Method and system for determining millisecond time in frozen rock millisecond blasting

Abstract

The application provides a method and system for determining millisecond millisecond differential blasting time of frozen rock, which can reasonably determine the millisecond differential blasting time of frozen rock in cold regions and accurately predict the blasting effect. The method comprises the following steps: step 1, considering the influence of temperature on wave velocity, calculating the stress wave propagation velocity of frozen rock, wherein T represents the temperature of rock; A, B, C and D are parameters related to the longitudinal wave velocity of rock, which are obtained by fitting the wave velocity data of rock at different temperatures; step 2, calculating the frozen rock blasting millisecond differential time based on the stress wave propagation velocity. The system comprises: a wave velocity acquisition unit, which considers the influence of temperature on wave velocity and adopts the stress wave propagation velocity of frozen rock; a blasting millisecond differential time calculation unit, which calculates the frozen rock blasting millisecond differential time based on the stress wave propagation velocity; an input display unit, which inputs the operation instruction of the operator and displays the corresponding information according to the operation instruction; and a control unit, which is in communication with each unit and controls the operation of each unit.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of frozen rock blasting, and particularly relates to a method and system for determining millisecond delay time in frozen rock millisecond delay blasting. BACKGROUND

[0002] Millisecond delay blasting refers to a blasting method in which adjacent explosive charges are sequentially initiated with millisecond time intervals in a pre-designed order. Millisecond delay blasting has the characteristics of large blasting volume, good crushing quality, and high blasting efficiency.

[0003] Reasonable open-air millisecond delay blasting delay time can improve blasting quality, reduce explosive unit consumption, increase rock crushing rate, reduce blasting vibration, and improve economic benefits. Millisecond delay blasting divides the blast holes into groups and sequentially initiates them with millisecond time intervals, so that the blasting seismic wave energy is dispersed in time and space, thereby reducing the blasting seismic intensity. From the perspective of shock reduction, a longer millisecond delay time is needed to completely separate the blasting seismic waves on the time axis. However, in order to achieve good crushing effect, the millisecond delay time cannot be too long. Because if the millisecond delay time is too long, the blasting stress field of the first blast hole has already disappeared when the second blast hole is initiated, which reduces the blasting stress superposition effect. At the same time, the blasted rock blocks of the first blast hole have already fallen to the ground, and the crushed rock blocks of the second blast hole have just started to move, which loses the supplementary crushing effect of the blasted rock blocks colliding with each other, affecting the blasting effect. Therefore, when controlling the blasting seismic intensity, both the blasting seismic effect and the crushing effect need to be considered.

[0004] With the gradual development of high-cold regions, large-scale water conservancy projects in these regions almost all face the problem of blasting excavation of frozen rock in high-cold regions. However, the existing various millisecond delay time calculation formulas do not consider the freezing temperature, and the results obtained by using these formulas to calculate and design millisecond delay blasting often differ greatly from the actual situation, and there is an urgent need for a method for reasonably determining the millisecond delay time of millisecond delay blasting in frozen rock areas. SUMMARY

[0005] The present application is made to solve the above problems, and aims to provide a method and system for determining millisecond delay time in frozen rock millisecond delay blasting, which can reasonably determine the millisecond delay time of millisecond delay blasting excavation of frozen rock in cold regions, thereby accurately predicting the blasting effect.

[0006] To achieve the above-mentioned purpose, the present application adopts the following scheme:

[0007] <Method>

[0008] The present application provides a method for determining millisecond delay time in frozen rock millisecond delay blasting, characterized in that it comprises the following steps:

[0009] Step 1: Considering the influence of temperature on wave speed, the stress wave propagation speed C of frozen rock is calculated by using the following formula 1 p(m / s);

[0010]

[0011] In the formula, T represents the temperature of the rock, in ℃, which represents the temperature of the frozen rock when calculating the wave velocity of the frozen rock, and represents the temperature of the rock of the same type as the frozen rock when the data is fitted; A, B, C, and D are parameters related to the wave velocity of the rock, which are obtained by fitting the wave velocity data of the rock at different temperatures;

[0012] Step 2, calculating the millisecond delay time of the frozen rock blasting based on the wave propagation velocity of the stress.

[0013] Preferably, in the method for determining the millisecond delay time in the millisecond delay blasting of the frozen rock provided by the present application, in step 1, the wave velocity data of the rock at different temperatures at least contains data at four different temperatures, and the temperature intervals should be as uniform as possible, for example, 5°, 0°, -5°, -10°, and -15° can be selected.

[0014] Preferably, in the method for determining the millisecond delay time in the millisecond delay blasting of the frozen rock provided by the present application, in step 1, the temperature of the wave velocity data of the rock at different temperatures is selected in the range of 20℃ to -180℃.

[0015] Preferably, in the method for determining the millisecond delay time in the millisecond delay blasting of the frozen rock provided by the present application, in step 1, the wave velocity data of the rock at different temperatures is historical data or experimental data obtained by querying the data.

[0016] Preferably, in the method for determining the millisecond delay time in the millisecond delay blasting of the frozen rock provided by the present application, in step 1, when the values of A, B, C, and D cannot be obtained through historical data, a rock wave velocity test is designed, and a group of (T i , C pi ) is obtained through the test at each temperature, and then the following formula 2 is constructed:

[0017]

[0018] When S takes the minimum value, the corresponding values of A, B, C, and D are the parameter values.

[0019] Preferably, in the method for determining the millisecond delay time in the millisecond delay blasting of the frozen rock provided by the present application, in step 1, when the rock is granite, the values of A, B, C, and D are recommended to be A=8331.94, B=111.07, C=150.57, and D=0.45; and when the rock is andesite, the values of A, B, C, and D are recommended to be A=5195.15, B=30.16, C=104.02, and D=0.86.

[0020] Preferably, the method for determining millisecond time in frozen rock millisecond millisecond blasting provided by the present application, in step 2, the frozen rock blasting millisecond time Δt (s) is calculated by the following formula:

[0021]

[0022] In the formula, α represents the hole spacing, m; W represents the average resistance line of the front row hole, m.

[0023] Preferably, the method for determining millisecond time in frozen rock millisecond millisecond blasting provided by the present application, in step 2, the frozen rock blasting millisecond time Δt is calculated by the following formula:

[0024]

[0025] In the formula, α represents the hole spacing, m; Q represents the charge mass, kg.

[0026] Preferably, the method for determining millisecond time in frozen rock millisecond millisecond blasting provided by the present application, in step 2, the frozen rock blasting millisecond time Δt is calculated by the following formula:

[0027]

[0028] In the formula, Q represents the charge mass, kg; r e , r r Respectively, the density of explosive and rock, kg / m 3 ; D e Represents the detonation velocity of explosive, m / s; c r Represents the stress wave propagation velocity in rock, m / s; v represents the average speed of rock movement, m / s; S represents the crack width behind the hole, mm; b is 1-2, which is determined according to the test data.

[0029] <system>

[0030] Further, the present application also provides a system for determining millisecond time in frozen rock millisecond millisecond blasting, which can automatically realize the above <method>, comprising:

[0031] Wave velocity acquisition unit, considering the influence of temperature on wave velocity, the stress wave propagation velocity C p of frozen rock is calculated by the following formula 1:

[0032]

[0033] In the formula, T represents the temperature of rock; A, B, C, D are parameters related to the longitudinal wave velocity of rock, which are obtained by fitting the wave velocity data of rock at different temperatures;

[0034] Blasting millisecond time calculation unit, which calculates the frozen rock blasting millisecond time based on the stress wave propagation velocity;

[0035] The input display part is used for inputting operation instruction of the operator and displaying corresponding information according to the operation instruction;

[0036] The control part is connected with the wave velocity acquisition part, the blasting millisecond time calculation part and the input display part, and controls the operation of them.

[0037] Preferably, the system for determining millisecond time in frozen rock millisecond blasting provided by the present application, in the wave velocity acquisition part, the rock wave velocity data at different temperatures at least contains data at four different temperatures, and the interval between different temperatures should be as uniform as possible.

[0038] Preferably, the system for determining millisecond time in frozen rock millisecond blasting provided by the present application, in the wave velocity acquisition part, the temperature range of the rock wave velocity data at different temperatures is 20℃ to -180℃.

[0039] Preferably, the system for determining millisecond time in frozen rock millisecond blasting provided by the present application, in the wave velocity acquisition part, the rock wave velocity data at different temperatures is historical data or experimental data obtained by inquiry.

[0040] Preferably, the system for determining millisecond time in frozen rock millisecond blasting provided by the present application, in the wave velocity acquisition part, when the A, B, C and D values cannot be obtained through historical data, rock wave velocity test is designed, and a group of (T i , C pi ) is obtained through test at each temperature, i is an integer not less than 4, and then the following formula 2 is constructed:

[0041]

[0042] When S takes the minimum value, the corresponding A, B, C and D values are the parameter values.

[0043] Preferably, the system for determining millisecond time in frozen rock millisecond blasting provided by the present application, in the wave velocity acquisition part, when the rock is granite, the recommended values are A=8331.94, B=111.07, C=150.57 and D=0.45; when the rock is andesite, the recommended values are A=5195.15, B=30.16, C=104.02 and D=0.86.

[0044] Preferably, the system for determining millisecond time in frozen rock millisecond blasting provided by the present application, in the blasting millisecond time calculation part, the frozen rock blasting millisecond time Δt is calculated by using the following formula 3:

[0045]

[0046] In the formula, α represents the hole spacing, and W represents the average burden of the front row hole.

[0047] Preferably, the system for determining millisecond delay time in frozen rock millisecond delay blasting provided by the present application calculates the frozen rock blasting delay time Δt in the blasting delay time calculation unit by using the following formula 5:

[0048]

[0049] In the formula, α represents the hole spacing, and Q represents the charge mass.

[0050] Preferably, the system for determining millisecond delay time in frozen rock millisecond delay blasting provided by the present application calculates the frozen rock blasting delay time Δt in the blasting delay time calculation unit by using the following formula 4:

[0051]

[0052] In the formula, Q represents the charge mass; r e , r r respectively represent the density of explosive and rock; D e represents the detonation velocity of explosive; c r represents the stress wave propagation velocity in rock; v represents the average moving velocity of rock; S represents the crack width behind the hole; and b is 1-2, which is determined according to test data.

[0053] Effects of the application

[0054] The method and system for determining millisecond delay time in frozen rock millisecond delay blasting provided by the present application propose a stress wave propagation velocity considering the temperature influence, and further construct a new millisecond delay blasting delay time calculation method applicable to frozen rock millisecond delay blasting in cold regions. The calculated frozen rock blasting delay time is accurate and consistent with the actual situation. Using the calculation results for blasting prediction can obtain reliable prediction results. For the case of protective blasting excavation, the value calculated by using the present application can better crush the near-zone rock and reduce the impact on the far-zone structure.

[0055] And, the formula parameter of the application can be fitted according to historical data, when the historical data cannot fit the parameter value, the required data can also be fitted according to the design of rock wave velocity test, and the rock wave velocity test can be carried out above 0 DEG C, for example, 0 DEG C to 20 DEG C, at least four temperatures are uniformly selected for test, and the stress wave propagation velocity of negative temperature rock and the blasting delay time of frozen rock can be calculated; When the test environment is more suitable for tests below 0 DEG C, test data below 0 DEG C can also be used; Further, when a certain amount of A, B, C and D parameter values of various rocks are accumulated, the delay time during blasting excavation can be calculated according to the temperature of rock mass during blasting excavation and the type of rock, without further rock test at different temperatures. The test conditions and environment requirements are low, the corresponding data can be conveniently obtained according to the environmental conditions, the data acquisition and calculation process is simple, and the accuracy and convenience are combined. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 The flow chart of the method for determining the millisecond delay time in the frozen rock millisecond millisecond blasting related to the embodiments of the application is shown.

[0057] Figure 2 The formula 2 model solving example related to the embodiments of the application is shown.

[0058] Figure 3 The change rate of the millisecond time from 15 DEG C to -45 DEG C related to the embodiments of the application is shown, wherein (a) is the millisecond change rate, and (b) is the millisecond time.

[0059] Figure 4 The particle vibration velocity spectrum corresponding to different frequencies of the blasting vibration wave related to the embodiments of the application is shown.

[0060] Figure 5 The Figure 4 Enlarged view of the frequency 0-700 region. DETAILED DESCRIPTION

[0061] The specific implementation of the method and system for determining the millisecond delay time in the frozen rock millisecond millisecond blasting related to the application will be described in detail in combination with the drawings.

[0062] <Embodiment one>

[0063] As shown in the formula 1, the method for determining the millisecond delay time in the frozen rock millisecond millisecond blasting related to the embodiments of the application comprises the following steps: Figure 1

[0064] Step 1, considering the influence of temperature on wave velocity, the stress wave propagation velocity C of frozen rock is calculated by using the following formula 1 p ;

[0065] ​

[0066] In the formula, T represents the temperature of frozen rock, in °C; A, B, C, and D are parameters related to the longitudinal wave velocity of the rock, which are obtained by fitting rock wave velocity data at different temperatures.

[0067] The rock wave velocity data at different temperatures are historical data obtained from research or experimental data. In this embodiment, since the values ​​of A, B, C, and D cannot be obtained from historical data, a rock wave velocity experiment is designed to obtain a set of values ​​(T) at each temperature. i C pi ), (T i C pi Let ) represent the i-th set of temperature and stress wave propagation velocity data, where i is an integer not less than 4. Then, construct the following model (Formula 2):

[0068]

[0069] When S reaches its minimum value, the corresponding values ​​of A, B, C, and D are the desired parameter values. Table 1 below shows the wave velocity-related parameters for granite and andesite obtained through fitting in this embodiment. Relevant parameters for other rock types can be obtained by fitting using this method after wave velocity experiments.

[0070] Table 1 Wave velocity-related parameters for different rocks

[0071] A B C D Granite 8331.94 111.07 150.57 0.45 Andesite 5195.15 30.16 104.02 0.86

[0072] Step 2: Calculate the micro-delay time for frozen rock blasting based on the stress wave propagation velocity.

[0073] Obtain the current frozen rock temperature and parameters such as the hole spacing and resistance line of the blasting design. Substitute the parameters obtained in step 1 or the stress wave propagation speed into formula 3 to obtain the micro-delay time during frozen rock blasting.

[0074] The micro-delay time Δt for frozen rock blasting is calculated using the following formula: 3, 4, or 5:

[0075]

[0076]

[0077]

[0078] In the formula, α represents the borehole spacing (m); W represents the average resistance line of the front row of boreholes (m); Q represents the charge mass (kg); and r e r r Densities of explosives and rocks, respectively, in kg / m³ 3 ;D e The detonation velocity of the explosive is expressed in m / s; c rV represents the stress wave propagation speed in the rock, m / s; v represents the moving average speed of the rock, m / s; S represents the slot width at the rear of the hole, mm, generally 10 mm; b is 1-2, determined according to test data.

[0079] The following takes the blasting excavation of a frozen rock slope in a project as an example to calculate the millisecond time during blasting. The frozen rock temperature during blasting in the project is-23 DEG C, the frozen rock is granite, and the initial blasting design parameters are hole spacing alpha = 2 m and standoff distance W = 3 m. The wave speed under different negative temperatures is shown in Table 2. After establishing the model (formula 2) according to the data in Table 2, the parameters A = 8331.94, B = 111.07, C = 150.57 and D = 0.45 related to the wave speed are obtained by using programming to solve, and the fitting results after solving are shown in Figure 2 . Finally, the millisecond time is calculated by using formula 3:

[0080] Table 2 Wave speed test results of rock longitudinal wave in a project

[0081] Serial number Temperature (°C) Longitudinal wave velocity (m / s) 1 15 3801.28 2 0 4040.30 3 -40 4348.88 4 -80 4512.75 5 -120 4857.30 6 -160 5060.35

[0082] Figure 3 The change rate of the millisecond time from 15 DEG C to-40 DEG C is given. It can be seen from Figure 3 that the millisecond time calculated by using the scheme gradually increases as the temperature gradually decreases. When the temperature decreases from 15 DEG C to-40 DEG C, the millisecond time changes by 11%. In the calculation of the millisecond blasting time, the temperature variable is introduced, which can reflect the influence of negative temperature on the properties of rock materials.

[0083] Further, the blasting near-zone vibration monitoring data obtained from the blasting test in Jinghe are analyzed. When the frozen rock temperature is 10 DEG C, -10 DEG C and-30 DEG C, the calculated millisecond time is 2.5 ms, 2.4 ms and 2.3 ms respectively. The particle vibration velocity in the near zone of the explosion source under the millisecond time is subjected to Fourier transform to obtain the velocity spectrum corresponding to different frequencies, which are shown in Figure 4 and Figure 5 . It can be seen that after the vibration frequency is 50 Hz, the high frequency part migrates to the low frequency part, that is, the energy concentrates on the low frequency part, which can make the damage effect of the rock mass in the near zone of blasting more remarkable, and the influence on the far zone is reduced. For the case of protective blasting excavation, the rock mass in the near zone can be better broken by using the calculation results of the present application, and the influence on the far zone structure is reduced.

[0084] When the A, B, C and D parameter values of various types of rocks are accumulated, the temperature of the rock mass during blasting excavation and the type of rock can be directly brought into formulas 3-5 to calculate the delay time during blasting excavation, without having to do rock tests under different temperatures.

[0085] <Embodiment Two>

[0086] The second embodiment provides a system for determining the millisecond delay time in the millisecond differential blasting of frozen rock based on the method of the present application, which comprises a wave velocity acquisition unit, a blasting millisecond delay time calculation unit, an input display unit and a control unit.

[0087] The wave velocity acquisition unit can perform the content described in step 1 above, and the stress wave propagation velocity C of the frozen rock is calculated by formula 1 considering the influence of temperature on the wave velocity. p .

[0088] The blasting millisecond delay time calculation unit can perform the content described in step 2 above, and the blasting millisecond delay time of the frozen rock is calculated by any one of formulas 3-5 based on the stress wave propagation velocity and the parameter acquisition condition.

[0089] The input display unit can allow the operator to input operation instructions and display corresponding information according to the operation instructions. Specifically, the input display unit can display the input, output data and processing process of the wave velocity acquisition unit and the blasting millisecond delay time calculation unit in the form of text, data table or image according to the operation instructions.

[0090] The control unit is in communication with the wave velocity acquisition unit, the blasting millisecond delay time calculation unit and the input display unit, and controls the operation of them.

[0091] The above embodiment is only an example of the technical solution of the present application. The method and system for determining the millisecond delay time in the millisecond differential blasting of frozen rock involved in the present application are not limited to the content described in the above embodiment, but are subject to the scope defined in the claims. Any modification, supplement or equivalent replacement made by the skilled in the art on the basis of the embodiment is within the scope claimed by the claims of the present application.

Claims

1. A method for determining millisecond time in frozen rock millisecond blasting, characterized in that, The method comprises the following steps: Step 1, the stress wave propagation velocity of frozen rock is calculated by using the following formula 1 considering the effect of temperature on wave velocity ; (Formula 1) wherein represents the temperature of the rock; A, B, C, D is a parameter related to the P-wave velocity of the rock, obtained by fitting the rock wave velocity data at different temperatures; rock represents the frozen rock or a rock of the same type as the frozen rock; Step 2, calculating the frozen rock blasting millisecond time based on the stress wave propagation speed; wherein, in step 1, the rock wave velocity data at different temperatures means that a set of rock wave velocity data at each temperature is obtained by historical data or test , ), i is an integer not less than 4.

2. The method for determining millisecond time in frozen rock millisecond blasting according to claim 1, characterized in that: wherein In step 1, the rock wave speed data at different temperatures should contain at least four different temperature data, and the interval between different temperatures should be as uniform as possible.

3. The method for determining millisecond time in frozen rock millisecond blasting according to claim 1, characterized in that: wherein, In step 1, the temperature range of rock wave speed data at different temperatures is 20℃-180℃.

4. The method for determining millisecond time in frozen rock millisecond blasting according to claim 1, characterized in that: wherein In step 1, the rock wave speed data at different temperatures is historical data or experimental data obtained by querying data.

5. The method for determining millisecond time in frozen rock millisecond blasting according to claim 1, characterized in that: wherein In step 1, when the value of the rock wave velocity cannot be obtained through historical data A, B, C, D , a rock wave velocity test is designed, and a set of values is obtained through the test at each temperature , ), i is an integer not less than 4, and then the following formula 2 is constructed: (Formula 2) When S The minimum value is taken, and the corresponding A, B, C, D value is the parameter value sought.

6. The method of determining millisecond time in a frozen rock millisecond blast according to claim 1, characterized in that: wherein, in step 1, when the rock is granite, the values are suggested to be: A = 8331.94 、B = 111.07 、C = 150.57 、D = 0.45; When the rock is andesite, the values are suggested to be: A = 5195.15 、B = 30.16 、C = 104.02 、D = 0.

86.

7. The method for determining millisecond time in frozen rock millisecond blasting according to claim 1, characterized in that: wherein In step 2, the frozen rock blasting millisecond time is calculated using Equation 3 as follows : (Formula 3) wherein represents the hole spacing, represents the average line of resistance of the front row of holes.

8. The method for determining millisecond time in frozen rock millisecond blasting according to claim 1, characterized in that: wherein In step 2, the rock freezing blasting millisecond time is calculated using equation 4 as follows : (Formula 4) wherein denotes the hole spacing, Q denotes the charge mass.

9. The method for determining millisecond time in frozen rock millisecond blasting according to claim 1, characterized in that: wherein, In step 2, the frozen rock blasting millisecond time is calculated using the following equation 5 : (Formula 5) wherein, Q denotes the charge mass; denotes the explosive and rock density, respectively; denotes the explosive detonation velocity; denotes the stress wave propagation velocity in the rock; denotes the rock moving average velocity; denotes the crack slot width behind the hole; is 1-2, determined according to test data.

10. A system for determining millisecond time in frozen rock millisecond blasting, characterized by including: The wave velocity acquisition unit, considering the influence of temperature on wave velocity, calculates the stress wave propagation velocity of frozen rock by using the following formula 1 ; (Formula 1) wherein represents the temperature of the rock; A, B, C, D is a parameter related to the P-wave velocity of the rock, obtained by fitting the rock wave velocity data at different temperatures; rock represents the frozen rock or a rock of the same type as the frozen rock; The blasting millisecond time calculation unit calculates the frozen rock blasting millisecond time based on the stress wave propagation speed; The input display unit inputs the operation command and displays the corresponding information according to the operation command; The control unit is in communication with the wave speed acquisition unit, the blasting millisecond time calculation unit and the input display unit, and controls the operation of them. In the wave velocity acquisition unit, the rock wave velocity data at different temperatures means that a set of rock wave velocity data at each temperature is acquired through historical data or experiments , ), i is an integer not less than 4.

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