Novel non-coupling smooth blasting method
By designing peripheral holes, slot holes and auxiliary holes in gloss blasting, and adopting axial and radial uncoupled charging structures, the problems of difficulty in taking into account both blasting vibration hazards and blasting effects in the prior art are solved, and an efficient, safe and economical gloss blasting effect is achieved.
Patent Information
- Application Number
- CN202510124646.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-26
- Publication Date
- 2025-03-07
AI Technical Summary
While reducing the damage to blasting vibration, the existing gloss blasting technology is difficult to ensure the blasting effect. The explosive charge is large and the construction efficiency is low, which affects construction safety and economy.
The design of peripheral holes, slot holes and auxiliary holes is adopted, combined with the axial and radial uncoupled charging structure, the medicine roll is connected through a detonation cable to reduce the blasting pressure peak, extend the blasting action time, and control blasting vibration and rock mass failure.
It has achieved the effect of low explosive single consumption, low blasting vibration hazard, high construction efficiency and good gloss blasting effect, reducing surrounding rock damage and later reinforcement costs, and improving construction safety and economy.
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Figure CN119573491A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the technical field of blasting engineering, and specifically relates to a novel uncoupled smooth surface blasting method with low explosive consumption, small blasting vibration hazard, high construction efficiency and good smooth surface blasting effect. Background Art
[0002] Smooth blasting technology is a blasting technology that achieves precise control of blasting energy by optimizing parameters such as explosive charge, blasthole arrangement and detonation sequence, thereby reducing damage to the surrounding rock and forming a smooth and flat contour on the rock surface after blasting. Compared with traditional drilling and blasting construction, smooth blasting technology has many advantages such as less disturbance to the surrounding rock, regular shaping after blasting, facilitating the safety of subsequent construction processes, effectively controlling over-excavation and under-excavation, and saving initial support construction costs. Therefore, it plays a pivotal role in the fields of mining, tunnels, underground engineering, etc.
[0003] Traditional smooth blasting technology mostly uses a coupled charging structure for blasting. Due to the influence of the rock physical and mechanical properties such as the rock stratification and lithology on site, explosive cracks are easily generated on the hole wall and are very easy to develop along the original cracks and joints of the rock mass. Therefore, the expansion of explosive cracks is very random and uncertain, and the fracture direction is difficult to control, which can easily lead to large over-excavation and under-excavation of the rock mass, low blasting efficiency, low half-eye mark rate, poor forming quality, and serious loosening of the surrounding rock.
[0004] In the existing technology, in order to solve the problems existing in the traditional smooth blasting technology, the smooth blasting technology can be divided into three types: contour drilling method, pre-splitting blasting method, and smooth blasting method. (1) The contour drilling method is to drill closely adjacent blastholes along the designed tunnel excavation contour line. These blastholes are not filled with explosives. Then, depending on the distance from the free surface, one or several rows of blastholes are drilled and loaded with explosives for blasting. Due to the existence of dense and adjacent blastholes, the transmission and expansion of the explosion stress wave and cracks when other blastholes explode are separated, so that the rock mass is cut along the weak surface, thus forming a flat rock wall. Although this technology can achieve better smooth blasting effect, it is rarely used in practice due to the high drilling cost caused by the large drilling workload. (2) The pre-splitting blasting method is to drill parallel and dense blastholes on the excavation contour line, use uncoupled charges or load low-power explosives and detonate them before other blastholes. When the spacing, number and charge structure of the blastholes on the contour line are appropriate, after blasting, interconnected cracks will be formed between the blastholes and they will be separated from the original rock. After that, other blastholes will be blasted. Since cracks have been formed on the contour line, the blasting of other blastholes will not cause damage to the surrounding rock mass, thus forming a smooth and flat wall surface. Although pre-splitting blasting can play a good vibration isolation role, it is only suitable for hard rock with relatively intact rock mass, medium-deep holes and deep holes due to the large drilling workload and high drilling accuracy requirements and the need to use special blasting equipment. (3) The smooth blasting method is to arrange dense blastholes along the excavation boundary, adopt radial uncoupled axial continuous charging or load low-power explosives, and detonate after the main blasting area to form a blasting operation with a smooth contour surface; however, the radial uncoupled axial continuous charging of the existing smooth blasting method not only requires accurate calculation and adjustment of the uncoupling coefficient according to the specific geological conditions and blasting requirements, but also leads to poor blasting effect if the uncoupling coefficient is improperly selected. For example, although the increase of the radial uncoupling coefficient can effectively reduce the intensity of the blasting seismic wave and thus reduce the blasting hazard, if the radial uncoupling coefficient is too large, the effective stress of the unit near the explosive section will be too low, which will affect the penetration of the cracks and reduce the blasting effect.
[0005] Therefore, how to reduce the hazards of blasting vibration while ensuring the effect of smooth blasting is one of the technical problems that need to be solved urgently in uncoupled smooth blasting. Summary of the invention
[0006] In view of the deficiencies in the prior art, the present invention provides a novel uncoupled smooth surface blasting method with low explosive consumption, small blasting vibration hazard, high construction efficiency and good smooth surface blasting effect.
[0007] The present invention is implemented in this way: including blasthole design, parameter design, blasthole arrangement, powder bag making, charge filling, blasting, vibration monitoring, and finishing steps, the specific contents are as follows: A. Blast hole design: a row of dense peripheral holes is arranged at the junction of the tunnel excavation working face and the surrounding rock retention area, and slot holes and auxiliary holes are arranged inside the peripheral holes; B. Parameter design: design the parameters of the peripheral holes and the charge structure; C. Blast hole arrangement: Draw a blast hole arrangement diagram, and arrange the peripheral holes, slot holes, and auxiliary holes according to the blast hole arrangement diagram; D. Cartridge production: According to the parameter design, axial and radial uncoupled charges are used to produce peripheral hole cartridges, and axial continuous charges are used to produce other hole cartridges; E. Charge and fill: according to the parameter design, the prepared peripheral hole charge packs are respectively filled in the top hole and the auxiliary hole of the peripheral hole, and the other hole charge packs are respectively filled in the corresponding peripheral hole bottom hole, the groove hole and the auxiliary hole, and ensure that each charge pack is sent to the bottom of the blast hole; F. Blasting: Connect the blasting network and check it, then use the half-second delay blasting network to blast the slot holes and auxiliary holes from inside to outside first, and then the surrounding holes; G. Vibration monitoring: Arrange blasting vibration testers at equal distances outside the blasting source, collect blasting vibration velocities in three mutually perpendicular directions to monitor the magnitude of blasting vibration, and determine the attenuation law of blasting vibration based on the vibration data; H. Finishing: Confirm the safety of the working surface, check whether there are blind shots and residual explosives, and confirm the blasting effect of the smooth surface.
[0008] Furthermore, the parameter design of the peripheral holes in step B includes the peripheral hole diameter d b , Peripheral hole spacing E , the minimum resistance line of the peripheral hole W , Peripheral hole density coefficient m , peripheral hole charge concentration q l , radial component of initial stress on the peripheral hole wall p r and tangential component p θ The design of the charge structure includes the radial uncoupling coefficient K d and axial uncoupling coefficient K l .
[0009] Furthermore, the peripheral hole spacing E =10 d b ~20 d b , the minimum resistance line of the peripheral hole W =10 d b ~25 db and W>E , the peripheral hole density coefficient m =0.8~1.0, the peripheral hole charge concentration q l The initial stress of the peripheral hole wall is between the dynamic tensile strength of the rock and the initial stress of the rock emulsion explosive. and dynamic compressive strength S C between.
[0010] Furthermore, in order to ensure the effect of smooth blasting, the initial stress acting on the blasthole wall needs to be greater than the dynamic tensile strength of the rock mass and less than the compressive strength of the rock mass. Therefore, the radial component of the initial stress on the peripheral hole wall is p r and tangential component p θ Calculated by the following formula: Where: K D It is the strength increase factor of rock under dynamic load conditions; S C The compressive strength of the rock mass can be approximately equal to the uniaxial compressive strength; K α is the stress concentration factor in the direction of the blasthole line, which is related to the blasthole diameter and hole spacing; The dynamic tensile strength of the rock mass is approximately equal to the static tensile strength of the rock. S t ,Right now .
[0011] Furthermore, the radial uncoupling coefficient K d = d b / d, where d is the diameter of the medicine roll filled in the peripheral hole; the axial uncoupling coefficient K l Calculated by the following formula: Where: n is the pressure enhancement coefficient of gas acting on the rock wall; λ is the ratio of the tangential stress component to the radial stress component, which can be expressed by the formula to seek; ρ 0 is the density of explosives; D is the detonation velocity of explosives; K d 6 is the radial uncoupling coefficient.
[0012] Furthermore, in the step D, the top holes and auxiliary holes of the peripheral holes are manufactured in the form of axially and radially uncoupled charge. According to the designed charge amount and axial uncoupling coefficient of the corresponding single hole, the charge rolls are connected by detonating cords to ensure the axial charge roll spacing to manufacture the charge rolls of the peripheral holes; at the same time, the charge packs of the bottom holes of the peripheral holes, the groove holes, and the auxiliary holes are manufactured in the form of axially continuous charge.
[0013] Furthermore, the diameter of the peripheral hole in step E is d b The diameter of the medicine roll is 50mm. d The material of the explosive is No. 1 rock emulsion explosive of 32mm. The depth of the peripheral hole is 3m. The top hole in the peripheral hole adopts a 2-1-1 structure from the inside to the outside to form a drug bag with 4 sections of drug rolls. The total length of the drug roll is 1.2m, the charge is 1.2kg, and the filling length is 0.5m; the auxiliary hole in the peripheral hole adopts a 2-1-1-1 structure from the inside to the outside to form a drug bag with 5 sections of drug rolls. The total length of the drug roll is 1.5m, the charge is 1.5kg, and the filling length is 0.5m; the bottom hole in the peripheral hole adopts an axially coupled drug bag formed by 9 sections of drug rolls from the inside to the outside, with a total length of 2.7m, a charge of 2.7kg, and no filling.
[0014] Furthermore, in the step F, the slot holes and auxiliary holes are blasted first, then the peripheral holes on the two sides are blasted, and finally the peripheral holes on the top are blasted; wherein, the detonation time of the auxiliary holes and the peripheral holes on the two sides differs by one segment, and the detonation time of the peripheral holes on the two sides and the peripheral holes on the top differs by one segment.
[0015] Furthermore, in the G step, the X direction of the blasting vibration tester points in the direction of the explosion center distance, the Y direction points in the radial direction of the explosion center, and the Z direction is perpendicular to the X and Y planes and vertically upward.
[0016] Furthermore, during the on-site installation of the blasting vibration tester, the ground is first leveled with cement to ensure that the sensor of the blasting vibration tester is placed on a horizontal surface, and then the vibration velocity sensor of the blasting vibration tester is fixed to the cement ground with plaster.
[0017] The beneficial effects of the present invention are: 1. The present invention is based on the study of the tunnel light explosion layer and the peripheral holes after the slot holes and auxiliary holes are blasted. The top hole and the auxiliary hole of the peripheral hole jointly adopt the radial and axial uncoupled charging structure, which can not only reduce the blasting charge of the peripheral holes, but also the radial uncoupled charging structure has a radial coupling medium, so that the explosion gas and the explosion shock wave generated during the explosion will not directly act on the blast hole wall, but first compress the uncoupled medium, and then transfer energy to the rock through the coupling medium. In this process, the peak value of the shock wave is reduced, and the energy can be evenly distributed on the blast hole wall, so that the crushing area becomes smaller; the axial uncoupled charging structure The structure can strengthen the control over the blasting action and improve the blasting effect by reducing the peak blasting pressure and prolonging the blasting time due to the air-interval charging. By adopting the combined charging structure, while ensuring the blasting effect, the calculation accuracy and adjustment requirements of the uncoupling coefficient can be reduced, and the peak pressure on the hole wall after the explosives are detonated can be significantly reduced to reduce the damage to the surrounding rock. While improving the smooth blasting effect, it effectively controls the impact of blasting vibration on the surrounding rock engineering, reduces the cost of subsequent reinforcement and support, makes the blasting operation safer, more economical and environmentally friendly, and has extremely high engineering application value.
[0018] 2. The axially discontinuous explosive rolls in the peripheral hole charging structure of the present invention are connected by detonating cords, and the process of first making the medicine bag and then loading and filling is adopted, so that during the construction process, the detonating cord and the medicine roll can be connected to form a medicine bag according to the designed charging parameters, and then transported to the working surface for loading and filling. Compared with the on-site production and filling method, the charging difficulty and charging time can be reduced, thereby improving the construction efficiency. Moreover, the structure of connecting the medicine rolls with detonating cords can also ensure that the medicine rolls form stable detonation, reducing the hazards of blind shots and explosion refusal.
[0019] In summary, the present invention has the characteristics of low explosive consumption, small blasting vibration hazard, high construction efficiency and good smooth blasting effect. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 is a blasthole arrangement diagram of Example 1 of the present invention, Figure 2 Schematic diagram of the peripheral hole charging structure of Example 1 of the present invention, In the figure: Figure 1 The numbers in the brackets correspond to the sections of the detonators in the holes: 1-peripheral hole, 2-charge roll, 3-detonating cord, 4-gun mud, 5-hole wall, 6-groove hole, 7-auxiliary hole, 8-groove hole. DETAILED DESCRIPTION
[0021] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited in any way. Any changes or improvements made based on the teachings of the present invention belong to the protection scope of the present invention.
[0022] like Figure 1 and 2 As shown, the present invention includes blasthole design, parameter design, blasthole arrangement, powder bag making, charge filling, blasting, vibration monitoring, and finishing steps, and the specific contents are as follows: A. Blast hole design: a row of dense peripheral holes is arranged at the junction of the tunnel excavation working face and the surrounding rock retention area, and slot holes and auxiliary holes are arranged inside the peripheral holes; B. Parameter design: design the parameters of the peripheral holes and the charge structure; C. Blast hole arrangement: Draw a blast hole arrangement diagram, and arrange the peripheral holes, slot holes, and auxiliary holes according to the blast hole arrangement diagram; D. Cartridge production: According to the parameter design, axial and radial uncoupled charges are used to produce peripheral hole cartridges, and axial continuous charges are used to produce other hole cartridges; E. Charge and fill: according to the parameter design, the prepared peripheral hole charge packs are respectively filled in the top hole and the auxiliary hole of the peripheral hole, and the other hole charge packs are respectively filled in the corresponding peripheral hole bottom hole, the groove hole and the auxiliary hole, and ensure that each charge pack is sent to the bottom of the blast hole; F. Blasting: Connect the blasting network and check it, then use the half-second delay blasting network to blast the slot holes and auxiliary holes from inside to outside first, and then the surrounding holes; G. Vibration monitoring: Arrange blasting vibration testers at equal distances outside the blasting source, collect blasting vibration velocities in three mutually perpendicular directions to monitor the magnitude of blasting vibration, and determine the attenuation law of blasting vibration based on the vibration data; H. Finishing: Confirm the safety of the working surface, check whether there are blind shots and residual explosives, and confirm the blasting effect of the smooth surface.
[0023] A good peripheral hole blasting effect must not only meet the requirements of regular tunnel contours and no under-excavation or over-excavation, but also ensure that the tunnel surrounding rock is less affected by blasting disturbances and does not produce obvious cracks, broken areas or hanging rock layers, so as to reduce support costs and safety hazards. There are generally two methods for setting peripheral hole parameters, namely the empirical formula method and the theoretical calculation method: the empirical formula method has limitations in setting peripheral hole parameters, and largely does not consider the rock properties of the surrounding rock and the characteristics of explosives in the tunnel, while the parameters obtained by the simple theoretical calculation method are often quite different from the actual situation, making it difficult to apply to engineering practice. Combining the empirical formula method with the theoretical calculation method is an effective way to optimize the peripheral hole parameters.
[0024] The parameter design of the peripheral hole in step B includes the peripheral hole diameter d b , Peripheral hole spacing E , the minimum resistance line of the peripheral hole W , Peripheral hole density coefficient m, peripheral hole charge concentration q l , radial component of initial stress on the peripheral hole wall p r and tangential component p θ The design of the charge structure includes the radial uncoupling coefficient K d and axial uncoupling coefficient K l .
[0025] The parameter design of the peripheral holes in step B is calculated by the following formula: Where: λ is the ratio of the tangential stress component to the radial stress component, λ=μ / (1-μ), where μ is the Poisson's ratio of the rock; S t is the static tensile strength of rock; a is the stress wave attenuation index; p k is the critical pressure; p 0 is the initial stress of the explosive gas; r is the adiabatic index; k is the entropy index; K d is the radial uncoupling coefficient; K l is the axial uncoupling coefficient; Since the blasting sequence of the peripheral holes is later than that of the slot holes and auxiliary holes, the blasting conditions are similar to open-pit step blasting. Therefore, the minimum resistance line of the peripheral holes can be calculated using the Haorou formula. W :
[0026] Where: q b The charge amount of a single hole for the peripheral holes can be calculated based on the charge concentration; l b is the peripheral hole depth; c is the explosion coefficient; Since the theoretical value of charge concentration is closely related to the characteristics and charge structure of the explosive, the charge concentration of the peripheral holes is q l It can be calculated according to the following formula: Where: ρ 0 is the density of explosive; d c is the diameter of the medicine roll; Kl is the axial uncoupling coefficient; K d is the radial uncoupling coefficient.
[0027] The depth of the blasthole in step B is generally determined by the type of equipment of the underground drilling rig. Usually, the depth of the peripheral holes and auxiliary holes is 3000 mm, and the depth of the slot holes is 3200 mm.
[0028] The peripheral hole spacing E =10 d b ~20 d b , the minimum resistance line of the peripheral hole W =10 d b ~25 d b and W>E , the peripheral hole density coefficient m =0.8~1.0, the peripheral hole charge concentration q l The initial stress of the peripheral hole wall is between the dynamic tensile strength of the rock and the initial stress of the rock emulsion explosive. and dynamic compressive strength S C between.
[0029] In order to ensure the effect of smooth blasting, the initial stress acting on the blasthole wall needs to be greater than the dynamic tensile strength of the rock mass and less than the compressive strength of the rock mass. Therefore, the radial component of the initial stress on the peripheral hole wall is p r and tangential component p θ Calculated by the following formula: Where: K D is the strength increase factor of rock under dynamic load conditions. K D =9~11; S C The compressive strength of the rock mass can be approximately equal to the uniaxial compressive strength; K α It is the stress concentration factor in the direction of the blasthole line, which is related to the blasthole diameter and hole spacing. When the hole spacing is greater than 10 times the blasthole diameter, K α =2; The dynamic tensile strength of the rock mass is approximately equal to the static tensile strength of the rock. St ,Right now .
[0030] The radial uncoupling coefficient K d = d b / d, where d is the diameter of the medicine roll filled in the peripheral hole; the axial uncoupling coefficient K l Calculated by the following formula: Where: n is the pressure enhancement coefficient of gas acting on the rock wall. n =10; λ is the ratio of the tangential stress component to the radial stress component, which can be expressed by the formula to seek; ρ 0 is the density of explosives; D is the detonation velocity of explosives; K d 6 is the radial uncoupling coefficient.
[0031] In the step C, a slotting hole 6 is set in the middle of the tunnel excavation working face surrounded by the peripheral holes and the retained surrounding rock area. The slotting hole 6 has the functions of stress concentration and providing compensation space, so as to obtain a better slotting effect.
[0032] In the above-mentioned step D, the top holes and auxiliary holes of the peripheral holes are manufactured in the form of axially and radially uncoupled charge. According to the designed charge amount and axial uncoupling coefficient of the corresponding single hole, the charge rolls are connected by detonating cord to ensure the axial charge roll spacing to manufacture the charge rolls of the peripheral holes. At the same time, the charge packs of the bottom holes of the peripheral holes, the groove holes and the auxiliary holes are manufactured in the form of axial continuous charge.
[0033] In the step D, the explosive packs of the bottom holes of the peripheral holes, the slot holes and the auxiliary holes are loaded in an axial continuous charge form, generally 7 to 8 rolls of No. 1 rock emulsion explosive.
[0034] The diameter of the peripheral hole in step E d b The diameter of the medicine roll is 50mm. dThe material of the explosive is No. 1 rock emulsion explosive of 32mm. The depth of the peripheral hole is 3m. The top hole in the peripheral hole adopts a 2-1-1 structure from the inside to the outside to form a drug bag with 4 sections of drug rolls. The total length of the drug roll is 1.2m, the charge is 1.2kg, and the filling length is 0.5m; the auxiliary hole in the peripheral hole adopts a 2-1-1-1 structure from the inside to the outside to form a drug bag with 5 sections of drug rolls. The total length of the drug roll is 1.5m, the charge is 1.5kg, and the filling length is 0.5m; the bottom hole in the peripheral hole adopts an axially coupled drug bag formed by 9 sections of drug rolls from the inside to the outside, with a total length of 2.7m, a charge of 2.7kg, and no filling.
[0035] In step E, No. 2 rock emulsion explosive can also be used; the energy can be converted based on the relationship between the mass of the explosive and its detonation energy. E The energy of No. 1 and No. 2 explosives is E 2, the dosage conversion relationship is: M 2= M 1*( E 1 / E 2), where M 1 and M 2 are the amounts of No. 1 and No. 2 explosives respectively.
[0036] In the step F, the slot holes and auxiliary holes are blasted first, then the peripheral holes on the two sides are blasted, and finally the peripheral holes on the top are blasted; wherein, the detonation time of the auxiliary holes and the peripheral holes on the two sides differs by one segment, and the detonation time of the peripheral holes on the two sides differs by one segment from the peripheral holes on the top.
[0037] In the G step, the X direction of the blasting vibration tester points to the direction of the explosion center distance, the Y direction points to the radial direction of the explosion center, and the Z direction is perpendicular to the X and Y planes and vertically upward.
[0038] During the on-site installation of the blasting vibration tester, the ground is first leveled with cement to ensure that the sensor of the blasting vibration tester is placed on a horizontal surface, and then the vibration velocity sensor of the blasting vibration tester is fixed to the cement ground with plaster.
[0039] Example 1 The underground uncoupled smooth blasting in a copper mine in Yunnan Province is as follows: S100: a row of dense peripheral holes 1 is arranged at the junction of the tunnel excavation working face and the surrounding rock retention area, and a slot hole 8 and an auxiliary hole 7 are arranged inside the peripheral hole 1; S200: Design the parameters of the peripheral hole 1 and the charge structure: S210: Peripheral hole diameter d b: According to the rock conditions and the requirements of the drilling equipment, the blastholes of the peripheral holes 1 are all selected with a diameter of 50 mm and are drilled perpendicular to the working face.
[0040] S220: Peripheral hole spacing E :Peripheral hole spacing E and peripheral hole diameter d b In a certain proportional relationship, generally the peripheral hole spacing E In 10 d b ~20 d b Therefore, the peripheral hole spacing here E The range should be between 0.5 and 1 m. The peripheral hole spacing is calculated according to the formula E It is 0.62m.
[0041] S230: Peripheral hole minimum resistance line W :The minimum resistance line of the peripheral hole W Peripheral hole spacing E The reason is that the collapse of the light explosion layer must occur after the peripheral hole 1 penetrates the crack. Only in this way can the basic regularity of the tunnel contour be guaranteed. d b Closely related, generally around 10 d b ~25 d b Therefore, the minimum resistance line of the peripheral hole here W It should be controlled between 0.5~1.25m and larger than the surrounding hole spacing E Calculate the minimum resistance line of the peripheral hole according to the following formula W It is 0.92.
[0042]
[0043] Where: q b The charge amount of a single hole for the peripheral holes can be calculated based on the charge concentration; l b is the depth of the peripheral hole, which is 3m; c is the explosion coefficient, take 0.25kg / m 3 .
[0044] S240: Peripheral hole density coefficient m : Peripheral hole density coefficient m It is an important parameter for smooth blasting. Generally, when the rock in the tunnel is hard rock, the peripheral hole density coefficient m It can be between 0.8 and 1.0.
[0045] S250: Peripheral hole charge concentrationq l :Peripheral hole charge concentration q l It is the ratio of the charge mass in a single peripheral hole 1 to the depth of the peripheral hole, and is an important parameter for describing the charge density of peripheral hole 1. According to mining practical experience, the charge concentration of peripheral hole 1 of No. 1 rock emulsion explosive under hard rock conditions is q l It can be between 0.2~0.35kg / m. q l The calculation is 0.22~0.27.
[0046] S260: Radial component of initial stress on hole wall 5 of peripheral hole 1 p r and tangential component p θ .
[0047] The explosion stress wave and the explosion gas generated by the explosion of the cartridge 2 act on the rock of the hole wall 5 of the surrounding hole 1. In order to obtain a good light explosion effect, the initial stress acting on the hole wall 5 is between the dynamic tensile strength of the rock. and dynamic compressive strength S C Therefore, it can be expressed numerically as the following formula: Where: K D is the strength increase factor of rock under dynamic load conditions, K D =9~11; S C The compressive strength of the rock mass can be approximately equal to the uniaxial compressive strength; K α It is the stress concentration factor in the direction of the blasthole line, which is related to the blasthole diameter and hole spacing. When the hole spacing is greater than 10 times the blasthole diameter, K α =2; The dynamic tensile strength of the rock mass is approximately equal to the static tensile strength of the rock. S t ,Right now .
[0048] S270: Radial uncoupling coefficient K d and axial uncoupling coefficient K l .
[0049] Radial uncoupling coefficient K d=D / d, where d is the diameter of the medicine roll 2 filled in the peripheral hole 1, here is K d =1.56.
[0050] Axial uncoupling coefficient K l Calculated by the following formula: Where: n is the pressure enhancement coefficient of gas acting on the rock wall, generally = 10; λ is the ratio of the tangential stress component to the radial stress component, which can be expressed by the formula to seek; ρ 0 is the density of explosives; D is the detonation velocity of explosives; K d 6 is the radial uncoupling coefficient.
[0051] Through empirical formula and theoretical calculation methods, the relevant smooth blasting parameters of the peripheral holes are obtained, and the calculation results are summarized in Table 1. The results of the two methods are combined with the actual situation of the mine to determine the optimized smooth blasting parameters, and the actual values are applied to the field blasting test.
[0052]
[0053] S300: Draw a blasthole layout diagram, and arrange the peripheral holes 1, the slot holes 8, and the auxiliary holes 7 according to the blasthole layout diagram (e.g. Figure 1 as shown).
[0054] S400: According to the parameter design, axial and radial uncoupled charges are used to make peripheral hole charges, and the detonating cord 3 and the charge roll 2 are connected as required to make charges for the peripheral hole 1; axial continuous charges are used to make charges for other holes; S500: according to the parameter design, the prepared peripheral hole powder packs are respectively filled in the top hole and the side hole of the peripheral hole 1, and the other hole powder packs are respectively filled in the corresponding peripheral hole bottom hole and the groove hole 8, and the auxiliary hole 7, and ensure that each powder pack is sent to the bottom of the blast hole; like Figure 2 As shown, the peripheral hole diameter D The diameter of the medicine roll 2 is 50mm. dThe diameter of the No. 1 rock emulsion explosive is 32mm (usually the diameter of the No. 1 rock emulsion explosive roll is 32~40mm and the length is 200~300mm. This patent takes the No. 1 rock emulsion explosive used in the mine as an example, which has a length of 300mm, a diameter of 32mm, and a single roll of 0.3kg. Other sizes of explosives can be converted using the equal volume method or the explosive mass.), the depth of the peripheral hole 1 is 3m, and the top hole in the peripheral hole 1 adopts a 2-1-1 structure from the inside to the outside to install a total of 4 sections of the roll 2-shaped The total length of the medicine roll 2 is 1.2m, the charge is 1.2kg, and the length of the gun mud 4 is 0.5m; the single hole of the auxiliary hole in the peripheral hole 1 adopts a 2-1-1-1 structure from the inside to the outside to form a medicine bag with 5 sections of medicine roll 2, the total length of the medicine roll 2 is 1.5m, the charge is 1.5kg, and the length of the gun mud 4 is 0.5m; the single hole of the bottom hole in the peripheral hole 1 adopts 9 sections of medicine roll 2 from the inside to the outside to form an axially coupled medicine bag, the total length of the medicine roll 2 is 2.7m, the charge is 2.7kg, and there is no filling.
[0055] S600: First blast the slot holes and auxiliary holes, then blast the peripheral holes on both sides, and finally blast the peripheral holes on the top; among them, the detonation time between the auxiliary holes and the peripheral holes on both sides is one stage different, and the detonation time between the peripheral holes on both sides and the peripheral holes on the top is one stage different. In order to reduce the blasting vibration, the auxiliary holes and the peripheral holes on both sides, as well as the peripheral holes on both sides and the peripheral holes on the top, use a half-second delay blasting network. The blasting design delay time of the blasthole is as follows: Figure 1 As shown, 10 sections of half-second delay electronic detonators are required, namely section 1 (0s), section 2 (0.5s), section 3 (1s), section 4 (1.5s), section 5 (2.0s), section 6 (2.5s), section 7 (3s), section 8 (3.6s), section 9 (4.5s) and section 10 (5.5s).
[0056] S700: Arrange blasting vibration testers at equal distances outside the blasting source to collect blasting vibration velocities in three mutually perpendicular directions to monitor the magnitude of blasting vibration.
[0057] Specifically, during the on-site installation process, the ground is first leveled with cement to ensure that the sensor of the blasting vibration tester is placed on a horizontal plane, and then the vibration velocity sensor of the blasting vibration tester is fixed to the cement floor with plaster to ensure the stability of the monitoring data transmission. When arranging the blasting vibration tester, the X direction points to the direction of the explosion center, the Y direction points to the radial direction of the explosion center, and the Z direction is perpendicular to the X and Y planes and vertically upward. The on-site monitoring of blasting vibration mainly selects measuring points that are close to the explosion source of the working face for research. According to the Sadowski formula: V = K ( Q / R m ) n , the particle velocity of blasting vibrationV As the distance from the explosion source to the monitoring point increases R The increase decays exponentially. The range of measuring points is selected according to the maximum single-shot charge and the vibration speed allowed by the "Safety Regulations for Blasting". 4 to 5 measuring points within the measuring range can reliably reflect the vibration law. Therefore, in this embodiment, a total of 4 blasting vibration testers are arranged along the tunnel. The first measuring point is selected at 50m in consideration of equipment safety, and the other measuring points are selected at intervals of 50m. The distances between each instrument arrangement point and the blasting center are 50m, 100m, 150m, and 200m, respectively, to make the measured vibration attenuation law more reliable.
[0058] S800: Confirm the safety of the working surface, check whether there are blind shots and residual explosives, and confirm the blasting effect of the smooth surface.
[0059] Based on smooth blasting, this embodiment comprehensively considers the geological environment of the engineering site and the optimization of the blasting design, so that the over-excavation and under-excavation around the tunnel can be effectively controlled. Especially when the surrounding rock properties are poor, the light blasting effect of the new uncoupled smooth blasting method adopted in this embodiment is significantly better than that of the traditional smooth blasting, and the semi-pore rate formed by the excavation is high, the wall surface is complete, and the over-excavation and under-excavation are small. The method of connecting the axially spaced charge rolls with detonating cords can ensure the stability of the detonation propagation and significantly reduce the blasting problems of blind shots and residual charge.
[0060] This embodiment reversely infers the maximum single-shot charge during tunnel excavation based on the maximum vibration speed allowed by the national standards for engineering buildings near the blast source (such as tunnels and retained pillars). At the same time, the axial-radial uncoupled charge method designed in this embodiment reduces the charge by 3 rolls (i.e., 0.9 kg) compared with the traditional axial uncoupled charge. According to the blasting design, it can be seen that the number of salvo holes in the peripheral holes is the largest (there are 11 holes with a detonator section number of 10, including 9 top holes and 2 bottom holes). The charge structure designed by this patent can reduce the maximum single-shot charge from 23.1 kg to 15 kg, thereby reducing the impact of blasting vibration on surrounding rock engineering.
[0061] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.
Claims
1. A novel uncoupled smooth blasting method, characterized in that: It includes blasthole design, parameter design, blasthole arrangement, powder bag making, charge filling, blasting, vibration monitoring, and finishing steps. The specific contents are as follows: A. Blast hole design: a row of dense peripheral holes is arranged at the junction of the tunnel excavation working face and the surrounding rock retention area, and slot holes and auxiliary holes are arranged inside the peripheral holes; B. Parameter design: design the parameters of the peripheral holes and the charge structure; C. Blast hole arrangement: Draw a blast hole arrangement diagram, and arrange the peripheral holes, slot holes, and auxiliary holes according to the blast hole arrangement diagram; D. Cartridge production: According to the parameter design, axial and radial uncoupled charges are used to produce peripheral hole cartridges, and axial continuous charges are used to produce other hole cartridges; E. Charge and fill: according to the parameter design, the prepared peripheral hole charge packs are respectively filled in the top hole and the auxiliary hole of the peripheral hole, and the other hole charge packs are respectively filled in the corresponding peripheral hole bottom hole, the groove hole and the auxiliary hole, and ensure that each charge pack is sent to the bottom of the blast hole; F. Blasting: Connect the blasting network and check it, then use the half-second delay blasting network to blast the slot holes and auxiliary holes from inside to outside first, and then the surrounding holes; G. Vibration monitoring: Arrange blasting vibration testers at equal distances outside the blasting source, collect blasting vibration velocities in three mutually perpendicular directions to monitor the magnitude of blasting vibration, and determine the attenuation law of blasting vibration based on the vibration data; H. Finishing: Confirm the safety of the working surface, check whether there are blind shots and residual explosives, and confirm the blasting effect of the smooth surface.
2. The novel uncoupled smooth blasting method according to claim 1 is characterized in that: The parameter design of the peripheral hole in step B includes the peripheral hole diameter d b , Peripheral hole spacing E , the minimum resistance line of the peripheral hole W , Peripheral hole density coefficient m , peripheral hole charge concentration q l , radial component of initial stress on the peripheral hole wall p r and tangential component p θ The design of the charge structure includes the radial uncoupling coefficient K d and axial uncoupling coefficient K l .
3. The novel uncoupled smooth blasting method according to claim 2 is characterized in that: The peripheral hole spacing E =10 d b ~20 d b , the minimum resistance line of the peripheral hole W =10 d b ~25 d b and W>E , the peripheral hole density coefficient m =0.8~1.0, the peripheral hole charge concentration q l The initial stress of the peripheral hole wall is between the dynamic tensile strength of the rock and the initial stress of the rock emulsion explosive. and dynamic compressive strength S C between.
4. The novel uncoupled smooth blasting method according to claim 3 is characterized in that: In order to ensure the effect of smooth blasting, the initial stress acting on the blasthole wall needs to be greater than the dynamic tensile strength of the rock mass and less than the compressive strength of the rock mass. Therefore, the radial component of the initial stress on the peripheral hole wall is p r and tangential component p θ Calculated by the following formula: Where: K D It is the strength increase factor of rock under dynamic load conditions; S C The compressive strength of the rock mass can be approximately equal to the uniaxial compressive strength; K α is the stress concentration factor in the direction of the blasthole line, which is related to the blasthole diameter and hole spacing; The dynamic tensile strength of the rock mass is approximately equal to the static tensile strength of the rock. S t ,Right now .
5. The novel uncoupled smooth blasting method according to claim 4 is characterized in that: The radial uncoupling coefficient K d = d b / d, where d is the diameter of the medicine roll filled in the peripheral hole; the axial uncoupling coefficient K l Calculated by the following formula: Where: n is the pressure enhancement coefficient of gas acting on the rock wall; λ is the ratio of the tangential stress component to the radial stress component, which can be expressed by the formula to obtain; ρ 0 is the density of explosives; D is the detonation velocity of explosives; K d 6 is the radial uncoupling coefficient.
6. The novel uncoupled smooth blasting method according to claim 5 is characterized in that: In the above-mentioned step D, the top holes and auxiliary holes of the peripheral holes are manufactured in the form of axially and radially uncoupled charge. According to the designed charge amount and axial uncoupling coefficient of the corresponding single hole, the charge rolls are connected by detonating cord to ensure the axial charge roll spacing to manufacture the charge rolls of the peripheral holes. At the same time, the charge packs of the bottom holes of the peripheral holes, the groove holes and the auxiliary holes are manufactured in the form of axial continuous charge.
7. The novel uncoupled smooth blasting method according to claim 6 is characterized in that: The diameter of the peripheral hole in step E d b The diameter of the medicine roll is 50mm. d The material of the explosive is No. 1 rock emulsion explosive of 32mm. The depth of the peripheral hole is 3m. The top hole in the peripheral hole adopts a 2-1-1 structure from the inside to the outside to form a drug bag with 4 sections of drug rolls. The total length of the drug roll is 1.2m, the charge is 1.2kg, and the filling length is 0.5m; the auxiliary hole in the peripheral hole adopts a 2-1-1-1 structure from the inside to the outside to form a drug bag with 5 sections of drug rolls. The total length of the drug roll is 1.5m, the charge is 1.5kg, and the filling length is 0.5m; the bottom hole in the peripheral hole adopts an axially coupled drug bag formed by 9 sections of drug rolls from the inside to the outside, with a total length of 2.7m, a charge of 2.7kg, and no filling.
8. The novel uncoupled smooth blasting method according to claim 6 is characterized by: In the step F, the slot holes and auxiliary holes are blasted first, then the peripheral holes on the two sides are blasted, and finally the peripheral holes on the top are blasted; wherein, the detonation time of the auxiliary holes and the peripheral holes on the two sides differs by one segment, and the detonation time of the peripheral holes on the two sides differs by one segment from the peripheral holes on the top.
9. The novel uncoupled smooth blasting method according to claim 6 is characterized in that: In the G step, the X direction of the blasting vibration tester points to the direction of the explosion center distance, the Y direction points to the radial direction of the explosion center, and the Z direction is perpendicular to the X and Y planes and vertically upward.
10. The novel uncoupled smooth blasting method according to claim 9 is characterized in that: During the on-site installation of the blasting vibration tester, the ground is first leveled with cement to ensure that the sensor of the blasting vibration tester is placed on a horizontal surface, and then the vibration velocity sensor of the blasting vibration tester is fixed to the cement ground with plaster.