Two-dimensional numerical method and device for simulating seepage softening of discontinuous surface of rock mass

Abstract

The application provides a two-dimensional numerical method and device for simulating seepage softening of discontinuous surfaces of rock mass, and the method comprises the following steps: at a current time step, determining a hydraulic joint unit in a two-dimensional model region according to type identification of each joint unit in the two-dimensional model region corresponding to a target rock type; performing softening process calculation on the hydraulic joint unit to determine contact force acting on two walls of the hydraulic joint unit; performing seepage calculation on the hydraulic joint unit to determine first fluid pressure of each node of the hydraulic joint unit; and determining total equivalent node force acting on each node according to the contact force and the first fluid pressure; wherein the total equivalent node force is used to update type identification of a joint unit associated with the hydraulic joint unit. The method not only performs seepage calculation but also performs softening process calculation on the hydraulic joint unit, thereby improving the prediction accuracy of rock mass disasters, so that effective prevention and control strategies can be taken, and is suitable for fluid-structure coupling calculation of discontinuous surfaces of various rocks.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of geotechnical engineering and energy environment, and particularly relates to a two-dimensional numerical method and device for simulating seepage softening of rock mass discontinuous surfaces. BACKGROUND

[0002] Natural rock mass contains a large number of discontinuous surfaces such as joints, fractures and the like, and the seepage softening effect of the rock mass discontinuous surfaces has a huge influence on the engineering stability problems such as rock mass self-sustaining vulnerability and the energy exploitation problems such as reservoir reconstruction. The seepage softening process of the rock mass discontinuous surfaces is essentially a fluid-structure coupling process.

[0003] In the related art, the discrete element and non-continuous deformation analysis methods are mainly used to solve the fluid-structure coupling problem of the rock mass discontinuous surfaces. However, this method has relatively high applicability to jointed rock mass without water-sensitive mechanical damage characteristics, and has relatively poor applicability to high water-sensitive rock mass, thereby affecting the prediction accuracy of the engineering soft rock mass disaster and the selection of the prevention and control strategy. SUMMARY

[0004] The first aspect of the application provides a two-dimensional numerical method for simulating seepage softening of rock mass discontinuous surfaces, comprising:

[0005] In the current time step, the hydraulic joint element in the two-dimensional model region corresponding to the target rock type is determined according to the type identifier of each joint element in the two-dimensional model region corresponding to the target rock type.

[0006] The softening process calculation module is configured to perform softening process calculation on the hydraulic joint element to determine the contact force acting on the two walls of the hydraulic joint element.

[0007] The seepage calculation module is configured to perform seepage calculation on the hydraulic joint element to determine the first fluid pressure acting on each node of the hydraulic joint element.

[0008] The total equivalent node force acting on each node is determined according to the contact force and the first fluid pressure, and the total equivalent node force is used to update the type identifier of the joint element associated with the hydraulic joint element.

[0009] The second aspect of the application provides a two-dimensional numerical device for simulating seepage softening of rock mass discontinuous surfaces, comprising:

[0010] The first determination module is configured to determine the hydraulic joint element in the two-dimensional model region corresponding to the target rock type in the current time step according to the type identifier of each joint element in the two-dimensional model region corresponding to the target rock type.

[0011] The softening process calculation module is configured to perform softening process calculation on the hydraulic joint element to determine the contact force acting on the two walls of the hydraulic joint element.

[0012] a seepage calculation module configured to perform seepage calculation on the hydraulic discontinuity unit to determine a first fluid pressure acting on each node of the hydraulic discontinuity unit;

[0013] a second determination module configured to determine a total equivalent node force acting on each node according to the contact force and the first fluid pressure; wherein the total equivalent node force is used to update a type identifier of a discontinuity unit associated with the hydraulic discontinuity unit.

[0014] To achieve the above object, a third aspect of the present application provides an electronic device, comprising: a processor, and a memory connected with the processor in communication;

[0015] The memory stores computer-executable instructions.

[0016] The processor executes the computer-executable instructions stored in the memory to implement the method according to the first aspect.

[0017] A fourth aspect of the present application provides a computer-readable storage medium, comprising: a processor, and a memory connected with the processor in communication;

[0018] The memory stores computer-executable instructions.

[0019] The processor executes the computer-executable instructions stored in the memory to implement the method according to the first aspect.

[0020] A fifth aspect of the present application provides a computer program product, comprising a computer program which, when executed by a processor, implements the method according to the first aspect.

[0021] The two-dimensional numerical method for simulating seepage softening of discontinuities in rock mass provided by the present application, the electronic device and the storage medium determine the hydraulic discontinuity unit in the two-dimensional model region at the current time step according to the type identifier of each discontinuity unit in the two-dimensional model region corresponding to the target rock type, perform softening process calculation on the hydraulic discontinuity unit, determine the contact force acting on the two walls of the hydraulic discontinuity unit, perform seepage calculation on the hydraulic discontinuity unit, determine the first fluid pressure acting on each node of the hydraulic discontinuity unit, and determine the total equivalent node force acting on the node based on the contact force and the first fluid pressure, so as to update the type identifier of the discontinuity unit associated with the hydraulic discontinuity unit. Thus, for the hydraulic discontinuity unit in the two-dimensional model region, not only seepage calculation but also softening process calculation are performed, so as to improve the accuracy of the total equivalent node force acting on the node of the hydraulic discontinuity unit, improve the prediction accuracy of rock mass disasters, and thus effective prevention and control strategies can be taken, which is suitable for discontinuity fluid-structure coupling calculation of various rocks, and improves the robustness and applicability.

[0022] Additional aspects and advantages of the present application will be partially apparent and partially described in the following description. BRIEF DESCRIPTION OF DRAWINGS

[0023] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the appended drawings.

[0024] Figure 1 A flowchart of a two-dimensional numerical method for simulating seepage softening of rock mass discontinuities provided by an embodiment of the present application;

[0025] Figure 2 A schematic diagram of a joint element type provided by an embodiment of the present application Figure 1 ;

[0026] Figure 3 A schematic diagram of a joint element provided by an embodiment of the present application

[0027] Figure 4 A schematic diagram of a joint element type provided by an embodiment of the present application Figure 2 ;

[0028] Figure 5 A schematic diagram of a fluid pressure calculation equivalent node force provided by an embodiment of the present application

[0029] Figure 6 A structural schematic diagram of a two-dimensional numerical device for simulating seepage softening of rock mass discontinuities provided by an embodiment of the present application. DETAILED DESCRIPTION

[0030] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like reference numerals are used throughout the drawing figures to refer to the same or like elements or elements having the same or similar functionality. The embodiments described below are exemplary and intended to be illustrative of the present application, and are not to be construed as limiting.

[0031] A two-dimensional numerical method and device for simulating seepage softening of rock mass discontinuities of an embodiment of the present application are described below with reference to the attached drawing figures.

[0032] In some embodiments, the discrete element and non-continuous deformation analysis method mainly simplifies the rock mass discontinuities into parallel plates, uses the cubic law to establish a relationship between the opening of the rock mass discontinuities and the fluid flow, and realizes the fluid-structure coupling calculation of the rock mass discontinuities by updating the fluid pressure acting on the two walls of the discontinuities and the opening of the discontinuities. However, this method has poor applicability for high water-sensitive rock masses, thereby affecting the prediction accuracy of engineering soft rock mass disasters and the selection of prevention and control strategies.

[0033] Based on this, the embodiment of the present application provides a two-dimensional numerical method for simulating seepage softening of discontinuous surfaces of rock mass. Figure 1 A flowchart of the two-dimensional numerical method for simulating seepage softening of discontinuous surfaces of rock mass provided by the embodiment of the present application is shown in the figure.

[0034] As shown in the figure, the two-dimensional numerical method for simulating seepage softening of discontinuous surfaces of rock mass includes the following steps: Figure 1

[0035] Step 101, at the current time step, according to the type identification of each joint element in the two-dimensional model area corresponding to the target rock type, determine the hydraulic joint element in the two-dimensional model area.

[0036] Wherein, the target rock type can be any rock type. For example, the target rock type can be any rock type in mudstone, shale, argillaceous sandstone, granite and marble.

[0037] In the present application, a discrete fracture network line can be generated in the two-dimensional model area of the target rock type to represent the discontinuous surface in the rock mass, which is used as a grid boundary line to subdivide into a triangular solid element grid, as shown in the figure. Figure 2 After that, the node topology of the triangular solid element can be updated, so that all triangular solid elements have independent node numbers, thereby embedding a joint element between adjacent triangular solid elements, which can simulate the continuous-fracture process, and the joint element has four nodes. Figure 2 The dividing area between the two triangles in the figure can be considered as a joint element.

[0038] In order to facilitate understanding of the joint element, the following will be described in conjunction with the figure. Figure 3 Figure 3 In the figure, before updating the node topology, the two triangular solid elements have a common node a and node b. After updating the node topology, the two triangular solid elements have independent node numbers, the node a in the upper triangular solid element is numbered as a1, and the node b is numbered as b1. In the lower triangular solid element, the node a is numbered as a2, and the node b is numbered as b2. If a joint element is embedded between the two triangular solid elements, the four nodes of the joint element are node a1, node a2, node b1 and node b2.

[0039] It should be noted that, Figure 3 In the figure, the coordinates of node a1 and node a2 can be the same or different, and the coordinates of node b1 and node b2 can be the same or different, which is not limited.

[0040] In some embodiments, the joint elements in the two-dimensional model area can be divided into fracture joint elements representing discontinuous surfaces and cohesive joint elements representing continuous surfaces, as shown in the figure. Figure 2 ​​The cohesive joint unit is transformed into a fractured joint unit under certain conditions.

[0041] In some embodiments, at the initial time step, the discontinuous surfaces in the two-dimensional model region are marked as fractured joint units, the continuous surfaces between the remaining triangular solid units are marked as cohesive joint units, and the cohesive joint units on the hydraulic boundary are marked as hydraulic joint units. At the subsequent time steps, the fractured joint units in communication with the hydraulic boundary are also marked as hydraulic joint units.

[0042] For example, Figure 2 The circular hole in the figure represents a water hole, and the boundary of the water hole is the hydraulic boundary. Figure 2 The two-dimensional model region shown in the figure has cohesive joint units, fractured joint units, and hydraulic joint units, which change over time Figure 2 Some of the fractured joint units in the figure are transformed into hydraulic joint units, such as Figure 4 as shown in the figure.

[0043] In the present application, at the current time step, each joint unit in the two-dimensional model region can be traversed, and the type of each joint unit in the two-dimensional model region can be determined according to the type identifier of each joint unit, so that the hydraulic joint units in the two-dimensional model region can be determined.

[0044] For example, the type identifier of a cohesive joint unit is 0, the type identifier of a fractured joint unit is 1, and the type identifier of a hydraulic joint unit is 2. If the type identifier of a joint unit is 2, it can be determined that the joint unit is a hydraulic joint unit.

[0045] It should be noted that the above type identifier is only an example, and can be determined according to actual needs. The present application does not limit this.

[0046] In some embodiments, for a cohesive joint unit in the two-dimensional model region, a cohesive transition zone model can be used to calculate the stress state of the cohesive joint unit, the stress state including normal stress and shear stress, and the normal stress and shear stress are equivalent to node forces, that is, the stress state is converted into equivalent node forces, and the equivalent node forces are applied to the four nodes of the cohesive joint unit.

[0047] For example, the stress state can be calculated using the following formulas (1) and (2):

[0048] (1)

[0049] (2)

[0050] wherein the stress state includes normal stress and shear stress ; a shape function, , D a dimensionless damage parameter, a , b and c are fitting parameters of an empirical curve; a tensile strength; a normal stress on the interaction edge, which is the edge between two triangular solid elements constituting a fractured joint element; c and are the cohesion and internal friction angle of the rock, respectively.

[0051] In some embodiments, for a fractured joint element in a two-dimensional model region, a discrete contact algorithm can be employed to solve the contact forces between the two walls of the fractured joint element and to equivalently apply the contact forces as nodal forces, i.e., to convert the contact forces into equivalent nodal forces, which are applied to the four nodes of the fractured joint element. The contact forces between the two walls of the fractured joint element can include a normal repulsive stress and a tangential frictional stress.

[0052] Illustratively, a distributed contact force penalty method can be employed to calculate the normal repulsive stress between contact elements (i.e., contact pairs), which can refer to the triangular solid elements on the two sides of a joint element. For example, it can be assumed that the contact pairs can penetrate each other, and the normal repulsive stress can be calculated by calculating the size and shape of the overlapping region and introducing a normal contact stiffness.

[0053] Illustratively, a friction model that takes into account the characteristics of discontinuous surfaces can be employed to calculate the tangential frictional stress between the two walls of the fractured joint element. The formula for calculating the tangential frictional stress can be as shown in equation (3)

[0054]

[0055] (3)

[0056] wherein, h is the length of the edge of the triangular solid element; is the tangential contact stiffness; is the peak shear strength, , a normal stress on the interaction edge, is the basic friction angle, JRC is the roughness coefficient of the discontinuous surface, JCS is the wall rock strength, other optimized JRC-JCS formulas and three-dimensional shear strength theoretical formulas can also be employed; is the residual shear strength, , is the residual friction angle; ​the sign of the slip distance variable on the interaction edge is the same as the sign of the slip distance variable on the interaction edge , is the time step, is the relative velocity of the interaction edge; is the peak shear strength corresponding to the slip distance, .

[0057] At step 102, a softening process calculation is performed on the water joint unit to determine the contact force acting on the two walls of the water joint unit.

[0058] The contact force acting on the two walls of the water joint unit can include normal repulsive stress, tangential friction stress, etc.

[0059] In some embodiments, a discrete contact algorithm can be used to solve the contact force acting on the two walls of the water joint unit. The contact force also includes normal repulsive stress and tangential friction stress. The calculation method of the normal repulsive stress can refer to the above calculation of the normal repulsive stress acting on the two walls of the water joint unit, which will not be repeated here.

[0060] Due to the softening effect of the water joint unit, with the increase of the immersion time, the wall strength of the discontinuous surface may be smaller, and with the increase of the immersion time, the basic friction angle, the residual friction angle, etc. are also affected.

[0061] Based on this, in some embodiments, a friction model considering the characteristics of the discontinuous surface can be used to determine the tangential friction stress acting on the two walls of the water joint unit by combining the decay of the wall strength and the decay of the friction angle. Since the decay of the strength and the decay of the friction angle are considered, the accuracy of the tangential friction stress can be improved.

[0062] For example, the interface softening function and the friction angle decay function corresponding to the target rock type can be obtained, the basic friction angle is corrected according to the interface softening function to obtain the corrected basic friction angle, the wall strength parameter is corrected according to the friction angle decay function to obtain the corrected wall strength parameter, the corrected peak shear strength is determined according to the corrected basic friction angle and the corrected wall strength parameter, and the tangential friction stress is determined according to the corrected peak shear strength.

[0063] The interface softening function can be a decay function of the parameter of the wall strength of the discontinuous surface with the immersion time, and the friction angle decay function can be a decay function of the friction angle with the immersion time. The friction angle here can include the basic friction angle, the residual friction angle, etc.

[0064] The parameter for measuring the strength of the discontinuity wall surface can include uniaxial compressive strength (UCS), wall rock strength, etc.

[0065] For example, the sliding distance variable and the peak shear strength corresponding to the sliding distance on the interaction edge of the hydraulic joint unit can be determined, if the absolute value of the sliding distance variable is less than or equal to the sliding distance, the tangential friction stress is determined according to the corrected peak shear strength and the sliding distance variable, if the absolute value of the sliding distance variable is greater than the sliding distance, the residual friction angle is corrected according to the friction angle attenuation function, the corrected residual shear strength is determined according to the corrected residual friction angle, and the tangential friction stress is determined according to the corrected peak shear strength, the sliding distance variable and the corrected residual shear strength.

[0066] For example, the tangential friction stress can be determined according to the ratio between the absolute value of the sliding distance variable and the absolute value of the sliding distance, the corrected peak shear strength and the corrected residual shear strength.

[0067] For example, the tangential friction stress can be calculated by using the above formula (3), in which the corrected peak shear strength and the corrected residual shear strength are obtained by using the following formula (4) and formula (5):

[0068] (4)

[0069] (5)

[0070] wherein, is the friction angle attenuation function; is the interface softening function; represents the immersion time, i.e., the existence duration of the hydraulic joint unit, for example, a fracture joint unit is marked as a hydraulic joint unit at a time step , then the immersion time is , i.e., the immersion time .

[0071] For example, to calculate the tangential friction stress of the hydraulic joint unit at the current time step, the immersion time can be determined according to the current time step, and then the peak shear strength and the residual shear strength are calculated according to formula (4) and formula (5), and then the tangential friction stress of the hydraulic joint unit is calculated by substituting them into formula (3).

[0072] Step 103, performing seepage calculation on the hydraulic joint unit to determine the first fluid pressure acting on each node of the hydraulic joint unit.

[0073] In the present application, for each node in the hydraulic joint unit, a first fluid pressure of water in the hydraulic joint unit acting on the node at a current time step can be calculated.

[0074] In some embodiments, for any one of the nodes, the first fluid pressure of the any one node at the current time step can be determined according to the second fluid pressure of the any one node at a previous time step.

[0075] For example, if the second fluid pressure of the any one node at the previous time step is greater than a first threshold value, the first fluid pressure can be determined according to the second fluid pressure and a sum of fluxes of all hydraulic joint units to which the any one node belongs. For example, the first threshold value can be 0.

[0076] For example, if the second fluid pressure is less than the first threshold value, the second fluid pressure can be assigned to the first threshold value, and a second node saturation of the any one node at the current time step can be determined according to a first node saturation of the any one node at the previous time step.

[0077] The second node saturation can be used to determine the flux of the hydraulic joint unit of which the any one node is a starting node in the seepage direction.

[0078] For example, if the first node saturation of the any one node at the previous time step is less than a second threshold value, the second node saturation of the any one node at the current time step can be determined according to the first node saturation and the sum of the fluxes of all hydraulic joint units to which the any one node belongs. For example, the second threshold value can be 1.

[0079] For example, if the first node saturation of the any one node at the previous time step is greater than the second threshold value, the first node saturation can be assigned to the second threshold value, and the first fluid pressure can be determined according to the second fluid pressure and the sum of the fluxes of all hydraulic joint units to which the any one node belongs.

[0080] As an example, for any one node of the hydraulic joint unit, a sum of fluxes of all hydraulic joint units connected to the node can be calculated wherein i is a number of the hydraulic joint unit, i =0, 1, 2, 3, …, n. Wherein, the number of the hydraulic joint unit connected to the node is i The flux of the hydraulic joint unit, i.e. the flux between two adjacent nodes in the seepage direction can be calculated by using the following formula (6):

[0081] (6)

[0082] wherein, μ is a viscosity of the fluid; L is a length of the hydraulic joint unit; is the opening of the hydraulic joint unit; is the saturation empirical function, which can be expressed as where is the time step the saturation of the initial node flowing to the node in the seepage direction; is the pressure difference between the two adjacent nodes in the seepage direction, where, is the density of the fluid, g is the gravitational acceleration, and is and are the elevations of the two adjacent nodes, respectively.

[0083] Further, the fluid pressure of the node can be calculated using the following formula (7) according to the flow of all hydraulic joint units connected to the node and

[0084] (7)

[0085] where, and are the fluid pressures of the node at time steps t and t respectively; K is the bulk modulus of the fluid; is the time step interval; , where, and are the volumes of the node at time steps and respectively. If , the time step is calculated using formula (7), and if , the fluid is not enough to fill the node cavity, then and the saturation of the node is updated using the following formula (8):

[0086] (8)

[0087] where, and are the saturations of the node at time steps and respectively. If , then , the time step updates the saturation of the node using formula (8) and does not calculate the fluid pressure of the node using formula (7); if , then , the time step ​The fluid pressure of the node is calculated by using formula (7).

[0088] For example, the seepage direction of a certain hydraulic joint unit is from node d to node e. When the fluid pressure of node e is calculated, the node saturation of node e is updated. When the flow between node d and node e is calculated, the saturation of node e is used.

[0089] In step 104, the total equivalent node force acting on each node is determined according to the contact force and the first fluid pressure.

[0090] The total equivalent node force acting on each node of the hydraulic joint unit can be used to update the type identification of the joint unit associated with the hydraulic joint unit.

[0091] For example, the joint unit associated with the hydraulic joint unit can include a cohesive joint unit, a fractured joint unit, etc. In this application, the contact force and the first fluid pressure of each node can be converted into equivalent node forces. For any node of the hydraulic joint unit, the total equivalent node force acting on the node can be determined according to the two equivalent node forces.

[0092] As an example, the fluid pressure of each node acts as a surface pressure on the two walls of the hydraulic joint unit. The fluid pressure is converted into an equivalent node force by formula (9) as shown in formula (9): Figure 5

[0093] (9)

[0094] wherein, is the fluid pressure of the two walls of the hydraulic joint unit, , p 1 is the fluid pressure of node 0 and node 3, p 1 is the fluid pressure of node 1 and node 3; 、 、 and are the coordinates of the four nodes of the hydraulic joint unit shown in formula (9). Figure 5

[0095] ​​Since the hydraulic joint unit has common nodes with other joint units such as the cohesive joint unit, the fracture joint unit, and the like, that is, the nodes of the hydraulic joint unit can also belong to the cohesive joint unit, the fracture joint unit, and the like. Based on this, in some embodiments, for any node in the hydraulic joint unit, all joint units to which the node belongs can be determined, and the sum of the equivalent node forces obtained by performing the corresponding type of mechanical calculation on all the joint units is the total equivalent node force. For example, a node belongs to the hydraulic joint unit A1, the cohesive joint unit A2, and the fracture joint unit A3. The total equivalent node force acting on the node can be obtained by adding the equivalent node force obtained according to the contact force acting on the two walls of the hydraulic joint unit A1 and the fluid pressure of the node, the equivalent node force obtained according to the stress state of the cohesive joint unit A2, and the equivalent node force obtained according to the contact force acting on the two walls of the fracture joint unit A3.

[0096] For any node in the hydraulic unit, the acceleration can be determined according to the total equivalent node force of the node and the mass of the node, the velocity can be determined according to the acceleration and the time step interval, the displacement amount can be determined according to the velocity and the time step interval, the coordinates of the node can be updated according to the displacement amount to obtain the updated coordinates of the node, and the type identifier of the joint unit associated with the hydraulic unit can be updated according to the updated coordinates of the node. The mass of the node can be equal to one-third of the mass of a triangular solid element.

[0097] For example, the updated coordinates of other nodes in the associated joint unit can be determined in the same way, and the type identifier of the joint unit associated with the hydraulic unit can be updated according to the updated coordinates of the nodes in the associated joint unit.

[0098] For example, the associated joint unit includes a cohesive joint unit. According to the updated coordinates of the nodes of the cohesive joint unit, it can be determined whether the cohesive joint unit has been damaged. If it has been damaged, the type identifier of the cohesive joint unit can be updated to the type identifier of the fracture joint unit. Then, for the fracture joint unit, it can be determined whether the fracture joint unit is a hydraulic joint unit. If it is, the type identifier of the fracture joint unit is updated to the type identifier of the hydraulic joint unit, and then the softening process calculation and the seepage calculation can be performed on the hydraulic joint unit.

[0099] For example, if the normal distance between the midpoints of the two edges of the cohesive joint unit is greater than the normal distance threshold, it can be considered that the cohesive joint unit is damaged, so that the cohesive joint unit is determined to be a fracture joint unit.

[0100] For example, if the lateral slip distance of the cohesive joint unit is greater than the lateral slip distance threshold, it can be considered that the cohesive joint unit is damaged, so that the cohesive joint unit is determined to be a fracture joint unit.

[0101] For example, if the half of the sum of the normal distance of the bonded joint element and the square of the lateral slip distance is out of the preset envelope region, it can be considered that the bonded joint element is damaged, so as to determine that the bonded joint element becomes a fractured joint element.

[0102] For example, the method for determining whether the fractured joint element is a hydraulic joint element can be as follows: it can be determined whether the fractured joint element is in communication with the hydraulic boundary, if the fractured joint element is in communication with the hydraulic boundary, it can be determined that the fractured joint element becomes a hydraulic joint element.

[0103] For example, it can be determined whether any node in the fractured joint element belongs to any hydraulic joint element, if any node in the fractured joint element belongs to any hydraulic joint element, it can be considered that the fractured joint element is in communication with the hydraulic boundary, so as to determine that the fractured joint element is a hydraulic joint element.

[0104] It can be understood that for each node of the joint element in the two-dimensional model region, the acceleration can be determined according to the sum of all equivalent node forces acting on the node and the mass of the node, the velocity can be determined according to the acceleration and the time step interval, the displacement amount can be determined according to the velocity and the time step interval, and the coordinates of the node can be updated according to the displacement amount, so as to determine whether the bonded joint element in the two-dimensional model region is damaged according to the updated coordinates of the nodes of the bonded joint element, if the bonded joint element is damaged, the type identifier of the bonded joint element can be updated to the type identifier of the fractured joint element. Then for the fractured joint element, it can be determined whether the fractured joint element is a hydraulic joint element, if yes, the type identifier of the fractured joint element is updated to the type identifier of the hydraulic joint element, and the softening process calculation and the seepage calculation of the hydraulic joint element are performed.

[0105] For example, the type identifier of the bonded joint element is 0, the type identifier of the fractured joint element is 1, and the type identifier of the hydraulic joint element is marked as 2, if a bonded joint element is damaged, that is, becomes a fractured joint element, the type identifier of the joint element is updated from 0 to 1, if the fractured joint element is a hydraulic joint element, the type identifier of the joint element can be updated from 1 to 2.

[0106] In the embodiment of the present application, the type identifier of each joint element in the two-dimensional model region corresponding to the target rock type is used to determine the hydraulic joint element in the two-dimensional model region at the current time step, the softening process calculation is performed on the hydraulic joint element, the contact force acting on the two walls of the hydraulic joint element is determined, the seepage calculation is performed on the hydraulic joint element, the first fluid pressure acting on each node of the hydraulic joint element is determined, and the total equivalent node force acting on the node is determined based on the contact force and the first fluid pressure, so as to update the type identifier of the joint element associated with the hydraulic joint element. Therefore, for the hydraulic joint element in the two-dimensional model region, not only the seepage calculation is performed, but also the softening process calculation is performed, so that the accuracy of the total equivalent node force acting on the node of the hydraulic joint element can be improved, the prediction accuracy of the rock mass disaster is improved, and then an effective prevention and control strategy can be adopted. The present application is applicable to the discontinuous surface fluid-structure coupling calculation of various rocks, and the robustness and applicability are improved.

[0107] In addition, when the softening process calculation is performed on the hydraulic joint element, the decay of the discontinuous surface wall strength with the immersion time and the decay of the friction angle with the immersion time are considered, the corrected peak shear strength and the corrected residual friction angle are obtained based on the interface softening function and the friction angle decay function, and the tangential friction stress of the hydraulic joint element is calculated based on the corrected peak shear strength and the corrected residual friction angle, so as to improve the accuracy of the tangential friction stress, and further improve the accuracy of the equivalent node force obtained by converting the tangential friction stress.

[0108] In order to realize the above-mentioned embodiments, the present application further provides a two-dimensional numerical device for simulating seepage softening of rock mass discontinuous surface.

[0109] Figure 6 A structure schematic diagram of a two-dimensional numerical device for simulating seepage softening of rock mass discontinuous surface provided by the embodiment of the present application.

[0110] As shown in Figure 6 The two-dimensional numerical device for simulating seepage softening of rock mass discontinuous surface 600 comprises:

[0111] A first determination module 610 is configured to determine the hydraulic joint element in the two-dimensional model region according to the type identifier of each joint element in the two-dimensional model region corresponding to the target rock type at the current time step;

[0112] A softening process calculation module 620 is configured to perform softening process calculation on the hydraulic joint element to determine the contact force acting on the two walls of the hydraulic joint element;

[0113] A seepage calculation module 630 is configured to perform seepage calculation on the hydraulic joint element to determine the first fluid pressure acting on each node of the hydraulic joint element;

[0114] The second determining module 640 is configured to determine a total equivalent node force acting on each node according to the contact force and the first fluid pressure, and update a type identifier of a joint unit associated with the water-joint unit according to the total equivalent node force.

[0115] Further, in a possible implementation of the embodiment of the present application, the contact force includes a tangential friction stress, and the softening process calculation module 620 is configured to:

[0116] obtain an interface softening function and a friction angle attenuation function corresponding to the target rock type, wherein the interface softening function is an attenuation function of a parameter for measuring wall surface strength of a discontinuous surface with immersion time, and the friction angle attenuation function is an attenuation function of a friction angle with immersion time, and the friction angle includes a basic friction angle;

[0117] correct the basic friction angle according to the interface softening function to obtain a corrected basic friction angle;

[0118] correct the wall surface strength parameter according to the friction angle attenuation function to obtain a corrected wall surface strength parameter;

[0119] determine a corrected peak shear strength according to the corrected basic friction angle and the corrected wall surface strength parameter;

[0120] determine the tangential friction stress according to the corrected peak shear strength.

[0121] Further, in a possible implementation of the embodiment of the present application, the friction angle further includes a residual friction angle, and the softening process calculation module 620 is configured to:

[0122] determine a sliding distance variable of an interaction edge of the water-joint unit and a sliding distance corresponding to the peak shear strength;

[0123] determine the tangential friction stress according to the corrected peak shear strength and the sliding distance variable in response to an absolute value of the sliding distance variable being less than or equal to the sliding distance;

[0124] determine a corrected residual shear strength according to the residual friction angle corrected according to the friction angle attenuation function in response to the absolute value of the sliding distance variable being greater than the sliding distance;

[0125] determine the tangential friction stress according to the corrected peak shear strength, the sliding distance variable, and the corrected residual shear strength.

[0126] Further, in a possible implementation manner of the embodiment of the present application, the seepage calculation module 630 is configured to:

[0127] For any one of the nodes, the first fluid pressure of the any one of the nodes at the current time step is determined according to the second fluid pressure of the any one of the nodes at a previous time step.

[0128] Further, in a possible implementation manner of the embodiment of the present application, the seepage calculation module 630 is configured to:

[0129] In response to the second fluid pressure being greater than a first threshold value, the first fluid pressure is determined according to the second fluid pressure and a flow sum of all hydraulic joint units to which the any one of the nodes belongs.

[0130] Further, in a possible implementation manner of the embodiment of the present application, the device can further include:

[0131] The third determination module is configured to, in response to the second fluid pressure being less than the first threshold value, assign the second fluid pressure as the first threshold value, and determine a second node saturation of the any one of the nodes at the current time step according to a first node saturation of the any one of the nodes at the previous time step.

[0132] The second node saturation is used to determine a flow of a hydraulic joint unit of which the any one of the nodes is a starting node in a seepage direction.

[0133] Further, in a possible implementation manner of the embodiment of the present application, the third determination module is configured to:

[0134] In response to the first node saturation being less than a second threshold value, the second node saturation is determined according to the first node saturation and the flow sum.

[0135] It should be noted that the foregoing explanation and description of the two-dimensional numerical method for simulating seepage softening of discontinuous surfaces of rock mass also applies to the two-dimensional numerical device for simulating seepage softening of discontinuous surfaces of rock mass, which will not be repeated here.

[0136] In the embodiment of the present application, for the hydraulic joint units in the two-dimensional model region, not only seepage calculation but also softening process calculation is performed, so that the accuracy of the total equivalent node force acting on the nodes of the hydraulic joint units can be improved, the prediction accuracy of the rock mass disaster is improved, and then effective prevention and control strategies can be taken, which is applicable to the discontinuous surface fluid-structure coupling calculation of various rocks, and the robustness and applicability are improved.

[0137] To achieve the above-mentioned embodiments, the present application further provides an electronic device, comprising: a processor, and a memory connected with the processor in communication; the memory stores computer execution instructions; the processor executes the computer execution instructions stored in the memory to realize the method provided by the foregoing embodiments.

[0138] To achieve the above-mentioned embodiments, the present application further provides a computer readable storage medium, wherein the computer readable storage medium stores computer execution instructions, and the computer execution instructions are executed by a processor to realize the method provided by the foregoing embodiments.

[0139] To achieve the above-mentioned embodiments, the present application further provides a computer program product, comprising a computer program, wherein the computer program is executed by a processor to realize the method provided by the foregoing embodiments.

[0140] The collection, storage, use, processing, transmission, provision and disclosure of user personal information involved in the present application comply with relevant laws and regulations and do not violate public order and good customs.

[0141] It should be noted that the personal information from the user should be collected for legal and reasonable purposes, and should not be shared or sold outside these legal uses. In addition, such collection / sharing should be carried out after the user's informed consent is received, including but not limited to informing the user to read the user agreement / user notice before the user uses the function, and signing the agreement / authorization including authorization of relevant user information. In addition, any necessary steps should be taken to protect and ensure access to such personal information data, and to ensure that other people with access to personal information data comply with their privacy policy and processes.

[0142] The present application is expected to provide embodiments in which the user can selectively prevent the use or access of personal information data. That is, the present disclosure is expected to provide hardware and / or software to prevent or prevent access to such personal information data. Once the personal information data is no longer needed, the risk is minimized by limiting data collection and deleting data. In addition, such personal information is de-identified, as applicable, to protect the privacy of the user.

[0143] In the foregoing detailed description, reference is made to descriptive terms such as "one embodiment", "some embodiments", "an example", "a specific example" or "some examples" etc. for describing various embodiments of the application. These descriptive terms are used for the purpose of the description and are not meant to limit or restrict the scope of the application. The use of these terms does not imply that the described feature is essential to the application or that it will be combined with other features as described to achieve the advantages described. The scope of the application is defined by the appended claims.

[0144] Furthermore, the terms "first", "second", "third", "fourth", "fifth" and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily presented chronologically. It is to be understood that the describing of a certain feature as "first", "second", "third", "fourth", "fifth" etc. does not mean that the same feature will not be described as such at a later stage. The terms "first", "second", "third", "fourth", "fifth" etc. are used to distinguish between different features, and do not mean an ordering of the features in time or in any other way. The terms "first", "second", "third", "fourth", "fifth" etc. are used to distinguish between different features, and do not mean an ordering of the features in time or in any other way.

[0145] Any process or method described in a flowchart or otherwise described herein can be understood as representing code modules, segments, or portions of code that include one or more executable instructions for implementing specific logic functions (or steps) of the process, and alternate implementations are possible. In this description and in the claims, the terms "code modules", "code segments", or "code portions" are used to generally refer to information that is a tangible representation of one or more

[0146] The logic and / or steps represented in flow diagrams or otherwise described herein, for example, can be considered as a sequence of executable instructions, and can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For purposes of this specification, a "computer-readable medium" can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable medium can be a product of the manufacturing and / or processing. The computer-readable medium can include, but is not limited to, the following: an electronic connection (an electronic device having one or more wires), a portable computer diskette (a magnetic device), a RAM (random access memory), a ROM (read-only memory), an EPROM (erasable programmable ROM) or Flash memory, an optical fiber device, and a portable CD ROM. Additionally, the computer-readable medium can be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via, for example, an optical scanner, then compiled, interpreted, or otherwise processed, and stored in a computer memory in order to be executed.

[0147] It should be understood that aspects of the application can be implemented in hardware, software, firmware or combinations thereof. In the above embodiments, various steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. As such, in some embodiments, the steps or methods can be implemented in a combination of hardware and software. If implemented in hardware, as in another embodiment, any of the above techniques can be implemented with or without the use of a programmable data processing apparatus, using any of the following technologies: discrete logic circuitry having logic gates for implementing logic functions upon an application of data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), and the like.

[0148] Those of skill in the art would understand that the steps or methods carried out in the above-described embodiments can be carried out by program instructions executed by a processor, and that the program instructions can be stored in a computer readable storage medium. The program instructions, when executed by the processor, can cause the processor to carry out the steps or methods of the embodiments.

[0149] In addition, each of the functional units in the various embodiments of the present application can be integrated in one processing module, or each of the units can be physically present separately, or two or more units can be integrated in one module. The integrated module can be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer readable storage medium.

[0150] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A two-dimensional numerical method for simulating the seepage softening of discontinuities in rock masses, characterized in that, The method comprises the following steps: At a current time step, determining a hydraulic joint element in a two-dimensional model region corresponding to a target rock type according to a type identifier of each joint element in the two-dimensional model region; Performing a softening process calculation on the hydraulic joint element to determine a contact force acting on two walls of the hydraulic joint element; Performing a seepage calculation on the hydraulic joint element to determine a first fluid pressure acting on each node of the hydraulic joint element; Determining a total equivalent node force acting on each node according to the contact force and the first fluid pressure; wherein the total equivalent node force is used to update a type identifier of a joint element associated with the hydraulic joint element; The contact force includes a tangential friction stress, and the performing of the softening process calculation on the hydraulic joint element to determine the contact force acting on the two walls of the hydraulic joint element comprises: Obtaining an interface softening function and a friction angle decay function corresponding to the target rock type; wherein the interface softening function is a decay function of a parameter for measuring the strength of the wall surface of the discontinuous surface with the immersion time, and the friction angle decay function is a decay function of the friction angle with the immersion time; wherein the friction angle includes a basic friction angle; According to the interface softening function, the basic friction angle is corrected to obtain a corrected basic friction angle; According to the friction angle decay function, the wall surface strength parameter is corrected to obtain a corrected wall surface strength parameter; According to the corrected basic friction angle and the corrected wall surface strength parameter, a corrected peak shear strength is determined; According to the corrected peak shear strength, the tangential friction stress is determined.

2. The method of claim 1, wherein, The friction angle also includes a residual friction angle, and the determination of the tangential friction stress according to the corrected peak shear strength comprises: Determining a sliding distance variable on the interaction edge of the hydraulic joint element and a sliding distance corresponding to the peak shear strength; In response to an absolute value of the sliding distance variable being less than or equal to the sliding distance, the tangential friction stress is determined according to the corrected peak shear strength and the sliding distance variable; In response to the absolute value of the sliding distance variable being greater than the sliding distance, the residual friction angle is corrected according to the friction angle decay function, and a corrected residual shear strength is determined according to the corrected residual friction angle; The tangential friction stress is determined according to the corrected peak shear strength, the sliding distance variable, and the corrected residual shear strength.

3. The method of claim 1, wherein, The seepage calculation on the hydraulic joint element to determine the first fluid pressure acting on each node of the hydraulic joint element comprises: For any node in the nodes, the first fluid pressure of the any node at the current time step is determined according to a second fluid pressure of the any node at a previous time step.

4. The method of claim 3, wherein, The determination of the first fluid pressure of the any node at the current time step according to the second fluid pressure of the any node at the previous time step comprises: in response to the second fluid pressure being greater than a first threshold, determining the first fluid pressure according to the second fluid pressure and a flow sum of all hydraulic-joint elements to which the any node belongs.

5. The method of claim 4, wherein, The method further comprises: in response to the second fluid pressure being less than the first threshold, assigning the second fluid pressure as the first threshold, and determining a second node saturation of the any node at the current time step according to a first node saturation of the any node at the previous time step; wherein the second node saturation is used to determine a flow of a hydraulic-joint element to which the any node serves as a starting node in a seepage direction.

6. The method of claim 5, wherein, The determining the second node saturation according to the first node saturation of the any node at the previous time step comprises: in response to the first node saturation being less than a second threshold, determining the second node saturation according to the first node saturation and the flow sum.

7. A two-dimensional numerical device for simulating seepage softening of discontinuities in rock mass, characterized by, Comprise: a first determining module, configured to determine hydraulic-joint elements in a two-dimensional model region corresponding to a target rock type according to type identifiers of the joint elements in the two-dimensional model region at a current time step; a softening process calculation module, configured to perform softening process calculation on the hydraulic-joint elements to determine contact forces acting on two walls of the hydraulic-joint elements; a seepage calculation module, configured to perform seepage calculation on the hydraulic-joint elements to determine first fluid pressures acting on nodes of the hydraulic-joint elements; a second determining module, configured to determine total equivalent node forces acting on each of the nodes according to the contact forces and the first fluid pressures; wherein the total equivalent node forces are used to update the type identifiers of the joint elements associated with the hydraulic-joint elements; wherein the contact forces comprise tangential frictional stresses, and the performing softening process calculation on the hydraulic-joint elements to determine the contact forces acting on the two walls of the hydraulic-joint elements comprises: obtaining an interface softening function and a friction angle decay function corresponding to the target rock type; wherein the interface softening function is a decay function of a parameter used to measure wall surface strength of a discontinuous surface with immersion time, and the friction angle decay function is a decay function of a friction angle with immersion time; wherein the friction angle comprises a basic friction angle; correcting the basic friction angle according to the interface softening function to obtain a corrected basic friction angle; correcting a wall surface strength parameter according to the friction angle decay function to obtain a corrected wall surface strength parameter; determining a corrected peak shear strength according to the corrected basic friction angle and the corrected wall surface strength parameter; determining the tangential frictional stresses according to the corrected peak shear strength.

8. An electronic device, comprising: Comprise: a processor, and a memory in communication connection with the processor; the memory stores computer execution instructions; the processor executes the computer execution instructions stored in the memory to implement the method according to any one of claims 1-6.

9. A computer readable storage medium, characterized in that, The computer readable storage medium stores computer-executable instructions, which, when executed by a processor, implement the method according to any one of claims 1-6.

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