.

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The above-described configuration of the present invention will be described in more detail with reference to the drawings.

The rocks forming the tunnel surface are the weakest for the tensile force, the weakest for the shear force, and the strongest for the compressive force.

In the case of forming a large diameter ammunition hole 100 on the surface of the large-diameter surface and blasting, a free surface is formed around the armed fine hole 100. The upper surface of the free surface rock is subjected to tensile force (gravity) So that blasting can be easily performed even with a small blasting force (small charge amount).

Therefore, according to the present invention, an armed aerospace 100 having a diameter of 350 to 950 mm is formed toward the front of the tunnel surface at a height of 0.3 to 1.7 m above the bottom surface of the tunnel (lower than the conventional one) The upper blast hole 400, the lower blast hole 500, and the peripheral hole 600 are formed and blasted.

In this case, the height of 0.3 ~ 1.7m of the weapon mechanic (100) is the lowest position of the weapon mechanic (100) of the large diameter when considering the scale and weight of the real equipment.

Therefore, it is most preferable that the diameter of the armed sponge 100 is 250 to 1000 mm, considering the size, weight, etc. of the equipment.

In addition, the armed weapon 100 is pierced through the equipment at a depth of 50 to 70 meters at once to eliminate the inconvenience of punishing the armed weapon 100 every time a single stroke (one blasting) is performed, and the armed weapon 100 The blasting efficiency is increased when blasting the surrounding charges of the armamentary weapon 100 to increase the excavation field and prevent the occurrence of large vibration, thereby stabilizing the blasting operation of the underground tunnel in the urban area.

In addition, the armed aeronautical instrument 100 can confirm the rock condition of the excavation expected section in advance by using an unmanned surveying device, etc., thereby preventing problems that may occur during excavation work, (100), the ease of use of electricity and power in the tunnel, and the use of electrical primers reduce the risk of electric current due to groundwater.

In addition, the armed aerospace machine (100) is a mechanical method for converting the blasting of one free surface into blasting of two or more free surfaces when the tunnel is blasted, and it is converted into the form of enlarged blasting It is a method of making.

As a result, it is possible to lengthen the excavation field and to use it in the form of a drain hole if the ground water is large.

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In the drawings, the armamentary weapon 100 of the present invention is shown as being punctured only by one gun. However, the weapon weapon 100 may be punched horizontally horizontally with a gap on the surface of the weapon weapon, ) Is reduced by 20 ~ 30% when drilling one hole, 40% by vibration is drilled when drilling two holes, and 50% is decreased when drilling by three holes.

As shown in FIGS. 1 and 2, the explosive is continuously blown out to the surrounding balls at the outside of the armed weapon 100 punctured toward the front of the covering surface as described above, The upper blast hole 400 and the lower blast hole 500 and the lower blast hole 500 are formed on the upper and lower sides of the crack opening 300 and the deep hole enlarging hole 200 to the left and right sides of the deep hole enlarging hole 200, The surrounding hole 600 is formed on both sides and the deep hole enlarging hole 200 can easily excavate the rock by the free surface of the armamentary hole 100 in which the restraining force of the surrounding rock is weakened, Since the restraining force of the surrounding rock mass is weakened by the free surface formed by the preliminary blasting of the deep shrunken hole 200, the guide hole 300 is easily excavated and the upper blast hole 400 The lower blasting hole 500 and the surrounding hole 600 are also connected to each other through the pre- It is a structure that can easily excavate the rock because it is blasted using the free surface.

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The upper blast hole 400 and the lower blast hole 500 and the peripheral hole 600 are sequentially blown in the order of the deep blast hole 200, the crack guide hole 300, the upper blast hole 400, the upper blast hole 400, 2, 3, 4, 5, and 5, respectively, in a clockwise direction along the circumference of the armed spark plug 100 from the left side .

In addition, by forming the deep-shone enlargement hole 200 as a square, diamond, square, and 1, 2, and 3 square balls from the inner side to the outer side of the inner side of the arcuate aperture so as to be sequentially blasted, It is possible to suppress vibration and noise generation at the time of blasting while minimizing blasting while using the free surface in the forward direction, When blasting by applying smooth blasting, a small-diameter explosive or precision explosive is used in the vicinity of the armed weapon 100 to generate a decoupling effect.

At this time, a mixed charge is installed in the vicinity of the armed pores (100). By mixing and arranging other explosives in a mixed charge, a decoupling effect can be generated. That is, the mixed charge is composed of a 32 mm explosive with a large diameter at the bottom and a 25 mm explosive with a small diameter at the top.

In order to maximize the use of the decoupling effect, the blasting vibration is suppressed to the maximum extent and the blasting from the first row to the tool inlet is performed to secure a space in which the rocks after the second row can escape to the front side. As a result, it is possible to blast more than two free surfaces.

The small diameter explosives or Bullet emulsion explosives or emulsion explosives may be used for precision explosives. In addition, since the excavation field increase (long hole blasting) is applied, the air can be removed and the construction cost can be reduced.

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In the present invention, the main reason for using the precision explosive in the vicinity of the armed weapon is to maximize the neodecaping effect to suppress the blasting vibration at the periphery of the armed weapon and to form a free surface. .

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In the present invention, a method of adjusting the violence of explosives may be used to increase the charge density by press-fitting at the time of charge, and conversely, the charge density may be decreased. In the latter case, if the space is maintained between the pore and the diameter as shown in FIG. 3, the explosive force of the explosive causes a buffering action due to the air existing in the space, and is transmitted to the rock in a state where the violence is decreased.

Generally when explosives explode

Is given by Equation (1).

This detonating pressure P _D is transmitted to the medium in contact with the explosive, but in the case of blasting by decoupling, the medium is air. The maximum pressure Pa generated at the interface between the explosive and the air is given by the following equation (2). &Quot; (2) "

If we use the mathematical formula 1 and the formula 2 and give an example of calculation in the actual case, if we use the second kiri dynamite (ρe = 1.4g / cm3, υe = 650000cm / sec) as the explosive, P _D = 1.55X105 (kg / ). When considering air as a medium now, Pa = 12.90 (kgf / cm 2) with ρa = 0.0012 and Ca = 340m / sec. That is, Pa is about 1/1100, which indicates a great decrease in pressure. This is a measure of how effective a layer of air as a cushioning material is in protecting against wall damage.

On the other hand, when the explosive explodes in the charge space, the gas pressure Ps acting in the charge space is given by the Abel-Noble equations.

here,

Ps: Explosive gas pressure acting on the charge ball (kgf / cm2)

f: Oxidizing force (1 · kgf / cm 2 / kg)

L: Explosive load (kg)

V: volume of charge (I)

a: Nose volume of explosives

The covolume a of the explosive

.

In Equation 3 Ps is of course the proportion of the explosive charge, the volume chamber and the lock keulsu So that the force applied to the charge wall is weakened.

That is, by changing the ratio between the intestine compartment volume and the explosive volume, the gas pressure acting on the intestinal wall can be easily controlled.

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As for the characteristics of the topography, geology and rock in the test area 40-127, Shindang 4-dong, Jung-gu, Seoul, the joints on the terraces are developed with vertical joints and irregular low- Flow traces are recognized and thin slices are interlinked, but the overall rock quality on the terraced surface is fresh and massive. The typical trends and inclinations of rocks developed in this area are N65 ~ 70E and 85 ~ 90NW.

On the other hand, after collecting massive rocks from the site, uniaxial compression tests, indirect tensile tests and triaxial compression tests were carried out in the laboratory to investigate the mechanical properties of the rocks. Uniaxial compressive strengths were 1014 ~ 1105kgf / cm2 except for N0.1 and NO.2 boreholes where cracks were already present. Below this level, the rocks were judged to be normal cancer . The apparent density was 2.54 ~ 2.57 gr / cm3 and the porosity was 0.375 ~ 0.627%. The tensile strength obtained from the indirect tensile test was 30 ~ 59kgf / cm2, corresponding to 4.7 ~ 5.7% of uniaxial compressive strength.

The modulus of elasticity was (1.0 ~ 6.547) X105 kgf / cm2 and Poisson's ratio was 0.1555 ~ 0.481. The elastic wave velocities were found to be 1455 ~ 2186cm / sec for S wave and 849 ~ 1270cm / sec for S wave. The tensile strength obtained through the triaxial compression test was 102 kgf / cm2 and the internal friction angle was 59 °. Therefore, it is concluded that the rock mass to be excavated belongs to the common cancer in the classification.

The experimental results on the decoupling effect under these conditions show that as the decoupling coefficient increases, as shown in FIG. 4, the stress acting on the speed and the air wall decreases as the decoupling coefficient increases. Decrease in speed and stress means theoretically a decrease in vibration. Therefore, in the present invention, an appropriate decoupling coefficient is set for the vibration control, and how the magnitude of the vibration varies according to the value is confirmed through local blasting.

Considering the fact that vibration control blasting mainly takes place in the city area, the explosive was selected to be limited and the borehole was limited to 45mm and 75mm considering the performance of the punching equipment which is mainly used in the actual field. In order to compare the blasting using the decoupling effect from time to time, it is necessary to keep the same conditions, so that the present invention is excluded.

In order to obtain a satisfactory decoupling effect, the use of explosive films was carried out in order to prevent compaction.

Table 2 shows the D.L value set for the practice of the present invention, and the workability of the site was considered as described above.

In order to investigate the effect of decoupling coefficient on the magnitude of blasting vibration, the blasting pattern was designed based on the value of D.L as shown in Table 2. This blasting was divided into two stages. First, if the effect of vibration is not taken into consideration, and if it is necessary to set the appropriate amount of space and proper spacing necessary to form cracks in the rock mass, secondly, the appropriate space should be set according to the result of the blasting, The blasting was carried out for the purpose of examining the effect of

The blasting pattern of the first stage was charged at a rate of 25mm and 32mm, respectively, at a cloth factory of 2.7m, a diameter of 45mm, a diameter of 75mm, a hole spacing of 0.5m, a hole capacity of 0.75kg, Three times for each DL, a total of 12 times.

In the second stage, we analyzed the results of the first stage blasting and adjusted the perforation interval. The weight of the ceiling plant and hall was fixed at 2.7m and 0.75kg, respectively, and the perforation interval was changed as shown in Table 3 according to the perforation and diameter.

In this case, three blades were blasted four times at a time by using a primer primer for each D.L. At each blasting, blasting vibrations were measured with four vibration instruments at each blasting.

Bulk emulsion explosives were used as explosives for test blasting.

The blasting vibrator used in the present invention is a measuring instrument capable of measuring vibrations in the frequency range of 5 to 200 Hz at the same time and measuring the width-widening pressure with Instantal's DS-477 and DS-677.

Because the measurement method has some errors due to the characteristics of each vibration system, the values corrected through the comparative experiment under the same conditions were used.

FIG. 5 is a view showing the installation state and measurement position of the measuring instrument when the test is performed.

On the other hand, it is difficult to measure and compare the noise level, ie, air blast, in the field environment where a large number of heavy equipment such as perforation, rock breaking, loading and vehicle operation are operated in a narrow space.

As shown in Table 4, D.L values are divided into four steps of 14, 1.80, 2.34, and 3.00, and the distances between the width and the point are varied from 15.0m to 54m.

The results of Table 5 are regression analyzed for each D.L and are shown in Fig. 6, which is expressed by the maximum vibration velocity and the converted distance. In general, the regression analyzer correlation coefficient (r) tends to be low as the distance between the width and the measurement point is short. However, according to the analysis result of the present invention, the value is between 0.788 and 0.891.

The vibration constants K and n in the vibration estimation equation are summarized in Table 6. Here, the vibration constant is based on the square-root conversion equation.

On the other hand, the magnitude of the relative vibration value will be compared. As shown in Table 5, since the value of n is approximately equal to 1.81, the magnitude of the relative vibration value can be compared with the value of K, which is shown in Table 6, which is shown in FIG.

That is, in FIG. 9, the vibration constant K can be decreased functionally as shown in Equation (5) according to the change of the value of D.L.

Comparing the values in Table 7, it can be seen that the magnitude of the remainder is about 12 to 60% smaller as the value of D.L becomes larger.

As described above, since the present invention was carried out in the urban area, it was controlled so as not to scatter the confinement arms. In other words, general blasting is accompanied by scattering of crushed rocks, which is intended for preceding relaxed blasting.

Therefore, the purpose of blasting is to form only cracks in the rock, which is then removed with a breaker in the next step.

Therefore, it is difficult to quantitatively estimate the crushing arm size as in the case of the conventional blasting. However, it is evaluated based on the crack formation state on the surface and the cracked state observed while removing the rock mass with the breaker.

When the minimum clearance was 0.7 m, cracks were formed in rock masses of 75 mm and 45 mm, respectively.

As a result, the shape of the cracks was almost the same regardless of the decrease in vibration value.

After confirming the blasting condition of the tool part, the breaker arm was finally removed by using a breaker, and then the crushed arm was peeled off during the breaker operation.

However, if we mention the crushing situation, it is judged that there is no difference in the work using the breaker.

In the local rock mass, the geological conditions such as the development state of cracks and the degree of cracks and the difference of rock minerals are significantly different from those in laboratory experiments.

However, it was confirmed that the tendency of decrease in vibration obtained in the present invention was similar to that of the model test for cement mortar.

In this field test, D.L values were set to 1.41, 1.80, 2.34 and 3.00, respectively, and several precedent relaxation blasting was performed in each case. As a result of analyzing the magnitude of relative vibration from the vibration estimation equation obtained by measuring the magnitude of vibration in each case and regression analysis of the result, 0.880, 0.474, and 0.405fhtj Dacelly exponential decline tendency as compared with DL value 1.41 see.

The fracture condition of the rock mass was 0.7m in the minimum resistance line and 75mm and 45mm in the perforation diameter, respectively.

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Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. In addition, it is a matter of course that various modifications and variations are possible without departing from the scope of the technical idea of the present invention by anyone having ordinary skill in the art.

100. Armament spoiler 200. Thick spoiler
300. Cracking inducer 400. Top blaster
500. Lower blasting hole 600. Nearby ball

Claims

Forming an armed phakic hole (100) at a height of 0.3 to 1.7 m above the bottom surface of the tunnel and perforating a large-diameter boring hole at a depth of 50 to 70 m toward the front of the tunnel surface;
A crack guide hole 300 is formed on the outer side of the large-diameter hole 200 and a crack guide hole 300 is formed on the outer side of the large diameter hole 200 in the clockwise direction from the left side of the upper side of the large- The upper blast hole 400 divided into the upper blast hole 500 and the lower blast hole 500 and the lower blast hole 500 and the lower blast hole 500 formed at the lower portion of the larger shank 200, And a blasting step of loading the small-diameter explosives or fine explosives and blasting the rock so that the rock is broken due to the formation of cracks by setting the minimum resistance line to 0.7 m and the pile diameter to 75 mm or 45 mm, respectively In the excavation method,
When the blasting medium is continuously blown in left, right, top, and bottom around the armed aerospace 100, the blasting medium is air and the blasting pressure of blasting is generally 1 × 10 ⁴ cm / m ² 1 × 10 ³ cm / m ² to reduce the blasting vibration and noise, and it is possible to crush the mass of the first quadrangle around the large diameter of the mine,
The blend of neo-Smooth blasting is applied to the periphery of the non-drug ball 100, and the blend of explosives installed in the periphery of the non-drug ball 100 has a diameter of 32 mm, 25 mm explosive with a small diameter is arranged on the upper part,
The deep-focal enlargement hole 200 is formed by forming a square hole of 1, 2, and 3 so as to be blasted, and the hole is enlarged to 375 to 150 times the diameter of the large diameter so that the blast hole 500 and the large- A resistance line of 1500 mm is formed so that the rock is fractured due to the formation of cracks so that a secondary crushing operation is not required and a free surface is secured forward of the excavation surface. Excavation method for increase.

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