A method for calculating and analyzing rock blasting fracture zone radius probability

Abstract

The application discloses a kind of rock blasting fracture zone radius probability calculation analysis methods, it is related to rock mass engineering technical field, the present application includes in rock mass flat surface vertical drilling three test blast holes;Single-hole and cross-hole acoustic detection method is used, and the longitudinal wave velocity of rock mass is obtained;The radius of three test blast holes is measured and counted;Obtain explosive density and explosive detonation speed;The average value and standard deviation of the longitudinal wave velocity of rock mass, the radius of three test blast holes, explosive density, explosive detonation speed are respectively counted, and according to the distribution type of respective average value and standard deviation, generate N random samples;N random samples are substituted into blasting fracture zone radius theoretical formula, and N blasting fracture zone radius is calculated;The exceeding probability that N blasting fracture zone radius is greater than set blasting fracture zone radius is counted;Change set blasting fracture zone radius, and count exceeding probability again;The change curve of exceeding probability with set blasting fracture zone radius is drawn, and rock blasting fracture zone radius is determined.

Description

Technical Field

[0001] This invention relates to the field of rock mass engineering technology, specifically to a method for probabilistic calculation and analysis of the radius of rock burst fracture zone. Background Technology

[0002] In recent years, borehole blasting has been widely used in the construction of sand and gravel mines, water conservancy and hydropower projects, transportation infrastructure, and municipal engineering. Borehole blasting typically involves the release of a large amount of energy; some of the explosive energy is used to form a crushing zone around the borehole, while some propagates outwards, creating a fracture zone. The existence of this fracture zone not only affects the damage to the surrounding rock mass caused by the explosive gases, reducing the extent of rock mass damage, but the fractures within the fracture zone also affect the mechanical properties of the surrounding rock mass, reducing its bearing capacity. Therefore, accurately and efficiently predicting the radius of the fracture zone in rock mass after blasting is of great significance for improving the utilization rate of explosive energy and reducing construction costs.

[0003] Current methods for determining the radius of the rock blast fracture zone generally employ laboratory tests, theoretical and empirical formula calculations, or numerical simulations. Laboratory tests require drilling and preparing core samples, consuming significant time and resources, and cannot fully reflect the geostress environment of the rock mass in the in-situ engineering project. Theoretical and empirical formula calculations and numerical simulations both use fixed parameters to calculate the radius of the blast fracture zone, resulting in inherent errors. This is because rock blasting is a brief and complex process, with uncertainties in the parameters of the explosive and the load generated by the explosion. Furthermore, the spatial distribution of rock masses in actual engineering projects is often non-uniform and anisotropic; therefore, rock parameters cannot be considered deterministic variables.

[0004] In summary, the explosive detonation process and the physical and mechanical properties of the rock mass itself are both very complex. Therefore, it is essential to develop a method that can not only take into account the uncertainties of blasting parameters and soil and rock parameters, but also accurately and efficiently determine the radius of the rock blasting fracture zone. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a method based on probabilistic calculation and analysis, employing a combination of single-hole and cross-hole acoustic wave detection methods and field tests to obtain the longitudinal wave velocity, borehole radius, explosive density, and detonation velocity of the rock mass, thereby rapidly determining the radius of the rock blast fracture zone. This method aims to solve the problems of high cost, complex operation, and inaccurate calculation results in existing methods for determining the radius of the rock blast fracture zone.

[0006] This invention provides a method for probabilistic calculation and analysis of the radius of rock fracture zone, comprising the following steps:

[0007] Three test boreholes, arranged in an equilateral triangle, were drilled vertically on the flat surface of the rock mass.

[0008] In the three test boreholes, the single-hole and cross-hole acoustic wave detection methods are used to obtain the P-wave velocity of the rock mass;

[0009] The radius of the three test boreholes is measured and counted;

[0010] The explosive density and explosive detonation velocity are obtained;

[0011] The average value and standard deviation of the P-wave velocity of the rock mass, the radius of the three test boreholes, the explosive density, and the explosive detonation velocity are counted respectively, and N random samples are generated according to the distribution type of the average value and standard deviation;

[0012] The N blasting fracture zone radii are calculated by substituting the N random samples into the theoretical formula of the blasting fracture zone radius;

[0013] The exceeding probability that the N blasting fracture zone radii are greater than the set blasting fracture zone radius is counted;

[0014] The set blasting fracture zone radius is changed, and the exceeding probability that the N blasting fracture zone radii are greater than the set blasting fracture zone radius is counted again;

[0015] The curve of the exceeding probability changing with the set blasting fracture zone radius is drawn to determine the rock blasting fracture zone radius.

[0016] Further, the three test boreholes include test borehole I, test borehole II, and test borehole III;

[0017] On the flat surface of the rock mass, the equilateral triangle formed by the three test boreholes has a side length of 1-2 m.

[0018] Further, the P-wave velocity of the rock mass is obtained, specifically including:

[0019] Based on the single-hole acoustic wave detection method, water is injected into the test borehole I until water overflows from the orifice;

[0020] The one-transmitting and two-receiving integrated transducer of the ultrasonic detection analyzer is arranged in the test borehole I, and the one-transmitting and two-receiving transducer is composed of an ultrasonic signal transmitting transducer, an ultrasonic signal receiving transducer I, and an ultrasonic signal receiving transducer II, wherein the ultrasonic signal transmitting transducer is arranged at the bottom of the test borehole I, the ultrasonic signal receiving transducer I and the ultrasonic signal receiving transducer II are arranged above the transmitting transducer from top to bottom, the distance between the ultrasonic signal receiving transducer I and the ultrasonic signal receiving transducer II is 20 cm, and the vertical distance between the ultrasonic signal transmitting transducer and the ultrasonic signal receiving transducer II is 30 cm;

[0021] The ultrasonic detection analyzer is operated for testing;

[0022] The data collected by the ultrasonic detection analyzer is saved, and each pair of measurement readings is read for 3 times, the relative error of the maximum reading is not more than 3%, and the wave velocity C1 at this time is recorded;

[0023] The above process is repeated to obtain the rock mass longitudinal wave velocity C2 of the test blast hole II and the rock mass longitudinal wave velocity C3 of the test blast hole III.

[0024] Further, the longitudinal wave velocity of the rock mass is obtained, and further includes:

[0025] Based on the cross-hole acoustic wave detection method, water is injected into the test blast hole I, the test blast hole II and the test blast hole III until the water overflows from the hole;

[0026] The ultrasonic signal transmitting transducer is arranged at the bottom of the test blast hole I, the ultrasonic signal receiving transducer III is arranged at the bottom of the test blast hole II, and the ultrasonic signal receiving transducer IV is arranged at the bottom of the test blast hole III;

[0027] The ultrasonic detection analyzer is operated for detection;

[0028] The data collected by the ultrasonic detection analyzer is saved, and each pair of measurement readings is read for 3 times, the relative error of the maximum reading is not more than 3%, and the wave velocity C 1-2 and C 1-3 ;

[0029] The positions of the ultrasonic signal transmitting transducer and the ultrasonic signal receiving transducer are changed, and the above process is repeated to measure the wave velocities C 2-1 , C 2-3 , C 3-1 and C 3-2 .

[0030] Further, the radius of the test blast hole I, the test blast hole II and the test blast hole III is 1.5-2.0 times the maximum radius of the ultrasonic signal transmitting transducer and the ultrasonic signal receiving transducer;

[0031] The hole depth of the test blast hole I, the test blast hole II and the test blast hole III is 2-5m in the soil layer and 8-15m in the rock layer.

[0032] Further, the radius of the three test blast holes is measured and counted, and specifically includes:

[0033] The diameter of the hole of each test blast hole is measured by a steel ruler, and the value of the radius of the test blast hole is recorded and counted.

[0034] Further, the density and detonation velocity of the explosive are obtained, and specifically include:

[0035] The density of the explosive is obtained through the information provided by the explosive manufacturer and the physical property test;

[0036] The detonation velocity of the explosive was obtained using methods such as detonation cord method, electrical measurement method, high-speed photography method, and information provided by the explosive manufacturer.

[0037] Furthermore, the generation of N random samples specifically includes:

[0038] Analyze the characteristics of existing data, including but not limited to the mean and standard deviation, select the probability distribution type, including but not limited to the normal distribution and the Weiber distribution, and randomly generate N variable samples.

[0039] Furthermore, the calculated radii of the N burst fracture zones specifically include:

[0040] radius r of the rock mass blast fracture zone c From the peak value of the explosion pressure load P b The test borehole radius r0, the stress concentration factor k of the sharp crack in the fracture zone, and the tensile strength T of the rock mass are determined by the following formula:

[0041]

[0042] In the formula, the stress concentration factor k of the sharp crack in the fracture zone is a constant, generally taken as 1.12;

[0043] Peak explosion pressure load P b Determined by the density and detonation velocity of the explosive, as shown in the following formula:

[0044]

[0045] In the formula, ρ is the density of the explosive; D CJ γ is the detonation velocity of the explosive; λ is the decoupling coefficient, which is 1 when the charge is coupled; γ is generally 3.

[0046] The tensile strength T of the rock mass is determined by the longitudinal wave velocity of the rock mass, as shown in the following formula:

[0047]

[0048] In the formula, T is the tensile strength; C p The longitudinal wave velocity is denoted by ; a and b are constants, where a is related to the rock properties and ranges from 2 × 10⁻⁶. -7 ~1×10 -6 b is 2;

[0049] Based on the above formula, the commonly used expression for the radius of the burst fracture zone is determined as follows:

[0050]

[0051] Substituting the variable samples of longitudinal wave velocity, test borehole radius, explosive density, and detonation velocity of N rock masses into the above formula, we obtain the radii of N blast fracture zones.

[0052] Further, the exceeding probability of the statistical N blasting fissure zone radiuses greater than the set blasting fissure zone radius specifically comprises:

[0053] The sample number n greater than the set blasting fissure zone radius r is counted, and then the exceeding probability of the sample number n greater than the set blasting fissure zone radius r is calculated.

[0054]

[0055] The value of the total sample number N is increased until the exceeding probability P no longer changes with the increase of N, and the exceeding probability P is the exceeding probability of the value greater than the certain rock blasting fissure zone radius r.

[0056] Compared with the prior art, the rock blasting fissure zone radius probability calculation and analysis method provided by the present application has the beneficial effects that:

[0057] The present application relates to a rock blasting fissure zone radius prediction method, more specifically to a rock blasting fissure zone radius probability calculation and analysis method, which quickly calculates the rock blasting fissure zone radius through field test, measurement and statistical method; the calculation method of random sampling statistics is used to estimate the result, the data are processed through the probability analysis method, the value range of the value greater than a certain rock blasting fissure zone radius value is calculated, which is closer to the actual situation of the engineering site and increases the accuracy of the calculation result; the method of the present application is suitable for the reasonable and efficient measurement of the rock blasting fissure zone radius in engineering construction, is more convenient to operate than the traditional method, and considers the uncertainty of the rock and soil parameters and the blasting parameters, so that the measurement result is more real and reliable. BRIEF DESCRIPTION OF DRAWINGS

[0058] Figure 1 A test blast hole distribution plan is provided for the embodiment of the present application;

[0059] Figure 2 A test blast hole distribution profile is provided for the embodiment of the present application;

[0060] Figure 3 A rock blasting zoning diagram is provided for the embodiment of the present application;

[0061] Figure 4 A flowchart of the rock blasting fissure zone radius probability calculation and analysis method provided by the present application is provided;

[0062] Figure 5 The change rule of the exceeding probability P with the blasting fissure zone radius r is provided for the embodiment of the present application.

[0063] In the figure: 1-test hole I; 2-test hole II; 3-test hole III; 4-rock mass flat surface; 5-ultrasonic signal receiving transducer I; 6-ultrasonic signal receiving transducer II; 7-ultrasonic signal transmitting transducer; 8-ultrasonic signal receiving transducer III; 9-ultrasonic signal receiving transducer IV; 10-cable. DETAILED DESCRIPTION

[0064] The specific embodiments of the present application are further described below. Figures 1 to 5 The following examples are only used to more clearly illustrate the technical solutions of the present application, and cannot be used to limit the protection scope of the present application.

[0065] Example 1: As shown in the figure, the present application provides a rock blasting fracture zone radius probability calculation and analysis method, which specifically comprises the following steps: Figures 1-5

[0066] Step 1: vertically drilling three test blast holes in an equilateral triangle distribution on the flat surface of the rock mass, wherein the three test blast holes include: test blast hole I, test blast hole II, and test blast hole III;

[0067] Step 2: using single-hole and cross-hole acoustic wave detection methods to obtain the longitudinal wave velocity of the rock mass;

[0068] Step 3: through on-site measurement, the radius of the test blast hole is counted;

[0069] Step 4: according to the explosive detonation parameters provided by the manufacturer and the on-site test of the initiating explosive device, the density and detonation velocity of the explosive are obtained;

[0070] Step 5: the characteristics (mean and standard deviation) of the existing data are counted, and the probability distribution type is selected, such as normal distribution, Weibull distribution, but not limited to this, and N variable samples are randomly generated;

[0071] Step 6: substituting the N random samples of each parameter into the commonly used blasting fracture zone radius theoretical formula, N blasting fracture zone radii are calculated;

[0072] Step 7: the exceeding probability of N blasting fracture zone radii greater than a certain determined fracture zone radius is counted; a certain determined fracture zone radius is changed, and the change curve of the exceeding probability with a certain determined fracture zone radius is drawn, to determine the rock blasting fracture zone radius.

[0073] The main principle of the present application is as follows:

[0074] (1) The rock mass blasting fracture zone radius r c is determined by the peak value of the explosion pressure load P b , the test blast hole radius r0, the sharp crack stress concentration coefficient k of the fracture zone, and the tensile strength T of the rock mass, and the commonly used calculation formula is as follows: ​

[0075]

[0076] In the formula, the stress concentration coefficient k of the sharp crack in the fissure zone is a constant, generally taken as 1.12.

[0077] The peak value of the explosive pressure load P b Determined by the explosive density and the detonation velocity, as follows:

[0078]

[0079] In the formula, p is the explosive density; D CJ is the detonation velocity of the explosive; λ is the decoupling coefficient, taken as 1 when the charge is coupled; γ is generally taken as 3.

[0080] The tensile strength T of the rock mass is determined by the longitudinal wave velocity of the rock mass, as follows:

[0081]

[0082] In the formula, T is the tensile strength; C p is the longitudinal wave velocity; a and b are constants, a is related to the properties of the rock, and the value range is 2×10 -7 ~ 1×10 -6 , and b is taken as 2.

[0083] According to the above formula, the expression of the radius of the common blasting fissure zone is determined as follows:

[0084]

[0085] (2) Assuming that r is the set radius of the blasting fissure zone, since the explosive detonation process and the physical and mechanical properties of the rock mass are very complex, the longitudinal wave velocity C p of the rock mass, the test borehole radius r0, the explosive density p and the detonation velocity D CJ are regarded as random variables obeying normal distribution. Let α = r - r c When α < 0, it is indicated that the radius r c of the rock blasting fissure zone calculated from the random variables is greater than the determined radius r of the rock blasting fissure zone. Assuming that the total number of samples of the random variables is N, and the calculation results of n samples are less than 0, i.e. α < 0, then P(α < 0) = n / N. In order to ensure the accuracy of the probability P, the number of the total number of samples N is increased until the probability P is no longer sensitive to the increase of N, at this time, P is the probability of determining the radius r of the rock blasting fissure zone. Similarly, by changing the value of r, the probability exceeding different blasting fissure zone radii can be obtained.

[0086] The specific description of the above steps 1-7 is as follows:

[0087] (1) In the flat surface of the rock mass, three tests are drilled vertically, respectively marked as test blast hole I, test blast hole II, and test blast hole III. The center line of the three test blast holes forms an equilateral triangle, and the side length is generally 1-2 m. The radius of the test blast hole is generally 1.5-2.0 times greater than the maximum radius of the acoustic detection probe. The hole depth in the soil layer is preferably 2-5 m, and the hole depth in the rock layer is preferably 8-15 m.

[0088] (2) The single-hole and cross-hole acoustic detection methods are used to obtain the longitudinal wave velocity of the rock mass. In the single-hole acoustic detection method, water is injected into the test blast hole I until water spills out of the hole. A one-transmitting and two-receiving integrated transducer of the ultrasonic detection analyzer is arranged in the same test blast hole I. The one-transmitting and two-receiving transducer is composed of one transmitting transducer and two receiving transducers. The transmitting transducer is arranged at the bottom of the test blast hole I, and the two receiving transducers are arranged at positions above the transmitting transducer. The distance between the two receiving transducers (L1) is generally 20 cm, and the vertical distance between the transmitting transducer and the closer receiving transducer (L2) is 30 cm. The ultrasonic detection analyzer is operated for testing. In the cross-hole acoustic detection method, water is injected into the test blast holes I, II, and III until water spills out of the holes. The transmitting transducer is arranged at the bottom of the test blast hole I, and one receiving transducer is arranged at the bottom of each of the test blast holes II and III. The ultrasonic tester is operated for detection. The data collected by the ultrasonic detection analyzer is saved, and each pair of measurement readings is read three times. The relative error of the maximum reading is not greater than 3%. Similarly, the positions of the transmitting and receiving transducers are changed, and the wave velocity is recorded.

[0089] (3) The diameter of the hole mouth of each test blast hole is measured with a steel ruler, and the value of the test blast hole radius is recorded and counted.

[0090] (4) The density of the explosive is obtained based on the explosive detonation parameters provided by the manufacturer and the field test of the pyrotechnic equipment. The detonation velocity of the explosive is obtained by using the detonating cord method, the electric measurement method, the high-speed photography method, and the information provided by the explosive manufacturer.

[0091] (5) The characteristics of the existing data are counted, and the average value μ and the standard deviation σ of each parameter are calculated. i i It is assumed that each random variable follows a normal distribution. Here, the variable samples are randomly generated according to the normal distribution, but it is not limited to the normal distribution. It can also be other distribution functions, and N variable samples are randomly generated.

[0092] (6) N variables are substituted into equation (4) to obtain N blasting fracture zone radii. Then, the calculated blasting fracture zone radius values are substituted into equation (5) to count the number of samples n with α < 0. The probability P = n / N that exceeds the set blasting fracture zone radius can be obtained. Increase the total number of samples N until the probability P no longer changes with the increase of N. At this time, P is the probability of exceeding the determined rock mass blasting fracture zone radius r, which is denoted as the exceeding probability.​

[0093]

[0094] (7) Change the value of r, get more than the radius of different blasting fracture zone probability P, with different blasting fracture zone radius as the horizontal axis, the probability P as the vertical axis, draw the curve of the probability with the radius of the blasting fracture zone, see Figure 5 , according to the curve, the radius of the blasting fracture zone of the rock can be obtained.

[0095] Example 2: The following specific, a rock blasting fracture zone radius probability calculation and analysis method provided in example 1 is verified, including the following steps:

[0096] (1) mark the center point position of test hole I, test hole II and test hole III on the flat surface of rock mass, the test hole plane distance is set to 2m, and the center point of the three test holes is connected to form an equilateral triangle. According to the marked position, test hole I, test hole II and test hole III are drilled, and the drilling depth is set to 8m.

[0097] (2) the single hole acoustic wave detection method, water is injected into test hole I until the water overflows from the hole, and a one-shot double-receiving integrated transducer of ultrasonic detection analyzer is arranged in the same test hole I. The one-shot double-receiving transducer is composed of one transmitting transducer and two receiving transducers, wherein the transmitting transducer is arranged at the bottom of the test hole I, and the two receiving transducers are arranged at the position above the transmitting transducer. Generally, the distance (L1) between the two receiving transducers is 20cm, and the vertical distance (L2) between the transmitting transducer and the closer receiving transducer is 30cm. The ultrasonic detection analyzer is operated for testing. When the instrument display shows stable and clear data, the data is collected and saved. Each pair of measurement is read three times, and the relative error of the maximum reading is not more than 3%. The longitudinal wave velocity C1 at this time is calculated and recorded. Similarly, C2 and C3 can be measured. See Figure 1 and Figure 2 .

[0098] Considering the complex geological conditions on site, in order to improve the accuracy of measurement, the cross hole acoustic wave detection method is used, water is injected into test hole I, II and III until the water overflows from the hole, the transmitting transducer is arranged at the bottom of test hole I, one receiving transducer is arranged at the bottom of test hole II and III respectively, and the ultrasonic tester is operated for detection; the data collected by the ultrasonic detection analyzer is saved, and each pair of measurement is read three times, and the relative error of the maximum reading is not more than 3%. The wave velocity C 1-2 and C 1-3 at this time are recorded. Similarly, by changing the position of the transmitting and receiving transducers, C 2-1 , C 2-3 , C 3-1 and C3-2 The measured data are shown in Table 1.

[0099] (3) The diameters of the test hole orifices were measured by using a steel ruler, and the values of the test hole radius are shown in Table 1.

[0100] (4) The density of the explosive was obtained according to the explosive detonation parameters provided by the manufacturer and the field test of the initiating explosive device. The detonation velocity of the explosive was obtained by using the detonating cord method, the electric measurement method, the high-speed photography method and the information provided by the explosive manufacturer. The obtained data are shown in Table 1.

[0101] (5) The longitudinal wave velocity of the rock mass, the test hole radius, the density and the detonation velocity of the explosive determined by the field test and the related test were counted, and the average value μ and the standard deviation σ of each variable were calculated, as shown in Table 1.

[0102] Table 1 Average value and standard deviation of each variable

[0103]

[0104] According to the characteristics of the variables, it was assumed that each variable obeys the normal distribution. According to the average value μ and the standard deviation σ of each random variable in Table 1, 20 random samples were generated according to the normal distribution, and r was calculated according to formula (4). c According to the field blasting parameters and the properties of the rock, the coupling charge λ was taken as 1, and a was taken as 2.59×10 -7 The randomly generated sample values are shown in Table 2.

[0105] Table 2 Randomly generated sample values

[0106] C p (m / s) [r0(m)] ρ (kg / m3) 3 )]]> D CJ (m / s) r c ]]> 3885.00 0.0416 1089.32 4898.73 1.347 3932.20 0.0467 823.46 5407.57 1.434 4716.04 0.0530 950.66 5181.38 1.397 3436.39 0.0444 1001.52 4752.02 1.512 3807.84 0.0468 780.53 5167.91 1.381 4026.36 0.0484 1060.32 5000.68 1.523 3879.33 0.0495 981.81 4839.57 1.506 4554.03 0.0532 1192.10 4673.54 1.467 3682.22 0.0506 1034.54 4837.89 1.664 3680.15 0.0538 1029.24 5166.26 1.885 3435.35 0.0487 1104.56 4525.64 1.659 4477.14 0.0473 919.32 5126.75 1.278 4059.35 0.0429 1067.50 5135.98 1.380 3948.77 0.0484 935.81 5147.00 1.502 4505.10 0.0353 1008.79 5240.72 1.015 3873.23 0.0494 965.09 5112.77 1.576 3261.12 0.0357 921.51 4111.72 1.063 3864.74 0.0305 891.56 4348.47 0.797 3907.88 0.0460 950.40 5317.84 1.502 3835.29 0.0446 950.09 5347.22 1.491

[0107] (6) It was assumed that the radius of the fracture zone r = 1.50 m, the number of samples with α < 0 was counted, and was denoted as n. According to Table 2, n = 9, and according to P = n / N, P = 9 / 20 = 0.45. Since the total number of samples is small, P is not a constant value at this time. The total number of samples was increased, and the value of P was calculated until the value of P tended to be stable. Here, the values of P when the total number of samples was 20, 100, 500, 1000, 5000 and 10000 were calculated, and the details are shown in Table 3. In Table 3, with the increase of the total number of samples N, the probability P finally stabilizes at about 0.257, and since |0.2571-0.2574| < 0.001, the probability of being greater than the radius of the fracture zone 1.5 m is 0.2571. By changing the value of r, the probability of being greater than different values of the radius of the fracture zone r can be obtained. Taking r as the abscissa and the probability P of being greater than r as the ordinate, the curve of the probability P changing with the radius of the fracture zone r was drawn, as shown in FIG. 2. Figure 5 Figure 5 ​With the increase of r value, the probability P gradually decreases, when r is 0.8, the exceeding probability is 1, when r is 1.9, the exceeding probability is 0.00997, when r is 2, the exceeding probability is 0, the crack zone radius calculated by the probability analysis method is between 0.8-2.0m. If the exceeding probability P i ≥0.99, the corresponding crack zone radius range is 0.8-0.9m; if P i ≥0.75, the corresponding crack zone radius range is 0.8-1.2m; similarly, according to the exceeding probability of the given value, the corresponding crack zone radius range can be obtained.

[0108] Table 3: the probability of exceeding r corresponding to different sample sizes

[0109] Total number of samples N greater than r c the number of samples n P i ]]> 20 9 0.45 100 41 0.41 500 182 0.364 1000 282 0.282 5000 1287 0.2574 10000 2571 0.2571

[0110] In summary, the rock blasting crack zone radius probability calculation and analysis method provided by the application has the following beneficial effects compared with the prior art:

[0111] The application relates to a rock blasting crack zone radius prediction method, in particular to a rock blasting crack zone radius probability calculation and analysis method, which quickly calculates the rock blasting crack zone radius through the methods of field test, measurement and statistics; the calculation method of random sampling statistics is used to estimate the result, the data are processed through a probability analysis method, the value range greater than a certain rock blasting crack zone radius value is calculated, the method is closer to the actual engineering site, and the accuracy of the calculation result is increased; the method is suitable for reasonable and efficient measurement of the rock blasting crack zone radius in engineering construction, is more convenient to operate than a traditional method, and is more real and reliable in measurement result considering the uncertainty of rock and soil parameters and blasting parameters.

[0112] The above-described embodiments are only the preferred specific implementation of the application, the protection scope of the application is not limited to this, any skilled person in the art can obtain the simple changes or equivalent replacements of the technical solutions in the technical range disclosed by the application, and the simple changes or equivalent replacements all belong to the protection scope of the application.

Claims

1. A method for probabilistic calculation and analysis of a rock blasting fracture zone radius, characterized in that, The method comprises the following steps: vertical drilling of three test blast holes in an equilateral triangle distribution on the rock mass flat surface (4); obtaining the longitudinal wave velocity of the rock mass by using single-hole and cross-hole acoustic detection methods in the three test blast holes; measuring and counting the radii of the three test blast holes; obtaining the explosive density and the explosive detonation velocity; counting the average values and standard deviations of the longitudinal wave velocity of the rock mass, the radii of the three test blast holes, the explosive density and the explosive detonation velocity respectively, and generating N random samples according to the distribution types of the average values and standard deviations; calculating N blast fracture zone radii by substituting the N random samples into the theoretical formula of the blast fracture zone radius; counting the exceeding probability of N blast fracture zone radii greater than the set blast fracture zone radius; changing the set blast fracture zone radius and counting again the exceeding probability of N blast fracture zone radii greater than the set blast fracture zone radius; drawing a curve of the change of the exceeding probability with the set blast fracture zone radius to determine the rock blasting fracture zone radius.

2. The method according to claim 1, wherein: the three test blast holes comprise test blast hole I (1), test blast hole II (2) and test blast hole III (3); the equilateral triangle formed by the three test blast holes on the rock mass flat surface (4) has a side length of 1-2 m.

3. The method of claim 1, wherein, The method for obtaining the longitudinal wave velocity of the rock mass comprises the following steps: based on the single-hole acoustic detection method, water is injected into the test blast hole I (1) until water overflows from the hole; an ultrasonic detection analyzer is arranged in the test blast hole I (1), and a one-transmitting and two-receiving integrated transducer is composed of an ultrasonic signal transmitting transducer (7), an ultrasonic signal receiving transducer I (5) and an ultrasonic signal receiving transducer II (6), wherein the ultrasonic signal transmitting transducer (7) is arranged at the bottom of the test blast hole I (1), the ultrasonic signal receiving transducer I (5) and the ultrasonic signal receiving transducer II (6) are arranged above the transmitting transducer from top to bottom, the distance between the ultrasonic signal receiving transducer I (5) and the ultrasonic signal receiving transducer II (6) is 20 cm, and the vertical distance between the ultrasonic signal transmitting transducer (7) and the ultrasonic signal receiving transducer II (6) is 30 cm; the ultrasonic detection analyzer is operated for testing; the data collected by the ultrasonic detection analyzer are saved, each pair of readings is read for three times, the relative error of the maximum reading is not greater than 3%, and the wave velocity C1 at this time is recorded; the above process is repeated to obtain the longitudinal wave velocity C2 of the rock mass in the test blast hole II (2) and the longitudinal wave velocity C3 of the rock mass in the test blast hole III (3).

4. The method of claim 3, wherein, The method for obtaining the longitudinal wave velocity of the rock mass further comprises the following steps: based on the cross-hole acoustic detection method, water is injected into the test blast hole I (1), the test blast hole II (2) and the test blast hole III (3) until water overflows from the holes; the ultrasonic signal transmitting transducer (7) is arranged at the bottom of the test blast hole I (1), the ultrasonic signal receiving transducer III (8) is arranged at the bottom of the test blast hole II (2), and the ultrasonic signal receiving transducer IV (9) is arranged at the bottom of the test blast hole III (3); the ultrasonic detection analyzer is operated for testing; The data collected by the ultrasonic testing analyzer is saved, and each pair of measurement readings is read 3 times, the relative error of the maximum reading is not more than 3%, and the wave velocity C at this time is recorded 1-2 with C 1-3 ; The above process is repeated by changing the positions of the ultrasonic wave transmitting transducer and the ultrasonic wave receiving transducer to measure wave velocities C 2-1 , C 2-3 , C 3-1 , and C 3-2 .

5. The method of claim 4, wherein: the radii of the test hole I (1), the test hole II (2) and the test hole III (3) are 1.5-2.0 times the maximum radius of the ultrasonic wave transmitting transducer and the ultrasonic wave receiving transducer; the depths of the test hole I (1), the test hole II (2) and the test hole III (3) are 2-5 m in the soil layer and 8-15 m in the rock layer. The method further comprises: measuring and counting the radii of the three test holes, specifically comprising: measuring the diameters of the orifices of the test holes with a steel ruler, and recording and counting the values of the radii of the test holes. The method further comprises: obtaining the density and the detonation velocity of the explosive, specifically comprising: obtaining the density of the explosive through information provided by the explosive manufacturer and physical property tests; and obtaining the detonation velocity of the explosive through the detonating cord method, the electric measurement method, the high-speed photography method and information provided by the explosive manufacturer.

6. The method of claim 1, wherein, The method further comprises: generating N random samples, specifically comprising: counting the characteristics of the existing data, including but not limited to the mean value and the standard deviation, selecting the probability distribution type, including but not limited to the normal distribution and the Weibull distribution, and randomly generating N variable samples. The method further comprises: calculating N blasting fracture zone radii, specifically comprising: substituting the variable samples of the longitudinal wave velocities of the N rock masses, the radii of the test holes, the densities of the explosives and the detonation velocities into the above formula to obtain the N blasting fracture zone radii.

7. The method of claim 1, wherein, The method further comprises: counting the exceeding probability of the N blasting fracture zone radii being greater than the set blasting fracture zone radius, specifically comprising: counting the sample number n greater than the set blasting fracture zone radius r, and then counting the exceeding probability of the sample number n greater than the set blasting fracture zone radius r as: The method further comprises: increasing the value of the total sample number N until the exceeding probability P no longer changes with the increase of N, and then the exceeding probability P is the exceeding probability of being greater than a certain determined rock blasting fracture zone radius r. The method further comprises: increasing the value of the total sample number N until the exceeding probability P no longer changes with the increase of N, and then the exceeding probability P is the exceeding probability of being greater than a certain determined rock blasting fracture zone radius r.

8. The method of claim 1, wherein, ​ ​ 9. The method of claim 1, wherein, ​ r = r0kT / P c r = r0kT / P b r = r0kT / P ​ Peak pressure load P b Determined from the density and detonation velocity of the explosive, as follows: where p is the density of the explosive; D CJ is the detonation velocity of the explosive; λ is the decoupling coefficient, which is taken as 1 when the charge is coupled; γ is taken as 3; ​ In the formula, T is tensile strength; C p is longitudinal wave velocity; a, b are constants, a is related to rock properties and has a value range of 2 x 10 -7 ~ 1 x 10 -6 , and b is 2; ​ ​ 10. The method of claim 1, wherein, ​ ​ ​

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