Tunnel blasting vibration control method based on explosive density partition

Abstract

The invention discloses a tunnel blasting vibration control method based on explosive density partitioning, which comprises the following steps: (1) carrying out conventional tunnel blasting design and drilling and blasting operation, and carrying out blasting vibration monitoring; (2) fitting a tunnel blasting vibration propagation attenuation formula and calculating tunnel blasting safety allowable explosive quantity; (3) determining the blast hole adjusting explosive load by combining the conventional unit consumption and the safe allowable explosive load; (4) keeping the explosive energy consistent and the charging length of the blast hole unchanged, and calculating the adjustment density of the explosive filled in the blast hole after the explosive charging amount is adjusted; (5) density-adjustable explosives are configured, and tunnel blast hole charging density partitioning is achieved; and (6) checking according to the steps (1) and (2) to realize that the blasting vibration is within a safe allowable range after explosive density partitioning. According to the method, the tunnel blasting vibration is effectively controlled on the premise that tunnel blasting hole net parameters and delay setting are not changed and the construction efficiency is not affected by filling the explosive with the adjustable density.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel blasting, and more particularly to a tunnel blasting vibration control method based on explosive density zoning. Background Art

[0002] During the drilling and blasting tunnel excavation process, blasting vibration may have a harmful effect on nearby buildings (structures). Therefore, for drilling and blasting tunnels under construction with important buildings (structures) distributed around them, tunnel blasting vibration control has always been a difficult and important issue of general concern. For example, railway tunnel blasting close to existing lines often has to adopt a "short advance, weak blasting" construction plan due to very strict requirements for blasting vibration control. Some tunnels in complex environments can only be excavated using non-blasting methods with low construction efficiency. It can be seen that there is a certain contradiction between traditional tunnel blasting vibration control and construction efficiency, and there is an urgent need for a blasting construction method that takes into account both blasting vibration control and construction efficiency.

[0003] In addition to the tunnel blasting vibration control method that sacrifices construction efficiency, the existing tunnel blasting vibration control methods include two main methods: slot blasting adjustment and blasting network optimization, such as CN110926288B-A method for optimizing the amount of charge for slot blasting in shallow buried tunnels considering the cavity effect, which controls the blasting vibration by adjusting the amount of charge for slot blasting. Considering that the free surface conditions of tunnel slot blasting are single and the clamping effect is strong, the blasting vibration induced by this is often the largest, and adjusting the slot blasting has become a major tunnel blasting vibration control method. However, the method of adjusting the slot blasting ignores the situation that the auxiliary holes and peripheral holes may cause large blasting vibrations, and cannot control the tunnel blasting vibration as a whole. In addition, this method changes the construction workers' habit of loading a fixed number of charge rolls according to the fixed blasthole design and networking in a fixed manner, which reduces the construction efficiency to a certain extent. With the popularization and application of electronic detonators, hole-by-hole or micro-difference detonation networks have become widely used blasting vibration control methods. However, due to the great differences in rock mass conditions in tunnel projects, it is difficult to determine the reasonable delay parameters of electronic detonators, and even if hole-by-hole or micro-difference detonation networks are used, the gain superposition phenomenon of blasting vibration is still frequent. It can be seen that CN110926288B only adjusts the amount of charge for slot blasting, ignoring the influence of auxiliary holes and peripheral holes, and it is difficult for construction workers to adapt to the dynamically changing slot blasting design, and the construction efficiency is easily affected; in addition, CN117553641A-mechanized charging technology is used for small-section tunnel straight-eye slot blasting method, which adjusts the control mode of slot blasting and detonates a whole circle of blastholes at one time, and the single-stage charge is large, which is not conducive to blasting vibration control, and there is also the problem of changing the working habits of construction workers.

[0004] Therefore, tunnel blasting vibration control is still a problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] The purpose of the present invention is to provide a tunnel blasting vibration control method based on explosive density zoning to address the shortcomings of existing tunnel blasting vibration control technology, so as to achieve effective control of tunnel blasting vibration without changing the tunnel blasting hole network parameters and detonator delay settings and without affecting the construction efficiency, and the method is suitable for tunnels with various complex geological conditions.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A tunnel blasting vibration control method based on explosive density zoning comprises the following steps:

[0008] (1) Conventional tunnel blasting design and drilling and blasting operations, and blasting vibration monitoring;

[0009] (2) Using the blasting vibration monitoring results, the tunnel blasting vibration propagation attenuation formula is regressed and fitted, and then the safe allowable explosive dosage for tunnel blasting is inferred;

[0010] (3) Determine the charge amount for adjusting the borehole based on the conventional unit consumption and the safe allowable charge amount;

[0011] (4) Keeping the explosive energy and the length of the blasthole charge consistent, calculate the adjusted density of the explosive filled in the blasthole after the charge amount is adjusted;

[0012] (5) Configure density-adjustable explosives to achieve tunnel blasthole charge density zoning;

[0013] (6) Check in accordance with steps (1) and (2) that the blasting vibration is within the safe allowable range after the explosive density is divided into zones.

[0014] The specific contents of each of the above steps are as follows:

[0015] Step (1) specifically includes: carrying out conventional tunnel blasting design, determining the explosive consumption range for blasting the tunnel slot holes, auxiliary holes and peripheral holes, and performing drilling and blasting operations according to the conventional design, carrying out blasting vibration monitoring during the conventional blasting process, and arranging no less than 5 blasting vibration monitoring points between the blasting source and the protected object at the tunnel face before blasting, and arranging at least 1 blasting vibration monitoring point at the protected object.

[0016] Step (2) is specifically: using the blasting vibration monitoring results in the horizontal radial, horizontal tangential and vertical directions to regress and fit the tunnel blasting vibration propagation attenuation formula in the horizontal radial, horizontal tangential and vertical directions:

[0017] V=K(Q 13 / R)α

[0018] In the formula, V is the blasting vibration velocity, Q is the single-stage charge, R is the distance from the blasting center, K and α are attenuation constants, where V is determined by the blasting vibration monitoring results, Q is determined according to the blasting design, R is obtained by on-site measurement, and K and α are determined by linear regression fitting;

[0019] The formula for safe charge dosage allowed for tunnel blasting is obtained from the above formula:

[0020] [Q]=R([V] / K) 3α , [V] is the blasting vibration safety control standard for the protected object, which is determined by the Blasting Safety Regulations (GB6722);

[0021] Substitute the distance R between the protected object and the blasting source of the slot holes, auxiliary holes and peripheral holes determined by on-site measurements into the above safe charge formula to obtain the allowable safe charge for blasting the slot holes, auxiliary holes and peripheral holes in the horizontal radial, horizontal tangential and vertical directions. To ensure the safety of the protected object, according to relevant specifications, the allowable safe charge for blasting the slot holes, auxiliary holes and peripheral holes is the minimum value calculated from the blasting vibration propagation attenuation formula in the horizontal radial, horizontal tangential and vertical directions.

[0022] Step (3) specifically comprises: under the condition that the tunnel blasting hole network parameters and the detonation network obtained in step (1) remain unchanged, in order to reduce the blasting vibration, the unit consumption q of the tunnel blasting slot holes, auxiliary holes and peripheral holes in step (1) is set to the lower limit of the given range of the specification and parameters, and according to Q 调 =qabH determines the adjusted charge of conventional density explosives for slot holes, auxiliary holes and peripheral holes, where a and b are the distance between blast holes and row spacing, H is the depth of the blast hole, and Q 调 Less than [Q].

[0023] Step (4) is specifically: based on the principle of consistent explosive energy, the charge length L and volume V of the slot hole, auxiliary hole and peripheral hole are kept unchanged, and the charge amount obtained in step (3) is adjusted according to ρ=kQ 调 / V calculates the adjusted density ρ of density-adjustable explosives filled in slot holes, auxiliary holes and peripheral holes. k is the conversion coefficient of the energy of explosives of different densities and is provided by the explosives manufacturer.

[0024] Step (5) specifically comprises: according to the calculation result of adjusting the density of explosives filled in the slot holes, auxiliary holes and peripheral holes, the explosives factory configures density-adjustable explosives of corresponding density, and respectively fills the slot holes, auxiliary holes and peripheral holes with density-adjustable explosives of different densities, so as to realize the charging density zoning of the slot holes, auxiliary holes and peripheral holes. In addition to filling the density-adjustable explosives of corresponding density in the charging process, the drilling, charging, filling, networking and detonating operations are completed according to the conventional drilling and blasting operation process. The charging density of each slot hole, auxiliary hole and peripheral hole area can be further refined according to the need of blasting vibration control according to steps (3) and (4) to cyclically refine the explosive density zoning.

[0025] Step (6) specifically comprises: carrying out tunnel blasting vibration monitoring according to the requirements in steps (1) and (2), verifying that the blasting vibration of the protected object after the explosive density zoning is within the safe allowable range, and after determining that the blasting vibration of the protected object is safe, testing the blasting effect after the explosive density zoning, if the blocks after blasting are relatively uniform and there are no large blocks, indicating that the blasting effect can be well achieved, then further reducing the charge density of the slot holes, auxiliary holes and peripheral holes according to a certain reduction ratio to achieve stricter blasting vibration control, when the block footage rate after blasting exceeds the specification requirements, the reduction ratio is calculated according to 0.8 to 0.9 based on the actual situation on site, wherein the degree of further reduction of the explosive density is determined according to the blasting effect, and if the blasting fragmentation effect just meets the specification requirements, the explosive density is not further reduced.

[0026] The present invention can adjust the explosives only by the filling density without changing the original tunnel blasting hole network parameters and the detonator delay setting, so as to form the explosive density partition in different blast holes and realize the effective control of tunnel blasting vibration, and its beneficial effects are as follows:

[0027] (1) The original tunnel blasting drilling depth is not changed, and the construction method of "short advance, weak blasting" is not adopted. Blasting vibration control is achieved under the condition of ensuring tunnel blasting advance, which solves the contradiction between traditional tunnel blasting vibration control and construction efficiency.

[0028] (2) The original tunnel blasting hole network parameters and detonator delay settings do not need to be changed, and the blasting management, technology and construction personnel do not need to change their original working mode. It is easy to be widely accepted by on-site construction units and management, technology and construction personnel, and does not require additional operation training, and does not affect the construction workers' construction mood and efficiency.

[0029] (3) The density of explosives can be adjusted by filling them, forming zones of explosive density in different blastholes, realizing effective control of tunnel blasting vibration, focusing the blasting vibration control on the precise control of the explosive energy source of a single blasthole, and being able to solve complex working conditions such as the interlacing of soft and hard surrounding rocks. It is suitable for different geological conditions and different blasthole conditions, has strong applicability, and can be widely extended to tunnel blasting vibration control.

[0030] (4) This method takes into account both blasting vibration control and blasting effect, and realizes effective blasting vibration control while satisfying the blasting effect. By lowering the density of explosives to the limit, it can detonate and save construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0032] Figure 1 The present invention is a schematic diagram of the implementation flow of a tunnel blasting vibration control method based on explosive density zoning.

[0033] Figure 2 This is a schematic diagram of conventional blasting design.

[0034] Figure 3 Schematic diagram of explosive density zoning for tunnel blasting. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] This embodiment is a railway tunnel under construction, and the important protection object is the existing line tunnel. The closest straight-line distance between the railway tunnel under construction and the existing line tunnel is about 20m. The existing line tunnel blasting and railway ancillary facilities and equipment have strict vibration control requirements, and the allowable blasting vibration speed is 2.0cm / s. At present, the closest distance between the tunnel face under construction and the existing line tunnel is about 30m, and the blasting vibration control is very difficult. A short-footage blasting scheme is adopted. In order to take into account the tunnel blasting construction progress and blasting vibration control, the method proposed in the present invention is used to control the blasting vibration of the tunnel under construction. The blasting vibration is strictly lower than 2.0cm / s, and the existing line tunnel is safe and stable.

[0037] The specific method of the present invention is about a tunnel blasting vibration control method based on explosive density zoning, and the schematic diagram of its implementation process is as follows: Figure 1 As shown, the following steps are included:

[0038] (1) Carry out conventional tunnel blasting design. According to the rock mass strength coefficient given by the design unit, the unit consumption of explosives for tunnel cutting holes and auxiliary holes is determined to be in the range of 1.6-1.8 kg / m by referring to relevant specifications and manuals. 3 1.5~1.6kg / m 3 The density of the wire charge for peripheral hole blasting is 350-400 g / m. The arrangement of blast holes and the detonation network are as follows: Figure 2 As shown in the figure (in the figure, slot hole 1, auxiliary hole 2, peripheral hole 3), follow the steps given in the relevant specifications and manuals to carry out Figure 2 The conventional design shown is used for drilling and blasting operations, and blasting vibration monitoring is carried out during the conventional blasting process. It is necessary to arrange five blasting vibration monitoring points in the tunnel to carry out blasting vibration propagation attenuation law tests, and arrange two monitoring points in the existing line tunnel to carry out blasting vibration monitoring of the protected object.

[0039] (2) Based on the blasting vibration monitoring data in the horizontal radial, horizontal tangential and vertical directions of each monitoring point, the horizontal radial, horizontal tangential and vertical vibration propagation attenuation formulas of the tunnel cut hole, auxiliary hole and peripheral hole blasting are regressed and fitted respectively:

[0040] V=K(Q 13 / R)α

[0041] The formula for safe charge dosage allowed for tunnel blasting is obtained from the above formula:

[0042] [Q]=R([V] / K) 3α , [V] is the blasting vibration safety control standard for the protected object, which is 2.0 cm / s in this embodiment.

[0043] The distances between the protected object and the blasting sources of the slot holes, auxiliary holes and peripheral holes are determined to be 35m, 32m and 30m respectively. The distances R between the protected object and the blasting sources of the slot holes, auxiliary holes and peripheral holes determined by on-site measurements are substituted into the above safe charge formula to obtain the safe charge allowed for blasting the slot holes, auxiliary holes and peripheral holes in the horizontal radial, horizontal tangential and vertical directions. To ensure the safety of the protected object, according to relevant specifications, the safe charge allowed for blasting the slot holes, auxiliary holes and peripheral holes is the minimum value calculated by the blasting vibration propagation attenuation formula in the horizontal radial, horizontal tangential and vertical directions. The safe charge allowed for blasting the slot holes, auxiliary holes and peripheral holes is 900g, 600g and 450g respectively.

[0044] (3) Under the condition that the tunnel blasting hole network parameters and detonation network remain unchanged, the unit consumption range of explosives for slot holes, auxiliary holes and peripheral holes in conventional tunnel blasting and the lower limit of the allowable safe amount of explosives are taken to determine the adjusted charge amount of the corresponding slot holes, auxiliary holes and peripheral holes. After adjustment, the charge amounts of the slot holes, auxiliary holes and peripheral holes are 800g, 500g and 300g respectively.

[0045] (4) Based on the principle of consistent explosive energy, the length of the charge in the slot holes, auxiliary holes and peripheral holes is kept unchanged. The adjusted charge amount of the slot holes and auxiliary holes is used as the basis for calculating the adjusted density of the explosives in the slot holes, auxiliary holes and peripheral holes. The density ρ of the explosives in the slot holes, auxiliary holes and peripheral holes is increased from the initial 1200kg / m 3 Adjusted to 1060kg / m 3 , 1000kg / m 3 、660kg / m 3 (like Figure 3 shown).

[0046] (5) According to the calculation results of the density adjustment of explosives in the slot holes, auxiliary holes and peripheral holes, the density-adjustable bulk emulsion explosives with corresponding density are configured to realize the charging density zoning of the slot holes, auxiliary holes and peripheral holes. The density zoning of explosives for tunnel blasting is as follows: Figure 3 Except for the bulk emulsion explosive with adjustable density of corresponding density in the charging process, the drilling, charging, filling, networking and detonation operations are completed according to the conventional drilling and blasting operation process.

[0047] (6) Carry out tunnel blasting vibration monitoring in accordance with the requirements of steps (1) and (2), and verify that the blasting vibration of the protected object after the explosive density division is less than 2.0 cm / s and is within the safe allowable range. After confirming that the blasting vibration of the protected object is safe, test the blasting effect after the explosive density division, and do not further reduce the explosive density.

[0048] The method of the present invention realizes effective control of tunnel blasting vibration by filling bulk explosives with adjustable density without changing the tunnel blasting hole network parameters and delay settings and without affecting the construction efficiency. The method is suitable for tunnels with various complex geological conditions, does not affect the construction mood and efficiency of construction workers, and solves the contradiction between traditional tunnel blasting vibration control and construction efficiency.

[0049] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0050] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A tunnel blasting vibration control method based on explosive density zoning, characterized in that: The steps include: (1) Conventional tunnel blasting design and drilling and blasting operations, and blasting vibration monitoring; (2) Using the blasting vibration monitoring results, the tunnel blasting vibration propagation attenuation formula is regressed and fitted, and then the safe allowable explosive dosage for tunnel blasting is inferred; (3) Determine the charge amount for adjusting the borehole based on the conventional unit consumption and the safe allowable charge amount; (4) Keeping the explosive energy and the length of the blasthole charge consistent, calculate the adjusted density of the explosive filled in the blasthole after the charge amount is adjusted; (5) Configure density-adjustable explosives to achieve tunnel blasthole charge density zoning; (6) Check in accordance with steps (1) and (2) that the blasting vibration is within the safe allowable range after the explosive density is divided into zones.

2. The tunnel blasting vibration control method based on explosive density zoning according to claim 1 is characterized in that: Step (1) specifically includes: carrying out conventional tunnel blasting design, determining the explosive consumption range for blasting the tunnel slot holes, auxiliary holes and peripheral holes, and performing drilling and blasting operations according to the conventional design, carrying out blasting vibration monitoring during the conventional blasting process, and arranging no less than 5 blasting vibration monitoring points between the blasting source and the protected object at the tunnel face before blasting, and arranging at least 1 blasting vibration monitoring point at the protected object.

3. The tunnel blasting vibration control method based on explosive density zoning according to claim 1 is characterized in that: Step (2) is specifically: using the blasting vibration monitoring results in the horizontal radial, horizontal tangential and vertical directions to regress and fit the tunnel blasting vibration propagation attenuation formula in the horizontal radial, horizontal tangential and vertical directions: V=K(Q 13 / R)α In the formula, V is the blasting vibration velocity, Q is the single-stage charge, R is the distance from the blasting center, K and α are attenuation constants, where V is determined by the blasting vibration monitoring results, Q is determined according to the blasting design, R is obtained by on-site measurement, and K and α are determined by linear regression fitting; The formula for safe charge dosage allowed for tunnel blasting is obtained from the above formula: [Q]=R([V] / K) 3α , [V] is the blasting vibration safety control standard for the protected object, which is determined by the Blasting Safety Regulations (GB6722); Substitute the distance R between the protected object and the blasting source of the slot holes, auxiliary holes and peripheral holes determined by on-site measurements into the above safe charge formula to obtain the allowable safe charge for blasting the slot holes, auxiliary holes and peripheral holes in the horizontal radial, horizontal tangential and vertical directions. To ensure the safety of the protected object, according to relevant specifications, the allowable safe charge for blasting the slot holes, auxiliary holes and peripheral holes is the minimum value calculated from the blasting vibration propagation attenuation formula in the horizontal radial, horizontal tangential and vertical directions.

4. The tunnel blasting vibration control method based on explosive density zoning according to claim 1 is characterized in that: Step (3) specifically comprises: under the condition that the tunnel blasting hole network parameters and the detonation network obtained in step (1) remain unchanged, in order to reduce the blasting vibration, the lower limit of the explosive unit consumption range q of the tunnel blasting slot hole, auxiliary hole and peripheral hole in step (1) is taken and the value is calculated according to Q 调 =qabH determines the adjusted charge of conventional density explosives for slot holes, auxiliary holes and peripheral holes, where a and b are the distance between blast holes and row spacing, H is the depth of the blast hole, and Q 调 Less than [Q].

5. The tunnel blasting vibration control method based on explosive density zoning according to claim 1 is characterized in that: Step (4) is specifically: based on the principle of consistent explosive energy, the charge length L and volume V of the slot hole, auxiliary hole and peripheral hole are kept unchanged, and the charge amount obtained in step (3) is adjusted according to ρ=kQ 调 / V calculates the adjusted density ρ of density-adjusted explosives loaded in slot holes, auxiliary holes and peripheral holes, where k is the conversion coefficient of the energy of explosives of different densities, which is provided by the explosives manufacturer.

6. The tunnel blasting vibration control method based on explosive density zoning according to claim 1 is characterized in that: Step (5) specifically comprises: according to the calculation result of adjusting the density of explosives filled in the slot holes, auxiliary holes and peripheral holes, the explosives factory configures density-adjustable explosives of corresponding density, and respectively fills the slot holes, auxiliary holes and peripheral holes with density-adjustable explosives of different densities, so as to realize the charging density zoning of the slot holes, auxiliary holes and peripheral holes. In addition to filling the density-adjustable explosives of corresponding density in the charging process, the drilling, charging, filling, networking and detonating operations are completed according to the conventional drilling and blasting operation process. The charging density of each slot hole, auxiliary hole and peripheral hole area can be further refined according to the need of blasting vibration control according to steps (3) and (4) to cyclically refine the explosive density zoning.

7. The tunnel blasting vibration control method based on explosive density zoning according to claim 1 is characterized in that: Step (6) specifically comprises: carrying out tunnel blasting vibration monitoring according to the requirements in steps (1) and (2), verifying that the blasting vibration of the protected object after the explosive density zoning is within the safe allowable range, and after determining that the blasting vibration of the protected object is safe, testing the blasting effect after the explosive density zoning, if the blocks after blasting are relatively uniform and there are no large blocks, indicating that the blasting effect can be well achieved, then further reducing the charge density of the slot holes, auxiliary holes and peripheral holes according to a certain reduction ratio to achieve stricter blasting vibration control, when the block footage rate after blasting exceeds the specification requirements, the reduction ratio is calculated according to 0.8 to 0.9 based on the actual situation on site, wherein the degree of further reduction of the explosive density is determined according to the blasting effect, and if the blasting fragmentation effect just meets the specification requirements, the explosive density is not further reduced.

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