Hard rock stratum blasting excavation method and blasting delay time calculation method

Abstract

The invention relates to the technical field of hard rock stratum blasting construction, and discloses a hard rock stratum blasting excavation method and a blasting delay time calculation method. The technical problems that in the prior art, in underground engineering drilling and blasting method construction, harmful effects exist, vibration generated by blasting is difficult to control, the surrounding environment is affected, the blasting efficiency is low, the construction period is long, and the engineering cost is high are solved. The method comprises the following steps that the tunneling blasting delay time is calculated, and vertical shaft large-diameter empty hole underholing blasting is carried out; vibration reduction holes are formed in the tunnel and the vertical shaft and between the blast hole and the protection object; and tunnel driving blasting charge and vibration effect test are carried out. The technical level of hard rock stratum blasting excavation construction is improved, and fine design and construction of hard rock stratum blasting and control over harmful effects are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of hard rock stratum blasting construction, and in particular to a hard rock stratum blasting excavation method and a blasting delay time calculation method. Background Art

[0002] With the acceleration of urbanization, urban traffic pressure is increasing. As an efficient public transportation mode, the demand for subway construction is constantly increasing. However, the construction of urban subway tunnels faces many challenges, especially the blasting and excavation of super-large cross-section tunnels in complex environments. These challenges mainly include blasting operations in densely populated areas, ensuring construction safety, avoiding damage to the surrounding environment and personnel, and improving construction efficiency, reducing construction cycles, reducing costs, and reducing the impact on the environment during construction, such as noise, dust and vibration, while ensuring safety. The blasting and excavation technology of super-large cross-section tunnels has high requirements and requires precise control of blasting parameters to ensure the quality and stability of the tunnel. Although the existing blasting and excavation technology for hard rock formations can meet construction needs to a certain extent, there are still some limitations.

[0003] The Chinese patent document 201810032412.1 in the prior art discloses a hard rock stratum blasting excavation method applied to the field of tunnel excavation technology, wherein a pre-crack hole group (3) is arranged on a blasting surface (1) near an underground pipeline (2), and a smooth hole group (4) and a groove hole group (5) are also arranged on the blasting surface (1), and explosives are respectively loaded in the pre-crack holes of the pre-crack hole group (3), the smooth holes of the smooth hole group (4), and the groove holes of the groove hole group (5); the pre-crack hole group (3) is detonated first, then the groove hole group (5) is detonated, and finally the smooth hole group (4) is detonated.

[0004] However, during the implementation of the above scheme, there are at least the following technical problems: there are harmful effects in the construction of underground engineering drilling and blasting, it is difficult to control the vibration caused by blasting, which leads to impact on the surrounding environment, and the blasting efficiency is low, the construction period is long, and the engineering cost is high. Therefore, it is urgent to propose a hard rock stratum blasting excavation method and a blasting delay time calculation method. Summary of the invention

[0005] In view of the above technical problems, the present disclosure provides a hard rock formation blasting excavation method and a blasting delay time calculation method, which solves the technical problems of harmful effects in the construction of underground engineering drilling and blasting methods in the prior art, difficulty in controlling the vibration generated by blasting, resulting in impact on the surrounding environment, low blasting efficiency, long construction period, and high engineering cost. The present invention makes full use of modern blasting monitoring technology, numerical analysis, and field tests, implements the concept of green and environmentally friendly construction, and develops hard rock formation blasting excavation devices and methods of use. Through modern blasting monitoring technology and field blasting tests as the main research method, supplemented by numerical simulation, a systematic study of hard rock formation blasting excavation devices and methods of use is carried out, and corresponding harmful effect control technology is proposed. The present invention improves the technical level of hard rock formation blasting excavation construction, and realizes the fine design and careful construction of subway hard rock formation blasting and the control of harmful effects.

[0006] According to one aspect of the present disclosure, a hard rock stratum blasting excavation method is designed, comprising the following steps:

[0007] Step 1: Calculate the delay time of tunnel excavation blasting, and set the number of surrounding holes to be detonated simultaneously according to the delay time. Use digital electronic detonators to delay the time so that the vibration waves of the first blasting hole and the later blasting hole form a reasonable phase difference, so that the superimposed vibration intensity is reduced to a level lower than that of single-hole blasting.

[0008] Step 2: Large diameter hollow hole slot blasting in the vertical shaft; by changing the hollow hole diameter (R) / the distance between the hollow hole and the first blasting hole

[0009] (L) ratio, slot arrangement parameters, and analysis of the relationship and regularity between different slot structures and surrounding rock conditions, cycle footage, rock breaking effect, and peak vibration velocity of blasting in sensitive areas;

[0010] Step three, arranging vibration reduction holes in the tunnel and the shaft, and between the blast holes and the protection objects, so that the explosion stress wave is disturbed when propagating in the rock mass, so as to achieve the vibration reduction effect;

[0011] Step 4: Tunnel excavation blasting charges and test vibration effects. According to the different blasting vibration reduction mechanisms, two types of test schemes are designed: axial uncoupled charges and radial uncoupled charges. The effects of different vibration reduction forms on the peak vibration velocity of the particle are tested respectively.

[0012] In some embodiments of the present disclosure, the step 1 of calculating the tunnel excavation blasting delay time further includes the following steps:

[0013] (1) Numerical simulation: a. Establish numerical models with different delay times; b. Analyze the vibration reduction effect of blasting numerical simulation; c. Establish numerical models with different delay times for peripheral holes; d. Obtain theoretically reasonable delay time and the maximum number of peripheral holes to be detonated simultaneously;

[0014] (2) Field test: a. Field test with different delay times; b. Analysis of blasting rock breaking effect and vibration reduction effect; c.

[0015] On-site test of different delay times for surrounding holes; d. Obtaining reasonable on-site delay time and the maximum number of surrounding holes to be detonated simultaneously;

[0016] (3) The numerical simulation and field test are mutually verified and optimized to obtain the optimal delay time and the number of simultaneous detonations of peripheral holes that are consistent with the actual project.

[0017] In some embodiments of the present disclosure, the large-diameter hollow hole blasting in the vertical shaft in step 2 further includes the following steps:

[0018] (1) Numerical simulation: Establish numerical models of different hollow hole diameters in the shaft, including blastholes and explosives in the slotting area, and construct a three-dimensional numerical model of slotting blasting in proportion to the actual situation. Extract and analyze the vibration reduction effect at fixed monitoring points of different test schemes, blasting peak vibration velocity, rock mass crushing effect in the slotting area, and blasthole utilization rate;

[0019] (2) Field test: blasting of different hollow hole diameters in the test shaft, and comprehensive evaluation of the field test results through the peak velocity of the particle point after blasting, rock breaking effect and fragmentation; keeping the total charge of the slot holes consistent during the test, and dividing the test into multiple test groups according to the ratio of hollow hole diameter / blasthole spacing and slot hole arrangement parameters, and analyzing the vibration reduction effect and rock breaking effect;

[0020] (3) The numerical simulation and field test are mutually verified and optimized to obtain the blasting parameters of the large-diameter hollow hole in the vertical shaft, such as the diameter and depth of the hole.

[0021] In some embodiments of the present disclosure, the step 3 of arranging tunnel and shaft vibration reduction holes further includes the following steps:

[0022] (1) Numerical simulation: establish numerical models with different vibration reduction hole parameters and analyze the effects of vibration reduction hole parameters on blasting vibration reduction; the experimental variables include the number of vibration reduction hole rows, the diameter of the vibration reduction holes, the row spacing, the spacing, and the coverage rate;

[0023] (2) Field test, test different vibration reduction hole parameters, and analyze the vibration reduction effect and blasting spectrum characteristics;

[0024] (3) Mutually verify and optimize the numerical simulation and the field test to obtain vibration reduction hole parameters that match the field. In some embodiments of the present disclosure, the tunnel excavation blasting charging and vibration effect testing in step 4 further includes the following steps:

[0025] (1) Numerical simulation: establish numerical models of different vibration-damping charge structures and analyze the vibration-damping effects of different charge structures; the experimental variables include conventional charge, eccentric charge, and hole bottom spacing;

[0026] (2) Field tests, tests on different vibration-reducing charge structures, and analysis of the vibration-reduction effects and vibration-reduction spectrum characteristics;

[0027] (3) Mutually verify and optimize the numerical simulation and field test to obtain a vibration-damping charge structure that matches the field. In some embodiments of the present disclosure, the tunneling blasting charge includes a water-sealed blasting charge structure and a smooth blasting charge structure;

[0028] The water seal blasting charge structure parameter optimization test comprises the following steps:

[0029] (1) Numerical simulation: a. Model establishment: Establish numerical models of different water-seal blasting charge structures and parameters; b. Test: Water-seal blasting test, test parameters include different medium effects, energy transfer laws, and surrounding rock damage characteristics; c. Result analysis: Analyze the influence of different charge structures and parameters on blasting effect, blasting effect parameters include dust reduction effect and blasting fragmentation effect;

[0030] (2) Field test, analysis of the impact of different charge structures and parameters on blasting effects, including dust reduction effect and blasting fragmentation effect;

[0031] (3) Mutually verify and optimize the numerical simulation and the field test to obtain the vibration reduction hole parameters that match the field. In some embodiments of the present disclosure, the smooth blasting charge structure parameter optimization test includes the following steps:

[0032] (1) Numerical simulation: a. Establish numerical models of different peripheral hole charge structures. The experimental variables in the model include reasonable spacing, conventional charge structure, segmented charge structure, and different segment ratios; b. Analyze the influence of peripheral hole segmentation on smooth blasting effect;

[0033] (2) On-site test: On-site optimization test of peripheral hole charge structure, the optimization parameters include blasting fragmentation distribution and smooth blasting effect;

[0034] (3) The numerical simulation and field test are mutually verified and optimized to obtain the peripheral hole segmented charging parameters that match the site.

[0035] According to another aspect of the present disclosure, a method for calculating the blasting delay time of a hard rock formation is designed, which is applicable to the above-mentioned hard rock formation blasting excavation method and is used to calculate the reasonable delay interval Δt between holes when blasting each hole in the tunnel excavation blasting construction process, including the following steps:

[0036] Long delay: Through the delay, the vibration waves between the first blast hole and the later blast hole are separated in time to avoid the superposition of vibration waves, so that the blasting vibration intensity is equal to the vibration intensity of single-hole blasting;

[0037] Or short delay: through the delay of digital electronic detonator, the vibration waves of the first blast hole and the later blast hole form a reasonable phase difference,

[0038] Thus, the two waves are superimposed and interfere with each other, so that the vibration intensity after superposition is reduced to a level lower than that of single-hole blasting;

[0039] Short delay: When two waves meet at different peaks, assume that the amplitude B and frequency ω of the two waves generated during the blasting are the same, the propagation direction is consistent, but the phase angle is different; assume that the two waves are: y1 = Bsin (ωt-β), y2 = Bsin (ωt-μ); the two waves are superimposed in the same direction after the blasting, that is:

[0040] Y=y1+y2=Bsin(ωt-β)+Bsin(ωt-μ) (1)

[0041] In formula (1), Y is the superposition amplitude; y1 is the amplitude of the previous blast, y2 is the amplitude of the next blast; β is the phase angle of the previous blast, μ is the phase angle of the next blast; t is the time;

[0042] Simplifying formula (1), we can get

[0043]

[0044] From formula (2), we know that the magnitude of the superposition amplitude is determined by the phase angle. When the phase angle meets certain conditions, the two waves have obvious mutual interference, so |Y| < 1, that is, it satisfies:

[0045]

[0046] From formula (3), we can infer that

[0047]

[0048] Let Δt be the time difference between the phase angles of the two waves reaching the monitoring point, that is:

[0049]

[0050] Substituting formula (5) into formula (4) and simplifying it, we get:

[0051]

[0052] The two waves Δt satisfy the above conditions, that is, superposition of phase-shifted interference is achieved to reduce vibration;

[0053] The peak and trough interference is superimposed. When the interval between two waves with opposite phases is a cardinality multiple of the period, the optimal vibration reduction effect is achieved.

[0054] Δt=T(2K+1) / 2 (7). In some embodiments of the present disclosure, the value of n in formula (6) is 1, and the test blast hole delay is between 2T+T / 3 and

[0055] Within the range of 2T+2T / 3.

[0056] The beneficial effects of the present invention are:

[0057] 1. Make full use of modern blasting monitoring technology, numerical analysis and field tests, implement the concept of green and environmentally friendly construction, and propose corresponding precise control technology for harmful effects through modern blasting monitoring technology and field blasting tests as the main research method, supplemented by numerical simulation. This will solve the common problem of difficult-to-control harmful effects in the traditional underground engineering drilling and blasting construction method, improve the technical level of drilling and blasting construction for ultra-large-section subway tunnels in sensitive urban environments, and achieve detailed design and careful construction of subway hard rock blasting and precise control of harmful effects.

[0058] 2. The optimal delay time combination for subway tunnel and shaft blasting under different blasting environments is obtained, which can improve the safety and efficiency of drilling and blasting construction of large-section subway tunnels in sensitive urban environments. Vibration-reducing holes are added between the blastholes and the protected objects, and the wave propagation is disturbed, and the transmitted waves are reduced, thereby achieving a vibration reduction effect, reducing vibration and noise, and protecting the surrounding environment.

[0059] 3. By accurately calculating the delay time of tunnel excavation blasting and reasonably setting the number of simultaneous detonations in the surrounding holes, the vibration waves generated by the blasting can be effectively controlled. The use of digital electronic detonators to achieve precise delays allows the vibration waves between the first blasting hole and the next blasting hole to form staggered peaks in time and phase, thereby reducing the overall vibration intensity.

[0060] 4. The large-diameter hollow hole slot blasting technology in the vertical shaft optimizes the blasting effect under surrounding rock conditions by adjusting the ratio of the hollow hole diameter to the blasthole spacing and the slot hole layout parameters, while reducing the impact on sensitive areas.

[0061] 5. The arrangement of vibration reduction holes further weakens the propagation of explosion stress waves in the rock mass and provides additional vibration reduction effect.

[0062] 6. The design of different types of charge structures helps to improve the quality and efficiency of rock crushing. Eccentric charge and segmented charge structures can better concentrate energy in a predetermined direction and increase the crushing effect.

[0063] 7. The water-seal blasting charge structure not only improves the dust reduction effect, but also improves the blasting and crushing effect, which is conducive to the smooth progress of subsequent construction.

[0064] 8. The smooth blasting charge structure optimizes the formation of the tunnel contour and improves the quality of smooth blasting through reasonable spacing and segmentation ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 A flowchart for calculating the delay time of tunnel excavation blasting;

[0066] Figure 2 This is a flowchart of the large diameter hole blasting process in the vertical shaft;

[0067] Figure 3 A flowchart for arranging vibration reduction holes in tunnels and shafts;

[0068] Figure 4 This is a flow chart of the water-seal blasting charge structure test;

[0069] Figure 5 This is a flow chart of the smooth blasting charge structure test. DETAILED DESCRIPTION

[0070] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0071] Example 1

[0072] This example discloses a hard rock stratum blasting excavation method and a blasting delay time calculation method, see Figures 1 to 5 ;

[0073] A method for blasting excavation of hard rock formations is designed, comprising the following steps:

[0074] Step 1: Calculate the delay time of tunnel excavation blasting, and set the number of surrounding holes to be detonated simultaneously according to the delay time. Use digital electronic detonators to delay the time so that the vibration waves of the first blasting hole and the later blasting hole form a reasonable phase difference, so that the superimposed vibration intensity is reduced to a level lower than that of single-hole blasting.

[0075] Step 2: Large diameter hollow hole slot blasting in the vertical shaft; by changing the hollow hole diameter (R) / the distance between the hollow hole and the first blasting hole

[0076] (L) ratio, slot arrangement parameters, and analysis of the relationship and regularity between different slot structures and surrounding rock conditions, cycle footage, rock breaking effect, and peak vibration velocity of blasting in sensitive areas;

[0077] Step three, arranging vibration reduction holes in the tunnel and the shaft, and between the blast holes and the protection objects, so that the explosion stress wave is disturbed when propagating in the rock mass, so as to achieve the vibration reduction effect;

[0078] Step 4: Tunnel excavation blasting charges and test vibration effects. According to the different blasting vibration reduction mechanisms, two types of test schemes are designed: axial uncoupled charges and radial uncoupled charges. The effects of different vibration reduction forms on the peak vibration velocity of the particle are tested respectively.

[0079] In some embodiments of the present disclosure, the step 1 of calculating the tunnel excavation blasting delay time further includes the following steps:

[0080] (1) Numerical simulation: a. Establish numerical models with different delay times; b. Analyze the vibration reduction effect of blasting numerical simulation; c. Establish numerical models with different delay times for peripheral holes; d. Obtain theoretically reasonable delay time and the maximum number of peripheral holes to be detonated simultaneously;

[0081] (2) Field test: a. Field test with different delay times; b. Analysis of blasting rock breaking effect and vibration reduction effect; c.

[0082] On-site test of different delay times for surrounding holes; d. Obtaining reasonable on-site delay time and the maximum number of surrounding holes to be detonated simultaneously;

[0083] (3) The numerical simulation and field test are mutually verified and optimized to obtain the optimal delay time and the number of simultaneous detonations of peripheral holes that are consistent with the actual project.

[0084] In some embodiments of the present disclosure, the large-diameter hollow hole blasting in the vertical shaft in step 2 further includes the following steps:

[0085] (1) Numerical simulation: Establish numerical models of different hollow hole diameters in the shaft, including blastholes and explosives in the slotting area, and construct a three-dimensional numerical model of slotting blasting in proportion to the actual situation. Extract and analyze the vibration reduction effect at fixed monitoring points of different test schemes, blasting peak vibration velocity, rock mass crushing effect in the slotting area, and blasthole utilization rate;

[0086] (2) Field test: blasting of different hollow hole diameters in the test shaft, and comprehensive evaluation of the field test results through the peak velocity of the particle point after blasting, rock breaking effect and fragmentation; keeping the total charge of the slot holes consistent during the test, and dividing the test into multiple test groups according to the ratio of hollow hole diameter / blasthole spacing and slot hole arrangement parameters, and analyzing the vibration reduction effect and rock breaking effect;

[0087] (3) The numerical simulation and field test are mutually verified and optimized to obtain the blasting parameters of the large-diameter hollow hole in the vertical shaft, such as the diameter and depth of the hole.

[0088] In some embodiments of the present disclosure, the step 3 of arranging tunnel and shaft vibration reduction holes further includes the following steps:

[0089] (1) Numerical simulation: establish numerical models with different vibration reduction hole parameters and analyze the effects of vibration reduction hole parameters on blasting vibration reduction; the experimental variables include the number of vibration reduction hole rows, the diameter of the vibration reduction holes, the row spacing, the spacing, and the coverage rate;

[0090] (2) Field test, test different vibration reduction hole parameters, and analyze the vibration reduction effect and blasting spectrum characteristics;

[0091] (3) The numerical simulation and field test are mutually verified and optimized to obtain the vibration-damping hole parameters that match the site.

[0092] In some embodiments of the present disclosure, the tunnel excavation blasting charging and testing the vibration effect in step 4 further includes the following steps:

[0093] (1) Numerical simulation: establish numerical models of different vibration-damping charge structures and analyze the vibration-damping effects of different charge structures; the experimental variables include conventional charge, eccentric charge, and hole bottom spacing;

[0094] (2) Field tests, tests on different vibration-reducing charge structures, and analysis of the vibration-reduction effects and vibration-reduction spectrum characteristics;

[0095] (3) Mutually verify and optimize the numerical simulation and field test to obtain a vibration-damping charge structure that matches the field. In some embodiments of the present disclosure, the tunneling blasting charge includes a water-sealed blasting charge structure and a smooth blasting charge structure;

[0096] The water seal blasting charge structure parameter optimization test comprises the following steps:

[0097] (1) Numerical simulation: a. Model establishment: Establish numerical models of different water-seal blasting charge structures and parameters; b. Test: Water-seal blasting test, test parameters include different medium effects, energy transfer laws, and surrounding rock damage characteristics; c. Result analysis: Analyze the influence of different charge structures and parameters on blasting effect, blasting effect parameters include dust reduction effect and blasting fragmentation effect;

[0098] (2) Field test, analysis of the impact of different charge structures and parameters on blasting effects, including dust reduction effect and blasting fragmentation effect;

[0099] (3) Mutually verify and optimize the numerical simulation and the field test to obtain the vibration reduction hole parameters that match the field. In some embodiments of the present disclosure, the smooth blasting charge structure parameter optimization test includes the following steps:

[0100] (1) Numerical simulation: a. Establish numerical models of different peripheral hole charge structures. The experimental variables in the model include reasonable spacing, conventional charge structure, segmented charge structure, and different segment ratios; b. Analyze the influence of peripheral hole segmentation on smooth blasting effect;

[0101] (2) On-site test: On-site optimization test of peripheral hole charge structure, the optimization parameters include blasting fragmentation distribution and smooth blasting effect;

[0102] (3) The numerical simulation and field test are mutually verified and optimized to obtain the peripheral hole segmented charging parameters that match the site.

[0103] A method for calculating the delay time of blasting in hard rock formations is applicable to the above-mentioned hard rock formation blasting excavation method, and is used to calculate the reasonable delay interval Δt between holes when blasting each hole in the tunnel excavation blasting construction process, comprising the following steps:

[0104] Long delay: Through the delay, the vibration waves between the first blast hole and the later blast hole are separated in time to avoid the superposition of vibration waves, so that the blasting vibration intensity is equal to the vibration intensity of single-hole blasting;

[0105] Or short delay: through the delay of digital electronic detonator, the vibration waves of the first blast hole and the later blast hole form a reasonable phase difference,

[0106] Thus, the two waves are superimposed and interfere with each other, so that the vibration intensity after superposition is reduced to a level lower than that of single-hole blasting;

[0107] Short delay: When two waves meet at different peaks, assume that the amplitude B and frequency ω of the two waves generated during the blasting are the same, the propagation direction is consistent, but the phase angle is different; assume that the two waves are: y1 = Bsin (ωt-β), y2 = Bsin (ωt-μ); the two waves are superimposed in the same direction after the blasting, that is:

[0108] Y=y1+y2=Bsin(ωt-β)+Bsin(ωt-μ) (1)

[0109] In formula (1), Y is the superposition amplitude; y1 is the amplitude of the previous blast, y2 is the amplitude of the next blast; β is the phase angle of the previous blast, μ is the phase angle of the next blast; t is the time;

[0110] Simplifying formula (1), we can get

[0111]

[0112] From formula (2), we know that the magnitude of the superposition amplitude is determined by the phase angle. When the phase angle meets certain conditions, the two waves have obvious mutual interference, so |Y| < 1, that is, it satisfies:

[0113]

[0114] From formula (3), we can infer that

[0115]

[0116] Let Δt be the time difference between the phase angles of the two waves reaching the monitoring point, that is:

[0117]

[0118] Substituting formula (5) into formula (4) and simplifying it, we get:

[0119]

[0120] The two waves Δt satisfy the above conditions, that is, superposition of phase-shifted interference is achieved to reduce vibration;

[0121] The peak and trough interference is superimposed. When the interval between two waves with opposite phases is a cardinality multiple of the period, the optimal vibration reduction effect is achieved.

[0122] Δt=T(2K+1) / 2 (7).

[0123] The blasting interference vibration reduction test was carried out using the electronic detonator detonation network. When the delay time of the electronic detonator meets Δt, the waveform superposition interferes with each other, and finally the blasting vibration is reduced under the same conditions. The delay time range of the electronic detonator is calculated according to formulas (6) to (7). In order to eliminate the vibration in the main vibration area that affects the vibration effect in the actual blasting construction, the waveform superposition effect is concentrated in the 1-2 amplitude in the main vibration area. At the same time, considering that the delay time should be greater than the blasting vibration cycle time, the main shock segments of the front and rear seismic waves are separated as much as possible, so as to reduce the delayed blasting vibration to the peak value of the single-hole blasting. However, if the delay time is too long, it is not conducive to the blasting fragmentation effect. Therefore, the value of n in formula (6) is 1. Based on this, the delay range of the test blasthole should be in the range of 2T+T / 3 to 2T+2T / 3.

[0124] Although some preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0125] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of this application and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A hard rock stratum blasting excavation method, characterized in that: The steps include: Step 1: Calculate the delay time of tunnel excavation blasting; and set the number of surrounding holes to be detonated simultaneously according to the delay time, so that the vibration waves of the first blasting hole and the later blasting hole form a reasonable phase difference through the delay of digital electronic detonators, so that the superimposed vibration intensity is reduced to a level lower than that of single-hole blasting; Step 2: Large diameter hollow hole slot blasting in the vertical shaft; by changing the ratio of the hollow hole diameter (R) / the distance between the hollow hole and the first blasting hole (L), and the slot hole arrangement parameters, the relationship and regularity between different slotting structures and surrounding rock conditions, cycle footage, rock breaking effect, and blasting peak vibration velocity in sensitive areas are analyzed; Step three, arranging vibration reduction holes in the tunnel and the shaft, and between the blast holes and the protection objects, so that the explosion stress wave is disturbed when propagating in the rock mass, so as to achieve the vibration reduction effect; Step 4: Tunnel excavation blasting charges and test vibration effects; according to the different blasting vibration reduction mechanisms, two types of test schemes are designed: axial uncoupled charges and radial uncoupled charges, to test the effects of different vibration reduction forms on the peak vibration velocity of the particle.

2. A hard rock stratum blasting excavation method as claimed in claim 1, characterized in that: The step 1 of calculating the tunnel excavation blasting delay time also includes the following steps: (1) Numerical simulation: a. Establish numerical models with different delay times; b. Analyze the vibration reduction effect of blasting numerical simulation; c. Establish numerical models with different delay times for peripheral holes; d. Obtain theoretically reasonable delay time and the maximum number of peripheral holes to be detonated simultaneously; (2) Field test: a. Field test with different delay times; b. Analysis of blasting rock breaking effect and vibration reduction effect; c. Field test of different delay times for surrounding holes; d. Obtaining the reasonable delay time and the maximum number of simultaneous detonation of surrounding holes on site; (3) The numerical simulation and field test are mutually verified and optimized to obtain the optimal delay time and the number of simultaneous detonations of peripheral holes that are consistent with the actual project.

3. A hard rock stratum blasting excavation method as claimed in claim 1, characterized in that: The large-diameter hollow hole blasting in the vertical shaft in step 2 also includes the following steps: (1) Numerical simulation: Establish numerical models of different hollow hole diameters in the shaft, including blastholes and explosives in the slotting area, and construct a three-dimensional numerical model of slotting blasting in proportion to the actual situation. Extract and analyze the vibration reduction effect at fixed monitoring points of different test schemes, blasting peak vibration velocity, rock mass crushing effect in the slotting area, and blasthole utilization rate; (2) Field test: blasting of different hollow hole diameters in the test shaft, and comprehensive evaluation of the field test results through the peak velocity of the particle point after blasting, rock breaking effect and fragmentation; keeping the total charge of the slot holes consistent during the test, and dividing the test into multiple test groups according to the ratio of hollow hole diameter / blasthole spacing and slot hole arrangement parameters, and analyzing the vibration reduction effect and rock breaking effect; (3) The numerical simulation and field test are mutually verified and optimized to obtain the blasting parameters of the large-diameter hollow hole in the vertical shaft, such as the diameter and depth of the hole.

4. A hard rock stratum blasting excavation method as claimed in claim 1, characterized in that: Arranging the tunnel and shaft vibration reduction holes in step 3 also includes the following steps: (1) Numerical simulation: establish numerical models with different vibration reduction hole parameters and analyze the effects of vibration reduction hole parameters on blasting vibration reduction; the experimental variables include the number of vibration reduction hole rows, the diameter of the vibration reduction holes, the row spacing, the spacing, and the coverage rate; (2) Field test, test different vibration reduction hole parameters, and analyze the vibration reduction effect and blasting spectrum characteristics; (3) The numerical simulation and field test are mutually verified and optimized to obtain the vibration-damping hole parameters that match the site.

5. A hard rock stratum blasting excavation method as claimed in claim 1, characterized in that: The tunnel excavation blasting charging and testing the vibration effect in step 4 also includes the following steps: (1) Numerical simulation: establish numerical models of different vibration-damping charge structures and analyze the vibration-damping effects of different charge structures; the experimental variables include conventional charge, eccentric charge, and hole bottom spacing; (2) Field tests, tests on different vibration-reducing charge structures, and analysis of the vibration-reduction effects and vibration-reduction spectrum characteristics; (3) The numerical simulation and field test are mutually verified and optimized to obtain a vibration-damping charge structure that matches the site.

6. A hard rock stratum blasting excavation method as claimed in claim 1, characterized in that: The tunnel excavation blasting charge includes a water-sealed blasting charge structure and a smooth blasting charge structure; The water seal blasting charge structure parameter optimization test comprises the following steps: (1) Numerical simulation: a. Model establishment: Establish numerical models of different water-seal blasting charge structures and parameters; b. Test: Water-seal blasting test, test parameters include different medium effects, energy transfer laws, and surrounding rock damage characteristics; c. Result analysis: Analyze the influence of different charge structures and parameters on blasting effect, blasting effect parameters include dust reduction effect and blasting fragmentation effect; (2) Field test, analysis of the impact of different charge structures and parameters on blasting effects, including dust reduction effect and blasting fragmentation effect; (3) The numerical simulation and field test are mutually verified and optimized to obtain the vibration-damping hole parameters that match the site.

7. A hard rock stratum blasting excavation method as claimed in claim 6, characterized in that: The smooth blasting charge structure parameter optimization test comprises the following steps: (1) Numerical simulation: a. Establish numerical models of different peripheral hole charge structures. The experimental variables in the model include reasonable spacing, conventional charge structure, segmented charge structure, and different segment ratios; b. Analyze the influence of peripheral hole segmentation on smooth blasting effect; (2) On-site test: On-site optimization test of peripheral hole charge structure, the optimization parameters include blasting fragmentation distribution and smooth blasting effect; (3) The numerical simulation and field test are mutually verified and optimized to obtain the peripheral hole segmented charging parameters that match the site.

8. A method for calculating the delay time of blasting in hard rock formations, applicable to the method for blasting excavation in hard rock formations as claimed in claim 1, used to calculate the reasonable delay interval Δt between holes when blasting each hole in a tunnel excavation blasting construction process, characterized in that: The steps include: Long delay: Through the delay, the vibration waves between the first blast hole and the later blast hole are separated in time to avoid the superposition of vibration waves, so that the blasting vibration intensity is equal to the vibration intensity of single-hole blasting; Or short delay: through the delay of digital electronic detonators, the vibration waves of the first blast hole and the second blast hole form a reasonable phase difference, so that the two waves are superimposed and interfere with each other, so that the vibration intensity after superposition is reduced to a level lower than that of single-hole blasting; Short delay: When two waves meet at different peaks, assume that the amplitude B and frequency ω of the two waves generated during the blasting are the same, the propagation direction is consistent, but the phase angle is different; assume that the two waves are: y1 = Bsin (ωt-β), y2 = Bsin (ωt-μ); the two waves are superimposed in the same direction after the blasting, that is: Y=y1+y2=Bsin(ωt-β)+Bsin(ωt-μ) (1) In formula (1), Y is the superposition amplitude; y1 is the amplitude of the previous blast, y2 is the amplitude of the next blast; β is the phase angle of the previous blast, μ is the phase angle of the next blast; t is the time; Simplifying formula (1), we can get From formula (2), we know that the magnitude of the superposition amplitude is determined by the phase angle. When the phase angle meets certain conditions, the two waves have obvious mutual interference, so |Y| < 1, that is, it satisfies: From formula (3), we can infer that Let Δt be the time difference between the phase angles of the two waves reaching the monitoring point, that is: Substituting formula (5) into formula (4) and simplifying it, we get: The two waves Δt satisfy the above conditions, that is, superposition of phase-shifted interference is achieved to reduce vibration; The peak and trough interference is superimposed. When the interval between two waves with opposite phases is a cardinality multiple of the period, the optimal vibration reduction effect is achieved. Δt=T(2K+1) / 2 (7).

9. The method for calculating the blasting delay time in hard rock formations according to claim 8, characterized in that: n in formula (6) The value is 1, and the test blast hole delay is in the range of 2T+T / 3 to 2T+2T / 3.

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