Method for accurately calculating wedging process of blasting explosion gas

Abstract

The invention discloses a method for accurately calculating a blasting explosion gas wedging process. The method comprises the following steps: S1, establishing a geometric model of the blasting explosion gas wedging process; s2, performing entity unit grid division on the model, and inserting bonding units among entity units; s3, setting material parameters, bonding unit gas wedging opening parameters and explosion gas mechanical parameters; s4, under the same mechanical time step, the volume of the upper cavity in the fracture area is calculated according to the opening degree of the failure bonding unit; s5, under the same mechanical time step, multiple times of gas circulation calculation are carried out, and the gas pressure of each cavity in the fracture area is obtained; s6, after gas circulation calculation is finished, relevant parameters are calculated and updated according to calculation results in the step S4 and the step S5, and the connection state and the crack geometric characteristics of the bonding units are judged and updated according to the constitutive relation; and S7, the steps S4-S6 are repeated until simulation of the whole blasting rock breaking process is completed.

Description

Technical Field

[0001] The present invention relates to the technical field of blasting analysis, in particular to a method for accurately calculating the wedging process of blasting gas. Background Art

[0002] Blasting technology is widely used in mining, tunneling, and other fields. The blasting rock-breaking process can be understood as the detonation of explosives generating high-energy gases. The high-pressure gas molecules rapidly impact the blasthole wall, forming an explosive stress wave, which creates a crushing zone and an initial fracture zone around the hole wall. When the pressure and temperature in the hole drop to a certain level, the motion state of the gas molecules tends to stabilize, and the gas wedges into the cracks, generating pressure and further promoting crack propagation. However, existing blasting theories do not fully consider the role of explosive gases in the blasting process, and the understanding of the explosive gas rock-breaking mechanism is unclear, which cannot effectively guide blasting operations. Considering that traditional physical experiments cannot measure the explosive gas action process, numerical simulation methods can simulate blasting conditions under different blasting parameters and different explosive gas pressures, accurately predicting the rock fragmentation range and vibration effects during blasting, and can provide a scientific basis for optimizing blasting parameters and improving project quality and safety.

[0003] Currently, there is a lack of a method that can directly and effectively simulate the process of explosive gas-driven crack growth. In most numerical simulations of blasting, the treatment of explosive gas is oversimplified: its changes are usually simulated only by simplifying the calculation of gas pressure or applying an equivalent pressure curve, and the gas pressure is applied as an external load to the blast cavity or crack wall to characterize its effect on the rock mass. However, the actual evolution of explosive gas infiltration and crack growth is extremely complex. As a compressible gas, the volume of explosive gas under high temperature and high pressure is significantly affected by pressure changes. At the same time, its flow rate is high during the process of continuous penetration into the crack, and it is in a non-laminar state, resulting in complex pressure gradient changes in the explosive gas within the crack. Existing methods cannot effectively simulate these key characteristics of the action of explosive gas and cannot accurately simulate the dynamic process of gas-driven crack growth.

[0004] Therefore, it is necessary to propose a method to accurately calculate the wedge penetration process of blasting gas. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for accurately calculating the wedge penetration process of blasting gas, so as to solve the technical problems existing in the background technology.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A method for accurately calculating the wedge penetration process of blasting gas comprises the following steps:

[0008] S1, establish a geometric model of the explosion gas wedge process and set the model shape, size and boundary;

[0009] S2, mesh the model into solid units, insert bonding units between the solid units, initialize the gas cavity list, and establish the corresponding relationship between the grid nodes. When the bonding unit connected to the explosive fails and disconnects, a rupture zone is formed, and the corresponding bonding unit is called a failed bonding unit.

[0010] S3, setting material parameters, bonding unit gas wedge opening parameters and explosion gas mechanics parameters;

[0011] S4, at the same mechanical time step, calculate the gas volume of the cavity above the rupture zone according to the opening of the failed bonding unit;

[0012] S5, in the same mechanical time step, multiple gas cycle calculations are performed to obtain the gas pressure of each cavity on the rupture zone;

[0013] S6, after the gas circulation calculation is completed, using the calculation results in step S4 and step S5, perform Newton's second law equilibrium calculation and update relevant mechanical parameters, and determine and update the connection state and crack geometric characteristics of the bonding unit based on the constitutive relationship;

[0014] S7, repeat steps S4-S6 until the entire blasting and rock breaking process simulation is completed.

[0015] Furthermore, in step S3, the bonding unit gas wedging opening parameters include the bonding unit initial opening, upper limit opening and lower limit opening;

[0016] The explosive gas mechanical parameters include gas adiabatic index, initial gas bulk modulus, initial gas density, initial explosive gas pressure, and explosive position.

[0017] Furthermore, in step S4, the gas volume of the cavity above the rupture zone is calculated according to the opening of the failed bonding unit, which specifically includes the following steps:

[0018] S41, calculate the opening of each failed bonding unit by the following formula:

[0019]

[0020] Where a is the crack opening, a0 is the initial crack opening, and a max and a min are the upper and lower crack opening limits, is the average crack opening;

[0021] S42, calculate the gas volume of each node of a single failed bonding unit based on the opening. If the geometric model established in step S1 is a two-dimensional model, then for the two-dimensional bonding unit, the gas volume is calculated using the following formula:

[0022]

[0023] If the geometric model established in step S1 is a three-dimensional model, then for the three-dimensional bonding unit, the gas volume is calculated by the following formula:

[0024]

[0025] Where L is the length of the common side between a two-dimensional bonded unit and the adjacent solid unit, S is the area of ​​the common surface between a three-dimensional bonded unit and the adjacent solid unit, and n is the number of nodes of the bonded unit. In the two-dimensional model, n is 4, and in the three-dimensional model, n is 6.

[0026] S43, further solve the gas volume of each bonding unit node contained in a cavity on the rupture zone based on the node volume:

[0027]

[0028] S44, sum up the gas volumes occupied by all bonding unit nodes contained in the cavity above the rupture zone to obtain the gas volume of the cavity:

[0029] .

[0030] Furthermore, in step S5, the following steps are specifically included:

[0031] S51, initialization is performed, and the gas volume of all cavities is set to 0;

[0032] S52, update the gas density according to the last gas calculation time step and bulk modulus :

[0033]

[0034]

[0035] Where, is the initial gas density, P0 is the initial gas pressure, and P1 is the current gas pressure, which is obtained from the previous gas calculation time step. is the gas adiabatic index;

[0036] S53, for any cavity in the rupture zone, calculate the influence coefficient of the gas saturation of the cavity in the rupture zone on the gas flow rate:

[0037]

[0038] Where, is the gas saturation of the cavity, obtained from the previous gas calculation time step;

[0039] S54, calculate the gas flow rate at any bonding unit node i in the cavity:

[0040]

[0041] In the formula The gas density of the bonding unit node i and the bonding unit node j connected to it are calculated in this gas calculation time step, The density at the two bonded element nodes for the last gas calculation time step, is the gas permeability coefficient, is the gas pressure difference between the bonding element nodes i and j, and b is a custom coefficient;

[0042] S55, summarize the gas flow rates of all bonded unit nodes in the cavity to obtain the total gas flow rate of the cavity:

[0043]

[0044] S56, calculate the gas saturation of each cavity:

[0045]

[0046] In the formula Calculate the saturation of the cavity for the current gas time step, The saturation of the cavity in the last gas calculation time step is calculated, that is, the saturation of the cavity in step S53 , is the gas calculation time step, and are the volumes of the cavity at the current and previous time steps, respectively, where satisfy ;

[0047] S57, calculate the gas pressure of each cavity based on the flow rate of each cavity:

[0048]

[0049] In the formula The gas pressure in the cavity for the current gas calculation time step, The gas pressure in the cavity for the last gas calculation time step, is the bulk modulus of the gas, Calculate the time step for the gas;

[0050] After calculating the gas pressure of all cavities, the gas pressure distribution of the rupture area cavities in this gas calculation time step is obtained;

[0051] S58, repeat steps S51-S57, continuously update the gas pressure distribution, and stop the calculation after reaching the specified number of gas cycle calculations. The calculation result obtained from the last gas cycle calculation is used as the explosion gas pressure distribution of this mechanical time step to participate in the mechanical calculation.

[0052] Furthermore, in step S54, the gas pressure difference between bonding unit nodes i and j is Calculated by the following formula:

[0053]

[0054] Where, denote the gas pressure at bonding unit node i and bonding unit node j respectively, is the gas density and g is the acceleration due to gravity.

[0055] Furthermore, in step S57, after calculating the gas pressure of each cavity, the gas pressure of each solid unit adjacent to the cavity is also calculated. , for a two-dimensional model, it is calculated by the following formula:

[0056]

[0057] For a three-dimensional model, it is calculated using the following formula:

[0058]

[0059] Where L is the length of the common side between a two-dimensional bonding unit and the adjacent solid unit, and S is the area of ​​the common surface between a three-dimensional bonding unit and the adjacent solid unit. The gas pressure distribution of the explosive gas in the fracture zone during seepage is obtained from this.

[0060] Furthermore, in step S7, specifically, steps S4-S6 are repeated, the gas pressure change is updated by gas, the fracture result is mechanically calculated, and the calculation is terminated when the specified total time step is reached. The simulation of the entire explosive gas blasting and rock breaking process is completed.

[0061] Compared with the prior art, the advantages of the present invention are as follows:

[0062] Existing explosion gas simulation methods cannot accurately simulate the explosion gas-driven crack propagation process; the present invention provides a method for accurately calculating the explosion gas wedging process within the framework of the finite-discrete element method, which solves the above-mentioned problems of existing simulation methods, can accurately calculate the flow velocity changes of the explosion gas in the crack, and accurately characterize the explosion gas-driven crack propagation process, which is of great significance for accurately simulating the explosion gas action process. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the technical solution in this embodiment, the following is a brief introduction to the drawings required for describing the embodiment. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0064] Figure 1 This is a flow chart of a method for accurately calculating the wedge-in process of blasting gas provided by the present invention;

[0065] Figure 2 Schematic diagram of the crack growth process driven by explosive gas

[0066] Figure 3 is a schematic diagram of the cavity on the rupture zone;

[0067] Figure 4 It is a schematic diagram of bonding units in which two-dimensional triangular solid units and three-dimensional tetrahedral solid units are connected respectively;

[0068] Figure 5 It is a schematic diagram of a bonded unit and two triangular solid units connected to it;

[0069] Figure 6 It is a schematic diagram of a bonding unit and two tetrahedral solid units connected to it;

[0070] Figure 7 It is a schematic diagram of a cavity connecting multiple gas percolation channels. DETAILED DESCRIPTION

[0071] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the following further describes how the present invention is implemented in conjunction with the accompanying drawings and specific implementation methods.

[0072] In a specific embodiment, referring to Figure 1 As shown, the present invention provides a method for accurately calculating the wedging process of blasting gas, comprising the following steps:

[0073] S1, establishing a geometric model of the blasting gas wedging process, and setting the model shape, size and boundary; the established geometric model can be a two-dimensional model or a three-dimensional model.

[0074] S2, the model is meshed into solid units, and bonding units are inserted between the solid units. The gas cavity linked list is initialized and the corresponding relationship between the grid nodes is established. When the bonding unit connected to the explosive fails and disconnects, a rupture zone (crack) is formed. The corresponding bonding unit is called a failed bonding unit.

[0075] It can be understood that gas flow occurs between the explosive and the rupture zone, the explosive gas wedges into the rupture zone, and acts on the solid units around the rupture zone, driving the solid to expand outward, causing more bonded units to fail, and the rupture zone continues to expand, thus realizing the simulation of the crack propagation driven by the explosive gas, such as Figure 2 shown.

[0076] S3, set material parameters, bonding unit gas wedge opening parameters and explosion gas mechanical parameters.

[0077] Specifically, the material parameters include material density, elastic modulus, Poisson's ratio, setting the tensile strength of the bonding unit, and setting the model as an absorbing boundary; the bonding unit gas wedge opening parameters include the initial opening of the bonding unit, the upper limit opening and the lower limit opening; the explosive gas mechanical parameters include the gas adiabatic index, the initial gas bulk modulus, the initial gas density, the initial explosive gas pressure, and the position of the explosive.

[0078] S4, at the same mechanical time step, the gas volume of the cavity above the rupture zone is calculated based on the opening of the failed bonding unit.

[0079] like Figure 3 As shown in the figure, the generation of gas pressure is due to the explosion of gas in the cavities on the rupture zone ( Figure 3 1,2…,15) in the fracture zone is caused by gas exchange through the failed bonding units. Therefore, the essence of simulating the process of crack propagation driven by explosion gas is to calculate the pressure effect of explosion gas on the bonding units in the fracture zone. The core of this solution process is to calculate the gas pressure of explosion gas on each cavity above the fracture zone. Before solving the gas pressure, the gas volume of each cavity needs to be calculated. The volume of the cavity above the fracture zone can be calculated according to the opening of the failed bonding unit.

[0080] The calculation of the gas volume of the cavity above the rupture zone based on the opening of the failed bonding unit specifically includes the following steps:

[0081] S41, calculation of the opening of the bonding unit, Figure 4 Taking the bonding element connected by triangular solid element / tetrahedral solid element as an example, for the two-dimensional bonding element, the opening of the bonding element is calculated, such as Figure 5For a bonding unit and two triangular solid units connected to it, the bonding unit nodes are nodes 1, 2, 3, and 4, and the midpoints of the two sides of the bonding unit are nodes 5 and 6. The normal and parallel lines of the line connecting the midpoints of the bonding unit (nodes 5 and 6) are the x-direction and y-direction, and the midpoint O of the line connecting the midpoints is the coordinate origin. A rectangular coordinate system is established. In this coordinate system, the coordinates of the two pairs of relative nodes 1, 2, 3, and 4 and the pair of midpoints 5 and 6 of the quadrilateral face are obtained respectively (x i ,y i ), i=1,2…,6, then the opening of each set of relative points is:

[0082]

[0083] Where y m 、y n They are the vertical coordinates of a set of relative points.

[0084] For a three-dimensional bonded element, when calculating the opening of the bonded element, if Figure 6 For a bonding unit and its two connected tetrahedral units, the bonding unit nodes are nodes 1, 2, 3, 4, 5, and 6, the centroids of the two faces of the bonding unit are nodes 7 and 8, the direction of the line connecting the centroids of the upper and lower faces of the bonding unit (nodes 7 and 8) is the z direction, the two mutually perpendicular directions perpendicular to the z direction are the x direction and the y direction, the centroid 8 of one face of the bonding unit is the coordinate origin, and a spatial rectangular coordinate system is established. In this coordinate system, the coordinates of the two pairs of relative nodes 1, 2, 3, 4 and a pair of midpoints 5 and 6 of the quadrilateral face are obtained respectively (x i ,y i， z i ), i=1,2…,8, then the opening of each group of relative points is O i for:

[0085]

[0086] Where z m 、z n They are the z-axis coordinates of a set of relative points.

[0087] Then the average crack opening of the bonded unit can be calculated:

[0088]

[0089] Where N is the total number of relative nodes and relative midpoints of the bonded element. For two-dimensional triangular elements, N=3; for three-dimensional tetrahedral elements, N=4.

[0090] Then, the opening of each failed bond unit can be calculated by the following formula:

[0091]

[0092] Where a is the crack opening, a0 is the initial crack opening, and a max and a min are the upper and lower crack opening limits, is the average crack opening.

[0093] S42, calculate the gas volume of each node of a single failed bonding unit based on the opening. If the geometric model established in step S1 is a two-dimensional model, then for the two-dimensional bonding unit, the gas volume is calculated using the following formula:

[0094]

[0095] If the geometric model established in step S1 is a three-dimensional model, then for the three-dimensional bonding unit, the gas volume is calculated by the following formula:

[0096]

[0097] Where L is the length of the common side between a two-dimensional bonded unit and the adjacent solid unit, S is the area of ​​the common surface between a three-dimensional bonded unit and the adjacent solid unit, and n is the number of nodes of the bonded unit. In the two-dimensional model, n is 4, and in the three-dimensional model, n is 6.

[0098] S43, further solve the gas volume of each bonding unit node contained in a cavity on the rupture zone based on the node volume:

[0099]

[0100] like Figure 7 As shown in the figure, a cavity connects multiple failed bonding units (gas seepage channels), including bonding unit nodes 1, 2, 3, 4, 5, and 6. Taking bonding unit node 3 as an example, , where V 31 is the gas volume of node 3 in the bonding unit composed of nodes 3, 4, 10, and 9, V 32 is the gas volume of node 3 in the bonding unit composed of nodes 2, 3, 8, and 7.

[0101] S44, sum up the gas volumes occupied by all bonding unit nodes contained in the cavity above the rupture zone to obtain the volume of the cavity:

[0102] .

[0103] S5, in the same mechanical time step, performs multiple gas cycle calculations to obtain the gas pressure of each cavity on the rupture zone. Specifically, it includes the following steps:

[0104] S51, initialization is performed, and the gas volume of all cavities is set to 0;

[0105] S52, update the gas density according to the last gas calculation time step and bulk modulus :

[0106]

[0107]

[0108] Where, is the initial gas density, P0 is the initial gas pressure, and P1 is the current gas pressure, which is obtained from the previous gas calculation time step. is the gas adiabatic index. Since gas is compressible, changes in its pressure will significantly affect changes in gas volume and density, thereby affecting the calculation results. Therefore, during the calculation process, the gas density and bulk modulus need to be updated according to changes in gas pressure.

[0109] S53, for any cavity in the fracture zone, consider the effect of the saturation of the gas when it enters the crack on the gas pressure, and calculate the influence coefficient of the saturation of the cavity in the fracture zone on the flow rate:

[0110]

[0111] Where, is the gas saturation of the cavity, obtained from the previous gas calculation time step.

[0112] S54, calculate the gas flow rate at any bonding unit node i in the cavity:

[0113]

[0114] In the formula The gas density of the bonding unit node i and the bonding unit node j connected to it are calculated in this gas calculation time step, The density at the two bonded element nodes for the last gas calculation time step, is the gas permeability coefficient, is the gas pressure difference between the bonding element nodes i and j, and b is a custom coefficient.

[0115] Gas pressure difference between bonding element nodes i and j Calculated by the following formula:

[0116]

[0117] Where, denote the gas pressure at bonding unit node i and bonding unit node j respectively, is the gas density and g is the acceleration due to gravity.

[0118] like Figure 7 As shown in , a cavity contains multiple bonding unit nodes i (i=1, 2, …, 6). Gas exchange occurs between different cavities through the failed bonding units, and the gas exchange in each cavity is caused by the gas exchange between the bonding unit nodes contained in the cavity and the bonding unit nodes connected to it, as shown in Figure 7 Among nodes 2 and 7, node 3 and node 8, node 3 and node 9, node 4 and node 10, node 5 and node 11, node 6 and node 12, the flow velocity of each bonding unit node in the cavity is first calculated by the above method.

[0119] S55, summarize the gas flow rates of all bonded unit nodes in the cavity to obtain the total gas flow rate of the cavity:

[0120] .

[0121] S56, calculate the gas saturation of each cavity:

[0122]

[0123] In the formula Calculate the gas saturation of the cavity for the current gas time step, The gas saturation of the cavity for the last gas calculation time step, is the gas calculation time step, and are the volumes of the cavity at the current and previous time steps, respectively, where satisfy .

[0124] S57, calculate the gas pressure of each cavity based on the gas flow rate of each cavity:

[0125]

[0126] In the formula The gas pressure in the cavity for the current gas calculation time step, The gas pressure in the cavity for the last gas calculation time step, is the bulk modulus of the gas, is the time step; after the gas pressure of all cavities is calculated, the gas pressure distribution of the rupture area cavities in this gas calculation time step is obtained.

[0127] After calculating the gas pressure of each cavity, the gas pressure of each solid unit adjacent to the cavity is also calculated. , for a two-dimensional model, it is calculated by the following formula:

[0128]

[0129] For a three-dimensional model, it is calculated using the following formula:

[0130]

[0131] Where L is the length of the common side between a two-dimensional bonding unit and the adjacent solid unit, and S is the area of ​​the common surface between a three-dimensional bonding unit and the adjacent solid unit. The gas pressure distribution of the explosive gas in the fracture zone during seepage is obtained from this.

[0132] S58, repeat steps S51-S57, continuously update the gas pressure distribution, and stop the calculation after reaching the specified number of calculation cycles. The calculation result obtained from the last gas cycle calculation is used as the explosion gas pressure distribution of this mechanical time step to participate in the mechanical calculation.

[0133] S6. After the gas circulation calculation is completed, the calculation results in step S4 and step S5 are used to perform Newton's second law equilibrium calculation and update relevant mechanical parameters, such as node force, node displacement, node velocity, solid unit stress, solid unit strain, bonding unit force, bonding unit opening, bonding unit sliding displacement, etc. in the calculation domain, and judge and update the connection status and crack geometric characteristics of the bonding unit based on the constitutive relationship; the calculation method of these parameters belongs to conventional technical means, for example, they can be calculated using the finite discrete element method, which will not be repeated here.

[0134] S7, repeat steps S4-S6, update the gas pressure change through gas, mechanically calculate the fracture result, end the calculation when the specified total time step is reached, and the simulation of the entire explosive gas blasting and rock breaking process is completed.

[0135] Existing explosion gas simulation methods cannot accurately simulate the explosion gas-driven crack propagation process; the present invention provides a method for accurately calculating the explosion gas wedging process within the framework of the finite-discrete element method, which solves the above-mentioned problems of existing simulation methods, can accurately calculate the flow velocity changes of the explosion gas in the crack, and accurately characterize the explosion gas-driven crack propagation process, which is of great significance for accurately simulating the explosion gas action process.

[0136] Finally, it should be noted that the above description is only an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for accurately calculating the wedge penetration process of blasting gas, characterized in that: The following steps are involved: S1, establish a geometric model of the blasting gas wedge process, and set the model shape, size and boundary; S2, mesh the model into solid units, insert bonding units between the solid units, initialize the gas cavity list, and establish the corresponding relationship between the grid nodes. When the bonding unit connected to the explosive fails and disconnects, a rupture zone is formed, and the corresponding bonding unit is called a failed bonding unit. S3, setting material parameters, bonding unit gas wedge opening parameters and explosion gas mechanics parameters; S4, at the same mechanical time step, calculate the gas volume of the cavity above the rupture zone according to the opening of the failed bonding unit; S5, in the same mechanical time step, multiple gas cycle calculations are performed to obtain the gas pressure of each cavity on the rupture zone; S6, after the gas circulation calculation is completed, using the calculation results in step S4 and step S5, perform Newton's second law equilibrium calculation and update relevant mechanical parameters, and determine and update the connection state and crack geometric characteristics of the bonding unit based on the constitutive relationship; S7, repeat steps S4-S6 until the entire blasting and rock breaking process simulation is completed.

2. The method for accurately calculating the wedging process of blasting gas according to claim 1, characterized in that: In step S3, the gas wedging opening parameters of the bonding unit include the initial opening, the upper limit opening and the lower limit opening of the bonding unit; The explosive gas mechanical parameters include gas adiabatic index, initial gas bulk modulus, initial gas density, initial explosive gas pressure, and explosive position.

3. The method for accurately calculating the wedging process of blasting gas according to claim 2, characterized in that: In step S4, the gas volume of the cavity above the rupture zone is calculated according to the opening of the failed bonding unit, which specifically includes the following steps: S41, calculate the opening of each failed bonding unit by the following formula: ； Where a is the crack opening, a0 is the initial crack opening, and a max and a min are the upper and lower crack opening limits, is the average crack opening; S42, calculate the gas volume of each node of a single failed bonding unit based on the opening. If the geometric model established in step S1 is a two-dimensional model, then for the two-dimensional bonding unit, the gas volume is calculated using the following formula: ； If the geometric model established in step S1 is a three-dimensional model, then for the three-dimensional bonding unit, the gas volume is calculated by the following formula: ； Where L is the length of the common side between a two-dimensional bonded unit and the adjacent solid unit, S is the area of ​​the common surface between a three-dimensional bonded unit and the adjacent solid unit, and n is the number of nodes of the bonded unit. In the two-dimensional model, n is 4, and in the three-dimensional model, n is 6. S43, further solve the gas volume of each bonding unit node contained in a cavity on the rupture zone based on the node volume: ； S44, sum up the gas volumes occupied by all bonding unit nodes contained in the cavity above the rupture zone to obtain the gas volume of the cavity: 。 4. The method for accurately calculating the wedging process of blasting gas according to claim 3, characterized in that: In step S5, the following steps are specifically included: S51, initialization is performed, and the gas volume of all cavities is set to 0; S52, update the gas density according to the last gas calculation time step and bulk modulus : ； ； Where, is the initial gas density, P0 is the initial gas pressure, and P1 is the current gas pressure, which is obtained from the previous gas calculation time step. is the gas adiabatic index; S53, for any cavity in the rupture zone, calculate the influence coefficient of the gas saturation of the cavity in the rupture zone on the gas flow rate: ； Where, is the gas saturation of the cavity, obtained from the previous gas calculation time step; S54, calculate the gas flow rate at any bonding unit node i in the cavity: ； In the formula The gas density of the bonding unit node i and the bonding unit node j connected to it are calculated in this gas calculation time step, The gas density at the two bonded element nodes for the last gas calculation time step, is the gas permeability coefficient, is the gas pressure difference between the bonding element nodes i and j, and b is a custom coefficient; S55, summarize the gas flow rates of all bonded unit nodes in the cavity to obtain the total gas flow rate of the cavity: ； S56, calculate the gas saturation of each cavity: ； In the formula Calculate the gas saturation of the cavity for the current gas time step, The gas saturation of the cavity in the last gas calculation time step is calculated as , is the gas calculation time step, and are the volumes of the cavity at the current and previous time steps, respectively, where satisfy ; S57, calculate the gas pressure of each cavity based on the gas flow rate of each cavity: ； In the formula The gas pressure in the cavity for the current gas calculation time step, The gas pressure in the cavity for the last gas calculation time step, is the bulk modulus of the gas, Calculate the time step for the gas; After calculating the gas pressure of all cavities, the gas pressure distribution of the rupture area cavities in this gas calculation time step is obtained; S58, repeat steps S51-S57, continuously update the gas pressure distribution, and stop the calculation after reaching the specified number of gas cycle calculations. The calculation result obtained from the last gas cycle calculation is used as the explosion gas pressure distribution of this mechanical time step to participate in the mechanical calculation.

5. The method for accurately calculating the wedging process of blasting gas according to claim 4, characterized in that: In step S54, the gas pressure difference between bonding unit nodes i and j is Calculated by the following formula: ； Where, denote the gas pressure at bonding unit node i and bonding unit node j respectively, is the gas density and g is the acceleration due to gravity.

6. The method for accurately calculating the wedging process of blasting gas according to claim 5, characterized in that: In step S57, after calculating the gas pressure of each cavity, the gas pressure of each solid unit adjacent to the cavity is also calculated. , for a two-dimensional model, it is calculated by the following formula: ； For a three-dimensional model, it is calculated using the following formula: ； Where L is the length of the common side between a two-dimensional bonding unit and the adjacent solid unit, and S is the area of ​​the common surface between a three-dimensional bonding unit and the adjacent solid unit. The gas pressure distribution of the explosive gas in the fracture zone during seepage is obtained from this.

7. The method for accurately calculating the wedging process of blasting gas according to claim 6, characterized in that: In step S7, specifically, steps S4-S6 are repeated, gas pressure changes are updated by gas, and fracture results are mechanically calculated. The calculation is terminated when the specified total time step is reached, and the entire explosive gas blasting and rock breaking process simulation is completed.

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