Servo type supporting foundation pit mechanical calculation model considering construction and axial force optimization method

Abstract

The invention discloses a construction-considered servo type supporting foundation pit mechanical calculation model and an axial force optimization method, and the calculation model comprises the steps: solving a basic mechanical equilibrium equation, and solving the basic mechanical equilibrium equation to obtain the lateral displacement of an enclosure wall body in each construction step and the axial force of each support; the axial force optimization method comprises the following steps: S1, establishing an initial system; s2, optimized support unloading is carried out; and S3, optimizing support loading. The method has the advantages that automatic adjustment and optimization of the servo type support axial force can be achieved through programming, so that the design calculation efficiency is improved, a theoretical basis is provided for determining the control axial force of the servo type support in actual engineering application, and the foundation pit deformation control effect is enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of deformation control and design calculation of foundation pit engineering, and in particular to a servo-type support foundation pit mechanical calculation model and an axial force optimization method considering construction. Background Art

[0002] With the rapid development of my country's economy and the advancement of urbanization, urban ground land is becoming increasingly scarce, and the focus of urban development has shifted to underground space. As a preparatory project for the construction of various underground structures, foundation pit engineering has continued to emerge in the wave of underground space development, and has gradually developed towards the characteristics of deep, large, and close. The foundation pit engineering system and the surrounding environment are becoming more and more complex, and the deformation of the foundation pit has become more and more strictly controlled.

[0003] In this context, servo supports that can autonomously control the internal axial force of the support have been gradually promoted and applied in deep foundation pit projects with high difficulty in deformation control, especially in deep foundation pits in soft soil. Different from the passive working state of conventional steel supports in the support system, servo supports can actively apply reaction force to the surrounding structure through real-time compensation and adjustment of the axial force, thereby achieving effective control of foundation pit deformation.

[0004] For servo supports, how to adjust the control axial force during the actual construction process has a key impact on the control effect of foundation pit deformation. However, there is currently a lack of a mature and theoretically based optimization design method for determining the control axial force of servo supports in actual engineering applications.

[0005] Therefore, based on the force and deformation calculation theory of servo-type support foundation pit, a servo-type support foundation pit mechanical calculation model and axial force optimization method considering construction are proposed, which will be of great significance to the promotion and application of servo support and the further development of deformation control theory of deep foundation pit engineering. Summary of the invention

[0006] The purpose of the present invention is to provide a servo-type support foundation pit mechanical calculation model and axial force optimization method taking construction into consideration based on the above-mentioned deficiencies of the prior art. The calculation model includes the solution of the basic mechanical equilibrium equation. By solving the basic mechanical equilibrium equation, the lateral displacement of the retaining wall in each construction step and the axial force of each support are obtained. Automatic adjustment and optimization of the servo-type support axial force can be achieved through programming, thereby improving the design calculation efficiency and providing a theoretical basis for determining the control axial force of the servo-type support in actual engineering applications, so as to enhance the foundation pit deformation control effect.

[0007] The purpose of the present invention is achieved by the following technical solutions:

[0008] A mechanical calculation model for a servo - supported foundation pit considering construction, the calculation model includes solving the basic mechanical equilibrium equation, and by solving the basic mechanical equilibrium equation, the lateral displacement of the retaining wall at each construction step and the axial force of each support are obtained;

[0009] Based on the vertical elastic foundation beam model, the basic mechanical equilibrium equation is expressed as:

[0010]

[0011] In the formula, EI is the flexural rigidity of the retaining wall; y(z) is the lateral displacement of the retaining wall at depth z; q(z) is the water and soil load acting at depth z; p(z) is the axial force of the servo - type support acting at depth z; k strut (z) is the stiffness of the non - servo - type support installed at depth z; y0(z) is the lateral displacement that the retaining wall has already undergone before the installation of the non - servo - type support installed at depth z, that is, the initial displacement of the support installation; k soil (z) is the stiffness of the passive - zone soil spring located at depth z;

[0012] The basic mechanical equilibrium equation is solved by the finite - difference method, and its matrix form is expressed as:

[0013] [K][Y]=[Q]-[F s +[F c ;

[0014] In the formula, [K] is the system stiffness matrix representing the stiffness of the retaining wall, the stiffness of the support, and the stiffness of the passive - zone soil spring; [Y] is the displacement matrix representing the lateral displacement of the retaining wall; [Q] is the water and soil load matrix; [F s is the servo - type support axial - force matrix; [F c is the support axial - force correction matrix representing the construction process.

[0015] An axial - force optimization method for a mechanical calculation model of a servo - supported foundation pit considering construction, the axial - force optimization method includes the following steps:

[0016] S1: Establish an initial system;

[0017] S2: Optimize support unloading;

[0018] S3: Optimize support loading.

[0019] In step S1, the method for establishing the initial system includes the following steps:

[0020] S1.1: According to the design conditions, determine various geometric and physical - mechanical parameters required for the calculation model;

[0021] S1.2: Determine whether the current construction step is the first construction step. If it is, directly proceed to the next step; if not, determine the initial displacement for installing each support based on the calculation results of the completed construction steps.

[0022] S1.3: Determine the control axial force of each servo-type support in the current construction step. The determination method is as follows:

[0023] For the servo-type supports existing in the previous construction step, take the optimized control axial force or the calculated axial force determined in the previous construction step; for the servo-type supports installed in the current construction step, the prestress value needs to be preset in advance. If not preset, the value is taken as 0.

[0024] S1.4: Calculate the lateral displacement of the retaining wall and the axial force of each support in the current construction step.

[0025] S1.5: End the establishment of the initial system and enter the optimization of support unloading.

[0026] In step S2, the optimization method for support unloading includes the following steps:

[0027] S2.1: Locate each installed support and classify them according to concrete supports, non-servo-type supports, and servo-type supports to obtain the depth of the position where each support is located and the corresponding classification labels [(z1, L1), (z2, L2),..., (z i , L i ),..., (z n , L n )];

[0028] where z i is the depth of the installation position of the i-th support, and L i is the support type of the i-th support;

[0029] S2.2: Taking the concrete support as the boundary, divide the retaining wall into m regions A1, A2,..., A m ;

[0030] S2.3: Locate the position h hm where the maximum lateral displacement δ t of the retaining wall is located, and the region A t where it is located;

[0031] S2.4: Determine whether there is an adjacent region A t to region A t-1 or A t+1 . If not, execute step S2.9. If so, continue to execute the subsequent steps;

[0032] S2.5: Determine At-1 、A t+1 Whether there is a servo support with a controlled axial force greater than 0 in the area. If not, execute step S2.9. If so, classify the supports that meet the conditions into set U and continue to execute the subsequent steps;

[0033] S2.6: Determine whether set U is an empty set. If so, execute step S2.9; if not, continue to execute the subsequent steps;

[0034] S2.7: Calculate the relative distance Δh t between each support j and h j in set U as Δh j = |z t - h

[0035] |, sort them from near to far, and execute step S2.8 for the nearest support k;

[0036] S2.8: Decrease the controlled axial force of support k in steps of ΔF, and recalculate the lateral displacement of the retaining wall after unloading and the axial force magnitudes of each support. Determine whether the calculation results meet the following conditions: hm Condition 1: The maximum lateral displacement δ hm ' of the retaining wall after unloading is less than the maximum lateral displacement δ

[0037] of the retaining wall before unloading; i Condition 2: The axial force magnitudes of each support meet the safety design requirements F i,min ∈ [F i,max ;

[0038] where, F i is the axial force of the i-th support, F i,min is the minimum value that meets the safety design requirements for the i-th support, and F i,max is the maximum value that meets the safety design requirements for the i-th support;

[0039] Condition 3: The maximum lateral displacement δ hm ' of the retaining wall after unloading is greater than the lateral displacement control target δ control of the retaining wall;

[0040] If all the above conditions are met, end the unloading of support k and return to step S2.3;

[0041] If condition 1 or condition 2 is not met, restore the controlled axial force of support k to the controlled axial force before this step of unloading, end the unloading of support k, remove support k from set U, and return to step S2.6;

[0042] If only condition 3 is not met, end the unloading of support k and execute step S2.9;

[0043] S2.9: End the optimization of support unloading and enter the optimization of support loading.

[0044] In step S3, the support loading optimization method includes the following steps:

[0045] S3.1: Locate the maximum lateral displacement of the retaining wall δ hm Location t , and the area A t ;

[0046] S3.2: Judge A t Whether there is a servo-type support with a control axis force greater than 0 in the area, if not, execute step S3.6; if so, classify the supports that meet the conditions into set V and continue to execute subsequent steps;

[0047] S3.3: Determine whether the set V is an empty set. If so, execute step S3.6; if not, continue to execute subsequent steps;

[0048] S3.4: Calculate the support j and h of each path in the set V t The relative distance Δh j =|z j -h t |, and sort from near to far, and execute step S3.5 for the nearest support k;

[0049] S3.5: Increase the control axial force of support k according to the step size of ΔF, and recalculate the lateral displacement of the retaining wall and the axial force of each support after loading to determine whether the calculation results meet the following conditions:

[0050] Condition 1: Maximum lateral displacement of the retaining wall after loading δ hm ' is less than the maximum lateral displacement of the retaining wall before loading δ hm ;

[0051] Condition 2: The axial force of each support meets the safety design requirements F i ∈[F i,min ,F i,max ];

[0052] Condition 3: Maximum lateral displacement of the retaining wall after loading δ hm 'Greater than the lateral displacement control target of the retaining wall δ control ;

[0053] If all the above conditions are met, the loading of support k is terminated and the process returns to step S3.1;

[0054] If condition 1 or condition 2 is not satisfied, the controlled axial force of support k is restored to the controlled axial force before this step of loading, the loading of support k is ended, support k is removed from the set V, and step S3.3 is returned;

[0055] If only condition 3 is not satisfied, the loading of support k is ended and step S3.6 is executed;

[0056] S3.6: End the optimization of support loading and output the controlled axial forces of each servo-type support determined by optimization for the current construction step.

[0057] The advantages of the present invention are: based on a simplified physical and mechanical model for design and calculation, with high calculation efficiency and a solid and reliable theoretical basis; for each construction step of foundation pit excavation, on the premise of ensuring the structural performance such as the bearing capacity and stability of each support, aiming at reducing the lateral displacement of the retaining wall, the controlled axial forces of each servo-type support are refined and iteratively optimized to strictly control the deformation during the whole process of foundation pit excavation. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a schematic diagram of the mechanical calculation model of the servo-type supported foundation pit considering construction of the present invention;

[0059] Figure 2 It is a flowchart of the axial force optimization method for the mechanical calculation model of the servo-type supported foundation pit considering construction of the present invention;

[0060] Figure 3 It is a schematic diagram of the initial system establishment process of the present invention;

[0061] Figure 4 It is a schematic diagram of the support unloading optimization process of the present invention;

[0062] Figure 5 It is a schematic diagram of the support loading optimization process of the present invention;

[0063] As Figures 1 to 5 shown, the marks in the figure are respectively represented as:

[0064] The first non-servo support 1, the second non-servo support 2, the servo support 3, and the retaining wall 4;

[0065] The initial installation displacement d1 of the first non-servo support, the initial installation displacement d2 of the second non-servo support, the excavation surface a, the passive zone soil spring b, and the water and soil load c. DETAILED DESCRIPTION OF THE INVENTION

[0066] The following further details the features of the present invention and other related features in conjunction with the accompanying drawings through embodiments for the understanding of those skilled in the same industry:

[0067] Embodiment: As Figure 1As shown in the figure, this embodiment relates to a mechanical calculation model for a servo-supported foundation pit considering construction. The calculation model mainly includes the solution of the basic mechanical equilibrium equation. By solving the basic mechanical equilibrium equation, the lateral displacement of the retaining wall at each construction step and the axial force of each support are obtained.

[0068] Based on the vertical elastic foundation beam model, the basic mechanical equilibrium equation is expressed as:

[0069]

[0070] In the formula, EI is the flexural rigidity of the retaining wall; y(z) is the lateral displacement of the retaining wall at depth z; q(z) is the water and soil load acting at depth z; p(z) is the axial force of the servo support acting at depth z; k strut (z) is the stiffness of the non-servo support installed at depth z; y0(z) is the lateral displacement that the retaining wall has already undergone before the installation of the non-servo support installed at depth z, that is, the initial displacement of the support installation; k soil (z) is the stiffness of the passive zone soil spring located at depth z.

[0071] The basic mechanical equilibrium equation is solved by the finite difference method, and its matrix form is expressed as:

[0072] [K][Y] = [Q] - [F s + [F c ;

[0073] In the formula, [K] is the system stiffness matrix representing the stiffness of the retaining wall, the stiffness of the support, and the stiffness of the passive zone soil spring; [Y] is the displacement matrix representing the lateral displacement of the retaining wall; [Q] is the water and soil load matrix; [F s is the servo support axial force matrix; [F c is the support axial force correction matrix representing the construction process.

[0074] Refer to Figure 1 As shown in the figure, the outside of the retaining wall 4 bears the water and soil load c, and the first non-servo support 1, the servo support 3, and the second non-servo support 2 are successively arranged from top to bottom inside above the excavation surface a. The soil mass below the excavation surface a is regarded as the passive zone soil spring b.

[0075] As Figures 2 to 5 shown in the figure, this embodiment also relates to an axial force optimization method for a mechanical calculation model of a servo-supported foundation pit considering construction. The axial force optimization method mainly includes the following steps:

[0076] S1: Establish an initial system.

[0077] Among them, as Figure 3 shown in the figure, the method for establishing the initial system includes the following steps:

[0078] S1.1: Determine various geometric, physical and mechanical parameters required for the calculation model according to the design conditions.

[0079] S1.2: Judge whether the current construction step is the first construction step. If so, directly enter the next step; if not, determine the initial installation displacement of each support according to the calculation results of the completed construction steps.

[0080] S1.3: Determine the control axial force of each servo support in the current construction step. The determination method is as follows:

[0081] For the servo supports existing in the previous construction step, take the optimized or calculated axial force determined in the previous construction step; for the servo supports installed in the current construction step, the prestress value needs to be preset. If not preset, the value is taken as 0.

[0082] S1.4: Calculate the lateral displacement of the retaining wall and the axial force of each support in the current construction step.

[0083] S1.5: End the establishment of the initial system and enter the optimization of support unloading.

[0084] S2: Optimize support unloading.

[0085] Among them, as Figure 4 shown, the optimization method of support unloading includes the following steps:

[0086] S2.1: Locate each installed support and classify them according to concrete supports, non-servo supports and servo supports to obtain the depth of the position where each support is located and the corresponding classification labels [(z1, L1), (z2, L2),..., (z i , L i ),..., (z n , L n )];

[0087] Among them, z i is the depth of the installation position of the i-th support, and L i is the support type of the i-th support.

[0088] S2.2: Take the concrete support as the boundary and divide the retaining wall into m regions A1, A2,..., A m .

[0089] S2.3: Locate the position h hm where the maximum lateral displacement δ t of the retaining wall is located, and the region A t where it is located.

[0090] S2.4: Determine whether there is area A t and its adjacent area A t-1 or A t+1 . If not, execute step S2.9; if so, continue to execute the subsequent steps.

[0091] S2.5: Determine whether there is a servo - type support with a controlled axial force greater than 0 within area A t-1 and area A t+1 . If not, execute step S2.9; if so, classify the supports that meet the conditions into set U and continue to execute the subsequent steps.

[0092] S2.6: Determine whether set U is an empty set. If so, execute step S2.9; if not, continue to execute the subsequent steps.

[0093] S2.7: Calculate the relative distance Δh t between each support j and h j in set U, where Δh j = |z t - h

[0094] |, sort them from near to far, and execute step S2.8 for the nearest support k. S2.8: Reduce the controlled axial force of support k (i.e., unloading operation) in accordance with the step size of ΔF, and recalculate the lateral displacement of the retaining wall after unloading and the axial force magnitudes of each support. Determine whether the calculation results meet the following conditions:

[0095] Condition 1: The maximum lateral displacement δ hm ' of the retaining wall after unloading is less than the maximum lateral displacement δ hm of the retaining wall before unloading;

[0096] Condition 2: The axial force magnitudes of each support meet the safety design requirements F i ∈[F i,min , F i,max ;

[0097] where F i is the axial force of the i - th support, F i,min is the minimum value that meets the safety design requirements for the i - th support, and F i,max is the maximum value that meets the safety design requirements for the i - th support;

[0098] Condition 3: The maximum lateral displacement δ hm ' of the retaining wall after unloading is greater than the lateral displacement control target δ control of the retaining wall;

[0099] If all of the above conditions are met, end the unloading of support k and return to step S2.3;

[0100] If condition 1 or condition 2 is not satisfied, restore the control axial force of support k to the control axial force before unloading in this step, end the unloading of support k, remove support k from set U, and return to step S2.6;

[0101] If only condition 3 is not satisfied, end the unloading of support k and execute step S2.9.

[0102] S2.9: End the optimization of support unloading and enter the optimization of support loading.

[0103] S3: Optimize support loading.

[0104] Among them, as Figure 5 shown, the optimization method of support loading includes the following steps:

[0105] S3.1: Locate the position h hm where the maximum lateral displacement δ t of the retaining wall is located, and the area A t .

[0106] S3.2: Judge whether there is a servo support with a control axial force greater than 0 in area A t . If not, execute step S3.6; if so, classify the eligible supports into set V and continue to execute the subsequent steps.

[0107] S3.3: Judge whether set V is an empty set. If so, execute step S3.6; if not, continue to execute the subsequent steps.

[0108] S3.4: Calculate the relative distance Δh t between each support j in set V and h j =|z j -h t |, sort them from near to far, and execute step S3.5 for the nearest support k.

[0109] S3.5: Increase the control axial force of support k (i.e., the loading operation) in the step of ΔF, and recalculate the lateral displacement of the retaining wall after loading and the axial force of each support. Judge whether the calculation results meet the following conditions:

[0110] Condition 1: The maximum lateral displacement δ hm ' of the retaining wall after loading is less than the maximum lateral displacement δ hm of the retaining wall before loading;

[0111] Condition 2: The axial force of each support meets the safety design requirements F i ∈[F i,min ,F i,max ;

[0112] Condition 3: The maximum lateral displacement δ of the retaining wall after loading hm 'is greater than the control target δ of the lateral displacement of the retaining wall control ;

[0113] If all the above conditions are met, end the loading of the strut k and return to step S3.1;

[0114] If condition 1 or condition 2 is not met, restore the control axial force of the strut k to the control axial force before this step of loading, end the loading of the strut k, remove the strut k from the set V, and return to step S3.3;

[0115] If only condition 3 is not met, end the loading of the strut k and execute step S3.6.

[0116] S3.6: End the optimization of the strut loading and output the control axial forces of each servo strut optimized for the current construction step.

[0117] The beneficial technical effects of this embodiment are as follows: Based on a simplified physical and mechanical model for design and calculation, it has high calculation efficiency and a solid and reliable theoretical basis; for each construction step of the foundation pit excavation, on the premise of ensuring the structural performance such as the bearing capacity and stability of each strut, with the goal of reducing the lateral displacement of the retaining wall, the control axial forces of each servo strut are refined and iteratively optimized to achieve strict control of the deformation during the whole process of foundation pit excavation.

[0118] Although the above embodiments have described in detail the concept and embodiments of the present invention with reference to the accompanying drawings, those of ordinary skill in the art can recognize that various improvements and transformations can still be made to the present invention without departing from the scope defined by the claims, so they will not be elaborated here one by one.

Claims

1. A mechanical calculation model for a servo-supported foundation pit considering construction, characterized in that The calculation model includes the solution of the basic mechanical equilibrium equations. By solving the basic mechanical equilibrium equations, the lateral displacement of the retaining wall for each construction step and the axial force of each support are obtained; Based on the vertical elastic foundation beam model, the basic mechanical equilibrium equation is expressed as: Wherein, EI is the flexural rigidity of the retaining wall; y(z) is the lateral displacement of the retaining wall at depth z; q(z) is the water and soil load acting at depth z; p(z) is the axial force of the servo support acting at depth z; k strut (z) is the stiffness of the non-servo support installed at depth z; y0(z) is the lateral displacement that has occurred in the retaining wall before the installation of the non-servo support installed at depth z, that is, the initial displacement of the support installation; k soil (z) is the stiffness of the passive zone soil spring located at depth z; The basic mechanical equilibrium equation is solved using the finite difference method, and its matrix form is expressed as: [K][Y] = [Q] - [F s + [F c ; In the formula, [K] is the system stiffness matrix representing the stiffness of the retaining wall, the stiffness of the support, and the stiffness of the soil spring in the passive zone; [Y] is the displacement matrix representing the lateral displacement of the retaining wall; [Q] is the water and soil load matrix; [F s is the servo-type support axial force matrix; [F c is the support axial force correction matrix representing the construction process.

2. The axial force optimization method of a servo-type supporting foundation pit mechanical calculation model considering construction according to claim 1, characterized in that The axial force optimization method includes the following steps: S1: Establish an initial system; S2: Optimize support unloading; S3: Optimize support loading.

3. The axial force optimization method of a servo-supported foundation pit mechanical calculation model considering construction as claimed in claim 2, characterized in that In step S1, the method for establishing the initial system includes the following steps: S1.1: According to the design conditions, determine various geometric and physical-mechanical parameters required for the calculation model; S1.2: Determine whether the current construction step is the first construction step. If so, directly proceed to the next step; if not, determine the initial displacement of the installation of each support according to the calculation results of the completed construction steps; S1.3: Determine the control axial force magnitude of each servo support in the current construction step. The determination method is as follows: For the servo supports existing in the previous construction step, take the control axial force or calculated axial force optimized in the previous construction step; for the servo supports installed in the current construction step, the prestress magnitude needs to be preset in advance. If not preset, the value is taken as 0; S1.4: Calculate the lateral displacement of the retaining wall and the axial force magnitude of each support in the current construction step; S1.5: End the establishment of the initial system and enter the optimization of support unloading.

4. The axial force optimization method of a servo-supported foundation pit mechanical calculation model considering construction according to claim 3, characterized in that In step S2, the method for optimizing support unloading includes the following steps: S2.1: Locate each installed support and classify them into concrete supports, non-servo supports, and servo supports to obtain the depths of the locations where each support is located and the corresponding classification labels [(z1, L1), (z2, L2), …, (z i , L i ), …, (z n , L n )]; where z i is the depth where the i-th support is installed, and L i is the support type of the i-th support; S2.2: Taking the concrete support as the boundary, divide the retaining wall into m regions A1, A2,..., A along the depth direction m ; S2.3: Locate the maximum lateral displacement δ of the retaining wall hm at the position h t , and in the area A t ; S2.4: Determine whether there is area A t adjacent area A t-1 or A t+1 , if not, execute step S2.9, if so, continue to execute the subsequent steps; S2.5: Determine A t-1 and A t+1 Whether there is a servo support with a controlled axial force greater than 0 in the area. If not, execute step S2.

9. If so, classify the supports that meet the conditions into set U and continue to execute the subsequent steps; S2.6: Determine whether the set U is an empty set. If so, execute step S2.9; if not, continue to execute the subsequent steps; S2.7: Calculate the relative distance Δh between each support j and h within the set U t and sort them from the nearest to the farthest. Perform step S2.8 on the nearest support k; j = |z j - h t |, and sort them from the nearest to the farthest. Perform step S2.8 on the nearest support k; S2.8: According to the step size of ΔF, reduce the control axial force of support k, and recalculate the lateral displacement of the retaining wall and the axial force magnitude of each support after unloading. Determine whether the calculation results meet the following conditions: Condition 1: The maximum lateral displacement δ of the retaining wall after unloading hm is less than the maximum lateral displacement δ of the retaining wall before unloading hm ; Condition 2: The axial force of each support meets the safety design requirement F i ∈[F i,min , F i,max ; Among them, F i is the axial force of the i-th support, and F i,min is the minimum value of the i-th support that meets the safety design requirements, and F i,max is the maximum value of the i-th support that meets the safety design requirements; Condition 3: The maximum lateral displacement δ of the retaining wall after unloading hm is greater than the control target δ of the lateral displacement of the retaining wall control ; If all the above conditions are met, end the unloading of support k and return to step S2.3; If condition 1 or condition 2 is not met, restore the control axial force of support k to the control axial force before this step of unloading, end the unloading of support k, remove support k from the set U, and return to step S2.6; If only condition 3 is not met, end the unloading of support k and execute step S2.9; S2.9: End the optimization of support unloading and enter the optimization of support loading.

5. The axial force optimization method of a servo-supported foundation pit mechanical calculation model considering construction as claimed in claim 4, characterized in that In step S3, the method for optimizing support loading includes the following steps: S3.1: Locate the maximum lateral displacement δ of the retaining wall hm at the position h t , and in the area A t ; S3.2: Determine A t Whether there is a servo support with a control axial force greater than 0 in the area. If not, execute step S3.6; if so, classify the supports that meet the conditions into set V and continue to execute the subsequent steps; S3.3: Determine whether the set V is an empty set. If so, execute step S3.6; if not, continue to execute the subsequent steps; S3.4: Calculate the relative distance Δh between each support j and h within the set V t and sort them from the nearest to the farthest, and perform step S3.5 on the nearest support k; j = |z j - h t | S3.5: According to the step size of ΔF, increase the control axial force of support k, and recalculate the lateral displacement of the retaining wall and the axial force magnitude of each support after loading. Determine whether the calculation results meet the following conditions: Condition 1: The maximum lateral displacement δ of the retaining wall after loading hm is less than the maximum lateral displacement δ of the retaining wall before loading hm ; Condition 2: The axial force of each support meets the safety design requirement F i ∈[F i,min , F i,max ; Condition 3: The maximum lateral displacement δ of the retaining wall after loading hm is greater than the control target δ of the lateral displacement of the retaining wall control ; If all the above conditions are met, end the loading of support k and return to step S3.1; If condition 1 or condition 2 is not met, restore the control axial force of support k to the control axial force before this step of loading, end the loading of support k, remove support k from the set V, and return to step S3.3; If only condition 3 is not satisfied, the loading of the support k is ended, and step S3.6 is executed; S3.6: End the optimization of the support loading, and output the controlled axial forces of each servo-type support optimized and determined for the current construction step.

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