Shield tunneling machine thrust dynamic distribution method based on segment structure mechanical response

Abstract

The invention provides a shield tunneling machine thrust dynamic distribution method based on pipe piece structure mechanical response, belongs to the technical field of shield tunnel construction, and is used for shield tunneling pushing and splicing synchronous operation. According to the method, a segment structure finite element model is used for obtaining segment structure internal force under initial and filial generation thrust distribution; evaluating the fitness of each group of thrust distribution samples by using a swarm intelligence optimization algorithm model and taking the internal force of the segment structure as an optimization target, judging whether the thrust distribution samples converge or not, and iteratively updating a progeny thrust distribution sample; and the iterated offspring thrust distribution is imported into the finite element model again, and iteration is performed until the thrust distribution meets the convergence criterion. According to the method, the shield thrust is dynamically distributed by taking the internal force of the duct piece as an optimization target, and the problems of cracking, damage and the like of the duct piece structure due to poor thrust possibly caused by thrust distribution without considering the safety of the duct piece structure in the prior art can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of shield tunnel construction, and in particular to a shield machine thrust dynamic distribution method based on the mechanical response of a segment structure under shield pushing and splicing synchronous operation. Background Art

[0002] The intelligent transformation of shield construction technology can effectively deal with the current structural shortage of labor and actively respond to the requirements of high-quality construction, becoming an inevitable trend under the current background. Push-and-splice synchronous operation is an important technical presentation form of intelligent shield advancement. It connects shield excavation and segment assembly in parallel, significantly improving the efficiency of shield construction. It has attracted much attention from the industry in recent years. When assembling segments, the shield machine needs to retract some hydraulic cylinders to make room for segment installation. During this process, the cylinders and segments have no direct contact, so no forward thrust can be generated. The traditional shield method adopts push-and-splice alternating operation, and the cylinders are locked and stopped during segment assembly. When the shield machine pushes and splices synchronously, segment assembly and cylinder jacking operations are carried out in parallel. Except for the retracted cylinders, the remaining cylinders continue to press the formed tunnel segments and push forward, which is easy to form an eccentric advancement state with partial thrust loss. At this time, if there is no effective dynamic redistribution of thrust, the shield will face the risk of eccentric instability, threatening the accuracy of the tunnel axis and construction safety [1,2].

[0003] Chinese patent CN114635698A proposes a method for redistributing missing thrust based on the same block and the same pressure, and distributes the missing thrust to the remaining effective propulsion cylinders based on the principle of linear increase. Chinese patent CN117094253A proposes a cylinder thrust distribution algorithm and system based on thrust uniformity under synchronous pushing and splicing, with the minimum variance of the thrust of each cylinder as the optimization goal, and the cylinder thrust distribution is obtained based on the optimization algorithm. Chinese patent CN116882129A proposes a thrust distribution calculation method for a shield propulsion system under constant / non-constant mechanical constraints, with the minimization of the sum of squares of the thrust increments of the working cylinders as the optimization goal, and the cylinder thrust distribution is also obtained based on the optimization algorithm. The constraints of the above methods all take into account the total thrust size, horizontal moment, vertical moment, and the upper and lower limits of the thrust of a single propulsion cylinder.

[0004] However, the existing methods cannot consider the stress safety of the segment structure when distributing thrust. In the process of traditional shield construction, the segment structure problems caused by poor thrust distribution have been very significant [3,4,5]. In the case of simultaneous thrust distribution, there will also be a large proportion of local thrust loss, which aggravates the degree of poor thrust distribution, will cause a more unfavorable stress state of the segment structure, and even cause structural cracking or damage.

[0005] References:

[0006] [1] Wang Xuyang, Yuan Dajun, Jin Dalong, et al. Calculation method of thrust redistribution considering shield posture in synchronous pushing and assembly[J]. China Journal of Highway and Transport, 2023, 36(06): 157-170.

[0007] [2] Zhu Y, Zhu Y, Chen EJ, et al. Synchronous shield tunnelling technology combining advancement and segment fabrication: Principle, verification and application [J]. Underground Space, 2023, 13: 23-47.

[0008] [3] Zhang Weilie, Yan Qixiang, Zhang Chuan, et al. Cracking characteristics of subway segment lining under the poor thrust of shield jack[J]. Journal of Southwest Jiaotong University, 2023, 58(05): 1073-1082.

[0009] [4] Lu Daiyue, Sun Wenhao, Su Ang, et al. Statistical analysis of segment lining crack damage during shield tunnel construction period [J]. Journal of Railway Engineering Society, 2018, 35(06): 59-66+87.

[0010] [5] Geng Aopeng, Li Xue, Zhou Shunhua, et al. Analysis and prevention of segment damage during construction of large-diameter shield tunnels[J]. Chinese Journal of Underground Space and Engineering, 2022, 18(S1): 326-331. Summary of the invention

[0011] In order to solve the above problems, the present invention provides a method for dynamic distribution of shield machine thrust based on the mechanical response of the segment structure. By jointly iteratively solving finite element calculation and swarm intelligence optimization algorithm, it is possible to dynamically distribute the shield thrust by taking the internal force of the segment as the optimization target. This can solve the problems of cracking and damage of the segment structure caused by poor thrust in the prior art due to the failure to consider the safety of the segment structure during thrust distribution.

[0012] The present invention is implemented by the following scheme: a thrust dynamic distribution method of a shield machine based on the mechanical response of a segment structure, which is used for shield pushing and splicing synchronous operation, and the thrust dynamic distribution method comprises the steps of:

[0013] S1. Establish a finite element model of the segment structure to calculate the internal force of the segment under the thrust of the shield cylinder;

[0014] S2, setting constraints, and generating initial thrust distribution of N groups of shield cylinders (N is a natural number greater than 1) through a constraint optimization algorithm, wherein the constraints include thrust resultant force and thrust point limit that satisfy the mechanical balance of shield motion, thrust upper limit of a single group of shield cylinders, and thrust of shield cylinders in the retraction area is zero;

[0015] S3, importing the generated N groups of initial thrust distribution into the finite element model to obtain N groups of segment internal force calculation results;

[0016] S4, importing the calculation results of the N groups of segment internal forces into the swarm intelligent optimization algorithm model, taking the minimum segment internal force as the optimization target of thrust distribution, and using the constraint conditions set in step S2 to calculate N groups of fitness, and then finding the minimum fitness from the N groups of fitness;

[0017] S5. Determine whether the minimum fitness satisfies the convergence standard according to the convergence criterion:

[0018] If yes, the thrust distribution corresponding to the minimum fitness is taken as the optimal thrust distribution, and step S6 is executed;

[0019] If not, the swarm intelligence optimization algorithm model is used to adjust the N groups of thrust distribution to obtain N groups of offspring thrust distribution, and then steps S3 to S5 are repeated;

[0020] S6. Determine whether the internal force of the segment under the optimal thrust distribution meets the structural stress safety:

[0021] If yes, output the optimal thrust distribution result;

[0022] If not, exit the shield pushing and splicing synchronous operation.

[0023] A further improvement of the present invention is that the expression of the constraint condition set in step S2 includes:

[0024]

[0025] 0≤F 推进i ≤F limit

[0026] F 回缩1 =F 回缩2 =F 回缩3 =... =F 回缩I =0

[0027] Where: E is the total number of effective propulsion cylinders; F 推进i F is the thrust of each group of effective propulsion cylinders; 阻 H is the resistance that the shield needs to overcome in advancing; iV is the horizontal distance from the thrust point of the i-th group of cylinders to the center of the circle O; i is the vertical distance from the thrust point of the i-th group of cylinders to the center of the circle O; (e x ,e y ) is the coordinate of the resultant force point required to control the shield posture, that is, the horizontal eccentricity e of the resultant force x and vertical eccentricity e y ; F limit F is the upper limit of the thrust of a single set of propulsion cylinders; 回缩1 、F 回缩2 、F 回缩3 ,...F 回缩I is the thrust of the cylinder in the retraction area corresponding to the segment to be assembled, both are 0, and I is the number of cylinders in the retraction area corresponding to the segment to be assembled.

[0028] A further improvement of the present invention is that the internal force of the segment includes the segment structure tensile stress σ t-max , the calculation expression for optimizing thrust distribution with the minimum internal force of the segment is:

[0029] f(F 推进1 ,F 推进2 ,F 推进3 ,...,F 推进E )=min(σ t-max )

[0030] Where: f(F 推进1 ,F 推进2 ,F 推进3 ,...,F 推进E ) is the optimization objective function; E is the total number of effective propulsion cylinders.

[0031] A further improvement of the present invention is that the function expression used to calculate the fitness of each group is:

[0032]

[0033] Among them: Fit is the fitness of thrust distribution; r1, r2, r3, r4, r5 are constraint penalty factors.

[0034] A further improvement of the present invention is that the convergence criterion in step S5 is:

[0035] |Fit min,t -Fit min,t+1 |<0.01

[0036] Among them: Fit min,t The minimum fitness among the previous generation thrust distribution samples. When there is no previous generation thrust sample for the initial calculation, the default Fit min,t is 0; Fit min,t+1is the minimum fitness among the thrust samples of this generation.

[0037] A further improvement of the present invention is that the method of adjusting N groups of thrust distribution using the swarm intelligence optimization algorithm model to obtain N groups of offspring thrust distribution is: selecting, crossover, and mutation operations are performed on samples of N groups of thrust distribution in sequence through a genetic algorithm to obtain the N groups of offspring thrust distribution.

[0038] A further improvement of the present invention is that the segment internal force includes segment structure tensile stress, segment structure compressive stress and segment structure shear stress, and the method for judging whether the segment internal force under the optimal thrust distribution satisfies the structural force safety is:

[0039]

[0040] Where: c-max is the maximum compressive stress of the segment structure; σ t-max is the maximum tensile stress of the segment structure; τ max is the maximum shear stress of the segment structure; f c is the compressive strength of the segment structure; f t is the tensile strength of the segment structure, f s is the shear strength of the segment structure.

[0041] A further improvement of the present invention is that the finite element model established in step S1 is a three-dimensional finite element model of no less than three rings of segments including the ring to be assembled, and the parameter attributes include the segment structure size, the segments to be assembled, the through-seam / offset assembly form, and the bolt joint form.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1) The present invention combines finite element calculation and swarm intelligence optimization algorithm for iterative solution, and realizes the dynamic distribution of shield thrust by taking the internal force of the segment as the optimization target. It can effectively solve the problems of cracking and damage of the segment structure caused by poor thrust in the prior art due to the failure to consider the safety of the segment structure in thrust distribution, and is conducive to improving the construction safety, quality and efficiency of tunnel engineering.

[0044] 2) The present invention sets up an exit mechanism for the synchronous pushing and splicing operation based on the structural force safety, which can avoid outputting thrust distribution that does not meet the structural force safety requirements, and can minimize the structural risks caused by improper thrust distribution, thereby ensuring the safety of construction personnel and the quality of the project. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a flow chart of the method for dynamic thrust distribution of a shield machine based on the mechanical response of the segment structure of the present invention.

[0046] Figure 2 It is a finite element model of the segment structure of an embodiment of the present invention.

[0047] Figure 3 It is a schematic diagram of the segment division and cylinder thrust of an embodiment of the present invention.

[0048] Figure 4 It is the form of the initial thrust distribution group 1 and the calculation result of the internal force of the pipe segment according to the embodiment of the present invention.

[0049] Figure 5 It is the optimal thrust distribution form and segment internal force calculation result of the embodiment of the present invention.

[0050] Figure 6 This is the convergence process of the embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to solve the problems of cracking and damage of the segment structure caused by poor thrust due to thrust distribution in the prior art without considering the safety of the segment structure, the present invention provides a method for dynamic thrust distribution of a shield machine based on the mechanical response of the segment structure. The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0052] See also Figure 1 to Figure 6 As shown, a thrust dynamic distribution method of a shield machine based on the mechanical response of the segment structure is used for shield pushing and splicing synchronous operation. The thrust dynamic distribution method includes the following steps:

[0053] Step S1: Establish a finite element model of the segment structure, which is mainly used to calculate the internal force of the segment under the thrust of the shield cylinder. Figure 2 As shown, the structural dimensions of the shield tunnel segment in this embodiment are an outer diameter of 6.6m, an inner diameter of 5.9m, and a segment thickness of 0.35m. It adopts a staggered assembly form, and the segment rings and longitudinal seams are connected with bent bolts. The concrete grade is C55, and the segment to be assembled is the standard block ZB2. A three-dimensional finite element model containing three ring segments is established using the elastic-plastic damage constitutive model.

[0054] Step S2, setting constraints, specifically including: thrust resultant force and thrust point limit to meet the mechanical balance of shield motion, thrust upper limit of a single group of shield cylinders, and no thrust from the shield cylinders in the retraction area, i.e., zero thrust. However, no optimization target is set, and the initial thrust distribution of N groups of shield cylinders is generated by the constraint optimization algorithm. In this embodiment, the four constraints are: ① The resultant thrust of the cylinders is equal to the sum of the resistances that the shield motion needs to overcome F 阻 , is 34000kN; ② The position of the combined force of the cylinder thrust must meet the shield correction requirements, requiring the thrust action point coordinates (ex ,e y ) is (0, 0); ③ The thrust of a single group of cylinders does not exceed its performance upper limit, the thrust upper limit F limit 4187kN; ④The thrust of the retraction cylinder is 0.

[0055] like Figure 2 and Figure 3 As shown, the shield machine in this embodiment has 16 groups of cylinders, the cylinder at the arch is numbered 1, each group of cylinders is 22.5° apart, and the retraction cylinders corresponding to the ZB2 block to be assembled are numbered 11, 12, and 13; in clockwise direction, the thrust of the cylinder corresponding to the block segment to be assembled is F 回缩1 、F 回缩2 、F 回缩3 , the remaining effective thrust of the adjacent propulsion cylinder is F 推进1 、F 推进2 、F 推进 3...F 推进13 In this embodiment, the calculation expression of the constraint condition is:

[0056] ①

[0057] ②

[0058] ③0≤F 推进i ≤4187kN;

[0059] ④F 回缩1 =F 回缩2 =F 回缩3 =0.

[0060] Among them: F 推进i is the thrust of each group of remaining effective propulsion cylinders; H i V is the horizontal distance from the thrust point of the i-th group of cylinders to the center of the circle O; i is the vertical distance from the thrust point of the i-th group of cylinders to the center of the circle O; F 回缩1 、F 回缩2 、F 回缩3 It is the thrust of the retraction cylinder corresponding to the ZB2 block to be assembled.

[0061] In this embodiment, a constrained optimization algorithm based on sequential quadratic programming is used to obtain 20 (this value can be customized as needed) groups of initial thrust distribution that meet the above constraints, as shown in Table 1.

[0062] Table 1 20 groups of thrust distribution that meet the constraints

[0063]

[0064] Step S3, import the generated N groups of initial thrust distribution into the finite element model to obtain N groups of segment internal force calculation results. In this embodiment, the 20 groups of thrust distribution generated in step S2 are imported into the finite element model of the segment structure established in step S1 to obtain 20 groups of segment internal force calculation results. Figure 4 Figure (a) shows the initial thrust distribution form of Group 1 in Table 1, and Figure (b) shows the calculation results of the internal force of the segment under the initial thrust distribution of Group 1. The maximum tensile stress of the structure is 3.210MPa.

[0065] Step S4, import the N groups of segment internal force calculation results into the swarm intelligent optimization algorithm model, take the minimum segment internal force as the optimization target of thrust distribution, and use the constraint condition set in step S2 to calculate N groups of fitness, and then find the minimum fitness from the N groups of fitness. In this embodiment, the segment internal force includes the tensile stress of the segment structure, and import the 20 groups of segment internal force calculation results into the genetic algorithm module in the swarm intelligent optimization algorithm model. The calculation expression of the optimization target and fitness function is:

[0066] f(F 推进1 ,F 推进2 ,F 推进3 ,...,F 推进13 )=min(σ t-max )

[0067]

[0068] Where: f(F 推进1 ,F 推进2 ,F 推进3 ,...,F 推进13 ) is the optimization objective function; σ t-max is the maximum tensile stress of the structure calculated by the finite element model; Fit is the fitness of thrust distribution; the constraint penalty factors r1, r2, r3, r4, and r5 are all set to 5.

[0069] Step S5, judging whether the minimum fitness meets the convergence standard according to the convergence criterion: if so, the thrust distribution corresponding to the minimum fitness is taken as the optimal thrust distribution, and step S6 is executed; if not, the group intelligent optimization algorithm model is used to adjust the N groups of thrust distribution to obtain N groups of offspring thrust distribution, and then steps S3 to S5 are repeated until convergence. In this embodiment, the convergence criterion used is:

[0070] |Fit min,t -Fit min,t+1 |<0.01

[0071] Among them: Fit min,tThe minimum fitness among the previous generation thrust distribution samples. When there is no previous generation thrust sample for the initial calculation, the default Fit min,t is 0; Fit min,t+1 is the minimum fitness in this generation of thrust samples. After calculation, the minimum fitness in this generation of thrust samples is Fit min,t+1 =3.210. Substituting into the convergence criterion, we get: |Fit min,t -Fit min,t+1 |=3.210>0.01. Therefore, the result is judged as non-convergence.

[0072] When the result is non-convergence, the group intelligent optimization algorithm model needs to be used to adjust the N groups of thrust distribution. The specific adjustment method is: the genetic algorithm is used to select, crossover, and mutate the samples of the current generation of 20 groups of thrust distribution in turn to obtain the N groups of offspring thrust distribution. Specifically,

[0073] Selection operation: Calculate the selection probability P according to the fitness value of each individual i , the smaller the fitness of the sample, the greater the selection probability Pi, and the greater the probability of entering the crossover and mutation stages, so that the excellent samples are directly inherited to the next generation, as shown in the following formula:

[0074]

[0075] Where P i is the selection probability, Fit i is the fitness of the ith sample.

[0076] Crossover operation: with probability P c Mating, that is, 16 samples in this generation will participate in the crossover, and a breakpoint is randomly selected in the thrust distribution of the two groups of cylinders through single-point crossover, and the right segments of the breakpoint are exchanged to form two new offspring, and 20 samples are formed through 10 crossovers; in this embodiment, the crossover rate P c is 0.8.

[0077] Mutation operation: use a smaller probability P m The thrust distribution of the oil cylinder is mutated to form 20 new groups of samples, which are the offspring samples after completing a genetic operation. In this embodiment, the mutation probability P m is 0.1.

[0078] After 88 generations of iterations, the minimum fitness in the 88th generation thrust sample is 2.717. After 89 generations of iterations, the minimum fitness in the 89th generation thrust sample is 2.708. The difference in minimum fitness between the parent generation (i.e., the 88th generation) and the child generation (i.e., the 89th generation) is |2.717-2.708|=0.009<0.01. Therefore, it is judged to be converged, and step S6 is entered.

[0079] Step S6, determine whether the internal force of the segment under the optimal thrust distribution meets the structural force safety: if yes, output the optimal thrust distribution result; if no, exit the shield pushing and splicing synchronous operation. The internal force of the segment includes the tensile stress of the segment structure, the compressive stress of the segment structure and the shear stress of the segment structure. The method for determining whether the internal force of the segment under the optimal thrust distribution meets the structural force safety is as follows:

[0080]

[0081] Where: c-max is the maximum compressive stress of the segment structure; σ t-max is the maximum tensile stress of the segment structure; τ max is the maximum shear stress of the segment structure; f c is the compressive strength of the segment structure; f t is the tensile strength of the segment structure, f s is the shear strength of the segment structure, f c 、f t 、f s The value of is determined based on the segment structure. For example, the segment in this embodiment adopts a concrete structure numbered C55, which corresponds to a certain f c =35.5MPa, f t =2.74MPa, f s =3.55MPa value.

[0082] In this embodiment, the optimal thrust distribution obtained by calculation convergence is shown in Table 2. Figure 5 Figure (a) shows the optimal thrust distribution form, and Figure (b) shows the calculation results of the internal force of the segment under the optimal thrust distribution. c-max , σ t-max , τ max The values ​​are 8.500MPa, 2.708MPa, and 3.410MPa, respectively, which are smaller than the f of C55 concrete structure. c 、f t 、f s The value indicates that the internal force of the segment under the optimal thrust distribution meets the structural force safety. Therefore, the thrust distribution result can be output as the thrust guidance of each group of cylinders under the current push-joint synchronous construction. On the contrary, if the internal force of the segment does not meet the structural force safety, the push-joint synchronization will be exited. Through this exit mechanism, it is possible to avoid outputting thrust distribution that does not meet the structural force safety requirements, minimize the structural risks caused by improper thrust distribution, and ensure the safety of construction personnel and project quality.

[0083] Table 2 Optimal thrust distribution obtained by calculation convergence

[0084]

[0085] The present invention combines finite element calculation and swarm intelligence optimization algorithm for iterative solution, and realizes the dynamic distribution of shield thrust by taking the internal force of the segment as the optimization target. It can effectively solve the problems of cracking and damage of the segment structure caused by poor thrust in the prior art due to failure to consider the safety of the segment structure, and is conducive to improving the construction safety, quality and efficiency of tunnel engineering.

[0086] The present invention is described in detail above in conjunction with the embodiments of the accompanying drawings. A person skilled in the art can make various variations of the present invention according to the above description. Therefore, certain details in the embodiments should not constitute a limitation of the present invention, and the scope of protection of the present invention shall be defined by the scope of the attached claims.

Claims

1. A method for dynamic thrust distribution of a shield machine based on the mechanical response of the segment structure, characterized in that: For shield machine pushing and splicing synchronous operation, the thrust dynamic distribution method comprises the steps of: S1. Establish a finite element model of the segment structure to calculate the internal force of the segment under the thrust of the shield cylinder; S2, setting constraints, and generating initial thrust distribution of N groups of shield cylinders (N is a natural number greater than 1) through a constraint optimization algorithm, wherein the constraints include thrust resultant force and thrust point limit that satisfy the mechanical balance of shield motion, thrust upper limit of a single group of shield cylinders, and thrust of shield cylinders in the retraction area is zero; S3, importing the generated N groups of initial thrust distribution into the finite element model to obtain N groups of segment internal force calculation results; S4, importing the calculation results of the N groups of segment internal forces into the swarm intelligent optimization algorithm model, taking the minimum segment internal force as the optimization target of thrust distribution, and using the constraint conditions set in step S2 to calculate N groups of fitness, and then finding the minimum fitness from the N groups of fitness; S5. Determine whether the minimum fitness satisfies the convergence standard according to the convergence criterion: If yes, the thrust distribution corresponding to the minimum fitness is taken as the optimal thrust distribution, and step S6 is executed; If not, the swarm intelligence optimization algorithm model is used to adjust the N groups of thrust distribution to obtain N groups of child thrust distribution, and then steps S3 to S5 are repeated; S6. Determine whether the internal force of the segment under the optimal thrust distribution meets the structural stress safety: If yes, output the optimal thrust distribution result; If not, exit the shield pushing and splicing synchronous operation.

2. The method for dynamic thrust distribution of a shield machine based on the mechanical response of the segment structure according to claim 1, characterized in that: The expressions of the constraints set in step S2 include: 0≤F 推进i ≤F limit F 回缩1 =F 回缩2 =F 回缩3 =...=F 回缩I =0 Where: E is the total number of effective propulsion cylinders; F 推进i F is the thrust of each group of effective propulsion cylinders; 阻 H is the resistance that the shield needs to overcome in advancing; i V is the horizontal distance from the thrust point of the i-th group of cylinders to the center of the circle O; i is the vertical distance from the thrust point of the i-th group of cylinders to the center of the circle O; (e x ,e y ) is the coordinate of the resultant force point required to control the shield posture, that is, the horizontal eccentricity e of the resultant force x and vertical eccentricity e y ; F limit F is the upper limit of the thrust of a single set of propulsion cylinders; 回缩1 、F 回缩2 、F 回缩3 ,...F 回缩I is the thrust of the cylinder in the retraction area corresponding to the segment to be assembled, both are 0, and I is the number of cylinders in the retraction area corresponding to the segment to be assembled.

3. The method for dynamic thrust distribution of a shield machine based on the mechanical response of the segment structure according to claim 2, characterized in that: The segment internal force includes the segment structure tensile stress σ t-max , the calculation expression for optimizing thrust distribution with the minimum internal force of the segment is: f(F 推进1 ,F 推进2 ,F 推进3 ,...,F 推进E )=min(σ t-max ) Where: f(F 推进1 ,F 推进2 ,F 推进3 ,...,F 推进E ) is the optimization objective function; E is the total number of effective propulsion cylinders.

4. The method for dynamic thrust distribution of a shield machine based on the mechanical response of the segment structure according to claim 3, characterized in that: The function expression used to calculate the fitness of each group is: Among them: Fit is the fitness of thrust distribution; r1, r2, r3, r4, r5 are constraint penalty factors.

5. The method for dynamic thrust distribution of a shield machine based on the mechanical response of the segment structure according to claim 4, characterized in that: The convergence criterion in step S5 is: |Fit min,t -Fit min,t+1 |<0.01 Among them: Fit min,t The minimum fitness among the previous generation thrust distribution samples. When there is no previous generation thrust sample for the initial calculation, the default Fit min,t is 0; Fit min,t+1 is the minimum fitness among the thrust samples of this generation.

6. The method for dynamic thrust distribution of a shield machine based on the mechanical response of the segment structure according to claim 1, characterized in that: The method of adjusting N groups of thrust distribution using the swarm intelligence optimization algorithm model to obtain N groups of offspring thrust distribution is: sequentially performing selection, crossover, and mutation operations on samples of N groups of thrust distribution through a genetic algorithm to obtain the N groups of offspring thrust distribution.

7. The method for dynamic thrust distribution of a shield machine based on the mechanical response of a segment structure according to claim 1, characterized in that: The segment internal force includes the segment structure tensile stress, segment structure compressive stress and segment structure shear stress. The method for judging whether the segment internal force under the optimal thrust distribution satisfies the structural force safety is as follows: Where: c-max is the maximum compressive stress of the segment structure; σ t-max is the maximum tensile stress of the segment structure; τ max is the maximum shear stress of the segment structure; f c is the compressive strength of the segment structure; f t is the tensile strength of the segment structure, f s is the shear strength of the segment structure.

8. The method for dynamic thrust distribution of a shield machine based on the mechanical response of a segment structure according to claim 1, characterized in that: The finite element model established in step S1 is a three-dimensional finite element model of at least three rings of segments including the ring to be assembled, and the parameter attributes include the segment structure size, the segments to be assembled, the through-seam / offset assembly form, and the bolt joint form.

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