Tunnel support optimization method, system, equipment and medium based on nonlinear peridynamics

Abstract

The embodiment of the present invention provides a tunnel support optimization method, system, device and medium based on nonlinear peridynamics, which belongs to the field of structural disaster prevention and mitigation. The method includes: sampling tunnel surrounding rock data and conducting indoor tests to obtain rock stress-strain data; simulating based on the data to obtain a nonlinear constitutive relationship curve of the rock, determining the nonlinear constitutive relationship of the rock, determining the initial parameters of the anchor rod and conducting numerical analysis based on peridynamics, simulating the displacement of the surrounding rock after tunnel excavation unloading and anchor rod insertion, and evaluating the degree of surrounding rock deformation; and optimizing the distribution length and spacing of the anchor rods. By sampling the surrounding rock and conducting indoor tests and conducting numerical analysis based on peridynamics, simulating the displacement of the surrounding rock after tunnel excavation unloading and anchor rod insertion, evaluating the degree of surrounding rock deformation, optimizing the distribution length and spacing of the anchor rods, the accuracy and effectiveness of tunnel support optimization are comprehensively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of structural disaster prevention and mitigation, and in particular to a tunnel support optimization method, system, equipment and medium based on nonlinear near-field dynamics. Background Art

[0002] The stability of rock support is crucial in underground projects, especially in tunnels, underground mines and deep foundation pits. In order to improve the safety of projects, reduce construction costs and extend the service life of structures, rock reinforcement technology has been widely used. Among them, anchor support, as a common and efficient reinforcement method, has been widely used in various underground projects. The function of anchors is to improve the overall stability of the support structure by establishing a firm connection between the rock mass and the surface or structure.

[0003] However, the traditional anchor arrangement method is usually based on empirical design and fails to fully consider factors such as the mechanical properties of the rock mass, geological conditions, and construction environment. With the continuous expansion of underground engineering scale and the increase in engineering complexity, the traditional anchor arrangement method has gradually exposed certain shortcomings in optimizing support effects, reducing construction costs, and improving construction efficiency. Therefore, how to scientifically and reasonably distribute anchors to maximize their reinforcement effect has become an important research topic in the current field of underground engineering support design.

[0004] The optimization problem of anchor distribution is essentially a multi-objective and multi-constrained optimization problem. Traditional design methods usually rely on empirical formulas and field surveys, which cannot fully consider the heterogeneity of rock mass, the interaction between anchors, and the complex changes of external loads. Summary of the invention

[0005] The purpose of the embodiments of the present invention is to provide a tunnel support optimization method, system, equipment and medium based on nonlinear near-field dynamics, which is used to fully or at least partially solve the technical problems existing in the above-mentioned prior art that the heterogeneity of the rock mass, the interaction between anchor rods and the complex changes of external loads cannot be fully considered.

[0006] In order to achieve the above object, an embodiment of the present invention provides a tunnel support optimization method based on nonlinear peridynamics, comprising:

[0007] Sampling tunnel surrounding rock data and conducting indoor tests to obtain rock stress-strain data;

[0008] Simulating based on the stress-strain data of the rock to obtain a nonlinear constitutive relationship curve of the rock and determine the nonlinear constitutive relationship of the rock;

[0009] Determine the initial parameters of the anchor bolts and conduct a numerical analysis based on peridynamics to simulate the displacement of the surrounding rock after tunnel excavation unloading and anchor bolt insertion, and evaluate the degree of surrounding rock deformation;

[0010] Based on the deformation degree of the surrounding rock, the distribution length and spacing of the anchor rods are optimized.

[0011] Optionally, the anchoring depth parameter of the anchor rod is determined according to the following formula:

[0012] ;

[0013] In the formula, is the allowable tensile stress of anchor steel, is the allowable bonding force between the mortar and the anchor, d is the diameter of the anchor, and L1 is the fixing depth of the anchor.

[0014] Optionally, if the anchors are equally spaced, the tunnel excavation unloading is simulated according to the following formula;

[0015] ;

[0016] In the formula, k is the safety factor, i is the spacing between anchor rods, γ is the bulk density of the rock mass, h 0 is the effective length of the anchor rod.

[0017] Alternatively, the surrounding rock stress distribution under the anchor distribution simulated by peridynamics is as follows:

[0018] ;

[0019] ;

[0020] ;

[0021] ;

[0022] In the formula, is the body strain, , K represents the bulk modulus, represents the material point density, and represents the displacement of the material point before and after the action, Alignment of the material point x The force vector state of the material point acting outward, For physical strength, express The volume of a material point, is the initial position vector, is the relative displacement vector, is the weighted volume scalar coefficient, is the partial tensor of the bond extension state, is the influence function, is a peridynamic parameter measured by a simple loading test.

[0023] Optionally, the degree of surrounding rock deformation is evaluated according to the following formula:

[0024] ;

[0025] In the formula, Compute the displacement for a material point, is the allowable displacement of the material point.

[0026] Optionally, optimize the anchor distribution length and spacing according to the following formula:

[0027] ;

[0028] In the formula, L is the design length of the anchor rod, S is the design spacing of anchor rods, [ L ] is the minimum allowable length of the anchor rod, [ S ] is the minimum allowable spacing of anchor rods, G The weighted score for the material point, R n Represents the set of N-dimensional real numbers.

[0029] Optionally, calculate the material point weighted score according to the following formula G :

[0030] ;

[0031] In the formula, Indicates the range importance weight value of surrounding rock. M i It represents the deformation degree of surrounding rock, and N represents the total number of material points.

[0032] On the other hand, the present invention also provides a tunnel support optimization system based on nonlinear peridynamics, comprising:

[0033] Sampling unit, used to sample tunnel surrounding rock data and conduct indoor tests to obtain rock stress-strain data;

[0034] A determination unit is used to perform simulation based on the stress-strain data of the rock to obtain a nonlinear constitutive relationship curve of the rock and determine the nonlinear constitutive relationship of the rock;

[0035] Evaluation unit, used to determine the initial parameters of the anchor bolt and conduct numerical analysis based on peridynamics to simulate the displacement of the surrounding rock after tunnel excavation unloading and anchor bolt insertion, and evaluate the degree of surrounding rock deformation;

[0036] The optimization unit is used to optimize the distribution length and spacing of anchor rods based on the deformation degree of the surrounding rock.

[0037] On the other hand, the present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned tunnel support optimization method based on nonlinear near-field dynamics when executing the program.

[0038] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-mentioned tunnel support optimization method based on nonlinear near-field dynamics.

[0039] Through the above technical scheme, the surrounding rock is sampled and indoor tests are carried out to obtain the stress-strain data of the rock, linear regression is carried out, a data-driven nonlinear constitutive relationship curve is constructed, the initial parameters of the anchor are determined, and numerical analysis based on peridynamics is carried out to simulate the displacement of the surrounding rock after tunnel excavation unloading and anchor insertion, evaluate the deformation degree of the surrounding rock, optimize the distribution length and spacing of the anchor, and obtain the optimal length and distribution spacing of the anchor under a specific surrounding rock structure. This will comprehensively improve the accuracy and effectiveness of tunnel support optimization.

[0040] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings:

[0042] Figure 1 is an implementation flow chart of a tunnel support optimization method based on nonlinear peridynamics provided by an embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram of deformation degree weight division provided by an embodiment of the present invention;

[0044] Figure 3 It is a structural schematic diagram of a tunnel support optimization system based on nonlinear peridynamics provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0046] See also Figure 1 As shown, it is a flowchart of an implementation of a tunnel support optimization method based on nonlinear peridynamics provided by an embodiment of the present invention, which includes the following execution steps:

[0047] Step 100: Sample tunnel surrounding rock data and conduct indoor tests to obtain rock stress-strain data.

[0048] In some embodiments, surrounding rock sampling refers to exploring deeper underground surrounding rocks by core drilling to obtain in-situ rock samples, maintaining the natural structure and composition of the rock, and conducting mechanical property tests. The test refers to uniaxial compression test and tensile test to test the stress-strain relationship of the rock under uniaxial compression conditions, tensile conditions, and complex conditions.

[0049] For example, determine the sampling location: select a representative surrounding rock location according to the geological exploration requirements. Prepare tools: prepare appropriate sampling tools, such as hand hammers, core drills, sampling bags, etc. Rock exposure: clean up the debris around the sampling point to ensure that the rock is exposed intact and not affected by surface weathering. Borehole sampling: use a drill to drill cores and collect core samples. Sample identification: number each sample, record information, and then conduct experimental testing.

[0050] For example, the experiment was carried out: clean the rock test, and make the rock into a rock sample with a diameter of 50mm and a height of 200mm. A 5mm long strain gauge was pasted in the middle of the rock. A universal testing machine was used to carry out uniaxial compression test and tensile test of the surrounding rock sample, with a loading rate of 3mm / min. The strain data was collected by the strain gauge data collector, and the load data was collected by the control computer of the universal testing machine. The load data was divided by the rock area to obtain the stress σ data. Finally, the collection of stress σ and strain ε data points was completed.

[0051] Step 101: Perform simulation based on the stress-strain data of the rock to obtain a nonlinear constitutive relationship curve of the rock and determine the nonlinear constitutive relationship of the rock.

[0052] In some embodiments, in the step of generating a data-driven nonlinear constitutive relationship curve by linear regression: a large amount of experimental data is collected, usually including stress-strain curves under different loading conditions. The experimental data can come from tensile tests and compression tests of materials. Assume that the stress σ ,strain ε The relationship shows a power law model . Use the least squares method to solve the model parameters A and n , the goal of the least squares method is to minimize the sum of squared errors between the predicted values ​​and the actual observed values.

[0053] inA is the proportionality coefficient, n is the strain hardening exponent or stress exponent. The power law model is linearized and the logarithmic treatment of both sides of the equation is performed:

[0054] ;

[0055] can be written as:

[0056] in, , , , .

[0057] Fit the data through linear regression method and solve the parameters c and m , thus obtaining the parameters of the power law model A and n。

[0058] In the linear fitting step: collect experimental data ( σ and ε ), calculate the logarithm of stress and strain, and . Use linear regression to fit , to obtain the fitting result c and m。 The objective function is defined as minimizing the sum of squares of the error between the actual stress and the predicted stress. The objective function is ,in, y i and x i They are i The stress and strain treatment values ​​of the samples. Solving for the parameters, by taking the partial derivatives and setting them to zero, we can get K and n The closed-form solution of can be solved by matrix operation to find the optimal solution:

[0059]

[0060] Optimal regression parameters It can be obtained by least squares solution:

[0061]

[0062] in, is the transpose of the design matrix, is the matrix product, is its inverse matrix.

[0063] For example, from the stress-strain value, logarithmic transformation gives and As shown in Table 1:

[0064] Table 1: Data conversion values ​​corresponding to stress-strain values

[0065]

[0066] After linear regression, we get , converted to a power law model .

[0067] Step 102: Determine the initial parameters of the anchor bolt, and conduct a numerical analysis based on peridynamics to simulate the displacement of the surrounding rock after tunnel excavation unloading and anchor bolt insertion, and evaluate the degree of surrounding rock deformation.

[0068] Specifically, the anchoring depth parameter of the anchor rod is determined according to the following formula:

[0069] ;

[0070] In the formula, The allowable tensile stress of anchor steel, for example, the allowable stress of HRB400 steel bar of national standard is 360MPa. is the allowable bonding strength between mortar and anchor rod. For ordinary cement mortar (such as 1:4, 1:6 cement to sand ratio), its bonding strength is generally between 0.1-0.3 MPa, and fine stone concrete mortar can usually reach 0.3-0.5 MPa. For example, ordinary cement mortar, the bonding strength is 0.2 MPa, d is the diameter of the anchor rod, and L1 is the anchor rod's fixed depth.

[0071] If ,but , in engineering applications, L It should be greater than or equal to 300mm. Based on the suspension theory of anchor rods, the total length of anchor rods should be , L 2 is the exposed length of the anchor rod, which is generally 20 to 50 mm; h 0 is the effective length of the anchor rod.

[0072] Preferably, the effective anchorage length is calculated as follows:

[0073]

[0074] K is the safety factor, ranging from 1.5 to 2, for example, 1.5. B is the tunnel excavation width, for example 5m, f is the rock strength coefficient of the tunnel roof, for example, 3, H is the tunneling height, The roof rock Proctor coefficient is used to measure the strength of the rock. is the internal friction angle of the surrounding rock, h 0 is 1.25m, so we get L =1.25+0.2+0.35=1.80 m, set it as the initial length of the anchor L 0 for subsequent optimization.

[0075] Specifically, if the anchors are distributed at equal intervals, the weight of the surrounding rock mass borne by each anchor is the load it bears, and the tunnel excavation unloading is simulated according to the following formula;

[0076] ;

[0077] In the formula, k is the safety factor, generally taken as 2 to 3, for example, 2. i is the spacing between anchor rods, γ is the bulk density of the rock mass, for example, 2.66 g / cm 3 , then the bulk density is 26600 N / m 3 , h 0 is the effective length of the anchor rod.

[0078] If the tensile stress on the anchor rod is greater than its allowable tensile stress, the anchor rod will be damaged, which can be described by the following formula:

[0079] ;

[0080] That is to say, there is ;

[0081] Anchor length h0, diameter d, spacing i And allowable tensile stress If any two variables are known, the remaining unknowns can be calculated. The initial length of the anchor is determined L 0 and initial spacing value S 0, the calculated anchor spacing is 0.72m, so the initial anchor spacing S 0=0.72 m.

[0082] Specifically, the surrounding rock stress distribution under the anchor distribution simulated by peridynamics is as follows:

[0083] ;

[0084] ;

[0085] ;

[0086] ;

[0087] In the formula, is the body strain, , K represents the bulk modulus, represents the material point density, and represents the displacement of the material point before and after the action, Alignment of the material point x The force vector state of the material point acting outward, For physical strength, express The volume of a material point, is the initial position vector, is the relative displacement vector, is the weighted volume scalar coefficient, is the partial tensor of the bond extension state, is the influence function, is a peridynamic parameter measured by a simple loading test.

[0088] The material points in the excavation area are dormant by using the "life and death material point" technology to generate unbalanced forces to simulate the excavation process. The process includes: to simulate the tunnel excavation process, the material points in the excavation area are set as "life and death material points". If the material point is in the "dead" state, the bond interaction force between the material points in the excavation area and the non-excavation area is cut off. Characterize the excavation process, and its specific expression is:

[0089]

[0090] Will It is multiplied by the constitutive force equation f below to simulate the disappearance of the interaction force, which causes unbalanced forces to be generated at the material points, resulting in force behavior.

[0091] In some embodiments, the peridynamic expression of the rock constitutive relationship under data drive is determined as follows: the unit strain energy of the rock is calculated by the stress-strain relationship determined by data drive: , the calculation expression is .

[0092] In some embodiments, the step of determining the constitutive relationship of the surrounding rock according to the test results includes:

[0093] The force vector state of peridynamics is calculated as:

[0094] ;

[0095] ;

[0096] ;

[0097] in, is the body strain, is the stretch scalar deviator part, K and G are the bulk modulus and shear modulus, and their values ​​can be obtained from the surrounding rock sample test. is the initial relative displacement vector, is the relative displacement vector, For relative displacement When the material point pairs store the unit volume strain energy density, its value is related to the unit strain energy density same.

[0098] The final peridynamic expression of the constitutive force equation is:

[0099]

[0100] ,in It is a scalar valued function with history dependency, taking values ​​of 0 or 1. If it is 1, the characterization bond is intact, and if it is 0, the characterization bond is broken. The specific expression is as follows:

[0101] ;

[0102] Elongation of key s The relative position and relative displacement of the keys n express:

[0103] ;

[0104] The critical elongation is:

[0105] ;

[0106] Micro elastic modulus c The value function of is:

[0107] ;

[0108] in, A is the material point cross-sectional area, E is the elastic modulus of the material. According to the unit strain energy density Derivation The expression of is the initial relative displacement vector, is the relative displacement vector.

[0109] In some embodiments, the step of establishing the strength reduction constitutive relation of the surrounding rock comprises: introducing a reduction coefficient into the constitutive force function λ i, characterizing the influence mechanism of joints and cracks on the interaction forces between microscopic material points.

[0110] The peridynamic constitutive force model of the strength reduction factor is:

[0111]

[0112] in, λ is the strength reduction factor, which ranges from 0 to 1:

[0113]

[0114] In some embodiments, the displacement value of excavation unloading under anchor arrangement is calculated: the static solution step is iteratively calculated to obtain the material point acceleration matrix or velocity matrix The corresponding calculation formula is:

[0115]

[0116]

[0117]

[0118]

[0119] In the formula, is the body strain, , K represents the bulk modulus, represents the material point density, and represents the displacement of the material point before and after the action, Alignment of the material point x The force vector state of the material point acting outward, For physical strength, express The volume of a material point, is the initial position vector, is the relative displacement vector, is the weighted volume scalar coefficient, is the partial tensor of the bond extension state, is the influence function, It is a peridynamic parameter and can be measured by a simple loading test.

[0120] The equation of motion is n The form of a time step is as follows:

[0121]

[0122]

[0123]

[0124] In the formula, and is the force density vector between material points, n The time step is of the form and , Material point i With material point j The initial position vector of n The time step is of the form , Material point i With material point j The relative displacement vector, n The time step is of the form , and Material points i With material point j The weighted volume scalar coefficient of n The time step is of the form and , and Material points i With material point j The weighted volume scalar coefficient of is the volume strain, the material point i and j No. n The volume strain at each time step is expressed as and .

[0125] and

[0126] In the formula, Material point i With material point j The initial position vector of n The time step is of the form , and Material points i With material point j The weighted volume scalar coefficient of n The time step is of the form and , and Material points i With material point j The weighted volume scalar coefficient of is the influence function.

[0127] Volume strain of a material point for:

[0128] and

[0129] In the formula, Material point i With material point j The initial position vector of n The time step is of the form , Material point i With material point j The relative displacement vector, n The time step is of the form , and Material points i With material point j The weighted volume scalar coefficient of and Material points i With material point j The weighted volume scalar coefficient of the material point i and j No. n The volume strain at each time step is expressed as and , is the influence function.

[0130] Determine the material point n After the acceleration of the first time step, the time difference formula for the explicit forward and backward steps can be used to obtain n+ Velocity and displacement for 1 time step.

[0131] No. n+ Velocity of a material point in 1 time step as follows:

[0132]

[0133] In the formula, For the n The material point acceleration at the time step, For the n The material point velocity at the time step, is the time step interval.

[0134] No. n+ The displacement of a material point in 1 time step is as follows:

[0135]

[0136] In the formula, For the n +1 time step material point velocity, For the n The material point displacement in the time step, is the time step interval.

[0137] At the same time, the velocity and displacement of other material points can be obtained, and then the deformation state of the entire calculation area at different time steps can be obtained.

[0138] In some embodiments, the steps of using peridynamic simulation include: discretizing material points, constructing and initializing mechanical information matrices such as material point space coordinate matrix, family matrix, bond cleavage matrix, etc.; applying body force to material points, initial ground stress balance: setting the material in the excavation area from the "living" state to the "dead" state, cutting off the bond interaction force between the material points in the excavation area and the non-excavation area, and using a scalar function Characterize the excavation process, and its specific expression is:

[0139]

[0140] Will Multiply it with the constitutive force equation to simulate the disappearance of the interaction force, which causes the material point to produce an unbalanced force, thereby causing force behavior. Iterate and calculate the acceleration, velocity, and displacement of the material point.

[0141] For example, the calculation area is discretized into a finite number of material points, each of which has a certain spatial coordinate. The material points are arranged at the centroid of the subdomain, and all mechanical behavior information of the subdomain is recorded. By numbering the material points, the spatial coordinate matrix [X] of the material points is obtained, and the material point load matrix [F] and displacement matrix [U] are constructed.

[0142] For example, construct a family matrix: with the near-field range of the initial configuration δ The points in the material point family are taken as material points in the family, and the material point family matrix in the form of constants is constructed. δ The number of rows in the family matrix [N] represents the corresponding core material point number, and the value stored in each row represents the neighbor material point number corresponding to the core material point.

[0143] For example, the bond-breaking matrix within the nonlocal action range of a material point is constructed: a scalar-valued function with history dependence is introduced into the basic equation of peridynamics, using Describing the integrity of the bond enables effective simulation of continuous-discontinuous processes. When , the bond is complete; when When , it means that the bond is broken, and the bond will not be restored after breaking, so the bond breaking matrix is ​​constructed. The number of rows in the matrix represents the corresponding core material point number, and the value stored in each row represents the integrity information of the key between the core material point and its neighboring material points. For the empty matrix positions, 1 needs to be added to achieve effective storage and operation of the matrix.

[0144] In some embodiments, based on the displacement of material points in the calculation results u i , quantitatively evaluate the effect of this anchor spacing and length arrangement. Carry out multi-parameter optimization to obtain the optimal solution of anchor spacing and length when the evaluation score reaches the extreme value.

[0145] Specifically, ensure that all surrounding rock displacements ,in Compute the displacement for a material point, is the allowable displacement of the material point. Calculate the displacement evaluation score for each material point , to assess the degree of deformation. Quantify, divide the range of surrounding rock importance, and assign weight values For example, if the distance to the tunnel is close, the weight value is high. Figure 2 FIG. 1 is a schematic diagram of a deformation degree weight division provided by an embodiment of the present invention. Figure 2 The comparison between 1.0 times the longest anchor length and 1.5 times the longest anchor length is shown in the figure. The following formula can be used to determine the distance from the hole: .

[0146]

[0147] in L max is the longest anchor length.

[0148] Traverse material points and calculate weighted scores G , ,quantitatively evaluate the anchoring scheme, and it can be seen that a high score represents insecurity.

[0149] In addition, the deformation degree of surrounding rock is evaluated according to the following formula:

[0150] ;

[0151] In the formula, Compute the displacement for a material point, is the allowable displacement of the material point.

[0152] In some embodiments, the step of determining the fitting relationship between the evaluation score and multiple parameters comprises:

[0153] assumed GThe polynomial relationship of (L, S) is as follows:

[0154] ;in, G is the target variable; L and S is the independent variable; a 0 , a 1 … a n are the coefficients to be fitted; L m S p etc. are different powers of the polynomial. According to the accuracy, the first five terms can be used, that is, , in order to capture nonlinear relationships while preventing overfitting.

[0155] Given a data point , , And other data:

[0156]

[0157] Fit the regression model using the method of least squares to minimize the sum of squared errors between the predicted and actual values:

[0158]

[0159] in, is the design matrix, which contains all the feature items, is the vector of target variables, i.e. G The actual value of . is the parameter vector to be fitted, including all regression coefficients, and finally obtains the expression of G(L, S).

[0160] Step 103: Optimize the distribution length and spacing of anchor rods based on the degree of deformation of the surrounding rock.

[0161] Specifically, the anchor length L and the distribution spacing S determine the parameters of the optimization problem and initialize the anchor length L 0 and distribution spacing S 0, the objective function and constraints of the optimization problem, the anchor distribution length and spacing are optimized according to the following formula:

[0162] ;

[0163] Where L is the design length of the anchor rod, S is the design spacing of the anchor rod, [ L ] is the minimum allowable length of the anchor rod, [ S] is the minimum allowable spacing of anchor rods, and the corresponding value is given in GB 5007-2011. A large number of numerical simulation tests were carried out and the fitting formula was used to obtain G The relationship between (L, S), G Weighted score for material points, R n In some embodiments, the values ​​of L and S are iteratively optimized using the steepest descent method to obtain a preferred solution for anchor arrangement: To minimize the objective function G, the anchor length is initialized L 0 and distribution spacing S 0:

[0164] Calculate partial derivatives and ;

[0165] Gradient descent updates the parameter term, and the update iteration formula is:

[0166] ;

[0167] ;

[0168] in, η is the learning rate, which controls the amplitude of each update. It can be taken as 0.01 to control the iteration step size. Repeat the iterative update until the parameters converge or the gradient approaches zero, and the optimal anchor arrangement solution is obtained.

[0169] Compared with the traditional theoretical constitutive behavior, the rock constitutive relationship based on data-driven in this application has better accuracy. Based on the nonlinear peridynamic equation and gradient descent optimization method, compared with the simulation of the complex mechanical behavior of rock and the displacement results under the action of anchor rods based on classical methods such as finite element, it can better simulate the fracture and softening process of rock, thereby improving the calculation accuracy.

[0170] In some embodiments, see Figure 3 FIG. 1 is a schematic diagram of a structure of a tunnel support optimization system based on nonlinear peridynamics provided by an embodiment of the present invention, comprising:

[0171] The sampling unit 30 is used to sample tunnel surrounding rock data and conduct indoor tests to obtain rock stress-strain data;

[0172] A determination unit 31 is used to perform simulation based on the stress-strain data of the rock to obtain a nonlinear constitutive relationship curve of the rock, and determine initial parameters of the anchor based on the nonlinear constitutive relationship curve of the rock;

[0173] An evaluation unit 32 is used to carry out numerical analysis based on peridynamics, simulate the displacement of surrounding rock after tunnel excavation unloading and anchor bolt insertion, and evaluate the degree of surrounding rock deformation;

[0174] The optimization unit 33 is used to optimize the distribution length and spacing of anchor rods based on the deformation degree of the surrounding rock.

[0175] The tunnel support optimization system based on nonlinear peridynamics includes a processor and a memory. The sampling unit, determination unit, evaluation unit and optimization unit are all stored in the memory as program units, and the processor executes the program units stored in the memory to realize corresponding functions.

[0176] The processor includes a kernel, which retrieves the corresponding program unit from the memory. One or more kernels can be set, and the fracture and softening process of the rock can be better simulated by adjusting the kernel parameters, thereby improving the calculation accuracy.

[0177] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0178] An embodiment of the present invention provides a storage medium on which a program is stored. When the program is executed by a processor, the tunnel support optimization method based on nonlinear peridynamics is implemented.

[0179] An embodiment of the present invention provides a processor, which is used to run a program, wherein the tunnel support optimization method based on nonlinear peridynamics is executed when the program is running.

[0180] The present application also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialization program having the following method steps: sampling tunnel surrounding rock data and conducting indoor tests to obtain rock stress-strain data; performing simulation based on the rock stress-strain data to obtain a nonlinear constitutive relationship curve of the rock, and determining initial parameters of the anchor rod based on the nonlinear constitutive relationship curve of the rock; conducting numerical analysis based on near-field dynamics to simulate the displacement of the surrounding rock after tunnel excavation unloading and anchor rod insertion, and evaluate the degree of surrounding rock deformation; and optimizing the distribution length and spacing of the anchor rods based on the degree of surrounding rock deformation.

[0181] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0182] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0183] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0184] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0185] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0186] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0187] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0188] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0189] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A tunnel support optimization method based on nonlinear peridynamics, characterized in that: include: Sampling tunnel surrounding rock data and conducting indoor tests to obtain rock stress-strain data; Simulating based on the stress-strain data of the rock to obtain a nonlinear constitutive relationship curve of the rock and determine the nonlinear constitutive relationship of the rock; Determine the initial parameters of the anchor bolts and conduct a peridynamics-based numerical analysis to simulate the displacement of the surrounding rock after tunnel excavation unloading and anchor bolt insertion, and evaluate the degree of surrounding rock deformation; Based on the deformation degree of the surrounding rock, optimizing the distribution length and spacing of the anchor rods; Among them, the anchoring depth parameter of the anchor rod is determined according to the following formula: ； In the formula, is the allowable tensile stress of anchor steel, is the allowable bonding force between the mortar and the anchor, d is the diameter of the anchor, and L1 is the fixing depth of the anchor; If the anchors are distributed at equal intervals, the tunnel excavation unloading is simulated according to the following formula; ； In the formula, k is the safety factor, i is the spacing between anchor rods, γ is the bulk density of the rock mass, h 0 is the effective length of the anchor rod; Among them, the surrounding rock stress distribution method under the anchor distribution using peridynamic simulation is as follows: ； ； ； ； In the formula, is the body strain, , K represents the bulk modulus, represents the material point density, and represents the displacement of the material point before and after the action, Alignment of the material point x The force vector state of the material point acting outward, For physical strength, express The volume of a material point, is the initial position vector, is the relative displacement vector, is the weighted volume scalar coefficient, is the partial tensor of the bond extension state, is the influence function, is the peridynamic parameter, measured by a simple loading test; Among them, the deformation degree of surrounding rock is evaluated according to the following formula: ； In the formula, Compute the displacement for a material point, is the allowable displacement of the material point; Among them, the anchor distribution length and spacing are optimized according to the following formula: ； In the formula, L is the design length of the anchor rod, S is the design spacing of anchor rods, [ L ] is the minimum allowable length of the anchor rod, [ S ] is the minimum allowable spacing of anchor rods, G Weighted score for material points, R n Represents the set of N-dimensional real numbers.

2. The tunnel support optimization method based on nonlinear peridynamics according to claim 1 is characterized in that: The material point weighted calculation score is calculated according to the following formula G : ； In the formula, Indicates the range importance weight value of surrounding rock. M i It represents the deformation degree of surrounding rock, and N represents the total number of material points.

3. A tunnel support optimization system based on nonlinear peridynamics applied to the tunnel support optimization method based on nonlinear peridynamics as claimed in any one of claims 1 to 2, characterized in that: include: Sampling unit, used to sample tunnel surrounding rock data and conduct indoor tests to obtain rock stress-strain data; A determination unit is used to perform simulation based on the stress-strain data of the rock to obtain a nonlinear constitutive relationship curve of the rock and determine the nonlinear constitutive relationship of the rock; Evaluation unit, used to determine the initial parameters of the anchor bolt and conduct numerical analysis based on peridynamics to simulate the displacement of the surrounding rock after tunnel excavation unloading and anchor bolt insertion, and evaluate the degree of surrounding rock deformation; The optimization unit is used to optimize the distribution length and spacing of anchor rods based on the deformation degree of the surrounding rock.

4. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the tunnel support optimization method based on nonlinear near-field dynamics as described in any one of claims 1-2 are implemented.

5. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the tunnel support optimization method based on nonlinear near-field dynamics as described in any one of claims 1-2 are implemented.

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