Roadway grouting optimal design method

Abstract

The invention discloses an optimal design method for roadway grouting, which comprises the following steps of: establishing a roadway initial model according to the size of a roadway on an engineering site, then determining a grouting area according to a grouting length list, then carrying out numerical simulation calculation, and obtaining the convergence amount of a top plate and a bottom plate and the convergence amount of two sides of the roadway through the numerical simulation calculation; when the top and bottom plate convergence amount and the two-side convergence amount are all smaller than 0.2 m, the unit volume of the grouting area at the moment is the target function value corresponding to the group of grouting length parameter lists, and when the top and bottom plate convergence amount and the two-side convergence amount are all larger than 0.2 m, the target function value corresponding to the group of parameters is infinite. In order to obtain the optimal grouting length parameter list, a method of combining a doliolaria optimization algorithm and FLAC3D numerical simulation calculation is adopted to obtain the optimal grouting length parameter list and a grouting area. According to the method, blindness of traditional roadway grouting can be overcome, economic unreasonability caused by excessive grouting is avoided, optimization of the grouting area is achieved, the optimal grouting range is obtained, manual experience does not need to be relied on, and human subjectivity is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction, and in particular to an optimal design method for tunnel grouting. Background Art

[0002] Grouting helps to strengthen the strength and integrity of surrounding rock and improve the stability of tunnel surrounding rock, and is a common means of supporting tunnels. At present, the approximate grouting range for surrounding rock tunnels is generally determined based on experience or rough estimation. In addition, in order to ensure the stability of the tunnel, excessive grouting is common in engineering, which is economically unreasonable. Therefore, under the conditions of determining the stability of the tunnel or allowing deformation, the use of the minimum grouting amount is the focus of tunnel support. In view of the large human subjectivity in the current tunnel grouting support, the lack of scientificity in the determination of grouting schemes, and the widespread existence of excessive grouting, the present invention combines the salp optimization algorithm with the FLAC3D numerical simulation calculation, and determines the optimal grouting orientation parameters through iterative optimization of the optimization algorithm and numerical simulation calculation, thereby determining the optimal grouting range. The present invention can determine the optimal grouting design scheme relatively quickly, has low requirements on the experimenter, and can be applied to the field of tunnel grouting support. Summary of the invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide an optimal design method for tunnel grouting that can provide a better grouting range.

[0004] The technical solution provided by the present invention is as follows:

[0005] An optimal design method for tunnel grouting, comprising:

[0006] The optimal value of the grouting length list parameter is obtained by using the salp optimization algorithm. The grouting length list parameter includes the grouting length corresponding to multiple fixed angle values. The optimal value minimizes the unit volume of the grouting area under the condition that the distance between the top and bottom plates of the roadway and the distance between the two sides are less than 0.2m.

[0007] The unit volume of the grouting area is obtained by using FLAC3D software, including: determining the tunnel grouting area according to the grouting length list parameters; and obtaining the unit volume of the grouting area according to the tunnel grouting area.

[0008] Wherein, determining the tunnel grouting area according to the grouting length list parameters includes:

[0009] The tunnel width and height are determined according to the tunnel cross-sectional dimensions, half of the tunnel model is selected as the research object, the center position of the tunnel floor is selected as the origin O of the coordinate system, and the FLAC3D numerical simulation calculation model is established based on half of the tunnel model;

[0010] The grouting length parameter list is based on the tunnel model. 20 angle values ​​(including -90° and 90°) are evenly selected from -90° to 90°. The grouting length extends outward from the coordinate origin O. When the grouting length value is L, the distance from this point to the coordinate origin is L. For 20 angle values ​​(α1, α2, α3, ..., α 20 ) respectively select the corresponding length value (L1, L2, L3, ..., L 20 ), (α1,α2,α3,......,α 20 ) and (L1,L2,L3,......,L 20 ) is a one-to-one relationship, where (α1, α2, α3, ..., α 20 ) is a fixed value, α1 is -90°, α 20 is 90°;

[0011] Based on the FLAC3D numerical simulation calculation model, the coordinates of each unit body in the calculation model are obtained, and the angle between the unit body and the positive x axis is determined:

[0012]

[0013] α is the angle between the unit body and the positive axis of the x-circle, zx is the x-direction coordinate value of the unit body, zy is the y-coordinate value of the unit body, and then determine the range of the unit body angle α in the angle list (α1, α2, α3, ..., α 20 ):

[0014] α i ≤α<α i+1 (2)

[0015] Where i is the subscript value, and its value range is 1, 2, 3, ..., 19. Calculate its angle subscript value i to determine the grouting length range corresponding to the unit body:

[0016] L i ≤L<L i+1 (3)

[0017] According to the length unit range, determine the specific grouting length of the unit:

[0018]

[0019] When the distance from the coordinates of the point (zx, zy) to the origin of the coordinate system is less than the grouting length of the unit body:

[0020]

[0021] Then the unit body is a grouting unit body. According to the grouting length list (L1, L2, L3, ..., L 20 ), all the units in the FLAC3D model are identified in turn using the above method to determine the grouting area.

[0022] Among them, the use of the salp optimization algorithm to obtain the optimal value of the grouting length list parameter includes: the unit volume of the grouting area obtained according to the grouting area of ​​the tunnel is obtained by using the FISH language built-in in FLAC3D, including: assigning values ​​to the mechanical parameters of the rock and soil body and the grouting area; fixing the tunnel model up and down, left and right, and applying compressive stress to the upper and right ends of the model according to the specific situation, and then starting the numerical simulation calculation. During the numerical simulation calculation, the displacement of the top and bottom plates of the tunnel and the displacement of the two sides are monitored. When the displacement and the displacement of the two sides are less than or equal to 0.2m, the grouting length parameter list value (L1, L2, L3, ..., L 20 ) corresponds to the objective function value of the grouting volume V z .

[0023] Wherein, the method of using the salp optimization algorithm to obtain the optimal value of the grouting length list parameter includes:

[0024] Step 1: Initialize the hyperparameters of the salp optimization algorithm: population size N; maximum number of iterations Max_iter; current number of iterations Now_iter is initially 0; according to the population size N, randomly generate N population individuals, each of which represents a set of grouting length parameter list values ​​(L1, L2, L3, ..., L 20 ), the random initialization process is as follows:

[0025] L i =L min +(L max -L min )×rand (6)

[0026] Where L i represents the i-th grouting length, L max , L min Indicates the maximum and minimum values ​​of the grouting length;

[0027] By adopting the above method, N=50 sets of grouting length parameter list values ​​(L1, L2, L3, ..., L 20 );

[0028] Step 2: For N individuals in the population, that is, N groups of grouting length parameter list values ​​(L1, L2, L3, ..., L 20 ), carry out numerical simulation calculation, and obtain the corresponding grouting unit volume V through numerical simulation calculation zWhen the top and bottom plate movement and the two side movement are both less than 0.2m, the adaptive function value corresponding to the individual is the corresponding grouting unit volume V z , otherwise the fitness value corresponding to the individual is infinite;

[0029] Step 3: Sort the fitness values ​​corresponding to the N groups of populations from small to large, with the smaller fitness values ​​in the front and the larger fitness values ​​in the back; and save the optimal fitness value (minimum value) and the optimal grouting parameter list value (L best-1 ,L best-2 ,L best-3 ,......,L best-20 )

[0030] Step 4: Select the individuals whose fitness ranks in the top 1 / 2, and randomly select formula 7 or formula 8 for update:

[0031] L new-i =L best-i +C1×(C2×(L max -L min )+L min ) (7)

[0032] L new-i =L best-i -C1×(C2×(L max -L min )+L min ) (8)

[0033] Where L new-i represents the newly generated parameter of the i-th grouting length, L best-i Indicates that the i-th grouting length parameter corresponding to the optimal fitness value, L max , L min represents the maximum and minimum values ​​of the grouting length; C2 represents a random parameter between 0 and 1; C1 can be expressed by the following formula:

[0034]

[0035] In the above formula, Now_iter is the current number of iterations, and Max_iter is the total number of iterations;

[0036] Step 5: The remaining 1 / 2 individuals are randomly generated using Formula 6 to replenish the number of individuals until N individuals are reached;

[0037] Step 6: Add 1 to the current number of iterations: Now_iter = Now_iter + 1. If the current number of iterations Now_iter is less than Max_iter, which is 10000, the calculation continues (step 2), otherwise the calculation is terminated (step 7).

[0038] Step 7: Calculation ends;

[0039] Through the above calculation, the final grouting length parameter list (L1, L2, L3, ..., L 20 ).

[0040] Compared with the prior art, the present invention adopts a method combining the salp optimization algorithm with the FLAC3D numerical simulation calculation, which can overcome the blindness of traditional tunnel grouting, avoid excessive grouting and economic irrationality, realize the optimization of the grouting area, and obtain the optimal grouting range without relying on manual experience and avoiding human subjectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a complete schematic diagram of the tunnel cross section in the optimal design method for tunnel grouting according to an embodiment of the present invention.

[0042] Figure 2 for Figure 1 Schematic diagram of half of the tunnel in the middle tunnel section shown.

[0043] Figure 3 for Figure 1 Schematic diagram of the initial model of FLAC3D numerical simulation calculation in the optimal design method of tunnel grouting shown.

[0044] Figure 4 for Figure 1 Schematic diagram of grouting depth in the optimal design method of tunnel grouting is shown.

[0045] Figure 5 for Figure 1 Schematic diagram of the FLAC3D numerical simulation calculation model containing the grouting body in the optimal design method of tunnel grouting shown.

[0046] Figure 6 for Figure 1 Schematic diagram of the optimal grouting area in the optimal design method of tunnel grouting is shown. DETAILED DESCRIPTION

[0047] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0048] An optimal design method for tunnel grouting mainly includes establishing a FLAC3D numerical simulation calculation tunnel grouting model according to a grouting length parameter list and optimizing the grouting length parameter list using a salp optimization algorithm to obtain an optimal grouting length parameter list.

[0049] The FLAC3D numerical simulation model is established according to the grouting length parameter list. The tunnel width and tunnel height are determined according to the tunnel section size. In this example, the tunnel height is H = 3.3m and the tunnel width is L = 5.54m ( Figure 1 ), in order to reduce the amount of calculation of the FLAC3D numerical simulation model, half of the tunnel model was selected as the research object ( Figure 2 ), select the center position of the tunnel floor as the origin of the coordinate system O, based on Figure 2 A FLAC3D numerical simulation calculation model was established for half of the middle tunnel model, with a model length of ML = 22.77m and a model height of MH = 43.3m.

[0050] The grouting length parameter list is based on the tunnel model ( Figure 2 ), 20 angle values ​​(including -90° and 90°) are uniformly selected from -90° to 90°, the grouting length is extended outward from the coordinate origin O, when the grouting length value is L, the distance from this point to the coordinate origin is L, for -90° to 90°, 20 angle values ​​(α1, α2, α3, ..., α 20 ) respectively select the corresponding length value (L1, L2, L3, ..., L 20 ), (α1,α2,α3,......,α 20 ) and (L1,L2,L3,......,L 20 ) is a one-to-one relationship, where (α1, α2, α3, ..., α 20 ) is a fixed value, α1 is -90°, α 20 is 90°.

[0051] based on Figure 3 The FLAC3D numerical simulation calculation model in the calculation model is used to obtain the coordinates of each unit body in the calculation model and determine the angle between the unit body and the positive x axis:

[0052]

[0053] α is the angle between the unit body and the positive axis of the x-circle, zx is the x-direction coordinate value of the unit body, zy is the y-coordinate value of the unit body, and then determine the range of the unit body angle α in the angle list (α1, α2, α3, ..., α 20 ):

[0054] α i ≤α<α i+1 (2)

[0055] Where i is the subscript value, and its value range is 1, 2, 3, ..., 19. Calculate its angle subscript value i to determine the grouting length range corresponding to the unit body:

[0056] L i ≤L<L i+1 (3)

[0057] According to the length unit range, determine the specific grouting length of the unit:

[0058]

[0059] When the distance from the coordinates of the point (zx, zy) to the origin of the coordinate system is less than the grouting length of the unit body:

[0060]

[0061] Then the unit body is a grouting unit body, according to Figure 4 List of grouting lengths (L1, L2, L3, ..., L 20 ), use the above method to Figure 3 All the units in the grouting area are identified in turn, such as Figure 5 , Figure 5 The medium-light area is the grouting area. The built-in FISH language in FLAC3D is used to calculate the unit volume V of the grouting area. z .

[0062] Then the mechanical parameters of the rock and soil mass and the grouting area are assigned, where the rock and soil mass parameters and the grouting area mechanical parameters are shown in Table 1.

[0063] Table 1 Mechanical parameters of rock mass and rock mass in grouting area

[0064]

[0065] At the same time, the tunnel model is fixed up and down, left and right, and 5MPa compressive stress is applied to the upper and right ends of the model, and then the numerical simulation calculation is started. During the numerical simulation calculation, the displacement of the tunnel top and bottom plates and the displacement of the two sides are monitored. When the displacement and the displacement of the two sides are less than or equal to 0.2m (it is considered that the deformation of the tunnel is not serious and the grouting scheme is feasible), the grouting length parameter list value (L1, L2, L3, ..., L 20 ) corresponds to the objective function value of the grouting volume V z (The smaller the objective function, the better. The smaller the objective function value, the smaller the surface grouting range, the smaller the grouting engineering volume and cost). Otherwise, the grouting length parameter list value (L1, L2, L3,......, L 20 ) corresponds to an infinite objective function value.

[0066] Therefore, according to a set of grouting length parameter list values, the corresponding objective function value can be determined.

[0067] The salp optimization algorithm is used to optimize the grouting length parameter list. The optimal grouting length parameter list is obtained by combining the salp optimization algorithm with the FLAC3D numerical simulation calculation. Through continuous iterative optimization, the optimal grouting length parameter list value (L1, L2, L3, ..., L 20 ), so that the grouting area is minimized under the premise that the distance between the top and bottom plates of the roadway and the distance between the two sides meet the conditions as much as possible. The specific implementation steps are as follows:

[0068] Step 1: Initialize the hyperparameters of the salp optimization algorithm: the population size N is 100; the maximum number of iterations Max_iter is 10000; the current number of iterations Now_iter is initially 0. According to the population size N, N population individuals are randomly generated, each of which represents a set of grouting length parameter list values ​​(L1, L2, L3, ..., L 20 ), the random initialization process is as follows:

[0069] L i =L min +(L max -L min )×rand(6)

[0070] Where L i represents the i-th grouting length, L max , L min Represents the maximum and minimum values ​​of the grouting length. In this example, the maximum and minimum values ​​of the grouting length are 18m and 2.77m respectively.

[0071] By adopting the above method, N=50 sets of grouting length parameter list values ​​(L1, L2, L3, ..., L 20 ).

[0072] Step 2: For N individuals in the population, that is, N groups of grouting length parameter list values ​​(L1, L2, L3, ..., L 20 ), carry out numerical simulation calculation, and obtain the corresponding grouting unit volume V through numerical simulation calculation z When the top and bottom plate movement and the two side movement are both less than 0.2m, the adaptive function value corresponding to the individual is the corresponding grouting unit volume V z , otherwise the fitness value corresponding to the individual is infinite.

[0073] Step 3: Sort the N groups of populations according to their corresponding fitness values ​​from small to large, with the smaller fitness values ​​in the front and the larger fitness values ​​in the back. And save the optimal fitness value (minimum value) and the optimal grouting parameter list value (L best-1 ,L best-2 ,L best-3,......,L best-20 )

[0074] Step 4: Select the individuals whose fitness ranks in the top 1 / 2, and randomly select formula 7 or formula 8 for update:

[0075] L new-i =L best-i +C1×(C2×(L max -L min )+L min )(7)

[0076] L new-i =L best-i -C1×(C2×(L max -L min )+L min )(8)

[0077] Where L new-i represents the newly generated parameter of the i-th grouting length, L best-i Indicates that the i-th grouting length parameter corresponding to the optimal fitness value, L max , L min Indicates the maximum and minimum values ​​of the grouting length. In this example, the maximum and minimum values ​​of the grouting length are 18m and 2.77m respectively. C2 represents a random parameter between 0 and 1. C1 can be expressed as follows:

[0078]

[0079] In the above formula, Now_iter is the current iteration number, and Max_iter is the total iteration number.

[0080] Step 5: The remaining 1 / 2 individuals are randomly generated using Formula 6 to replenish the number of individuals until there are N individuals.

[0081] Step 6: The current number of iterations is increased by 1: Now_iter=Now_iter+1. If the current number of iterations Now_iter is less than Max_iter, which is 10000, the calculation continues (step 2), otherwise the calculation is terminated (step 7).

[0082] Step 7: Calculation ends.

[0083] Through the above calculation, the final grouting length parameter list (L1, L2, L3, ..., L 20 ) is (4.47, 3.09, 6.73, 7.99, 8.53, 3.72, 7.66, 9.03, 4.09, 8.42, 4.10, 4.22, 4.66, 7.37, 8.36, 5.32, 9.89, 4.08, 4.74, 5.47), and the grouting area is as follows Figure 6 At this time, the top and bottom plates are moved as close as possible by 0.19m, and the two sides are moved closer by 0.019m, which meets the engineering requirements.

Claims

1. An optimal design method for tunnel grouting, characterized in that: include: The optimal value of the grouting length list parameter is obtained by using the salp optimization algorithm. The grouting length list parameter includes the grouting length corresponding to multiple fixed angle values. The optimal value minimizes the unit volume of the grouting area under the condition that the distance between the top and bottom plates of the roadway and the distance between the two sides are less than 0.2m. The unit volume of the grouting area is obtained by using FLAC3D software, including: determining the grouting area of ​​the roadway according to the grouting length list parameters; The unit volume of the grouting area is obtained according to the grouting area of ​​the tunnel.

2. The optimal design method for tunnel grouting according to claim 1, characterized in that: Determining the tunnel grouting area according to the grouting length list parameters includes: The tunnel width and height are determined according to the tunnel cross-sectional dimensions, half of the tunnel model is selected as the research object, the center position of the tunnel floor is selected as the origin O of the coordinate system, and the FLAC3D numerical simulation calculation model is established based on half of the tunnel model; The grouting length parameter list is based on the tunnel model. 20 angle values ​​(including -90° and 90°) are evenly selected from -90° to 90°. The grouting length extends outward from the coordinate origin O. When the grouting length value is L, the distance from this point to the coordinate origin is L. For 20 angle values ​​(α1, α2, α3, ..., α 20 ) respectively select the corresponding length value (L1, L2, L3, ..., L 20 ), (α1,α2,α3,......,α 20 ) and (L1,L2,L3,......,L 20 ) is a one-to-one relationship, where (α1, α2, α3, ..., α 20 ) is a fixed value, α1 is -90°, α 20 is 90°; Based on the FLAC3D numerical simulation calculation model, the coordinates of each unit body in the calculation model are obtained, and the angle between the unit body and the positive x axis is determined: α is the angle between the unit body and the positive axis of the x-circle, zx is the x-direction coordinate value of the unit body, zy is the y-coordinate value of the unit body, and then determine the range of the unit body angle α in the angle list (α1, α2, α3, ..., α 20 ): α i ≤α＜α i+1 (2) Where i is the subscript value, and its value range is 1, 2, 3, ..., 19. Calculate its angle subscript value i to determine the grouting length range corresponding to the unit body: L i ≤L<L i+1 (3) According to the length unit range, determine the specific grouting length of the unit: When the distance from the coordinates of the point (zx, zy) to the origin of the coordinate system is less than the grouting length of the unit body: Then the unit body is a grouting unit body. According to the grouting length list (L1, L2, L3, ..., L 20 ), all the units in the FLAC3D model are identified in turn using the above method to determine the grouting area.

3. The optimal design method for tunnel grouting according to claim 2, characterized in that: The method of using the salp optimization algorithm to obtain the optimal value of the grouting length list parameter includes: the unit volume of the grouting area according to the grouting area of ​​the roadway is obtained by using the FISH language built-in in FLAC3D, including: assigning values ​​to the mechanical parameters of the rock and soil body and the grouting area; fixing the roadway model up, down, left, and right at the same time, applying compressive stress to the upper end and right end of the model according to the specific situation, and then starting the numerical simulation calculation. During the numerical simulation calculation, the displacement of the roadway top and bottom plates and the displacement of the two sides are monitored. When the displacement and the displacement of the two sides are both less than or equal to 0.2m, the grouting length parameter list value (L1, L2, L3, ..., L 20 ) corresponds to the objective function value of the grouting volume V z .

4. The optimal design method for tunnel grouting according to claim 1, characterized in that: The method of using the salp optimization algorithm to obtain the optimal value of the grouting length list parameter includes: Step 1: Initialize the hyperparameters of the salp optimization algorithm: population size N; maximum number of iterations Max_iter; current number of iterations Now_iter is initially 0; according to the population size N, randomly generate N population individuals, each of which represents a set of grouting length parameter list values ​​(L1, L2, L3, ..., L 20 ), the random initialization process is as follows: L i =L min +(L max -L min )×rand (6) Where L i represents the i-th grouting length, L max , L min Indicates the maximum and minimum values ​​of the grouting length; By adopting the above method, N=50 sets of grouting length parameter list values ​​(L1, L2, L3, ..., L 20 ); Step 2: For N individuals in the population, that is, N groups of grouting length parameter list values ​​(L1, L2, L3, ..., L 20 ), carry out numerical simulation calculation, and obtain the corresponding grouting unit volume V through numerical simulation calculation z When the top and bottom plate movement and the two side movement are both less than 0.2m, the adaptive function value corresponding to the individual is the corresponding grouting unit volume V z , otherwise the fitness value corresponding to the individual is infinite; Step 3: Sort the fitness values ​​corresponding to the N groups of populations from small to large, with the smaller fitness values ​​in the front and the larger fitness values ​​in the back; and save the optimal fitness value (minimum value) and the optimal grouting parameter list value (L best-1 ,L best-2 ,L best-3 ,......,L best-20 ) Step 4: Select the individuals whose fitness ranks in the top 1 / 2, and randomly select formula 7 or formula 8 for update: L new-i =L best-i +C1×(C2×(L max -L min )+L min ) (7) L new-i =L best-i -C1×(C2×(L max -L min )+L min ) (8) Where L new-i represents the newly generated parameter of the i-th grouting length, L best-i Indicates that the i-th grouting length parameter corresponding to the optimal fitness value, L max , L min represents the maximum and minimum values ​​of the grouting length; C2 represents a random parameter between 0 and 1; C1 can be expressed by the following formula: In the above formula, Now_iter is the current number of iterations, and Max_iter is the total number of iterations; Step 5: The remaining 1 / 2 individuals are randomly generated using Formula 6 to replenish the number of individuals until N individuals are reached; Step 6: Add 1 to the current number of iterations: Now_iter = Now_iter + 1. If the current number of iterations Now_iter is less than Max_iter, which is 10000, the calculation continues (step 2), otherwise the calculation is terminated (step 7). Step 7: Calculation ends; Through the above calculation, the final grouting length parameter list (L1, L2, L3, ..., L 20 ).

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