Numerical simulation method and system for high-strength energy-absorbing support system

Abstract

The present invention provides a numerical simulation method and system for a high-strength energy-absorbing support system, which belongs to the technical field of underground engineering support. The scheme divides the tensile test stress process of a high-strength energy-absorbing anchor rod or anchor cable into an elastic stage, a constant resistance stage, a breaking stage and a failure stage, and combines the constitutive equations and mechanical parameters obtained from the anchoring test of the high-strength energy-absorbing anchor rod or anchor cable with a static tensile test. This scheme can effectively solve the problem in the prior art of using structural units to simulate anchor rods and anchor cables, and the rod body will not break even if it reaches the ultimate elongation, and the mechanical properties of the anchor rods and anchor cables cannot be simulated in a refined manner. At the same time, by using solid units to construct a numerical model of high-strength energy-absorbing pillars, it is possible to effectively realize the simulation of large deformation and energy absorption of the pillars, and then realize the numerical simulation of high-strength energy-absorbing support systems under different working conditions, and provide accurate guidance for the support design of high-strength energy-absorbing surrounding rock control systems.

Description

Technical Field

[0001] The invention belongs to the technical field of underground engineering support, and in particular relates to a numerical simulation method and system for a high-strength energy-absorbing support system. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] In view of the difficulty of supporting underground engineering tunnels, high-strength energy-absorbing anchors / anchor cables and high-strength energy-absorbing pillars can resist the internal and external surrounding rocks of the tunnels through support resistance, and at the same time can coordinate the deformation of the surrounding rocks, release part of the energy accumulation in the surrounding rocks, and control the stability of the surrounding rocks. Therefore, exploring the control mechanism of the high-strength energy-absorbing support system with high-strength energy-absorbing anchors / anchor cables and high-strength energy-absorbing pillars as the core is of great significance to the safety control of underground engineering support.

[0004] In order to study the mechanical properties of high-strength energy-absorbing anchors / cables and high-strength energy-absorbing pillars, and explore the control mechanism of high-strength energy-absorbing anchors / cables and high-strength energy-absorbing pillars on tunnel surrounding rock support, it is often carried out by conducting indoor tests of high-strength energy-absorbing anchors / cables and high-strength energy-absorbing pillars and field tests of controlling surrounding rocks. Field tests have the disadvantages of high test costs, long test cycles, and interference with normal construction of mine tunnels. In order to solve the problems existing in field tests, some researchers consider conducting research through numerical simulation methods. Numerical simulation methods are generally recognized by industry insiders because of their low cost, high safety, and the ability to quickly obtain test conclusions.

[0005] However, in traditional numerical calculations, structural units are used to simulate anchor rods and cables. Even if the rod body reaches the ultimate elongation, it will not break, and the mechanical properties of anchor rods and cables cannot be simulated in detail. When structural units are used to simulate high-strength energy-absorbing pillars, only simple assignments are made, and the simulation of large deformation and energy absorption of the pillars is not considered. Moreover, there is a lack of research on the simulation of the support system composed of high-strength energy-absorbing anchor rods / cables and high-strength energy-absorbing pillars, which limits its application in underground engineering support such as mines. Summary of the invention

[0006] The embodiments of the present invention provide a numerical simulation method and system for a high-strength energy-absorbing support system to solve the problem in the prior art that the mechanical properties of high-strength energy-absorbing anchor rods / anchor cables and high-strength energy-absorbing pillars cannot be accurately simulated.

[0007] According to a first aspect of an embodiment of the present invention, a numerical simulation method for a high-strength energy-absorbing support system is provided, comprising:

[0008] Constructing the initial numerical model of high-strength energy-absorbing anchor rod or anchor cable and the initial numerical model of high-strength energy-absorbing support respectively;

[0009] Obtain the constitutive equations and mechanical parameters corresponding to the high-strength energy-absorbing anchor rod or anchor cable and the high-strength energy-absorbing pillar respectively, wherein the constitutive equations and mechanical parameters of the high-strength energy-absorbing anchor rod or anchor cable are obtained through the anchoring test and static tensile test of the high-strength energy-absorbing anchor rod or anchor cable, and the tensile test stress process of the high-strength energy-absorbing anchor rod or anchor cable is divided into an elastic stage, a constant resistance stage, a breaking stage and a failure stage; the constitutive equations and mechanical properties of the high-strength energy-absorbing pillar are obtained through a compression test of the high-strength energy-absorbing pillar, and the compression test stress process of the high-strength energy-absorbing pillar is divided into an elastic stage and a plastic stage;

[0010] Based on the obtained initial numerical model of the high-strength energy-absorbing anchor rod or anchor cable, the initial numerical model of the high-strength energy-absorbing pillar, and the corresponding constitutive equations and mechanical parameters, a numerical model of the high-strength energy-absorbing anchor rod or anchor cable and a numerical model of the high-strength energy-absorbing pillar are obtained;

[0011] By setting the numerical model of high-strength energy-absorbing anchor rods or anchor cables and the numerical model of high-strength energy-absorbing pillars on the pre-constructed surrounding rock model, a numerical model of the high-strength energy-absorbing support system is obtained. Based on the obtained numerical model of the high-strength energy-absorbing support system, numerical simulation of the high-strength energy-absorbing support system is realized.

[0012] Furthermore, the initial numerical model of the high-strength energy-absorbing anchor rod or anchor cable is constructed using structural units, and the initial numerical model of the high-strength energy-absorbing support column is constructed using solid units.

[0013] Furthermore, the constitutive equation and mechanical parameters of the high-strength energy-absorbing anchor rod or anchor cable are specifically expressed as follows:

[0014]

[0015] Among them, δ a is the current elongation, δ t is the elastic limit elongation, δ h is the ultimate elongation in the constant resistance stage, δ d is the elongation at break, A b is the cross-sectional area of ​​the high-strength energy-absorbing anchor, E t is the elastic modulus of high-strength energy-absorbing anchor, E h is the equivalent energy absorption modulus in the constant resistance stage, E d is the equivalent energy absorption modulus at the breaking stage, F z Indicates the axial force exerted on high-strength energy-absorbing anchor rods or anchor cables.

[0016] Furthermore, the constitutive equation and mechanical parameters of the high-strength energy-absorbing support are specifically expressed as follows:

[0017]

[0018] Where c is the bonding strength of the structure surface, is the internal friction angle of the structural surface, F smax is the maximum shear force of the support, A is the contact surface area between the interface and the target surface, and F s represents the shear force acting on the brace element.

[0019] Furthermore, the numerical simulation of the high-strength energy-absorbing support system is specifically as follows:

[0020] Based on the simulation analysis software, the constructed high-strength energy-absorbing support system is simulated and analyzed to determine whether it converges. If it converges, the calculation is terminated; if it does not converge, the parameters of the high-strength energy-absorbing support numerical model or the high-strength energy-absorbing anchor rod or anchor cable numerical model are corrected.

[0021] Furthermore, when there is no convergence, the node normal displacement and shear velocity are calculated, and the preset pillar unit is called; when the pillar shear force of the pillar unit is not less than the maximum shear force of the pillar, the pillar shear force of the pillar unit is assigned the maximum shear force of the pillar; when the pillar shear force of the pillar unit is less than the maximum shear force of the pillar, the parameters of the high-strength energy-absorbing anchor rod or anchor cable are corrected.

[0022] Furthermore, the parameter correction of the high-strength energy-absorbing anchor rod or anchor cable is specifically as follows: calculating the elongation of the anchor rod or anchor cable; if the elongation is in the elastic stage, no parameter correction of the structural unit is performed; if the elongation is in the constant resistance stage, the parameter correction of the structural unit is performed; if the elongation is in the breaking stage, the parameter correction of the structural unit is performed; if the elongation is in the failure stage, the parameter correction of the structural unit is performed.

[0023] Furthermore, if the elongation is in the constant resistance stage, the parameters of the structural unit are modified, specifically:

[0024] Modify the equivalent modulus of the structural unit to:

[0025]

[0026] Modify the axial force of the structural unit to:

[0027] F=E t A b δ t +E h A b (δ a -δ t )

[0028] Among them, F pmax is the limit axial force of the constant resistance module, F e is the yield axial force, A b is the cross-sectional area of ​​the high-strength energy-absorbing anchor, δ t is the elastic limit elongation, δh is the ultimate elongation in the constant resistance stage, δ a is the current elongation, E t is the elastic modulus of high-strength energy-absorbing anchor, E h is the equivalent energy absorption modulus in the constant resistance stage, E is the equivalent modulus, and F represents the axial force exerted on the structural unit.

[0029] Furthermore, if the elongation is at the breaking stage, the parameters of the structural unit are modified, specifically:

[0030] Modify the equivalent energy absorption modulus of the structural unit to:

[0031]

[0032] Modify the axial force of the structural unit to:

[0033] F=E t A b δ t +E h A b (δ h -δ r )-E d A b (δ a -δ h )

[0034] Among them, F pmax is the limit axial force of the constant resistance module, A b is the cross-sectional area of ​​the high-strength energy-absorbing anchor, δ h is the ultimate elongation in the constant resistance stage, δ t is the elastic limit elongation, δ a is the current elongation, E t is the elastic modulus of high-strength energy-absorbing anchor, E h is the equivalent energy absorption modulus in the constant resistance stage, E d is the equivalent energy absorption modulus in the fracture stage, δ d is the elongation at break, E is the equivalent modulus, and F represents the axial force exerted on the structural unit.

[0035] According to a second aspect of an embodiment of the present invention, a numerical simulation system for a high-strength energy-absorbing support system is provided, comprising:

[0036] An initial numerical model construction unit, which is used to respectively construct an initial numerical model of a high-strength energy-absorbing anchor rod or anchor cable and an initial numerical model of a high-strength energy-absorbing pillar;

[0037] A constitutive equation and mechanical parameter acquisition unit, which is used to respectively obtain the constitutive equations and mechanical parameters corresponding to the high-strength energy-absorbing anchor rod or anchor cable and the high-strength energy-absorbing pillar, wherein the constitutive equation and mechanical parameters of the high-strength energy-absorbing anchor rod or anchor cable are obtained through the anchoring test and static tensile test of the high-strength energy-absorbing anchor rod or anchor cable, and the tensile test stress process of the high-strength energy-absorbing anchor rod or anchor cable is divided into an elastic stage, a constant resistance stage, a breaking stage and a failure stage; the constitutive equation and mechanical properties of the high-strength energy-absorbing pillar are obtained through a compression test of the high-strength energy-absorbing pillar, and the compression test stress process of the high-strength energy-absorbing pillar is divided into an elastic stage and a plastic stage;

[0038] A numerical model building unit, which is used to obtain a high-strength energy-absorbing anchor rod or anchor cable numerical model and a high-strength energy-absorbing pillar numerical model based on the obtained high-strength energy-absorbing anchor rod or anchor cable initial numerical model, the high-strength energy-absorbing pillar initial numerical model, and the corresponding constitutive equations and mechanical parameters;

[0039] The numerical simulation unit is used to obtain a numerical model of a high-strength energy-absorbing support system by setting a numerical model of a high-strength energy-absorbing anchor rod or anchor cable and a numerical model of a high-strength energy-absorbing pillar on a pre-constructed surrounding rock model, and to realize numerical simulation of the high-strength energy-absorbing support system based on the obtained numerical model of the high-strength energy-absorbing support system.

[0040] One or more of the above technical solutions have the following beneficial effects:

[0041] (1) The present invention provides a method and system for numerical simulation of a high-strength energy-absorbing support system. The method divides the tensile test stress process of a high-strength energy-absorbing anchor rod or anchor cable into an elastic stage, a constant resistance stage, a breaking stage and a failure stage. By introducing the breaking stage and the failure stage and combining the constitutive equations and mechanical parameters obtained from the anchor test and the static tensile test of the high-strength energy-absorbing anchor rod / anchor cable, the method can effectively solve the problem that the structural unit is used to simulate the anchor rod and anchor cable in the prior art, and the rod body will not break even if the ultimate elongation is reached, and the mechanical properties of the anchor rod and anchor cable cannot be simulated in a refined manner, thereby improving the accuracy of the numerical simulation of the high-strength energy-absorbing anchor rod / anchor cable. At the same time, by using solid units to construct a numerical model of the high-strength energy-absorbing pillar, the large deformation and energy absorption of the pillar can be effectively simulated, thereby realizing the numerical simulation of the high-strength energy-absorbing support system under different working conditions, and providing accurate guidance for the support design of the high-strength energy-absorbing surrounding rock control system.

[0042] (2) The scheme described in the present invention provides different parameter correction strategies according to different working conditions in the numerical simulation of the high-strength energy-absorbing support system, which can adapt to the support design correction of the high-strength energy-absorbing support system under different working conditions.

[0043] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0045] Figure 1 Schematic diagram of a high-strength energy-absorbing anchor rod / anchor cable described in an embodiment of the present invention;

[0046] Figure 2 A schematic diagram of a high-strength energy-absorbing support pillar described in an embodiment of the present invention;

[0047] Figure 3 It is a schematic diagram of the modification process of the high-strength energy-absorbing support system described in an embodiment of the present invention;

[0048] Figure 4 It is a schematic diagram of a numerical model for simulating a high-strength energy-absorbing support system described in an embodiment of the present invention;

[0049] In the figure, 1. anchor rod / anchor cable, 2. unit node, 3. PILE unit, 4. node, 5. axial stiffness of rod body, 6. shear stiffness of anchor, 7. bonding strength of anchor, 8. tunnel roof, 9. inner pillar, 10. outer pillar, 11. tunnel floor, 12. built-in friction beads, 13. sandstone, 14. coal, 15. mudstone, 16. high-strength energy-absorbing anchor rod / anchor cable, 17. high-strength energy-absorbing pillar, 18. tunnel. DETAILED DESCRIPTION

[0050] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0051] It should be noted that the terms used herein are for describing specific embodiments only and are not intended to be limiting of exemplary embodiments according to the present invention.

[0052] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0053] like Figure 1 As shown, an embodiment of the present invention provides a numerical simulation method for a high-strength energy-absorbing support system, comprising:

[0054] Step 1: construct the initial numerical model of high-strength energy-absorbing anchor rod or anchor cable and the initial numerical model of high-strength energy-absorbing pillar respectively;

[0055] In a specific implementation, the initial numerical model of the high-strength energy-absorbing anchor rod or anchor cable is constructed using structural units, and the initial numerical model of the high-strength energy-absorbing support column is constructed using solid units.

[0056] Step 2: respectively obtain the constitutive equations and mechanical parameters corresponding to the high-strength energy-absorbing anchor rod or anchor cable and the high-strength energy-absorbing pillar, wherein the constitutive equation and mechanical parameters of the high-strength energy-absorbing anchor rod or anchor cable are obtained through the anchoring test and static tensile test of the high-strength energy-absorbing anchor rod or anchor cable, and the tensile test stress process of the high-strength energy-absorbing anchor rod or anchor cable is divided into an elastic stage, a constant resistance stage, a breaking stage and a failure stage; the constitutive equation and mechanical properties of the high-strength energy-absorbing pillar are obtained through a compression test of the high-strength energy-absorbing pillar, and the compression test stress process of the high-strength energy-absorbing pillar is divided into an elastic stage and a plastic stage;

[0057] In a specific implementation, the constitutive equation and mechanical parameters of the high-strength energy-absorbing anchor rod or anchor cable are specifically expressed as follows:

[0058]

[0059] Among them, δ a is the current elongation, δ t is the elastic limit elongation, δ h is the ultimate elongation in the constant resistance stage, δ d is the elongation at break, A b is the cross-sectional area of ​​the high-strength energy-absorbing anchor, E t is the elastic modulus of high-strength energy-absorbing anchor, E h is the equivalent energy absorption modulus in the constant resistance stage, E d is the equivalent energy absorption modulus at the breaking stage, F z Indicates the axial force exerted on high-strength energy-absorbing anchor rods or anchor cables.

[0060] The constitutive equation and mechanical parameters of the high-strength energy-absorbing support are specifically expressed as follows:

[0061]

[0062] Where c is the bonding strength of the structure surface, is the internal friction angle of the structural surface, F smax is the maximum shear force of the support, A is the contact surface area between the interface and the target surface, and F s represents the shear force acting on the brace element.

[0063] Specifically, in this embodiment, if Figure 1As shown, a high-strength energy-absorbing anchor rod / anchor cable 1 is constructed by using PILE units 3, including several unit nodes 2. By monitoring the axial stiffness 5 of the rod body, the shear stiffness 6 of the anchor, and the bonding strength 7 of the anchor at the monitoring node 4, the elastic stage, the constant resistance stage, the breaking stage, and the failure stage are divided according to the mechanical properties of the high-strength energy-absorbing anchor rod / anchor cable during the tensile test, and the constitutive equations of each stage are constructed respectively; among them, correction is made according to the comparison result between the elongation of the high-strength energy-absorbing anchor rod / anchor cable and the ultimate elongation of each stage, thereby completing the numerical simulation of the corresponding type of high-strength energy-absorbing anchor rod / anchor cable.

[0064] The constitutive equations of each module include:

[0065] The constitutive equation of the elastic stage unit is: z =E t A b δ t ;

[0066] The unit constitutive equation in the constant resistance stage is: z =E t A b δ t +E h A b (δ a -δ t );

[0067] The unit constitutive equation at the fracture stage is: z =E t A b δ t +E h A b (δ h -δ t )-E d A b (δ a -δ h );

[0068] The unit constitutive equation at the failure stage is: z =0;

[0069] Specifically, it can be expressed as follows:

[0070]

[0071] Where: a is the current elongation, δ t is the elastic limit elongation, δ h is the ultimate elongation in the constant resistance stage, δ d is the elongation at break, A b is the cross-sectional area of ​​the high-strength energy-absorbing anchor, E tis the elastic modulus of high-strength energy-absorbing anchor, E h is the equivalent energy absorption modulus in the constant resistance stage, F pmax is the limit axial force in the constant resistance stage, F e is the yield axial force, E d is the equivalent energy absorption modulus in the breaking stage, F z Indicates the axial force exerted on high-strength energy-absorbing anchor rods or anchor cables.

[0072] In this embodiment, if Figure 2 As shown, the high-strength energy-absorbing support is composed of an inner support 9, an outer support 10 and a built-in friction bead 12. The connection between the inner support 9, the outer support 10 and the friction bead 12 is realized by an interface element. The inner support 9 and the outer support 10 are connected by a sliding component to achieve large deformation, and the energy absorption is achieved by the axial force between the friction bead 12 and the support. Figure 2 The meanings of the relevant parameters in are as follows:

[0073] S represents a slider (i.e. a sliding component), S j represents shear strength, α represents dilatancy angle, T k Indicates tensile strength, k j represents the shear stiffness, k f Represents the normal stiffness.

[0074] According to the mechanical properties during the compression stress process in the high-strength energy-absorbing pillar compression test, it is divided into an elastic stage and a plastic module; according to the calculation steps of FLAC3D, the normal displacement and relative shear velocity of each node of the interface and its action surface will be calculated, and then substituted into the mechanical elements to calculate the normal and tangential contact forces.

[0075] Normal contact force: Among them, t+Δt is the relative displacement, k f is the normal stiffness of the contact surface element, l f is the relative displacement between the nodes on the contact surface and the target surface, σ f is the additional normal stress acting on the target surface from the nodes on the contact surface, A1 is the contact surface area between the interface and the target surface;

[0076] Tangential contact force: Among them, k j is the shear stiffness of the contact surface element, is the relative shear displacement increment, σ j is the additional tangential stress acting on the target surface from the nodes on the contact surface;

[0077] When the shear force of the high-strength energy-absorbing support is less than the maximum shear force, it indicates that it is in the elastic stage;

[0078] When the shear force of the high-strength energy-absorbing support is greater than the maximum shear force, it indicates that it is in the plastic module, and the support shear force is F smax .

[0079] The maximum shear force of the support is Where c is the bonding strength of the structure surface, is the internal friction angle of the structural surface;

[0080] Step 3: Based on the obtained initial numerical model of the high-strength energy-absorbing anchor or anchor cable, the initial numerical model of the high-strength energy-absorbing pillar, and the corresponding constitutive equations and mechanical parameters, a numerical model of the high-strength energy-absorbing anchor or anchor cable and a numerical model of the high-strength energy-absorbing pillar are obtained;

[0081] Step 4: By setting the numerical model of high-strength energy-absorbing anchor rods or anchor cables and the numerical model of high-strength energy-absorbing pillars on the pre-constructed surrounding rock model, a numerical model of the high-strength energy-absorbing support system is obtained. Based on the obtained numerical model of the high-strength energy-absorbing support system, a numerical simulation of the high-strength energy-absorbing support system is realized.

[0082] In a specific implementation, the numerical simulation of the high-strength energy-absorbing support system is specifically as follows:

[0083] Based on the simulation analysis software, the constructed high-strength energy-absorbing support system is simulated and analyzed to determine whether it converges. If it converges, the calculation is terminated; if it does not converge, the parameters of the high-strength energy-absorbing support numerical model or the high-strength energy-absorbing anchor rod or anchor cable numerical model are corrected.

[0084] When there is no convergence, the node normal displacement and shear velocity are calculated, and the preset pillar unit is called; when the pillar shear force of the pillar unit is not less than the maximum pillar shear force, the pillar shear force of the pillar unit is assigned the maximum pillar shear force; when the pillar shear force of the pillar unit is less than the maximum pillar shear force, the parameters of the high-strength energy-absorbing anchor rod or anchor cable are corrected.

[0085] The parameter correction of the high-strength energy-absorbing anchor rod or anchor cable is specifically as follows: calculating the elongation of the anchor rod or anchor cable; if the elongation is in the elastic stage, no parameter correction of the structural unit is performed; if the elongation is in the constant resistance stage, the parameter correction of the structural unit is performed; if the elongation is in the breaking stage, the parameter correction of the structural unit is performed; if the elongation is in the failure stage, the parameter correction of the structural unit is performed.

[0086] Specifically, in the numerical simulation process of the high-strength energy-absorbing support system, the following Figure 3 The modification process of the high-strength energy-absorbing support system shown in the figure includes:

[0087] (1) Main program operation:

[0088] The main program operates, before each step of operation, first determine whether the calculation has converged, if it has converged, the calculation ends; if the calculation has not converged, enter the high-strength energy-absorbing pillar numerical module.

[0089] The main program operation specifically executes the following processing process: when the program starts, the PILE model parameters are input, the pillars and other model parameters are input, and the main program operation begins. Before each step of the operation, it is first determined whether the calculation has converged. If it has converged, the calculation ends; if the calculation has not converged, the high-strength energy-absorbing pillar numerical module is entered.

[0090] Since the implementation of the main program in the simulation analysis software can be compiled according to actual needs by those skilled in the art, the details of the main program will not be repeated here.

[0091] (2) High-strength energy-absorbing support numerical module:

[0092] Calculate the node normal displacement and shear velocity, and the shear force F on the support element s Make judgments;

[0093] When F s ≥F smax When , it means that the pillars will slip and are in the shaping stage. At this time, let r s =F smax , then exit the high-strength energy-absorbing support numerical module and return to the main program operation;

[0094] When F s <F smax When , it means that slippage will occur between the pillars and it is in the elastic stage, and then enters the high-strength energy-absorbing anchor rod / anchor cable numerical module;

[0095] (3) High-strength energy-absorbing anchor rod / anchor cable numerical module:

[0096] Read the length of the anchor rod / anchor cable PILE unit, i is the number of the different PILE units that make up the anchor rod / anchor cable, i = 1, ..., n, n is the total number of units; calculate the elongation

[0097] Among them, Δl bi is the extension length of the anchor rod / cable, l bi is the total length of the anchor rod / cable;

[0098] bi specifically refers to the number of PILE units that make up the anchor rod / cable.

[0099] When δ a <δ t When , it enters the elastic stage and does not make PILE parameter correction;

[0100] When δ t ≤δa <δ h When the constant resistance stage is entered, the PILE parameters are corrected, and E=E h , F=F h ;

[0101] When δ h ≤δ a <δ d When the breaking stage is reached, the PILE parameters are corrected, and E=E d , F=F d ;

[0102] When δ a ≥δ d When , it enters the breaking stage and performs PILE parameter correction, setting E=0, F=0.

[0103] Among them, E h 、E d 、F h 、F d They are:

[0104]

[0105] F h =E t A b δ t +E h A b (δ a -δ t )

[0106] F d =E t A b δ t +E h A b (δ h -δ t )-E d A b (δ a -δ h )

[0107] Among them, F pmax is the limit axial force in the constant resistance stage, F e is the yield axial force, E d is the equivalent energy absorption modulus in the breaking stage.

[0108] In this embodiment, the tunnel 18 is established using entity units, the high-strength energy-absorbing anchor rods / anchor cables 16 are established using structural units, and the high-strength energy-absorbing anchor rods / anchor cables 16 are installed on the top and both sides of the tunnel 18 using a node-to-zone connection method; the high-strength energy-absorbing pillars 17 are established using entity units, and the high-strength energy-absorbing pillars 17 are installed between the top and bottom plates of the tunnel 18 (i.e., the tunnel top plate 8 and the tunnel bottom plate 11) using a zone-to-zone connection method; thus, the following is established: Figure 4 The numerical model of the high-strength energy-absorbing support system is shown, in which the tunnel is located in a coal 14 layer between two different sandstones 13 and mudstones 15.

[0109] In this way, through the above-mentioned strategy, the scheme divides the tensile test stress process of the high-strength energy-absorbing anchor rod or anchor cable into an elastic stage, a constant resistance stage, a breaking stage and a failure stage. By introducing the breaking stage and the failure stage, combined with the constitutive equations and mechanical parameters obtained from the high-strength energy-absorbing anchor rod / anchor cable anchoring test and the static tensile test, it can effectively solve the problem that the structural units are used to simulate anchor rods and anchor cables in the prior art, and the rod body will not break even if it reaches the ultimate elongation, and the mechanical properties of the anchor rods and anchor cables cannot be simulated in a refined manner, thereby improving the accuracy of the numerical simulation of the high-strength energy-absorbing anchor rod / anchor cable; at the same time, by using solid units to construct a numerical model of the high-strength energy-absorbing pillar, it is possible to effectively realize the simulation of the large deformation and energy absorption of the pillar, and then realize the numerical simulation of the high-strength energy-absorbing support system under different working conditions, and provide accurate guidance for the support design of the high-strength energy-absorbing surrounding rock control system.

[0110] In one or more embodiments, a high-strength energy-absorbing support system numerical simulation system is provided corresponding to the above-mentioned high-strength energy-absorbing support system numerical simulation method, including:

[0111] An initial numerical model construction unit, which is used to respectively construct an initial numerical model of a high-strength energy-absorbing anchor rod or anchor cable and an initial numerical model of a high-strength energy-absorbing pillar;

[0112] A constitutive equation and mechanical parameter acquisition unit, which is used to respectively obtain the constitutive equations and mechanical parameters corresponding to the high-strength energy-absorbing anchor rod or anchor cable and the high-strength energy-absorbing pillar, wherein the constitutive equation and mechanical parameters of the high-strength energy-absorbing anchor rod or anchor cable are obtained through the anchoring test and static tensile test of the high-strength energy-absorbing anchor rod or anchor cable, and the tensile test stress process of the high-strength energy-absorbing anchor rod or anchor cable is divided into an elastic stage, a constant resistance stage, a breaking stage and a failure stage; the constitutive equation and mechanical properties of the high-strength energy-absorbing pillar are obtained through a compression test of the high-strength energy-absorbing pillar, and the compression test stress process of the high-strength energy-absorbing pillar is divided into an elastic stage and a plastic stage;

[0113] A numerical model building unit, which is used to obtain a high-strength energy-absorbing anchor rod or anchor cable numerical model and a high-strength energy-absorbing pillar numerical model based on the obtained high-strength energy-absorbing anchor rod or anchor cable initial numerical model, the high-strength energy-absorbing pillar initial numerical model, and the corresponding constitutive equations and mechanical parameters;

[0114] The numerical simulation unit is used to obtain a numerical model of a high-strength energy-absorbing support system by setting a numerical model of a high-strength energy-absorbing anchor rod or anchor cable and a numerical model of a high-strength energy-absorbing pillar on a pre-constructed surrounding rock model, and to realize numerical simulation of the high-strength energy-absorbing support system based on the obtained numerical model of the high-strength energy-absorbing support system.

[0115] It can be understood that the system described in this embodiment corresponds one-to-one to the method in the above embodiment, and its technical details have been described in detail in the first embodiment, so they will not be repeated here.

Claims

1. A numerical simulation method for a high-strength energy-absorbing support system, characterized in that: include: The initial numerical model of high-strength energy-absorbing anchor rods or anchor cables and the initial numerical model of high-strength energy-absorbing pillars are constructed respectively. Obtain the constitutive equations and mechanical parameters corresponding to the high-strength energy-absorbing anchor rod or anchor cable and the high-strength energy-absorbing pillar respectively, wherein the constitutive equations and mechanical parameters of the high-strength energy-absorbing anchor rod or anchor cable are obtained through the anchoring test and static tensile test of the high-strength energy-absorbing anchor rod or anchor cable, and the tensile test stress process of the high-strength energy-absorbing anchor rod or anchor cable is divided into an elastic stage, a constant resistance stage, a breaking stage and a failure stage; the constitutive equations and mechanical properties of the high-strength energy-absorbing pillar are obtained through a compression test of the high-strength energy-absorbing pillar, and the compression test stress process of the high-strength energy-absorbing pillar is divided into an elastic stage and a plastic stage; Based on the obtained initial numerical model of the high-strength energy-absorbing anchor rod or anchor cable, the initial numerical model of the high-strength energy-absorbing pillar, and the corresponding constitutive equations and mechanical parameters, a numerical model of the high-strength energy-absorbing anchor rod or anchor cable and a numerical model of the high-strength energy-absorbing pillar are obtained; By setting the numerical model of high-strength energy-absorbing anchor rods or anchor cables and the numerical model of high-strength energy-absorbing pillars on the pre-constructed surrounding rock model, a numerical model of a high-strength energy-absorbing support system is obtained, and based on the obtained numerical model of the high-strength energy-absorbing support system, a numerical simulation of the high-strength energy-absorbing support system is realized; The constitutive equation and mechanical parameters of the high-strength energy-absorbing support are specifically expressed as follows: Among them, t+Δt is the relative displacement, k f is the normal stiffness of the contact surface element, l f is the relative displacement between the nodes on the contact surface and the target surface, σ f is the additional normal stress acting on the target surface from the nodes on the contact surface, A1 is the contact surface area between the interface and the target surface, k j is the shear stiffness of the contact surface element, is the relative shear displacement increment, σ j is the additional tangential stress acting on the target surface from the nodes on the contact surface; When there is no convergence, the node normal displacement and shear velocity are calculated, and the preset pillar unit is called; when the pillar shear force of the pillar unit is not less than the maximum pillar shear force, the pillar shear force of the pillar unit is assigned the maximum pillar shear force; when the pillar shear force of the pillar unit is less than the maximum pillar shear force, the parameters of the high-strength energy-absorbing anchor rod or anchor cable are corrected.

2. The numerical simulation method of the high-strength energy-absorbing support system according to claim 1 is characterized in that: The initial numerical model of the high-strength energy-absorbing anchor rod or anchor cable is constructed using structural units, and the initial numerical model of the high-strength energy-absorbing support column is constructed using solid units.

3. The numerical simulation method of the high-strength energy-absorbing support system according to claim 1 is characterized in that: The constitutive equation and mechanical parameters of the high-strength energy-absorbing anchor rod or anchor cable are specifically expressed as follows: Among them, δ a is the current elongation, δ t is the elastic limit elongation, δ h is the ultimate elongation in the constant resistance stage, δ d is the elongation at break, A b is the cross-sectional area of ​​the high-strength energy-absorbing anchor, E t is the elastic modulus of high-strength energy-absorbing anchor, E h is the equivalent energy absorption modulus in the constant resistance stage, E d is the equivalent energy absorption modulus at the breaking stage, F z Indicates the axial force exerted on high-strength energy-absorbing anchor rods or anchor cables.

4. The numerical simulation method of the high-strength energy-absorbing support system according to claim 1 is characterized in that: The numerical simulation of the high-strength energy-absorbing support system is specifically as follows: Based on the simulation analysis software, the constructed high-strength energy-absorbing support system is simulated and analyzed to determine whether it converges. If it converges, the calculation is terminated; if it does not converge, the parameters of the high-strength energy-absorbing support numerical model or the high-strength energy-absorbing anchor rod or anchor cable numerical model are corrected.

5. The numerical simulation method of the high-strength energy-absorbing support system according to claim 1 is characterized in that: The parameter correction of the high-strength energy-absorbing anchor rod or anchor cable is specifically as follows: calculating the elongation of the anchor rod or anchor cable; if the elongation is in the elastic stage, no parameter correction of the structural unit is performed; if the elongation is in the constant resistance stage, the parameter correction of the structural unit is performed; if the elongation is in the breaking stage, the parameter correction of the structural unit is performed; if the elongation is in the failure stage, the parameter correction of the structural unit is performed.

6. The numerical simulation method of the high-strength energy-absorbing support system according to claim 5 is characterized in that: If the elongation is in the constant resistance stage, the parameters of the structural unit are modified, specifically: Modify the equivalent modulus of the structural unit to: Modify the axial force of the structural unit to: F=E t A b d t +E h A b (d a -d t ) Among them, F pmax is the limit axial force of the constant resistance module, F e is the yield axial force, A b is the cross-sectional area of ​​the high-strength energy-absorbing anchor, δ t is the elastic limit elongation, δ h is the ultimate elongation in the constant resistance stage, δ a is the current elongation, E t is the elastic modulus of high-strength energy-absorbing anchor, E h is the equivalent energy absorption modulus in the constant resistance stage, E is the equivalent modulus, and F represents the axial force exerted on the structural unit.

7. The numerical simulation method of the high-strength energy-absorbing support system according to claim 5 is characterized in that: If the elongation is at the breaking stage, the parameters of the structural unit are modified, specifically: Modify the equivalent energy absorption modulus of the structural unit to: Modify the axial force of the structural unit to: F=E t A b d t +E h A b (d h -d t )-E d A b (d a -d h ) Among them, F pmax is the limit axial force of the constant resistance module, A b is the cross-sectional area of ​​the high-strength energy-absorbing anchor, δ h is the ultimate elongation in the constant resistance stage, δ t is the elastic limit elongation, δ a is the current elongation, E t is the elastic modulus of high-strength energy-absorbing anchor, E h is the equivalent energy absorption modulus in the constant resistance stage, E d is the equivalent energy absorption modulus in the fracture stage, δ d is the elongation at break, E is the equivalent modulus, and F represents the axial force exerted on the structural unit.

8. High-strength energy-absorbing support system numerical simulation system, characterized by: include: The initial numerical model construction unit is used to construct the initial numerical model of the high-strength energy-absorbing anchor rod or anchor cable and the initial numerical model of the high-strength energy-absorbing pillar. A constitutive equation and mechanical parameter acquisition unit, which is used to respectively obtain the constitutive equations and mechanical parameters corresponding to the high-strength energy-absorbing anchor rod or anchor cable and the high-strength energy-absorbing pillar, wherein the constitutive equation and mechanical parameters of the high-strength energy-absorbing anchor rod or anchor cable are obtained through the anchoring test and static tensile test of the high-strength energy-absorbing anchor rod or anchor cable, and the tensile test stress process of the high-strength energy-absorbing anchor rod or anchor cable is divided into an elastic stage, a constant resistance stage, a breaking stage and a failure stage; the constitutive equation and mechanical properties of the high-strength energy-absorbing pillar are obtained through a compression test of the high-strength energy-absorbing pillar, and the compression test stress process of the high-strength energy-absorbing pillar is divided into an elastic stage and a plastic stage; A numerical model building unit, which is used to obtain a high-strength energy-absorbing anchor rod or anchor cable numerical model and a high-strength energy-absorbing pillar numerical model based on the obtained high-strength energy-absorbing anchor rod or anchor cable initial numerical model, the high-strength energy-absorbing pillar initial numerical model, and the corresponding constitutive equations and mechanical parameters; A numerical simulation unit is used to obtain a numerical model of a high-strength energy-absorbing support system by setting a numerical model of a high-strength energy-absorbing anchor or anchor cable and a numerical model of a high-strength energy-absorbing support pillar on a pre-constructed surrounding rock model, and to realize numerical simulation of the high-strength energy-absorbing support system based on the obtained numerical model of the high-strength energy-absorbing support system; The constitutive equation and mechanical parameters of the high-strength energy-absorbing support are specifically expressed as follows: Among them, t+Δt is the relative displacement, k f is the normal stiffness of the contact surface element, l f is the relative displacement between the nodes on the contact surface and the target surface, σ f is the additional normal stress acting on the target surface from the nodes on the contact surface, A1 is the contact surface area between the interface and the target surface, k j is the shear stiffness of the contact surface element, is the relative shear displacement increment, σ j is the additional tangential stress acting on the target surface from the nodes on the contact surface; When there is no convergence, the node normal displacement and shear velocity are calculated, and the preset pillar unit is called; when the pillar shear force of the pillar unit is not less than the maximum pillar shear force, the pillar shear force of the pillar unit is assigned the maximum pillar shear force; when the pillar shear force of the pillar unit is less than the maximum pillar shear force, the parameters of the high-strength energy-absorbing anchor rod or anchor cable are corrected.

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