Method for analyzing stability of weak intercalated layer side slope under blasting vibration effect

Abstract

The invention discloses a method for analyzing the stability of a weak intercalated layer slope under the action of blasting vibration, and the method comprises the steps: obtaining the single blasting dosage, the distance from a blasting point to the gravity center of a slope slide body, a blasting vibration coefficient and an attenuation index, and determining the vibration speed of the mass point of a slope rock body; according to the elastic modulus, the Poisson's ratio, the density and the rock mass integrity coefficient of the rock, the propagation speed of stress waves in the rock mass is determined; calculating dynamic normal stress and dynamic shear stress based on the vibration speed, the propagation speed of stress waves in the rock mass, the rock mass density and the included angle between the mass point vibration direction and the potential sliding surface; determining a weakening cohesion force and a weakening internal friction angle based on the initial cohesion force and the initial internal friction angle of the weak intercalated layer and a preset strength reduction coefficient; and calculating the safety coefficient according to the self weight, the dynamic normal stress, the dynamic shear stress, the weakening cohesion and the weakening internal friction angle of the sliding body. According to the method, a more reliable quantitative basis is provided for engineering design, construction control and safety early warning.

Description

Technical Field

[0001] This invention belongs to the field of slope stability analysis in geotechnical engineering, and particularly relates to a method for stability analysis of weak interlayer slopes under blasting vibration. Background Technology

[0002] Blasting is a common construction method in geotechnical engineering projects such as open-pit mines, railway and highway slopes, used for rock excavation, ore mining, or tunnel excavation. However, the vibrations generated by blasting propagate stress waves to the surrounding soil and rock media, posing a significant threat to the stability of adjacent slopes. This problem is particularly prominent in slopes containing weak interlayers (such as mudstone interlayers, fault fracture zones, and weathered rock layers). Weak interlayers typically have low strength, large deformation, and are sensitive to dynamic loads. Under repeated blasting vibrations, they are prone to strength attenuation and deformation accumulation, which can induce sliding instability along the weak surface. In severe cases, this can lead to slope collapse, road interruption, mining disruption, and even casualties, posing a significant threat to engineering safety.

[0003] Currently, the "quasi-static method" is widely used in engineering to analyze the impact of blasting vibration on slope stability. This method simplifies the blasting vibration effect into a static inertial force, usually expressed as a horizontal or vertical seismic coefficient, and applies it as an additional load to the potential sliding body. The safety factor of the slope is then calculated using limit equilibrium theory. This approach, borrowed from seismic slope stability analysis, is widely used in practice due to its simplicity and ease of calculation.

[0004] However, this method has significant limitations when simulating dynamic loads such as blasting vibration, mainly in the following aspects:

[0005] First, it fails to accurately reflect the propagation and action mechanism of blasting stress waves. Blasting is essentially a dynamic propagation process of stress waves excited by explosive energy in rock mass. On potential sliding surfaces, in addition to causing overall inertial effects of the sliding body, it directly generates dynamic normal stress and dynamic shear stress that vary with time. Traditional quasi-static methods only consider the former (i.e., inertial forces in the form of body forces) while completely ignoring the latter (i.e., wave stress in the form of surface forces), resulting in a severely distorted description of the stress state of the sliding surface.

[0006] Secondly, the dynamic weakening characteristics of weak interlayer materials are overlooked. Under cyclic dynamic loading, the shear strength parameters (cohesion and internal friction angle) of weak interlayers will decrease, i.e., a dynamic weakening effect. Traditional methods use static strength parameters for analysis, which cannot reflect the cumulative damage and weakening process of the weak interlayer strength caused by repeated blasting vibrations, and may overestimate the dynamic stability of the slope, leading to safety hazards.

[0007] Furthermore, it is impossible to accurately account for the coupling effect between the directionality of stress wave propagation and the spatial orientation of the sliding surface. The propagation of blast stress waves in rock mass is directional, and the magnitude and direction of the dynamic stress induced on the sliding surface are closely related to spatial geometric relationships such as the wave's incident angle, the sliding surface's dip angle, and its direction of dip. Traditional methods use a single-direction, constant-magnitude seismic coefficient for equivalence, which is insufficient to accurately simulate this complex three-dimensional wave stress field. The analysis results are often oversimplified and lack reliability.

[0008] In summary, existing slope stability analysis methods based on the quasi-static method, when applied to slopes with weak interlayers under blasting vibration, fail to adequately consider key factors such as the direct effect of wave stress, the dynamic weakening of material strength, and the spatial directionality of stress propagation. This leads to potentially significant deviations between the analysis results and actual conditions, making it difficult to meet the urgent needs of high-risk slope engineering for accurate stability assessment and safety control. Therefore, developing a slope stability analysis method that can more realistically reflect the characteristics of blasting vibration loads, the dynamic response of weak interlayers, and the spatial stress state has significant theoretical value and practical engineering implications. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides a method for stability analysis of weak interlayer slopes under blasting vibration, comprising the following steps:

[0010] The amount of explosives used in a single blast, the distance from the blast point to the center of gravity of the slope sliding mass, the blasting vibration coefficient and the attenuation index are obtained to determine the vibration velocity of the rock mass particles on the slope.

[0011] The propagation velocity of stress waves in the rock mass is determined based on the rock's elastic modulus, Poisson's ratio, density, and rock mass integrity coefficient.

[0012] Based on the vibration velocity, the propagation velocity of the stress wave in the rock mass, the rock mass density, and the angle between the particle vibration direction and the potential sliding surface, the dynamic normal stress and dynamic shear stress generated by the blasting vibration on the potential sliding surface as a function of time are calculated.

[0013] Based on the initial cohesion, initial internal friction angle, and preset strength reduction coefficient of the weak interlayer, the weakened cohesion and weakened internal friction angle of the weak interlayer after blasting vibration are determined.

[0014] The safety factor for evaluating slope stability is calculated based on the self-weight of the sliding body, dynamic normal stress, dynamic shear stress, weakened cohesion, and weakened internal friction angle.

[0015] Optionally, the vibration velocity of the rock mass particles on the slope is determined, specifically as follows:

[0016] The peak vibration velocity of the rock mass particles on the slope is calculated based on the amount of explosive used in a single blast, the distance from the blast point to the center of gravity of the slope sliding mass, the blast vibration coefficient and the attenuation index.

[0017] Based on the peak vibration velocity, and according to the law of sinusoidal periodic change and exponential decay over time described by the set vibration frequency, initial phase and decay index, the vibration velocity time history of the slope rock mass particles is determined.

[0018] Optionally, the dynamic normal stress and dynamic shear stress generated by the blasting vibration on the potential sliding surface as a function of time are calculated, specifically as follows:

[0019] The dynamic normal stress is generated by the action of longitudinal waves, and its instantaneous value is proportional to the rock mass density, the propagation speed of the longitudinal waves in the rock mass, and the component of the vibration velocity in the direction perpendicular to the potential sliding surface.

[0020] The dynamic shear stress is generated by the action of transverse waves, and its instantaneous value is proportional to the rock mass density, the propagation speed of the transverse waves in the rock mass, and the component of the vibration velocity in the direction parallel to the potential sliding surface.

[0021] Optionally, determining the angle between the particle vibration direction and the potential sliding surface includes:

[0022] Establish a plane coordinate system based on the slope; based on the location of the blasting source, the location of the mass point, and the geometric relationship of the sliding surface, calculate the angle between the vibration direction of the mass point and the potential sliding surface using trigonometric functions.

[0023] Optionally, the weakened cohesion and weakened internal friction angle of the weak interlayer after blasting vibration are determined, specifically as follows:

[0024] Divide the initial cohesion by the strength reduction factor to obtain the weakened cohesion;

[0025] Dividing the tangent of the initial internal friction angle by the strength reduction factor yields the tangent of the weakened internal friction angle.

[0026] Optionally, the safety factor used to evaluate slope stability is calculated, including:

[0027] Calculate the sliding force of the sliding body, which is the sum of the component of the sliding body's own weight along the sliding surface and the contribution of the dynamic shear stress on the sliding surface;

[0028] Calculate the anti-slip force of the sliding surface, wherein the anti-slip force is the product of the normal force of the sliding surface and the tangent of the weakened internal friction angle, plus the contribution of the weakened cohesion on the sliding surface; wherein the normal force of the sliding surface is the difference between the component of the sliding body's self-weight perpendicular to the sliding surface and the contribution of the dynamic normal stress on the sliding surface.

[0029] The ratio of the anti-slip force to the sliding force is used as the safety factor.

[0030] Optionally, when calculating the safety factor, the dynamic normal stress and the dynamic shear stress are used at their peak values.

[0031] On the other hand, the present invention also provides a computer device including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method.

[0032] On the other hand, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method.

[0033] On the other hand, the present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the method.

[0034] Compared with the prior art, the present invention has the following advantages and technical effects:

[0035] This invention addresses the fundamental flaw of traditional "quasi-static methods," which only consider overall inertial forces while neglecting the direct effect of wave stress, by introducing and quantifying the dynamic normal stress and dynamic shear stress directly generated by blasting vibrations on the potential sliding surface. Traditional methods equate blasting vibrations to a single, static inertial force, failing to reflect the complex stress state induced by stress waves on the sliding surface. Based on wave theory, this method directly calculates the time-varying stress acting on the sliding surface based on vibration velocity, wave velocity, rock mass density, and geometric relationships, thus providing a more realistic and precise characterization of the actual mechanism by which blasting loads affect slope stability.

[0036] This invention addresses the problem of traditional methods, which rely on static strength parameters and fail to reflect the strength degradation of materials under cyclic dynamic loading, by introducing a dynamic weakening shear strength parameter for weak interlayers based on a strength reduction factor into stability calculations. Traditional analyses neglect the high sensitivity of weak interlayers to blast vibrations, potentially significantly overestimating their dynamic strength. This method simulates the dynamic weakening effect by reducing the initial strength parameter, enabling stability assessments to consider the cumulative damage and strength degradation process of weak interlayer materials caused by blast vibrations, resulting in analysis results that are more consistent with engineering realities.

[0037] This invention integrates the aforementioned dynamic surface forces, material weakening effects, and sliding body self-weight stress into a unified limit equilibrium analysis framework, solving the problem that traditional methods, due to overly simplified load and material models, cannot accurately assess stability under complex working conditions. This method comprehensively considers body forces (self-weight inertial forces), surface forces (dynamic stress), and the time-varying characteristics of material parameters. It also introduces the angle between the particle vibration direction and the sliding surface to reflect the spatial directionality of wave stress, thereby constructing a stability analysis model that more comprehensively reflects the influence of blasting vibration, the characteristics of weak interlayers, and the geometric features of the slope.

[0038] In summary, this invention significantly improves the scientific rigor and accuracy of stability analysis for slopes containing weak interlayers under blasting vibration conditions. The calculated safety factor more accurately reflects the safety reserve of the slope under dynamic loads, providing a more reliable quantitative basis for engineering design, construction control, and safety early warning. This helps avoid engineering risks caused by analytical distortion and has significant engineering application value. Attached Figure Description

[0039] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0040] Figure 1 This is a schematic diagram of the decomposition of vibration velocity on a weak interlayered rock slope according to an embodiment of the present invention;

[0041] Figure 2 This is a simplified mechanical model of a weak interlayered rock slope according to an embodiment of the present invention.

[0042] Figure 3 This is a flowchart illustrating the safety factor calculation process according to an embodiment of the present invention.

[0043] Figure 4 This is a molar-coulomb intensity diagram of an embodiment of the present invention;

[0044] Figure 5 This is a slope profile diagram according to an embodiment of the present invention. Detailed Implementation

[0045] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0046] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0047] Example 1

[0048] This embodiment provides a stability analysis method for a weak interlayer slope under blasting vibration, including the following steps:

[0049] The amount of explosives used in a single blast, the distance from the blast point to the center of gravity of the slope sliding mass, the blasting vibration coefficient and the attenuation index are obtained to determine the vibration velocity of the rock mass particles on the slope.

[0050] The propagation velocity of stress waves in the rock mass is determined based on the rock's elastic modulus, Poisson's ratio, density, and rock mass integrity coefficient.

[0051] Based on the vibration velocity, the propagation velocity of the stress wave in the rock mass, the rock mass density, and the angle between the particle vibration direction and the potential sliding surface, the dynamic normal stress and dynamic shear stress generated by the blasting vibration on the potential sliding surface as a function of time are calculated.

[0052] Based on the initial cohesion, initial internal friction angle, and preset strength reduction coefficient of the weak interlayer, the weakened cohesion and weakened internal friction angle of the weak interlayer after blasting vibration are determined.

[0053] The safety factor for evaluating slope stability is calculated based on the self-weight of the sliding body, dynamic normal stress, dynamic shear stress, weakened cohesion, and weakened internal friction angle.

[0054] The feasible method for determining the vibration velocity of rock mass particles on the slope is as follows:

[0055] Based on the amount of explosive used in a single blast, the distance from the blast point to the center of gravity of the slope sliding mass, the blast vibration coefficient, and the attenuation index, the peak vibration velocity of the rock mass particles on the slope is calculated. Based on the peak vibration velocity, and according to the law of sinusoidal periodic change with time and exponential decay described by the set vibration frequency, initial phase, and attenuation index, the vibration velocity time history of the rock mass particles on the slope is determined.

[0056] It is feasible to calculate the time-varying dynamic normal stress and dynamic shear stress generated by blasting vibration on the potential sliding surface, specifically as follows:

[0057] The dynamic normal stress is generated by longitudinal wave action, and its instantaneous value is proportional to the rock mass density, the propagation speed of longitudinal wave in the rock mass, and the component of vibration velocity in the direction perpendicular to the potential sliding surface; the dynamic shear stress is generated by transverse wave action, and its instantaneous value is proportional to the rock mass density, the propagation speed of transverse wave in the rock mass, and the component of vibration velocity in the direction parallel to the potential sliding surface.

[0058] Implementable methods for determining the angle between the direction of particle vibration and the potential sliding surface include:

[0059] Establish a plane coordinate system based on the slope; based on the location of the blasting source, the location of the mass point, and the geometric relationship of the sliding surface, calculate the angle between the vibration direction of the mass point and the potential sliding surface using trigonometric functions.

[0060] It is feasible to determine the weakened cohesion and weakened internal friction angle of the weak interlayer after blasting vibration, specifically as follows:

[0061] Dividing the initial cohesion by the strength reduction factor yields the weakened cohesion; dividing the tangent of the initial internal friction angle by the strength reduction factor yields the tangent of the weakened internal friction angle.

[0062] The feasible calculation of the safety factor used to evaluate slope stability includes:

[0063] Calculate the sliding force of the sliding body, which is the sum of the component of the sliding body's own weight along the sliding surface and the contribution of the dynamic shear stress on the sliding surface;

[0064] Calculate the anti-slip force of the sliding surface, wherein the anti-slip force is the product of the normal force of the sliding surface and the tangent of the weakened internal friction angle, plus the contribution of the weakened cohesion on the sliding surface; wherein the normal force of the sliding surface is the difference between the component of the sliding body's self-weight perpendicular to the sliding surface and the contribution of the dynamic normal stress on the sliding surface.

[0065] The ratio of the anti-slip force to the sliding force is used as the safety factor.

[0066] Furthermore, when calculating the safety factor, the dynamic normal stress and the dynamic shear stress are used at their peak values.

[0067] On the other hand, this embodiment also provides a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method.

[0068] On the other hand, this embodiment also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method.

[0069] On the other hand, this embodiment also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the method.

[0070] Example 2

[0071] This embodiment proposes a method for analyzing the stability of a weak interlayer slope under blasting vibration, considering the attenuation of the blasting vibration process, and calculating a relatively reliable safety factor.

[0072] This embodiment decomposes the effect of the blast stress wave into dynamic normal stress and dynamic shear stress acting on the potential sliding surface, and combines this with the overall inertial force. Simultaneously, it employs strength parameters weakened by dynamic stress to construct an improved quasi-static analysis framework. Specific steps include:

[0073] Precise load decomposition: Using wave theory, the measured or predicted vibration velocity time history is converted into dynamic normal stress on the potential sliding surface. and dynamic shear stress .

[0074] Dynamic weakening of strength parameters: Based on the results of dynamic triaxial tests, dynamic strength parameters adapted to the dynamic stress level of blasting are selected. , ) is used for calculation.

[0075] Model integration and calculation: The above dynamic stress (taking its peak value) is introduced as an additional load into the limit equilibrium equation to solve for the safety factor.

[0076] like Figures 1-2 As shown, the periodic additional vibration stress on the potential landslide rock mass is the main mechanical mechanism by which underground blasting vibration degrades slope stability. Under the action of blasting vibration, the blasting vibration energy will propagate outward in the form of stress waves. During the propagation process, the stress waves will cause differential vibration of various particles inside the rock mass, thereby generating additional stress inside the rock mass. Related research results show that the additional stress generated inside the rock mass due to blasting vibration is related to the rock mass's resistance to stress waves and the vibration velocity of the particles. The additional dynamic stress of the rock mass derived from momentum theory can be expressed as:

[0077]

[0078]

[0079] In the formula: The normal stress generated by the longitudinal wave; The shear stress generated by the transverse wave; Density of the rock mass; , These represent the propagation velocities of longitudinal and transverse waves within the rock mass, respectively. , These are the vibration velocities of rock mass particles caused by longitudinal and transverse waves, respectively.

[0080] To further derive the additional dynamic stress within the rock mass under blasting vibration, it is necessary to obtain the propagation velocities of longitudinal and transverse waves within the rock mass, as well as the expressions for the vibration velocity of the particles. The particle vibration velocity changes dynamically with time; in engineering, equation (2) is commonly used to calculate the maximum particle vibration velocity:

[0081]

[0082] In the formula: K represents the maximum vibrational velocity of the particle; These are the blasting vibration coefficient and attenuation index, which are related to topography and slope geological conditions, respectively, and can be calculated by inversion using monitoring data; Q is the amount of explosive used in a single blast; and R is the distance from the blasting point to the center of gravity of the slope sliding.

[0083] Assuming that the vibration velocity of the rock mass particles varies periodically with the peak vibration velocity according to a sinusoidal law, and that the vibration velocity decays exponentially with the peak vibration velocity, then the relationship between the vibration velocity of the rock mass particles and time can be expressed as:

[0084]

[0085] In the formula: The velocity of the particle vibration; The angular frequency of the particle's vibration velocity change. =2π ; The vibration frequency; This represents the initial phase of the particle's vibrational velocity change; the meanings of the other variables are the same as above.

[0086] After obtaining the particle vibration velocity, it is necessary to further determine the propagation velocities of longitudinal and transverse waves within the rock mass. The development characteristics of joints and fissures within the rock mass have a significant impact on the propagation velocity of stress waves. However, due to the extremely complex distribution of joints and fissures within the rock mass, it is usually considered as an infinitely homogeneous medium. Through theoretical derivation, the propagation velocity of blasting vibration stress waves is related to rock density, elastic modulus, and Poisson's ratio, as shown in the following formula:

[0087]

[0088]

[0089] In the formula: The elastic modulus of the rock; This represents the Poisson's ratio of the rock; the meanings of the other variables are the same as above.

[0090] The propagation speed of stress waves within a rock mass is usually lower than that within the rock itself. To obtain the propagation speed of stress waves within a rock mass, the rock mass integrity coefficient K can be used as a basis for calculating the rock stress wave propagation speed. V The correction is expressed as follows:

[0091]

[0092] In the formula: This is the rock mass integrity coefficient.

[0093] Substituting equation (5) into equation (4), and equation (2) into equation (3), and finally substituting the whole equation into equation (1), we get:

[0094]

[0095]

[0096] In the formula: The angle between the direction of the particle's vibration velocity and the slope surface line; Angular frequency; The phase is the state of motion of the vibrating object at the moment when timing begins (t=0). This is the decay exponent; the meanings of the other variables are the same as above.

[0097] To determine the angle between the direction of the particle's vibration velocity and the slope surface line. The relevant calculation model is shown in Figure 1. An x-o-y rectangular coordinate system is established along the slope. Suppose there is a particle on the slope layer, and the distance between the particle and the blast source is R. Assume that the direction of the vibration velocity of the particle is the extension of the line connecting the particle and the blast source. Then, by decomposing the vibration velocity of the particle along the slope and perpendicular to the slope, we can obtain the vibration velocity of the particle along the slope layer and the vibration velocity perpendicular to the slope layer.

[0098] Using the trigonometric function theorem, we have:

[0099]

[0100]

[0101] Finally, by substituting equation (7) into equation (6), the additional normal stress and additional shear stress generated by the weak interlayer of the slope under the action of underground blasting vibration load can be obtained, which lays the foundation for the later study on the stability analysis of the weak interlayer rock slope under the action of blasting vibration load.

[0102] To analyze and calculate the sliding dynamic stability of a weak interlayer slope under blasting vibration load, a relevant mechanical calculation model was established, such as... Figure 2 As shown.

[0103] For weak interlayered rock masses, the forces acting on them can be expressed as follows:

[0104]

[0105] In the formula: This refers to the normal pressure between the bedding rock mass and the parent rock mass. The length of the rock stratum.

[0106] like Figure 3 As shown, in order to analyze the cumulative damage to the rock mass caused by repeated blasting vibrations and the stability of the slope after damage, the degradation of the weak interlayer by blasting vibrations is simulated by continuously reducing the natural parameters of the weak interlayer. The stability of the slope under different reduction coefficients is analyzed, and the expression is:

[0107]

[0108]

[0109] Where: cohesion and internal friction angle These are the shear strength parameters of the soil and rock mass before weakening; , These are the weakened shear strength parameters; This is the reduction factor.

[0110] The sliding force of the landslide body on the slope is:

[0111]

[0112] In the formula:

[0113] ;

[0114] The anti-sliding force provided by the slope slip surface is:

[0115]

[0116] In the formula:

[0117] ;

[0118] According to the commonly used definition of the stability coefficient for slopes, the safety factor of the slope during slippage of weak interlayers is:

[0119]

[0120] Substituting equations (10) and (11) into equation (12) respectively, we can obtain the formula for calculating the safety factor of a soft interlayered rock slope under blasting vibration.

[0121] Figure 4 This is a schematic diagram of the Mohr-Coulomb strength envelope, used to illustrate the change in shear strength parameters of weak interlayers before and after blasting vibration, according to this embodiment. The diagram shows the original strength envelope of the rock mass before blasting, and the strength envelope after reduction considering the dynamic weakening effect (after blasting). Under the same normal stress conditions, the corresponding shear strength is significantly reduced after blasting, intuitively demonstrating the influence of strength parameter reduction on the anti-slip ability of the sliding surface.

[0122] Figure 5 This is a schematic geological profile of a rock slope containing weak interlayers according to this embodiment. The figure clearly shows the stratigraphic structure of the slope, including the weak interlayers (such as medium-argillaceous silty mudstone interbedded with sandstone) that serve as potential sliding surfaces, as well as the hanging wall and footwall rock masses (such as argillaceous siltstone and argillaceous conglomerate). This figure provides direct geological basis for determining the geometric parameters, rock mass physical and mechanical parameter zoning, and the location of potential sliding surfaces in the computational model.

[0123] To verify the effectiveness and engineering applicability of the method proposed in this embodiment, a typical weak interlayered rock slope next to the Yichang Expressway toll station was selected for case analysis:

[0124] Project overview and calculation parameters:

[0125] The slope is mainly composed of silty mudstone with a controlling weak interlayer that forms a potential sliding surface. The slope and blasting-related parameters are as follows:

[0126] Geometric parameters: Sliding surface inclination angle =23°, length along the sliding surface direction =110.9m. Distance from the blast point to the sliding center of gravity. =84.6m, the distance from the blast point to the outcrop of the sliding surface =93.9m, the longitudinal distance between the slip surface outcrop and the blasting point projected onto the slope. =24.3m.

[0127] Rock mass physical and mechanical parameters: rock elastic modulus =10 GPa, Poisson's ratio =0.20, natural severity =20kN / m³, density =2.04 g / cm³, rock mass integrity coefficient =0.65. Static shear strength parameter of weak interlayer: cohesion =100kPa, internal friction angle =21°.

[0128] Blasting load parameters: amount of explosives per blast =200kg, blasting vibration coefficient =100, decay index =1.4, vibration frequency =25Hz, initial phase =0. Intensity reduction factor considering dynamic weakening effect. =1.8.

[0129] Applying the method of this embodiment, the calculation and analysis are performed according to the following core steps:

[0130] Step 1: Refined Simulation of Blasting Vibration Effects

[0131] First, the peak vibration velocity of the rock mass particles on the slope is calculated according to equation (2). Furthermore, based on equation (3) and the given frequency, initial phase, and attenuation index, the vibration velocity time history v(t) is determined. Simultaneously, based on equations (4) and (5) and the rock mass parameters, the propagation velocities of longitudinal and transverse waves in the rock mass are calculated. Finally, the included angle determined by geometric relationship equation (7) is used... The time histories of dynamic normal stress and dynamic shear stress acting on the potential sliding surface are calculated by the core formula (6).

[0132] Step Two: Consideration of weakening the dynamics of the weak interlayer:

[0133] According to equation (9), the static strength parameters of the weak interlayer are reduced. The initial cohesion is... and internal friction angle The tangent value, divided by the reduction factor, is respectively =1.8, yielding the weakened cohesion used for dynamic stability analysis. and weakened internal friction angle .

[0134] Step 3: Integrated Computing and Security Assessment

[0135] The self-weight G of the sliding body and the peak dynamic stress obtained in step one are used to calculate the weight of the sliding body G and the peak dynamic stress obtained in step one. , ), and the weakening strength parameters obtained in step two ( , Substitute these into the limit equilibrium model (see equations (8), (10), and (11)). Based on the ratio of anti-sliding force to sliding force (equation (12)), calculate the safety factor of the slope under natural conditions (without blasting vibration) and under blasting vibration.

[0136] Calculation results and analysis:

[0137] Stability in natural state (unexploded): without considering blast loads and using static strength parameters ( , Under the condition that the slope safety factor K is calculated to be 1.74 > 1.0, it indicates that the slope is in a stable state.

[0138] Stability under blasting vibration: Considering the dynamic stress generated by blasting vibration acting on the sliding surface, and using weakened strength parameters ( , The calculation was performed. Under the extreme case (taking the peak dynamic stress), the slope safety factor K was calculated to be 0.76 < 1.0.

[0139] Calculation results show that under the blasting operation conditions, the safety factor of the slope containing the weak interlayer significantly decreased from 1.74 in the stable state to 0.76, indicating a sharp increase in the risk of slope instability. This result clearly reveals that blasting vibration exerts a significant combined deterioration effect on slope stability through two mechanisms: directly applying dynamic surface forces and weakening the strength of the weak interlayer. This example verifies that the method proposed in this embodiment can quantitatively and reasonably assess this complex process, and its calculation results have direct guiding significance for engineering safety early warning and protection decisions.

[0140] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for stability analysis of a weak interlayer slope under blasting vibration, characterized in that, Includes the following steps: The amount of explosives used in a single blast, the distance from the blast point to the center of gravity of the slope sliding mass, the blasting vibration coefficient and the attenuation index are obtained to determine the vibration velocity of the rock mass particles on the slope. The propagation velocity of stress waves in the rock mass is determined based on the rock's elastic modulus, Poisson's ratio, density, and rock mass integrity coefficient. Based on the vibration velocity, the propagation velocity of the stress wave in the rock mass, the rock mass density, and the angle between the particle vibration direction and the potential sliding surface, the dynamic normal stress and dynamic shear stress generated by the blasting vibration on the potential sliding surface as a function of time are calculated. Based on the initial cohesion, initial internal friction angle, and preset strength reduction coefficient of the weak interlayer, the weakened cohesion and weakened internal friction angle of the weak interlayer after blasting vibration are determined. The safety factor for evaluating slope stability is calculated based on the self-weight of the sliding body, dynamic normal stress, dynamic shear stress, weakened cohesion, and weakened internal friction angle.

2. The method according to claim 1, characterized in that, The vibration velocity of the rock mass particles on the slope is determined as follows: The peak vibration velocity of the rock mass particles on the slope is calculated based on the amount of explosive used in a single blast, the distance from the blast point to the center of gravity of the slope sliding mass, the blast vibration coefficient and the attenuation index. Based on the peak vibration velocity, and according to the law of sinusoidal periodic change and exponential decay over time described by the set vibration frequency, initial phase and decay index, the vibration velocity time history of the slope rock mass particles is determined.

3. The method according to claim 1, characterized in that, The dynamic normal stress and dynamic shear stress generated by blasting vibration on the potential sliding surface as a function of time are calculated as follows: The dynamic normal stress is generated by the action of longitudinal waves, and its instantaneous value is proportional to the rock mass density, the propagation speed of the longitudinal waves in the rock mass, and the component of the vibration velocity in the direction perpendicular to the potential sliding surface. The dynamic shear stress is generated by the action of transverse waves, and its instantaneous value is proportional to the rock mass density, the propagation speed of the transverse waves in the rock mass, and the component of the vibration velocity in the direction parallel to the potential sliding surface.

4. The method according to claim 1, characterized in that, Determining the angle between the direction of particle vibration and the potential sliding surface includes: Establish a plane coordinate system based on the slope; based on the location of the blasting source, the location of the mass point, and the geometric relationship of the sliding surface, calculate the angle between the vibration direction of the mass point and the potential sliding surface using trigonometric functions.

5. The method according to claim 1, characterized in that, The weakened cohesion and weakened internal friction angle of the weak interlayer after blasting vibration are determined as follows: Divide the initial cohesion by the strength reduction factor to obtain the weakened cohesion; Dividing the tangent of the initial internal friction angle by the strength reduction factor yields the tangent of the weakened internal friction angle.

6. The method according to claim 1, characterized in that, The safety factor used to evaluate slope stability is calculated, including: Calculate the sliding force of the sliding body, which is the sum of the component of the sliding body's own weight along the sliding surface and the contribution of the dynamic shear stress on the sliding surface; Calculate the anti-slip force of the sliding surface, wherein the anti-slip force is the product of the normal force of the sliding surface and the tangent of the weakened internal friction angle, plus the contribution of the weakened cohesion on the sliding surface; wherein the normal force of the sliding surface is the difference between the component of the sliding body's self-weight perpendicular to the sliding surface and the contribution of the dynamic normal stress on the sliding surface. The ratio of the anti-slip force to the sliding force is used as the safety factor.

7. The method according to claim 1 or 6, characterized in that, When calculating the safety factor, the dynamic normal stress and the dynamic shear stress are used at their peak values.

8. A computer device comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the method according to any one of claims 1-7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the method according to any one of claims 1-7.

10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the method according to any one of claims 1-7.

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