A method for predicting blasting vibration velocity in interbedded soft and hard rock slopes

Abstract

This invention provides a method for predicting blasting vibration velocity on interbedded soft and hard rock slopes, comprising the following steps: conducting field blasting tests on interbedded soft and hard rock slopes to obtain blasting vibration velocity data; sampling rocks for the interbedded soft and hard rock slopes and obtaining the physical and mechanical parameters of the rocks in the field through indoor mechanical tests; establishing a finite element numerical model based on the physical and mechanical parameters; verifying the simulation results of the finite element numerical model using the blasting vibration velocity data; supplementing with different working conditions to establish numerical models under different working conditions and calculating the vibration velocity results; and combining the dimensional homogeneity theorem with formula fitting based on the vibration velocity results to obtain a mathematical prediction model for blasting vibration velocity considering blasting parameters and slope attitude. This invention has significant practical significance and engineering application value for solving problems related to the prevention of geological disasters in slope engineering.

Description

Technical Field

[0001] This invention relates to the field of blasting engineering technology, and in particular to a method for predicting blasting vibration velocity on interbedded soft and hard rock slopes. Background Technology

[0002] With the rapid improvement of my country's economic level, the country has vigorously developed infrastructure construction to promote people's livelihood, resulting in a surge of rock slope engineering projects in transportation, mining, hydropower, and other production and construction fields. While blasting, as a necessary means for rock excavation and ore mining, brings significant benefits, the vibration disturbance effect of blasting is often a major contributing factor to slope instability. Furthermore, due to tectonic forces and weathering erosion, the internal structure of rock strata is complex, often accompanied by interlayers of soft and hard rock. The mechanical strength of these soft rock interlayers is far lower than that of intact rock blocks, and during slope instability, sliding often occurs along these weak interlayers, leading to overall slippage and collapse.

[0003] Existing research shows that most methods for predicting slope instability under blasting vibration do not consider the internal structure of the slope, and there is limited research on slopes with interbedded soft and hard rock. Furthermore, the requirements for controlling the vibration velocity of rock slopes under blasting loads do not take into account the influence of slope attitude. In summary, methods for predicting vibration velocity on interbedded soft and hard rock slopes under blasting loads do not comprehensively consider multiple factors such as slope attitude and load magnitude, making it difficult to provide a scientifically sound basis for blasting engineering construction and earthquake protection. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the prior art, the present invention provides a method for predicting the blasting vibration velocity of interbedded soft and hard rock slopes, which effectively solves the problem that the existing methods for predicting the vibration velocity of interbedded soft and hard rock slopes under blasting load do not comprehensively consider multiple factors such as slope attitude and load magnitude.

[0005] This invention provides a method for predicting blasting vibration velocity on a slope with interbedded soft and hard rock, comprising the following steps:

[0006] S1. Select a slope with alternating layers of soft and hard rock and conduct an on-site blasting test to obtain the blasting vibration velocity data of the alternating layers of soft and hard rock.

[0007] S2. Rock samples were taken from the interbedded soft and hard rock slope, and the physical and mechanical parameters of the rocks in the field were obtained through indoor mechanical tests.

[0008] S3. Establish a finite element numerical model based on the physical and mechanical parameters, verify the simulation results of the finite element numerical model using the blasting vibration velocity data, and then supplement different working conditions to establish numerical models under different working conditions and calculate the vibration velocity results.

[0009] S4. Combining the dimensional homogeneous theorem with the vibration velocity results, a formula is fitted to obtain a mathematical prediction model for blasting vibration velocity that considers blasting parameters and slope orientation.

[0010] Preferably, step S1 specifically includes:

[0011] A typical soft and hard rock interbedded slope was selected, and vibration velocity sensors were installed at the toe, face, and top of the slope.

[0012] Blasting holes were drilled near the alternating layers of soft and hard rock slope, explosives were buried and detonated, and vibration velocity data were collected using a vibration velocity sensor.

[0013] Preferably, step S2 specifically includes:

[0014] Rock samples were taken from the interbedded soft and hard rock slope using a core drilling rig and cut into standard rock mechanics test specimens.

[0015] The propagation characteristics of sound waves in rocks are measured using an acoustic wave detector, and the physical and mechanical parameters of the rocks are determined based on these propagation characteristics.

[0016] Preferably, the physical and mechanical parameters of the rock include rock density, elastic modulus, Poisson's ratio, and shear modulus.

[0017] Preferably, step S3 specifically includes:

[0018] The ANSYS / LS-DYNA software was used to select the corresponding material models for hard rock slope, explosive plugging, soft rock slope, and explosive. The physical and mechanical parameters of the rock in step S2 were used as the parameters of each material model to establish a finite element numerical model with the same dimensional parameters as the slope in the field test.

[0019] Vibration velocity data is extracted from the same blasting vibration velocity monitoring points as in the field test on the finite element numerical model, and compared with the field test data collected by the corresponding vibration velocity sensors. If the error is within 15%, the parameter values ​​of the finite element numerical model are reasonable; if the error is greater than 15%, the material model parameters and mesh parameters of the finite element numerical model need to be adjusted until the error is within 15%.

[0020] Based on the field data, the rock mass dip angle θ, slope angle α, slope height H, soft rock layer thickness h, and number of soft rock layers n of the five types of soft and hard rock interbedded slopes were determined. The dip coefficient ω was calculated based on the rock mass dip angle θ and slope angle α. At the same time, the maximum single-hole charge Q and blast center distance R of the five types of soft and hard rock interbedded slopes were determined based on the survey and construction data.

[0021] Based on the orthogonal experimental theory, representative points were selected from the comprehensive experiment for testing. Taking into account factors such as dip coefficient ω, slope height H, soft rock layer thickness h, number of soft rock layers n, maximum single hole charge Q, and detonation center distance R, a six-factor, five-level orthogonal experimental table with different working conditions was designed.

[0022] Based on the parameters of different working conditions in the six-factor, five-level orthogonal experimental table, corresponding numerical models were established, and the vibration velocity results of each numerical model were calculated.

[0023] Preferably, in the finite element numerical model, the slope hard rock material model and the explosive plugging material model are selected from the ANSYS / LS-DYNA material library, specifically the No. 3 nonlinear plastic material model; the slope soft rock material model is selected from the ANSYS / LS-DYNA material library, specifically the No. 193 elastoplastic constitutive model; and the explosive material model is selected from the ANSYS / LS-DYNA material library, specifically the No. 8 explosive material model. The JWL equation of state is defined as the equation of state for the explosive.

[0024] Preferably, the boundaries of the finite element numerical model, except for the upper surface, are set to non-reflective boundary conditions, and the mesh size is set to be less than 0.1 to 0.125 times the wavelength.

[0025] Preferably, the finite element numerical model uses an arbitrary Lagrange-Euler algorithm to simulate the explosion and detonation process.

[0026] Preferably, step S4 specifically includes:

[0027] Considering the relationship between slope vibration attenuation and various factors, using dimensionless analysis, the slope vibration velocity and each influencing factor have the following physical relationship:

[0028] V S =Φ(Q,R,H,ω,h,n,ρ,c)

[0029] In the above formula, V s denoted as slope vibration velocity, Q as maximum single-hole charge, R as blast center distance, H as slope height, ω as slope dip coefficient, h as slope soft rock layer thickness, n as number of slope soft rock layers, ρ as rock density, and c as vibration wave propagation velocity.

[0030] According to the homogeneity theorem of dimensions, we choose Q, R, and c as dimensionless quantities, and other parameters as dimensionless quantities, resulting in the dimensionless numbers shown below:

[0031]

[0032] The formula for predicting slope vibration velocity considering multiple factors is expressed as follows:

[0033]

[0034] In the above formula, K is a coefficient related to the medium and blasting conditions; β1 is a vibration attenuation coefficient related to the maximum single-hole charge Q and the distance between the blast centers R; β2 is a vibration attenuation coefficient related to the slope height H and the distance between the blast centers R; β3 is a vibration attenuation coefficient related to the thickness h of the soft rock layer on the slope and the distance between the blast centers R; β4 is a vibration attenuation coefficient related to the slope dip coefficient ω; and β5 is a vibration attenuation coefficient related to the number of soft rock layers n on the slope.

[0035] The vibration velocity results of each numerical model in step S3 are statistically analyzed. Based on the statistical results, the slope vibration velocity prediction formula is fitted by combining the dip coefficient ω, slope height H, soft rock layer thickness h, number of soft rock layers n, maximum single hole charge Q, and blast center distance R to obtain the specific values ​​of K, β1, β2, β3, β4, and β5, thereby obtaining the mathematical prediction model of blasting vibration velocity for the soft and hard rock interlayered slope.

[0036] This invention provides a method for predicting blasting vibration velocity in interbedded soft and hard rock slopes. It proposes blasting vibration control standards based on practical blasting engineering, ensuring safe construction and slope stability. Through literature review and relevant engineering data, it determines the attitude and load parameters of different interbedded soft and hard rock slopes, demonstrating broad applicability and reliable prediction results. This invention has significant practical and engineering application value for addressing geological disaster prevention issues in slope engineering. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a flowchart of the method for predicting blasting vibration velocity in an alternating layer of soft and hard rock slopes according to an embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram of an on-site blasting test of an alternating layer of soft and hard rock slope in an embodiment of the present invention;

[0040] in, Figure 2 The correspondence between the reference numerals and components in the attached drawings is as follows:

[0041] 1. Alternating layers of soft and hard rock slope; 2. Soft rock interlayer; 3. Blast holes; 4. Explosives. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be further described clearly and completely below with reference to the accompanying drawings of the embodiments of this invention. It should be noted that the described embodiments are merely some embodiments of this invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0043] The terms "first" and "second" used in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a system, product, or device that includes a series of components or units is not limited to the listed components or units, but may optionally include unlisted components or units, or may optionally include other components or units inherent to such products or devices. In the description of this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0044] Existing research shows that most methods for predicting slope instability under blasting vibration do not consider the internal structure of the slope, and there is limited research on slopes with interbedded soft and hard rock. Furthermore, the requirements for controlling the vibration velocity of rock slopes under blasting loads do not take into account the influence of slope attitude. In summary, methods for predicting vibration velocity on interbedded soft and hard rock slopes under blasting loads do not comprehensively consider multiple factors such as slope attitude and load magnitude, making it difficult to provide a scientifically sound basis for blasting engineering construction and earthquake protection.

[0045] This invention provides a method for predicting the blasting vibration velocity of interbedded soft and hard rock slopes, effectively solving the problem that existing methods for predicting the vibration velocity of interbedded soft and hard rock slopes under blasting loads do not comprehensively consider multiple factors such as slope attitude and load magnitude. Figure 1 This invention provides a flowchart of a method for predicting blasting vibration velocity on an interbedded soft and hard rock slope. The method includes the following steps:

[0046] Step S1: Select a slope with alternating layers of soft and hard rock and conduct an on-site blasting test to obtain the blasting vibration velocity data of the slope with alternating layers of soft and hard rock, specifically including:

[0047] Figure 2 This is a schematic diagram of an on-site blasting test of an interbedded soft and hard rock slope according to an embodiment of the present invention, as shown below. Figure 2As shown, a typical alternating soft and hard rock slope 1 was selected at the engineering site. Based on the site survey and design report, and after conducting a survey of the slope's attitude, it was found that the slope height of alternating soft and hard rock slope 1 at the engineering site was 25m, the slope angle was 50°, the dip angle of the soft rock interlayer 2 was 30°, and the thickness of the soft rock layer was 50cm. Three blast holes 3 were drilled at intervals of 10m from the slope toe, with a burial depth of 8m. Each blast hole was loaded with 12kg of explosives, and the explosives used were No. 2 rock emulsion explosives.

[0048] Five blasting vibration velocity sensors were arranged at equal intervals from the toe to the top of the slope in the vertical plane between the explosive and the slope. The vibration velocity sensors were turned on and the blast holes 3 were detonated in sequence. The vibration velocity sensors collected blasting vibration velocity data of the soft and hard rock interbedded slope through on-site experiments.

[0049] Step S2: Rock sampling is conducted on the alternating soft and hard rock slope, and the physical and mechanical parameters of the rock in the field are obtained through indoor mechanical tests, specifically including:

[0050] Rock samples were taken from the alternating soft and hard rock slope using a core drilling rig. The obtained core samples were cut into cylindrical specimens with a diameter and height of 50 mm. Based on the correlation between the propagation characteristics of sound waves in the rock mass and the physical and mechanical parameters of the rock mass, the physical and mechanical parameters of the rock, including rock density, elastic modulus, Poisson's ratio, and shear modulus, were determined by measuring the propagation characteristics of sound waves in the rock.

[0051] In this embodiment of the invention, an RSM-SY6 pile acoustic wave detector is used to test rock samples. The main unit emits transverse (P) and longitudinal (S) signals of a certain frequency and wavelength. The receiving end identifies the received wave passing through the rock sample. The propagation speed of the sound wave through the rock sample can be identified in the main unit by measuring the distance and propagation time. The time it takes for the sound wave to travel from the origin point to the receiving end is taken as the total propagation time T of the sound wave through the rock sample, and the axial distance D between the two test surfaces of the rock is taken as the propagation distance. Based on the laws of sound wave propagation, the propagation speed of the sound wave in the rock sample can be calculated.

[0052]

[0053] In the above formula, V P V is the longitudinal wave propagation velocity of the rock sample. S T represents the transverse wave propagation velocity of the rock sample. P For the time it takes for a longitudinal wave to travel through a rock, T S denoted as the transverse wave travel time through the rock, and D as the axial distance between the two test surfaces of the rock.

[0054] According to the theory of elastic wave propagation, the longitudinal wave propagation velocity and the transverse wave propagation velocity have the following relationship with the rock mass dynamic parameters:

[0055]

[0056] In the above formula, E d μ is the elastic modulus of the rock. d Let ρ be the Poisson's ratio of the rock, and ρ be the density of the rock, where the rock density ρ can be measured by the mass and volume of the rock.

[0057] The Poisson's ratio μ of the rock can be derived from formula (2). d and elastic modulus E d They are respectively:

[0058]

[0059] Poisson's ratio μ of the rock d and elastic modulus E d The shear modulus G of the rock can be calculated. d for:

[0060]

[0061] S3. Establish a finite element numerical model based on the physical and mechanical parameters, verify the simulation results of the finite element numerical model using the blasting vibration velocity data, and then supplement with different working conditions to establish numerical models under different working conditions and calculate the vibration velocity results, specifically including:

[0062] A finite element numerical model was established using ANSYS / LS-DYNA software. The selection of the hard rock material model for the slope and the explosive plugging material model within the finite element numerical model was based on the ANSYS / LS-DYNA material library, specifically the No. 3 nonlinear plastic material model, *MAT_PLASTIC_KINEMATIC. This material model is suitable for selecting isotropic and kinematic hardening plasticity, including rate effects. The constitutive equations for this material model are as follows:

[0063]

[0064] In the above formula, σ y Let σ0 be the yield stress, σ0 be the initial yield stress, C and P be the strain rate parameters, and ε be the strain rate. For effective plastic strain, β is the hardening coefficient, and E P Let E be the plastic hardening modulus. P The calculation equation is as follows:

[0065]

[0066] In the above formula, E tan E is the tangent modulus, and E is Young's modulus.

[0067] In the finite element numerical model, the soft rock material model for the slope is selected from the ANSYS / LS-DYNA material library, specifically model number 193, the elastoplastic constitutive model *MAT_DRUCKER_PRAGER. This model determines the yield surface based on the friction angle and cohesion. A modified Drucker-Prager yield surface is used in this model to distort the surface shape to a more realistic soil definition. The yield surface function F is expressed as:

[0068]

[0069] In the above formula, T is the shear strength, σ m φ is the average stress, φ is the internal friction angle, and c' is the cohesion.

[0070] In the finite element numerical model, the explosive material model selected is explosive material model No. 8 from the ANSYS / LS-DYNA material library, namely the *HIGH_EXPLOSIVE_BURN material model. During the explosion, the explosive undergoes rapid chemical reactions, which can be described by multiple equations of state. The Jones-Wilkins-Lee Equation of State (JWL-EOS) is used to describe the chemical reaction process, and experimentally obtained parameters are used to predict the large-scale pressure caused by the explosion. The JWL equation of state is used to represent the relationship between pressure and specific volume during the explosive detonation process, and the relationship is as follows:

[0071]

[0072] In the above formula, P is the relative specific volume of the detonation products (the ratio of the volume of the detonation products to the initial volume of the explosive), V is the pressure of the detonation products, E0 is the internal energy per unit volume, and R1, R2, A, B, and ω are material constants.

[0073] The physical and mechanical parameters required for each material model in the embodiments of the present invention are shown in the following table:

[0074] Table 1 Physical and mechanical parameters of rocks

[0075]

[0076] In the table above, ρ represents the rock density, and E d G represents the elastic modulus of rock. d Represents the rock shear modulus, μ d The value of 'c' represents the Poisson's ratio of the rock, and 'c' represents the cohesion of the rock. σ represents the internal friction angle of the rock. tIt represents the tensile strength of the rock.

[0077] To eliminate the influence of the boundary and mesh size of the finite element numerical model, and to eliminate the reflection effect of the blast stress wave generated by the explosive blast at the boundary of the finite element numerical model, all boundaries of the finite element numerical model except the upper surface are set to non-reflective boundary conditions, and the mesh size is set to be less than 0.1 to 0.125 times the wavelength.

[0078] The Arbitrary Lagrange-Euler (ALE) algorithm is used to simulate the explosion detonation process. This algorithm allows for arbitrary movement within the mesh in space and is suitable for problems involving large spatial displacements and significant deformations of the entire object. The algorithm is configured by adding the keyword CONTROL_ALE.

[0079] Vibration velocity data were extracted from the same vibration velocity monitoring points as those in the field test on the established finite element numerical model, and compared with the vibration velocity results of the field test. If the error was within 15%, the established finite element numerical model and parameter values ​​were considered reasonable. If the error was greater than 15%, the material model parameters and mesh parameters of the finite element numerical model needed to be adjusted, and the above steps were repeated until the results were reasonable.

[0080] Based on field data and relevant literature, we determined the dip angle θ of five common interbedded soft and hard rock masses, the slope angle α of five common slopes, the slope height H of five common slopes, the thickness h of five soft rock layers, and the number n of five soft rock layers. Then, by studying construction data, we determined the maximum single-hole charge Q and the five blast center distances (distance between the seismic source and the slope toe) R for bench blasting.

[0081] Based on the dip direction of the weak interlayers, slopes can be classified into dip-slopes and reverse-slopes. The dip coefficient ω is defined and its calculation formula is as follows:

[0082]

[0083] In the above formula, θ is the dip angle of the interbedded soft and hard rock mass, and α is the slope angle of the interbedded soft and hard rock slope. When ω<1, the slope is a dip-sloping slope; when ω≥1, the slope is a reverse-dip slope.

[0084] In this embodiment of the invention, based on relevant literature review and geological survey data, the five common slope heights are determined to be 15m, 30m, 45m, 60m and 80m; the five soft rock layer numbers are 1, 2, 3, 4 and 5; the five soft rock thicknesses are 10cm, 30cm, 50cm, 75cm and 100cm; the five maximum single-hole charge amounts are 8kg, 12kg, 16kg, 20kg and 24kg; the five dip coefficients are 0.6, 0.8, 1, 1.2 and 1.4; and the five blast center distances are 10m, 15m, 20m, 25m and 30m.

[0085] Taking into account the numerical modeling under multiple factors and multiple levels of working conditions, and based on the orthogonal experimental theory, a six-factor, five-level orthogonal experimental design was conducted by selecting some representative points from the comprehensive experiment, considering the dip coefficient ω, slope height H, soft rock layer thickness h, number of soft rock layers n, maximum single-hole charge Q, and detonation center distance R. The design is as follows:

[0086] Table 2. Six-Factor Five-Level Orthogonal Experiment Table

[0087]

[0088] Based on the field test model, a numerical model is established according to each working condition number in the orthogonal experimental table. The main dimensional parameters of the numerical model are modified and assigned using the orthogonal experimental table. At the same time, the vibration velocity results of different numerical models are calculated and the obtained vibration velocity results are classified and organized.

[0089] Step S4: Combining the dimensional homogeneity theorem with the vibration velocity results, a formula is fitted to obtain a mathematical prediction model for blasting vibration velocity considering blasting parameters and slope attitude, specifically including:

[0090] Considering the relationship between slope vibration attenuation and various factors, using dimensionless analysis, we assume the following physical relationship between slope vibration velocity and each influencing factor:

[0091] V S =Φ(Q,R,H,ω,h,n,ρ,c) (10)

[0092] The physical meaning and dimensional representation of each parameter in the above formula are shown in the table below:

[0093] Table 3. Schematic diagram of relevant parameters and dimensions of slope vibration velocity.

[0094] Parameter unit dimension <![CDATA[Particle vibration velocity V S > cm / s <![CDATA[LT -1 ]]> Maximum single-stage drug dose Q kg M Explosion center distance R m L Slope height H m L Propensity coefficient ω - 1 Soft rock layer thickness h cm L Number of soft rock layers n - 1 <![CDATA[Hard rock density ρ1]]> <![CDATA[g / cm 3 ]]> <![CDATA[ML -3 ]]> <![CDATA[Soft rock density ρ2]]> <![CDATA[g / cm 3 ]]> <![CDATA[ML -3 ]]> <![CDATA[Wave velocity c1 of wave propagation in hard rock medium]]> m / s <![CDATA[LT -1 ]]> <![CDATA[Wave velocity c2 of wave propagation in soft rock medium]]> m / s <![CDATA[LT -1 ]]>

[0095] In the table above, L represents the dimension of length, T represents the dimension of time, and M represents the dimension of mass.

[0096] According to the homogeneity theorem of dimensions, if we choose Q, R, and c as dimensionless quantities and the other parameters as dimensionless quantities, we can obtain the dimensionless numbers as follows:

[0097]

[0098] The formula for predicting slope vibration velocity considering multiple factors can be expressed as:

[0099]

[0100] In the above formula, K is a coefficient related to the medium and blasting conditions; β1 is a vibration attenuation coefficient related to the maximum single-hole charge Q and the distance between the blast centers R; β2 is a vibration attenuation coefficient related to the slope height H and the distance between the blast centers R; β3 is a vibration attenuation coefficient related to the thickness h of the soft rock layer on the slope and the distance between the blast centers R; β4 is a vibration attenuation coefficient related to the slope dip coefficient ω; and β5 is a vibration attenuation coefficient related to the number of soft rock layers n on the slope.

[0101] The vibration velocity results of each numerical model in step S3 are statistically analyzed. Based on the statistical results, the slope vibration velocity prediction formula is fitted by combining the dip coefficient ω, slope height H, soft rock layer thickness h, number of soft rock layers n, maximum single-hole charge Q, and blast center distance R to obtain the specific values ​​of K, β1, β2, β3, β4, and β5. The form of the prediction formula is then improved, resulting in the following mathematical prediction model for the blasting vibration velocity of the alternating soft and hard rock slope:

[0102]

[0103] This mathematical prediction model for vibration velocity can provide a reference for predicting the vibration velocity of interbedded soft and hard rock slopes under blasting loads.

[0104] In summary, this invention provides a method for predicting blasting vibration velocity in interbedded soft and hard rock slopes. Combining practical blasting engineering, it proposes blasting vibration control standards, ensuring safe construction and slope stability in blasting projects. Through literature review and relevant engineering data, the method determines the attitude and load parameters of different interbedded soft and hard rock slopes, demonstrating broad applicability and reliable prediction results. This invention has significant practical and engineering application value for addressing technological development related to slope engineering geological hazard prevention.

[0105] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0106] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for predicting blasting vibration velocity on a slope with alternating layers of soft and hard rock, characterized in that, Includes the following steps: S1. Select a slope with alternating layers of soft and hard rock and conduct an on-site blasting test to obtain the blasting vibration velocity data of the alternating layers of soft and hard rock. S2. Rock samples were taken from the interbedded soft and hard rock slope, and the physical and mechanical parameters of the rocks in the field were obtained through indoor mechanical tests. S3. Establish a finite element numerical model based on the physical and mechanical parameters, verify the simulation results of the finite element numerical model using the blasting vibration velocity data, and then supplement different working conditions to establish numerical models under different working conditions and calculate the vibration velocity results. S4. Combining the dimensional homogeneity theorem with the vibration velocity results, a formula is fitted to obtain a mathematical prediction model for blasting vibration velocity considering blasting parameters and slope attitude; step S4 specifically includes: Considering the relationship between slope vibration attenuation and various factors, using dimensionless analysis, the slope vibration velocity and each influencing factor have the following physical relationship: In the above formula, V s Slope vibration velocity ，Q For maximum single-hole charge, R For the distance between the centers, H For the slope height, ω This is the slope dip coefficient. h For the thick soft rock layer of the slope, n This refers to the number of soft rock layers on the slope. For rock density, c Let be the propagation speed of the vibration wave; according to the homogeneity theorem of dimensions, choose . Q, R, c Let be the dimensionless quantities, and let the other parameters be the dimensionless quantities. The resulting dimensionless numbers are shown below: The formula for predicting slope vibration velocity considering multiple factors is expressed as follows: In the above formula, K A coefficient related to the medium and blasting conditions; β 1 To match the maximum single-hole charge Q and center of blast distance R The relevant vibration attenuation coefficient; β 2 To match the slope height H and center of blast distance R The relevant vibration attenuation coefficient; β 3 To match the thick soft rock layer of the slope h and center of blast distance R The relevant vibration attenuation coefficient; β 4 To be related to the slope dip coefficient ω The relevant vibration attenuation coefficient; β 5 To match the number of soft rock layers on the slope n The relevant vibration attenuation coefficient; The vibration velocity results of each numerical model in step S3 are statistically analyzed, and the results are combined with the tendency coefficient. ω , slope height H Thick soft rock layers h Number of soft rock layers n Maximum single-hole charge Q , explosion center distance R The slope vibration velocity prediction formula was fitted to obtain... K、β 1 , β 2 , β 3 , β 4 and β 5 The specific values ​​are obtained to arrive at a mathematical prediction model for the blasting vibration velocity of the alternating soft and hard rock slope.

2. The method for predicting blasting vibration velocity on interbedded soft and hard rock slopes according to claim 1, characterized in that, Step S1 specifically includes: A typical soft and hard rock interbedded slope was selected, and vibration velocity sensors were installed at the toe, face, and top of the slope. Blasting holes were drilled near the alternating layers of soft and hard rock slope, explosives were buried and detonated, and vibration velocity data were collected using a vibration velocity sensor.

3. The method for predicting blasting vibration velocity on interbedded soft and hard rock slopes according to claim 1, characterized in that, Step S2 specifically includes: Rock samples were taken from the interbedded soft and hard rock slope using a core drilling rig and cut into standard rock mechanics test specimens. The propagation characteristics of sound waves in rocks are measured using an acoustic wave detector, and the physical and mechanical parameters of the rocks are determined based on these propagation characteristics.

4. The method for predicting blasting vibration velocity on interbedded soft and hard rock slopes according to claim 3, characterized in that, The physical and mechanical parameters of the rock include rock density, elastic modulus, Poisson's ratio, and shear modulus.

5. The method for predicting blasting vibration velocity on interbedded soft and hard rock slopes according to claim 1, characterized in that, Step S3 specifically includes: The ANSYS / LS-DYNA software was used to select the corresponding material models for hard rock slope, explosive plugging, soft rock slope, and explosive. The physical and mechanical parameters of the rock in step S2 were used as the parameters of each material model to establish a finite element numerical model with the same dimensional parameters as the slope in the field test. Vibration velocity data is extracted from the same blasting vibration velocity monitoring points as in the field test on the finite element numerical model, and compared with the field test data collected by the corresponding vibration velocity sensors. If the error is within 15%, the parameter values ​​of the finite element numerical model are reasonable; if the error is greater than 15%, the material model parameters and mesh parameters of the finite element numerical model need to be adjusted until the error is within 15%. Based on on-site data, the rock mass dip angle θ, slope angle α, and slope height of the five types of interbedded soft and hard rock slopes were determined. H Thick soft rock layers h Number of soft rock layers n The dip coefficient is calculated based on the rock mass dip angle θ and slope angle α. ω, Simultaneously, based on the surveyed construction data, the maximum single-hole charge for blasting of five types of alternating soft and hard rock slopes was determined. Q , explosion center distance R ; Based on orthogonal experiment theory, representative points are selected from the full experiment for further testing, taking into account the propensity coefficient. ω , slope height H Thick soft rock layers h Number of soft rock layers n Maximum single-hole charge Q , explosion center distance R Design a six-factor, five-level orthogonal experimental table that includes different working conditions; Based on the parameters of different working conditions in the six-factor, five-level orthogonal experimental table, corresponding numerical models were established, and the vibration velocity results of each numerical model were calculated.

6. The method for predicting blasting vibration velocity on interbedded soft and hard rock slopes according to claim 5, characterized in that, In the finite element numerical model, the slope hard rock material model and the explosive plugging material model are selected from the ANSYS / LS-DYNA material library, specifically the No. 3 nonlinear plastic material model. The slope soft rock material model is selected from the ANSYS / LS-DYNA material library, specifically the No. 193 elastoplastic constitutive model. The explosive material model is selected from the ANSYS / LS-DYNA material library, specifically the No. 8 explosive material model. The JWL equation of state is defined as the equation of state for the explosive.

7. The method for predicting blasting vibration velocity on interbedded soft and hard rock slopes according to claim 5, characterized in that, The boundaries of the finite element numerical model, except for the upper surface, are set to non-reflective boundary conditions, and the mesh size is set to be less than 0.1~0.125 of the wavelength.

8. The method for predicting blasting vibration velocity on interbedded soft and hard rock slopes according to claim 5, characterized in that, The finite element numerical model uses an arbitrary Lagrange-Euler algorithm to simulate the explosion and detonation process.

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