Method, system, equipment and medium for simulating dynamic response of water-bearing rock mass fractures

Abstract

This invention belongs to the field of rock mechanics technology and relates to a method, system, equipment, and medium for simulating the dynamic response of fractures in aquifers. It includes obtaining the initial thickness, initial porosity, and initial saturation of fractures in aquifers based on their physical properties, and obtaining compressive stress waves through experiments; obtaining the critical compressive displacement using the initial porosity, initial thickness, and initial saturation; and establishing a nonlinear-linear transformation constitutive model of fractures in aquifers under compressive stress waves using a discrete element method based on the critical compressive displacement and compressive stress waves. This constitutive model is then applied to the fractures in a geometric model of the aquifer to conduct simulation experiments, achieving simulation of the dynamic response of fractures in aquifers. This method overcomes the limitations of traditional single-factor analysis and significantly improves the prediction accuracy of the dynamic response of fractures in aquifers under different occurrence environments by quantifying the dynamic correlation between the critical compressive displacement and saturation and porosity.

Description

Technical Field

[0001] This invention belongs to the field of rock mechanics technology, specifically relating to methods, systems, equipment, and media for simulating the dynamic response of fractures in water-bearing rock masses. Background Technology

[0002] The dynamic response characteristics of rock masses are controlled by discontinuous fractures such as faults and joints. Among these, filled fractures, due to the presence of weathered residual clay and granular media such as quartz sand formed by tectonic shearing, become key weak areas in the dynamic stability of rock masses. These weak interfaces exhibit multi-field coupled mechanical behavior under compressive stress waves: when compressive stress waves induced by external loads such as earthquakes or explosions propagate to the fractures in water-bearing rock masses, the interfaces simultaneously bear the combined stresses of normal compression and tangential shearing, inducing granular particle slippage, rearrangement, and pore compaction. During this process, the energy of the compressive stress waves is dissipated through multiple paths, including particle frictional breakage, interface reflection, and P-wave to S-wave mode conversion, forming a significant "wave-particle" dynamic coupling effect.

[0003] The water content of fractures in aquifers profoundly affects their mechanical response by regulating the distribution of effective stress between particles and pore water pressure: in a dry state (0% saturation), interparticle contact friction dominates nonlinear hardening behavior; in a fully saturated state (100% saturation), pore water pressure restricts particle movement, resulting in linear transmission characteristics of compressive stress waves; while in a partially saturated state (0% < saturation < 100%), a dynamic transformation process between nonlinear compaction and linear bearing capacity is exhibited, reflecting the complex relationship between geological conditions and dynamic loading paths.

[0004] For example, Chinese patent application CN118428182A discloses a discontinuous calculation method and system for coupling pore-fracture seepage and deformation. This method includes constructing a numerical calculation model of pore seepage-fracture seepage-rock mass deformation, meshing the numerical calculation model to obtain an unstructured mesh element model, determining the fluid pressure at each seepage control node, calculating the fluid pressure at fracture nodes and the load caused by the fluid pressure at pore nodes, solving for the stress and deformation of the block elements, and updating the fracture geometry and the conductivity of each seepage channel. However, this method lacks the judgment of the water saturation and compressive stress wave amplitude of the rock mass when constructing the numerical calculation model, and does not consider the combined response of nonlinear compaction and linear bearing capacity of the rock mass, resulting in insufficient accuracy of the calculation.

[0005] Existing constitutive models have significant limitations in describing the dynamic behavior of fractures in aquifers. For dry conditions, low-amplitude compressive stress waves can be simplified to a linear elastic model, but high-amplitude loads require the introduction of a nonlinear model to characterize particle rearrangement and pore evolution. In fully saturated conditions, particle movement is inhibited by pore water pressure, making only linear elastic assumptions applicable. In partially saturated conditions, the combined response of nonlinear compaction and linear bearing capacity must be considered simultaneously. The main drawbacks of traditional models include:

[0006] 1) No dynamic response criterion for joint control of water saturation and compressive stress wave amplitude has been established;

[0007] 2) Lack of a unified framework to characterize the dynamic evolution of stiffness under water-particle interactions;

[0008] 3) The impact of pore water pressure on energy dissipation pathways has not yet been quantified;

[0009] Therefore, it is urgent to find a way to break through the aforementioned theoretical and technical bottlenecks. Summary of the Invention

[0010] To address the problems existing in the prior art, this invention provides a method, system, equipment, and medium for simulating the dynamic response of fractures in water-bearing rock masses. It establishes a dynamic response criterion jointly controlled by water saturation and compressive stress waves, significantly improving the predictive ability of dynamic response of fractures in water-bearing rock masses and providing a theoretical basis for assessing the dynamic stability of rock mass engineering.

[0011] This invention is achieved through the following technical solution:

[0012] In a first aspect, the present invention provides a method for simulating the dynamic response of fractures in water-bearing rock masses, including,

[0013] Based on the physical properties of the aquifer, the initial thickness, initial porosity, and initial saturation of the fractures in the aquifer were measured; Hopkinson bar tests were conducted on the fractures in the aquifer to obtain compressive stress waves.

[0014] The critical compressibility displacement of the fractures in the water-bearing rock mass was calculated using the initial porosity, initial thickness, and initial saturation.

[0015] Based on the critical compressive displacement and compressive stress wave, a nonlinear-linear transformation constitutive model of water-bearing rock mass fractures under the action of compressive stress wave is established using the discrete element method.

[0016] Based on the geometric dimensions of the water-bearing rock mass, as well as the dip angle and location parameters of the fractures in the water-bearing rock mass, a geometric model of the water-bearing rock mass is established, and boundary conditions are set for the geometric model of the water-bearing rock mass.

[0017] The nonlinear-linear transformation deformation constitutive model of water-bearing rock mass fractures under compressive stress wave action was applied to the water-bearing rock mass fractures in the geometric model of water-bearing rock mass to conduct simulation experiments, thereby realizing the simulation of the dynamic response of water-bearing rock mass fractures.

[0018] Preferably, based on the physical properties of the aquifer, the initial thickness, initial porosity, and initial saturation of the fractures in the aquifer are measured, specifically:

[0019] Based on the physical properties of aquifers, quartz sand and water were used as filling materials for the fissures in the aquifers. By controlling the mass ratio, a physical model of the aquifers was built. Based on the physical model of the aquifers, the initial thickness, initial porosity, and initial saturation of the fissures in the aquifers were measured.

[0020] Hopkinson bar tests were conducted on fractures in water-bearing rock masses to obtain compressive stress waves, specifically:

[0021] Impact tests were conducted on the fractures of the water-bearing rock mass using the Hopkinson pressure bar device to obtain the compressive stress waves acting on the fractures of the water-bearing rock mass.

[0022] The compressive stress wave includes incident waves of different amplitudes from the fissures in the water-bearing rock mass, as well as compressive transmitted waves that pass through the fissures in the water-bearing rock mass.

[0023] Preferably, the mathematical expression for the critical compressive displacement is:

[0024]

[0025] In the formula: This is the critical compressive displacement when the fissures in the water-bearing rock mass reach saturation. s , δ and h These represent the initial saturation, initial porosity, and initial thickness of the fractures in the water-bearing rock mass, respectively.

[0026] Preferably, a nonlinear-linear transformation constitutive model for the deformation of fractures in a water-bearing rock mass under compressive stress waves is established, specifically as follows:

[0027] Using the discrete element method, based on the critical compressive displacement and compressive stress wave, the compressive stress-closure relationship of the fractures in the water-bearing rock mass is set as a nonlinear-linear transformation relationship. In the nonlinear segment, an exponential function is used to simulate the rearrangement and compaction process of the filling particles in the fractures of the water-bearing rock mass. After exceeding the critical compressive displacement, it is converted into a linear function to characterize the stiffness change dominated by pore water pressure after the fractures of the water-bearing rock mass are saturated with water. Thus, a nonlinear-linear transformation deformation constitutive model of the fractures in the water-bearing rock mass under the action of compressive stress wave is established.

[0028] Preferably, the mathematical expression for the nonlinear-linear transformation deformation constitutive model of fractures in a water-bearing rock mass under compressive stress wave action is:

[0029] Under compression:

[0030] ;

[0031] In the formula: The part is a non-linear segment. The portion is a linear segment;

[0032] Under shearing conditions:

[0033] ;

[0034] In the formula, σ n and u n These represent the compressive stress and compressive displacement of the fractures in the water-bearing rock mass, respectively. u f and σ f These represent the critical compressive displacement and normal compressive stress when the fractures in the water-bearing rock mass reach saturation, respectively. τ and u s These represent the shear stress and shear displacement of the fractures in the water-bearing rock mass, respectively. a 1 represents the first fitting coefficient of the nonlinear segment. a 2 represents the second fitting coefficient for the nonlinear segment. a 3 represents the compressive stiffness enhancement factor for the transition from nonlinear to linear; a 4 represents the shear stiffness of the fractures in the water-bearing rock mass; τ 0 and φ These represent the shear strength and friction angle of the fracture in the water-bearing rock mass, respectively.

[0035] Preferably, boundary conditions are set for the geometric model of the water-bearing rock mass, specifically as follows:

[0036] Absorbing boundaries are set on both sides of the geometric model of the water-bearing rock mass to prevent the compressive stress waves propagating and reflecting to the boundary of the geometric model of the water-bearing rock mass from being reflected.

[0037] Preferably, the nonlinear-linear transformation deformation constitutive model of water-bearing rock mass fractures under compressive stress wave action is applied to the water-bearing rock mass fractures in the geometric model of the water-bearing rock mass to conduct simulation experiments, thereby realizing the simulation of the dynamic response of water-bearing rock mass fractures. Specifically:

[0038] A nonlinear-linear transformation constitutive model of fractures in aquifers under compressive stress waves was applied to the fractures within the geometric model of the aquifer. Simulation experiments were conducted, calculating the critical compressive displacement given the initial thickness, porosity, and saturation of the fractures. During the calculation of compressive stress wave propagation, the compressive displacement of the current fractures in the aquifer was returned in real time. u n and through the critical compressive displacement u f By comparing the results, it is determined whether the current segment is nonlinear or linear. Through the piecewise response of nonlinear exponential hardening and linear bearing, the dynamic response of fractures in water-bearing rock masses is simulated.

[0039] Secondly, this invention provides a simulation system for the dynamic response of fractures in water-bearing rock masses, comprising,

[0040] The parameter acquisition module measures the initial thickness, initial porosity, and initial saturation of the fractures in the aquifer based on the physical properties of the aquifer. Hopkinson bar tests are then conducted on the fractures in the aquifer to obtain compressive stress waves.

[0041] The critical compressibility displacement acquisition module calculates the critical compressibility displacement of the fractures in the water-bearing rock mass using the initial porosity, initial thickness, and initial saturation.

[0042] The constitutive model building module is used to establish a nonlinear-linear transformation deformation constitutive model of water-bearing rock mass fractures under the action of compressive stress waves based on critical compressive displacement and compressive stress waves, using the discrete element algorithm.

[0043] The geometric model building module is used to build a geometric model of the water-bearing rock mass and set boundary conditions based on the geometric dimensions of the water-bearing rock mass and the dip angle and location parameters of the fractures in the water-bearing rock mass.

[0044] The dynamic response simulation module is used to apply the nonlinear-linear transformation deformation constitutive model of water-bearing rock fractures under compressive stress wave action to the water-bearing rock fractures in the geometric model of water-bearing rock mass, and to conduct simulation experiments to realize the dynamic response simulation of water-bearing rock fractures.

[0045] Thirdly, the present invention provides a computer device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method for simulating the dynamic response of fractures in a water-bearing rock mass as described in the claims.

[0046] Fourthly, the present invention provides a computer-readable storage medium storing a computer program, characterized in that, when the computer program is executed by a processor, it implements the steps of the method for simulating the dynamic response of fractures in a water-bearing rock mass.

[0047] Compared with the prior art, the present invention has the following beneficial technical effects:

[0048] This invention provides a method for simulating the dynamic response of fractures in aquifers. Targeting the physical characteristics of fractures in aquifers and considering parameters such as initial thickness, initial porosity, and initial saturation, it proposes for the first time a method for calculating the critical compressive displacement. Using compressive stress wave data obtained from Hopkinson bar experiments, a nonlinear-linear transformation constitutive model of fractures in aquifers under compressive stress waves is constructed, and numerical simulation is achieved using the discrete element method. This nonlinear-linear transformation constitutive model of fractures in aquifers under compressive stress waves comprehensively considers the influence of different initial saturation, initial thickness, and initial porosity on the deformation characteristics of fractures in aquifers, effectively overcoming the shortcomings of traditional models that neglect fluid interaction and cannot consider the nonlinear-linear dynamic transformation process. By setting the geometric model of the aquifer, the dip angle and location parameters of the fractures, and combining boundary conditions, this invention realistically recreates the dynamic response process of fractures in aquifers under complex working conditions. The established nonlinear-linear transformation constitutive model can not only accurately characterize the wave propagation characteristics of cracks under compressive stress waves under different saturation conditions, but also improve the reliability and applicability of dynamic response simulation through the dual-parameter response criterion of critical compressive displacement and compressive stress wave amplitude.

[0049] Furthermore, by using the piecewise response of nonlinear exponential hardening and linear bearing, the energy dissipation paths such as the rearrangement, compaction process, and P / S wave mode conversion of the filling particles in the fissures of water-bearing rock masses are quantified. Combined with the critical compression displacement criterion, the wave-particle coupling effect in the propagation of compressive stress waves is accurately reflected, providing a multidimensional theoretical basis for the assessment of rock mass dynamic stability.

[0050] Furthermore, this invention proposes a critical compressive displacement. u f =(1- s ) δh The calculation method involves determining the initial saturation of fractures in the water-bearing rock mass. s Initial porosity δ and initial thickness h The critical compressive displacement corresponding to the transition from unsaturation to saturation of water-filled fractures was calculated and used as the stiffness abrupt change threshold. Based on this, relevant parameters of the stiffness abrupt change threshold, namely the first fitting coefficient of the nonlinear segment, were constructed. a 1. Second fitting coefficient of the nonlinear segment a2. Compression stiffness enhancement coefficient during nonlinear to linear transformation a The adjustment rules of 3, for the first time, quantify the nonlinear control mechanism of pore water pressure on the evolution of fracture stiffness in water-bearing rock masses, and solve the problem that traditional models cannot describe the jump change in stiffness before and after water saturation.

[0051] Furthermore, this invention automatically determines whether the fracture deformation is in a nonlinear or linear segment by returning the current fracture compression displacement in real time and dynamically comparing it with the critical compression displacement. It is also the first to combine the nonlinear-linear transformation deformation constitutive model of water-bearing rock fractures under the action of compressive stress waves with the discrete element algorithm, which overcomes the limitation of traditional models that cannot characterize the sudden change in stiffness caused by the change in saturation of water-filled fractures during the deformation stage, and improves the engineering applicability of simulation of complex geological conditions. Attached Figure Description

[0052] Figure 1 Flowchart of the simulation method for dynamic response of fractures in water-bearing rock masses;

[0053] Figure 2 The diagram shows the nonlinear-linear transformation deformation results of fractures in aquatic rock mass; where (a) is the nonlinear-linear transformation deformation curve of fractures in aquatic rock mass under compression; and (b) is the deformation curve of fractures in aquatic rock mass under shear.

[0054] Figure 3 The computational logic diagram for simulating the dynamic response of fractures in water-bearing rock masses;

[0055] Figure 4 This is a UDEC numerical model of the nonlinear-linear response of a single water-bearing rock mass fracture to compressive stress waves; where UDEC is an abbreviation for Universal Distinct Element Code, a software used to simulate the mechanical behavior of discontinuous media, commonly used in rock engineering for the analysis of fractures, faults, etc.

[0056] Figure 5 The results are from UDEC simulations of the response of a single water-bearing rock mass fracture to low-amplitude compressive stress waves.

[0057] Figure 6 The results are from UDEC simulations of the response of a single water-bearing rock mass fracture to high-amplitude compressive stress waves.

[0058] Figure 7 The results of UDEC simulations show the variations in reflection and transmission coefficients of compressive stress waves of different amplitudes passing through a single water-bearing rock mass fracture. Detailed Implementation

[0059] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0060] Example 1

[0061] Methods for simulating the dynamic response of fractures in water-bearing rock masses, such as Figure 1 As shown, including,

[0062] S1. Based on the physical properties of the water-bearing rock mass, the initial thickness, initial porosity, and initial saturation of the fractures in the water-bearing rock mass were measured; the Hopkinson bar test was conducted on the fractures in the water-bearing rock mass to obtain the compressive stress wave.

[0063] S2, using initial porosity, initial thickness and initial saturation, calculates the critical compressive displacement of the fractures in the water-bearing rock mass.

[0064] S3. Based on critical compressive displacement and compressive stress wave, a nonlinear-linear transformation constitutive model of water-bearing rock mass fractures under the action of compressive stress wave is established using the discrete element method.

[0065] S4. Based on the geometric dimensions of the water-bearing rock mass, as well as the dip angle and location parameters of the fractures in the water-bearing rock mass, a geometric model of the water-bearing rock mass is established, and the boundary conditions of the geometric model of the water-bearing rock mass are set.

[0066] S5 applies the nonlinear-linear transformation deformation constitutive model of water-bearing rock mass fractures under compressive stress wave action to the water-bearing rock mass fractures in the geometric model of water-bearing rock mass, and conducts simulation experiments to realize the simulation of the dynamic response of water-bearing rock mass fractures.

[0067] This invention proposes a nonlinear-linear transformation constitutive model for fractures in water-bearing rock masses under the action of compressive stress waves, and realizes numericalization based on the general discrete element algorithm. It accurately characterizes the wave propagation characteristics of critical compressive displacement and compressive stress waves in fractures of water-bearing rock masses with different saturation levels, establishes a two-parameter response characterization method for water-bearing state and compressive stress wave amplitude, and proposes a dynamic stiffness evolution equation considering abrupt changes in pore water pressure.

[0068] Based on the physical properties of aquifers, indoor simulation experiments were conducted. Quartz sand and water were used as filling materials for the fractures in the aquifers. Through mass ratio control, fractures in the aquifers were artificially prepared, and the initial porosity was measured. δ Initial thickness h and initial saturation sSubsequently, an impact test was conducted on the fractures of the water-bearing rock mass using a Hopkinson pressure bar device to obtain the compressive stress wave acting on the fractures of the water-bearing rock mass;

[0069] The compressive stress waves include incident waves of different amplitudes from the fissures in the aquifer, as well as compressive transmitted waves that pass through the fissures, providing verification data for subsequent nonlinear-linear response simulations of the fissures in the aquifer.

[0070] The critical compressibility displacement of the fractures in the water-bearing rock mass was calculated using the initial porosity, initial thickness, and initial saturation.

[0071] The mathematical expression for the critical compressive displacement is:

[0072] (1)

[0073] In the formula: This is the critical compressive displacement when the fissures in the water-bearing rock mass reach saturation. s , δ and h These represent the initial saturation, initial porosity, and initial thickness of the fractures in the water-bearing rock mass, respectively.

[0074] This invention establishes a nonlinear-linear transformation constitutive model for fractures in water-bearing rock masses under compressive stress waves, specifically as follows:

[0075] Using the discrete element method, based on the critical compressive displacement and compressive stress wave, the compressive stress-closure relationship of the fractures in the water-bearing rock mass is set as a nonlinear-linear transformation relationship. In the nonlinear segment, an exponential function is used to simulate the rearrangement and compaction process of the filling particles in the fractures of the water-bearing rock mass. After exceeding the critical compressive displacement, it is converted into a linear function to characterize the stiffness change dominated by pore water pressure after the fractures of the water-bearing rock mass are saturated with water. Thus, a nonlinear-linear transformation deformation constitutive model of the fractures in the water-bearing rock mass under the action of compressive stress wave is established.

[0076] Figure 2 The diagram shows the nonlinear-linear transformation deformation results of fractures in aquifers. Under compression, the constitutive model of nonlinear-linear transformation deformation of fractures in aquifers under compressive stress waves allows a certain amount of overlap between two rock blocks, which is regarded as the closure amount of fractures in aquifers.

[0077] Throughout the compression process, the nonlinear-linear deformation of the fractures in the water-bearing rock mass is characterized by a piecewise function. The threshold of the function is defined by the coupling relationship between saturation and compression displacement. Under shear action, linear deformation occurs first, and slip deformation occurs when the shear strength is exceeded.

[0078] The nonlinear-linear transformation deformation constitutive model of water-bearing rock mass fractures under compressive stress wave action specifically refers to the relationship between normal compressive stress and normal displacement, as well as the relationship between shear stress and shear displacement, of water-bearing rock mass fractures under compressive stress wave action. The relationship between normal compressive stress and normal displacement needs to be determined by the critical compressive displacement to determine the stage.

[0079] The mathematical expression for the nonlinear-linear transformation deformation constitutive model of fractures in a water-bearing rock mass under compressive stress wave action is as follows:

[0080] Under compression:

[0081] (2)

[0082] In the formula: The part is a non-linear segment. The portion is a linear segment;

[0083] Under shearing conditions:

[0084] (3)

[0085] In the formula, σ n and u n These represent the compressive stress and compressive displacement of the fractures in the water-bearing rock mass, respectively. u f and σ f These represent the critical compressive displacement and normal compressive stress when the fractures in the water-bearing rock mass reach saturation, respectively. τ and u s These represent the shear stress and shear displacement of the fractures in the water-bearing rock mass, respectively. a 1 represents the first fitting coefficient of the nonlinear segment; a 2 represents the second fitting coefficient for the nonlinear segment; a 3 represents the compressive stiffness enhancement factor for the transition from nonlinear to linear; a 4 represents the shear stiffness of the fractures in the water-bearing rock mass; τ 0 and φ These represent the shear strength and friction angle of the fracture in the water-bearing rock mass, respectively.

[0086] Based on the geometric dimensions of the aquifer, as well as the dip angle and location parameters of the fractures in the aquifer, a geometric model of the aquifer is established and boundary conditions are set, specifically as follows:

[0087] Based on the geometric dimensions of the aquifer, as well as the dip angle and location parameters of the fissures in the aquifer, a geometric model of the aquifer is established. Its geometric dimensions are consistent with those of the aquifer in the indoor simulation test. The contact between two rock blocks is used to represent the fissures in the aquifer.

[0088] Figure 3 This is the computational logic diagram of the dynamic response simulation method for fractures in aquifers described in this invention. The nonlinear-linear transformation constitutive model of fractures in aquifers under compressive stress waves is applied to the fractures in the geometric model of the aquifer, and simulation experiments are conducted. Given the initial thickness, initial porosity, and initial saturation of the fractures, the critical compressive displacement is calculated. During the calculation of compressive stress wave propagation, the compressive displacement of the current fracture in the aquifer is returned in real time. u n and through the critical compressive displacement u f By comparing the current state with that of a nonlinear or linear segment, and using the piecewise responses of nonlinear exponential hardening and linear bearing capacity, the dynamic response of fractures in water-bearing rock masses is simulated. Specifically:

[0089] The incident waves of different amplitudes from the water-bearing rock mass fractures recorded in the experiment were used as the dynamic load input in the numerical simulation. By adjusting the parameters in formulas (2) and (3), i.e. the first fitting coefficient of the nonlinear segment, a 1. Second fitting coefficient of the nonlinear segment a 2. Compression stiffness enhancement coefficient during nonlinear to linear transformation a 3. Shear stiffness of fractures in water-bearing rock masses a 4. By altering the waveform of the compression transmission wave output after passing through the fractures in the water-bearing rock mass, when a set of parameters is adjusted so that the simulated compression transmission wave waveform coincides with the experimentally recorded compression transmission wave, the first fitting coefficient of the nonlinear segment at this point is considered to be... a 1. Second fitting coefficient of the nonlinear segment a 2. Compression stiffness enhancement coefficient during nonlinear to linear transformation a 3. Shear stiffness of fractures in water-bearing rock masses a 4. Capable of characterizing initial porosity δ Initial thickness h and initial saturation s The compression and shear deformation stiffness parameters of the fractures in the water-bearing rock mass are determined. This process, known as experimental result calibration, verifies the feasibility and accuracy of the established geometric model of the water-bearing rock mass.

[0090] The first fitting coefficient of the nonlinear segment obtained a 1. Second fitting coefficient of the nonlinear segment a 2. Compression stiffness enhancement coefficient during nonlinear to linear transformation a 3. Shear stiffness of fractures in water-bearing rock masses a 4. Initial porosity δ initial thickness h and initial saturation sCompression and shear deformation stiffness parameters of fractures in water-bearing rock masses, simulating initial porosity δ The initial thickness is h and initial saturation s The dynamic response of water-bearing rock fractures to compressive stress waves under other complex working conditions (complex working conditions refer to working conditions that cannot be realized in the laboratory) is studied in order to accurately characterize the wave propagation characteristics of compressive stress waves in water-bearing rock fractures with different saturation levels.

[0091] Then, based on obtaining the first fitting coefficient of the nonlinear segment... a 1. Second fitting coefficient of the nonlinear segment a 2. Compression stiffness enhancement coefficient during nonlinear to linear transformation a 3. Shear stiffness of fractures in water-bearing rock masses a 4. Initial porosity δ initial thickness h and initial saturation s The parameters of the fractures in the water-bearing rock mass are obtained. The nonlinear-linear transformation deformation constitutive model of the fractures in the water-bearing rock mass under the action of compressive stress wave is used to numerically simulate the propagation of compressive stress wave, so as to realize the simulation of the dynamic response of the fractures in the water-bearing rock mass.

[0092] Example 2

[0093] (1) Establish a geometric model of the aquifer: including the dimensions of the aquifer geometric model, the location, number, and occurrence of fractures in the aquifer; and attach... Figure 4 For example, two rock rods with a length of 2.5m and a diameter of 0.25m represent the geometric model of the water-bearing rock mass. The two rock rods are arranged side by side, and the contact point in the middle represents the fracture in the water-bearing rock mass. There is one fracture, with a length of 0.25m and a dip angle of 90°.

[0094] (2) Boundary condition settings: as shown in the attached document Figure 4 As shown, the left and right ends of the aquifer geometric model are both set as absorbing boundaries, i.e., the input and arrival ends of the compressive stress wave. The absorbing boundary ensures that the compressive stress wave propagating to the boundary of the aquifer geometric model is not reflected. In other words, whatever the stress propagating to the boundary, an equal and opposite stress will be automatically applied to counteract the stress on the boundary. Therefore, when inputting on the left side, a value of 2 should be used. σ enter.

[0095] (3) Setting model parameters: The water-bearing rock mass material adopts the classical elastic model, which involves rock mass modulus, Poisson's ratio, etc. The water-bearing rock mass fracture adopts the nonlinear-linear transformation deformation constitutive model of water-bearing rock mass fracture under the action of compressive stress wave, which involves the first fitting coefficient of the nonlinear segment. a 1. Second fitting coefficient of the nonlinear segment a2. Compression stiffness enhancement coefficient during nonlinear to linear transformation a 3. Shear stiffness of fractures in water-bearing rock masses a 4. Angle of friction φ, initial porosity δ initial thickness h and initial saturation s The parameters of fractures in the water-bearing rock mass; the basic physical and mechanical properties of the rock mass material can be obtained by consulting literature and conducting laboratory tests, including the initial porosity. δ initial thickness h and initial saturation s Same as the experimental setup, the first fitting coefficient of the nonlinear segment a 1. Second fitting coefficient of the nonlinear segment a 2. Compression stiffness enhancement coefficient during nonlinear to linear transformation a 3. Shear stiffness of fractures in water-bearing rock masses a 4. Set the parameters according to the calibration.

[0096] (4) Calculate the critical compressibility displacement of the fracture in the water-bearing rock mass according to formula (1). When performing calculations, the initial porosity δ initial thickness h and initial saturation s As with the experimental setup, the critical compressive displacement is fixed for water-bearing rock fractures with the same initial thickness, initial saturation, and initial void ratio of the filling material.

[0097] (5) Input compressive stress wave, such as Figure 5 As shown, taking a half-cycle sinusoidal compressive stress wave as an example, the expression for its particle vibration velocity is: ,in A For amplitude, f For frequency, t For time. Actual compressive stress. ,in The wave impedance of the rock mass medium. , ρ For rock mass density, The propagation velocity of P-waves in rock mass can be obtained experimentally. During the calculation process, in... Within the range, the normal compressive stress in the fractures of the water-bearing rock mass is induced by discontinuous compressive deformation. u n The nonlinear part of formula (2) is used for iterative calculation. By setting monitoring points on both sides of the cracks in the water-bearing rock mass in the geometric model of the water-bearing rock mass, the vibration velocity (or compressive stress) of the particles can be recorded, and the transmitted wave, reflected wave and incident wave can be obtained at the same time.

[0098] (6) When At times, such as Figure 6 As shown, the normal compressive stress in the fractures of the water-bearing rock mass is induced by discontinuous compressive deformation. u n The linear part of formula (2) is iteratively calculated. Similarly, by setting monitoring points on both sides of the fracture in the water-bearing rock mass geometric model, the vibration velocity (or compressive stress) of the particles can be recorded. At the same time, the transmitted wave, reflected wave and incident wave can be obtained.

[0099] (7) Steps (1)-(6) describe the case where the compressive stress wave is incident perpendicularly (i.e., when the angle between the incident direction and the crack normal is 0), such as Figure 7 As shown, when the compressive stress wave is obliquely incident, due to the decomposition of the compressive stress on the fracture, the fracture of the water-bearing rock mass may undergo sliding deformation, according to formula (3) before sliding. Partial calculation of shear deformation, after slippage is generated, is performed using formula (3). Partial shear stress and shear deformation are equal to the relative displacement of the block, and the block's motion is controlled by Newton's second law of motion. As the dynamic load is transmitted in real time, the above judgment conditions are continuously updated, and the stress magnitude of the water-bearing rock mass fissures is returned for judgment. The calculation stops after a preset calculation time and the results are output. The output results refer to the calculation process of the nonlinear-linear transformation deformation constitutive model of water-bearing rock mass fissures under compressive stress waves within given conditions and a specified time. During the calculation, physical quantities such as stress, displacement, and velocity are updated in real time. The result file only contains the final state. Users can set monitoring points to record process quantities, such as the change of the velocity field over time, according to their needs.

[0100] The critical compressibility displacement is used to distinguish whether the fractures in a water-bearing rock mass are in a fully saturated state during compression; the specific process for determining the critical compressibility displacement is as follows:

[0101] Compression of dry-filled fractured rock mass in water-bearing mass: For dry fractured rock mass with saturation of 0, assuming an initial porosity of 0.2 and an initial thickness of 5.0 mm, calculate the critical compressive displacement. u f=1.0mm. Before compression, the dry-filled fissures of the water-bearing rock mass are not subjected to external forces. At this time, the initial thickness of the fissures in the water-bearing rock mass is 5.0mm, and the initial porosity is 0.2. When compression begins, the filling material (granular material, such as quartz sand, clay, etc.) in the fissures of the water-bearing rock mass is gradually compacted, and the air is gradually expelled. During this process, the fissures in the water-bearing rock mass gradually close, the thickness decreases, and the porosity gradually decreases (gas is expelled). During the compression process, the porosity of the fissures in the water-bearing rock mass will only approach 0 infinitely, and the amount of thickness reduction (closure amount) will only approach 1.0mm infinitely. Therefore, the displacement generated during the compression process of the dry water-bearing rock mass fissures will not be greater than the critical compression displacement. Therefore, the relationship between the normal critical compression displacement and the normal compression stress of the water-bearing rock mass fissures can be expressed by formula (2) where 0 < u < u f The nonlinear part is represented.

[0102] Compression of fractures in unsaturated water-filled rock mass: For fractures in unsaturated water-filled rock mass, the saturation degree is greater than 0 and less than 1. Taking a saturation degree of 0.2 as an example, the initial porosity is 0.2 and the initial thickness is 5.0 mm. The critical compression displacement can be calculated according to formula (1). u f =0.8mm. After compression begins, the fracture gradually closes. As the closure amount u increases from 0 to 0.8mm, the relationship between the normal compressive stress and the critical compressive displacement of the fracture in the water-bearing rock mass can be expressed by formula (2), where 0 < u < u f The nonlinear part is represented as follows: When the closure amount increases to 0.8 mm, the air in the unsaturated water-bearing rock mass fractures is completely expelled, leaving only granular filling material and water. At this point, the water-bearing rock mass fractures are completely saturated, and water is almost incompressible. Therefore, the instantaneous transition from unsaturated to saturated state in the water-bearing rock mass fractures leads to a sudden increase in normal compressive stiffness. The corresponding normal compressive stress at this time is denoted as... σ f If we consider the fractures in the saturated water-bearing rock mass at this point as a relatively stiff whole, the sudden increase in stiffness also means that the compressibility of the fractures in the water-bearing rock mass has been greatly reduced. Under compression, even a small displacement can cause a large increase in compressive stress.

[0103] Compression of fully saturated water-bearing rock mass fractures: For fully saturated water-bearing rock mass fractures with a saturation degree of 1, assuming an initial porosity of 0.2 and an initial thickness of 5.0 mm, the critical compressive displacement can be calculated according to formula (1). u f =0. Therefore, for fractures in a fully saturated water-bearing rock mass, as long as it experiences external compressive stress and displacement, the calculation method for compressive stress and displacement will follow the formula (2). u >u f The linear part is calculated.

[0104] It should be noted that the stiffness of water-bearing rock masses increases abruptly after the fractures reach saturation during compression. Figure 2 The linear loading curve shown lies between the tangent and the perpendicular at the critical point.

[0105] This invention establishes for the first time a nonlinear-linear dynamic conversion criterion for the joint control of water saturation and compressive stress wave amplitude. Given the initial thickness of fractures, initial porosity, and initial saturation of the water-bearing rock mass, the critical compressive displacement is first calculated. Subsequently, during the calculation of compressive stress wave propagation, the current displacement is returned in real time. u n and through with u f By comparing the results, it can be determined whether the current loading stage is nonlinear or linear. Breaking through the limitations of the traditional single-factor analysis model, the dynamic correlation between critical compressibility displacement and saturation and porosity is quantified through formula (1), which significantly improves the prediction accuracy of the dynamic response of fractures in water-bearing rock masses under different occurrence environments.

[0106] A nonlinear-linear transformation constitutive model for fractures in aquifers under compressive stress waves is proposed. This model integrates the dynamic stiffness equations to account for abrupt changes in pore water pressure, enabling continuous characterization across dry, partially saturated, and fully saturated states. This effectively addresses the shortcomings of traditional models in characterizing abrupt stiffness changes and water-particle interactions. Through piecewise responses to nonlinear exponential hardening and linear bearing, the model quantifies energy dissipation paths such as the rearrangement of infill particles, compaction processes, and P / S wave mode transitions. Combined with shear slip criteria, this model accurately reflects the wave-particle coupling effect during compressive stress wave propagation, providing a multidimensional theoretical basis for assessing the dynamic stability of rock masses.

[0107] Based on the dual-parameter control of critical compressive displacement and compressive stress wave amplitude, a nonlinear-linear transformation constitutive model of fractures in water-bearing rock masses under the action of compressive stress waves is established. The nonlinear segment uses an exponential function to simulate the rearrangement and compaction process of the internally filled granular material, while the linear segment characterizes the stiffness abrupt change dominated by pore water pressure after saturation. Dynamic transformation is achieved through the critical compressive displacement criterion. This model overcomes the limitations of traditional single elastic or nonlinear models, and for the first time realizes piecewise modeling of the constitutive response under the coupled action of water-bearing state and compressive stress wave intensity.

[0108] This invention proposes a critical compressive displacement. u f =(1- s ) δh The calculation method involves determining the initial saturation of fractures in the water-bearing rock mass. s Initial porosity δand initial thickness h The critical compressive displacement corresponding to the transition from unsaturation to saturation of water-filled fractures was calculated and used as the stiffness abrupt change threshold. Based on this, relevant parameters of the stiffness abrupt change threshold, namely the first fitting coefficient of the nonlinear segment, were constructed. a 1. Second fitting coefficient of the nonlinear segment a 2. Compression stiffness enhancement coefficient during nonlinear to linear transformation a The adjustment rules in section 3, for the first time, quantify the nonlinear control mechanism of pore water pressure on the evolution of fracture stiffness in water-bearing rock masses, solving the problem that traditional models cannot describe the abrupt changes in stiffness before and after saturation. A joint control criterion of "saturation degree-compressible displacement" is defined, using the critical compressible displacement... u f The dynamic calculation enables automatic switching between nonlinear compaction and linear bearing capacity, and is based on the real-time judgment logic of the nonlinear-linear transformation deformation constitutive model of water-bearing rock fractures under compressive stress waves (such as...). Figure 3 As shown in the figure, a dynamic response rule under the synergistic effect of multiple factors is established to fill the theoretical gap of traditional models that lack composite criteria.

[0109] In another embodiment of the present invention, a computer device is provided, comprising a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions to achieve a corresponding method flow or corresponding function. The processor described in this embodiment of the present invention can be used for the operation of a simulation method for the dynamic response of fractures in water-bearing rock masses.

[0110] In another embodiment of the present invention, a storage medium is provided, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, the storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the simulation method for the dynamic response of fractures in water-bearing rock masses in the above embodiments.

[0111] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0112] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0113] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0114] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0115] 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 it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for simulating the dynamic response of fractures in water-bearing rock masses, characterized in that, include, Based on the physical properties of the water-bearing rock mass, the initial thickness, initial porosity, and initial saturation of the fractures in the water-bearing rock mass were measured. Hopkinson bar tests were conducted on fractures in water-bearing rock masses to obtain compressive stress waves. The critical compressibility displacement of the fractures in the water-bearing rock mass was calculated using the initial porosity, initial thickness, and initial saturation. Based on the critical compressive displacement and compressive stress wave, a nonlinear-linear transformation constitutive model of water-bearing rock mass fractures under the action of compressive stress wave is established using the discrete element method. Based on the geometric dimensions of the water-bearing rock mass, as well as the dip angle and location parameters of the fractures in the water-bearing rock mass, a geometric model of the water-bearing rock mass is established, and boundary conditions are set for the geometric model of the water-bearing rock mass. The nonlinear-linear transformation deformation constitutive model of water-bearing rock mass fractures under compressive stress wave action was applied to the water-bearing rock mass fractures in the geometric model of water-bearing rock mass to conduct simulation experiments, thereby realizing the simulation of the dynamic response of water-bearing rock mass fractures.

2. The method for simulating the dynamic response of fractures in water-bearing rock masses according to claim 1, characterized in that, Based on the physical properties of the aquifer, the initial thickness, initial porosity, and initial saturation of the fractures in the aquifer were measured, specifically: Based on the physical properties of aquifers, quartz sand and water were used as filling materials for the fissures in the aquifers. By controlling the mass ratio, a physical model of the aquifers was built. Based on the physical model of the aquifers, the initial thickness, initial porosity, and initial saturation of the fissures in the aquifers were measured. Hopkinson bar tests were conducted on fractures in water-bearing rock masses to obtain compressive stress waves, specifically: Impact tests were conducted on the fractures of the water-bearing rock mass using the Hopkinson pressure bar device to obtain the compressive stress waves acting on the fractures of the water-bearing rock mass. The compressive stress wave includes incident waves of different amplitudes from the fissures in the water-bearing rock mass, as well as compressive transmitted waves that pass through the fissures in the water-bearing rock mass.

3. The method for simulating the dynamic response of fractures in water-bearing rock masses according to claim 1, characterized in that, The mathematical expression for the critical compressive displacement is: In the formula: This is the critical compressive displacement when the fissures in the water-bearing rock mass reach saturation. s , δ and h These represent the initial saturation, initial porosity, and initial thickness of the fractures in the water-bearing rock mass, respectively.

4. The method for simulating the dynamic response of fractures in water-bearing rock masses according to claim 1, characterized in that, A nonlinear-linear transformation constitutive model for fractures in aquatic rock masses under compressive stress waves is established, specifically as follows: Using the discrete element method, based on the critical compressive displacement and compressive stress wave, the compressive stress-closure relationship of the fractures in the water-bearing rock mass is set as a nonlinear-linear transformation relationship. In the nonlinear segment, an exponential function is used to simulate the rearrangement and compaction process of the filling particles in the fractures of the water-bearing rock mass. After exceeding the critical compressive displacement, it is converted into a linear function to characterize the stiffness change dominated by pore water pressure after the fractures of the water-bearing rock mass are saturated with water. Thus, a nonlinear-linear transformation deformation constitutive model of the fractures in the water-bearing rock mass under the action of compressive stress wave is established.

5. The method for simulating the dynamic response of fractures in water-bearing rock masses according to claim 1, characterized in that, The mathematical expression for the nonlinear-linear transformation deformation constitutive model of fractures in a water-bearing rock mass under compressive stress wave action is as follows: Under compression: ； In the formula: The part is a non-linear segment. The portion is a linear segment; Under shearing conditions: ； In the formula, σ n and u n These represent the compressive stress and compressive displacement of the fractures in the water-bearing rock mass, respectively. u f and σ f These represent the critical compressive displacement and normal compressive stress when the fractures in the water-bearing rock mass reach saturation, respectively. τ and u s These represent the shear stress and shear displacement of the fractures in the water-bearing rock mass, respectively. a 1 represents the first fitting coefficient of the nonlinear segment. a 2 represents the second fitting coefficient for the nonlinear segment. a 3 represents the compressive stiffness enhancement factor for the transition from nonlinear to linear; a 4 represents the shear stiffness of the fractures in the water-bearing rock mass; τ 0 and φ These represent the shear strength and friction angle of the fracture in the water-bearing rock mass, respectively.

6. The method for simulating the dynamic response of fractures in water-bearing rock masses according to claim 1, characterized in that, Boundary conditions are set for the geometric model of the water-bearing rock mass, specifically as follows: Absorbing boundaries are set on both sides of the geometric model of the water-bearing rock mass to prevent the compressive stress waves propagating and reflecting to the boundary of the geometric model of the water-bearing rock mass from being reflected.

7. The method for simulating the dynamic response of fractures in water-bearing rock masses according to claim 1, characterized in that, A nonlinear-linear transformation deformation constitutive model of fractures in aquifers under compressive stress waves was applied to the fractures in the geometric model of aquifers to conduct simulation experiments, thereby simulating the dynamic response of fractures in aquifers. Specifically: A nonlinear-linear transformation constitutive model of fractures in aquifers under compressive stress waves was applied to the fractures within the geometric model of the aquifer. Simulation experiments were conducted, calculating the critical compressive displacement given the initial thickness, porosity, and saturation of the fractures. During the calculation of compressive stress wave propagation, the compressive displacement of the current fractures in the aquifer was returned in real time. u n and through the critical compressive displacement u f By comparing the results, it is determined whether the current segment is nonlinear or linear. Through the piecewise response of nonlinear exponential hardening and linear bearing, the dynamic response of fractures in water-bearing rock masses is simulated.

8. A simulation system for dynamic response of fractures in water-bearing rock masses, characterized in that, include, The parameter acquisition module measures the initial thickness, initial porosity, and initial saturation of the fractures in the water-bearing rock mass based on its physical properties. Hopkinson bar tests were conducted on fractures in water-bearing rock masses to obtain compressive stress waves. The critical compressibility displacement acquisition module calculates the critical compressibility displacement of the fractures in the water-bearing rock mass using the initial porosity, initial thickness, and initial saturation. The constitutive model building module is used to establish a nonlinear-linear transformation deformation constitutive model of water-bearing rock mass fractures under the action of compressive stress waves based on critical compressive displacement and compressive stress waves, using the discrete element algorithm. The geometric model building module is used to build a geometric model of the water-bearing rock mass and set boundary conditions based on the geometric dimensions of the water-bearing rock mass and the dip angle and location parameters of the fractures in the water-bearing rock mass. The dynamic response simulation module is used to apply the nonlinear-linear transformation deformation constitutive model of water-bearing rock fractures under compressive stress wave action to the water-bearing rock fractures in the geometric model of water-bearing rock mass, and to conduct simulation experiments to realize the dynamic response simulation of water-bearing rock fractures.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the dynamic response simulation method for fractures in water-bearing rock masses as described in any one of claims 1-7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the simulation method for dynamic response of fractures in water-bearing rock masses as described in any one of claims 1-7.

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